Antioxidant enzyme activities were determined in erythrocytes, sera and liver tissue. The tissue samples were homogenised in 1.15% potassium chloride (KCl, pH=7.4) solution for 5 min, then, centrifuged at 5,000×g for 15 min at 4 °C and the supernatant transferred to micro tubes until antioxidant enzyme determinations. The activity of SOD was determined by using xanthine and xanthine oxidase to generate superoxide radicals in reaction with 2-(4-iodophenyl)-3-(4-nitrophenol)-5-phenyltetrazolium chloride (INT) to form a red formazan dye. The activity of SOD was measured by units of degree of inhibition of this reaction using colorimetric methods . The activity of GSH-Px in tissue was measured using the method described by Paglia and Valentine (1967). The activity of CAT was determined at room temperature by using the method of Aebi (1984) and absorbance of the sample was measured at 240 nm for 30 s in a spectrophotometer (Jasco, V570, Tokyo, Japan). Total antioxidant capacity was determined using Randox total antioxidant status kit. The serum and liver tissue concentration of MDA, an index of lipid peroxidation and oxidative stress, was determined using the thiobarbituric acid reactive substances (TBARS) method . The principle is that TBARS reacts with MDA to form a stable pink colour measured spectrophotometrically at 532 nm.