Momordica dioica Stimulated Insulin Secretion from Rat Pancreatic Islets is Independent of ATP-Sensitive K Channel

Antidiabetic and insulin secretagogues activity of Momordica dioica has been reported earlier. In the present work, the effect of Aqueous Extract of Momordica dioica (AEMD) was studied on insulin secretion with an evaluation of its mechanisms of action. Phytochemical analysis of AEMD was also carried out. AEMD showed the presence of alkaloids, saponins, flavonoids, tannins, and sugars. Isolated pancreatic islets of normal Wistar rats were incubated in HBBS buffer at 3.3 and 16.7mM glucose, 1 and 2mg/ml AEMD and 1mg/ml of nicorandil, alone and in combination. Release of insulin in external media was measured by ELISA. AEMD stimulated insulin release from the isolated islets at 3.3 and 16.7mM glucose. Insulin release was more pronounced at 2mg as compared to 1mg concentration. AEMD mediated enhancement in insulin secretion was not diminished by nicorandil, suggesting K-ATP channels independent mechanism. Cytotoxicity studies were carried out by trypan blue uptake and LDH release assay. Trypan blue gained access to 8.2±1.9% cells while 7.1± 1.4% dead islet cells were observed in LDH release assay on AEMD exposure, proving that the extract was non toxic at tested concentration. AEMD released insulin in a dose dependent manner and this induction was independent of K-ATP channels of β-cells.