Effects of ascorbic acid and a-tocopherol on arsenic-induced oxidative stress

Arsenic is an ubiquitous element in the environment causing oxidative burst in the exposed individuals leading to tissue damage. Antioxidants have long been known to reduce the free radical-mediated oxidative stress. Therefore, the present study was designed to determine whether supplementation of a-tocopherol (400 mg/kg body weight) and ascorbic acid (200 mg/kg body weight) to arsenic-intoxicated rats (100 ppm in drinking water) for 30 days affords protection against the oxidative stress caused by the metalloid. The arsenic-treated rats showed elevated levels of lipid peroxide, decreased levels of non-enzymatic antioxidants and activities of enzymatic antioxidants. Administration of a-tocopherol and ascorbic acid to arsenic-exposed rats showed a decrease in the level of lipid peroxidation (LPO) and enhanced levels of total sulfhydryls, reduced glutathione, ascorbic acid and a-tocopherol and so do the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glucose-6-phosphate dehydrogenase to near normal. These findings suggest thata-tocopherol and ascorbic acid prevent LPO and protect the antioxidant system in arsenic-intoxicated rats.