GLP-I secretion in healthy and diabetic Wistar rats in response to aqueous extract of Momordica charantia

Abstract

BackgroundDiabetes mellitus is one of the major global health disorders increasing at an alarming rate in both developed and developing countries. The objective of this study was to assess the effect of aqueous extract of Momordica charantia (AEMC) on fasting blood glucose (FBG), tissue glycogen, glycosylated haemoglobin, plasma concentrations of insulin and GLP-1 hormone (glucagon-like peptide 1) in healthy and diabetic wistar rats.MethodsMale Wistar rats (both normal and diabetic) were treated with AEMC by gavaging (300 mg/kg body wt/day for 28 days).ResultsAEMC was found to increase tissue glycogen, serum insulin and GLP-1 non-significantly (P > 0.05) in normal, significantly (P < 0.01) in diabetic Wistar rats, whereas decrease in FBG and Glycosylated haemoglobin non-significantly (P > 0.05) in normal, significantly (P < 0.01) in diabetic Wistar rats. The elevation of GLP-1 level in normal and diabetic treated groups may be due to the L-cell regeneration and proliferation by binding with L-cell receptors and makes a conformational change, resulting in the activation of a series of signal transducers. The polar molecules of M. charantia also depolarize the L-cell through elevation of intracellular Ca2+ concentration and which in turn releases GLP-1. GLP-1 in turn elevates beta-cell proliferation and insulin secretion.ConclusionThe findings tend to provide a possible explanation for the hypoglycemic action of M. charantia fruit extracts as alternative nutritional therapy in the management and treatment of diabetes.

Modulation of Diabetes by Natural Products and Medicinal Plants via Incretins

“…Several metabolites, such as α-eleostearic acid or a Zn-free protein, and mechanisms have been described; however, the implication of GLP-1 was not analyzed. In this way, Bhat et al [75] recently studied the effect of an aqueous extract (300 mg/kg/d for 28 d) of bitter melon on both normal and diabetic Wistar rats, demonstrating that this extract increased insulinemia and GLP-1 in normal (nonsignificant) and in diabetic Wistar rats (significant, p < 0.01). This effect was associated to elevated β-cell proliferation and insulin secretion.…”

Hypoglycemic Effect of High-Resistant Starch Analog Rice Through GLP-1 and Insulin or High-Resistant Starch Analog Rice Attenuates Blood Glucose Level Through Enhancement of GLP-1 and Insulin

“…Correlation test showed a significant relationship between GLP-1 serum level with RS (0.736) and fiber (0.733). RS and fiber inhibit the digestion and absorption of food in the intestine and accelerating the onset of satiety [11,15,16]. This effect leads to the stimulation of L cells in the intestine to secrete GLP-1 [17].…”

“…That is because AR has higher levels of RS and fiber than rice, so AR can increase GLP-1 higher than rice. Furthermore, GLP-1 stimulates insulin secretion [15].…”

“…There are several possible mechanisms that correlate the increase in serum GLP-1 with insulin serum level, namely: (1) pancreatic β-cell protective or prevention of apoptosis [22] and proliferation pancreatic β-cells [15] so that the number of the cells increases; (2) stimulating GLUT-2 expression [23,24].…”

“…This proves that the stimulation effect on insulin secretion by GLP-1 was not through increased expression of GLUT-2 or an increase in the number of pancreatic β-cell. Hence, the effect of stimulation on insulin secretion by GLP-1 was likely through an increase in the number of receptors [15,23] or through other mechanisms such as stimulation on hexokinase activity [23].…”