Nuangong Tiaojing Formula ameliorates luteal phase defect by restoring ovarian-uterine axis function via regulating inflammatory-apoptotic cascade.

BACKGROUND

Luteal phase defect (LPD) is a prevalent endocrine disorder contributing significantly to female infertility and early pregnancy loss. Nuangong Tiaojing Formula (NTF), a traditional Chinese medicine formula, has demonstrated clinical efficacy in treating LPD, yet its underlying mechanisms remain incompletely elucidated.

PURPOSE: This study aimed to explore the curative effects and mechanisms of NTF in LPD-related ovarian endocrine dysfunction and endometrial receptivity defects.

METHODS

UPLC-Q-TOF-MS/MS and HPLC technologies were utilized to identify and quantify the chemical components in NTF, respectively. An LPD rat model was established using mifepristone. The therapeutic effects of NTF on estrous cyclicity, serum progesterone (P) and estradiol (E2) levels, and ovarian and uterine histopathology were evaluated. Network pharmacology analysis predicted the underlying biological mechanism modulated by NTF, which were subsequently validated using molecular biology methods, such as Western blotting, ELISA, and TUNEL staining. Component-effect correlation analysis, in silico simulations, and pharmacokinetic study were conducted to identify candidate efficacious ingredients of NTF and their in vivo kinetic characteristics.

RESULTS

NTF treatment significantly ameliorated LPD-related pathologies in a dose-dependent manner, including restored estrous cyclicity, increased serum P and E2 levels, and improved ovarian morphology and endometrial receptivity. NTF also reduced the secretion of pro-inflammatory cytokines TNF-α and IL-1β, and modulated lipid peroxidation markers such as SOD and MDA. Mechanistically, the therapeutic effects of NTF on restoring ovarian endocrine function and its downstream endometrial receptivity in LPD was closely associated with the suppression of ovarian inflammatory-apoptotic cascade mediated by the TLR4/MyD88/NF-κB/Bcl-2/Bax/Caspase-3 pathway. Component-effect correlation analysis, in silico simulations, and pharmacokinetic data suggested that Paeoniflorin, Albiflorin, Morroniside, Loganin, Salvianolic acid B, Gallic acid, and Hyperoside were candidate efficacious components of NTF, exhibiting stable binding interactions with core targets of the aforementioned pathway and multi-level exposure characteristics, supporting their potential for synergistic therapeutic effects.

CONCLUSION

This study innovatively demonstrates that NTF effectively restores ovarian-uterine axis function in LPD probably by multi-target regulation of the inflammatory-apoptotic cascade, primarily via the TLR4/MyD88/NF-κB/Bcl-2/Bax/Caspase-3 pathway. Our findings present novel mechanistic insights into the curative effect of NTF against LPD.