The main active monomer of Dan'e-fukang soft extract, liquiritin, inhibits the inflammation and invasion of ectopic endometrial stromal cells through down-regulation of CCL2

The study explored the mechanism of Dan'e-fukang soft extract in treating endometriosis (EMs) through network pharmacology. The main active ingredients of Dan'e-fukang soft extract were analyzed based on the traditional Chinese medicine systems pharmacology database and analysis platform (TCMSP). Drug target genes were mined by PubChem, and differential genes were analyzed based on Gene Expression Omnibus (GEO) database microarrays GSE7305, GSE11691, and GSE12768. A total of 101 differential drug target genes were screened. Gene Ontology (GO) analysis revealed that the 101 differential drug target genes were mainly enriched in the regulation of cell migration, inflammatory response, and cytokine-mediated signaling pathways; among them, factors associated with both inflammatory response and negative regulation of cell migration were allograft inflammatory factor 1 (AIF-1), C-C motif chemokine ligand 2 (CCL2), and Cadherin-1 (CDH1), of which CCL2 was upregulated in all three endometriosis-related GEO datasets. CCL2 was also upregulated in endometriosis patient tissues as well as in ectopic endometrial stromal cells (ESCs). The overexpression of CCL2 in normal ESCs promoted cell proliferation, migration, invasion, and expression levels of inflammatory factors (TNF-α, IL-1β, and IL-6). However, the silencing of CCL2 in ectopic ESCs had the opposite result. Liquiritin was identified as a potential key active monomer of Dan'e-fukang soft extract based on network pharmacology prediction. Liquiritin inhibited CCL2 expression and inhibited proliferation, migration, invasion, and inflammation in ectopic ESCs, while overexpression of CCL2 partially reversed these functions of liquiritin. Liquiritin inhibits ectopic ESC proliferation, migration, and inflammation by inhibiting CCL2 and thereby alleviating endometriosis.