ABSTRACT
Diabetes is one of the most prevalent endocrine disorders. Considering the antidiabetic effect of soybean isoflavones, in this study the effect of daidzein, the most important isoflavone in soybean, on the serum glucose level, lipid profile, and paraoxonase activity in diabetic rats was investigted. Thirty six male Sprague Dawley rats were randomly divided into three groups: 1. healthy, 2. diabetic, and 3. diabetic, supplemented with daidzein. Diabetes was induced in rats by a single injection of streptozotocine [60mg/kg body weight, dissolved in 0.05 mol/l citrate buffer]. It was confirmed when the fasting blood glucose level was above 250 mg/dl. For Group 3, the diet was supplemented with 600 mg diazdein/kg basal diet. The groups of rat were fed their respective diets for three weeks. Supplementation with daidzein had no effect on the fasting glucose level, but, as compared to the diabetic [control] group, it brought about a significant decrease in the triglyceride and low-density lipoprotein levels [P=0.0001]. The high-density lipoprotein levels, too, increased in this group [P= 0.001]. Daidzein had no effect on the paraoxonase enzyme activity, as compared to the control values. However, comparison of the initial and final levels of the activity of this enzyme in the daidzein-supplemented group indicated a positive effect of diadzein in preventing reduction of this enzyme's activity [P=0.0001]. Daidzein may have a desirable effect on the lipid profile disorders, one of the most important complications of diabetes. It can also support the antioxidant system