Single essential oils and their binary mixtures protect against ethanol-induced defects in a zebrafish fetal alcohol spectrum disorder model at the same level as folic acid.

This study evaluated protective effects of clove (SEO), thyme white (TEO), oregano (OEO), and caraway (CEO) essential oils (EOs), and their binary mixtures, in a zebrafish fetal alcohol spectrum disorder model. Furthermore, folic acid (FA) was used for comparison as it had previously shown protection against ethanol (EtOH)-induced defects. The co-exposure of zebrafish embryos to EtOH (150 mM) and FA (75 μM) or EOs and their binary mixtures (0.5-1 mg/L) was carried out during 6 or 22 hours postfertilization (hpf). Different developmental endpoints (epiboly measurement, survival rate at 24 hpf, embryonic developmental progression measurement at 24 hpf, larval development at 48-96 hpf, and hatching rate at 72-96 hpf) were evaluated at 8-96 hpf. EtOH exposure reduced epiboly. Only FA and the SEO + TEO binary mixture protected against these defects, and SEO and TEO single exposure showed partial protection. Therefore, these groups were chosen for subsequent experiments. At 24 hpf, EtOH showed developmental delay and hatching rate was delayed at 72 hpf. FA, SEO, TEO, and SEO + TEO partially protected against these defects. This study supports the conclusion that FA partially protects against EtOH-induced defects. SEO and TEO single exposure partially protect against EtOH-induced defects. However, the binary mixture of SEO + TEO was more effective, showing similar efficacy as FA.