Antioxidant and Hepatoprotective Effects of Vitamin E and Melatonin Against Copper-Induced Toxicity in Rats

Abstract

Purpose: To determine the preventive effects of vitamin E and melatonin against acute copper toxicity in rats. Methods: A total of 28 Wistar albino rats were randomly divided into four equal groups: control, copper sulfate, copper sulfate + vitamin E, and copper sulfate + melatonin. The following were analyzed in all groups: serum enzymes; activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), protein carbonyl (PC) content. Liver histopathology was also evaluated. Results: PC levels decreased in rats administered copper sulfate/vitamin E and copper sulfate/melatonin. The activities of SOD, GPx and CAT increased significantly with melatonin and vitamin E administration when compared with administration of copper sulfate alone. Histopathologic features revealed severe degeneration and necrotic changes in rats administered copper sulfate alone. These changes were observed to a lesser extent in the copper sulfate + melatonin group and only minimally in the copper sulfate + vitamin E group. Conclusion: Vitamin E and melatonin are protective against liver damage caused by copper. Vitamin E, and melatonin may strengthen the antioxidant defense system by inhibiting protein oxidation and enhancing the activity of antioxidant enzymes.