The Protective Effect And Mechanism Of Arctigenin On Toxoplasma Gondii Infection-induced Liver Injury

Objective:To investigate the protective effect of arctigenin(AG)on liver injury induced by Toxoplasma gondii(T.gondii)infection and its mechanism based on High Mobility Group Protein B1(HMGB1)/Toll-like receptor 4(TLR4)/Nuclear factor-κB(NF-κB)signaling pathway.Methods:In vitro experiment,Mouse normal liver cell line NCTC-1469 was infected with T.gondii virulent strain RH to established hepatocyte injury model.Treated with AG(5,10 and 20μM)and sulfadiazine(100μg/m L)for 36 h after 4 h of infection,respectively,cell supernatant and precipitate were collected.In vivo experiment,female BALB/c mice were injected with 1×10~3 T.gondii virulent strain RH tachyzoites by intraperitoneally to establish a model of acute toxoplasma infection.Four hours after infection,the mice were orally administered with AG(25,50 or 100 mg/kg)or SD-Na(100 mg/kg)for 6 days.The mice were dissected and the serum and liver tissues were separated.The survival rate of host cells was detected by trypan blue staining.The contents of alanine aminotransferase(ALT)and aspartate aminotransferase(AST)in cell supernatant and serum of mice were determined by ELISA.The number of T.gondii and the expression of related inflammatory molecules were observed by immunofluorescence staining.The pathological injury of liver cells and liver tissue was observed by hematoxylin eosin staining.Western blotting was used to detect the expression of TLR4/NF-κB signal pathway and related proteins.Results:AG effectively improves the survival rate of T.gondii-infected NCTC-1469cells,and inhibits the proliferation of T.gondii in NCTC-1469 cells,and AG reduces the content of transaminase in the supernatant of NCTC-1469 cells and the serum of mice in a dose dependent manner,and improves the pathological damage of liver cells and liver.In addition,AG significantly inhibits the overexpression of HMGB1 and induced nitric oxide synthase(i NOS)in NCTC-1469 cells and mouse liver tissue infected with T.gondii,and prevent the extracellular release of HMGB1.AG down-regulate the expression of TLR4/NF-κB signaling pathway related proteins(TLR4、My D88、p-NF-κB p65、NF-κB p65、p-IκBα、IκBα)and inhibits the nuclear translocation of NF-κB p65 in NCTC-1469 cells and liver tissues infected with T.gondii.Conclusion:AG has a good anti-T.gondii activity,and inhibits the excessive production of inflammatory mediators by interfering with the activation of TLR4/NF-κB signaling pathway,so as to improve the liver injury caused by T.gondii infection.