en پژوهشي Research Article The present study determines the efficacy of N-acetyl cysteine (NAC) on marker enzymes, lipid peroxidation and antioxidants in carbon tetrachloride induced hepatotoxicity in rats. Carbon tetrachloride (CCl4) (3 mL/kg/week) administered subcutaneously to albino Wistar rats for a period of three months significantly increased the activities of marker enzymes in plasma such as aspartate transaminase, Gama-glutamyl transferase and alkaline phosphatase and increased the levels of thiobarbituric acid reactive substances and hydroperoxides in plasma and tissues (liver and kidney). A significant decrease in the levels of plasma antioxidants (glutathione, vitamin C and vitamin E) was also noted. Further, a decrease in the concentration of glutathione and the activities of superoxide dismutase, catalase and glutathione peroxidase in the tissues were observed. N-acetyl cysteine (150 mg/kg) was orally administered to normal and carbon tetrachloride-treated rats for a period of three months. N-acetyl cysteine decreased the activities of marker enzymes, lipid peroxidation and improved the antioxidant status in carbon tetrachloride-treated rats. But there were no significant alterations in these parameters in normal rats treated with N-acetyl cysteine. Histopathological observations of the liver also showed the protective effect of N-acetyl cysteine in carbon tetrachloride-induced hepatotoxicity in rats. The results of this study show the protective action of N-acetyl cysteine in carbon tetrachloride-induced hepatotoxicity in rats. This is mainly due to the effective antioxidant potential of N-acetyl cysteine. 118 0 http://ijpt.iums.ac.ir/browse.php?a_code=A-10-100-70&slc_lang=en&sid=1 Narasimhanaidu Kamalakkannan 1003194753284600204 1003194753284600204 No Rajagopalan Rukkumani 1003194753284600205 1003194753284600205 No Kode Aruna 1003194753284600206 1003194753284600206 No Penumathsa Suresh Varma 1003194753284600207 1003194753284600207 No Periyasamy Viswanathan 1003194753284600208 1003194753284600208 No Venugopal Padmanabhan Menon 1003194753284600209 1003194753284600209 No