Diesel exhaust particles induce lasting and age-dependent damage to the brain in Drosophila melanogaster

Diesel exhaust particles (DEP), major air pollutants emitted from automobile engines, contain numerous toxic compounds. While the adverse effects of DEP exposure on the respiratory and cardiovascular systems are well documented, its impact on brain health remains poorly understood. In this study, we employed Drosophila melanogaster as a model organism to investigate the neurological effects of DEP exposure and the impact of exposure cessation across different age groups. Molecular, histopathological, and behavioral markers were assessed before and after exposure to varying doses of DEP at different time intervals. Interestingly, DEP exposure induced age-dependent cellular responses in the brain, including elevated reactive oxygen species (ROS), increased neuroinflammation, and disruption of the blood-brain barrier (BBB). Prolonged exposure led to pronounced vacuolization in the brains of aged flies. While cessation of DEP exposure resulted in partial recovery in young flies particularly when implemented early, aged flies exhibited limited benefit, with persistent evidence of likely irreversible brain damage. Overall, this study invites greater public awareness and careful consideration in public health policy to limit long-term DEP exposure, particularly among older individuals, and to encourage strategies that reduce potential risks to brain health associated with air pollution.