Cyclophosphamide-induced animal models of ovarian dysfunction: from molecular mechanisms and modeling strategies to validation criteria.

The prevalence of ovarian dysfunction is rising annually and trending toward younger populations, significantly compromising the quality of life and reproductive potential of women in their prime childbearing years. Given the multifactorial etiology and complex pathogenesis, ovarian dysfunction requires robust animal models to elucidate underlying mechanisms and evaluate therapeutic efficacy. Due to its well-documented gonadotoxicity, cyclophosphamide (CTX) has become a cornerstone in establishing standardized models of ovarian dysfunction. This review provides a systematic summary of the core mechanisms underlying CTX-induced ovarian dysfunction, with an emphasis on their interconnected regulatory network encompassing oxidative stress, DNA damage and defective repair, apoptosis, cellular senescence, immune-inflammatory responses, autophagy, and ferroptosis. Furthermore, it delineates modeling protocols, encompassing animal species selection, dosing regimens, validation criteria, and outcome evaluation. Several critical limitations in current modeling practices have been identified, including significant inter-study variability in dosing regimens, the indiscriminate application of uniform doses across distinct disease stages, and a dearth of standardized benchmarks for both model establishment and outcome evaluation. Future studies should clarify the mechanistic crosstalk in CTX-induced ovarian injury and identify potential therapeutic targets. Moreover, it is essential to delineate the dose-response relationships, establishment criteria, and evaluation metrics specifically tailored to DOR, POI, and POF. Establishing standardized, graded modeling protocols is critical to providing a reliable framework for the clinical translation of basic research findings.