Toxicity evaluation and mechanism study of butylparaben on zebrafish.

Butylparaben is a widely used preservative, yet its toxicity and mechanisms of action in aquatic organisms remain unclear. In this study, zebrafish were used as a model and exposed to butylparaben at concentrations of 0, 1, 1.5, and 2 mg/L from 10 to 72 hpf. The results showed that butylparaben induced developmental malformations in larvae and exhibited stronger toxicity than other parabens of the same family. It significantly reduced the number of innate immune cells and triggered oxidative stress and apoptosis, while astaxanthin, BML-284, and QNZ partially rescued the reduction in neutrophils. In addition, tail curvature was not directly caused by morphological damage to the muscle or notochord. This study demonstrates that butylparaben exerts developmental and immunotoxic effects in zebrafish, providing experimental evidence for the environmental safety assessment of this class of preservatives.