It has been suggested that resveratrol has antioxidative, anti-inflammatory, and anticancer activities. Many studies imply the potential effects of resveratrol in diabetes treatment. The purpose of this study was to examine the effects of resveratrol on pancreatic beta-cells. INS-1 (832/13) cells were cultured in the presence of resveratrol with or without high concentration of glucose. Resveratrol at various low concentrations (5uM~0.5uM) did not alter glucose toxicity. Resveratrol at 50uM cultured with 25mM glucose medium increased apoptotic cells and reduced viable cells. There was an about 4.7-fold increase in apoptotic cells and 29% less in viable cells. For glucose-stimulated insulin secretion (GSIS), basal insulin was significantly higher in resveratrol treated groups compared to that of control from samples cultured at 11.1mM glucose (50uM: 4.5-fold increase; 3uM or 1uM: 1.3 fold increase). While culturing at high glucose suppressed GSIS, resveratrol (3uM or 1uM) partially restored GSIS. Resveratrol at 50uM caused a much higher basal insulin secretion with no further GSIS effect. In conclusion, resveratrol at low concentrations do not protect pancreatic beta-cells from glucose induced toxicity, but it may partially preserve the function of insulin secretion. While resveratrol at high concentration induces basal and stimulated insulin secretion, it may cause significant cell apoptosis.
