Evaluation of the Toxic effects of Bothrops jararacussu Snake Venom on Zebrafish (Danio rerio) embryos and larvae

Approximately 90% of reported and identified cases of snakebite in Brazil are caused by species belonging to the Bothrops genus. These snakes have clinical relevance due to their venom composition, which contains substances capable of triggering local and systemic effects culminating in the development of morbidities and mortality in the affected individual. This study aims to evaluate the toxic and toxinological effects of Bothrops jararacussu snake venom on zebrafish embryos and larvae. B. jararacussu venom’s stability, under the conditions used in the toxicity experiments in zebrafish embryos and larvae was evaluated on citrated human plasma by measuring the prothrombin and activated partial thromboplastin times. Mortality, morphological alterations, spontaneous tail movements, heartbeat, toxicity parameters and activity of enzymes biomarkers of toxicity were evaluated in zebrafish embryos and/or larvae after exposure to the venom. Acute toxicity was assessed by semi-static exposure of zebrafish embryos to venom for 96 hours. The results indicated that the venom causes toxicity in zebrafish embryos and larvae, inducing embryonic mortality, alteration in the number of spontaneous tail movements and activity of biomarker enzymes. The results suggest that the toxic effects caused by the venom in the early stages of zebrafish development are mediated, in part, by neurotoxic action, and induction of oxidative and metabolic stress caused by low molecular weight components and proteins present in this venom. Toxinological evaluations using the zebrafish as a model are scarce; however, this study presented promising results that encourage the development of future research in toxinology using this animal as a model organism.