The Hypoglycemic Effect Of Cortex Mori Extract On Insulin-Resistance Experimental Models

Objective:Insulin resistance (IR) is the basis of pathophysiological mechanism in the natural history of type2diabetes, Cortex Mori is a Traditional Chinese medicine drug and has being commonly used to treat type2diabetes. In this thesis,we studied the effect of Cortex Mori extract on decreasing Glucose and mechanisms of its action on insulin resistance, in cell and animal models, by the means of cell biology and modern pharmacological methods.Methods:In vitro:the insulin-resistance model of HepG2cell was established by inducing cell with high concentration insulin. The glucose consumption in cell culture was determined by glucose oxidase-peroxydase (GOD-POD) method and the proliferation of HepG2cell was detected by MTT method after Cortex Mori extract treatment; In vivo:Diabetic mouse was induced by combined use of high fat-glucose diets and low dose streptozotocin (STZ). The oral glucose tolerance test (OGTT) was performed after2weeks of Cortex Mori extract administration. The effects of Cortex Mori extract on glucose or lipid metabolism and insulin resistance index(HOMA-IR) were investigated with these models.Results:In the concentration of10-6mol/L insulin for48h, HepG2cells were resi-stant to insulin and the insulin resistance model was maintained for72h without c-hange of cell functional change; Cortex Mori extract(20μg/ml、10μg/ml、5μg/ml) can promote the glucose consumption in insulin resistance of HepG2cell,and imp-roved the sensitivity of insulin resistance of HepG2cell to insulin, but it has no pr-oliferational effect on cell within test dose; The insulin resistance model of mouse was successfully established in vivo by combined use of high fat-glucose diets and low dose STZ; Cortex Mori extract(1.2g/kg、0.6g/k、0.3g/kg) obviously depress-ed fasting blood glucose of type2diabetes mouse, but there is no influence on no-rmal; Cortex Mori extract can improve glucose tolerance of type2diabetes mouse; Cortex Mori extract(1.2g/kg、0.6g/kg) can obviously regulate down fasting blood lipid of these mice; Cortex Mori extract can depress insulin and HOMA-IR.Conclution:Cortex Mori extract can promote the glucose consumption of the insulin-resistance model of HepG2cell, and obviously depresses fasting blood glucose、lipid and insulin, decreases insulin resistance index of type2diabetes mouse. The mechanism is to improve insulin resistance.