Comparison of the Zebrafish Embryo Toxicity Assay and the General and Behavioral Embryo Toxicity Assay as New Approach Methods for Chemical Screening

Abstract

The movement away from mammalian testing of potential toxicants and new chemical entities has primarily led to cell line testing and protein-based assays. However, these assays may not yet be sufficient to properly characterize the toxic potential of a chemical. The zebrafish embryo model is widely recognized as a potential new approach method for chemical testing that may provide a bridge between cell and protein-based assays and mammalian testing. The Zebrafish Embryo Toxicity (ZET) model is increasingly recognized as a valuable toxicity testing platform. The ZET assay focuses on the early stages of embryo development and is considered a more humane model compared to adult zebrafish testing. A complementary model has been developed that exposes larvae to toxicants at a later time point during development where body patterning has already been established. Here we compare the toxicity profiles of 20 compounds for this General and Behavioral Toxicity (GBT) assay to the ZET assay. The results show partially overlapping toxicity profiles along with unique information provided by each assay. It appears from this work that these two assays applied together can strengthen the use of zebrafish embryos/larvae as standard toxicity testing models.

Linking biochemical and individual-level effects of chlorpyrifos, triphenyl phosphate, and bisphenol A on sea urchin (Paracentrotus lividus) larvae

“…The EC 10 and EC 50 values for larval growth obtained in the present study agree with previous research carried out with sea urchin embryos for CPF (Bellas et al 2005 ; Buono et al 2012 ) and BPA (Kiyomoto et al 2006 ; Özlem and Hatice 2008 ; Tato et al 2018 ), reporting effects at similar concentrations than those reported here. However, no information is available on the toxicity of TPHP on sea urchin embryos and limited toxicological information has been obtained on early stages of aquatic organisms, mainly on zebrafish ( Danio rerio ), reporting effects within the range of 40–29,600 μg/l (geometric mean: 650 μg/l) (e.g., Isales et al 2015 ; Jarema et al 2015 ; Achenbach et al 2020 ). These effect concentrations are, in general, higher than concentrations detected in seawater for these substances (usually < 0.5 μg/l) (Campillo et al 2013 ; Liu et al 2018 ; Salgueiro-González et al 2019 ), although higher concentrations can be present close to main pollution sources or, in the case of plastic additives, close to high plastic debris accumulation.…”

Oxidation-derived anticancer potential of sumanene–ferrocene conjugates

“…The use of zebrafish embryos is one of the most attractive, leading toxicology models in this field, and it constitutes a suitable alternative for the use of small laboratory animals, such as rats or mice, due to short analysis times, short life cycle and transparency of embryos, and, importantly, zebrafish share approximately seventy percent protein-coding genes with humans. [63][64][65] Thus, zebrafish (Danio rerio) teratogenicity assays are commonly used for the prediction of the embryotoxic effects of chemicals, including new drug candidates. The images of zebrafish (Danio rerio) embryos treated with and without the compound 7 are presented in Fig.…”

In Vitro and In Vivo Effects of Ulvan Polysaccharides from Ulva rigida

“…Polysaccharide extracts have also been tested on living organisms, for example, on zebrafish embryos, in the so-called zebrafish embryo toxicity test (ZFET) [ 25 ]. Zebrafish have become an alternative model to rodent toxicity in in vivo assays [ 26 , 27 , 28 ]. This model provides important features, namely, rapid external embryonic development, a small size, optical transparency, a large number of offspring, and genetic similarities to humans [ 29 , 30 ].…”