Objective To explore the effect of lidocaine(LID)on ischemia-reperfusion injury in orthotopic liver transplantation(OLT)rats and to analyze its mechanism of action.Methods Sixty rats were randomly divided into Verteporfin group,high-dose LID(High LID),medium-dose LID(Medium LID),low-dose LID(Low LID),Model and Control groups,on average.The rest of the rats except the control rats were used to establish OLT models.Observe the pathological changes in liver tissue were with hematoxylin-eosin staining.Serum aspartate transaminase(AST),total bilirubin(TBIL),lactate dehydrogenase(LDH)activities and alanine transaminase(ALT)were detected.Measure liver tissue levels of proinflammatory factors tumor necrosis factor-α(TNF-α),interleukin(IL)-6,IL-1β,and IL-10 with enzyme-linked immunosorbent assays.Reactive oxygen species(ROS)was detected by a fluorescence probe.Malondialdehyde(MDA)was detected by the thiobarbituric acid colorimetric method.Superoxide dismutase(SOD)was detected by nitrogen blue tetrazole colorimetry.Glutathione peroxidase(GSH-Px)was detected by a spectrophotometry method.Apoptosis of liver histiocytes was detected by in situ end labeling.Detect the expression of mammalian STE20 like protein kinase(MST1),phosphorylation(p)-MST1,large tumor suppressor factor 1(LATS1),p-LATS1,Yes associated protein(YAP),p-YAP,and apoptosis-related proteins B-cell lymphoma 2(Bcl-2)and Bcl-2 related X protein(Bax)with Western blot.Results Compared with the Control group,liver tissue in Model group rats showed injury,liver cell necrosis,and a large degree of inflammatory cell infiltration.Moreover,the cell apoptosis rate;serum AST,ALT,TBIL,and LDH activities;and liver tissue levels of TNF-α,IL-6,IL-1β,MDA,ROS,and Bax were significantly increased.Furthermore,liver tissue levels of IL-10,SOD,GSH-Px,Bcl-2,p-MST1/MST1,p-LATS1/LATS1,and p-YAP/YAP proteins were significantly reduced(P＜0.05).Compared with the Model group,liver tissue injury was reduced in Low LID,Medium LID,and High LID groups.The cell apoptosis rate;serum AST,ALT,TBIL,and LDH activities;and liver tissue levels of TNF-α,IL-6,1L-1β,MDA,ROS,and Bax were significantly reduced.Moreover,liver tissue levels of IL-10,SOD,GSH-Px,Bcl-2,p-MST1/MST1,p-LATS1/LATS1,and p-YAP/YAP proteins were significantly increased(P＜0.05).Hippo-YAP signaling pathway inhibitor verteporfin reversed the improving effect of LID on ischemia-reperfusion injury in OLT rats(P＜0.05).Conclusions LID may activate the Hippo-YAP pathway,which reduces the inflammatory response,oxidative stress,and liver cell apoptosis,and improves liver ischemia-reperfusion injury in OLT rats.