An ErChen and YinChen Decoction Ameliorates High-Fat-Induced Nonalcoholic Steatohepatitis in Rats by Regulating JNK1 Signaling Pathway

ErChen and YinChen decoction (ECYCD) is an effective traditional Chinese medicine and has been widely used in traditional Chinese medicine to treat nonalcoholic steatohepatitis (NASH), with good curative effects. However, the specific mechanisms underlying these effects are unclear. In this study, we determined the efficacy of ECYCD in a high-fat diet-induced NASH rat model, established by 8-week administration of a high-fat diet. ECYCD was administered daily for 4 weeks, after which the rats were euthanized. The results demonstrated that ECYCD ameliorated high-fat diet-induced NASH, as evidenced by decreased liver indexes, reduced hepatic lipid deposition and liver injury, lower serum biochemistry markers (including low-density lipoprotein), and reduced HOMA-IR scores. Moreover, levels of free fatty acids, tumor necrosis factor, and malondialdehyde were decreased, whereas glutathione was increased in the liver. Serum high-density lipoprotein was also increased in the liver, and ECYCD regulated the c-Jun N-terminal kinase 1 (JNK1) signaling pathway by decreasing the levels of JNK1 protein, JNK1 mRNA, activator protein- (AP-) 1 protein, AP-1 mRNA, and phospho-insulin receptor substrate- (IRS-) 1ser307 and increasing phopsho-PKBser473 levels. These results suggested that ECYCD could ameliorate high-fat diet-induced NASH in rats through JNK1 signaling. ECYCD may be a safe therapeutic option for the treatment of NASH.