Protective Role of N-Acetyl-L-Tryptophan against Hepatic Ischemia-Reperfusion Injury by the TLR4/NF-KB Signaling pathway

Background: Hepatic Ischemia-reperfusion injury (HIRI) is a complex process during liver resection and transplantation. The purpose of this study was to investigate whether N-acetyl-L-tryptophan (L-NAT) could protect hepatocytes against acute hepatic ischemia-reperfusion injury through the Toll-Like Receptor 4(TLR4)/nuclear transcription factor-kappa B (NF-kappa B) signaling pathway and its possible mechanisms. Methods: The expression of SP and NK-1R were detected in rat models of hepatic ischemia-reperfusion injury. The activity of NF-kappa B and TLR4 were detected in H2O2-induced by the BRL oxidative damage model. Results: (1) Immunohistochemical staining showed that the expression of substanceP (SP) and Neuroknin 1 Receptor (NK-1R) increased after hepatic ischemia-reperfusion injury (HIRI). (2) L-NAT pretreatment could inhibit the expression of nuclear transcription factor Kappa-B (NF-kappa B) and toll-like receptor 4 (TLR4) induced by HIRI. Conclusion: Taken together, the increased of SP and NK-1R after HIRI revealing that neurogenic inflammatory responsewas involved inHIRI. The results that L-NATsignificantly decreased the increasing of NF-kappa B and TLR4induced byHIRI implies that L-NAT protects liver against hepatic ischemia-reperfusion injury through TLR4/NF-kappa B signaling pathway.