The cytotoxic effects of metallic nanoparticles (MNPs) might be revealed in genomic and histopathological defects. Therefore current study aimed to assess the bio-persistence and adverse effects potency of zinc oxide nanoparticles (ZnONPs) in the gastropod, Monacha cartusiana. Gastropods were exposed to 74 μg/mL for 14 d then the DNA adduct and histopathological defect profiles were assessed. The results demonstrated significant decline in the estimated genomic template stability (GTS%) in haemolymph and digestive gland ranging from 10.0 to 42.9% in treated animals compared to controls. In the treated and recovered snails, randomly amplified polymorphic (RAPD)-DNA showed the appearance and/or disappearance of DNA bands, indicating DNA damage due to the cytotoxicity of ZnONPs on gastropods. Significant defects in microvilli (MV), nucleus (N), mitochondria (M), and execratory glands (EXG) were noticed in the treated individuals with respect to controls. The remaining live animals were subjected to a recovery period (14 d, without treatment) and slight recovery profiles were reported for both measures compared to the control group. The recovery pattern was recognized in the nucleus/cytoplasm ratio with 0.186 and 0.428 in the treated and recovered groups concerning their control (0.176). The studied parameters reported herein might be reliable tools to assess accumulation and bio-persistence patterns of NPs in the organisms for short-term exposure indicating the cytotoxic and genotoxic effects. Also, gastropods may provide simple models for evaluating the ecotoxicological effects of nanomaterials.
Keywords: DNA adduct; gastropods; histopathological defects; short-term exposure; zinc oxide nanoparticles.