effect of ganoderma lucidum hydroalcoholic extract on insulin release in rat-isolated pancreatic islets

objective: ganoderma lucidum (g. lucidum) has been suggested to increase serum insulin level.this study was undertaken to investigateits direct effect on the islets of langerhans. material and methods: male albino wistar rats were anesthetized and the islets were isolated after digestion of the pancreas with collagenase. the islets were incubated for 60 min in krebs bicarbonate buffer containing 3 or 10 mm glucose in the presence of hydroalcoholic extract of g. lucidum (1 mg/ml), 3-isobutyl-1-methylxanthine (ibmx, 100 µm) or vehicle. results: exposure of islets to the extract increased insulin secretion at basal (3 mm) glucose concentration. increase of glucose concentration to 10 mm resulted in a significant increase in the rate of insulin secretion. while the ibmx could augment insulin release evoked by 10 mm glucose, the extract failed to modify it. conclusion: our results demonstrate that g. lucidum acts directly on the langerhans islets to increase basal insulin release.