OBJECTIVE: To dynamically observe the efficacy of Jieduan Niwan formula(JDNW) on a rat model of acute-on-chronic liver failure(ACLF).METHODS: Seventy Wistar rats were divided into control group(6 rats), model group(22 rats), JDNW group(21 rats), and SP600125 group(21 rats).13 weeks' porcine serum injection followed with D-galactosamine and lipopolysaccharide joint acute attack was used to establish ACLF model.Rats in JDNW group were orally given JDNW formula for 3 days before acute attack; rats in SP600125 group were injected with SP600125 30 min ahead of acute attack. Rats were sacrificed respectively at4, 8 and 12 h after model established. Alanine aminotransferase(ALT), aspartate aminotransferase(AST), total bilirubin(TBIL), Creatinine(CR), blood urea nitrogen(BUN), prothrombin activity(PTA)were examined by biochemical process, Tumor necrosis factor-alpha(TNF-α), interleukin-1β(IL-1β),interleukin-6(IL-6), interleukin-10(IL-10), transformed growth factor-beta 1(TGF-β1), High mobility group box-1(HMGB-1), CD3, CD4, CD8 were analyzed by enzyme-linked immunosorbent assay, apoptotic index(AI) was detected by terminal-deoxynucleoitidyl transferase mediated nick end labeling staining, expression of Bad, phosphorylated Jun N-terminal kinases(p-JNK) and Cytochrome C(Cyt C) were detected by immunohistochemical analysis, Bax and Bid were detected by Western blot analysis.RESULTS: In model group, the levels of ALT, AST,TBIL, CR, BUN, IL-1β, IL-6, IL-10, TGF-β1 and HMGB-1 remarkably increased and PTA decreased compared with control group(P < 0.05), as time goes on, ALT, AST, TBIL, CR, BUN, continued to grow,while IL-1β, IL-6, IL-10, HMGB-1, TGF-β1 and PTA gradually decreased; massive necrosis could be seen; the levels of TNF-α, CD3, CD4, CD8, AI, p-JNK,Bax, Bad, Bid and Cyt C increased at 4 h and peaked at 8 h, but decreased at 12 h(P < 0.05). JDNW group, by contrast, showed less pathological injury,increased PTA level, and reduced ALT, AST, TBIL,TNF-α, IL-1β, IL-6, IL-10, TGF-β1, HMGB-1, CD3, CD4 and CD8 levels(P < 0.05), moreover, the AI and expression of p-JNK, Bax, Bad, Bid and Cyt C were lower than model group at 4 and 8 h but were higher at 12 h(P < 0.05). Similar results were observed in SP600125 group.CONCLUSION: An ACLF rat model with low mortality can be established by porcine serum joint with D-galactosamine + lipopolysaccharide induction;JDNW decoction can effectively suppress the inflammatory reaction, improve the immune system,and protect the liver of ACLF rats, the mechanism might involve the inhibition of the JNK-induced mitochondrial apoptotic pathway.