The role of phytic acid in legumes: antinutrient or beneficial function?

This review describes the present state of knowledge about phytic acid (phytate), which is often present in legume seeds. The antinutritional effects of phytic acid primarily relate to the strong chelating associated with its six reactive phosphate groups. Its ability to complex with proteins and particularly with minerals has been a subject of investigation from chemical and nutritional viewpoints. The hydrolysis of phytate into inositol and phosphates or phosphoric acid occurs as a result of phytase or nonenzymatic cleavage. Enzymes capable of hydrolysing phytates are widely distributed in micro-organisms, plants and animals. Phytases act in a stepwise manner to catalyse the hydrolysis of phytic acid. To reduce or eliminate the chelating ability of phytate, dephosphorylation of hexa- and penta-phosphate forms is essential since a high degree of phosphorylation is necessary to bind minerals. There are several methods of decreasing the inhibitory effect of phytic acid on mineral absorption (cooking, germination, fermentation, soaking, autolysis). Nevertheless, inositol hexaphosphate is receiving increased attention owing to its role in cancer prevention and/or therapy and its hypocholesterolaemic effect.

Suppression of colonic cancer by dietary phytic acid.

Large differences exist between human populations in the frequency of colonic cancer. Epidemiological evidence indicates that these differences are strongly influenced by country of residence, and a negative correlation has been found between the fiber content of the diet and frequency of colonic cancer. This has prompted the hypothesis that high-fiber diets are in some way protective. However, reanalysis of the dietary data provides equally strong support for the hypothesis that the protective element may be phytic acid (inositol hexaphosphate). This heat- and acid-stable substance is present in high concentration in many food items, including cereal grains, nuts, and seeds. Phytic acid forms chelates with various metals and suppresses damaging iron-catalyzed redox reactions. Inasmuch as colonic bacteria have been shown to produce oxygen radicals in appreciable amounts, dietary phytic acid might suppress oxidant damage to intestinal epithelium and neighboring cells. Indeed, rapidly accumulating data from animal models indicate that dietary supplementation with phytic acid may provide substantial protection against experimentally induced colonic cancer. Should further investigations yield additional support for this hypothesis, purposeful amplification of dietary phytic acid content would represent a simple method for reducing the risk of colonic carcinogenesis.

Phytate in foods and significance for humans: food sources, intake, processing, bioavailability, protective role and analysis.

The article gives an overview of phytic acid in food and of its significance for human nutrition. It summarises phytate sources in foods and discusses problems of phytic acid/phytate contents of food tables. Data on phytic acid intake are evaluated and daily phytic acid intake depending on food habits is assessed. Degradation of phytate during gastro-intestinal passage is summarised, the mechanism of phytate interacting with minerals and trace elements in the gastro-intestinal chyme described and the pathway of inositol phosphate hydrolysis in the gut presented. The present knowledge of phytate absorption is summarised and discussed. Effects of phytate on mineral and trace element bioavailability are reported and phytate degradation during processing and storage is described. Beneficial activities of dietary phytate such as its effects on calcification and kidney stone formation and on lowering blood glucose and lipids are reported. The antioxidative property of phytic acid and its potentional anticancerogenic activities are briefly surveyed. Development of the analysis of phytic acid and other inositol phosphates is described, problems of inositol phosphate determination and detection discussed and the need for standardisation of phytic acid analysis in foods argued.

Dietary suppression of colonic cancer. Fiber or phytate?

The incidence of colonic cancer differs widely between various human populations. It has been suggested that dietary fiber content is of utmost importance and is inversely related to the occurrence of colonic cancer. However, high-fiber diets are not always correlated with low frequency of colonic cancer, suggesting the involvement of additional dietary constituents. Inositol hexaphosphate (phytic acid) is an abundant plant seed component present in many, but not all, fiber-rich diets. The authors have found that phytic acid is a potent inhibitor of iron-mediated generation of the hazardous oxidant, hydroxyl radical. Herein, the authors propose that inhibition of intracolonic hydroxyl radical generation, via the chelation of reactive iron by phytic acid, may help explain the suppression of colonic carcinogenesis and other inflammatory bowel diseases by diets rich in phytic acid.

Effect of phytic acid on the absorption, distribution, and endogenous excretion of zinc in rats.

Zinc metabolism in male rats was studied by combining nutritional balance methods with an analysis of 65Zn kinetics. The rats, two groups of 84 each, were fed zinc-adequate diets (33 ppm Zn) with either 0 (basal) or 2% phytic acid added as sodium phytate. A fourth-order exponential function described the time-course of 65Zn in plasma, and compartmental models were developed accordingly. Plasma zinc exchanged more rapidly with zinc in liver and kidneys than it did with zinc in testes, skeletal muscle, or bone. Total body zinc content (2.6 mg/100 g live body weight) measured chemically was about 9 times higher than estimates of exchangeable zinc in the body. Whole-body retention of 65Zn was higher and endogenous fecal zinc excretion was lower in rats fed phytate than in those fed the basal diet; these responses to phytate may reflect a homeostatic adjustment to decreased absorption of zinc. Respective values for apparent absorption and true absorption of zinc were 13 and 32% of zinc intake in rats fed phytate, and 19 and 46% of zinc intake in rats fed the basal diet. When whole grains or mature seeds constitute a major portion of the diet, the phytate: zinc molar ratio may approach that (60:1) used in our study. Whether or not phytic acid occurring naturally in foods affects zinc metabolism to the same extent as sodium phytate can not be determined from our study.

Ascorbic acid prevents the dose-dependent inhibitory effects of polyphenols and phytates on nonheme-iron absorption.

The effects of maize-bran phytate and of a polyphenol (tannic acid) on iron absorption from a white-bread meal were tested in 199 subjects. The phytate content was varied by adding different concentrations of phytate-free and ordinary maize bran. Iron absorption decreased progressively when maize bran containing increasing amounts of phytate phosphorous (phytate P) (from 10 to 58 mg) was given. The inhibitory effect was overcome by 30 mg ascorbic acid. The inhibitory effects of tannic acid (from 12 to 55 mg) were also dose dependent. Studies suggested that greater than or equal to 50 mg ascorbic acid would be required to overcome the inhibitory effects on iron absorption of any meal containing greater than 100 mg tannic acid. Our findings indicate that it may be possible to predict the bioavailability of iron in a diet if due account is taken of the relative content in the diet of the major promoters and inhibitors of iron absorption.

Phytate levels and bone parameters: a retrospective pilot clinical trial.

This study evaluated the relationship between phytate urinary levels and bone characteristics in a large population of postmenopausal women. The study population consisted of 180 postmenopausal women who participated in a descriptive cross-sectional study. A urine sample was collected from each subject to determine phytate levels and the volunteers were divided into two groups according to phytate urinary concentration (i.e., low and high levels). Bone mineral density was determined in the lumbar spine and femoral neck of groups with low and high phytate urinary levels. Urinary levels of phytate were linked to dietary phytate consumption. Hence, bone mineral density values were significantly higher in the lumbar spines and femoral necks of women who consumed high levels of phytate than in women with low urinary phytate concentrations. Higher urinary levels of phytate correlated with higher bone mineral density in the lumbar spine and femoral necks of postmenopausal women. This finding demonstrates the potential use of phytate in the treatment of bone related diseases, as it uses a mechanism of action similar to some bisphosphonates.

A study on degradation kinetics of ascorbic acid in amla (Phyllanthus emblica L.) during cooking.

The kinetics of ascorbic acid degradation in amla (Phyllanthus emblica L.) as well as in pure ascorbic acid solutions at initial concentrations present in amla over a temperature range of 50-120 degrees C (steady-state temperature) has been studied. The ascorbic acid degradation followed first-order reaction kinetics where the rate constant increased with an increase in temperature. The temperature dependence of degradation was adequately modeled by the Arrhenius equation. The activation energies were found to be 4.09 kcal/mole for amla and 4.49 kcal/mole for pure vitamin solution. The degradation kinetics of ascorbic acid was also evaluated in normal open pan cooking, pressure-cooking and a newly developed and patented fuel-efficient EcoCooker (unsteady state heating process). A mathematical model was developed using the steady-state kinetic parameters obtained to predict the losses of ascorbic acid from the time-temperature data of the unsteady state heating processing method. The results obtained indicate the ascorbic acid degradation is of a similar order of magnitude in all the methods of cooking.

Genotoxicity and cell transformation studies with sorbates in Syrian hamster embryo fibroblasts.

Sorbic acid, sodium sorbate and potassium sorbate were tested for their genotoxic potential in the Syrian hamster embryo (SHE) fibroblast micronucleus assay and the SHE cell transformation test in vitro. Sorbic acid and potassium sorbate showed no activity in either test system. When freshly prepared sodium sorbate solutions were used, no genotoxic or cell-transforming activity was detected. However, sodium sorbate as stored solution, which previously had been heated and sonicated to facilitate solubilization, yielded a positive response in both test systems. It is concluded that oxidation products of sodium sorbate that possess genotoxic and cell-transforming properties are formed under conditions of heating, sonication and storage.

High colonic pH promotes colorectal cancer.

Considerable evidence suggests that the carcinogens or co-carcinogens responsible for the development of colorectal cancer are either bacterially degraded bile acids or cholesterol. It is proposed that a high colonic pH promotes co-carcinogen formation from these substances and that acidification of the colon either by dietary fibre (following its bacterial digestion to short-chain fatty acids) or milk (in lactose-intolerant individuals) may prevent this process.

Phospholipids in rice: significance in grain quality and health benefits: a review.

Phospholipids (PLs) are a major class of lipid in rice grain. Although PLs are only a minor nutrient compared to starch and protein, they may have both nutritional and functional significance. We have systemically reviewed the literature on the class, distribution and variation of PLs in rice, their relation to rice end-use quality and human health, as well as available methods for analytical profiling. Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI) and their lyso forms are the major PLs in rice. The deterioration of PC in rice bran during storage was considered as a trigger for the degradation of rice lipids with associated rancid flavour in paddy and brown rice. The lyso forms in rice endosperm represent the major starch lipid, and may form inclusion complexes with amylose, affecting the physicochemical properties and digestibility of starch, and hence its cooking and eating quality. Dietary PLs have a positive impact on several human diseases and reduce the side-effects of some drugs. As rice has long been consumed as a staple food in many Asian countries, rice PLs may have significant health benefits for those populations. Rice PLs may be influenced both by genetic (G) and environmental (E) factors, and resolving G×E interactions may allow future exploitation of PL composition and content, thus boosting rice eating quality and health benefits for consumers. We have identified and summarised the different methods used for rice PL analysis, and discussed the consequences of variation in reported PL values due to inconsistencies between methods. This review enhances the understanding of the nature and importance of PLs in rice and outlines potential approaches for manipulating PLs to improve the quality of rice grain and other cereals. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health?

This review looks at the role of an alkaline diet in health. Pubmed was searched looking for articles on pH, potential renal acid loads, bone health, muscle, growth hormone, back pain, vitamin D and chemotherapy. Many books written in the lay literature on the alkaline diet were also reviewed and evaluated in light of the published medical literature. There may be some value in considering an alkaline diet in reducing morbidity and mortality from chronic diseases and further studies are warranted in this area of medicine.

Evaluation of phenolic compounds in commercial fruit juices and fruit drinks.

The total phenolic content of 13 commercially available fruit juices and juice drinks, selected to represent the most popular juice flavors in the United Kingdom, were analyzed using the Folin-Ciocalteu assay. Individual phenolic compounds were identified and quantified using HPLC-PDA-MS2. The catechin content and degree of polymerization of proanthocyanidins were also analyzed. Purple grape juice contained the largest number of individual phenolic compounds and also the highest concentration of total phenolics. The main components were flavan-3-ols, anthocyanins, and hydroxycinnamates, which accounted for 93% of the total phenolic content. In contrast, white grape juice, which contained principally hydroxycinnamates, had the lowest total phenolic content. Antioxidant activity was measured using the ORAC and FRAP assays, and the data obtained were in broad agreement with total phenol content. In view of the recent findings of the Kame project indicating that long-term fruit juice consumption can provide protection against Alzheimer's disease (Dai et al. Am. J. Med. 2006, 379, 464-475), it is suggested that the protective effects may be enhanced by consumption of a combination of juices rich in phenolics and containing a diverse variety of individual phenolic compounds, namely, juices derived from purple grapes, grapefruit, cranberries, and apples.

Faecal pH value and its modification by dietary means in South African black and white schoolchildren.

Mean faecal pH values did not differ significantly in groups of rural South African Black schoolchildren of 10--12 years who ate their traditional high-fibre low-fat diet, and urban dwellers who consumed a partially westernized diet. However, both means were significantly lower than those of groups of White schoolchildren. In feeding studies of 5 days' duration, mean faecal pH value of Black children became significantly less acid when white bread replaced maize meal, and became significantly more acid when a supplement of 6 oranges was consumed daily. Supplements which consisted of skim milk, butter, and sugar had no significant effect on mean faecal pH value. In White children in an institution, the mean pH value of faeces became significantly more acid when a supplement of 6 oranges, although not of bran 'crunchies', was consumed daily.

Antitumour effects of Phyllanthus emblica L.: induction of cancer cell apoptosis and inhibition of in vivo tumour promotion and in vitro invasion o...

Phyllanthus emblica Linn. (PE) is a medicinal fruit used in many Asian traditional medicine systems for the treatment of various diseases including cancer. The present study tested the potential anticancer effects of aqueous extract of PE in four ways: (1) against cancer cell lines, (2) in vitro apoptosis, (3) mouse skin tumourigenesis and (4) in vitro invasiveness. The PE extract at 50-100 microg/mL significantly inhibited cell growth of six human cancer cell lines, A549 (lung), HepG2 (liver), HeLa (cervical), MDA-MB-231 (breast), SK-OV3 (ovarian) and SW620 (colorectal). However, the extract was not toxic against MRC5 (normal lung fibroblast). Apoptosis in HeLa cells was also observed as PE extract caused DNA fragmentation and increased activity of caspase-3/7 and caspase-8, but not caspase-9, and up-regulation of the Fas protein indicating a death receptor-mediated mechanism of apoptosis. Treatment of PE extract on mouse skin resulted in over 50% reduction of tumour numbers and volumes in animals treated with DMBA/TPA. Lastly, 25 and 50 microg/mL of PE extract inhibited invasiveness of MDA-MB-231 cells in the in vitro Matrigel invasion assay. These results suggest P. emblica exhibits anticancer activity against selected cancer cells, and warrants further study as a possible chemopreventive and antiinvasive agent. Copyright 2010 John Wiley & Sons, Ltd.

Bacteriophage biocontrol in animals and meat products

Summary Since their discovery almost a century ago, bacterial viruses (bacteriophages or ‘phages’) have been used to prevent and treat a multitude of bacterial infections (phage therapy: PT). In addition, they have been the basis for many advances in genetics and biochemistry. Phage therapy was performed on human subjects in the United States, Europe and Asia in the few decades following their discovery. However, Western countries largely abandoned PT in favour of antibiotics in the 1940s. The relatively recent renaissance of PT in the West can be attributed partly to the increasing prevalence of antibiotic resistance in human and animal pathogens. However, the stringent controls on human trials now required in the United States and Europe have led to a greater number of domestic animal and agricultural applications as an alternative to PT in man. This trend is set to continue, at least in the short term, with recent approval from the Food and Drug Administration allowing commercial phage treatments to be used in human food in the USA. Nevertheless, despite these significant milestones and the growing number of successful PT trials, significant obstacles remain to their widespread use in animals, food and ultimately medicine in many parts of the world. This review will provide a brief overview of the history of PT in the West and will summarize some of the key findings of phage biocontrol studies in animals and meat products.

Overview of antibacterial, antitoxin, antiviral, and antifungal activities of tea flavonoids and teas.

Tea leaves produce organic compounds that may be involved in the defense of the plants against invading pathogens including insects, bacteria, fungi, and viruses. These metabolites include polyphenolic compounds, the six so-called catechins, and the methyl-xanthine alkaloids caffeine, theobromine, and theophylline. Postharvest inactivation of phenol oxidases in green tea leaves prevents oxidation of the catechins, whereas postharvest enzyme-catalyzed oxidation (fermentation) of catechins in tea leaves results in the formation of four theaflavins as well as polymeric thearubigins. These substances impart the black color to black teas. Black and partly fermented oolong teas contain both classes of phenolic compounds. A need exists to develop a better understanding of the roles of polyphenolic tea compounds in food and medical microbiology. This overview surveys and interprets our present knowledge of activities of tea flavonoids and teas against foodborne and other pathogenic bacteria, virulent protein toxins produced by some of the bacteria, virulent bacteriophages, pathogenic viruses and fungi. Also covered are synergistic, mechanistic, and bioavailability aspects of the antimicrobial effects. Further research is suggested for each of these categories. The herein described findings are not only of fundamental interest, but also have practical implications for nutrition, food safety, and animal and human health.

L-theanine intervention enhances human gammadeltaT lymphocyte function.

Human gammadeltaT lymphocytes are a subset of T cells and are a first line of defense against microbes and tumors. These gammadeltaT cells can be primed by nitrogen-containing bisphosphonates, and certain short-chain alkylamines. These primed gammadeltaT cells have an enhanced capacity to proliferate and to secrete cytokines upon ex vivo exposure to a wide variety of microbes and tumor cells. The largest dietary source of alkylamines is L-theanine, an amino acid unique to tea beverages that is catabolized to ethylamine. Supplementation of subjects with capsules containing L-theanine and catechins has recently been shown to decrease the incidence of cold and flu symptoms, while enhancing gammadeltaT cell function.

Bioequivalence of Docosahexaenoic acid from different algal oils in capsules and in a DHA-fortified food.

Docosahexaenoic acid (DHA), a long-chain omega-3 fatty acid, is important for eye and brain development and ongoing visual, cognitive, and cardiovascular health. Unlike fish-sourced oils, the bioavailability of DHA from vegetarian-sourced (algal) oils has not been formally assessed. We assessed bioequivalence of DHA oils in capsules from two different algal strains versus bioavailability from an algal-DHA-fortified food. Our 28-day randomized, placebo-controlled, parallel group study compared bioavailability of (a) two different algal DHA oils in capsules ("DHASCO-T" and "DHASCO-S") at doses of 200, 600, and 1,000 mg DHA per day (n = 12 per group) and of (b) an algal-DHA-fortified food (n = 12). Bioequivalence was based on changes in plasma phospholipid and erythrocyte DHA levels. Effects on arachidonic acid (ARA), docosapentaenoic acid-n-6 (DPAn-6), and eicosapentaenoic acid (EPA) were also determined. Both DHASCO-T and DHASCO-S capsules produced equivalent DHA levels in plasma phospholipids and erythrocytes. DHA response was dose-dependent and linear over the dose range, plasma phospholipid DHA increased by 1.17, 2.28 and 3.03 g per 100 g fatty acid at 200, 600, and 1,000 mg dose, respectively. Snack bars fortified with DHASCO-S oil also delivered equivalent amounts of DHA on a DHA dose basis. Adverse event monitoring revealed an excellent safety and tolerability profile. Two different algal oil capsule supplements and an algal oil-fortified food represent bioequivalent and safe sources of DHA.

Inhibitory effect of tea polyphenols on local tissue damage induced by snake venoms.

The methanolic extract of fresh tea leaves of Camellia sinensis L. (Theaceae) (CS) was assayed for its potential to inhibit enzymes with hydrolytic activity in Naja naja kaouthia Lesson (Elapidae) and Calloselasma rhodostoma Kuhl (Viperidae) venoms. These snake venom enzymes are responsible for the early effects of envenomation, such as local tissue damage and inflammation. The CS extract inhibited phospholipase A(2), proteases, hyaluronidase and L-amino acid oxidase in both venoms by in vitro neutralization and inhibited the hemorrhagic and the dermonecrotic activities of the venoms in vivo. It is suggested that the inhibitory potential of the CS extract against local tissue damage induced by snake venoms may be attributed to complexation and chelation between the venom proteins and the phenolic contents of the extract.

Behaviour of some organophosphorus and organochlorine pesticides in potatoes during soaking in different solutions.

The efficiencies of acidic solutions (radish, citric acid, ascorbic acid, acetic acid and hydrogen peroxide), neutral solutions (sodium chloride) and alkaline solution (sodium carbonate) as well as tap water in the elimination of organochlorine and organophosphorus pesticides from naturally contaminated potatoes were examined. The results indicated that acidic solutions were more effective than neutral and alkaline solutions in the elimination of the organochlorine compounds under investigation, Radish solutions eliminated pesticides completely, except o,p'-DDE (73.1% loss), followed by citric and ascorbic acid solutions. On the other hand, organophosphorus pesticides (pirimphos methyl, malathion and profenofos) were eliminated more by acidic, neutral and alkaline solutions than by organochlorines. The percentage of removal ranged from 98.5 to 100% for pirimphos methyl, 87.9 to 100% for malathion and 100% for profenofos.

Advanced glycation end products as biomarkers and gerontotoxins - A basis to explore methylglyoxal-lowering agents for Alzheimer's disease?

Alzheimer's disease (AD) is the most common dementing disorder of late life. Although there might be various different triggering events in the early stages of the disease, they seem to converge on a few characteristic final pathways in the late stages, characterized by inflammation and neurodegeneration. In this review, we put forward the hypothesis that advanced glycation end products (AGEs) and their precursors, including methylglyoxal, are both biomarkers and causative agents ("gerontotoxins") characteristic for this disorder. Accumulation of AGEs is a normal feature of aging, but is accelerated in AD, where AGEs can be detected in amyloid plaques and neurofibrillary tangles. AGE modification may explain many of the neuropathological and biochemical features of AD such as extensive protein cross-linking, inflammation, oxidative stress and neuronal cell death. We suggest that methylglyoxal is one of the major carbonyl species responsible for the formation of AGEs. We propose that one promising pharmacological approach to prevent the formation of AGEs would be to lower the methylglyoxal concentration. This can be achieved, for example, by decreasing the concentration of methylglyoxal precursors such as d-glyceraldehyde-3-phosphate by allowing a higher flux through the pentose phosphate pathway or by increasing methylglyoxal detoxification through the glyoxalase system. Alternatively, methylglyoxal could be scavenged by various types of carbonyl scavengers. Copyright © 2010 Elsevier Inc. All rights reserved.

Neuroprotective effect of the natural iron chelator, phytic acid in a cell culture model of Parkinson's disease.

Disrupted iron metabolism and excess iron accumulation has been reported in the brains of Parkinson's disease (PD) patients. Because excessive iron can induce oxidative stress subsequently causing degradation of nigral dopaminergic neurons in PD, we determined the protective effect of a naturally occurring iron chelator, phytic acid (IP6), on 1-methyl-4-phenylpyridinium (MPP(+))-induced cell death in immortalized rat mesencephalic/dopaminergic cells. Cell death was induced with MPP(+) in normal and iron-excess conditions and cytotoxicity was measured by thiazolyl blue tetrazolium bromide (MTT assay) and trypan blue staining. Apoptotic cell death was also measured with caspase-3 activity, DNA fragmentation, and Hoechst nuclear staining. Compared to MPP(+) treatment, IP6 (30 micromol/L) increased cell viability by 19% (P<0.05) and decreased cell death by 22% (P<0.05). A threefold increase in caspase-3 activity (P<0.001) and a twofold increase in DNA fragmentation (P<0.05) with MPP(+) treatment was decreased by 55% (P<0.01) and 52% (P<0.05), respectively with IP6. Cell survival was increased by 18% (P<0.05) and 42% (P<0.001) with 30 and 100 micromol/L of IP6, respectively in iron-excess conditions. A 40% and 52% (P<0.001) protection was observed in caspase-3 activity with 30 and 100 micromol/L IP6, respectively in iron-excess condition. Similarly, a 45% reduction (P<0.001) in DNA fragmentation was found with 100 micromol/L IP6. In addition, Hoechst nuclear staining results confirmed the protective effect of IP6 against apoptosis. Similar protection was also observed with the differentiated cells. Collectively, our results demonstrate a significant neuroprotective effect of phytate in a cell culture model of PD.

Antifungal mechanisms supporting boric acid therapy of Candida vaginitis.

BACKGROUND: Boric acid is a commonly cited treatment for recurrent and resistant yeast vaginitis, but data about the extent and mechanism of its antifungal activity are lacking. OBJECTIVES: The aim of this study was to use in vitro methods to understand the spectrum and mechanism of boric acid as a potential treatment for vaginal infection. METHODS: Yeast and bacterial isolates were tested by agar dilution to determine the intrinsic antimicrobial activity of boric acid. Established microbial physiology methods illuminated the mechanism of the action of boric acid against Candida albicans. RESULTS: C. albicans strains (including fluconazole-resistant strains) were inhibited at concentrations attainable intravaginally; as were bacteria. Broth dilution MICs were between 1563 and 6250 mg/L and boric acid proved fungistatic (also reflected by a decrease in CO(2) generation); prolonged culture at 50,000 mg/L was fungicidal. Several organic acids in yeast nitrogen broth yielded a lower pH than equimolar boric acid and sodium borate but were less inhibitory. Cold or anaerobic incubation protected yeast at high boric acid concentrations. Cells maintained integrity for 6 h in boric acid at 37 degrees C, but after 24 h modest intrusion of propidium iodide occurred; loss of plate count viability preceded uptake of vital stain. Growth at sub-MIC concentrations of boric acid decreased cellular ergosterol. The drug efflux pump CDR1 did not protect Candida as CDR1 expression was abrogated by boric acid. Boric acid interfered with the development of biofilm and hyphal transformation. CONCLUSIONS: Boric acid is fungistatic to fungicidal depending on concentration and temperature. Inhibition of oxidative metabolism appears to be a key antifungal mechanism, but inhibition of virulence probably contributes to therapeutic efficacy in vivo.

Docosahexaenoic acid from a cultured microalga inhibits cell growth and induces apoptosis by upregulating Bax/Bcl-2 ratio in human breast carcinoma...

Docosahexaenoic acid (DHA) is an omega-3 fatty acid that comprises 22 carbons and 6 alternative double bonds in its hydrocarbon chain (22:6omega3). Previous studies have shown that DHA from fish oil controls the growth and development of different cancers; however, safety issues have been raised repeatedly about contamination of toxins in fish oil that makes it no longer a clean and safe source of the fatty acid. We investigated the cell growth inhibition of DHA from the cultured microalga Crypthecodinium cohnii (algal DHA [aDHA]) in human breast carcinoma MCF-7 cells. aDHA exhibited growth inhibition on breast cancer cells dose-dependently by 16.0% to 59.0% of the control level after 72-h incubations with 40 to 160 microM of the fatty acid. DNA flow cytometry shows that aDHA induced sub-G(1) cells, or apoptotic cells, by 64.4% to 171.3% of the control levels after incubations with 80 mM of the fatty acid for 24, 48, and 72 h. Western blot studies further show that aDHA did not modulate the expression of proapoptotic Bax protein but induced the downregulation of anti-apoptotic Bcl-2 expression time-dependently, causing increases of Bax/Bcl-2 ratio by 303.4% and 386.5% after 48- and 72-h incubations respectively with the fatty acid. Results from this study suggest that DHA from the cultured microalga is also effective in controlling cancer cell growth and that downregulation of antiapoptotic Bcl-2 is an important step in the induced apoptosis.

Diet-induced metabolic acidosis.

The modern Western-type diet is deficient in fruits and vegetables and contains excessive animal products, generating the accumulation of non-metabolizable anions and a lifespan state of overlooked metabolic acidosis, whose magnitude increases progressively with aging due to the physiological decline in kidney function. In response to this state of diet-derived metabolic acidosis, the kidney implements compensating mechanisms aimed to restore the acid-base balance, such as the removal of the non-metabolizable anions, the conservation of citrate, and the enhancement of kidney ammoniagenesis and urinary excretion of ammonium ions. These adaptive processes lower the urine pH and induce an extensive change in urine composition, including hypocitraturia, hypercalciuria, and nitrogen and phosphate wasting. Low urine pH predisposes to uric acid stone formation. Hypocitraturia and hypercalciuria are risk factors for calcium stone disease. Even a very mild degree of metabolic acidosis induces skeletal muscle resistance to the insulin action and dietary acid load may be an important variable in predicting the metabolic abnormalities and the cardiovascular risk of the general population, the overweight and obese persons, and other patient populations including diabetes and chronic kidney failure. High dietary acid load is more likely to result in diabetes and systemic hypertension and may increase the cardiovascular risk. Results of recent observational studies confirm an association between insulin resistance and metabolic acidosis markers, including low serum bicarbonate, high serum anion gap, hypocitraturia, and low urine pH. Copyright © 2011 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Maternal and fetal exposure to pesticides associated to genetically modified foods in Eastern Townships of Quebec, Canada.

Pesticides associated to genetically modified foods (PAGMF), are engineered to tolerate herbicides such as glyphosate (GLYP) and gluphosinate (GLUF) or insecticides such as the bacterial toxin bacillus thuringiensis (Bt). The aim of this study was to evaluate the correlation between maternal and fetal exposure, and to determine exposure levels of GLYP and its metabolite aminomethyl phosphoric acid (AMPA), GLUF and its metabolite 3-methylphosphinicopropionic acid (3-MPPA) and Cry1Ab protein (a Bt toxin) in Eastern Townships of Quebec, Canada. Blood of thirty pregnant women (PW) and thirty-nine nonpregnant women (NPW) were studied. Serum GLYP and GLUF were detected in NPW and not detected in PW. Serum 3-MPPA and CryAb1 toxin were detected in PW, their fetuses and NPW. This is the first study to reveal the presence of circulating PAGMF in women with and without pregnancy, paving the way for a new field in reproductive toxicology including nutrition and utero-placental toxicities. Copyright © 2011 Elsevier Inc. All rights reserved.

High-performance liquid chromatographic analysis of secoisolariciresinol diglucoside and hydroxycinnamic acid glucosides in flaxseed by alkaline ex...

A HPLC method was developed for the analysis of secoisolariciresinol diglucoside (SDG) and hydroxycinnamic acid glucosides in milled defatted flaxseed flour. Direct extraction by 1 M NaOH for 1 h at 20 degrees C resulted in a higher yield than that obtained by hydrolysis of alcoholic extracts. An internal standard, o-coumaric acid, was used and the method was found to be easy, fast, and with good repeatability. On dry matter basis, different samples of flaxseeds varied considerably in their content of (+)-SDG (11.9-25.9 mg/g), (-)-SDG (2.2-5.0 mg/g), p-coumaric acid glucoside (1.2-8.5 mg/g), and ferulic acid glucoside (1.6-5.0 mg/g).

Inactivation of Tautomerase Activity of Macrophage Migration Inhibitory Factor by Sulforaphane: A Potential Biomarker for Anti-inflammatory Intervention

Background Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine with keto-enol tautomerase activity, rises rapidly in response to inflammation, and is elevated in many chronic diseases. Isothiocyanates, such as sulforaphane from broccoli, are very potent inactivators of MIF tautomerase activity. A simple rapid method for determining this activity in tissues and body fluids may therefore be valuable for assessing severity of inflammation and efficacy of intervention. Methods Existing spectrophotometric assays of MIF, based on conversion of methyl L-dopachrome to methyl 5,6-dihydroxyindole-2-carboxylate and associated loss of absorption at 475 nm, lack sensitivity. Assay sensitivity and efficiency were markedly improved by reducing the nonenzymatic rate, by lowering pH to 6.2, replacing phosphate (which catalyzes the reaction) with Bis-Tris buffer, and converting to a microtiter plate format. Results A structure-potency study of MIF tautomerase inactivation by isothiocyanates showed that sulforaphane, benzyl, n-hexyl, and phenethyl isothiocyanates were especially potent. MIF tautomerase could be readily quantified in human urine concentrated by ultrafiltration. This activity comprised: (i) a heat-labile, sulforaphane-inactivated macromolecular fraction (presumably MIF) that was concentrated during ultrafiltration; (ii) a flow-through fraction, with constant activity during filtration, that was heat-stable, and insensitive to sulforaphane. Administration of the sulforaphane precursor glucoraphanin to human volunteers almost completely abolished urinary tautomerase activity, which was recovered over many hours. Conclusions A simple, rapid, quantitative MIF tautomerase assay has been developed as a potential biomarker for assessing inflammatory severity and effectiveness of intervention. Impact An improved assay for measuring MIF tautomerase activity and its applications are described.

Analysis of the erosive effect of different dietary substances and medications.

Excessive consumption of acidic drinks and foods contributes to tooth erosion. The aims of the present in vitro study were twofold: (1) to assess the erosive potential of different dietary substances and medications; (2) to determine the chemical properties with an impact on the erosive potential. We selected sixty agents: soft drinks, an energy drink, sports drinks, alcoholic drinks, juice, fruit, mineral water, yogurt, tea, coffee, salad dressing and medications. The erosive potential of the tested agents was quantified as the changes in surface hardness (ΔSH) of enamel specimens within the first 2 min (ΔSH2-0 = SH2 min - SHbaseline) and the second 2 min exposure (ΔSH4-2 = SH4 min - SH2 min). To characterise these agents, various chemical properties, e.g. pH, concentrations of Ca, Pi and F, titratable acidity to pH 7·0 and buffering capacity at the original pH value (β), as well as degree of saturation (pK - pI) with respect to hydroxyapatite (HAP) and fluorapatite (FAP), were determined. Erosive challenge caused a statistically significant reduction in SH for all agents except for coffee, some medications and alcoholic drinks, and non-flavoured mineral waters, teas and yogurts (P < 0·01). By multiple linear regression analysis, 52 % of the variation in ΔSH after 2 min and 61 % after 4 min immersion were explained by pH, β and concentrations of F and Ca (P < 0·05). pH was the variable with the highest impact in multiple regression and bivariate correlation analyses. Furthermore, a high bivariate correlation was also obtained between (pK - pI)HAP, (pK - pI)FAP and ΔSH.

Excess dietary protein can adversely affect bone.

The average American diet, which is high in protein and low in fruits and vegetables, generates a large amount of acid, mainly as sulfates and phosphates. The kidneys respond to this dietary acid challenge with net acid excretion, as well as ammonium and titratable acid excretion. Concurrently, the skeleton supplies buffer by active resorption of bone. Indeed, calciuria is directly related to net acid excretion. Different food proteins differ greatly in their potential acid load, and therefore in their acidogenic effect. A diet high in acid-ash proteins causes excessive calcium loss because of its acidogenic content. The addition of exogenous buffers, as chemical salts or as fruits and vegetables, to a high protein diet results in a less acid urine, a reduction in net acid excretion, reduced ammonium and titratable acid excretion, and decreased calciuria. Bone resorption may be halted, and bone accretion may actually occur. Alkali buffers, whether chemical salts or dietary fruits and vegetables high in potassium, reverse acid-induced obligatory urinary calcium loss. We conclude that excessive dietary protein from foods with high potential renal acid load adversely affects bone, unless buffered by the consumption of alkali-rich foods or supplements.

In vitro and in vivo efficacy of sulfo-carrabiose, a sugar-based cosmetic ingredient with anti-cellulite properties.

Most of adult women exhibit cellulite on the hips, buttock and thighs. Although extracellular matrix and lymphatic system disorders can increase its appearance, cellulite basically results from an excessive fat storage in the adipose tissue which exerts considerable pressure on the surrounding skin tissue and creates a dimpled irregular appearance. Caffeine, the most widely used anti-cellulite ingredient, favours fat break-down by inhibiting the phosphodiesterase enzyme and encouraging a high intracellular level of cAMP. A series of studies has shown that spermine and spermidine, two ubiquitous polyamines, encouraged fat storage and slowed fat break-down in the adipose tissue. Besides, it was shown that heparan sulfate glycosaminoglycans had a strong affinity for polyamines. To design a new cosmetic ingredient with anti-cellulite properties, we used molecular modelling to screen several ingredients with a structure similar to that of heparan sulfate glycosaminoglycans. This way, we identified sulfo-carrabiose as a potent molecule for trapping spermine and spermidine. These virtual results were first confirmed in tubo where sulfo-carrabiose was shown to dose-dependently inactivate spermine and spermidine. In vitro, adipocytes cultured with sulfo-carrabiose exhibited a significant reduction of lipogenesis and a significant increase of lipolysis. When sulfo-carrabiose was incorporated in a cosmetic formula, significant improvements were observed in thigh circumference, with better results than those obtained with caffeine after 28 days of use. Furthermore, a combination of caffeine and sulfo-carrabiose led to results significantly better than those obtained with caffeine alone. As measured by fringe projection, thigh volume was also significantly reduced after sulfo-carrabiose treatment. Finally, the appearance of cellulite assessed by clinical evaluation was also significantly reduced within 28 days. © 2010 BASF Beauty Care Solutions. ICS © 2010 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Uric acid: A marker of increased cardiovascular risk.

The relationship between uric acid and cardiovascular disease has been known since the 19th century, after that many authors reported the classical association of gout, hypertension, obesity and cardiovascular disease. With the exception of specific genetic defects in purine metabolism, increased uric acid is generally associated with important risk factors for atherosclerosis like hypertension, abdominal obesity, insulin resistance, the metabolic syndrome and renal failure. Studies have clearly shown an association between increased uric acid concentrations with oxidative stress, endothelial dysfunction, inflammation, subclinical atherosclerosis and an increased risk of cardiovascular events. Increased uric acid levels are independent markers of cardiovascular disease risk. Prospective studies are necessary to show that reduction of uric acid levels prevent cardiovascular events.

Sweet and sour cherry phenolics and their protective effects on neuronal cells.

The identification of phenolics from various cultivars of fresh sweet and sour cherries and their protective effects on neuronal cells were comparatively evaluated in this study. Phenolics in cherries of four sweet and four sour cultivars were extracted and analyzed for total phenolics, total anthocyanins, and their antineurodegenerative activities. Total phenolics in sweet and sour cherries per 100 g ranged from 92.1 to 146.8 and from 146.1 to 312.4 mg gallic acid equivalents, respectively. Total anthocyanins of sweet and sour cherries ranged from 30.2 to 76.6 and from 49.1 to 109.2 mg cyanidin 3-glucoside equivalents, respectively. High-performance liquid chromatography (HPLC) analysis revealed that anthocyanins such as cyanidin and peonidin derivatives were prevalent phenolics. Hydroxycinnamic acids consisted of neochlorogenic acid, chlorogenic acid, and p-coumaric acid derivatives. Glycosides of quercetin, kaempferol, and isorhamnetin were also found. Generally, sour cherries had higher concentrations of total phenolics than sweet cherries, due to a higher concentration of anthocyanins and hydroxycinnamic acids. A positive linear correlation (r2 = 0.985) was revealed between the total anthocyanins measured by summation of individual peaks from HPLC analysis and the total anthocyanins measured by the pH differential method, indicating that there was in a close agreement with two quantifying methods for measuring anthocyanin contents. Cherry phenolics protected neuronal cells (PC 12) from cell-damaging oxidative stress in a dose-dependent manner mainly due to anthocyanins. Overall results showed that cherries are rich in phenolics, especially in anthocyanins, with a strong antineurodegenerative activity and that they can serve as a good source of biofunctional phytochemicals in our diet.

Mutagenicity testing in the Salmonella typhimurium assay of phenolic compounds and phenolic fractions obtained from smokehouse smoke condensates.

Smokehouse smoke, which is used for flavouring meat products, was investigated for its mutagenic activity in the Salmonella typhimurium assay. We were chiefly concerned with the fractions free of polycyclic aromatic hydrocarbons but containing phenol compounds, which are responsible for the preservative and aromatizing properties of the smoke. The most abundantly occurring phenol compounds (phenol, cresols, 2,4-dimethylphenol, brenzcatechine, syringol, eugenol, vanilline and guaiacol) gave negative results when they were tested for mutagenicity at five concentrations up to 5000 micrograms/plate, with and without S-9 mix, using five strains of S. typhimurium. Even when phenol was further investigated in a variety of test conditions, no induction of his+ revertants was observed. When smokehouse smoke was condensed and fractionated the majority of the various phenolic fractions also gave negative results when tested at five concentrations using five strains of S. typhimurium. However there was a slight increase in the number of revertants in a few cases. The presence in the phenolic fractions of very small amounts of mutagenic impurities, the nature of which needs further investigation, cannot be excluded. These results support the further development of non-hazardous smoke-aroma preparations, based on the phenolic components of smokehouse smoke.

Effect of urine pH changed by dietary intervention on uric acid clearance mechanism of pH-dependent excretion of urinary uric acid

Background The finding reported in a previous paper - alkalization of urine facilitates uric acid excretion - is contradictory to what one might expect to occur: because food materials for the alkalization of urine contain fewer purine bodies than those for acidification, less uric acid in alkaline urine should have been excreted than in acid urine. To make clear what component of uric acid excretion mechanisms is responsible for this unexpected finding, we simultaneously collected data for the concentration of both creatinine and uric acid in serum as well as in urine, in order to calculate both uric acid and creatinine clearances. Methods Within the framework of the Japanese government’s health promotion program, we made recipes which consisted of protein-rich and less vegetable-fruit food materials for H + -load (acidic diet) and others composed of less protein and more vegetable-fruit rich food materials (alkaline diet). This is a crossover study within some limitations. Healthy female students, who had no medical problems at the regular physical examination provided by the university, were enrolled in this consecutive 5-day study for each test. From whole-day collected urine, total volume, pH, organic acid, creatinine, uric acid, titratable acid and all cations (Na+,K+,Ca2+,Mg2+,NH4+) and anions (Cl−,SO42−,PO4−) necessary for the estimation of acid–base balance were measured. In the early morning before breakfast of the 1st, 3rd and 5th experimental day, we sampled 5 mL of blood to estimate the creatinine and uric acid concentration in serum. Results and discussion Urine pH reached a steady state 3 days after switching from ordinary daily diets to specified regimens. The amount of acid generated ([SO42−] + organic acid − gut alkali)was linearly related with the excretion of acid (titratable acid + [NH4+] − [HCO3−]), indicating that H + in urine is generated by the metabolic degradation of food materials. Uric acid and excreted urine pH retained a linear relationship, as reported previously. Among the five factors which are associated with calculating clearances for both uric acid and creatinine, we identified a conspicuous difference between acidic and alkaline diets in the uric acid concentration in serum as well as in urine; uric acid in the serum was higher in the acidic group than in the alkaline group, while uric acid in the urine in the acidic group was lower than that in the alkaline group. These changes of uric acid in acidic urine and in serum were reflected in the reduction of its clearance. From these observations, it is considered that uric acid may be reabsorbed more actively in acidic urine than in alkaline urine. Conclusion We conclude that alkalization of urine by eating nutritionally well-designed alkaline -prone food is effective for removing uric acid from the body.

Faecal urobilinogen levels and pH of stools in population groups with different incidence of cancer of the colon, and their possible role in its aetiology.

Mean faecal urobilinogen levels and the pH of stools were both found to be higher in subjects from a population group at high risk of developing cancer of the colon than in subjects matched for age, sex and socioeconomic status from a low-risk population group. An alkaline reaction of the colon contents seems to have a tumorigenic effect by a direct action on the mucus of the mucous cells. An acidic reaction, on the other hand, appears to be protective. These differences are dependent on the patterns of diet and manner of eating. Proper mastication of food, roughage, cellulose and vegetable fibre, and short-chain fatty acids of milk and fermented milk products in the diet appear to be protective.

Phthalates exposure and attention-deficit/hyperactivity disorder in school-age children.

BACKGROUND: Very few studies have examined the association between attention-deficit/hyperactivity disorder (ADHD) and phthalate exposure in humans. The aim of this study was to investigate the impact of phthalates on symptoms of ADHD in school-age children. METHODS: A cross-sectional examination of urine phthalate concentrations was performed, and scores on measures of ADHD symptoms and neuropsychological dysfunction with regard to attention and impulsivity were obtained from 261 Korean children, age 8-11 years. RESULTS: Mono-2-ethylheyl phthalate (MEHP) and mono-2-ethyl-5-oxohexylphthalate (MEOP) for metabolites of Di-2-ethylhexylphthalate (DEHP) and mono-n-butyl phthalate (MNBP) for metabolites of dibutyl phthalate (DBP) were measured in urine samples. The mean concentrations of MEHP, MEOP, and MNBP were 34.0 microg/dL (SD = 36.3; range: 2.1-386.7), 23.4 microg/dL (SD = 23.0; range: .75-244.8), and 46.7 microg/L (SD = 21.4; range: 13.2-159.3), respectively. After adjustment for covariates, teacher-rated ADHD scores were significantly associated with DEHP metabolites but not with DBP metabolites. We also found significant relationships between the urine concentrations of metabolites for DBP and the number of omission and commission errors in continuous performance tests (CPT) after adjustment for covariates. CONCLUSION: The present study showed a strong positive association between phthalate metabolites in urine and symptoms of ADHD among school-age children.

Dietary citric acid enhances absorption of aluminum in antacids.

Ten healthy men ingested, twice daily between meals, during each of the seven-day experimental periods: (a) citric acid (as lemon juice), (b) Al(OH)3, or (c) Al(OH)3 + citric acid. Whole blood sampled after each dietary period was analyzed electrothermally after digestion with nitric acid. Moderate, but significant, increases in mean Al concentrations as compared with pretreatment values [5 (SD 3) micrograms of Al per liter] were seen after ingestion of either citric acid or Al(OH)3: 9 (SD 4) and 12 (SD 3) micrograms/L, respectively. Ingestion of both Al(OH)3 and citric acid resulted in a more pronounced, highly significant (p less than 0.001) increase in Al concentrations, to 23 (SD 2) micrograms Al/L, probably owing to formation and absorption of Al-citrate complexes.

Bile acids as carcinogens in human gastrointestinal cancers.

Bile acids were first proposed to be carcinogens in 1939 and 1940. On the basis of later work with rodent models, bile acids came to be regarded as cancer promoters rather than carcinogens. However, considerable indirect evidence, obtained more recently, supports the view that bile acids are carcinogens in humans. At least 15 reports, from 1980 through 2003, indicate that bile acids cause DNA damage. The mechanism is probably indirect, involving induction of oxidative stress and production of reactive oxygen species that then damage DNA. Repeated DNA damage likely increases the mutation rate, including the mutation rate of tumor suppressor genes and oncogenes. Additional reports, from 1994 through 2002, indicate that bile acids, at the increased concentrations accompanying a high fat diet, induce frequent apoptosis. Those cells within the exposed population with reduced apoptosis capability tend to survive and selectively proliferate. That bile acids cause DNA damage and may select for apoptosis-resistant cells (both leading to increased mutation), indicates that bile acids are likely carcinogens. In humans, an increased incidence of cancer of the laryngopharyngeal tract, esophagus, stomach, pancreas, the small intestine (near the Ampulla of Vater) and the colon are associated with high levels of bile acids. The much larger number of cell generations in the colonic (and, likely, other gastrointestinal) epithelia of humans compared to rodents may allow time for induction and selection of mutations leading to cancer in humans, although not in rodents.

Treatment of vulvovaginal candidiasis with boric acid powder.

A double-blind comparison was made of the use of 14 daily intravaginal gelatin capsules containing 600 mg of boric acid powder versus the use of identical capsules containing 100,000 U nystatin diluted to volume with cornstarch for the treatment of vulvovaginal candidiasis albicans. Cure rates for boric acid were 92% at 7 to 10 days after treatment and 72% at 30 days, whereas the nystatin cure rates were 64% at 7 to 10 days and 50% at 30 days. The speed of alleviation of signs and symptoms was similar for the two drugs. There were no untoward side effects, and cervical cytologic features were not affected. In vitro studies found boric acid to be fungistatic and its effectiveness to be unrelated to pH. Blood boron analyses indicated little absorption from the vagina and a half-life of less than 12 hours. Acceptance by the patients was better than for "messy" vaginal creams, and self-made capsules containing boric acid powder are inexpensive (31 cents for fourteen) compared with the costly medication commonly prescribed.

Biogenic amines in fish: roles in intoxication, spoilage, and nitrosamine formation--a review.

Biogenic amines are non-volatile amines formed by decarboxylation of amino acids. Although many biogenic amines have been found in fish, only histamine, cadaverine, and putrescine have been found to be significant in fish safety and quality determination. Despite a widely reported association between histamine and scombroid food poisoning, histamine alone appears to be insufficient to cause food toxicity. Putrescine and cadaverine have been suggested to potentiate histamine toxicity. With respect to spoilage on the other hand, only cadaverine has been found to be a useful index of the initial stage of fish decomposition. The relationship between biogenic amines, sensory evaluation, and trimethylamine during spoilage are influenced by bacterial composition and free amino acid content. A mesophilic bacterial count of log 6-7 cfu/g has been found to be associated with 5 mg histamine/100 g fish, the Food and Drug Administration (FDA) maximum allowable histamine level. In vitro studies have shown the involvement of cadaverine and putrescine in the formation of nitrosamines, nitrosopiperidine (NPIP), and nitrosopyrrolidine (NPYR), respectively. In addition, impure salt, high temperature, and low pH enhance nitrosamine formation, whereas pure sodium chloride inhibits their formation. Understanding the relationships between biogenic amines and their involvement in the formation of nitrosamines could explain the mechanism of scombroid poisoning and assure the safety of many fish products.

Domoic acid and human exposure risks: a review.

Domoic acid is a potent neurotoxin that is naturally produced by several diatom species of the genus Pseudo-nitzschia. The toxin acts as a glutamate agonist and is excitotoxic in the vertebrate central nervous system and other glutamate receptor-rich organs. Human exposure to domoic acid occurs via the consumption of contaminated shellfish that have accumulated the toxin while filter feeding on toxigenic phytoplankton during blooms. The first reported human domoic acid poisoning event occurred in Canada in 1987 during which clinical signs of acute toxicity such as gastrointestinal distress, confusion, disorientation, memory loss, coma and death were observed. The illness was named amnesic shellfish poisoning (ASP) and due to effective seafood monitoring programs there have been no documented ASP cases since 1987. However, domoic acid poisoning has a significant effect on marine wildlife and multiple poisoning events have occurred in marine birds and mammals over the last few decades. Currently, domoic acid producing diatom blooms are thought to be increasing in frequency world wide, posing an increasing threat to wildlife and human health. Of particular concern are the potential impacts of long-term low-level exposure in "at risk" human populations. The impacts of repetitive low-level domoic acid exposure are currently unknown. This review provides a basic description of the mechanism of action of domoic acid as well as a synthesis of information pertaining to domoic acid exposure routes, toxin susceptibility, and the importance of effective monitoring programs. The importance of investigating the potential human health impacts of long-term low-level domoic acid exposure in "at risk" human populations is also discussed. Published by Elsevier Ltd.

Polyphenols and phenolic acids from strawberry and apple decrease glucose uptake and transport by human intestinal Caco-2 cells.

The effect of polyphenols, phenolic acids and tannins (PPTs) from strawberry and apple on uptake and apical to basolateral transport of glucose was investigated using Caco-2 intestinal cell monolayers. Substantial inhibition on both uptake and transport was observed by extracts from both strawberry and apple. Using sodium-containing (glucose transporters SGLT1 and GLUT2 both active) and sodium-free (only GLUT2 active) conditions, we show that the inhibition of GLUT2 was greater than that of SGLT1. The extracts were analyzed and some of the constituent PPTs were also tested. Quercetin-3-O-rhamnoside (IC₅₀ =31 μM), phloridzin (IC₅₀=146 μM), and 5-caffeoylquinic acid (IC₅₀=2570 μM) contributed 26, 52 and 12%, respectively, to the inhibitory activity of the apple extract, whereas pelargonidin-3-O-glucoside (IC₅₀=802 μM) contributed 26% to the total inhibition by the strawberry extract. For the strawberry extract, the inhibition of transport was non-competitive based on kinetic analysis, whereas the inhibition of cellular uptake was a mixed-type inhibition, with changes in both V(max) and apparent K(m) . The results in this assay show that some PPTs inhibit glucose transport from the intestinal lumen into cells and also the GLUT2-facilitated exit on the basolateral side. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

MPTP: an industrial chemical and contaminant of illicit narcotics stimulates a new era in research on Parkinson's disease.

MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) causes selective destruction of dopaminergic neurons of the nigrostriatal pathway in humans and other primates. It is less specific and much less potent in mice and has only slight effects in rats. Differences in rates and sites of metabolism of MPTP to its active, toxic, highly polar metabolite, MPP+ (1-methyl-4-phenylpyridine), appear to influence species specificity. In rats, type B monoamine oxidase (MAO-B), which mediates the conversion of MPTP to MPP+, may act as an enzymatic barrier at brain microvessels, whereas in primates the enzyme, present mainly in astrocytes, appears important for bioactivation of MPTP into the toxic metabolite. MPP+ is a substrate for catecholamine uptake sites and is concentrated in these neurons. The molecular mechanism of MPP+ toxicity has not been established definitively, but conversion to a free radical or uptake by mitochondria and inhibition of mitochondrial respiratory enzymes, leading to calcium release and cell death have been suggested. The discovery of toxin which causes an animal model of Parkinson's disease has stimulated new research on environmental factors that might contribute to this progressive degenerative disorder and provides a means for assessing new approaches to therapy.

Effect of extracted housefly pupae peptide mixture on chilled pork preservation.

The peptide mixture from housefly pupae has broad spectrum antimicrobial activity but has not previously been reported as a food preservative. In this study, the preservation effects of a housefly pupae peptide mixture, nisin, and sodium dehydroacetate (DHA-S) on the number of mesophilic aerobic bacteria (MAB), total volatile basic nitrogen (TVB-N), and pH value of chilled pork were compared. All results showed that a good preservation effect was observed among 3 treatments with the peptide mixture of housefly pupae, nisin, and DHA-S and that there was no significant difference among them. These results indicate that housefly peptide mixture has a great potential as a food preservative. The results of scanning electron microscope and transmission electron microscopy suggest that the primary mechanism of housefly pupae peptide mixture may be bacterial cytoplasmic membrane lysis and pores induced in the membranes. Practical Applications: Peptide mixture extracted from housefly pupae using low-cost and simple method has broad spectrum antimicrobial activity. According to the effect on chilled pork preservation, extracted housefly peptide mixture has a great potential as a food preservative.

Propionate. Anti-obesity and satiety enhancing factor?

Propionate is produced along with acetate and butyrate as a result of fermentative activity of gut microflora on dietary fiber. It has long been known to exhibit hypophagic effects in ruminants, however, its potential physiological roles in non-ruminants as well as humans remained unnoticed over the years. In view of various studies pointing towards the hypophagic as well as hypocholesterolemic effects of propionate in humans, it may act as an important factor in amelioration of obesity, a lifestyle disease arising due to energy imbalance and growing at a startling rate globally. Short chain fatty acids have recently been ascribed as ligands to G-protein coupled receptors (GPRs) 41 and 43. Thus, propionate along with acetate may also be involved in the regulation of adipogenesis and adipokine release mediated via GPRs. The present review summarizes the evidence which collectively raise the possibility of propionate as a dietary factor to depress appetite and combat the obesity epidemic. Copyright © 2011 Elsevier Ltd. All rights reserved.

Diallyl sulfide inhibits PhIP-induced DNA strand breaks in normal human breast epithelial cells.

Heterocyclic amines (HCAs) are formed when meat products such as beef, chicken, pork and fish are cooked at high temperatures. The most abundant HCA found in the human diet is 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (PhIP). PhIP causes mammary carcinomas in female rats and mice, and is associated with an increased risk of developing colon, breast, and prostate cancer in humans. PhIP is metabolized by cytochrome P-450s producing N-OH-PhIP. The N-OH-PhIP can be esterified by phase II enzymes forming an arylnitrenium ion that binds to DNA causing adducts. Furthermore, N-OH-PhIP may be reduced by cytochrome b5 reductase producing superoxide anions and hydroxyl radicals causing DNA strand breaks. Diallyl sulfide (DAS) has been shown to prevent cancer in several animal models, presumably by metabolic modulation. We hypothesize that PhIP produces reactive oxygen species causing DNA strand breaks and that DAS will inhibit the formation of PhIP induced DNA strand breaks. To test this hypothesis we treated normal breast epithelial (MCF-10A) cells with PhIP, DAS and a combination of PhIP and DAS. The detection of lipid peroxides was used as a surrogate for ROS. Lipid peroxides were detected using a PeroxiDetect kit (Sigma). PhIP increased the production of lipid peroxides and DAS decreased the PhIP-induced peroxidation by 47%. To determine if PhIP causes DNA strand breaks in MCF-10A cells, cells were treated for 3, 6, 9, and 24 h with PhIP (100 microM), DAS (100 microM) and a combination of PhIP (100 microM) and DAS (100 microM). DNA strand breaks were evaluated using the Comet assay. PhIP produced DNA strand breaks in a dose- and time-dependent fashion. We have shown that DAS inhibits PhIP-induced DNA strand breaks by inhibiting the production of reactive oxygen species. Therefore, we propose that DAS can prevent PhIP-induced breast cancer.

Erosive potentials of brewed teas.

PURPOSE: To measure the pH, titratable acidity, fluoride concentration and erosive potential of brewed teas. METHODS: Bag teas were purchased to represent black, green, citrus, fruity, and floral tea flavors from Tulsi, Bigelow, HyVee, Tazo, and Yogi brands and brewed (1 bag/240 ml) in boiling water for 3 minutes. The pH, titratable acidity, and fluoride concentrations were measured. Following these measurements, a representative tea from each flavor was selected for investigation of erosion potential. Six extracted human molars were randomly assigned to each tea. Teeth were painted with fingernail polish to expose a 1 x 4 mm window and then soaked in tea for a total of 25 hours with teas refreshed every 5 hours. Teeth were then sectioned using a microtome and photographed using a polarized light microscope. Lesion depths (i.e., eroded surfaces) were measured using Image Pro Plus software. Differences in physiochemical properties and lesion depths between beverages were investigated using one-way ANOVA with post-hoc Tukey's HSD test. Relationships among lesion depths and physiochemical properties were evaluated using the Pearson correlation test. RESULTS: pH, titratable acidity and fluoride concentrations differed between tea flavors (P < 0.05) and between brands (P < 0.05). Lesion depths produced by the citrus tea (83.1 +/- 10.3 microm) were greater than those produced by the fruity tea (56.5 +/- 6.1 microm); both teas produced greater depths than black (30.1 +/- 7.4 microm), floral (25.0 +/- 3.2 microm) or green (22.3 +/- 6.3 microm) teas (P < 0.05). pH (r = -0.96; P = 0.009) was inversely and titratable acidity (r = 0.97; P = 0.006) was positively associated with lesion depths.

Identification of peptide hormones of the amphipathic helix class using the helical hydrophobic moment algorithm.

Eisenberg's helical hydrophobic moment (less than mu H greater than) algorithm was applied to the analysis of the primary structure of amphipathic alpha-helical peptide hormones and an optimal method for identifying other peptides of this class determined. We quantitate and compare known amphipathic helical peptide hormones with a second group of peptides with proven nonamphipathic properties and determine the best method of distinguishing between them. The respective means of the maximum 11 residue less than mu H greater than for the amphipathic helical and control peptides were 0.46 (+/-/-0.07) and 0.33 (0.07) (P + 0.004). To better reflect the amphipathic potential of the entire peptide, the percent of 11 residue segments in each peptide above a particular less than mu H greater than was plotted vs less than mu H greater than. The resulting curves are referred to as HM-C. The mean HM-C (of the two groups) was highly significantly different such that the HM-C method was superior to others in its ability to distinguish amphipathic from nonamphipathic peptides. Several potential new members of this structural class were identified using this approach. Molecular modeling of a portion of one of these, prolactin inhibitory factor, reveals a strongly amphipathic alpha helix at residues 4-21. This computer-based method may enable rapid identification of peptides of the amphipathic alpha-helix class.

Detection of PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine) in the milk of healthy women.

An increased risk of breast cancer has been observed in women who consume "very well-done" meats. Heterocyclic amines are mutagenic and carcinogenic pyrolysis products formed during high temperature cooking of meats. In the present study, human milk samples were analyzed for PhIP, one of the most abundant dietary heterocyclic amine. A protocol was developed with a mixed-mode cation exchange sorbent for the extraction of heterocyclic amines from milk. Milk samples were acquired from healthy Canadian women. With LC/MS analysis and the method of isotope dilution for quantification, levels of PhIP were determined in human milk samples. PhIP was detected in 9 of the 11 milk samples, at levels as high as 59 pg/mL (ppt). No PhIP was detected in the milk of the vegetarian donor. Detection of PhIP in milk indicates that ductal mammary epithelial cells are directly exposed to this carcinogen, suggesting that heterocyclic amines are possible human mammary carcinogens.

Protective effect of myo-inositol hexaphosphate (phytate) on bone mass loss in postmenopausal women.

INTRODUCTION: The objective of this paper was to evaluate the relationship between urinary concentrations of InsP6, bone mass loss and risk fracture in postmenopausal women. MATERIALS AND METHODS: A total of 157 postmenopausal women were included in the study: 70 had low (≤0.76 μM), 42 intermediate (0.76-1.42 μM) and 45 high (≥1.42 μM) urinary phytate concentrations. Densitometry values for neck were measured at enrollment and after 12 months (lumbar spine and femoral neck), and 10-year risk fracture was calculated using the tool FRAX(®). RESULTS: Individuals with low InsP6 levels had significantly greater bone mass loss in the lumbar spine (3.08 ± 0.65 % vs. 0.43 ± 0.55 %) than did those with high phytate levels. Moreover, a significantly greater percentage of women with low than with high InsP6 levels showed more than 2 % of bone mass loss in the lumbar spine (55.6 vs. 20.7 %). The 10-year fracture probability was also significantly higher in the low-phytate group compared to the high-phytate group, both in hip (0.37 ± 0.06 % vs 0.18 ± 0.04 %) and major osteoporotic fracture (2.45 ± 0.24 % vs 1.83 ± 0.11 %). DISCUSSION: It can be concluded that high urinary phytate concentrations are correlated with reduced bone mass loss in lumbar spine over 12 months and with reduced 10-year probability of hip and major osteoporotic fracture, indicating that increased phytate consumption can prevent development of osteoporosis.

Gastro-intestinal availability of aluminium from tea.

The in vitro speciation of aluminium (Al) in black tea infusion (pH 4.8) was assessed using 3000, 10,000 and 30,000 Da cut-off ultrafilters, and the effect of adding human gastric juice (pH 2.3) and then raising the pH to 6.5 were also studied. 78% Al in the tea infusion passed through the 3000-Da ultrafilter; this percentage increased to more than 90% with the addition of gastric juice at pH 2.3, but then reduced to approximately 5% when the incubate was adjusted to pH 6.5. The breakdown of tea-derived polyphenols to low molecular weight phenols in vivo was measured using high-resolution 1H nuclear magnetic resonance spectroscopic analysis of ileostomy effluent, but there was no evidence of low molecular weight breakdown products from the polyphenols of ingested tea in this effluent. These results suggest that only a small proportion of Al in tea is potentially available for absorption throughout the small bowel. It may be misleading to estimate systemic Al absorption from tea drinking simply from total urinary aluminium excretion as has been done previously.

Formation of a mutagenic heterocyclic aromatic amine from creatinine in urine of meat eaters and vegetarians.

Liquid chromatography electrospray ionization mass spectrometry (MS) with a triple quadrupole MS was used to identify known and novel heterocyclic aromatic amines (HAAs) in human urine. The identities of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (8-MeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) were confirmed by their product ion spectra. The constant neutral loss scan mode was employed to probe for other analytes in urine that display the transition [M+H]+-->[M+H-CH3*]+*, which is common to HAAs containing an N-methylimidazo moiety, and led to the detection of a previously unreported isomer of 8-MeIQx [Holland, R., et al. (2004) Chem. Res. Toxicol. 17, 1121-1136]. We now report the identification of another novel HAA, 2-amino-1-methylimidazo[4,5-b]quinoline (IQ[4,5-b]), an isomer of the powerful animal carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline (IQ). The amounts of IQ[4,5-b] measured in the urine of human volunteers who consumed grilled beef ranged from 15 to 135% of the ingested dose, while the amounts of 8-MeIQx and PhIP excreted in urine were on average <2% of the ingested dose. Base treatment of urine at 70 degrees C increased the concentrations of 8-MeIQx and PhIP by as much as 6-fold, indicating the presence of phase II conjugates; however, the amount of IQ[4,5-b] increased by more than 100-fold. IQ[4,5-b] was also detected in the urine of vegetarians following base hydrolysis. The formation of IQ[4,5-b], but not IQ, 8-MeIQx, or PhIP, also occurred in urine incubated at 37 degrees C. Creatinine and 2-aminobenzaldehyde are likely precursors of IQ[4,5-b]. The detection of IQ[4,5-b] in the urine of both meat eaters and vegetarians suggests that this HAA may be present in nonmeat staples or that IQ[4,5-b] formation may occur endogenously within the urinary bladder or other biological fluids.

Pharmacodynamic and pharmacokinetic study of oral Curcuma extract in patients with colorectal cancer.

Curcuma spp. extracts, particularly the dietary polyphenol curcumin, prevent colon cancer in rodents. In view of the sparse information on the pharmacodynamics and pharmacokinetics of curcumin in humans, a dose-escalation pilot study of a novel standardized Curcuma extract in proprietary capsule form was performed at doses between 440 and 2200 mg/day, containing 36-180 mg of curcumin. Fifteen patients with advanced colorectal cancer refractory to standard chemotherapies received Curcuma extract daily for up to 4 months. Activity of glutathione S-transferase and levels of a DNA adduct (M(1)G) formed by malondialdehyde, a product of lipid peroxidation and prostaglandin biosynthesis, were measured in patients' blood cells. Oral Curcuma extract was well tolerated, and dose-limiting toxicity was not observed. Neither curcumin nor its metabolites were detected in blood or urine, but curcumin was recovered from feces. Curcumin sulfate was identified in the feces of one patient. Ingestion of 440 mg of Curcuma extract for 29 days was accompanied by a 59% decrease in lymphocytic glutathione S-transferase activity. At higher dose levels, this effect was not observed. Leukocytic M(1)G levels were constant within each patient and unaffected by treatment. Radiologically stable disease was demonstrated in five patients for 2-4 months of treatment. The results suggest that (a) Curcuma extract can be administered safely to patients at doses of up to 2.2 g daily, equivalent to 180 mg of curcumin; (b) curcumin has low oral bioavailability in humans and may undergo intestinal metabolism; and (c) larger clinical trials of Curcuma extract are merited.

Dietary Intake Is Associated with Phthalate Body Burden in a Nationally Representative Sample

Background Phthalates are compounds that are used in a wide range of consumer products. However, the contribution of dietary intake to phthalate exposure has not been well defined. Objective The objective of this study was to assess the contribution of different food types to phthalate exposure. Phthalates are chemicals of concern because of the high levels measured in people and the environment, as well as the demonstrated toxicity in animal studies and limited epidemiological studies. Previous research, although limited, has suggested that phthalates contaminate food in various countries. Methods We conducted an exploratory analysis of data collected as part of the 2003–2004 National Health and Nutrition Examination Survey (NHANES). Associations between dietary intake (assessed by a 24-hr dietary recall) for a range of food types (meat, poultry, fish, fruit, vegetable, and dairy) and phthalate metabolites measured in urine were analyzed using multiple linear regression modeling. Results We found that metabolites of di-(2-ethylhexyl) phthalate (DEHP) and high-molecular-weight phthalate metabolites were associated with the consumption of poultry. Monoethyl phthalate, the metabolite of diethyl phthalate (DEP), was associated with vegetable consumption, specifically tomato and potato consumption. Discussion These results, combined with results from previous studies, suggest that diet is an important route of intake for phthalates. Further research is needed to determine the sources of food contamination with these toxic chemicals and to describe the levels of contamination of U.S. food in a large, representative U.S. sample.

Effect of cooking on garlic (Allium sativum L.) antiplatelet activity and thiosulfinates content.

The raw form of garlic and some of its preparations are widely recognized as antiplatelet agents that may contribute to the prevention of cardiovascular disease. Herein, we examined the in-vitro antiaggregatory activity (IVAA) of human blood platelets induced by extracts of garlic samples that were previously heated (in the form of crushed versus uncrushed cloves) using different cooking methods and intensities. The concentrations of allicin and pyruvate, two predictors of antiplatelet strength, were also monitored. Oven-heating at 200 degrees C or immersing in boiling water for 3 min or less did not affect the ability of garlic to inhibit platelet aggregation (as compared to raw garlic), whereas heating for 6 min completely suppressed IVAA in uncrushed, but not in previously crushed, samples. The latter samples had reduced, yet significant, antiplatelet activity. Prolonged incubation (more than 10 min) at these temperatures completely suppressed IVAA. Microwaved garlic had no effect on platelet aggregation. However, increasing the concentration of garlic juice in the aggregation reaction had a positive IVAA dose response in crushed, but not in uncrushed, microwaved samples. The addition of raw garlic juice to microwaved uncrushed garlic restored a full complement of antiplatelet activity that was completely lost without the garlic addition. Garlic-induced IVAA was always associated with allicin and pyruvate levels. Our results suggest that (1) allicin and thiosulfinates are responsible for the IVAA response, (2) crushing garlic before moderate cooking can reduce the loss of activity, and (3) the partial loss of antithrombotic effect in crushed-cooked garlic may be compensated by increasing the amount consumed.

Age and systemic acid-base equilibrium: analysis of published data.

To investigate whether systemic acid-base equilibrium changes with aging in normal adult humans, we reviewed published articles reporting the acid-base composition of arterial, arterialized venous, or capillary blood in age-identified healthy subjects. We extracted or calculated blood hydrogen ion concentration ([H+]), plasma bicarbonate concentration ([HCO3(-)]), blood PCO2, and age, and computed a total of 61 age-group means, distributed among eight 10-year intervals from age 20 to 100 years. Using linear regression analysis, we found that with increasing age, there is a significant increase in the steady-state blood [H+] (p < .001), and reduction in steady-state plasma [HCO3(-)] (p < .001), indicative of a progressively worsening low-level metabolic acidosis. Blood PCO2 decreased with age (p < .05), in keeping with the expected respiratory adaptation to metabolic acidosis. Such age-related increasing metabolic acidosis may reflect in part the normal decline of renal function with increasing age. The role of age-related metabolic acidosis in the pathogenesis of the degenerative diseases of aging warrants consideration.

Modern organic and broiler chickens sold for human consumption provide more energy from fat than protein.

OBJECTIVE: In 1976, the Royal College of Physicians and the British Cardiac Society recommended eating less fatty red meat and more poultry instead because it was lean. However, the situation has changed since that time, with a striking increase in fat content of the standard broiler chicken. The aim of the present study was to report a snapshot of data on fat in chickens now sold to the public. DESIGN: Samples were obtained randomly between 2004 and 2008 from UK supermarkets, farm shops and a football club. The amount of chicken fat was estimated by emulsification and chloroform/methanol extraction. SETTING: Food sold in supermarkets and farms in England. SUBJECTS: Chicken samples. RESULTS: The fat energy exceeded that of protein. There has been a loss of n-3 fatty acids. The n-6:n-3 ratio was found to be as high as 9:1, as opposed to the recommendation of about 2:1. Moreover, the TAG level in the meat and whole bird mostly exceeded the proportion of phospholipids, which should be the higher for muscle function. The n-3 fatty acid docosapentaenoic acid (DPA, 22 : 5n-3) was in excess of DHA (22 : 6n-3). Previous analyses had, as usual for birds, more DHA than DPA. CONCLUSIONS: Traditional poultry and eggs were one of the few land-based sources of long-chain n-3 fatty acids, especially DHA, which is synthesized from its parent precursor in the green food chain. In view of the obesity epidemic, chickens that provide several times the fat energy compared with protein seem illogical. This type of chicken husbandry needs to be reviewed with regard to its implications for animal welfare and human nutrition.

Vinegar supplementation lowers glucose and insulin responses and increases satiety after a bread meal in healthy subjects.

OBJECTIVE: To investigate the potential of acetic acid supplementation as a means of lowering the glycaemic index (GI) of a bread meal, and to evaluate the possible dose-response effect on postprandial glycaemia, insulinaemia and satiety. SUBJECTS AND SETTING: In all, 12 healthy volunteers participated and the tests were performed at Applied Nutrition and Food Chemistry, Lund University, Sweden. INTERVENTION: Three levels of vinegar (18, 23 and 28 mmol acetic acid) were served with a portion of white wheat bread containing 50 g available carbohydrates as breakfast in randomized order after an overnight fast. Bread served without vinegar was used as a reference meal. Blood samples were taken during 120 min for analysis of glucose and insulin. Satiety was measured with a subjective rating scale. RESULTS: A significant dose-response relation was seen at 30 min for blood glucose and serum insulin responses; the higher the acetic acid level, the lower the metabolic responses. Furthermore, the rating of satiety was directly related to the acetic acid level. Compared with the reference meal, the highest level of vinegar significantly lowered the blood glucose response at 30 and 45 min, the insulin response at 15 and 30 min as well as increased the satiety score at 30, 90 and 120 min postprandially. The low and intermediate levels of vinegar also lowered the 30 min glucose and the 15 min insulin responses significantly compared with the reference meal. When GI and II (insulinaemic indices) were calculated using the 90 min incremental area, a significant lowering was found for the highest amount of acetic acid, although the corresponding values calculated at 120 min did not differ from the reference meal. CONCLUSION: Supplementation of a meal based on white wheat bread with vinegar reduced postprandial responses of blood glucose and insulin, and increased the subjective rating of satiety. There was an inverse dose-response relation between the level of acetic acid and glucose and insulin responses and a linear dose-response relation between acetic acid and satiety rating. The results indicate an interesting potential of fermented and pickled products containing acetic acid.

Gastroenterology in ancient Egypt.

Physicians in ancient Egypt devoted their care to disorders of individual organs. Notable among the specialties was gastroenterology, a subject matter that occupied a major portion of the surviving medical papyri. Although they did not name diseases as we know them, Pharaonic physicians described a host of gastroenterological symptoms for which an extensive array of therapeutics was prescribed. Their clinical accounts indicated an impressive knowledge of gastric and anorectal conditions. In their thinking on disease mechanism, the circulating materia peccans absorbed from feces represented a major cause of medical symptoms and disorders. This served as the rationale for the popular practice of self-purgation with enemas.

Glucoraphanin and 4-hydroxyglucobrassicin contents in seeds of 59 cultivars of broccoli, raab, kohlrabi, radish, cauliflower, brussels sprouts, kal...

The importance of dietary sulforaphane in helping maintain good health continues to gain support within the health-care community and awareness among U.S. consumers. In addition to the traditional avenue for obtaining sulforaphane, namely, the consumption of appropriate cruciferous vegetables, other consumer products containing added glucoraphanin, the natural precursor to sulforaphane, are now appearing in the United States. Crucifer seeds are a likely source for obtaining glucoraphanin, owing to a higher concentration of glucoraphanin and the relative ease of processing seeds as compared to vegetative parts. Seeds of several commonly consumed crucifers were analyzed not only for glucoraphanin but also for components that might have negative health implications, such as certain indole-containing glucosinolates and erucic acid-containing lipids. Glucoraphanin, 4-hydroxyglucobrassicin, other glucosinolates, and lipid erucic acid were quantified in seeds of 33 commercially available cultivars of broccoli, 4 cultivars each of kohlrabi, radish, cauliflower, Brussels sprouts, kale, and cabbage, and 2 cultivars of raab.

Colloidal oatmeal: history, chemistry and clinical properties.

Oatmeal has been used for centuries as a soothing agent to relieve itch and irritation associated with various xerotic dermatoses. In 1945, a ready to use colloidal oatmeal, produced by finely grinding the oat and boiling it to extract the colloidal material, became available. Today, colloidal oatmeal is available in various dosage forms from powders for the bath to shampoos, shaving gels, and moisturizing creams. Currently, the use of colloidal oatmeal as a skin protectant is regulated by the U.S. Food and Drug Administration (FDA) according to the Over-The-Counter Final Monograph for Skin Protectant Drug Products issued in June 2003. Its preparation is also standardized by the United States Pharmacopeia. The many clinical properties of colloidal oatmeal derive from its chemical polymorphism. The high concentration in starches and beta-glucan is responsible for the protective and water-holding functions of oat. The presence of different types of phenols confers antioxidant and anti-inflammatory activity. Some of the oat phenols are also strong ultraviolet absorbers. The cleansing activity of oat is mostly due to saponins. Its many functional properties make colloidal oatmeal a cleanser, moisturizer, buffer, as well as a soothing and protective anti-inflammatory agent.

Monitoring of buccal epithelial cells by alkaline comet assay (single cell gel electrophoresis technique) in cytogenetic evaluation of chlorhexidine.

During the last few years, there has been increasing interest in buccal epithelial cells for cytogenetic evaluation of different materials. In the present study, the use of these cells and peripheral lymphocytes for cytogenetic evaluation of chlorhexidine digluconate (CHX) with comet assay (single cell gel electrophoresis, or SCGE) is reported. This technique detects DNA strand breaks in individual cells in alkaline conditions. Thirteen volunteers were requested to rinse their mouths with 0.12% CHX solution for 18 days. Buccal epithelial cells and peripheral blood lymphocytes were obtained from all participants at baseline and the end of the experimental period. One hundred cells per subject were analysed for the DNA damage. A statistical increase was observed in the damaged buccal and blood cells after the CHX application. The mean grade of damage in buccal cells was statistically different from that in blood cells. Due to minimal absorption of chlorhexidine into the tissues and low concentrations of free chlorhexidine in the oral cavity, the DNA damage produced by chlorhexidine in lymphocytes was lower than in buccal epithelial cells. As chlorhexidine does not accumulate in the body, the frequencies of DNA damage could be transient. Detected DNA damage after CHX use might be the indication of an earlier effect, before DNA repair begins, and could be reversible.

Direct and indirect cellular effects of aspartame on the brain.

The use of the artificial sweetener, aspartame, has long been contemplated and studied by various researchers, and people are concerned about its negative effects. Aspartame is composed of phenylalanine (50%), aspartic acid (40%) and methanol (10%). Phenylalanine plays an important role in neurotransmitter regulation, whereas aspartic acid is also thought to play a role as an excitatory neurotransmitter in the central nervous system. Glutamate, asparagines and glutamine are formed from their precursor, aspartic acid. Methanol, which forms 10% of the broken down product, is converted in the body to formate, which can either be excreted or can give rise to formaldehyde, diketopiperazine (a carcinogen) and a number of other highly toxic derivatives. Previously, it has been reported that consumption of aspartame could cause neurological and behavioural disturbances in sensitive individuals. Headaches, insomnia and seizures are also some of the neurological effects that have been encountered, and these may be accredited to changes in regional brain concentrations of catecholamines, which include norepinephrine, epinephrine and dopamine. The aim of this study was to discuss the direct and indirect cellular effects of aspartame on the brain, and we propose that excessive aspartame ingestion might be involved in the pathogenesis of certain mental disorders (DSM-IV-TR 2000) and also in compromised learning and emotional functioning.

Black rice anthocyanins inhibit cancer cells invasion via repressions of MMPs and u-PA expression.

Tumor metastasis is the most important cause of cancer death and various treatment strategies have targeted on preventing the occurrence of metastasis. Anthocyanins are natural colorants belonging to the flavonoid family, and are wildly used for their antioxidant properties. Here, we provided molecular evidence associated with the anti-metastatic effects of peonidin 3-glucoside and cyanidin 3-glucoside, major anthocyanins extracted from black rice (Oryza sativa L. indica), by showing a marked inhibition on the invasion and motility of SKHep-1 cells. This effect was associated with a reduced expression of matrix metalloproteinase (MMP)-9 and urokinase-type plasminogen activator (u-PA). Peonidin 3-glucoside and cyanidin 3-glucoside also exerted an inhibitory effect on the DNA binding activity and the nuclear translocation of AP-1. Furthermore, these compounds also exerted an inhibitory effect of cell invasion on various cancer cells (SCC-4, Huh-7, and HeLa). Finally, anthocyanins from O. sativa L. indica (OAs) were evidenced by its inhibition on the growth of SKHep-1 cells in vivo.

Chronic Parkinsonism in humans due to a product of meperidine-analog synthesis.

Four persons developed marked parkinsonism after using an illicit drug intravenously. Analysis of the substance injected by two of these patients revealed primarily 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP) with trace amounts of 1-methyl-4-phenyl-4-propionoxy-piperidine (MPPP). On the basis of the striking parkinsonian features observed in our patients, and additional pathological data from one previously reported case, it is proposed that this chemical selectively damages cells in the substantia nigra.

The stomach as a bioreactor: dietary lipid peroxidation in the gastric fluid and the effects of plant-derived antioxidants.

Atherosclerosis may result partly from processes that occur following food consumption and that involve oxidized lipids in chylomicrons. We investigated reactions that could occur in the acidic pH of the stomach and accelerate the generation of lipid hydroperoxides and co-oxidation of dietary constituents. The ability of dietary polyphenols to invert catalysis from pro-oxidation to antioxidation was examined. The acidic pH of gastric fluid amplified lipid peroxidation catalyzed by metmyoglobin or iron ions. Metmyoglobin catalyzed peroxidation of edible oil, resulting in 8-fold increase of hydroperoxide concentration. The incubation of heated muscle tissue in simulated gastric fluid for 2 h enhanced hydroperoxides accumulation by 6-fold to 1200 microM. In the presence of catechin or red wine polyphenols, metmyoglobin catalyzed the breakdown of hydroperoxides to zero, totally preventing lipid peroxidation and beta-carotene cooxidation. We suggest that human gastric fluid may be an excellent medium for enhancing the oxidation of lipids and other dietary constituents. The results indicate the potentially harmful effects of oxidized fats intake in the presence of endogenous catalysts found in foods, and the major benefit of including in the meal plant dietary antioxidants.

DHEA, DHEAS and PCOS.

Approximately 20-30% of PCOS women demonstrate excess adrenal precursor androgen (APA) production, primarily using DHEAS as a marker of APA in general and more specifically DHEA, synthesis. The role of APA excess in determining or causing PCOS is unclear, although observations in patients with inherited APA excess (e.g., patients with 21-hydroxylase deficient congenital classic or non-classic adrenal hyperplasia) demonstrate that APA excess can result in a PCOS-like phenotype. Inherited defects of the enzymes responsible for steroid biosynthesis, or defects in cortisol metabolism, account for only a very small fraction of women suffering from hyperandrogenism or APA excess. Rather, women with PCOS and APA excess appear to have a generalized exaggeration in adrenal steroidogenesis in response to ACTH stimulation, although they do not have an overt hypothalamic-pituitary-adrenal axis dysfunction. In general, extra-adrenal factors, including obesity, insulin and glucose levels, and ovarian secretions, play a limited role in the increased APA production observed in PCOS. Substantial heritabilities of APAs, particularly DHEAS, have been found in the general population and in women with PCOS; however, the handful of SNPs discovered to date account only for a small portion of the inheritance of these traits. Paradoxically, and as in men, elevated levels of DHEAS appear to be protective against cardiovascular risk in women, although the role of DHEAS in modulating this risk in women with PCOS remains unknown. In summary, the exact cause of APA excess in PCOS remains unclear, although it may reflect a generalized and inherited exaggeration in androgen biosynthesis of an inherited nature. Copyright © 2014 Elsevier Ltd. All rights reserved.

The effect of inositol hexaphosphate on the expression of selected metalloproteinases and their tissue inhibitors in IL-1β-stimulated colon cancer cells

Introduction Matrix metalloproteinases (MMPs) have repeatedly been shown to play a very active role in extracellular matrix degradation associated with tumor invasion and metastasis. Tissue inhibitors of MMPs (TIMPs) are well-known for their ability to inhibit MMP activity thereby inhibiting malignant progression. Inositol hexaphosphate (IP6 phytic acid) has been recognized to have both preventive and therapeutic effects against various cancers including that of colon. In in vitro studies, IP6 has been demonstrated to inhibit cancer cell adhesion and migration. In the present study, the effect of IP6 on the expression of MMP and TIMP genes was evaluated in unstimulated and IL-1β-stimulated colon cancer cell line Caco-2. Materials and methods Real-time QRT-PCR was used to validate the transcription level of selected MMP and TIMP genes in Caco-2 cells after treatment with 1 ng/ml of IL-1β, 2.5 mM of IP6, and both for 6, 12, and 24 h. Results Stimulation of cells with IL-1β only resulted in an overexpression of MMP and their TIMP mRNAs. A significant decrease in MMP-13, MMP-3, MMP-2, and TIMP-1 basal expression was achieved by IP6. IP6 was also an efficient downregulator of MMP-1, MMP-9, and TIMP-2 genes transcription stimulated by IL-1β in 6 h lasting culture. After 12 h, IL-1β-induced MMP-2 mRNA expression was significantly reduced by IP6. Conclusion Proinflammatory cytokine IL-1β upregulates MMP and TIMP mRNAs expression in colon cancer epithelial cells Caco-2. IP6 (2.5 mM) influences constitutive expression of both MMP and TIMP genes and downregulates IL-1β stimulated transcription of some of these genes. IP6 exerts its anti-metastatic activity through modulation of MMP and TIMP genes expression to prevent cancer cell migration and invasion.

Intestinal Microbial Metabolism of Phosphatidylcholine and Cardiovascular Risk

BACKGROUND Recent studies in animals have shown a mechanistic link between intestinal microbial metabolism of the choline moiety in dietary phosphatidylcholine (lecithin) and coronary artery disease through the production of a proatherosclerotic metabolite, trimethylamine-N-oxide (TMAO). We investigated the relationship among intestinal microbiota-dependent metabolism of dietary phosphatidylcholine, TMAO levels, and adverse cardiovascular events in humans. METHODS We quantified plasma and urinary levels of TMAO and plasma choline and betaine levels by means of liquid chromatography and online tandem mass spectrometry after a phosphatidylcholine challenge (ingestion of two hard-boiled eggs and deuterium [d9]-labeled phosphatidylcholine) in healthy participants before and after the suppression of intestinal microbiota with oral broad-spectrum antibiotics. We further examined the relationship between fasting plasma levels of TMAO and incident major adverse cardiovascular events (death, myocardial infarction, or stroke) during 3 years of follow-up in 4007 patients undergoing elective coronary angiography. RESULTS Time-dependent increases in levels of both TMAO and its d9 isotopologue, as well as other choline metabolites, were detected after the phosphatidylcholine challenge. Plasma levels of TMAO were markedly suppressed after the administration of antibiotics and then reappeared after withdrawal of antibiotics. Increased plasma levels of TMAO were associated with an increased risk of a major adverse cardiovascular event (hazard ratio for highest vs. lowest TMAO quartile, 2.54; 95% confidence interval, 1.96 to 3.28; P<0.001). An elevated TMAO level predicted an increased risk of major adverse cardiovascular events after adjustment for traditional risk factors (P<0.001), as well as in lower-risk subgroups. CONCLUSIONS The production of TMAO from dietary phosphatidylcholine is dependent on metabolism by the intestinal microbiota. Increased TMAO levels are associated with an increased risk of incident major adverse cardiovascular events. (Funded by the National Institutes of Health and others.)

Non-Specific Protein Modifications by a Phytochemical Induce Heat Shock Response for Self-Defense

Accumulated evidence shows that some phytochemicals provide beneficial effects for human health. Recently, a number of mechanistic studies have revealed that direct interactions between phytochemicals and functional proteins play significant roles in exhibiting their bioactivities. However, their binding selectivities to biological molecules are considered to be lower due to their small and simple structures. In this study, we found that zerumbone, a bioactive sesquiterpene, binds to numerous proteins with little selectivity. Similar to heat-denatured proteins, zerumbone-modified proteins were recognized by heat shock protein 90, a constitutive molecular chaperone, leading to heat shock factor 1-dependent heat shock protein induction in hepa1c1c7 mouse hepatoma cells. Furthermore, oral administration of this phytochemical up-regulated heat shock protein expressions in the livers of Sprague-Dawley rats. Interestingly, pretreatment with zerumbone conferred a thermoresistant phenotype to hepa1c1c7 cells as well as to the nematode Caenorhabditis elegans. It is also important to note that several phytochemicals with higher hydrophobicity or electrophilicity, including phenethyl isothiocyanate and curcumin, markedly induced heat shock proteins, whereas most of the tested nutrients did not. These results suggest that non-specific protein modifications by xenobiotic phytochemicals cause mild proteostress, thereby inducing heat shock response and leading to potentiation of protein quality control systems. We considered these bioactivities to be xenohormesis, an adaptation mechanism against xenobiotic chemical stresses. Heat shock response by phytochemicals may be a fundamental mechanism underlying their various bioactivities.

Avena sativa (Oat), a potential neutraceutical and therapeutic agent: an overview.

The aim of the present review article is to summarize the available information related to the availability, production, chemical composition, pharmacological activity, and traditional uses of Avena sativa to highlight its potential to contribute to human health. Oats are now cultivated worldwide and form an important dietary staple for the people in number of countries. Several varieties of oats are available. It is a rich source of protein, contains a number of important minerals, lipids, β-glucan, a mixed-linkage polysaccharide, which forms an important part of oat dietary fiber, and also contains various other phytoconstituents like avenanthramides, an indole alkaloid-gramine, flavonoids, flavonolignans, triterpenoid saponins, sterols, and tocols. Traditionally oats have been in use since long and are considered as stimulant, antispasmodic, antitumor, diuretic, and neurotonic. Oat possesses different pharmacological activities like antioxidant, anti-inflammatory, wound healing, immunomodulatory, antidiabetic, anticholesterolaemic, etc. A wide spectrum of biological activities indicates that oat is a potential therapeutic agent.

Antiproliferative effects of fresh and thermal processed green and red cultivars of curly kale (Brassica oleracea L. convar. acephala var. sabellica).

Brassica vegetables contain a diverse range of phytochemicals with biological properties such as antioxidant and anticancer activity. However, knowledge about how biological activities are affected by processing is lacking. A green cultivar and a red cultivar of curly kale were evaluated for water/methanol-soluble phytochemicals before and after processing involving blanching, freeze storage, and boil-in-bag heat treatment. In both kale cultivars, processing resulted in a significant decrease of total phenolics, antioxidant capacity, and content and distribution of flavonols, anthocyanins, hydroxycinnamic acids, glucosinolates, and vitamin C. Interestingly, the red curly kale cultivar had a higher capacity to withstand thermal loss of phytochemicals. The extracts of both green and red curly kale inhibited the cell proliferation of three human colon cancer cell lines (Caco-2, HT-29, and HCT 116). However, extracts from fresh plant material had a significantly stronger antiproliferative effect than extracts from processed plant material.

Blueberries and neuronal aging.

As the population of people in the United States over the age of 65 years continues to increase, so too will the incidence of age-related pathologies, including decreases in cognitive and motor function. In cases of severe deficits in memory or motor function, hospitalization and/or custodial care would be a likely outcome. This means that unless some way is found to reduce these age-related decrements in neuronal function, health care costs will continue to rise exponentially. Evidence is accumulating that consumption of blueberries may be one strategy to forestall or even reverse age-related neuronal deficits, as well as their subsequent behavioral manifestations, in order to increase healthy aging. Research suggests that the polyphenolic compounds found in blueberries exert their beneficial effects either through their ability to lower oxidative stress and inflammation or directly by altering the signaling involved in neuronal communication. These interventions, in turn, may protect against age-related deficits in cognitive and motor function. Appropriately, the US Department of Agriculture has figured prominently in these discoveries, through the efforts of two USDA researchers who worked for the department 100 years apart. Copyright © 2012 S. Karger AG, Basel.

Brain serotonin content: physiological regulation by plasma neutral amino acids.

When plasma tryptophan is elevated by the injection of tryptophan or insulin, or by the consumption of carbohydrates, brain tryptophan and serotonin also rise; however, when even larger elevations of plasma tryptophan are produced by the ingestion of protein-containing diets, brain tryptophan and serotonin do not change. The main determinant of brain tryptophan and serotonin concentrations does not appear to be plasma tryptophan alone, but the ratio of this amino acid to other plasma neutral amino acids (that is, tyrosine, phenylalanine, leucine, isoleucine, and valine) that compete with it for uptake into the brain.

HPLC analysis of serotonin, tryptamine, tyramine, and the hydroxycinnamic acid amides of serotonin and tyramine in food vegetables.

Biogenic monoamines such as serotonin, tryptamine, and tyramine function as neurotransmitters and mitogenic factors in animals and are involved in flowering, morphogenesis, and protection from and adaptation to environmental changes in plants. In plants, serotonin and tyramine are conjugated to form phenolic compounds via thioester linkages during the synthesis of hydroxycinnamic acid amides, including p-coumaroylserotonin (CS), feruloylserotonin (FS), p-coumaroyltyramine (CT), and feruloyltyramine (FT). In this study, we determined the amounts of the biogenic monoamines CS, FS, CT, and FT in commonly consumed vegetables using high-performance liquid chromatography. Serotonin, tryptamine, and tyramine were detected in all vegetables tested. The serotonin levels ranged from 1.8 to 294 microg/g of dry weight, the tryptamine levels ranged from 0.8 to 372 microg/g of dry weight, and the tyramine levels ranged from 1.4 to 286 microg/g of dry weight. The highest serotonin and tryptamine contents were found in tomato and cherry tomato (140.3-222 microg/g of dry weight), while paprika and green pepper had higher tyramine contents than the other vegetables (286 and 141.5 microg/g of dry weight, respectively). Overall, the levels of CS, FS, CT, and FT ranged from 0.03 to 13.8 microg/g of dry weight, with green onion possessing the highest levels of CS (0.69 microg/g of dry weight), FT (1.99 microg/g of dry weight), and CT (13.85 microg/g of dry weight).

Gut flora metabolism of phosphatidylcholine promotes cardiovascular disease

Metabolomics studies hold promise for discovery of pathways linked to disease processes. Cardiovascular disease (CVD) represents the leading cause of death and morbidity worldwide. A metabolomics approach was used to generate unbiased small molecule metabolic profiles in plasma that predict risk for CVD. Three metabolites of the dietary lipid phosphatidylcholine, namely choline, trimethylamine N-oxide (TMAO), and betaine, were identified and then shown to predict risk for CVD in an independent large clinical cohort. Dietary supplementation of mice with choline, TMAO or betaine promoted up-regulation of multiple macrophage scavenger receptors linked to atherosclerosis, and supplementation with choline or TMAO promoted atherosclerosis. Studies using germ-free mice confirmed a critical role for dietary choline and gut flora in TMAO production, augmented macrophage cholesterol accumulation and foam cell formation. Suppression of intestinal microflora in atherosclerosis-prone mice inhibited dietary choline-enhanced atherosclerosis. Genetic variations controlling expression of flavin monooxygenases (FMOs), an enzymatic source of TMAO, segregated with atherosclerosis in hyperlipidemic mice. Discovery of a relationship between gut flora-dependent metabolism of dietary phosphatidylcholine and CVD pathogenesis provides opportunities for development of both novel diagnostic tests and therapeutic approaches for atherosclerotic heart disease.

A case of fatal caffeine poisoning.

Caffeine is a natural alkaloid methylxanthine that is found in various plants such as coffee or tea. Symptoms of a severe overdose may present with hypokalemia, hyponatremia, ventricular arrhythmias, hypertension followed by hypotension, respiratory failure, seizures, rhabdomyolysis, ventricular fibrillation and finally circulatory collapse. A 21-year-old woman called for the ambulance herself soon after the ingestion of about 10,000 mg of caffeine. At the arrival of the ambulance, the patient went into cardiac arrest almost immediately. After a total resuscitation period of 34 min including seven counter-shocks and 2 mg epinephrine, the patient was stable enough to be transferred to the hospital. The patient soon went into VF again and received two more counter-shocks and 1 mg epinephrine and finally an intravenous bolus dose of 300 mg amiodarone. The initial arterial blood gas showed pH at 6.47, lactate at 33 mmol/l and potassium level at 2.3 mmol/l. Unfortunately, no blood samples for caffeine analysis were taken. Three days after hospital admission, the patient developed myoclonus, which did not respond to medical treatment. Excessive intake of caffeine may produce arrhythmias and pronounced hypokalemia and ensuing ventricular fibrillation. In case of counter-shock-resistant VF, it can be necessary to give an early loading dose of amiodarone. Furthermore, it may be beneficial to replace the potassium as early as possible. Epinephrine and buffer solutions used during resuscitation may further decrease blood potassium levels and should be administrated cautiously. Epinephrine can be replaced by other vasopressor drugs, such as vasopressin without effects on beta-receptors.

The cooked meat-derived mammary carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine promotes invasive behaviour of breast cancer cells.

The cooked meat derived genotoxic carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) induces cancer of the colon, prostate and mammary gland when fed to rats. Epidemiology studies link these tumours to a Western diet and exposure to heterocyclic amines such as PhIP. We have shown that PhIP is also potently estrogenic and have proposed that this hormonal activity contributes to its target site carcinogenicity. We now postulate that the estrogenic properties of PhIP influence metastatic potential. We have used an in vitro assay for cell invasion based upon digestion and migration through a reconstituted basement membrane model. Zymography and immunoblotting were used to confirm PhIP-mediated changes associated with induction of the invasive phenotype. Treatment of the mammary cancer cell lines MCF-7 and T47D with PhIP induces cells to digest and migrate through a reconstituted basement membrane. The response was dose dependent, observed at sub-nanomolar concentrations of PhIP and was inhibited by the antiestrogen ICI 182,780. The PhIP-induced invasive phenotype was associated with expression of cathepsin D, cyclooxygenase-2 and matrix metalloproteinase activity. These findings emphasise the range and potency of the biological activities associated with this cooked meat product and mechanistically support the tissue-specific carcinogenicity of the chemical. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Phosphate is a vascular toxin.

Elevated phosphate (P) levels are seen in advanced renal failure and, together with dysregulated calcium, parathyroid hormone and vitamin D levels, contribute to the complex of chronic kidney disease-mineral and bone disease (CKD-MBD). Converging evidence from in vitro, clinical and epidemiological studies suggest that increased P is associated with vascular calcification and mortality. When vessels are exposed to high P conditions in vitro, they develop apoptosis, convert to bone-like cells and develop extensive calcification. Clinical studies in children on dialysis show that high P is associated with increased vessel wall thickness, arterial stiffness and coronary calcification. Epidemiological studies in adult dialysis patients demonstrate a significant and independent association between raised P and mortality. Importantly, raised P is associated with cardiovascular changes even in pre-dialysis CKD, and also in subjects with normal renal function but high P. All P binders can effectively reduce serum P, and this decrease is linked to improved survival. Raised serum P triggers the release of fibroblast growth factor 23 (FGF-23), which has the beneficial effect of increasing P excretion in early CKD, but is increased several 1,000-fold in dialysis, and may be an independent cardiovascular risk factor. Both FGF-23 and its co-receptor Klotho may have direct effects on the vasculature leading to calcification. Fascinatingly, disturbances in FGF-23-Klotho and raised P have also been associated with premature aging. These data suggest that high P levels have adverse vascular effects and that maintaining the serum P levels in the normal range reduces cardiovascular risk and mortality.

Differential effect of oleic and palmitic acid on lipid accumulation and apoptosis in cultured hepatocytes.

BACKGROUND AND AIM: Studies have shown monounsaturated oleic acid to be less toxic than palmitic acid and to prevent/attenuate palmitic acid hepatocites toxicity in steatosis models in vitro. However, to what degree these effects are mediated by steatosis extent is unknown. METHODS: We evaluated whether steatosis per se is associated with hepatocytes apoptosis and determined the role of oleic and palmitic acid, the most abundant fatty acids in western diets, on triglyceride accumulation and apoptosis in an in vitro model of steatosis induced in three hepatocytic cell lines (HepG2, HuH7, WRL68). The impact of incubation for 24 h with oleic (0.66 and 1.32 mM) and palmitic acid (0.33 and 0.66 mM), alone or combined (molar ratio 2 : 1) on steatosis, apoptosis, and insulin signalling, was evaluated. RESULTS: Concurrent with PPARgamma and SREBP-1 gene activation, steatosis extent was larger when cells were treated with oleic than with palmitic acid; the latter fatty acid was associated with increased PPARalpha expression. Cell apoptosis was inversely proportional to steatosis deposition. Moreover, palmitic, but not oleic acid, impaired insulin signalling. Despite the higher amount of fat resulting from incubation of the two fatty acids combined, the apoptosis rate and impaired insulin signalling were lower than in cells treated with palmitic acid alone, indicating a protective effect of oleic acid. CONCLUSIONS: Oleic acid is more steatogenic but less apoptotic than palmitic acid in hepatocityc cell cultures. These data may provide a biological basis for clinical findings on dietary patterns and pathogenetic models of nonalcoholic fatty liver disease.

Effect of tomato industrial processing on phenolic profile and antiplatelet activity.

BACKGROUND: Regular consumption of fruits and vegetables (e.g., tomatoes) has been shown to be beneficial in terms of reducing the incidence of cardiovascular diseases. The industrial processing of tomatoes into tomato-based products includes several thermal treatments. Very little is known on the effect of tomato industrial processing on antiaggregatory activity and phenolic profile. METHODS: It was assessed the effect of tomato and by-products extracts on platelet aggregation induced by ADP, collagen, TRAP-6 and arachidonic acid. These in vitro antithrombotic properties were further supported in an in vivo model of thrombosis. A set of antiplatelet compounds has been selected for HPLC analysis in the different extracts. RESULTS: Some natural compounds such as chlorogenic, caffeic, ferulic and p-coumaric acids were identified by HPLC in tomatoes and its products may inhibit platelet activation. Red tomatoes, tomato products (sauce, ketchup and juice) and by-products extracts inhibited platelet aggregation induced adenosine 5'-diphosphate, collagen, thrombin receptor activator peptide-6 and arachidonic acid, but to a different extent. Also, pomace extract presents antithrombotic activity. CONCLUSIONS: Processed tomatoes may have a higher content of health-benefiting compounds than fresh ones. Pomace even presents the best antiplatelet activity. Finally, tomato products may be used as a functional ingredient adding antiplatelet activities to processed foods.

Phenolic substance characterization and chemical and cell-based antioxidant activities of 11 lentils grown in the northern United States.

Chemical and cellular antioxidant activities and phenolic profiles of 11 lentil cultivars grown in the cool northern parts of the United States were investigated. Individual phenolic compounds, including phenolic acids, flavan-3-ols, flavones, and anthocyanins, were further quantitatively investigated by HPLC. Cellular antioxidant activities (CAA) and peroxyl radical scavenging capacity (PRSC) were evaluated by fluorescence microplate reader. Cultivar Morton exhibited the highest individual flavan-3-ols (catechin and epicatechin) and total flavonoids, as well as the highest antioxidant properties (PRSC and CAA) among all lentils tested. Five phenolic acids of the benzoic types and their derivates (gallic, protocatechuic, 2,3,4-trihydroxybenzoic, p-hydroxybenzoic acid, and protocatechualdehyde) and four phenolic acids of the cinnamic type (chlorogenic, p-coumaric, m-coumaric, and sinapic acid) were detected in all lentil cultivars. Two flavan-3-ols [(+)-catechin and (-)-epicatechin] and one flavone (luteolin) were detected in all lentil cultivars. Among all phenolic compounds detected, sinapic acid was the predominant phenolic acid, and (+)-catechin and (-)-epicatechin were the predominant flavonoids. These results showed that different phenotype lentils possessed considerable variations in their individual phenolic compounds, as well as chemical and cellular antioxidant activities. Caffeic acid, catechin, epicatechin, and total flavonoids significantly (p < 0.05) correlated with peroxyl radical scavenging assay. Cellular antioxidant assay significantly correlated with chemical antioxidant assay ORAC. The results from this study could be very interesting for breeding programs to improve lentils for use as functional foods.

Antioxidant activity of blueberry fruit is impaired by association with milk.

The antioxidant properties of dietary phenolics are believed to be reduced in vivo because of their affinity for proteins. In this study we assessed the bioavailability of phenolics and the in vivo plasma antioxidant capacity after the consumption of blueberries (Vaccinium corymbosum L.) with and without milk. In a crossover design, 11 healthy human volunteers consumed either (a) 200 g of blueberries plus 200 ml of water or (b) 200 g of blueberries plus 200 ml of whole milk. Venous samples were collected at baseline and at 1, 2, and 5 h postconsumption. Ingestion of blueberries increased plasma levels of reducing and chain-breaking potential (+6.1%, p<0.001; +11.1%, p<0.05) and enhanced plasma concentrations of caffeic and ferulic acid. When blueberries and milk were ingested there was no increase in plasma antioxidant capacity. There was a reduction in the peak plasma concentrations of caffeic and ferulic acid (-49.7%, p<0.001, and -19.8%, p<0.05, respectively) as well as the overall absorption (AUC) of caffeic acid (p<0.001). The ingestion of blueberries in association with milk, thus, impairs the in vivo antioxidant properties of blueberries and reduces the absorption of caffeic acid.

Dark chocolate: an obesity paradox or a culprit for weight gain?

Obesity remains a major public health challenge, and its prevalence is dramatically increasing. Diet and exercise are typically recommended to prevent and manage obesity; however, the results are often conflicting. Polyphenols, a class of phytochemicals that have been shown to reduce the risk factors for diabetes type II and cardiovascular diseases, are recently suggested as complementary agents in the management of obesity through several mechanisms such as decreasing fat absorption and/or fat synthesis. Dark chocolate, a high source of polyphenols, and flavanols in particular, has lately received attention for its possible role in modulating obesity because of its potential effect on fat and carbohydrate metabolism, as well as on satiety. This outcome was investigated in animal models of obesity, cell cultures and few human observational and clinical studies. The research undertaken to date has shown promising results, with the possible implication of cocoa/dark chocolate in the modulation of obesity and body weight through several mechanisms including decreasing the expression of genes involved in fatty acid synthesis, reducing the digestion and absorption of fats and carbohydrates and increasing satiety. Copyright © 2013 John Wiley & Sons, Ltd.

Acrylamide in foods: a review of the science and future considerations.

Acrylamide occurs in foods commonly consumed in diets worldwide. It is formed from the reaction of reducing sugars (e.g., glucose or fructose) with the amino acid asparagine via the Maillard reaction, which occurs during heat processing of foods, primarily those derived from plant origin, such as potato and cereal products, above 120°C (248°F). The majority of epidemiological studies concerning potential relationships between acrylamide consumption and different types of cancer have indicated no increased risk, except with a few types that warrant further study. Efforts to reduce the formation of acrylamide in food products have resulted in some successes, but there is no common approach that works for all foods. Reduction in some foods is probably not possible. The results from a major toxicological study (aqueous intake of acrylamide by rats and mice) are in the process of being released. The status of current knowledge in these areas is reviewed.

Protein-source tryptophan as an efficacious treatment for social anxiety disorder: a pilot study.

Until recently, intact protein that is rich in tryptophan was not seen as an alternative to pharmaceutical-grade tryptophan because protein also contains large neutral amino acids (LNAAs) that compete for transport sites across the blood-brain barrier. Recent evidence indicates that when deoiled gourd seed (a rich source of tryptophan with approximately 22 mg/g protein) is combined with glucose (a carbohydrate that reduces serum levels of competing LNAAs) a clinical effect similar to that of pharmaceutical-grade tryptophan is achieved. Objective and subjective measures of anxiety in those suffering from social phobia (also known as social anxiety disorder) were employed to measure changes in anxiety in response to a stimulus as part of a double-blind, placebo-controlled, crossover study with a wash-out period of 1 week between study sessions. Subjects were randomly assigned to start with either (i) protein-source tryptophan (deoiled gourd seed) in combination with carbohydrate or (ii) carbohydrate alone. One week after the initial session, subjects returned for a follow-up session and received the opposite treatment of that received at the first session. All 7 subjects who began the study completed the 2-week protocol. Protein-source tryptophan with carbohydrate, but not carbohydrate alone, resulted in significant improvement on an objective measure of anxiety. Protein-source tryptophan combined with a high glycemic carbohydrate is a potential anxiolytic to those suffering from social phobia.

Antifungal agents vs. boric acid for treating chronic mycotic vulvovaginitis.

Ninety-two women with chronic mycotic vaginal infections were followed with microscopic examination of the vaginal discharge during prolonged therapy with antifungal agents and boric acid. A microscopic picture unique to chronic mycotic vaginitis was observed, representing the cytologic reaction of the mucous membrane to chronic yeast infection. This diagnostic tool proved extremely effective in detecting both symptomatic and residual, subclinical mycotic infection and provided a highly predictive measure of the probability of relapse. The ineffectiveness of conventional antifungal agents appeared to be the main reason for chronic mycotic infections. In contrast, boric acid was effective in curing 98% of the patients who had previously failed to respond to the most commonly used antifungal agents and was clearly indicated as the treatment of choice for prophylaxis.

Biomonitoring of Carcinogenic Heterocyclic Aromatic Amines in Hair: A Validation Study

A facile method was established to measure heterocyclic aromatic amines (HAAs) accumulated in human hair and rodent fur. The samples were digested by base hydrolysis, and the liberated HAAs were isolated by tandem solvent/solid-phase extraction. Quantification was done by liquid chromatography/tandem mass spectrometry, using a triple stage quadrupole mass spectrometer in the selected reaction monitoring mode. In a pilot study of 12 human volunteers, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was detected in hair of six meat-eaters at levels ranging from 290 to 890 pg/g hair. 2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-9H-pyrido[2,3-b]indole (AαC) were below the limit of quantification (LOQ) (50 pg/g hair) in hair from meat-eaters and six vegetarians. PhIP was detected in the hair from one vegetarian, and at level just above the LOQ (65 pg/g hair), indicating PhIP exposure occurs primarily through meat consumption. The levels of PhIP in hair samples from two meat-eaters varied by less than 24% over a 6-month interval, signifying that the exposure to PhIP and its accumulation in hair are relatively constant over time. In a controlled feeding study, female C57BL/6 mice were given these HAAs in their drinking water for 1 month, at six daily dose concentrations ranging from 0, 0.080 to 800 µg/kg body weight. PhIP was detected in fur of mice at all doses, whereas AαC and MeIQx were detected in fur at dosages ≥0.8 µg AαC/kg body weight and ≥8 µg MeIQx/kg body weight. There was a strong positive relationship between dosage and each of the HAAs accumulated in fur and their DNA adducts formed in liver and colon (p-values <0.0001); however, the levels of HAA in fur did not correlate to the levels of DNA adducts after adjustment of dose. Thus, hair appears to be a promising long-lived biomarker with by which we can assess the exposure to PhIP, a potential human carcinogen.

Comparative assessment of human exposure to phthalate esters from house dust in China and the United States.

Because of volatilization and leaching from their application in consumer and personal care products, phthalate esters are ubiquitous contaminants in the indoor environment. In this study, we measured concentrations and profiles of 9 phthalate esters in indoor dust samples collected from six cities in China (n = 75). For comparison, we also analyzed samples collected from Albany, New York, USA (n = 33). The results indicated that concentrations, except for dicyclohexyl phthalate (DCHP) and bis(2-ethylhexyl) phthalate (DEHP), and profiles of phthalate esters varied significantly between the two countries. Concentrations of diethyl phthalate (DEP), di-n-hexyl phthalate (DNHP), and benzyl butyl phthalate (BzBP) were 5 to 10 times higher in dust samples collected from Albany than those from the Chinese cities. In contrast, concentrations of di-iso-butyl phthalate (DIBP) in dust samples from Albany were 5 times lower than those from the Chinese cities. We estimated the daily intake (DI) of phthalate esters through the routes of dust ingestion and dermal dust absorption. The extent of contribution of indoor dust to human exposures varied, depending on the type of phthalate esters. The contribution of dust to DEHP exposure was 2-5% and 10-58% of the estimated total DIs in China and the USA, respectively. On the basis of the estimates of total DIs of phthalates, extrapolated from urinary metabolite concentrations, the contributions of inhalation, dermal absorption, and dietary intake to total DIs were estimated. The results indicated that dietary intake is the main source of exposure to DEHP (especially in China), whereas dermal exposure was a major source for DEP. This is the first study to elucidate sources of human exposure to phthalates among the general population in China.

Intervention of human breast cell carcinogenesis chronically induced by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine

More than 85% of breast cancers are sporadic and attributable to long-term exposure to environmental carcinogens, such as those in the diet, through a multistep disease process progressing from non-cancerous to premalignant and malignant stages. The chemical carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is one of the most abundant heterocyclic amines found in high-temperature cooked meats and is recognized as a mammary carcinogen. However, the PhIP’s mechanism of action in breast cell carcinogenesis is not clear. Here, we demonstrated, for the first time, that cumulative exposures to PhIP at physiologically achievable, pico to nanomolar concentrations effectively induced progressive carcinogenesis of human breast epithelial MCF10A cells from a non-cancerous stage to premalignant and malignant stages in a dose- and exposure-dependent manner. Progressive carcinogenesis was measured by increasingly- acquired cancer-associated properties of reduced dependence on growth factors, anchorage-independent growth, acinar-conformational disruption, proliferation, migration, invasion, tumorigenicity with metastasis and increased stem-like cell populations. These biological changes were accompanied by biochemical and molecular changes, including upregulated H-Ras gene expression, extracellular signal-regulated kinase (ERK) pathway activation, Nox-1 expression, reactive oxygen species (ROS) elevation, increased HIF-1α, Sp1, tumor necrosis factor-α, matrix metalloproteinase (MMP)-2, MMP-9, aldehyde dehydrogenase activity and reduced E-cadherin. The Ras-ERK-Nox-ROS pathway played an important role in not only initiation but also maintenance of cellular carcinogenesis induced by PhIP. Using biological, biochemical and molecular changes as targeted endpoints, we identified that the green tea catechin components epicatechin-3-gallate and epigallocatechin-3-gallate, at non-cytotoxic doses, were capable of suppressing PhIP-induced cellular carcinogenesis and tumorigenicity.

Effect of cooking and germination on phenolic composition and biological properties of dark beans (Phaseolus vulgaris L.).

Legumes are the basés diet in several countries. They hold a high nutritional value, but other properties related to human health are nowadays being studied. The aim of this work was to study the influence of processes (boiling or germination) on the phenolic composition of dark beans (Phaseolus vulgaris L. c.v. Tolosana) and their effect on their antioxidant, neuroprotective and anticancer ability. Phenolic composition of raw and processed dark beans was analysed by HPLC-PAD and HPLC-ESI/MS. The antioxidant activity was evaluated by ORAC. Astrocytes cultures (U-373) have been used to test their neuroprotective effect. Anticancer activities were evaluated on three different cell lines (renal adenocarcinoma (TK-10), breast adenocarcinoma (MCF-7) and melanoma (UACC-62)) by sulphorhodamine B method. Qualitative and quantitative differences in phenolic composition have been observed between raw and processed dark beans that influence the antioxidant activity, mainly for germinated samples which show a decrease of antioxidant capacity. Although every assayed extracts decreased reactive oxygen species release and exhibited cytotoxicity activities on cancer cell lines, raw beans proved to be the most active in neuroprotective and antitumoral effects; this sample is especially rich in phenolic compounds, mainly anthocyanins. This study further demonstrated that phenolic composition of dark beans is related with cooking process and so with their neuroprotective and anticancer activity; cooking of dark beans improves their digestion and absorption at intestinal level, while maintaining its protective ability on oxidative process at cellular level. Copyright © 2012 Elsevier Ltd. All rights reserved.

Carrageenans and their use in meat products.

Carrageenans are sulfated linear polysaccharides of D-galactose and 3,6-anhydro-D-galactose extracted from red seaweeds. They have been used by the food industry for their gelling, thickening, and stabilizing properties, and more recently by the meat industry for reduced fat products. Meat is a complex system of muscle tissue, connective tissue, fat, and water; during processing, numerous interactions occur among all these components. These interactions are responsible for the functional properties of the meat system. In meat products, carrageenans contribute to gel formation and water retention. Their addition is of special interest in low-fat meat products because fat reduction often leads to unacceptable, tough textures. When carrageenans are incorporated in these formulations, they improve the textural characteristics of the product by decreasing toughness and increasing juiciness. Although carrageenan interactions with milk proteins have been studied extensively, the mechanism by which carrageenans interact with meat proteins and the other meat components is not fully understood.

Low-pH cola beverages do not affect women's iron absorption from a vegetarian meal.

Preliminary data in the literature indicate that iron absorption from a meal may be increased when consumed with low-pH beverages such as cola, and it is also possible that sugar iron complexes may alter iron availability. A randomized, crossover trial was conducted to compare the bioavailability of nonheme iron from a vegetarian pizza meal when consumed with 3 different beverages (cola, diet cola, and mineral water). Sixteen women with serum ferritin concentrations of 11-54 µg/L were recruited and completed the study. The pizza meal contained native iron and added ferric chloride solution as a stable isotope extrinsic label; the total iron content of the meal was ~5.3 mg. Incorporation of iron from the meal into RBC was not affected by the type of drink (9.9% with cola, 9.4% with diet cola, and 9.6% with water). Serum ferritin and plasma hepcidin were correlated (r = 0.66; P<0.001) and both were significant predictors of iron bioavailability, but their combined effect explained only 30% of the inter-individual variation (P<0.001) and illustrates the current lack of understanding of mechanisms responsible for the fine-tuning of iron absorption. Although there was no effect of low-pH drinks on iron bioavailability in healthy women, their effect on absorption of fortification iron that requires solubilization in dilute acid, such as reduced iron, and in individuals with low gastric acid production, such as older people and individuals with Helicobacter pylori infection, warrants further investigation.

Assessment of antioxidant activity by using different in vitro methods.

In this study, six common tests for measuring antioxidant activity were evaluated by comparing four antioxidants and applying them to beverages (tea and juices): Trolox equivalent antioxidant capacity assay (TEAC I-III assay), Total radical-trapping antioxidant parameter assay (TRAP assay), 2,2-diphenyl-l-picrylhydrazyl assay (DPPH assay), N,N-dimethyl-p-phenylendiamine assay (DMPD assay), Photochemiluminescence assay (PCL assay) and Ferric reducing ability of plasma assay (FRAP assay). The antioxidants included gallic acid representing the group of polyphenols, uric acid as the main antioxidant in human plasma, ascorbic acid as a vitamin widely spread in fruits and Trolox as water soluble vitamin E analogue. The six methods presented can be divided into two groups depending on the oxidising reagent. Five methods use organic radical producers (TEAC I-III, TRAP, DPPH, DMPD, PCL) and one method works with metal ions for oxidation (FRAP). Another difference between these tests is the reaction procedure. Three assays use the delay in oxidation and determine the lag phase as parameter for the antioxidant activity (TEAC I, TRAP, PCL). They determine the delay of radical generation as well as the ability to scavenge the radical. In contrast, the assays TEAC II and III, DPPH, DMPD and FRAP analyse the ability to reduce the radical cation (TEAC II and III, DPPH, DMPD) or the ferric ion (FRAP). The three tests acting by radical reduction use preformed radicals and determine the decrease in absorbance while the FRAP assay measures the formed ferrous ions by increased absorbance. Gallic acid was the strongest antioxidant in all tests with exception of the DMPD assay. In contrast, uric acid and ascorbic acid showed low activity in some assays. Most of the assays determine the antioxidant activity in the micromolar range needing minutes to hours. Only one assay (PCL) is able to analyse the antioxidant activity in the nanomolar range. Black currant juice showed highest antioxidant activity in all tests compared to tea, apple juice and tomato juice. Despite these differences, results of these in vitro assays give an idea of the protective efficacy of secondary plant products. It is strongly recommended to use at least two methods due to the differences between the test systems investigated.

The significance of azo-reduction in the mutagenesis and carcinogenesis of azo dyes.

Azo dyes are widely used in textile, printing, cosmetic, drug and food-processing industries. They are also used extensively in laboratories as either biological stains or pH indicators. The extent of such use is related to the degree of industrialization. Since intestinal cancer is more common in highly industrialized countries, a possible connection may exist between the increase in the number of cancer cases and the use of azo dyes. Azo dyes can be reduced to aromatic amines by the intestinal microflora. The mutagenicity of a number of azo dyes is reviewed in this paper. They include Trypan Blue, Ponceau 3R, Pinceau 2R, Methyl Red, Methyl Yellow, Methyl Orange, Lithol Red, Orange I, Orange II, 4-Phenylazo-Naphthylamine, Sudan I, Sudan IV, Acid Alizarin Violet N, Fast Garnet GBC, Allura Red, Ponceau SX, Sunset Yellow, Tartrazine, Citrus Red No. 2, Orange B, Yellow AB, Carmoisine, Mercury Orange, Ponceau S, Versatint Blue, Phenylazophenol, Evan's Blue and their degraded aromatic amines. The significance of azo reduction in the mutagenesis and carcinogenesis of azo dyes is discussed.

Nutrition and colonic health: the critical role of the microbiota.

PURPOSE OF REVIEW: To highlight mechanisms whereby diet affects colonic function and disease patterns. RECENT FINDINGS: Topical nutrients are preferentially used by the gut mucosa to maintain structure and function. With the colon, topical nutrients are generated by the colonic microbiota to maintain mucosal health. Most importantly, short chain fatty acids control proliferation and differentiation, thereby reducing colon cancer risk. In patients with massive loss of small intestine, short chain fatty acid production supports survival by releasing up to 1000 kcal energy/day. Human studies show that the microbiota synthesizes a large pool of utilizable folate which may support survival in impoverished populations. Unfortunately, the microbiota may also elaborate toxic products from food residues such as genotoxic hydrogen sulfide by sulfur-reducing bacteria in response to a high-meat diet. The employment of culture-free techniques based on 16S regions of DNA has revealed that our colons harbor over 800 bacterial species and 7000 different strains. Evidence suggests that the diet directly influences the diversity of the microbiota, providing the link between diet, colonic disease, and colon cancer. The microbiota, however, can determine the efficiency of food absorption and risk of obesity. SUMMARY: Our investigations have focused on a small number of bacterial species: characterization of microbiota and its metabolism can be expected to provide the key to colonic health and disease.

Bile acids influence the growth, oestrogen receptor and oestrogen-regulated proteins of MCF-7 human breast cancer cells.

The effects of the major human serum bile acid, glycochenodeoxycholic acid (GCDC), as well as unconjugated chenodeoxycholic acid (CDC), on the MCF-7 human breast cancer cell line have been studied in vitro under oestrogen and bile acid deprived culture conditions. GCDC increased the growth of the breast cancer cells over the range 10-300 microM. At concentrations in excess of the bile acid binding capacity of the medium cell growth was prevented. In contrast 10 microM CDC tended to reduce cell growth. Oestrogen (ER) and progesterone (PgR) receptors, pS2 and total cathepsin D were quantified by monoclonal antibody based immunoassays. Ten to 100 microM GCDC and 10 microM CDC down-regulated ER protein and this was accompanied by induction of the oestrogen-regulated proteins PgR, pS2 and possibly cathepsin D, including increased secretion of the latter two proteins into the culture medium. All these changes were quantitatively similar to those observed with 10 nM oestradiol. The bile acid effects on ER and PgR were not due to interference with the assay procedures. Cells incubated with 50 microM GCDC or 10 microM CDC had higher pmolar concentrations of the bile acids than controls. This study suggests that naturally occurring bile acids influence the growth and steroid receptor function of human breast cancer cells.

Alkylphenols--potential modulators of the allergic response.

The prevalence of allergic diseases has increased in recent decades. Allergic diseases, particularly asthma, are complex diseases with strong gene-environment interactions. Epidemiological studies have identified a variety of risk factors for the development of allergic diseases. Among them, endocrine-disrupting chemicals (EDCs) play an important role in triggering or exacerbating these diseases. 4-Nonylphenol (NP) and 4-octylphenol (OP)--two major alkylphenols--have been recognized as common toxic and xenobiotic endocrine disrupters. Due to their low solubility, high hydrophobicity, and low estrogenic activity, they tend to accumulate in the human body and may be associated with the adverse effects of allergic diseases. Recently, new evidence has supported the importance of alkylphenols in the in vitro allergic response. This review focuses on the effects of alkylphenols on several key cell types in the context of allergic inflammation. Copyright © 2012. Published by Elsevier B.V.