Study On The Mechanism Of Probiotics VSL#3 Inhibition Carbon Tetrachloride-induced Liver Fibrosis In Mice

Objective: To study the effect of intestinal probiotic VSL#3 on carbon tetrachloride-induced liver fibrosis in mice.Methods: Selecte for 6-8weeks of healthy C57BL/6 male mice to established liver fibrosis model induce by CCl4.HE staining,Sirius red staining,and Analysis of activation of STAT3 pathway in the model of liver fibrosis in mice by Western blot.The experimental design was grouped into olive oil control group,Stattic group,CCl4 group,Stattic+ CCl4 group(Stattic is Stat3 inhibitor).6 mice in each group,CCl4 intraperitoneal injection 3 times a week,at a dose of 4 m L/kg,the control group was injected with olive oil.The same time given intraperitoneal injection of Stattic mice,3mg/kg/day,continuous administration of 4 weeks after the mice were sacrificed to collect liver specimens.The effect of Stattic on liver injury induced by CCl4 in mice was analyzed by Sirius red staining.The experimental design was divided into olive oil control group,VSL#3group,CCl4 group,VSL#3+CCl4 group,and 6 mice in each group.CCl4 was injected intraperitoneally 3 times a week,with a dose of 4 m L/kg.The control group was injected with equal amount of olive oil.Meanwhile,probiotics VSL#3 was given 1 times a day,and 0.6g/Kg/d was administered continuously for 4 weeks.Serum and liver samples were collected from mice.Using HE staining and serum transaminase(AST,ALT)detection and analysisof effect of VSL#3 on mice liver injury induced by CCl4;using Sirius red staining and Western blot analysis of the effect of probiotics VSL#3 on CCl4 induced liver fibrosis in mice;Using western blot to detect the activation of stat3 in liver fibrosis in mice induced by intestinal probiotics VSL#3.Results:(1)CCl4 could effectively induce liver fibrosis in mice: The results of HE staining showed that there were more vacuoles and nodular necrosis in the liver tissues of the mice treated with CCl4.This suggests that CCl4 induced the injury of liver tissue in mice.In addition,The results of Sirius red staining showed the accumulation of collagen fibrils in the liver tissues of CCl4 treated mice.At the same time,The results of Western blot showed that the alpha-SMA in the liver tissues of mice treated with CCl4 was obviously up-regulated.This suggests that CCl4 induced liver fibrosis in mice,which confirmed that CCl4 can effectively induce liver fibrosis in mice(2)Stat3 was activated in mouse liver fibrosis model: Western blot results showed that the activation of STAT3 in mouse fibrosis model induced by CCl4 phosphorylation in liver tissue was significantly higher than the control group.This suggests that the activation of stat3 in mouse liver tissue induced by CCl4 demonstrates that the stat3 signaling pathway is activated in mouse liver fibrosis.(3)Inhibition of Stat3 can alleviate liver fibrosis in mice:The results showed that the accumulation of collagen fibers in the Stattic+ CCl4 group was significantly lower than that in the individual CCl4 group.This suggests that Stattic inhibits liver fibrosis.In addition,Western blot results showed that Stattic+CCl4 group was significantlydown regulated than that of CCl4 group,indicating that STAT3 inhibited CCl4 induced liver fibrosis in mice.(4)VSL#3 can alleviate liver damage induced by CCl4: the results of HE staining indicate that VSL#3 can effectively reduce vacuolated and nodular necrosis of liver tissue.This suggests that VSL#3alleviates CCl4 induced liver damage in mice.In addition,serological liver function indicators showed that AST and ALT in group VSL#3+CCl4 were significantly lower than those in group CCl4,which was consistent with the above results.It is confirmed that VSL#3 can alleviate CCl4 induced liver injury in mice.(5)VSL#3 inhibited CCl4 induced liver fibrosis in mice:Sirius red staining indicated that the collagen fiber accumulation in VSL#3+CCl4 group was significantly lower than that in CCl4 group alone.This suggests that VSL#3 alleviates CCl4 induced liver fibrosis in mice.In addition,the results of Western blot showed that the hepatic stellate cell marker-alpha-SMA of the VSL#3+CCl4 group was significantly reduced,which was consistent with the above results.It is confirmed that VSL#3 inhibits CCl4 induced accumulation of hepatic fibers in mice.(6)probiotics inhibit CCl4 induced activation of Stat3 in liver of mice: Western blot results showed that Stat3 phosphorylation in VSL#3+CCl4 group was significantly lower than that in single CCl4 group.This suggests that probiotics inhibit the activation of the STAT3 pathway induced by CCl4.