MÚLTIPLOS ENDPOINTS DA TOXICIDADE DO BIOMICROPLÁSTICO DE ÁCIDO POLILÁTICO EM ADULTOS DE ZEBRAFISH (Danio rerio)

Abstract

Studies have reported the toxicity of conventional microplastics (i.e., petroleum derivatives) in different organisms and encouraged the production of alternative materials to replace their use, such as bioplastics. However, the knowledge of the effects of these biopolymers on aquatic vertebrates is still incipient. Thus, the aim of the present study was to test the hypothesis that Danio rerio adults exposed (for 30 days) to polylactic acid biomicroplastics (PLA BioMPs) would accumulate, culminating in behavioral / neurotoxic, biochemical and morphological changes. Our results show that the PLA BioMPs (in concentrations of 2.5 and 5 mg / L) accumulated in the liver, brain, gills and carcass of the animals. However, such accumulation was not able to cause locomotor damage, nor the triggering of anxiety-like behavior in animals. On the other hand, it was enough to cause behavioral changes predictive of deficits in co-specific social interactions and anti-predatory defensive responses, probably related to cholinergic changes (inferred by the increase in acetylcholinesterase) and to a REDOX imbalance, characterized by increased production of reactive species, whose antioxidant system was not able to counterbalance. In addition, we observed that the treatments affected the pigmentation pattern of the animals. Thus, our study shows the toxicological potential of the studied biopolymer, which puts the safety of these materials in check compared to conventional microplastics. However, given the pioneering nature of our study, we emphasize that future research will be useful to broaden our understanding of how these materials affect freshwater ichthyofauna, as well as to assess the magnitude of the ecological risks of these materials in aquatic ecosystems.