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Investigation of morin‐induced insulin secretion in cultured pancreatic cells
Author(s) -
Lin Mang Hung,
Hsu ChiaChen,
Lin Jenshinn,
Cheng Juei Tang,
Wu Ming Chang
Publication year - 2017
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/1440-1681.12815
Subject(s) - morin , insulin , endocrinology , medicine , diazoxide , imidazoline receptor , secretion , chemistry , biology , pathology
Summary Morin is a flavonoid contained in guava that is known to reduce hyperglycemia in diabetes. Insulin secretion has been demonstrated to increase following the administration of morin. The present study is designed to investigate the potential mechanism(s) of morin‐induced insulin secretion in the MIN 6 cell line. First, we identified that morin induced a dose‐dependent increase in insulin secretion and intracellular calcium content in MIN 6 cells. Morin potentiated glucose‐stimulated insulin secretion ( GSIS ). Additionally, we used si RNA for the ablation of imidazoline receptor protein ( NISCH ) expression in MIN 6 cells. Interestingly, the effects of increased insulin secretion by morin and canavanine were markedly reduced in Si‐ NISCH cells. Moreover, we used KU 14R to block imidazoline I 3 receptor (I‐3R) that is known to enhance insulin release from the pancreatic β‐cells. Without influence on the basal insulin secretion, KU 14R dose‐dependently inhibited the increased insulin secretion induced by morin or efaroxan in MIN 6 cells. Additionally, effects of increased insulin secretion by morin or efaroxan were reduced by diazoxide at the dose sufficient to open K ATP channels and attenuated by nifedipine at the dose used to inhibit L‐type calcium channels. Otherwise, phospholipase C ( PLC ) is introduced to couple with imidazoline receptor (I‐R). The PLC inhibitor dose‐dependently inhibited the effects of morin in MIN 6 cells. Similar blockade was also observed in protein kinase C ( PKC ) inhibitor‐treated cells. Taken together, we found that morin increases insulin secretion via the activation of I‐R in pancreatic cells. Therefore, morin would be useful to develop in the research and treatment of diabetic disorders.