Rabdosia japonica extract alleviate non-alcoholic steatohepatitis in mice by inhibiting the IRE1α-TRAF2-ASK1-JNK1 pathway

ZHANG Yifan; HU Xinyi; SHENG Liang

doi:10.13506/j.cnki.jpr.2026.01.001

Abstract：Objective To investigate the therapeutic effects and mechanisms of Rabdosia japonica extract(RJE)on non-alcoholic steatohepatitis(NASH).Methods NASH was induced in C57BL/6 mice using a choline-deficient,L-amino acid-defined high-fat diet(CDAHFD).The mice were treated with RJE(0.2 and 0.4 mL/10 g)for2 weeks.Serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)levels were measured.Liver pathology was assessed by hematoxylin-eosin(H&E),Oil Red O,and Sirius Red staining.Hepatic triglyceride(TAG)and hydroxyproline levels were quantitatively analyzed.RT-qPCR was used to measure mRNA expression of liver tumor necrosis factor-α(TNF-α),interleukin-1 β(IL-1β),monocyte chemoattractant protein-1(MCP-1),C-C motif chemokine ligand 5(CCL5),transforming growth factor-β(TGF-β),α-smooth muscle actin(α-SMA),and collagen type Ⅰ alpha 1(Collagen1a1).Western blotting was performed to analyze α-SMA protein expression.Potential therapeutic targets of RJE were predicted by intersecting RJE-related targets from network databases with NASH-related targets,followed by Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analyses.For in vitro experiments,AML-12 cells were treated with palmitic acid(PA,0.33 mmol·L-1)and lipopolysaccharide(LPS,1 μg·mL-1)to establish an NASH model.After RJE(5 μg·mL-1)intervention for 20 h,cell viability was assessed,and RT-qPCR was used to analyze inflammatory factor expression(TNF-α,IL-1β,MCP-1,CCL5).Western blotting was performed to detect key proteins in the IRE1α-ASK1-JNK1 pathway(P-IRE1α,P-ASK1,P-JNK1,P-c-Jun).Results RJE significantly ameliorated hepatic steatosis,inflammation,and fibrosis in NASH mice,reduced serum ALT and AST levels,and downregulated the expression of hepatic inflammatory and fibrotic markers(P＜0.05).In AML-12 cells,RJE improved cell viability,suppressed inflammatory cytokine mRNA expression,and inhibited the activation of the IRE1α-TRAF2-ASK1-JNK1 pathway(P＜0.05).Conclusion RJE alleviates NASH progression by inhibiting the hyperactivation of the IRE1α-TRAF2-ASK1-JNK1 pathway in AML-12 cells,reducing endoplasmic reticulum stress,attenuating hepatocyte apoptosis,and mitigating inflammatory responses.