Octocrylene exposure impairs mouse oocyte quality by inducing spindle defects and mitochondria dysfunction

One of organic ultraviolet (UV) filters, Octocrylene (OCL), is mainly used in various cosmetic products, which is being frequently detected in soil, sediment, aquatic systems and food chain. There is evidence confirmed the reproductive toxicity of OCL in Japanese medaka. However, less was known about the effects of OCL exposure on oocyte quality. Here, we investigated the impacts of OCL on mouse oocyte maturation and quality by exposing oocytes to OCL in vitro at concentrations of 8, 22, 30, 40 and 50 nM. The results showed that OCL markedly reduced mouse oocyte germinal vesicle breakdown (GVBD) at 50 nM and polar body extrusion (PBE) rates at 40 and 50 nM. OCL exposure further disrupted spindle assembly and chromosome alignment, finally inducing aneuploid. Mitochondrial function was also damaged by OCL exposure, leading to ROS overproduction and apoptosis in oocytes. Moreover, OCL treatment impaired the distribution of cortical granules and sperm binding ability of oocytes. In summary, these data demonstrated that OCL could disturb the oocyte meiotic maturation and reduce oocyte quality.