Effects of Allium Vegetable Intake on Levels of Plasma Glucose, Lipid and Minerals in Streptozotocin Induced Diabetic Rats

ABSTRACT

The effects of Allium vegetables on blood glucose levels and lipid metabolism in streptozotocin (STZ) induced diabetic rats were investigated. Diabetes mellitus was induced by STZ injection (45 mg/kg b.w.) into the tail vein. Sprague-Dawley rats weighing 220+/-10 g were randomly assigned to 7 groups normal, STZ-control and five Allium groups (Allium cepa, Allium fistulosum, Allium sativum, Allium tuberosum and Allium victorialis) . Normal and STZ-control groups were fed an AIN-93 diet and five Allium groups were fed a modified diet containing 10% Allium powder each for 4 weeks. Body weight, diet intake, food efficiency ratio (FER) and organ weights were monitored. Activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were observed. Plasma levels of glucose, free fatty acid, triglyceride and HDL-cholesterol were analyzed. Levels of glycogen, cholesterol and triglyceride in liver were determined. Levels of malondialdehyde (MDA) in liver, lung, kidney, and pancreas were assayed. The hepatic contents of chromium (Cr) , iron (Fe) , zinc (Zn) and manganese (Mn) were measured. The Allium sativum group had weight gain and suppressed a hypertrophy of the kidney significantly. The activity of ALT was significantly lowered in the diabetic groups except Allium sativum group compared to STZ-control group. The Allium sativum and Allium tuberosum groups showed the hypoglycemic effects at 4 weeks. There were no significant differences between the control and all the other diabetic groups in the plasma levels of cholesterol, HDL-cholesterol, triglycerides and free fatty acids. Most of the Allium groups except Allium fistulosum were observed significantly lowered level of MDA in the lung compared to STZ-control group. The diabetic rats fed the Allium cepa and Allium sativum have shown significantly lowered hepatic Zn contents. The results suggested that the intake of the Allium vegetables may be effective in the antihyperglycemia by lowering blood glucose levels.