Protective effect of pre-supplementation with selenium on cadmium-induced oxidative damage to some rat tissues

The effect of the antioxidant nutrient selenium, Se, on biologic response to cadmium-induced oxidative cytotoxicity was investigated in rats pretreated with Se prior to exposure to mild doses of Cd. Male wistar strain rats (200-250 g b.wt) were exposed to a single daily oral dose of cadmium (3 mg CdCl2/kg) in drinking water for five days following a 15-day oral supplementation with Se (3.0 or 3.5 mg SeO2/kg/day) in drinking water at the end of which membrane lipid peroxidation, ascorbic acid and glutathione contents and activities of antioxidant enzymes catalase, superoxide dismutase, and glutathione peroxidase were determined in the red blood cell, liver and kidney samples obtained from treated animals. Cadmium content was determined in liver and kidney samples. Results showed that pre-supplementation with Se effectively countered Cd-induced membrane lipid peroxidation, depletion of non-enzymic antioxidants, ascorbic acid, and glutathione, and induction of antioxidant enzymes catalase, superoxide dismutase, and glutathione peroxidase in the RBC, liver and kidney as well as reduced Cd accumulation in the liver and kidney, all of which effects are consistent with a protective effect of Se against Cd-induced oxidative cytotoxic damage. RBC was the most susceptible to the inhibitory effect of Se pre-supplementation on Cd-induced lipid peroxidation and tissue ascorbic acid and glutathione depletion.Keywords: Cadmium, selenium, lipid peroxidation, antioxidant enzymes, non-enzymes endogenous antioxidant