Effect of genistein isoflavone on glucose lipid profile and paroxonase enzyme activity in diabetic rats

It is known that oxidative stress plays an important role in the pathogenesis of diabetes. Consequently, use of antioxidant for treating and preventing complications of this disease is believed to be beneficial. Considering the antioxidant effects of soy isoflavones, this study was initiated to determine the effects of genistein, one of the isoflavones in soybeans, on serum glucose, lipid profile, and paraoxonase activity in diabetic rats. Thirty-six male Sprague Dawley rats were divided randomly into three groups, in 2 of which diabetes was induced by intravenous injection of 60 mg/kg body weight stereptozotocine dissolved in a 0.05 mol/liter citrate buffer; the criterion for diabetes was a plasma glucose level above 250 mg/dl. All the 3 groups were fed a standard diet for 3 weeks, genistein (95% purity) being added to the diet of one of the diabetic groups at a level of 600 mg/kg diet. Fasting blood samples from the tail were taken at baseline and at the end of the period for measuring glucose, lipids, and paraxonase activity. The statistical test used for data analysis and inter-group comparisons was ANOVA. Supplementation with genistein had no statistically significant effects on the serum paraxonase activity or glucose level, but it brought about significant decreases in the serum triglyceride and total, HDL- and LDL-cholesterol levels. Genistein can potentially have a beneficial effect on diabetes-induced dyslipidemia