Polystyrene nanoplastics induced oxidative stress and antioxidant defence in the digestive tissues of a freshwater pulmonate snail, Indoplanorbis exustus

Polystyrene nanoplastics (PS-NPs) are emerging contaminants that pose a threat to aquatic organisms, especially filter-feeding species such as snails. The ingestion of PS-NPs by snails results in the induction of oxidative stress within their digestive tissues, resulting in a sudden increase in reactive oxygen species (ROS). The present study investigated the impact of polystyrene nanoparticle exposure on ROS generation and antioxidant defense in the digestive tissues of the freshwater pulmonate snail, Indoplanorbis exustus . This outcome demonstrates that the induction of target tissues by PS-NPs significantly elevates ROS levels in a time-dependent manner, triggering the adaptive antioxidant system, including glutathione, superoxide dismutase, and catalase, to respond accordingly. The increase in ROS levels suggests a disruption of cellular homeostasis, which helps in the mollusc’s natural defense mechanisms. This sudden increase in the ROS level in the tested tissue is reduced by the deployment of the antioxidant enzymes. However, prolonged exposure to PS-NPs results in the depletion of antioxidant reserves, which potentially compromises the digestive system and exacerbates oxidative damage in the tissue. The present study highlights the role of polystyrene in disrupting the balance in the digestive system of the freshwater pulmonate snail, I. exustus, as well as raising the long-term potential health consequences of nanoparticle pollution on aquatic organisms. Further studies are required to elucidate the broader impact of polystyrene NP-induced oxidative stress on sentinel species and the ecological consequences of widespread plastic contamination in aquatic environments.