Role and mechanisms of plant polyphenols in ovarian aging

The ovary is a vital organ in female animals, playing a crucial role in regulating reproductive and endocrine functions. Ovarian aging is characterized by declining oocyte quality and ovarian reserve quantity, ultimately leading to infertility and increased risk of age-related diseases. Oxidative stress, inflammation, endocrine disorders, and ovarian microenvironmental disruption are central mechanisms contributing to ovarian aging. Despite the growing incidence of delayed childbearing, there are limited effective interventions to preserve ovarian function. Plant polyphenols, a diverse group of naturally occurring compounds with potent biological activities, have emerged as promising candidates for improving ovarian function and reproductive health. However, a comprehensive synthesis of their classification, mechanisms of action, translational potential, and clinical application prospects remain lacking. In this review, we describe the mechanisms of ovarian aging, systematically classify plant polyphenols and summarize their specific bioactivities related to ovarian function. Furthermore, we highlight that these natural compounds have the potential to delay ovarian aging by alleviating oxidative stress, reducing inflammation, modulating hormone balance, and regulating gut microbiota. Consequently, they hold promise as a novel intervention strategy to mitigate the adverse outcomes of ovarian aging. While plant polyphenols hold considerable promise, several critical challenges remain unresolved, specifically inconsistent dosing regimens, poor bioavailability, and a lack of robust clinical validation. Overall, this review aims to provide a comprehensive overview of the protective roles and underlaying biological mechanisms of plant polyphenols in ovarian aging and propose future research directions for developing safe and effective plant polyphenol-based interventions for female reproductive longevity.