Oleanolic acid enhances insulin secretion in pancreatic beta-cells.
We investigated the effect of oleanolic acid, a plant-derived triterpenoid, on insulin secretion and content in pancreatic beta-cells and rat islets. Oleanolic acid significantly enhanced insulin secretion at basal and stimulatory glucose concentrations in INS-1 832/13 cells and enhanced acute glucose-stimulated insulin secretion in isolated rat islets. In the cell line the effects of oleanolic acid on insulin secretion were comparable to that of the sulfonylurea tolbutamide at basal glucose levels and with the incretin mimetic Exendin-4 under glucose-stimulated conditions, yet neither Ca(2+) nor cAMP rose in response to oleanolic acid. Chronic treatment with oleanolic acid increased total cellular insulin protein and mRNA levels. These effects may contribute to the anti-diabetic properties of this natural product.
Teodoro
Tracy
T
Toronto General Research Institute, University Health Network, Toronto, ON, Canada M5G1L7.
Zhang
Liling
L
Alexander
Todd
T
Yue
Jessica
J
Vranic
Mladen
M
Volchuk
Allen
A
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009828:Oleanolic Acid / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D007328:Insulin; D009828:Oleanolic Acid; D002118:Calcium