In vivo study reveals dose-dependent genotoxicity and tissue damage from oral micro- and nanoplastics in female rats, suggesting enhanced risk from combined exposure.
Key Points
To evaluate the acute genotoxic hazards, organ toxicity, and oxidative stress pathways associated with oral exposure to polystyrene microplastics, nanoplastics, and their combination in female rats.
Administered oral doses of polystyrene microplastics (1422 nm), nanoplastics (112.3 nm), or their combination at 10, 100, and 1000 mg/kg body weight to female Wistar albino rats.
Evaluated histological tissue damage in the liver and kidneys alongside DNA strand breaks via comet assay in peripheral blood leukocytes, bone marrow, liver, and kidney cells.
Assessed cell cycle phase distributions and quantified plasma redox markers, specifically thiobarbituric acid reactive substances (TBARS) and reduced glutathione.
Histopathology showed dose-dependent hepatic and renal injury that peaked at 1000 mg/kg, with the overall toxicity ranking as MPs+NPs > NPs > MPs.
Comet assays demonstrated significant DNA damage across blood, bone marrow, liver, and kidney cells, with the combined MPs+NPs treatment inducing genotoxicity even at the lowest tested dose (10 mg/kg).
Treatments prompted cell cycle arrest across G0/G1, S, and G2/M phases and caused dose-dependent increases in plasma TBARS alongside reduced glutathione depletion.