Polystyrene microplastics induced female reproductive toxicity in mice

TLDR

Plastics pollution has led to widespread microplastic contamination, yet the reproductive toxicity of microplastics in female mammals remains poorly understood. The study exposed female mice to polystyrene microplastics for 35 days to assess their reproductive toxicity. Polystyrene microplastics accumulated in multiple organs and triggered ovarian inflammation, oxidative stress, and impaired oocyte quality, as shown by increased IL‑6 and ROS, decreased MDA, GSH, mitochondrial membrane potential, and endoplasmic reticulum Ca²⁺, along with reduced polar‑body extrusion and oocyte survival rates.

Abstract

Plastics have caused serious environmental pollution. In recent years, microplastics (MPs) have caused widespread concern about their potential toxicity on animals and humans, especially on organ and tissue deposition. However, there is little known about the reproductive toxic effects of MPs in female mammals. In this study, the reproductive toxicity of polystyrene MPs (PS-MPs) in female mice was evaluated after continued exposure for 35 days. Results showed that PS-MPs could accumulate in heart, liver, spleen, lung, kidney, brain, large intestine, small intestine, uterus, ovary and blood of exposed mice. Moreover, PS-MPs exposure increased the IL-6 level and decreased malondialdehyde (MDA) level in mouse ovaries. The results also showed that PS-MPs exposure decreased the first polar body extrusion rate and the survival rate of superovulated oocytes. Meanwhile, PS-MPs reduced the level of glutathione (GSH), mitochondrial membrane potential (MMP), endoplasmic reticulum calcium ([Ca2+]ER) and increased reactive oxygen species (ROS) in oocytes. In conclusion, our study illustrated that PS-MPs exposure induced the inflammation of ovaries and reduced the quality of oocytes in mice, which provided a basis for studying the reproductive toxic mechanism of PS-MPs in female mammals.