Melatonin protects against oxybenzone-induced deterioration of mouse oocytes during maturation.

Oxybenzone (OBZ), an ultraviolet light filter that is widely used in sunscreens and cosmetics, is an emerging contaminant found in humans and the environment. Recent studies have shown that OBZ has been detected in women’s plasma, urine, and breast milk. However, the effects of OBZ exposure on oocyte meiosis have not been addressed. In this study, we investigated the detrimental effects of OBZ on oocyte maturation and the protective roles of melatonin (MT) in OBZ-exposed mouse models. Our in vitro and in vivo results showed that OBZ suppressed oocyte maturation, while MT attenuated the meiotic defects induced by OBZ. In addition, OBZ facilitated H3K4 demethylation by increasing the expression of the Kdm5 family of genes, elevating ROS levels, decreasing GSH, impairing mitochondrial quality, and disrupting spindle configuration in oocytes. However, MT treatment resulted in significant protection against OBZ-induced damage during oocyte maturation and improved oocyte quality. The mechanisms underlying the beneficial roles of MT involved reduction of oxidative stress, inhibition of apoptosis, restoration of abnormal spindle assembly and up-regulation of H3K4me3. Collectively, our results suggest that MT protects against defects induced by OBZ during mouse oocyte maturation in vitro and in vivo.

氧苯酮（OBZ）是一种广泛用于防晒霜和化妆品的紫外线过滤剂，是在人类和环境中发现的一种新兴污染物。近期研究表明，在女性的血浆、尿液和母乳中都检测到了OBZ。然而，OBZ暴露对卵母细胞减数分裂的影响尚未得到研究。在本研究中，我们在OBZ暴露的小鼠模型中研究了OBZ对卵母细胞成熟的有害影响以及褪黑素（MT）的保护作用。我们的体外和体内实验结果表明，OBZ抑制卵母细胞成熟，而MT减轻了OBZ诱导的减数分裂缺陷。此外，OBZ通过增加Kdm5基因家族的表达促进H3K4去甲基化，提高活性氧（ROS）水平，降低谷胱甘肽（GSH），损害线粒体质量，并破坏卵母细胞中的纺锤体结构。然而，MT处理在卵母细胞成熟过程中对OBZ诱导的损伤具有显著的保护作用，并提高了卵母细胞质量。MT有益作用的潜在机制包括减轻氧化应激、抑制细胞凋亡、恢复异常的纺锤体组装以及上调H3K4me3。总之，我们的研究结果表明，MT在体外和体内都能保护小鼠卵母细胞成熟过程中免受OBZ诱导的缺陷。