To investigate the effect of ethanol extract of Guijianyu（Euonymus Alatus）on CCl₄-induced liver fibrosis model mice based on Rho A/ROCK signaling pathway.

Fifty C57BL/6 mice were randomly divided into normal group（NG），model group（MG），low-dose group of Guijianyu（Euonymus Alatus）（EA-L），medium-dose group of Guijianyu（Euonymus Alatus）（EA-M），high-dose group of Guijianyu（Euonymus Alatus）（EA-H），10 mice in each group.The mice in all groups except NGwere modeled by intraperitoneal injection of olive oil suspension containing25%CCl₄.At the same time of modeling，NG and MG were treated with double-distilled water by gavage，and the remaining three groups were treated with Guijianyu（Euonymus Alatus）by gavage with the corresponding doses（2 g/kg，4 g/kg and 8 g/kg，equivalent to the amount of the raw drug contained），respectively.6 weeks later，the serum and liver tissues were collected，and the liver function indexes［glutamic oxalacetic transaminase（AST），glutamate pyruvate transaminase（ALT）］were detected.ELISA method detected the levels of tumor necrosis factor-α（TNF-α），interleukin-6（L-6），hydroxyproline（HYP）and transforming growth factor-β1（TGFβ1）.HE and Masson staining were used to analyze the damage and collagen deposition in the liver of mice.The expressions of α-SMA，Collagen I and the relative protein expressions of Rho A/ROCK signaling pathway related proteins in the liver tissues were detected by Western blot.

Compared with those of MG，the serum levels of ALT，AST，TNF-αand IL-6 of EA-M and EA-H showed a decreasing trend. Compared with those of MG，the contents of Hyp and TGF-β1 in liver tissues of the Guijianyu（Euonymus Alatus）groups decreased to different degrees（P<0.05，P<0.01）.The hepatic morphology and structure，cellular inflammatory infiltration，fibrous changes and collagen deposition in the Guijianyu（Euonymus Alatus）groups were dose-dependently better than that of MG.The protein expression levels ofα-SMA，CollagenⅠand Rho A/ROCK signaling pathway related proteins in the EA-L，EA-M and EA-H were decreased compared with those of MG（P<0.05，P<0.01）. Compared with those of MG，the mRNA expressions ofα-SMA，CollagenⅠand Rho A/ROCK signaling pathway related proteins were decreased in EA-L，EA-M and EA-H（P<0.05，P<0.01）.

Ethanol extract of Guijianyu（Euonymus Alatus）has obvious enzyme-lowering，hepatoprotective and antihepatic fibrosis effects，and inhibition of the Rho A/ROCK signaling pathway is one of the mechanisms of its anti-hepatic fibrosis action.