Influence of dietary capsaicin and onion on the metabolic abnormalities associated with streptozotocin induced diabetes mellitus

Effect of feeding 15 mg% capsaicin diet or 3% freeze dried onion powder containing diet were examined in albino rats rendered diabetic with streptozotocin injection. Diabetic rats maintained on onion diet for 8 weeks excreted comparatively less amounts of albumin, urea, creatinine and inorganic phosphorus. Dietary onion also partially reversed the abnormalities in plasma albumin, urea, creatinine and inorganic phosphorus in diabetic animals. Onion also produced a significant reduction in hyperglycemic status of diabetic animals. Diabetic rats maintained on onion diet had a lowered relative liver weight at the end of the study compared to diabetic control group. Diabetic rats fed onion diet also exhibited lowered lipid peroxides in circulation and in urine when compared to diabetic control group. Blood cholesterol was lowered significantly by dietary onion in diabetic animals. Cholesterol decrease was exclusively from LDL-VLDL fraction. Significant decrease in blood phospholipids and tr iglycerides also brought about by dietary onion. Hepatic cholesterol, triglycerides, phospholipids which were elevated under diabetic condition were countered significantly by dietary onion. Dietary capsaicin did not have any significant influence on any of the parameters tested in diabetic rats. Thus, the study reveals that onion feeding improves the metabolic status in diabetic condition, probably because of its hypoglycemic as well as hypocholesterolemic effect. (Mol Cell Biochem 175: 49–57, 1997)