Abstract:The aim of this study was to investigate the anti-diabetic effects of active peptide P3 from tartary buckwheat on streptozotocin（STZ）-induced diabetic model mice.The hypoglycemic effect of peptide P3 on αglucosidase was first evaluated in an in vitro hypoglycemic experiment.Then，for the animal experiment，60 male C57/BL6 mice were randomly divided into the following six groups（10 mice each）：the blank，model，positive control（pioglitazone）；and low，middle and high dose peptide P3 groups.All groups，except the blank group，were administered STZ（50 mg/kg by intraperitoneal injection）on 3 consecutive days to establish the diabetic animal model.The positive control group was administered pioglitazone（20 mg/kg daily by gavage），and the low，medium and high dose peptide P3 groups were administered peptide P3 daily（at 5，10 mg/kg and 20 mg/kg，respectively，by intraperitoneal injection）.All treatments continued for 4 weeks.Then，the animals were evaluated by conducting an oral glucose tolerance test（OGTT）and measuring fasting blood glucose and serum triglyceride（TG），cholesterol（TC），high-density lipoprotein（HDL-C）and low-density lipoprotein（LDL-C）levels.Expression levels of insulin signaling pathway-related proteins in the liver were detected by western blotting.Compared with the model group，glucose tolerance in the medium and high dose peptide P3 groups were significantly improved in a dose-dependent manner（P＜0.05）；fasting blood glucose in the medium and high dose peptide P3 groups was significantly decreased（P＜0.05）；serum TG，TC and LDL-C in the peptide P3 groups were significantly decreased（P＜0.05）；and serum HDL-C was significantly increased（P＜0.05）.The expression levels of PI3K and GLUT4 in the liver tissues of mice in the peptide P3 groups were significantly upregulated （P＜0.01）in a dose-dependent manner when compared with the model group.Peptide P3 reduced blood glucose and lipid levels and improves insulin resistance in diabetic mice.