RESUMO
Objective To investigate the effect of ursolic acid(UA) on NOX2/ROS/NLRP3 inflammasome activation in carbon tetrachloride(CCl4)-induced liver fibrosis SD rat,and to observe the improvement of collagen deposition in liver tissues. Methods All rats were randomly divided into 3 group:control group,CCl4model group,UA treatment group. Liver fibrosis model SD rats was established by the CCl4-induced method and half of them was used as UA treatment group. Serum ALT was detected by ALT detection kit.The liver pathology and collagen deposition were ob-served by HE and Sirius-red staining. The mRNA expression of Nox2,Nlrp3,Caspase1,IL-1β in liver tissues was detected by RT-qPCR. The protein expression of NOX2,NLRP3,caspase-1 and IL-1β in liver tissues was detected by Western blot and immunohistochemistry and the ROS generation in liver tissues was detected by DCFH-DA fluores-cence probe. Results Compared with control group,in the CCl4model group,the serum ALT was much higher (P<0.05);the Ishak's fibrosis score and collagen deposition was significantly increased(P<0.05) and mRNA of Nox2, Nlrp3,Caspase1,IL-1β was increased.In addition,both the NOX2,NLRP3,caspase-1 p10 and IL-1β protein expres-sion and ROS level (P<0.05) of CCl4model group were significant increased.Compared with CCl4model group,in the UA treatment group Ishak's fibrosis score,collagen deposition and ALT decreased.Both mRNA expression of the Nox2, Nlrp3,Caspase1,IL-1β and protein expression of NOX2,NLRP3,caspase-1 p10 and IL-1β as well as ROS were signif-icant decreased,but the caspase-1 p45 protein level has no difference among all these groups (P>0.05). Conclusions Ursolic acid attenuates the liver injury and reduces the collagen deposition,which may relate to its inhibitory effects on NOX2/ROS/NLRP3 inflammasome activation to reduce IL-1β releasing.