Indian J Physiol Pharmacol 2000; 44 (4) : 401-410 EFFECTS OF EXOGENOUS VITAMIN C ON ETHANOL TOXICITY IN RATS M. V. SURESH, BINDU MENON AND M. INDIRA* Department of Biochemistry, University of Kerala, Thiruvananthapuram - 695 001 (Received on November I, 1999) Abstract: The effect of a mega dose of ascorbic acid (200 mg/lOO g body wt.) on alcohol-induced toxicity in rats was evaluated. In rats administered alcohol and ascorbic acid, malondialdehyde (MDA), hydroperoxide and conjugated dienes decreased in comparison with that given alcohol alone. The reduced activities of scavenging enzymes, ego superoxide dismutase (SOD) and catalase, in ethanol-administered rats were also enhanced by the co-administration of ascorbic acid and ethanol. Co-administration of ethanol and ascorbic acid reduced phospholipids and MDA levels of the erythrocyte membrane in comparison with that of the ethanol fed rats. The reduction in the activities of glutamic oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT), gamaglutamyl transpeptidase (GGT) and the decrease in triglycerides levels also clearly showed the protective action of ascorbic acid in reducing ethanol induced toxicity. Key words: ascorbic acid lipid peroxidation INTRODUCTION Acute and chronic ingestion of ethanol causes a variety of changes in the liver (1, 2). Chronic ethanol consumption has been associated with increased lipid peroxidation manifested by an increase in the level of malondiadehyde (MDA) in the liver (3). Increased lipid peroxidation could occur as a consequence of induction of microsomal membrane free radical generation and also due to depletion of hepatocyte lipid peroxidation defences. In acute ethanol intoxication, liver microsomal metabolism of ethanol was accompanied by OH generation by the "Corresponding Author ethanol antioxidant erythrocyte membrane cytochrome p 450 system. Hydroxyl radicals are responsible for the conversion of ethanol to acetaldehyde (3). Vitamin C is a terminal water-soluble small antioxidant that protects lipids against peroxidation (4). Low leucocyte levels of vitamin C as a measure of tissue stores were found in patients with alcoholic cirrhosis (5). In vitro studies have shown that low-density lipoprotein oxidation can be prevented by naturally occurring antioxidants such as vitamin C, vitamin E, carotenes, etc (6). Chakraborthy et al (7) have shown that ascorbate protects guinea pig tissues against peroxides both in vivo and in vitro. So in this study