Taxifolin Blocks Monosodium Urate Crystal-Induced Gouty Inflammation By Regulating Phagocytosis And Autophagy

Objective: Taxifolin(TAX)is a flavonoid found in Pinus sylvestris and other pine plants,with pharmacological effects such as anti-inflammatory and antioxidant.In this study,we investigated the therapeutic effects of TAX on acute gout induced by Monosodium urate crystals(MSU)by establishing an in vivo,in vitro acute gout model.Methods: In vivo experiments,(a)In the MSU crystal-induced mouse air pouch model,male Kunming mice were randomly divided into the following five groups(n=5): including the normal group,MSU model group(3 mg/m L),TAX group(100mg/kg,200 mg/kg)and colchicine positive control group(3 mg/kg).Back skin tissues were fixed into 10% neutral buffered formalin solution for fixation and histological analysis,and the rest tissues were stored at-80℃ until analyzed.The expression levels of IL-1β,HMGB1,Caspase-1 and other related inflammatory factors in the back skin tissues were analyzed using Western blotting.(b)In the MSU crystal-induced acute gout model in mice,mice were randomly divided into 7 groups(n=5): the normal group,MSU model group(4 mg/0.1 m L),TAX administration group(50 mg/kg,100 mg/kg,200 mg/kg),TAX(200 mg/kg)administration alone group and colchicine positive control group(3 mg/kg).(c)Hyperuricemia model,the mice were randomly divided into 6 groups(n=5): the normal group,OXO plus yeast extract powder group(300mg/kg,body weight),OXO plus yeast extract powder plus TAX groups(100 or 200mg/kg,body weight),TAX alone administration group(200 mg/kg,body weight)and OXO plus yeast extract powder plus allopurinol group(7 mg/kg,body weight).In vitro,TAX was treated at 0-200 μM for 24 h,the effect of TAX on the survival rate of murine peritoneal macrophages by MTT assay.Pretreated with different concentrations of TAX(50,100,200 μM),incubated with LPS after 1 h,finally incubated with MSU crystals(500 μg/m L)for 18 h.Total cell protein was extracted and the cell supernatant was collected to detect the expression levels of IL-1β,HMGB1,caspase-1 and other related inflammatory factors in MPM.Results: In vivo,TAX ameliorated the pathological changes of paws,back skin and kidney and improved the swelling of mouse paws as observed by H&E staining,immunofluorescence and immunohistochemical staining.Meanwhile,TAX also reduced the expression of IL-1β,HMGB1,NE,caspase-1 and increased the level of LC3 expression,indicating that TAX can reduce the inflammatory response and induce the development of autophagy.In vitro,MTT assay results showed that TAX at 0-200 μM had no significant effect on MPM survival rate.LPS/MSU-stimulated MPM induced the development of inflammatory responses,while TAX pretreatment significantly reduced the release of IL-1β,caspase-1 and HMGB1,Cathepsin B and other related inflammatory factors.It also reduced the expression of Beclin-1 and SQSTM1 and increased the expression of LC3,promoted the autophagy and phagocytic capacity of MPM.Conclusion: This study showed that Taxifolin attenuated the inflammatory response in MSU-induced acute gout model by reducing the production of proinflammatory cytokines and promoting autophagy.Dietary supplementation with Taxifolin induced autophagy and attenuated the inflammatory response,thereby modulating acute gout.A preventive strategy combining dietary intervention with Taxifolin may provide a potential therapeutic option for pharmacological treatment to reduce the occurrence of gout.