Developmental effects of amoxicillin at environmentally relevant concentration using zebrafish embryotoxicity test (ZET).

Abstract

Amoxicillin (AMX) is an antibiotic that has been added to the watch list of substances by the Euro- pean Union, through the Water Framework Directive (WFD; 2000/60/EC) and its daughter regulation (Deci- sion 2018/840) for which monitoring data have to be gathered with a possibility for future regulation. Previ- ous studies have demonstrated that this antibiotic gen- erates toxic effects, among which oxidative stress in aquatic organisms is noteworthy. The aim of this study was to evaluate the effect on embryonic development and the teratogenic effects induced by AMX at environ- mentally relevant concentrations in oocytes and embry- os of Danio rerio. Furthermore, oxidative stress bio- markers were evaluated at 72 and 96 hpf. The LC50 was 14.192 μgL−1, EC50 was 7.083 μgL−1, and TI was 2.003. Biomarkers of cellular oxidation and antioxidant enzymes were modified in a concentration-dependent way with respect to the control group (p<0.05). The main malformations identified were tail malformation, pericardial edema, yolk sac malformation, scoliosis, pectoral fin absence, and no hatching. The results allow us to conclude that AMX at environmentally relevant concentrations is capable of inducing embryotoxic and teratogenic effects and oxidative damage. This com- pound represents a risk to aquatic organisms such as Danio rerio.