Abstract: 【Objective】 This study was aimed to analyze and predict the potential active ingredients and targets of Cuscuta chinensis flavonoids in alleviating the reproductive damage of offspring exposed to bisphenol A (BPA) during pregnancy, to explore its possible mechanism of action, and then to protect animal reproductive function.【Method】 The potential targets of BPA were determined by searching the CTD database, and then the main active ingredients and potential targets in Cuscuta chinensis flavonoids were screened through the TCMSP database and TCMIP platform to obtain common targets of drugs and pollutants BPA, and the protein-protein interaction (PPI) network was constructed by using the STRING database, and the DAVID database was used for GO function and KEGG pathway enrichment analysis.AutoDock Tools 1.5.7 software was used to connect the main active ingredients with core targets.In the clinical experiment, 8-week-old SPF mice were used as the BPA exposure model during pregnancy, and the control group (gavage corn oil from 1 to 17 d of pregnancy, 0.2 mL/d), BPA group (gavage corn oil containing 5 mg/kg BW BPA from 1 to 17 d of pregnancy, 0.2 mL/d) and Cuscuta chinensis flavonoids group (gavage corn oil containing 5 mg/kg BW BPA and 40 mg/kg BW Cuscuta chinensis flavonoids by intragastric administration from 1 to 17 d of pregnancy, 0.2 mL/d) were set up.At the age of 21 days, the level of estrogen (E₂) in serum and the contents of ESR1 and ESR2 in ovarian tissue were measured.【Result】 The results suggested that the possible key ingredients of Cuscuta chinensis flavonoids were quercetin, kaempferol and isorhamna.There were 59 intersection targets of Cuscuta chinensis flavonoids and BPA.The five most highly correlated targets in the PPI network of Cuscuta flavonoids interfering with BPA were serine/threonine protein kinase 1 (AKT1), epidermal growth factor receptor (EGFR), estrogen receptor α (ESR1), mitogen-activated protein kinase 1 (MAPK1) and mitogen-activated protein kinase 1 (MAPK3).GO functional analysis showed that potential targets were enriched to a total of 375 items, mainly involving phosphorylation, cellular response to reactive oxygen species, membrane, cytoplasm, protein binding, nucleotide binding, transferase, and kinase activities, etc. KEGG pathway enrichment analysis showed that Cuscuta chinensis flavonoids were more abundant in cancer pathways, followed by estrogen signaling pathways, relaxin signaling pathways, endocrine resistance, and other pathways, which might be the most important signaling pathways of Cuscuta chinensis flavonoids to intervene in BPA.In addition, the intervention process was also related to the PI3K-Akt signaling pathway and GnRH signaling pathway.Molecular docking results showed that quercetin, kaempferol and isorhamnetin had high binding activity to the key targets of AKT1, EGFR, ESR1 and MAPK1, the ligand compounds could be stably placed in the active docking pocket of the receptor protein.Clinical trials had found that BPA extremely significantly reduced serum E₂ level in offspring mice (P<0.01), and extremely significantly increased ESR1 and ESR2 content (P<0.01), and disrupted endocrine homeostasis, while Cuscuta chinensis flavonoids could normalize hormone and receptor levels.【Conclusion】 The mechanism of action of Cuscuta chinensis flavonoids in alleviating reproductive injury caused by exposure to BPA during pregnancy was multi-target and multi-system, which could affect cancer pathways in addition to affecting endocrine related pathways.

Key words: Cuscuta chinensis flavonoids; bisphenol A (BPA); network pharmacology; molecular docking