Embryotoxicity Evaluation of Novel Synthetic Cannabinoid 4F‐MDMB‐BUTICA Using Zebrafish Embryos

Detailed studies on the embryotoxic and teratogenic effects of synthetic cannabinoids known to be abused are very limited. The present study aimed to evalutate the possible embryotoxic, teratogenic, behavioral, and molecular effects of 4F-MDMB-BUTICA, a new generation synthetic cannabinoid, using zebrafish embryos. The zebrafish embryos were exposed to the cannabinoid at 0.15, 0.30, 0.60, 1.20, 2.40, and 4.80 mg/L from 3 to 24 hpf (acute) and 3 to 120 hpf (subacute). No developmental abnormalities and mortality were observed in embryos after acute exposure. Subacute 4F-MDMB-BUTICA exposure induced mortality of the embryos with the 120 hpf LC₅₀ and EC₅₀ of 1.932 and 0.960 mg/L, respectively. 4F-MDMB-BUTICA also caused embryonic deformities, including spine formation, pericardial edema, impaired blood flow, yolk sac edema, and delayed development. Additionally, subacute cannabinoid exposure induced hypoactivity in response to the stimulus in 120-hpf larvae. qPCR analyses were performed on a subset of 19 genes associated with specific adverse outcomes. The cannabinoid exposure altered the transcriptional expression levels of apoptosis (casp3a, casp8, ifng1, and tp53) DNA repair (rad51), dopamine (dat, drd1, and drd3), serotonin (5ht1aa, 5ht1a, 5ht1b, and 5ht2c), γ-aminobutyric acid (gabra1, gat1, abat, and gad1b), and behavior (gnrh3, gnrhr3, and kiss2)-related genes. In conclusion, the subacute exposure to 4F-MDMB-BUTICA induces mortality, developmental toxicity, hypoactivity of larval behavior, and changes in some essential genes in zebrafish. These findings suggest that 4F-MDMB-BUTICA may have similar embryotoxic effects in humans.