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 defi-cient 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 sub-stances (TBARs) and hydrogen peroxide produc-tion in E2 were found to be higher than those in other groups. The high activity of lactic acid de-hydrogenase (LDH) in the plasma indicated that cell membrane damage was occurred. This dam-age was accompanied by elevation of lipid peroxi-dation and in the same time by reduction of SOD and CAT activity. Supplementation of basal diet with the different concentrations of studied miner-als led to improve the activity of antioxidants en-zymes (SOD and CAT) and decrease in TBARs and LDH activity.