Korean red ginseng stimulates insulin release from isolated rat pancreatic islets

Ethnopharmacological relevanceKorean red ginseng (KRG), one of heat-processed Korean ginseng (Panax ginseng C.A. Meyer), has a long history as herbal remedy for antidiabetic effect.Aim of the studyThe effect and mechanism of KRG on stimulation of insulin release were investigated in isolated rat pancreatic islets.Material and methodsPancreatic islets isolated from rats were used to evaluate the insulinotropic action of KRG. The effect of Ca on the insulinotropic action of KRG was investigated.ResultsThe aqueous ethanolic extract of KRG (AEE-KRG) (0.1–1.0 mg/ml) significantly evoked a stimulation of insulin release at 3.3 mM glucose compared to the control. Experiments at different glucose concentrations (8.4 and 16.7 mM) showed that AEE-KRG significantly stimulated on its own whereas it did not potentiate insulin secretion induced by glucose. The extracellular Ca2+-free condition, a L-type Ca2+ channel blocker and an ATP-sensitive K+ channel opener significantly inhibited insulin secretion evoked by AEE-KRG.ConclusionThese findings suggest that KRG displays beneficial effects in the treatment of diabetes at least in part via the stimulation of insulin release in a glucose-independent manner.