Melatonin Rescues Triclosan-Disrupted Porcine Oocyte Meiosis via Suppression of p53-Mediated Apoptosis

Triclosan (TCS), a widely used environmental antimicrobial agent, poses potential risks to female reproductive health, yet its toxic effects on oocyte maturation remain inadequately characterized. In this study, we established an in vitro maturation (IVM) model of porcine oocytes to investigate TCS-induced meiotic impairment and to evaluate the rescuing effects of melatonin (MT), an endogenous indoleamine with potent antioxidant and anti-apoptotic activities. Our results demonstrated that TCS exposure significantly disrupted oocyte maturation, as evidenced by suppressed polar body extrusion and compromised cumulus expansion. Furthermore, TCS triggered early apoptosis. Proteomic analysis revealed that the p53 signaling pathway was significantly dysregulated by TCS exposure. Notably, co-treatment with MT during IVM effectively restored meiotic progression, attenuated apoptosis, and rebalanced the disrupted proteomic profile. Mechanistic investigation, validated by Western blotting, confirmed that TCS upregulated p53 and downregulated its downstream cell cycle effector CCNB1 while concurrently altering the ratio of apoptosis-related proteins BAX/BCL-2. Melatonin treatment effectively normalized the expression of these key proteins (p53, CCNB1, BAX, and BCL-2). These findings illustrate that MT rescues TCS-impaired oocyte quality through p53-dependent suppression of apoptosis and restoration of meiotic progression, providing new insights into potential strategies for mitigating environmental pollutant-induced reproductive damage.