Preclinical assessment of Cascabela thevetia fruits on developmental toxicity and behavioral safety in zebrafish embryos

Cascabela thevetia (L.) Lippold (Apocynaceae) is an ornamental as well as poisonous plant which has antibacterial, antimicrobial, anti-inflammatory properties. The present study investigated the attenuating effects of the methanol extract of Cascabela thevetia fruits (MECT) on developmental toxicity and behavioral safety in zebrafish embryos. Healthy zebrafish eggs were selected by microscopic screening to study developmental toxicity and behavioral safety starting from 24 h post fertilization (hpf) up to 72 hpf. The zebrafish embryos were exposed in vivo to different concentrations (50, 100 and 200 μg/mL) of MECT. Developmental and morphological abnormalities pertaining to heart, notochord, head, eyes and pigments were recorded in the MECT treated embryos. Increase in heart rate, defective notochord, edema in the head, improperly placed eyes, and absence of pigments were observed with the increasing dose of MECT. The LC50 of the extract was determined based on observations from 1 hpf to 72 hpf and the value is 1000 mg/mL. Inconsistency in the above parameters with change in the dose of MECT corroborates to its toxic potential.