Hypoglycaemic and hypolipidemic effects of unripe apple extract in a murine diabetic model

Abstract

The increasing incidence of diabetes is a global concern. Current treatment modalities involving lifestyle modifications and pharmacotherapy are not effective in 50% of patients. Unripe apples contain polyphenols which are known to have antidiabetic effects. To verify the effects of unripe apple extract (UAE), the antioxidant activity of UAE was confirmed using a cell-free DPPH assay; and nitric oxide production and cytotoxicity were investigated in RIN-m5F cells. Biochemical analysis, oral glucose tolerance test, and histological analyses of the pancreas and liver were also conducted. UAE treatment induced hypoglycaemic conditions in alloxan-induced RIN-m5F cells. Further, UAE treatment showed antidiabetic effects in db/db mice by reducing plasma glucose and fructosamine levels without affecting the food intake and body weight. Additionally, UAE improved glucose tolerance and lipid parameters, and restored the pancreatic tissue in db/db mice. These results demonstrated the antidiabetic effects of UAE on alloxan-treated pancreatic islet-derived cells and in db/db mice, and suggested that UAE can be potentially used as a medicine and dietary supplement or functional food in antidiabetic therapy.