Abstract: To observe the protective effect of Potentilla discolor aqueous extract for type 2 diabetic rats islet.Type 2 diabetes rat model was induced by fat emulsion formulation and small dose of streptozocin.Biochemical assay was applied to measure serum glucose,total cholesterol (TC) ,high density lipoprotein (HDL),low density lipoprotein (LDL) and triglycerides (TG).ELISA was applied to measure serum insulin levels.Pancreatic histology was examined by HE staining.Immunohistochemistry (IHC) was employed to examine Forkhead box O 1 (FoxO1),p-FoxO1 and insulin protein expression. P.discolor aqueous extract groups significantly decreased random blood glucose and TC levels,increased insulin expression,promoted the release of insulin,decreased the expression of FoxO1 protein in the nucleus,induced the phosphorylation of FoxO1 protein and its getting out of the nucleus. P.discolor aqueous extract played a protective role for type 2 diabetic rats islet cell.The mechanism may be related to decrease FoxO1 expression and increase p-FoxO1,which further increase the number and improve the function of β-cells.

Key words: pancreas, Potentilla discolor aqueous extract, type 2 diabetic, protective effect, FoxO1