Protective effects of zinc on oxidative stress enzymes in liver of protein deficient rats.

This study was designed to evaluate the protective effects of zinc on the liver activities of antioxidant enzymes in protein-deficient rats. Zinc sulfate at a dose level of 227 mg/l in drinking water was administrated to Sprague Dawley normal control as well as to protein-deficient rats for a total duration of eight weeks. The effects of zinc treatment and protein deficiency alone as well as combined were studied on rat liver antioxidant enzymes which included catalase, glutathione peroxidase (GPX), glutathione reductase (GR), superoxide dismutase (SOD), and glutathione S-transferase (GST). Protein deficiency in normal rats resulted in a significant increase in hepatic lipid peroxidation and in catalase, Gpx, GR and GST activity. A significant inhibition in the levels of SOD activity and reduced glutathione (GSH) was observed following protein deficiency in normal rats. Zn treatment to protein deficient animals lowered lipid peroxidation and catalase, Gpx and GST activities, and also resulted in a significant elevation in the levels of GSH and SOD activity. The concentration of zinc decreased significantly in protein deficient animals but returned to normal levels when zinc was administered.