Abstract: To investigate the effects of different effective parts of Morus nigra leaves extract on sugar and lipid metabolism in type 2-diabetic mice.Diabetic mouse was induced by combined use of high fat-glucose diets and low dose streptozotocin (STZ),which was randomly divided into 8 groups with one normal control group reference to their weight and blood glucose levels.Eight groups were as follows:high-dose group of mulberry leaves aqueous extract (AE-HD),middle-dose group (AE-MD),low-dose group (AE-LD),high-dose group of total alkaloids group (TA-HD),middle-dose group (TA-MD),low-dose group (TA-LD),model control group and positive (Rosiglitazone) control group.The intragastric administration lasted for 4 weeks,the oral glucose tolerance test was performed after 2 weeks of administration,the levels of fasting blood glucose,insulin level,triglyceride (TG),low density lipoprotein-cholesterol (LDL),SOD and MDA were detected.The insulin resistance index (HOMA-IR) were investigated with these models.In comparison with the model group,the mulberry leaves aqueous extract groups and total alkaloids groups (1.2 g/kg,0.6 g/kg,0.3 g/kg) obviously depressed fasting blood glucose of type 2-diabetes mice (P<0.05, P<0.01),but there was no influence on normal group;The aqueous extract groups and total alkaloids can improve insulin and glucose tolerance of type 2-diabetes mice,and obviously regulate down fasting blood lipid of these mice.Hypoglycemic effect of different parts of M.nigra leaves extract had been shown in this study,and the mulberry leaves aqueous extract groups has the most obvious effects on depressing fasting blood glucose,lipid and insulin resistance index of type 2-diabetes mice.

Key words: Morus nigra Linn, type 2-diabetes mice, hypoglycemic effect, lipid metabolism