[Study on mechanism of Wendan Decoction in intervening in nonalcoholic fatty liver disease based on proteomics and...

This study systematically explored the molecular mechanism of Wendan Decoction(WDD) in treating nonalcoholic fatty liver disease(NAFLD) by integrating network pharmacology, proteomics, and experimental validation. A mouse NAFLD model was established using a high-fat diet, and the mice were randomly divided into a blank control group, a model group, a positive drug group(simvastatin, 3.03 mg·kg~(-1)), and low-(3.035 g·kg~(-1)), medium-(6.07 g·kg~(-1)), and high-dose(12.14 g·kg~(-1)) WDD groups, with intervention lasting for 6 weeks. After the intervention, the serum levels of alanine aminotransferase(ALT), aspartate aminotransferase(AST), triglycerides(TG), total cholesterol(TC), low-density lipoprotein cholesterol(LDL-C), and high-density lipoprotein cholesterol(HDL-C) were measured using an automatic biochemical analyzer. The serum levels of interleukin-1β(IL-1β), interleukin-6(IL-6), and tumor necrosis factor-α(TNF-α) were detected by ELISA. Liver histopathology was observed via hematoxylin-eosin(HE) staining and oil red O staining. Network pharmacology was used to predict potential targets and pathways, and proteomics was applied to identify differentially expressed proteins and related pathways. RT-qPCR and Western blot were performed to detect mRNA and protein expression of relevant genes. Animal experiments demonstrated that WDD dose-dependently ameliorated hepatic steatosis, inflammation, and lipid deposition, significantly reducing serum levels of ALT, AST, TG, TC, LDL-C, and pro-inflammatory cytokines(IL-1β, IL-6, and TNF-α), while significantly increasing serum HDL-C levels. Network pharmacology screening identified naringenin, baicalein, and other key active components, which were involved in pathways such as the peroxisome proliferator-activated receptor(PPAR), lipid, and atherosclerosis pathways. Proteomics further revealed differentially expressed pathways including the PPAR and advanced glycation end product-receptor(AGE-RAGE) signaling pathways. Integrated analysis highlighted the PPAR signaling pathway as the core mechanism. Molecular biology validation showed that WDD significantly regulated the mRNA expression of sterol regulatory element-binding protein-1c(SREBP-1c), fatty acid synthase(FASN), carnitine palmitoyl transferase 1A(CPT1A), acyl-CoA oxidase 1(ACOX1), and PPARα, as well as protein expression of PPARα, CPT1A, and PPARγ in mouse liver tissue. These results suggested that WDD might exert a multi-component, multi-target, and multi-pathway synergistic effect to improve lipid metabolism disorders and inflammatory responses with the PPAR signaling pathway as the central hub, thereby alleviating NAFLD progression.