Effects of phthalate acid esters on zebrafish larvae: Development and skeletal morphogenesis

This study evaluated the acute developmental toxicity of six priority phthalic acid esters (PAEs) including dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), di-2-ethylhexyl phthalate (DEHP), di-n-octyl phthalate (DNOP), and benzyl butyl phthalate (BBP) in zebrafish embryos. A novel alcian blue and alizarin red double staining was performed to detect skeletal development of zebrafish larvae. Results revealed that all six PAEs could induce different developmental abnormalities in zebrafish larvae, including abnormal movement, decreased heart rate, spinal curvature, and pericardial edema. The bone development of zebrafish larvae exposed to PAEs was also affected by PAEs acute exposure. Among PAEs, DBP, and BBP even at low doses can cause mortality in zebrafish, implying their higher toxicity. Contrarily, DEHP and DNOP showed minor effects on the developmental morphology of zebrafish larvae. However, the gene expression levels of skeleton-related genes showed the upregulation of the runx2b and shha genes after DEHP and DBP exposure. Taken together, the strict use and release of PAEs in the environment should be supervised by the government for ecological and environmental safety.