The Role of Antioxidant (Vitamin E) in the Control of Lead (Pb) Pollution and Ehancement of Growth Within Nile Tilapia (Oreochromis niloticus)

The present study was undertaken to investigate whether treatment with vitamin E (VE) protects against intoxication induced by lead (Pb) exposure in Oreochromis niloticus. Fish were exposed for 60 days to a 10 mg Pb / Kg diet. The oxidative stress affected by Pb in fish was treated by antioxidant (VE) supplementation. Fish were assigned to four dietary groups. The diets differed in their constituents of Pb and VE. Growth hormone (GH) levels were significantly increased (p<0.05) in fish fed the VE supplemented diet and decreased in fish fed the Pb supplemented diet reference to control. The supplementation of VE with Pb reduced the accumulation of that metal in muscle and prevented its negative impact on growth when compared with control. The treatment with dietary VE reduced Pb concentrations in muscles and increased GH levels in serums of Pb treated fishes. While diets devoid of that antioxidant (VE) showed reduced GH levels in serums and increased Pb concentrations in muscles of these fishes. These observations suggest that VE has a definite role in the prophylaxis of Pb poisoning, and that GH levels may be considered a sensitive bioindicator of Pb pollution and of antioxidant defence in fish.