The mechanism of wen jing tang in the treatment of endometriosis: Insights from network pharmacology and experimental validation

Background: Endometriosis (EM) is a hormone-dependent condition marked by progressively severe secondary dysmenorrhea, significantly impacting patients' quality of life and overall health. Wen Jing Tang (WJT), a traditional Chinese medicinal formulation derived from the Synopsis of the Golden Chamber, has proven to be an effective therapeutic agent for EM. However, the precise molecular mechanisms underlying its efficacy remain unclear.

Objective: This study aims to elucidate the underlying mechanisms of WJT in the treatment of EM by integrating network pharmacology analysis with experimental validation.

Methods: The chemical constituents and target sites of WJT were obtained from the TCMSP database, while EM-related target genes were sourced from OMIM, TTD, GeneCards, and the DrugBank databases. A "herbs-components-targets" network was constructed using Cytoscape 3.9.1. The intersecting target genes of WJT and EM were then uploaded to the STRING database for protein-protein interaction (PPI) analysis. Subsequently, the common target genes were subjected to GO and KEGG enrichment analysis via the DAVID database. Molecular docking were employed to analyze the binding affinities between the top five core components and their respective targets. Additionally, ELISA were used to quantify the serum levels of IL-6, IL-1β, E2, and P in EM model rats. The expression levels of TNF-α, HIF1A, STAT3, and EGFR mRNA and proteins in ectopic endometrial tissue were assessed using q-PCR and Western blotting.

Results: A total of 250 chemical components and 553 targets were identified in WJT, while 3491 EM-related targets were screened from multiple databases. Among these, 187 common targets between WJT and EM were found, with quercetin, kaempferol, and beta-sitosterol emerging as the core chemical components, and AKT1, IL6, TNF, and IL1B identified as the key targets. These core components demonstrated strong binding affinities to the targets. GO and KEGG enrichment analyses revealed that the shared targets were primarily involved in the HIF1 signaling pathway. Furthermore, compared to the control group, the EM model rats exhibited an increased ectopic endometrial area, disordered glandular and stromal cells, and notable inflammatory infiltration. Serum levels of IL-6, IL-1β, E2, and P were significantly elevated (P < 0.01), and the expression of TNF-α, HIF1A, STAT3, and EGFR in the ectopic endometrium was markedly increased (P < 0.01). Following WJT intervention, the ectopic endometrial area in model rats was reduced, the morphology and structure of the endometrial cells showed improvement, and serum levels of IL-6, IL-1β, E2, and P were significantly decreased (P < 0.05). WJT also inhibited the expression of HIF1 pathway-related proteins TNF-α, HIF1A, STAT3, and EGFR (P < 0.05).

Conclusion: The mechanism by which WJT prevents and treats EM may involve the reduction of inflammation through the inhibition of the HIF1 signaling pathway.