Effect of Dietary Zinc, Copper and Iron Levels on Superoxide Dismutase, Catalase and Glutathione-S- Transferase Activity

Abstract

The interactions between dietary zinc, copper and iron and their effects on antioxidant enzymes activity [superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST)] were examined. Fifty-four rats weighting approximately between 80-100 grams were divided into nine groups (E1-E9). Each group containing six rats was fed on basal diet with varying amount of Zn (2.5, 35 or 175 mg Zn/kg diet), Cu (1.2, 6.3, or 25 mg Cu/kg diet) and Fe (10, 50 or 230 mg Fe/kg diet). The second group (E2) was fed a diet deficient in all studied elements (2.5mg Zn, 1.2mg Cu, and 10mg Fe per 1 kg diet). The results of E2 showed a decrease in SOD and CAT activity and increase GST in plasma erythrocytes and tissues. Moreover, plasma thiobarbituric acid reactive substances (TBARs) and hydrogen peroxide production in E2 were found to be higher than those in other groups. The high activity of lactic acid dehydrogenase (LDH) in the plasma indicated that cell membrane damage was occurred. This damage was accompanied by elevation of lipid peroxidation and in the same time by reduction of SOD and CAT activity. Supplementation of basal diet with the different concentrations of studied minerals led to improve the activity of antioxidants enzymes (SOD and CAT) and decrease in TBARs and LDH activity.