Ibuprofen: Fish Short-Term Reproduction Assay with Zebrafish (Danio rerio) Based on an Extended OECD 229 Protocol.

A study was conducted to understand the potential for ibuprofen to impact the hypothalamus-pituitary-gonadal endocrine axis resulting in disruption of fish reproduction. The Good Laboratory Practice study was conducted according to the Organisation for Economic Co-operation and Development 229 Protocol, Fish Short-Term Reproduction Assay, and extended an additional 4 d to evaluate hatching success in the F1 generation. Test organisms were exposed to nominal test concentrations of 0.5, 2.4, 11.5, 55.3, and 265.4 µg ibuprofen/L and a negative control (dilution water). To strengthen the statistical power of the study, twice the number of replicates were used in the negative control versus individual treatment levels. A 21-d pre-exposure to identify groups of actively spawning fish was immediately followed by a 36-d exposure. Results for apical endpoints of survival, growth, and reproduction (fecundity and fertility), as well as the biomarker vitellogenin in the F0 generation and time to hatch and hatching success in the F1 generation are presented. Based on mean measured exposure concentrations and effects on fecundity in the F0 generation and hatching success in the F1 generation, overall no-observed-effect concentration and lowest-observed-effect concentration for the present study were 55.2 and 265.9 µg ibuprofen/L, respectively. Results from the present study indicate a lack of endocrine-mediated reproductive effects in zebrafish at environmentally relevant concentrations of ibuprofen. Environ Toxicol Chem 2020;39:1534-1545.