Revealing the mechanism of heptamethoxyflavone against diabetic kidney disease: an integrated study combining network pharmacology, molecular docking and experimental validation.

3,5,6,7,8,3',4'-Heptamethoxyflavone (HMF), a natural component derived from Citrus plants, shows potential for the treatment of metabolic diseases. However, its therapeutic role in diabetic kidney disease (DKD) remains unclear. In this study, we intragastrically administered HMF (50 mg kg-1 d-1) to db/db mice for 12 weeks, followed by pharmacodynamic analysis. We then used network pharmacology to predict therapeutic targets by retrieving HMF drug targets from Swiss TargetPrediction, PharmMapper, and TCMSP, and DKD-related targets from GeneCards, OMIM, and DisGeNET. Overlapping targets were subjected to STRING-based PPI network construction, Cytoscape visualization, and CytoNCA-based core target screening. GO and KEGG enrichment analyses were performed via DAVID, and molecular docking was conducted using AutoDock Vina to validate the binding affinity between HMF and key targets. Finally, RT-qPCR and Western blotting were employed in HG-induced HK-2 cells and db/db mice to verify the effects of HMF on target proteins and related pathways. In vivo studies validated the therapeutic efficacy of HMF in DKD, demonstrating reduced hyperlipidemia, improved renal function, and attenuated renal pathology. Network pharmacology predicted 17 key genes underlying the mechanism of action of HMF. Enrichment analyses suggested the PI3K-AKT signaling pathway was involved in its therapeutic effects, while molecular docking predicted high-affinity binding of HMF to EGFR, CASP3, ESR1, MMP9, HSP90AB1, and AKT1. Furthermore, experimental findings demonstrate that HMF upregulates the key target ESR1 and downregulates PI3K, AKT1, and MMP9, whereas no significant changes are observed in CASP3 and HSP90AB1. These results demonstrate that HMF protects against DKD by regulating the ESR1/PI3K/AKT pathway, supporting its therapeutic potential.