Curculigoside Mitigates Hepatic Ischemia/reperfusion-induced Oxidative Stress,inflammation,and Apoptosis Via Activation Of The Nrf-2/HO-1 Pathway

Background and purpose:HIRI occurs after liver surgery and liver transplantation and is closely rela ted to the clinical prognosis of liver surgery.However,its pathogenesis is com plex and there is still a lack of effective methods for the prevention and treat ment of HIRI.Curculigoside(CUR),as a phenolic glycoside,is a bioactive co mpound extracted from the roots and stems of Curculigoside.Previous studies have confirmed that CUR has antioxidant stress and anti-inflammatory effects.However,whether it plays roles in liver ischemia-reperfusion injury is unclear.Therefore,the purpose of our study is to explore the role of CUR in rat HIRIand the possible molecular mechanisms.Methods:Forty male Sprague Dawley rats(200-250 g)were randomly divided into 5groups: sham group(sham group),ischemia-reperfusion group(IRI group),Curculigoside group(CUR group,20mg/kg),ML-385 group(an Nrf-2 inhibitor,30mg/kg),and CUR+ML-385 group.Both CUR and ML-385 were injected 30 minutes before laparotomy.After the establishment of a liver warm ischemia reperfusion model,the following indicators were collected from rat liver tissue and blood samples:(1)The levels of serum alanine transaminase(ALT)and aspartate transaminase(AST)in each group were measured using a biochemical analyzer to assess liver function damage;The collected liver tissue was subjected to HE staining and Suzuki score to assess liver histopathological damage.(2)the kit was used to detect the inflammatory factors’(IL-6,TNF-α)Expression level in the serum of each group.(3)Immunofluorescence staining was used to analyze the number of myeloperoxidase(MPO)positive cells in the liver tissues of every group.(4)The expression levels of malondialdehyde(MDA)and superoxide dismutase(SOD)in liver tissue of all group were measured using a kit.(5)TUNEL staining was used to test apoptosis in liver tissues of each group;Western blot(WB)was used for testing the expression of apoptosis-related proteins Bax,Bcl-2,caspase-3,and cleared caspase-3.(6)q PCR and WB were used for testing the m RNA and protein expression levels of Nrf-2 and HO-1.Results:1.Compared with the IRI group,CUR significantly reduced the levels of serum ALT and AST,alleviated congestion in liver tissue,as well as hepatocyte vacuolization and degeneration of liver cells,reduced the Suzuki score in liver tissue,and alleviated liver injury.CUR reduced serum inflammatory factor TNF-α And IL-6expression levels,reduced neutrophil infiltration in liver tissue,and alleviated liver aseptic inflammation.CUR also reduced the level of MDA in liver tissue and increase the content of SOD,and alleviated the oxidative stress caused by HIRI.In addition,CUR reduced the number of TUNEL positive cells in liver tissue,reduced the expression of proapoptotic proteins such as cleaved caspase-3 and Bax in liver tissue,promoted the expression of anti apoptotic protein Bcl-2,and alleviate HIRI induced apoptosis.2.Compared with IRI group,the m RNA and protein levels of Nrf-2 and HO-1were markedly increased in CUR group.Compared with IRI group,the m RNA and protein levels of Nrf-2 and HO-1 in ML-385 group were lower.Compared with the CUR group,the m RNA levels of Nrf-2 and HO-1 in the ML-385+CUR group decreased,and the changes of Nrf-2 and HO-1 at protein level were consistent with the m RNA changes.3.Compared with the IRI group,The level of serum transaminases(ALT,AST),inflammatory factors(TNF-α、 IL-6)and Suzuki score were significantly increased,and HE staining results showed that the degree of hepatocyte vacuolization and congestion in liver tissue was increased;The levels of MDA,MPO positive cells,and TUNEL positive cells in liver tissue increased significantly,while the levels of SOD decreased.Compared with the CUR group,the levels of serum transaminase,inflammatory factors,and Suzuki score in the ML-385+CUR group were higher than those in the CUR group,and the degree of liver tissue vacuolization and congestion was increased;The levels of MDA,MPO positive cells,and TUNEL positive cells in liver tissue increased,while the levels of SOD decreased.Conculsions:Curculigoside mitigates hepatic ischemia/reperfusion-induced oxidative stress,inflammation,and apoptosis via activation of the Nrf-2/HO-1 pathway...