Herbal Anti-Hyperglycemic Compound Increases Expression of Glucose Transporter Molecules in Diabetic Rats

Abstract

Background: In previous studies, Sharma et al. has already isolated an anti-hyperglycemic compound from the fruit pulp of Eugenia jambolana using HPLC and other chromatographic techniques. However, the effect of anti-hyperglycemic compound (FIIc) on the expression of Glucose transporters and Kv 1.3 potassium channel in Streptozotocin-Nicotinamide induced diabetic rats has not been studied so far. Objective: To study the effect of HPLC purified herbal anti-hyperglycemic compound (FIIc) on the expression of GLUT-4, GLUT-8 and Kv 1.3 potassium channel in Streptozotocin-Nicotinamide induced diabetic rats. Methods: 24 Male Wistar rats were taken and diabetes was induced in group B, C and D rats (n=6 each) by injecting Streptozotocin at a dose of 45 mg/kg of body weight 15 minutes after the administration of Nicotinamide at a dose of 230 mg/kg of body weight, intra-peritoneally to overnight fasted rats. Active compound (FIIc) was orally administered to group C and Pioglitazone to group D at a dose of 20 mg/kg of body weight for 6 weeks respectively. Serum was separated for the estimation of Adiponectin and TNF alpha at week 0 and week 6 of the study. Real time mRNA expression of GLUT-4, GLUT-8 and Kv 1.3 potassium channel was measured and compared between healthy and diabetic control rats. Expression of GLUT-4, GLUT-8 and Kv 1.3 potassium channel was also measured at protein level through Immunohistochemistry and compared between healthy and diabetic controls. Results: After treatment with FIIc for 6 weeks there was a 1.28 folds increase in GLUT-4 mRNA expression in skeletal muscles and 2.67 folds increase in GLUT-8 mRNA expression in liver tissues of group C rats as compared to group B rats. However, Kv 1.3 potassium channel mRNA expression was found to be at par among the four study groups. TNF alpha levels were found to be significantly decreased in group C rats as compared to group B. A slight increase in serum Adiponectin level was observed in group C as compared to group B, which was found to be statistically insignificant. Conclusion: FIIc treatment for 6 weeks significantly increases the expression of GLUT-4, GLUT-8 mRNA expression in liver and skeletal muscles leading to increased peripheral insulin sensitivity.