Classic clinical symptoms include rash and inflammation around the mouth and eyes, plus neurological effects that include drowsiness and peripheral neuropathy affecting sensory and motor nerves in the hands and feet. In addition to dietary shortfall, deficiency can be the result of anti-vitamin drugs. There are also rare genetic defects that can trigger vitamin B6 deficiency-dependent epileptic seizures in infants. These are responsive to pyridoxal 5-phosphate therapy. Definition
Vitamin B6 is a water-soluble vitamin, one of the B vitamins. The vitamin actually comprises a group of six chemically related compounds, i.e., vitamers, that all contain a pyridine ring as their core. These are pyridoxine, pyridoxal, pyridoxamine, and their respective phosphorylated derivatives pyridoxine 5-phosphate, pyridoxal 5-phosphate and pyridoxamine 5-phosphate. Pyridoxal 5-phosphate has the highest biological activity, but the others are convertible to that form. Vitamin B6 serves as a co-factor in more than 140 cellular reactions, mostly related to amino acid biosynthesis and catabolism, but is also involved in fatty acid biosynthesis and other physiological functions. Forms
Because of its chemical stability, pyridoxine hydrochloride is the form most commonly given as vitamin B6 dietary supplement. Absorbed pyridoxine (PN) is converted to pyridoxamine 5-phosphate (PMP) by the enzyme pyridoxal kinase, with PMP further converted to pyridoxal 5-phosphate (PLP), the metabolically active form, by the enzymes pyridoxamine-phosphate transaminase or pyridoxine 5-phosphate oxidase, the latter of which also catalyzes the conversion of pyridoxine 5′-phosphate (PNP) to PLP. Pyridoxine 5-phosphate oxidase is dependent on flavin mononucleotide (FMN) as a cofactor produced from riboflavin (vitamin B2).
Cancer prevention
High-molecular-weight macrogol (e.g., 8000 g/mol) has been shown to be a dietary preventive agent against colorectal cancer in animal models. The Chemoprevention Database shows macrogol is the most effective known agent for the suppression of chemical carcinogenesis in rats. Cancer prevention applications in humans, however, have not yet been tested in clinical trials. Other
Macrogol is also used to fuse B-cells with myeloma cells in monoclonal antibody production. References
External links
"Macrogol". Drug Information Portal. U.S. National Library of Medicine.