Ameliorative Effects And Mechanism Of Mulberry Leaves Extracts On Insulin Resistance Of HepG2Cell

Diabetes mellitus, kind of endocrine diseases affected by genetic and environmental, harmhuman health seriously. The clinical medicine therapy for diabetes have curative effect andlow toxic problems, by contrast, traditional Chinese medicine, easy to use for a long time, hashigher security. modern pharmacology studies show us that mulberry leaf, the traditionalChinese herbal medicine, has the efficacy peace, extensive use and little side effectsadvantages in the prevention and treatment on diabetes mellitus.The symtoms of Type2diabetes mellitus (T2DM) are mainly for insulin resistance orinsufficient insulin secretion. The liver, the main places for absorbing, storeing, synthesizing,metabolism of glucose, plays the most important and direct role in maintaining blood glucosestability. Therefore, the liver cells of sugar metabolism disorder to insulin resistance is veryimportant and significant. AMPK is a kind of important protein kinase, regulate the bodyenergy metabolization balance. In the liver, activation of AMPK can enhance glucose intake,the oxidation of fatty acid and insulin sensitivity, therefore, AMPK become a drug targets oftreatment for type2diabetesThis paper is aim to build the liver HepG2cell of insulin resistance model and to study howmulberry leaves extracts(MLE), mulberry leaf polysaccharides (MLP) and mulberryleaves, with rosiglitazone for positive control medicine, with AMPK for targets, improvefunction of liver insulin resistance and its molecular mechanism. It is mainly studied that howthey regulate the metabolism of glucose and promote absorption of glycogen glucose.Specific content is as follows:（1）Establishing the liver HepG2cell of insulin resistance model and stability studies:Insulin resistant of HepG2cell model was induced by high concentration of insulin. Theconditions of the effect time and the effect insulin are optimized and the stability is tested.The best solutions is in the concentration of10μ g/ml insulin for48hours, HepG2cells wereresistant to insulin and the insulin resistance was maintained for48hours.（2）Effect of bioactive components in mulberry leaves on glucose consumption in insulinresistance of HepG2: Iinsulin resistant models of HepG2were induced by high concentrationof insulin for36h. The glucose consumption of cellswere detected after incubation withbioactive components in mulberry leaves. Results show that mulberry leaves extracts,mulberry leaves flavonoids and mulberry leaf polysaccharides advanced glucose uptake ininsulin-resistant HepG2cells (P<0.05) compared with model group.Mulberry leaves extracts and mulberry leaves flavonoids have no significant difference compared with the normalgroup (P>0.05), indicating that cells can be returned to normal after incubation with mulberryleaves extracts and mulberry leaves flavonoids; Without insulin, mulberry leaves extracts,mulberry leaves flavonoids and mulberry leaf polysaccharides can also advance glucoseuptake in the insulin resistance of HepG2cells,which concludes that the mechanism may beirrelevant with insulin.（3）The molecular mechanism of glucose uptake in insulin-resistant HepG2cellsincubation with bioactive components in mulberry leaves: The expression andphosphorylation of AMPKα、 Akt were determined with by western blotting (P>0.05).Mulberry leaves extracts enhance phosphorylation of AMPK(P<0.05). Mulberry leavespolysaccharides、mulberry leaves flavonoids、 mulberry leaves extracts do not change thephosphorylation status of AKT(P>0.05). Therefore, the mechanism of mulberry leavesextracts on glucose uptake is the regulation of AMPK α phosphorylation, independent oninsulin.（4）Effect of bioactive components in mulberry leaves on glucose metabolism ininsulin-resistant HepG2cells: The activities of hexokinase, pyruvate kinase and the content ofthe liver glycogen were detected by hexokinase assay kit, pyruvate kinase assay kit and theway of anthrone respectively. It is suggested that mulberry leaves extracts have the effects ofimproving HK and PK vitality to promote blood glucose to enter the liver cells and glycogensynthesis. Mulberry leaves extracts can regulate the glucose metabolism and improve thesymptoms in insulin-resistant HepG2cells.It is further confirmed that mulberry leaf has high application value as oralglucose-lowering drugs, the paper provides experiment basis and theoretical foundation forthe research and development of effective parts in mulberry leaves; At the same time, theresearch provides the new ideas and methods of drug screening for the treatment of type2diabetes and other metabolic syndrome diseases, especially for the development of traditionalChinese medicine drugs of insulin resistance. It has certain directive significance for relativedrug development.