Berberine, an isoquinoline alkaloid, inhibits streptozotocin-induced apoptosis in mouse pancreatic islets through down-regulating Bax/Bcl-2 gene expression ratio

► This study established in vitro experimental models using STZ-treated islet cells. ► The protective mechanism of berberine on STZ-treated islets was determined. ► The Bax/Bcl-2 genes expression in the islets was assayed using real-time qPCR. ► Berberine showed an anti-apoptotic effect on STZ-treated islets. ► Berberine decreased the Bax/Bcl-2 genes expression ratio in STZ-treated islets.