Formononetin alleviates ovarian fibrosis and inflammation via targeting SOCS3 and inhibiting TGF-β1/Smad signaling in PCOS

Objective

Polycystic ovary syndrome (PCOS) is an endocrine and metabolic disorder characterized by ovulatory dysfunction. Formononetin (FMN), a bioactive compound derived from leguminous plants, including Glycyrrhiza uralensis, Trifolium pratense, and Astragalus membranaceus, exhibits anti-inflammatory and anti-fibrotic properties. This study aimed to evaluate the therapeutic effects of FMN in a PCOS rat model and elucidate its underlying molecular mechanisms.

Methods

A PCOS-like model was established in 3-week-old female Sprague-Dawley rats by daily dehydroepiandrosterone (DHEA) injections. The efficacy of FMN was assessed by monitoring estrous cycles, hormone levels, glucose tolerance, and ovarian tissue morphology. Network pharmacology and transcriptome sequencing were used to predict the molecular targets and signaling pathways of FMN. The binding and stabilizing effects of FMN on suppressor of cytokine signaling 3 (SOCS3) were confirmed using molecular docking, molecular dynamics (MD) simulations, and cellular thermal shift assay (CETSA)-Western blotting (WB) (CETSA-WB). The expression of SOCS3, inflammation- and fibrosis-related markers, and the components of the transforming growth factor beta1 (TGF-β1)/Smad pathway were quantified by quantitative polymerase chain reaction (qPCR), WB, and immunohistochemistry. Functional validation was performed using SOCS3 small interfering RNA (siRNA).

Results

DHEA successfully induced a PCOS-like phenotype, including disrupted estrous cycle, hyperandrogenism, an elevated luteinizing hormone to follicular stimulating hormone (LH/FSH) ratio, insulin resistance, and abnormal ovarian morphology. FMN treatment significantly reversed these abnormalities and reduced ovarian collagen deposition. Network pharmacology and transcriptome analyses indicated that the therapeutic efficacy of FMN was primarily attributable to its anti-fibrotic and anti-inflammatory properties, with SOCS3 identified as a potential key molecule. Molecular docking and MD simulations, along with CETSA-WB, further revealed that FMN directly binds to SOCS3, enhancing its stability and thereby inhibiting ovarian fibrosis in PCOS. Moreover, qPCR, WB, and immunohistochemistry confirmed that FMN regulates the TGF-β1/Smad signaling pathway. Importantly, SOCS3siRNA abolished fibrotic-related collagen levels and phosphorylated signal transducer and activator of transcription 3 (p-STAT3) expression, supporting the notion that FMN ameliorates PCOS-induced ovarian fibrosis via SOCS3.

Conclusion

FMN alleviated ovarian dysfunction and hyperandrogenism in DHEA-induced PCOS rats by stabilizing SOCS3 and inhibiting TGF-β1/Smad signaling, thereby attenuating ovarian fibrosis and inflammation. This reveals a novel SOCS3-centered mechanism for FMN and underscores its therapeutic potential for PCOS.