Study On The Uric Acid-Lowering Activity And Mechanism Of Baicalein Based On GLUT9

BackgroundHyperuricemia has become the "fourth highest" that bothers modern people.Hyperuricemia is a basic metabolic disease.The main mechanism is excessive uric acid production and reduced uric acid excretion.In clinically,90%of hyperuricemia patients have hyperuricemia caused by reduced excretion.Uric acid in the human body is mainly excreted in urine through the kidneys.URAT1 is a hot spot in the research and development of uric acid excretion drugs in recent years.GLUT9,as another key site in excretion,has broad research prospects.The research and screening of the compound platform targeting GLUT9 and the mechanism of action of the drug may have great research value in promoting uric acid excretion.This article will explore the uric acid-lowering activity of baicalein in vivo and in vitro and its mechanism.ObjectiveThe aim is to study the inhibitory activity of baicalein on GLUT9 and URAT1 in vitro,the mechanism of action in vitro and its uric acid-lowering activity and mechanism in hyperuricemia mice,and to further design and develop GLUT9-targeted uric acid excretion drugs Provide method support and theoretical basis.Method1)The mGLUT9a plasmid and eGFP were co-transfected into HEK-293T cells,and the methodological establishment of in vitro screening and inhibiting the biological activity of GLUT9 was explored;2)Use the in vitro screening model to screen out flavonoids that inhibit the biological activity of GLUT9 and URAT1 at the same time and have good activity;3)Determine the mechanism of baicalein in vivo and in vitro by qRT-PCR,Western blot,electrophysiology,isotope tracing,immunofluorescence,etc.Result1)Successfully established and optimized an electrophysiological cell model that expresses mGLUT9a heterologously through HEK-293T cells;verified the overexpression of GLUT9 on the cell model by Western blot and qRT-PCR;verified the uric acid transport kinetics shown by the cell model by electrophysiology Substrate specificity,voltage dependence,potassium ion dependence,PH dependence,typical inhibitory effects of positive drugs,and molecular mechanisms of action of some drugs.2)The electrophysiological model and the isotope uric acid uptake experiment were used to screen drugs that have inhibitory effects on GLUT9 and URAT1.It was found that baicalein can inhibit GLUT9 with IC50 values of 30.17±8.68μM and 31.56±1.37.M respectively through non-competitive inhibition and URAT1.3)Establishing a mouse model of hyperuricemia,and exploring and discovering that baicalein has no significant difference in body weight,kidney-to-body ratio,liver-to-body ratio,etc.;baicalein at doses of 100 mg/kg-200 mg/kg can reduce serum Creatinine and urea nitrogen levels;reduce the activity of xanthine oxidase(XOD)in the serum and liver of hyperuric acid mice,and reduce the production of uric acid;it can reduce the serum uric acid level and the expression of mURAT1 and mGLUT9 mRNA and protein in the kidney in a dose-dependent manner;Increasing the amount of excreted urine and the content of uric acid in the urine may be through direct action on Akt/GSK-3β pathway and indirect inhibition of insulin to act on Akt/GSK-3β to reduce uric acid reabsorption and promote uric acid excretion from urine.And the effect is equivalent to AP(10 mg/kg).ConclusionBaicalein has the physiological activity of lowering uric acid,and in vitro experiments show that the relative inhibitory activity of baicalein on GLUT9 and URAT1 is equivalent to that of BM,and stronger than probenecid;in vivo experiments,BAL can effectively reduce uric acid by inhibiting the activity of XOD enzyme The production and promotion of hyperuricemia mice enhance the excretion of urine uric acid,reduce the serum uric acid level,the activity in the body is equivalent to allopurinol,its mechanism of action on GLUT9 may be related to Akt/GSK-3β pathway.