RESUMO
INTRODUCTION: Oxysterols are cholesterol oxidation products and bioactive lipids involved in developmental signalling pathways, embryonic and postembryonic tissue patterning and homeostasis. The embryonic period is a very sensitive window of exposure to bisphenol A (BPA), hence the role of BPA on the levels of oxysterols in the very early stages of zebrafish embryogenesis is a relevant novel field of investigation. OBJECTIVES: To compare the role of BPA on oxysterols levels in zebrafish embryos at 8 and 24 h post fertilization (hpf) with cytochromes P450 (CYPs)-modulating chemicals (carbamazepine, ketoconazole, and hydrogen peroxide). METHODS: Upon a dose range finding, zebrafish embryos were exposed to environmentally relevant (0.04 µM) and toxicological (17.5 µM) BPA concentrations. Seven oxysterols were profiled by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). RESULTS: Similarly to the CYPs-modulating chemicals, BPA caused: i) no significant changes at 8 hpf and ii) a dose-dependent increase of total oxysterols at 24 hpf, with 27-hydroxycholesterol as the most regulated oxysterol. DISCUSSION: In the first day post-fertilization of the zebrafish embryos, the role of BPA alike a CYPs-modulating chemical was confirmed by the similar oxysterol changes observed with the already known CYPs-modulating chemicals.
