The effect of curcumin on lipid peroxidation and selected antioxidants in irradiated rats
The effect of irradiation on oxidants and antioxidants in selected tissues and a possible protective effect of curcumin on these indices were investigated. A total of 28 rats were divided into 3 groups; group 1 was control; group 2 was the irradiation group, saline was administered intraperiotenally (i.p. for three days and then, 9 Gy gamma irradiation was applied; group 3 was the irradiation curcumin group: curcumin was given i.p. for three days at 200 mg/ kg body weight and then the same dose of irradiation was applied. A significant increase in malondialdehyde (MDA) was detected in the liver, kidney, and brain tissues of the rats as a result of irradiation (P 0.01) Glutathione peroxidase (GSH Px) activity in all the tissues (except for kidneys) decreased (P 0.01) liver SOD (superoxide dismutase) activity decreased (P 0.05) and GSH (glutathione) levels in kidney and ovary tissues (P 0.001) significantly increased. While curcumin administration returned the increased MDA levels in the kidneys and brain in result of irradiation to normal (P 0.01) it did not return the increased MDA levels in the liver tissue to normal (P 0.001) despite significantly reducing them. While decreased GSH Px and SOD activity in the liver in result of irradiation increased with the addition of curcumin (P 0.05) increased GSH levels in the kidneys and ovaries returned to control levels (P 0.001) When MDA values were examined, it was found that the addition of curcumin protected the liver, kidneys and brain from the oxidative damage caused by irradiation. Gamma ray, phenolic compound, oxidative stress Radiation is widely used for radiotherapy, medical diagnosis, dental radiography and several imaging protocols. Its exposure is also in question in accidental radiation releases (Radwan and Mohamed 2018) It has been determined that ionizing radiation causes oxidative stress by generating various reactive oxygen species (ROS) molecules such as superoxide, singlet oxygen, and hydrogen peroxide that have the potential to damage critical cellular elements like DNA, proteins, and membrane lipids and consequently lead to physical and chemical damage in cells, resulting in cell death (Koc et al. 2003) Cells have an important antioxidant defense against ROS. The antioxidant system involves low molecular weight antioxidant molecules like glutathione (GSH) as well as a number of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GSH Px) Excessive production of oxygen metabolites is associated with imbalance between oxidants and antioxidants, causing oxidative stress (El Gazzar et al. 2016) Detrimental effects of irradiation on healthy tissues can be reduced due to the capacity of antioxidants (Okunieff et al. 2008) Antioxidant supplements decrease the side effects induced by the radiation treatment by inhibiting the oxidative damage to normal cells (Lawenda et al. 2008) It has been stated that several dietary antioxidants reduce free radical attack on biomolecules (Duthie et al. 1996) Being a major bioactive compound in turmeric, ACTA VET. BRNO 2018, 87: 379 385; https:/doi.org/10.2754/avb201887040379 Address for correspondence: Assoc. Prof. Mehtap Ozcelik Vocational School of Health Services University of Firat, Elazig, Turkey Phone:+90 532 432 65 81 E mail: mehtapyo@hotmail.com http:/actavet.vfu.cz/ curcumin is a yellow pigment phenolic compound obtained from the roots of turmeric used as spice. It has a wide spectrum of anti oxidant, anti carcinogenic, anti mutagenic, and anti inflammatory properties (Tawfik et al. 2013) Apoptosis is a biological event based on morphological changes that occurs physiologically or pathologically and is regulated by genes (Kerr et al. 1972) The enzymes that control this type of death which is also known as programmed cell death, are known as caspases (Metzstein et al. 1998) Among them, caspase 3 has an important place in the apoptosis mechanism (Korsmeyer 1999; Hugle and Fulda 2015) A correlation between irradiation and caspase 3 expression has been reported in some studies (Ozyurt et al. 2014; Li et al. 2015; Ismail et al. 2016) In liver cancer, hepatic radiotherapy causes irradiation associated liver damage which can be life threatening (Radwan and Mohamed 2018) Cancer radiotherapy and accidental exposure to ionizing radiation require new safe and effective radioprotective agents for the purpose of treating the damage to normal tissue induced by exposure to ionizing radiation. This study investigated how oxidants and antioxidants in the kidney, spleen, heart, brain and ovary tissues along with the liver were affected as a result of irradiation, and whether or not the antioxidant curcumin had a protective effect on these indicators. Materials and Methods