Dietary rice bran improves the glycemic response in rats with streptozotocin-induced diabetes

A 2 × 2 factorial experimental design was employed to evaluate the effect of a fiber-rich rice bran diet on blood glucose, lipid and diabetic nephropathy in streptozotocin (STZ)-induced diabetic rats. Forty male adult Wistar rats were randomly divided into four groups, two of which were injected with nicotinamide and STZ to induce diabetes. Both normal and STZ-diabetic rats were fed AIN-76 diets and rice bran diets (20 g/100 g diet). After 4 weeks of feeding, STZ-diabetic rats both with and without rice bran were significantly (p <0.05) hyperglycemic. Blood fructosamine was ameliorated in rice bran diet-fed STZ-diabetic rats, compared with the baseline. STZ-diabetic rats fed a rice bran diet had a significantly lower blood glucose response than those fed the diet without rice bran. Blood total cholesterol was higher than baseline in AIN-76 diet-fed STZ-diabetic rats, but it had not changed in rice bran diet-fed STZ-diabetic rats. In STZ-diabetic rats, blood creatinine and proteinuria were significantly higher than in nondiabetic rats. These results suggest that a rice bran diet is effective in lowering blood fructosamine and improving the glucose response, but it cannot retard the development of diabetic nephropathy in STZ-diabetic rats.