Oral ingestion of Shiikuwasha extract suppresses diabetes progression in mice by preserving β-cell mass.

Introduction: Nobiletin is a polymethoxyflavonoid abundant in citrus peels and has been reported to have various bioactive effects. We have previously reported that nobiletin inhibits endoplasmic reticulum stress-induced apoptosis in the pancreatic β-cell line INS-1 and that continuous subcutaneous administration of nobiletin suppresses the progression of diabetes by protecting β-cells in type 2 diabetic mice. In the present study, we investigated effects of oral ingestion of Shiikuwasha extract rich in nobiletin on the pathogenesis of type 2 diabetes in mice.