Jiangtang Decoction for Type 2 Diabetes and NAFLD: Integrative Analysis via Network Pharmacology, Mendelian Randomization, Molecular Docking, and In Vitro Validation

Introduction: Jiangtang Decoction (JTD) demonstrates notable efficacy in managing Type 2 Diabetes Mellitus (T2DM) and Non-Alcoholic Fatty Liver Disease (NAFLD). This study aimed to elucidate JTD';s causal targets and therapeutic mechanisms by integrating network pharmacology, Summary-data Mendelian Randomization (SMR), and molecular docking, complemented by in vitro validation. Materials and Methods: JTD';s targets were cross-matched with genes associated with T2DM or NAFLD. SMR and co-localization analyses, utilizing eQTL and pQTL data, identified causal signals for each disease and their shared counterparts. GO/KEGG enrichment analyses were performed on these shared signals. Molecular docking assessed binding interactions. In vitro experiments, including ELISA (Enzyme-linked immunosorbent assay) and lipid staining, evaluated JTD';s hypoglycemic/hypolipidemic effects, while PCR/immunofluorescence validated key molecular predictions in High-Glucose and High-Lipid (HGHL)-induced HepG2 cells. Results: Initial network pharmacology identified 1107 JTD targets for T2DM and 1126 for NAFLD. SMR analyses revealed 78 eQTLs and 67 pQTLs for T2DM, and 40 eQTLs and 38 pQTLs for NAFLD. Eight shared causal genetic signals were identified: ADAMTS4, ALDH2, GLO1, CDH1, PDHB, PRKAB1, TCF4, and EP300. In vitro, JTD significantly attenuated hepatic gluconeogenesis and lipid deposition, downregulated IL-1β, and notably restored PRKAB1 expression in HepG2 cells treated with HGHL. Discussion: Enrichment analysis revealed shared processes, including membrane microdomains, oxidoreductase activity, and responses to nutrient and oxygen levels. PRKAB1 exhibited a strong binding affinity with the JTD component Salsalate. Conclusion: This study identified eight genes that are genetically predicted to be causal for the therapeutic effects of JTD on both T2DM and NAFLD, thereby establishing a genetic link between the conditions. These targets and associated pathways illuminate common underlying mechanisms, supporting JTD';s potential for integrated treatment strategies and providing a basis for further investigation.