INVESTIGATION OF HYPOGYCEMIC AND HYPOLIPIDEMIC EFFECTS OF AN AQUEOUS EXTRACT OF LUPINUS ALBUS LEGUME SEED IN STREPTOZOTOCIN-INDUCED TYPE I DIABETIC RATS.

Abstract

Background: Lupinus albus (LA) seed is a legume food used traditionally for the treatment of diabetes. The aim of this study was to investigate the effects of an aqueous extract of LA on lipid and glucose levels in normal and STZ induced Type 1 diabetic rats. Methods: Aqueous extract of LA was prepared and used for animal treatments. Diabetes was induced by a single intraperitoneal injection of streptozotocin (60mg/kg body weight). Effects of LA on oral glucose tolerance in normal and diabetic rats were investigated by giving a single dose of distilled water (controls), 200 or 400mg/kg LA extract, metformin 300mg/kg or glibenclamide 500µg/kg after 12 hours of fasting (time 0 glucose). After 15 minutes, a glucose load (3g/kg) was given. Glucose levels were measured at 30, 60, and 120 minutes after glucose loading. To investigate long term effects, animals were given similar treatments daily for 4 weeks. At the end of the study, serum glucose, insulin, total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL-C), very low density lipoprotein (VLDL-C) and high density lipoprotein (HDL-C) cholesterol levels were measured or calculated. Results: LA demonstrated significant (P<0.001) hypoglycaemic effects in normal rats but not in diabetic rats after acute and long term treatment. Normal LA treated rats showed higher (P<0.001) insulin levels compared to normal controls but insulin remained very low in diabetic rats. Diabetic rats showed diabetes associated weight loss in both treated and untreated rats. However, LA was effective in reducing atherogenic lipid levels (TC, TG, LDL-C VLDLC; P<0.001) with no change (P>0.05) in HDL-C. Conclusion: We conclude that the use of Lupinus albus among various communities may not be effective in treating hyperglycaemia in type 1 diabetes but effective for treating diabetes induced dyslipidemia.