Hypoglycemic and hypolipidemic effects of a polysaccharide from flower buds of Lonicera japonica in streptozotocin-induced diabetic rats

Hyperglycemia and dyslipidemia are classic features for diabetes mellitus (DM). In this study, one fraction of the crude polysaccharides extracted from Lonicera japonica flower buds (LJP) were investigated for its hypolipidaemic and hypoglycaemic activities by means of streptozotocin (STZ)-induced diabetic rats. Interestingly, after orally administrated with 800mg/kg body weight (B.W.) LJP for 42 days, the food and water intake and the levels of sugar and insulin in blood for the diabetic rats were drastically decreased, while the contents of liver and skeletal muscle glycogen and the concentrations of hepatic pyruvate kinase and hexokinase were obviously increased (p<0.01 or p<0.05). The levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein-cholesterin (LDL-C) and very-low-density lipoprotein-cholesterin (VLDL-C) were significantly descended, while high-density lipoprotein-cholesterin (HDL-C) was significantly ascended (p<0.01 or p<0.05). In addition, the oxidant stress in liver was restored as well. The results suggested that LJP could be considered as an ingredient of functional foods for diabetes, and this is the first report about the hypoglycemic and hypolipidemic effects of the polysaccharides extracted from Lonicera japonica.