Comparative investigation for hypoglycemic effects of polysaccharides from four substitutes of Lonicera japonica in Chinese medicine

The polysaccharide fractions were obtained from flower buds of the four substitutes of Lonicera japonica, L. macranthoides (LMPB), L. hypoglauca (LHPB), L. fulvotomentosa (LFPB) and L. confuse (LCPB), and their hypoglycemic effects were investigated. In study, streptozocin (STZ)-induced diabetic rats were orally administrated once daily with LMPB, LHPB, LFPB and LCPB (each 800 mg/kg) for 42 days. Reduction for food and water intake (p < 0.05, p < 0.01) and levels of sugar and insulin (p < 0.01, p < 0.05) in blood, as well as elevation for contents of liver and skeletal muscle glycogen (p < 0.05) and concentrations of hepatic pyruvate kinase and hexokinase (p < 0.01, p < 0.05) were observed. Together with significant decline of total cholesterol (TC, 45.8 51.0%, p < 0.05), total triglyceride (TG, 50.6-53.8%, p < 0.01), low-density lipoprotein-cholesterin (LDL-C, 71.2-76.3%, p < 0.01) and very-low-density lipoprotein-cholesterin (VLDL-C, 45.2-50.0%, p < 0.01), the significant rise of high-density lipoprotein-cholesterin (HDL-C, 21.6-24.3%, p < 0.05) were also demonstrated. Consequently, the four polysaccharide fractions displayed notable hypoglycemic effects, similar to that of the polysaccharide fraction from L. japonica (LJP), so that they can be also considered as ingredients of functional foods for type-2 diabetes mellitus (T2DM).