Hypoglycemic effects and mechanism of mulberry leaves polysaccharide / 中草药

ABSTRACT

Objective: To investigate the hypoglycemic mechanism of mulberry leaves polysaccharide (MLP) in diabetic mice. Methods: Alloxan-induced diabetic model of mice was continuously ig administered with the distilled water, MLP at doses of 0.25, 0.50, and 1.00 g/kg, respectively for six weeks. Body weight was recorded weekly. Blood samples were collected for measurement of blood glucose at the 2nd, 4th, and 6th weekends after fasting for 5 h. Glucose tolerance test was carried out and femoral artery blood was taken to measure the glycosylated serum proteins (GSP) and the blood serum insulin content at the 6th weekend. The liver glycogen, homogenate protein content, hexokinase (HK), pyruvate kinase (PK), SOD, GSH-Px activity, and MDA level were measured in the end of the experiments. Results: Symptoms of diabetic mice fed with MLP were improved. The blood glucose level, the area under curve of the blood glucose, and GSP of diabetic mice fed with MLP decreased obviously. Their blood serum insulin, liver glycogen synthesis, HK secrection, SOD vitality, and body weight increased significantly. However, their MDA content decreased obviously. The PK vitality of diabetic mice fed with MLP at dose of 0.5 g/kg increased significantly, while there was little effect on GSH-Px activity. The ratios of liver, kidney, and spleen to body weight increased obviously in diabetic mice, but decreased obviously in the diabetic mice fed with MLP. Conclusion: It is suggested that MLP has the effects of enhancing their anti-oxidation by increasing SOD vitality and decreasing MDA content in diabetic mice. Through promoting insulin secretion and improving liver HK and PK vitality to promote blood glucose to enter the liver cells, glycogen synthesis, glucose oxidation, and decomposition are accelerated, and MLP can regulate the glucose metabolism, reduce blood sugar, and improve the symptoms in alloxan-induced diabetic mice.