The objective of this study was to investigate the effects of co-exposure of
iron and
microplastics (MPs) on the cognitive function of aged humans and animals. It was already known that individual
iron or MPs exposure can initiate potential neurotoxicity. However, the combined effect of MPs and
iron remained to be elucidated. In this study, the toxicity of
iron, MPs, co-treatment of MPs &
iron, and the underlying mechanisms were evaluated in vivo. Our findings suggest that 5 µm MPs could enter the aging mice brain and accumulate in cortex and hippocampus. In addition, MPs and
iron have a good binding ability, therefore, co-exposure of MPs &
iron cause significant
iron overload and cognitive deficits as compared to control and individual treatments of
iron and MPs. Moreover, the lipid peroxidation and
inflammation, which are involved in ferroptosis, get significantly elevated by co-exposure of
iron and MPs. Taken together, our results provide compelling evidence that co-exposure of
iron and MPs could aggravate the
cognitive impairment via disturbing brain
iron homeostasis and inducing ferroptosis in cognitive-related brain areas, what's more, the results warn that MPs may act as vectors of
pollutants (mostly
heavy metals) increasing the health burden on body.