Modulatory effects of curcumin on γ-radiation-induced cellular damage in primary culture of isolated rat hepatocytes

Ionizing radiation is known to induce oxidative stress through generation of reactive oxygen species (ROS) resulting in imbalance of the pro-oxidant and antioxidant in the cells, which is suggested to culminate in cell death. The present work was aimed to evaluate the radioprotective effect of curcumin, a yellow pigment of turmeric on gamma-radiation-induced toxicity in primary cultures of isolated rat hepatocytes. Hepatocytes were isolated from the liver of rats by collagenase perfusion. The cellular changes were estimated using lipid peroxidative indices like thiobarbituric acid reactive substances (TBARS), the antioxidants superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and reduced glutathione (GSH), ceruloplasmin, vitamins A, E and C and uric acid. The comet assay is a sensitive and rapid technique for quantifying and analyzing DNA damage in individual cells was exposed under gamma-radiation. The increase in the severity of DNA damage was observed with the increase dose (1, 2 and 4 Gy) of gamma-radiation in cultured hepatocytes. TBARS were increased significantly, whereas the levels of GSH, vitamins C, E and A, ceruloplasmin, uric acid and antioxidant enzymes were significantly decreased in gamma-irradiated hepatocytes. The maximum damage to hepatocytes was observed at 4 Gy irradiation. On pretreatment with curcumin (1, 5 and 10 mu g/ml) showed a significant decrease in the levels of TBARS and DNA damage. The antioxidant enzymes were increased significantly along with the levels of GSH, vitamins A, E and C, uric acid and ceruloplamin. The maximum protection of hepatocytes was observed at 10 mu g/ml of curcumin pretreatment. Thus, pretreatment with curcumin helps in protecting the hepatocytes against gamma-radiation-induced cellular damage and can be developed as an effective radioprotector during radiotherapy in near future. (c) 2007 Elsevier B.V. All rights reserved.