Antioxidant effect of tetrahydrocurcumin in streptozotocin–nicotinamide induced diabetic rats

Oxidative stress has been suggested to be a contributory factor in development and complication of diabetes. In the present study, we have investigated the effect of tetrahydrocurcumin (THC), one of the active metabolites of curcumin on antioxidants status in streptozotocin–nicotinamide induced diabetic rats. Oral administration of THC at 80 mg/kg body weight of diabetic rats for 45 days resulted in significant reduction in blood glucose and significant increase in plasma insulin levels. In addition, THC caused significant increase in the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase, reduced glutathione, vitamin C and vitamin E in liver and kidney of diabetic rats with significant decrease in thiobarbituric acid reactive substances (TBARS) and hydroperoxides formation in liver and kidney, suggesting its role in protection against lipid peroxidation induced membrane damage. These biochemical observations were supplemented by histopathological examination of liver and kidney section. The antidiabetic and antioxidant effects of THC are more potent than those of curcumin at the same dose. Results of the present study indicated that THC showed antioxidant effect in addition to its antidiabetic effect in type 2 diabetic rats.