| Background:Ischemia reperfusion injury(IRI)is a complication that is difficult to avoid in clinical events such as liver resection,liver transplantation,shock,and trauma.This pathological process causes irreversible damage to liver function and is often the primary cause of postoperative liver dysfunction,liver failure,and even death.There have been some basic research studies aimed at preventing or alleviating liver IRI,but there is still a lack of viable drugs or methods in clinical practice to protect the liver from the impact of IRI.There were growing evidences to suggest that hepatic ischemia and reperfusion promote the generation of reactive oxygen species and the secretion of pro-inflammatory cytokines,both of which contribute to hepatic injury.Therefore,anti-oxidative stress and anti-inflammatory responses may be effective therapeutic strategies for alleviating hepatic IRI.The purpose of this study is to investigate the effects of Spiraeoside(SPI)on hepatic IRI in rats and explore the molecular mechanisms underlying the action of SPI.Methods:42 SD rats were randomly divided into 7 groups with 6 rats per group.The groups were as follows: sham operation group,ischemia-reperfusion group,low,medium,and high dose SPI groups(50,100,and 150 mg/kg SPI injected intraperitoneally 1 hour before establishing the animal model,respectively),ML385group(30 mg/kg Nrf-2 specific inhibitor ML385 injected intraperitoneally 30 minutes before establishing the animal model),and SPI + ML385 group(100 mg/kg SPI + 30mg/kg ML385 injected intraperitoneally according to the same time points as above).The sham surgery group of rats underwent only laparotomy and portal dissection without vascular occlusion.The remaining six groups of rats had their hepatic artery,portal vein,and bile duct supplying the upper three lobes of the liver occluded for 1hour,followed by reperfusion for 6 hours after the removal of the vascular clamps.The serum levels of alanine aminotransferase(ALT)and aspartate aminotransferase(AST)were measured using an automated biochemical analyzer.Hepatic histopathological changes were observed using hematoxylin-eosin(H&E)staining.Malondialdehyde(MDA)and superoxide dismutase(SOD)levels in liver tissue were determined using corresponding assay kits.Additionally,serum levels of tumor necrosis factor-alpha(TNF-α)and interleukin-6(IL-6)were measured.Reactive oxygen species(ROS)and myeloperoxidase(MPO)levels in liver tissue were assessed using immunofluorescence(IF)technique.TUNEL staining was conducted to evaluate the level of in situ apoptosis in liver cells,and Western blot(WB)analysis was employed to measure the expression levels of apoptosis-related proteins.The mRNA and protein expression levels of the Nrf-2/HO-1 pathway were respectively assessed using quantitative real-time PCR(qRT-PCR)and WB techniques.Results:Compared to the sham surgery group,the ischemia-reperfusion group exhibited increased levels of serum AST and ALT,aggravated hepatic histopathological damage,elevated levels of MDA,ROS,and MPO in liver tissue,while SOD levels decreased.The serum levels of IL-6 and TNF-α were elevated.There was an increase in the number of TUNEL-positive cells,elevated expression of Bax and Caspase 3,and decreased expression of Bcl-2,Nrf-2,and HO-1 in liver tissue(P <0.05).Compared to the ischemia-reperfusion group,the low,medium,and high-dose SPI groups showed significant improvements in the aforementioned parameters(P<0.05).However,there were no significant differences observed among the medium and high-dose SPI groups for the aforementioned parameters(P >0.05).Compared to the SPI group,the SPI + ML385 group showed increased levels of serum AST and ALT,aggravated hepatic histopathological damage,elevated levels of MDA,while SOD levels decreased.The serum levels of IL-6 and TNF-α were elevated.There was an increase in the number of TUNEL-positive cells,elevated expression of Bax and Caspase 3,and decreased expression of Bcl-2,Nrf-2,and HO-1 in liver tissue(P <0.05).Conclusion:SPI can exert a protective effect on the liver of rats by alleviating oxidative stress,inflammatory response,and cell apoptosis-induced liver injury caused by IRI through activation of the Nrf-2/HO-1 signaling pathway. |
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