Modulation of pancreatic β-cells in neonatally streptozotocin-induced type 2 diabetic rats by the ethanolic extract of Momordica charantia fruit pulp

Abstract

Effective doses of the Momordica charantia fruit pulp (MCF) ethanolic extract on pancreatic β-cells modulation in neonatally streptozotocin-induced type 2 diabetic rats were studied. Diabetic rats (n = 8) were treated with MCF extract (400 mg kg⁻¹ day⁻¹) or glibenclamide (5 mg kg⁻¹) for 28 days. Control rats (n = 11) and untreated diabetic rats (n = 8) received only water. Fasting glucose, serum insulin (by ELISA) and β-cell function (HOMA %B by homeostasis model assessment) were measured. β- and α-cells were identified by immunostaining, nuclei by DAPI, and β-cell size and number by morphometry. Significant improvement of fasting blood glucose, serum insulin and β-cell function was observed with the MCF extract for the diabetic rat model. The islet size, total β-cell area and number of β-cells were increased to almost double in the diabetic rats treated with MCF extract as compared to the untreated diabetic rats. The number of α-cells did not change significantly. Insulin granules in β-cells were notably reduced in diabetic islets as compared to control islets. However, extract-treated diabetic rat β-cells were abundant with insulin granules, which was comparable to non-diabetic control islets. The modulation of pancreatic β-cells may be involved in the experimental observation of anti-diabetic effects of M. charantia extract.

Keywords:

• neonatally streptozotocin-induced type 2 diabetes
• Momordica charantia
• pancreatic islets
• β-cells
• modulation
• immunohistochemistry

Acknowledgements

We are thankful to the Higher Education Commission (HEC) of Pakistan for financial support. We highly appreciate the role of Professor M. Mosihuzzaman for helpful discussions, suggestions, encouragement and critical reading of the manuscript. We would also like to thank Professor Dr Muhammad Iqbal Choudhary for encouragement and critical reading of the manuscript. We would like to thank Dr Suad Naheed for helpful discussions. We are thankful to Mr Mumtaz Ali and Mr Sardar Tauseef Shafquat for assistance in the animal handling and Maryam Bano for glibenclamide experiments.