Administration of Combined Methanolic Leaf Extracts of Vernonia amygdalina and Gongronema latifolium Enhanced Glut 2 Expression in the Pancreas and Downregulates Serum Caspase 3 Activity of Streptozotocin-Induced Diabetic Wistar Rats

Abstract

Aim: The study evaluated the effects of the combined extracts of Vernonia amygdalina (VA) and Gongronema latifolium (GL) on pancreatic GLUT 2 expression and caspase 3 activity in streptozotocin (STZ, 45 mg/Kg)-induced diabetic rats. Study Design: Fifteen Albino rats were used for the study and were placed in 3 groups of 5 rats each: A - normal control, B – Diabetic control and C – experimental group. Place and Duration of Study: The study was carried out in the department of Anatomy, University of Calabar. Duration:  6 months. Methodology:  Half of the diabetic rats were treated with VA+GL (400mg/kg, ratio 1:1, DE group) for 28 days, while the other half was untreated and served as diabetic control (DC). Normal control (NC) rats were untreated. After 28 days, the rats were sacrificed and their blood glucose, serum GLUT 2 and caspase 3 activity were measured.  Histochemical evaluation of the pancreas was also carried out. Results: Blood glucose concentrations for the 3 groups were 60.31±7.28, 257.00±4.43, and 116.60±10.11 mg/dl for NC, DC and DE respectively. This represented a 4-fold increase in the DC compared with NC and a significant amelioration in the extract-treated DE group compared with DC group. Serum GLUT 2 concentrations were 70 ng/ml in NC, dropped to 8 ng/ml (p<0.05) in the DC and recovered to 20 ng/ml in DE (p<0.05). Serum caspase was 3.2 ng/ml for NC, increased to 8.5 ng/ml in DC (p<0.05) and reduced to 1.8 ng/ml in DE (p<0.05). The histology of the pancreas showed distorted, degenerated and shrunken β-cells mass in DC compared with NC and DE groups. The DE group showed clear signs of regeneration of the islet cells which was corroborated by positive Feulgen’s reaction compared with the DC group. Conclusion: The data suggests that the combined VA+GL extract has the potential to effectively reverse pancreatic damage in diabetes.