Quercetin Enhances the Function and Reduces Apoptosis of Mouse Islets.

•Quercetin (QE) is an antioxidant, anti-inflammatory, flavonoid compound.•Treatment with QE enhanced glucose-induced insulin secretion.•The HO-1and Bcl-2 levels were significantly elevated in the QE-treated group.•QE treated islets attenuated expression of NO, iNOS, BAX, and apoptosis.•QE treatment enhanced islet function before transplant and attenuated cytokine–induced damage associated with NO production and apoptosis.