Effect of alpha-tocopherol on the microsomal lipid peroxidation induced by doxorubicin: influence of ascorbic acid

alpha-Tocopherol (40 mg/rat/day) was administered, orally, to doxorubicin treated rats (2 mg/kg, twice weekly, for 4 weeks) singly and also in combination with ascorbic acid (1 g/100 ml/day) in drinking water. The vitamin therapy was carried out for a period of 1 month. The microsomal lipid peroxide levels in liver and heart were found to be increased in doxorubicin treated rats. alpha-tocopherol and ascorbic acid treatment decreased the lipid peroxide level and also NADPH-dependent lipid peroxidation. A significant depletion of glutathione in liver and heart of doxorubicin treated animals was found to be ameliorated by vitamin therapy. Ascorbic acid was found to maintain the level of microsomal alpha-tocopherol. The activities of the detoxifying enzymes like catalase, superoxide dismutase and glutathione peroxidase were suppressed in doxorubicin treated rats and vitamins coadministration maintained the levels of these enzymes. Ascorbic acid was found to potentiate the antioxidant nature of alpha-tocopherol.