Regulation on mitophagy in adenomyosis by Guizhi Fuling Wan.

ETHNOPHARMACOLOGICAL RELEVANCE: Guizhi Fuling Wan (GZFLW), a canonical herbal formulation originating from Synopsis of the Golden Chamber, has been widely utilized in managing pain-associated disorders. While its therapeutic efficacy in adenomyosis (AM) characterized by severe dysmenorrhea is well-documented, the underlying pharmacological mechanisms remain elusive. Emerging evidence suggests that hypoxic mitochondrial damage in endometrial tissue constitutes a pathological hallmark of AM, wherein mitophagy regulation through the PINK1/Parkin signaling pathway plays a pivotal role in mitochondrial quality control. Although certain phytomedicines have demonstrated mitophagy-modulating properties under hypoxic conditions, the specific regulatory effects of GZFLW on this process in AM pathogenesis warrant systematic investigation.

AIM OF THE STUDY: To elucidate the mitophagy-modulating mechanism of GZFLW in AM through integrated in vivo and in vitro approaches.

MATERIALS AND

METHODS

An allogeneic pituitary transplantation-induced AM mouse model was established. Pharmacodynamic assessment included hotplate testing and serum cancer antigen 125 (CA125) quantification, while blood urea nitrogen (BUN) and alanine aminotransferase (ALT) levels were monitored for hepatorenal toxicity screening. Histopathological characterization employed hematoxylin-eosin (H&E) staining and transmission electron microscopy (TEM) for ultrastructural analysis. Protein expression of PINK1/Parkin pathway components (PINK1, Parkin, OPTIN, NDP52, P62) were determined by Western blot. Primary endometrial stromal cells (ESCs) isolated from clinical AM specimens underwent functional assessment via transwell migration/invasion assays, complemented by flow cytometric quantification of mitochondrial membrane potential (MMP) and reactive oxygen species (ROS). Molecular docking simulations evaluated ligand-receptor interactions between GZFLW bioactive constituents and PINK1/Parkin proteins. This study protocol was approved by the Medical Ethics Committee of China Three Gorges University (No. 2022CA002).

RESULTS

Histopathological validation confirmed successful AM model establishment. ELISA revealed significantly elevated CA125 levels in AM mice versus controls (P < 0.05), with notable reductions in GZFLW-treated groups (GET: P < 0.05, GZFLW-L: P < 0.01). No intergroup differences emerged in ALT/BUN levels, indicating absence of hepatorenal toxicity. Post-modeling pain threshold depression (P < 0.05 vs control) was attenuated by GZFLW treatment (P < 0.05). TEM analysis demonstrated mitochondrial pathology in AM endometrium, including structural deformation, reduced mitochondrial quantity, and autophagosome accumulation, all ameliorated by GZFLW-L intervention. Western blot showed upregulated PINK1 (P < 0.01), Parkin, OPTIN, and NDP52 (P < 0.05) in AM group, with subsequent downregulation following GZFLW-L administration (P < 0.05). In vitro, AM ESCs exhibited MMP depolarization (P < 0.05), reversed by GZFLW treatment alongside suppressed migratory/invasive capacity (P < 0.01, P < 0.05), ROS reduction (P < 0.05), and attenuated PINK1/Parkin pathway activation. Molecular docking confirmed strong binding affinities (binding energy < -5.0 kcal/mol) between GZFLW phytoconstituents and PINK1/Parkin targets.

CONCLUSION

This investigation reveals that GZFLW exerts its therapeutic effects on AM via targeted modulation of the PINK1/Parkin-mediated mitophagy axis, supporting its potential as a mitochondria-targeted therapeutic strategy for AM management.