Effect of alogliptin, pioglitazone and glargine on pancreatic β-cells in diabetic db/db mice

► Protective effects of pioglitazone (thiazolidine derivatives), alogliptin (dipeptidyl peptidase 4 inhibitor) and insulin on β-cell in diabetic db/db mice. ► Islet mass and insulin content were preserved in pioglitazone, pioglitazone + alogliptin or insulin groups. ► Pioglitazone + alogliptin and insulin preserved normal insulin secretion, although pioglitazone mono therapy improved partially. ► Expression level of MafA and GLP-1R was preserved by pioglitazone or insulin therapy.