Research Of NLRP3 Inflammasomes Inhibiting Mechanism By Total Flavonoids From Litchi Seeds In DMN-induced Hepatic Fibrosis Rats

Objective: To investigate the effect of total flavonoids from Litchi chinensis Sonn(TFL)on liver fibrosis in rats by inhibiting the NLRP3 inflammatory vesicle pathway against dimethylnitrosamine(DMN),and to elucidate its anti-fibrotic mechanism of action,so as to provide a scientific basis for the treatment of liver fibrosis by TFL.Methods: Hepatic fibrosis in rats was triggered by continuous intraperitoneal injection of DMN and treated with TFL at high(180 mg/kg),medium(90mg/kg)and low(45 mg/kg)doses by gavage for 6 weeks.The rats were then tested for alanine aminotrrasferease(ALT),aspartate aminotransferase(AST),total protein(TP),albumin(ALB),hydroxyproline(Hyp),and hepatic fibrosis in serum.Hydroxyproline(Hyp),Hyaluronan(HA),Total bilirubin(T-BIL),Collagen type IV(Col-IV),Procollagen type III(PC III).Histomorphological changes in the liver of DMN rats after TFL intervention were observed by HE staining,and changes in the degree of liver fibrosis were observed by Masson staining.Changes in the expression levels of NLRP3,caspase-1,IL-1β and TXNIP m RNA in liver of DMN model rats with liver fibrosis after TFL intervention were detected by RT-q PCR.Changes in the expression levels of NLRP3,pro-caspase-1,caspase-1,pro-IL-1β,IL-1β,TXNIP,ASC proteins in liver of DMN model rats with liver fibrosis after TFL intervention were detected by Western blot.Results: After TFL high,medium and low dose treatment,the serum levels of ALT and AST viability and T-BIL concentration in liver fibrosis rats decreased significantly(P<0.01),and the ALB concentration increased significantly(P<0.01),and the TP content tended to increase.Detection of serum liver fibrosis markers revealed that Hyp levels in serum were significantly lower in the TFL high dose group compared to the model group(P<0.01),and Col IV,PC III,HA and LN levels were significantly lower in the TFL high,medium and low dose groups(P<0.01)(P<0.05 or P<0.01).HE staining and the results of HE staining and Masson staining showed that the degree of liver injury and fibrosis in the model rats were severe,while the degree of liver injury and fibrosis in the rats of each dosing group showed different degrees of reduction.The expression of NLRP3-related genes in rat liver tissues was detected by RT-q PCR,and the expression of Caspase-1,IL-1β,TXNIP and NLRP3 m RNA was significantly decreased in the high,medium and low dose groups of TFL(P<0.01).Meanwhile,Western blot detection revealed that TXNIP protein expression was significantly decreased in the TFL mid-dose group(P<0.01),ASC protein expression was significantly down-regulated in the TFL high,medium and low dose groups(P<0.01),and liver IL-1β,Pro-Caspase-1 protein was significantly decreased in the TFL high and low dose groups(P< 0.01 or P<0.05).Conclusion(s): TFL significantly improved DMN-induced liver fibrosis in rats,and inhibited the expression of TXNIP,NLRP3 and ASC,and reduced IL-1β.It is suggested that the mechanism of anti-liver fibrosis effect of TFL is to inhibit the expression of TXNIP protein,which may reduce the activation of NLRP3,thus inhibiting the activation of Caspase-1 and the release of inflammatory factor IL-1β,and reducing liver inflammation.The anti-fibrotic effect was achieved by inhibiting the expression of TXNIP protein.