Histopathological and biochemical effects of heteroatomic polycyclic aromatic hydrocarbons (Dibenzothiophene and 1-Nitropyrene) in the nerite snail Vitta zebra.

Sulfur- and nitrogen-derived polycyclic aromatic hydrocarbons (S- and N-PAHs) are a group of substances with little toxicological knowledge, but emerging in environmental samples. Thus, this study aimed to first evaluate the effects of exposure to dibenzothiophene (DBT) and 1-nitropyrene (1-NP) on antioxidant defense, oxidative damage, and histopathological markers in nerite snails (Vitta zebra). The animals were exposed to DBT and 1-NP at concentrations of 10, 50, and 100 μg/L and dissected to assess reduced glutathione (GSH) and the activity of glutamate-cysteine ligase (GCL), glutathione peroxidase(GPx), glutathione reductase (GR), and glutathione S-transferase(GST), as well as lipid peroxidation (LPO), in the visceral mass and muscular foot, and to analyze the tissue integrity of the digestive gland. Biochemical analysis showed no significant differences in tissues. However, exposure to both HPAs, regardless of concentration, revealed tissue alterations in the digestive glands, with prevalence of hypertrophy and hyperplasia in digestive cells, tubular atrophy, and degenerative areas suggesting necrosis. In conclusion, the results demonstrate the toxic potential of DBT and 1-NP in V. zebra at the tissue level, probably by the activation of mechanisms distinct from redox metabolism, which highlights the potential risk of these contaminants in the aquatic environment.