Toxic effects and comparison of common amino antioxidants (AAOs) in the environment on zebrafish: A comprehensive analysis based on cells, embryos, and adult fish

The ubiquity of amino antioxidants (AAOs) in the environment has attracted increasing attention, given their potential toxicity. This investigation represents a pioneering effort, systematically scrutinizing the toxicological effects of four distinct AAOs across the developmental spectrum of zebrafish, encompassing embryonic, larvae, and adult stages. The results indicate that four types of AAO exhibit varying degrees of cell proliferation toxicity. Although environmentally relevant concentrations of AAOs exhibit a comparatively circumscribed impact on zebrafish embryo development, heightened concentrations (300 μg/L) of N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD) and N-isopropyl-N′-phenyl-p-phenylenediamine (IPPD) distinctly evoke developmental toxicity. Behavioral analysis results indicate that at concentrations of 20 and 300 μg/L, the majority of AAOs significantly reduced the swimming speed and activity of larvae. Moreover, each AAO triggers the generation of reactive oxygen species (ROS) in larvae, instigating diverse levels of oxidative stress. The study delineates parallel toxicological patterns in zebrafish exposed to 300 μg/L of 6PPD and IPPD, thereby establishing a comparable toxicity profile. The comprehensive toxicity effects among the four AAOs is as follows: IPPD >6PPD > N-Phenyl-1-naphthylamine (PANA) > diphenylamine (DPA). These findings not only enrich our comprehension of the potential hazards associated with AAOs but also provide data support for structure-based toxicity prediction models.