The Action Mechanism Of Several Kinds Of Plant Hypoglycemic Functional Components On GLTU4

As a kind of epidemic endocrine metabolic disease,the incidence of diabetes is increasing year by year,and new diabetics appear every time around the world.Diabetes can cause serious complications to the heart,brain,blood vessels,nerves,kidneys and skin.Diabetes,as a disease of high incidence,has become a serious damage to human life and health,and now diabetes treatments such as insulin and traditional hypoglycemic drug have a variety of side effects.So looking for a new fall blood sugar medicine has the very vital significance.Glucose transporter 4?GLUT4?is the only glucose transporter in response to insulin in adipocytes and muscle cells,and can be used as an important carrier of hypoglycemic drug targets.This thesis attempts to find new potential hypoglycemic drugs by targeting GLUT4.Lotus leaf,as a traditional Chinese herbal medicine,has long been used to treat diabetes.The alkaloids ingredient in the lotus leaves have also been confirmed to have hypoglycemic and hypolipidemic action.However,the specific active ingredients and the mechanism of the treatment of diabetes mellitus have not been elucidated.Therefore,in this paper,we studied the hypoglycemic activity of nuciferine and its effect on GLUT4 expression and translocation and attempted to further study its action mechanism.In this thesis,we first conducted experiments for nuciferine.We used cell glucose uptake assay kit to detect the effect of nuciferine on glucose uptake in L6 cells.Then,in the L6 cells stably expressing IRAP-mOrange,the translocation of GLUT4 and the changes of intracellular Ca²⁺levels were monitored by laser scanning confocal microscope.We used Western blotting to detect the effects of nuciferine on the level of GLUT4 expression in L6 cells.Our results show that nuciferine significantly increases glucose uptake and promotes the expression and translocation of GLUT4 in L6 cells.Nuciferine-induced GLUT4 translocation was inhibited by G?6983?PKC inhibitor?,Compound C?AMPK inhibitor?,PTX?G?protein inhibitor?,Gallein?G?/?protein inhibitor?,U73122?PLC inhibitor?.However,Wortmannin?PI3K inhibitor?,2-APB?IP₃R inhibitor?and BAPTA-AM(intracellular Ca²⁺chelator)could not inhibit nuciferine-induced GLUT4 translocation.In addition,nuciferine can increase PKC and AMPK phosphorylation in L6 cells.These results indicated that nuciferine promoted GLUT4 expression and translocation through the AMPK and G protein-PLC-PKC signaling pathway,thereby promoting glucose uptake of L6 cells.At the same time,the nuciferine promoted intracellular Ca²⁺increase in L6 cells by G protein-PLC-IP3R signaling pathway.Nuciferine-increased intracellular Ca²⁺was not involved in the process of GLUT4 expression and translocation,and may be associated with the fusion of GLUT4 and cell membrane.Our research suggests that nuciferine may develop into a new potential hypoglycemic drug.In addition,we also studied the effect of ergosterol from oyster mushroom and aloperine from sophora alopecuroide the level of GLUT4 expression in L6 cells,attempting to explore their potential in the treatment of diabetes.Our research show that the ergosterol promoted GLUT4 expression through the Akt and PKC signaling pathway and the aloperine can increase glucose uptake and promote the expression of GLUT4.