The effect of vitamin C and cobalt supplementation on antioxidant status in healthy and diabetic rats

In the present study, liver, lung, heart and kidney superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) activities, lipid peroxidation, nitrite and vitamin C levels were investigated in diabetic rats. Diabetes induced in rats by streptozotocin (STZ) and the treated rats were received 1 g/l vitamin C with 0.5 mM CoCl2 in drinking water for eigth weeks. In all tissues, superoxide dismutase, glutathione peroxidase, catalase activities, lipid peroxidation and nitrite levels were significantly increased in diabetic rats at the end of 8th week (p < 0.05) whereas vitamin C level was decreased compared to those of controls. Cobalt with vitamin C treatment of diabetic rats resulted in partial restoration of SOD and CAT activities, thiobarbituric acid reactant substances (TBARS), vitamin C and nitrite levels at all times studied, whereas treatment did not significantly change GSH-Px activity compared to diabetics. These results suggest that cobalt with vitamin C, effectively but could not completely restore the altered endogenous defense systems in diabetic rat liver, lung, heart and kidney tissues.