Effectiveness of Zinc in Modulating the CCl (4) - Induced Oxidative Stress in Rat Liver.

The present study was designed to evaluate the role of zinc on the enzymes involved in oxidative defense mechanism in conditions of carbon tetrachloride (CCl (4)) -induced rat liver toxicity. To carry out the study, rats were divided into four groups: group I (normal control), group II (CCl (4) treated), group III (zinc control), and group IV (zinc + CCl (4) treated). Animals in group II and group IV were administered 0.1 mL of CCl (4) mixed with 0.1 mL of groundnut oil on alternate days for a period of 8 weeks. Zinc in the form of zinc sulphate was given to animals of group II and group IV at a dose level of 227 mg/L in drinking water. Animals given CCl (4) treatment alone showed a significant increase in the activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), and the concentration of malondialdehyde (MDA) product, whereas a significant depression was observed in the levels of reduced glutathione (GSH). Zinc treatment to CCl (4) -treated rats brought the altered levels of GSH, MDA, and SOD as observed following CCl (4) -treatment alone to within normal limits. However, the activities of catalase and glutathione peroxidase, which were increased under carbon tetrachloride treatment, were significantly attenuated and tended to become normal. Hence, the present study suggests that zinc may play an important role in regulating the activities of the enzymes involved in antioxidative defense system under CCl (4) toxic conditions.