Objective: To investigate the hypoglycemic effect of polysaccharide from bovine heart persimmon leaf in diabetic mice model induced by streptozotocin. Method: Diabetic mice model was established by injection of streptozotocin

then the mice were randomly divided into 5 groups: model group

dimethyldiguanide group (0.32 g·kg-1)

low-

medium-and high-dosage groups of polysaccharide of bovine heart persimmon leaf (0.3

0.6

1.2 g·kg-1). The drugs were given to mice daily for 15 consecutive days. Fasting was carried out before administration for 12 h at the end of 15 days. The blood sample was collected via evulseing the mice eyes

and centrifuged to obtain serum for test. Glucose oxidase (GOD) was used to examine the index of glycemia for fasting plasma glucose(FBG); the levels of free fatty acids(FFA) and glutathione(GSH) in serum as well as the contents of total superoxide dismutase(T-SOD)and malondialdehyde(MDA) in liver tissue were tested by biochemical method. The expressions of IRS-1

INSR in pancreas were measured using Western blot analysis. Result: Compared to model control group

the polysaccharide could significantly decrease the level of blood-sugar in diabetic mice

the difference was statistically significant (P<0.05)

and increase GSH level in serum

while reduce the NEFA level

difference was statistically significant (P<0.05). Compared with the model

the polysaccharide could also elevate T-SOD level in liver tissue

while reduce the content of MDA

difference was statistically significant (P<0.05). It also up-regulated the levels of INSR

IRS-1 protein in pancreatic tissue

difference was significant (P<0.05). Conclusion: The polysaccharide of bovine heart persimmon leaf can play the role of hypoglycemic activity though the mechanism may be related to the protective effect of lipid peroxidation injury in liver tissue and to improve INS signal transduction pathway in the pancreatic tissue of diabetic mice.