Hypoglycemic Effect of Nelumbo Nucifera Seed Extract on GLUT-4 mRNA and GLUT-4 Protein in Streptozotocin-Induced Diabetic Rats

BACKGROUND: To investigate the effect of N. nucifera hydroalcoholic seed extract on fasting blood glucose (FBG) levels, glucose transporter (GLUT)-4 mRNA, and GLUT-4 protein in the adipose tissue of streptozotocin (STZ)-induced diabetic rats. MATERIALS AND METHODS: Male Sprague Dawley (SD) rats were first fed with a high-fat diet (HFD) for three weeks, and then, diabetes was induced by intraperitoneal injection of STZ at a dose of 35 mg/kg bw. Rats were divided into four groups: group 1: normal rats (NC), group 2: STZ-induced diabetic rats (DC), group 3: diabetic rats with N. nucifera hydroalcoholic seed extract at a dose of 400 mg/kg bw (NN), and group 4: diabetic rats with metformin at a dose of 100 mg/kg bw (MET) for 28 days. RESULTS: FBG level was significantly lower in the NN group than in the DC group (P < 0.05). Also, the NN group increased GLUT-4 mRNA expression and GLUT-4 protein in the adipose tissue when compared to the diabetic group. CONCLUSION: We conclude that the observed hypoglycemic effect of N. nucifera seed extraction in STZ-induced diabetic rats could be due to insulinomimetic activity.