Hepatoprotective Effect of Cynarin on Alpha-Naphthyl Isothiocyanate-Induced Cholestatic Liver Injury: Associated Modulation of TXNIP/NLRP3 and HMGB1/NF-κB Signaling Cascades.

Background: Cholestatic liver injury (CLI) is characterized by complex pathogenesis; however, oxidative stress-mediated inflammatory response due to bile acid accumulation in the liver is considered a primary cause. Cynarin (CN), an artichoke phytochemical, has demonstrated different biological activities, including antioxidant and anti-inflammatory ones. The current study aimed to explore the potential hepatoprotective effect of CN on CLI induced by alpha-naphthyl isothiocyanate (ANIT) in mice and investigate the possible involved mechanisms. Methods: Mice received CN (25 and 50 mg/kg) for four consecutive days and were challenged with ANIT (75 mg/kg) once on the second day. Liver injury was examined through biochemical determination of liver injury biomarkers and confirmed by histopathological evaluation. Oxidative stress biomarkers and pro-inflammatory cytokines were detected in the hepatic tissue. RT-PCR, Western blotting, and ELISA were applied to address gene and protein expression of potential underlying molecular targets, including thioredoxin-interacting protein (TXNIP), NLR family pyrin domain-containing 3 (NLRP3) inflammasome, and high-mobility group box 1 (HMGB1). Moreover, nuclear factor kappa-B (NF-κB) activation was determined by immunohistochemical analysis. Results: Our findings revealed that CN remarkably ameliorated ANIT-induced hepatic necro-inflammatory changes and biliary duct injury and restored redox balance in the liver. Mechanistically, CN markedly decreased the expression of TXNIP, NLRP3, active caspase-1, gasdermin D N-terminal (GSDMD-N), interleukin (IL)-1β, and IL-18, which were elevated upon ANIT administration. Moreover, CN suppressed ANIT-induced expression of HMGB1 and NF-κB. Conclusions: Our findings suggest that CN has a protective effect against ANIT-induced CLI in mice that is associated with modulation of the TXNIP/NLRP3 and HMGB1/NF-κB signaling cascades.