The Effect And Mechanism Of Polydatin On Acute Gouty Arthritis

Objective:Based on the mouse model of acute gouty arthritis induced by injection of sodium urate（MSU）crystals into the ankle joint,the therapeutic effect of polydatin on acute gouty arthritis was evaluated,and its mechanism was explored by detecting its effect on inflammatory and oxidative stress-related signal pathway.Method:1.Evaluation of polydatin on inflammatory response and oxidative stress in acute gouty arthritisThe mice model of acute gouty arthritis was induced by injection of MSU crystals into the ankle joint,and then three doses of polydatin were used to interfere with the model mice.The degree of ankle swelling,gait and histopathology of ankle joint were observed.The content of pro-inflammatory factors and m RNA expression in ankle joint,as well as the contents of oxidative stress products NO,MDA and antioxidant GSH were detected to evaluate the anti-inflammatory and oxidative stress effects of polydatin on acute gouty arthritis.2.Mechanism and experimental verification of polydatin in treatment of acute gouty arthritis based on network pharmacologyThe potential targets of polydatin were predicted by Pharm Mapper platform,and then the protein names were standardized by Uni Prot database,and the disease targets related to acute gouty arthritis were collected through multiple disease databases.The potential targets of polydatin against acute gouty arthritis were obtained by intersection of both targets,then protein-protein interaction（PPI）network analysis,Gene Ontology（GO）function analysis and Kyoto Encyclopedia of Genes and Genomes（KEGG）pathway enrichment analysis were performed for potential targets.Based on the mechanism prediction of network pharmacology,the experimental verification is carried out at the animal level.We explore the effect of polydatin on targets m RNA and protein expression by RT-q PCR and immunohistochemical.3.Study on the mechanism of polydatin against oxidative stress in acute gouty arthritisThe effects of polydatin on the content of free iron,the m RNA and protein expression of ferritin and the m RNA expression of gp91^phox,Nrf2and HO-1 in the ankle joint of model mice were detected by kit,RT-q PCR method and immunohistochemistry.Result:1.Evaluation of polydatin against inflammatory response and oxidative stress in acute gouty arthritis（1）Polydatin could significantly improve ankle swelling in a dose-dependent manner within 12 hours of the most severe attack of acute gouty arthritis.（2）Polydatin improved gait abnormality in mice with acute gouty arthritis in a dose-dependent manner.（3）Polydatin could significantly improve the inflammatory cell infiltration and synovial edema and proliferation of joints caused by MSU crystals.（4）Polydatin could inhibit the transcription and production of pro-inflammatory factors induced by MSU in a dose-dependent manner and promote the transcription of anti-inflammatory factors.（5）Polydatin could inhibit the production of oxidative stress products NO and MDA induced by MSU crystals,promote the production of antioxidant GSH,and significantly reduce the oxidative stress damage induced by MSU crystals.2.Mechanism and experimental verification of polydatin in treatment of acute gouty arthritis based on network pharmacology（1）Two hundred and thirty potential targets of polydatin were predicted and 811 disease targets of acute gouty arthritis were collected.The two targets were intersected to obtain 31 common targets of polydatin and acute gouty arthritis.PPI network analysis showed that MMP9,HSP90,MAPK14,IL2,PPAR-γ,SRC and IGF1 were the key targets of polydatin against acute gouty arthritis.GO function and KEGG pathway enrichment analysis showed that the related pathways were mainly inflammatory and immunomodulatory pathways.The most significant result of KEGG enrichment was PPAR signal pathway.（2）Animal level verification experiment confirmed that polydatin could promote the transcriptional expression and protein production of PPAR-γin the ankle of mice with acute gouty arthritis,and then inhibit the expression of NLRP3,ASC,pro-caspase-1?m RNA related to NLRP3inflammatory bodies and the production of NLRP3 protein in the ankle joint of mice with acute gouty arthritis.3.Study on the mechanism of polydatin against oxidative stress in acute gouty arthritis（1）polydatin could activate the expression of ferritin m RNA and protein in the joint tissue of acute gouty arthritis mice,thus reducing the content of free iron in the ankle joint of acute gouty arthritis mice.（2）Polydatin significantly inhibited the m RNA expression of gp91^phox in ankle joint of mice with acute gouty arthritis.（3）Polydatin significantly inhibited the expression of Nrf2 and HO-1 m RNA in ankle joint of mice with acute gouty arthritis.Conclusion:1.Polydatin could significantly inhibit the inflammatory response of acute gouty arthritis induced by MSU crystals in a dose-dependent manner and reduce the damage of oxidative stress.2.Network pharmacology predicted that PPAR signaling pathway and PPAR-γtarget were most closely related to the mechanism of polydatin against acute gouty arthritis.Animal experiments had verified this prediction.3.Polydatin may play the role of antioxidant stress in three ways:reducing the content of free iron ion in the ankle joint,inhibiting the m RNA expression of gp91^phox,and activating the m RNA expression of Nrf2 and HO-1.