Transgenerational neurotoxicity of polystyrene microplastics induced by oxidative stress in Caenorhabditis elegans

Microplastics (MPs), emerging environmental contaminants, exhibit multiple toxicities in organisms. However, the transgenerational neurotoxicity of MPs has received little attention. Caenorhabditis elegans has been used as a model organism for studying transgenerational toxicity. In this study, the transgenerational neurotoxicity and oxidative stress of MPs were investigated over five generations (F0–F4) of C. elegans. The parental generation (F0) was exposed to polystyrene microplastics (PS-MPs) at concentrations of 0.1–100 μg/L, and subsequent generations (F1–F4) were cultured under toxicant-free conditions. The results indicated that exposure to PS-MPs at concentrations of 10–100 μg/L significantly decreased head thrash and body bends in nematodes, and this reduction was also observed in subsequent generations (F1–F2). This suggested that neurotoxicity induced by PS-MPs can be transferred from the parent to subsequent generations. Maternal exposure to 100 μg/L PS-MPs significantly enhanced ROS production and lipofuscin accumulation in subsequent generations (F1–F2), indicating that the induction of oxidative stress plays an important role in the transgenerational neurotoxicity in C. elegans. Moreover, maternal exposure to PS-MPs resulted in the transgenerational upregulation of genes related to oxidative stress (clk-1, ctl-1, sod-3, sod-4, and sod-5) in the F1–F3 generations, which indicated that these genes may be involved in regulating transgenerational neurotoxicity in C. elegans.