Research On The Mechanism Of Chicory For Lowering Uric Acid Based On Renal Excretion

Background:Hyperuricemia is one of the metabolic disease which closely related with diabetes,hypertension,insulin resistance,obesity and other diseases.It results from the underexcretion of uric acid in the vast majority of cases（90%）,overproduction of uric acid,or a combination of the Two.Anyway it is pathologic phenomenon that shows supersaturation state of urate in blood.Recent studies also support the view that hyperuricemia is a risk factor for renal and cardiovascular diseases.The recent epidemiological investigation showed hyperuricemia has a high prevalence and incidence.The pathogenesis of hyperuricemia are necessarily bound up with lifestyle,dietary modifications,gene mutations and so on.Western medicineas drugs be used to correct hyperuricemia appears to play a dominate role,while vast majority could lead to severe adverse reactions.Observing the therapeutic effect of traditional Chinese medicine and investigating its mechanism on hyperuricemia would be of great academic and clinical interest.Uric acid is produced primarily in the liver by xanthine oxidase,and two thirds excreted via the kidneys with the remaining one third excreted into the gut and biliary passage.Genomics studies and genomewide association studies have revealed the critical effect of transporters of urate for urate excretion.Recently,several study functionally characterized the facilitatory glucose transporter family member SLC2A9（GLUT9）,human organic anion transporter-SLC22A6（OAT1）,SLC22A8（OAT3）are candidate genes for urate handling.GLUT9 expressed mainly in the liver and kidney,which have effect on both synthesis and secretion of uric acid.OAT1 and OAT3 mainly expressed in the kidney and be in charge of urate excretion.Chicory is well known in Uighur folk medicine as a cholagogic and diuretic agent to improve the appetite,to increase digestion and to cure liver diseases,etc.The has effect on lowering the level of blood glucose,blood lipid and uric acid.Improving immune function and regulate intestinal flora of chicory has been proved by modern research.In the past decades,our research teamgroup made research comprehensively through identification of origin chemical composition,preparation,pharmacology,pharmacodynamics,toxicology of chicory.The purpose of this experiment is to explore the pharmacological mechanism of Cichory on hyperuricemia from the perspective of urate transporters.Put forward the following hypothesis:GLUT9,OAT1,OAT3 expression abnormally in the kidney is one of the causes of Hyperuricemia,induced by high fructose and high purine diet induced hyperuricemia.Chicory correct hyperuricemia through the mediation on GLUT9,OAT1,OAT3.Objectives:First,to explict the changes of renal uric acid excretion of the two model animal,rat and quail,illustrate the change of the expression of hyperuricemia rat renal transporters GLUT9,OAT1.Further more,to Explict the changes of hyperuricemia quail renal transporters OAT1-LIKE,OAT3-LIKE,Lay the foundation for subsequent pharmacologicalmechanism study of Chicory.Second,to analysis of the pharmacological function of traditional Chinese medicine（TCM）chicory on hyperuricemia quail and rat,explicting that the influence of chicory on rat kidney urate excretion and the regulation effects on renal urate transportersGLUT9,OAT1,OAT1-LIKE,OAT3–LIKE,to reveal the pharmacological mechanism of Chicory from the perspective of renal urate excretion.Research contents and methodsThis paper consists of two parts,literature review and experimental research.Literature review mainly gather the etiology of hyperuricemia home and abroad in recent more than 10 years,Colleting the current situation of glucose metabolic,purine metabolic,urate excretion,the drug increasing uric acid excretion.The experimental research part uncover the change of renal rat renal transporters GLUT9,OAT1and the quail renal transporters OAT1-LIKE,OAT3–LIKE,adoptingthe methods of biochemistry,animal pathology,and molecular biology technique.Explicit the mechanism of Chicory from the perspective of renal urate excretion.Experimental study section is divided into two chapters:The first chapter:the effect of chicory on hyperuricemia rat renal transporters GLUT9 and OAT1.Firstly,copy the hyperuricemia rat modle;detect the serum uric acid level on the whole animal level,observe the rat renal excretion and the related excretion indicators;observed the rat kidney tissue pathology on the tissue level;Using immunohistochemical（IHC）method detect the expression of kidney transporter GLUT9,OAT1.Secondly,observing the effect of chicory on the serum uric acid level,on the renal uric acid excretion,on the expression of rat kidney transporter GLUT9 and OAT1.To clarify the effect of chicory on the hyperuricemia rat.The second chapter:the influence of chicory on renal transporter OAT1-LIKE,OAT3-LIKE’s expression of the hyperuricemia quailCopy the hyperuricemia quail model;Then observe the urate level changes of quail faeces and;Determine the quail renal transporters OAT1-LIKE,OAT3-LIKE expression level.On the basis of animal pathology model,expand the study of chicory efficacy.Observe the effect of chicory to the quail blood uric acid level and the expression level of quail kidney OAT1-LIKE,OAT3-LIKE;illustrating the efficacy mechanism of chicory extract lowering the serum uric acid.Results（1）Research on Changes of rat renal urate excretion and kidney transporter GLUT9,OAT1:excessive fructose can make the rat hyperuricemia model,accompany with the rise of serum glucose,serum triglyceride.At the 28d,42d,the clearance rate of creatinine（CCR）decreased,and at the 42d,the clearance rate of uric acid（CUA）decreased,which indicate that the renal function of rat decrease.Kidney tissue pathological slices show that the glomerulus and tubuler is normal.There are no difference between the two control group and the model group,no foreign deposition is found.At the 56d,the expression of GLUT9 increased and the OAT1decreased.Therefore,the pathology mechanism may be related with the decreasing of rat renal urate excretion,the upregulation of rat renal transporter GLUT9 and the downregulation of the OAT1.（2）Research on Changes of quail renal urate excretion and kidney transporter OAT1-LIKE,OAT3-LIKE:continuous high purine diet can induce hyperuricemia quail model.Just the beginning of the model formation,the quail urateexcretion of the model goup increased,with the passage of time,and it decreased comparing to the control group.At the35^th day,the expression of renal transporter OAT1-LIKE,OAT3–LIKE increased.The quail hyperuricemia pathology mechanism may be related with the decreased exrpression of quail renal OAT1-LIKE,OAT3–LIKE.（3）Chicory effect on the rat renal urate excretion and kidney transporter GLUT9,OAT1:chicory have an effect on reducing the serum uric acid concentration,improving the CCR,CUA,and protecting the kidney fuction to some extend,which is similar to benzbromarone.Meanwhile,chicory can downregulate the expression of rat renal transporter GLUT9 and upregulate the expression of rat renal transporter OAT1.These can be one mechanism of chichory lowring the serum uri acid.（4）Chicory effect on the quail renal urate excretion and kidney transporter OAT1-LIKE,OAT3-LIKE:chicory can prevent and quail hyperuricemia.The result show that chicory can lowering the serum uric acid concentration,upregulate the expression of rat renal transporter OAT1-LIKE mRNA,OAT3-LIKE mRNA.These canbe a mechanism of chichory to preventing the formation of hyperuricemia.ConclusionsThe research on the experiment verify the hypothesis,perfect and correct hypothesis of the contents,summarizing the following conclusions:1.Continuous high fructose drinkng water or high purine-diet can induce the hyperuricemia.The pathology mechanism can be the fructose/purine rise the serum uric acid firstly,and then lead to the renal dysfunction,in turn,the renal dysfunction further cause the persistent high serum uric acid level.2.High fructose drikng water or high purine-diet cause the renal excretion decrease,manifest the renal function decrease.HE staining show that the glomerulus and tubuler is normal.There are no difference between the two control group and the model group,no foreign deposition is found.That imply the decreased urate is the result of the decrease of kidney function instead of kidney itself damage.3.The hyperuricemia rat kidney expression of GLUT9 increased and the OAT1decreased.The hyperuricemia quail kidney expression of OAT1-LIKE mRNA,OAT3-LIKE mRNA decreased.These maybe pathology mechanism of the two Hyperuricemia model.4.The effect of chichory preventing hyperuricemia may be associated with increasing the renal urate secretion,decreasing the renal reabsorption of urate.The effect can be attribute to its downregulation to GLUT9 and upregulation to OAT1,OAT1-LIKE,OAT3-LIKE.Innovation points1.From the perspective of renal urate excretion,explicit the change of hyperuricemia rat renal transporter GLUT9,OAT1 is one of the mechanism of the pathologies for high fructose-induced hyperuricemia rat model..2.This research explicit that the decreasing expression of quail renal transporter OAT1-LIKE,OAT3-LIKE canbe one of the mechanism of high purine-induced hyperuricemia model for the first time.3.For the first time to clarify the chichory pharmacodynamical mechanism from the perspective of renal urate excretion,and explicit its effect on lowing the expression of renal transporter protein GLUT9,increasing the expression of OAT1,OAT1-LIKE mRNA,OAT3-LIKE mRNA.