The acute and sub-acute cardiotoxicity effects of the Persian Gulf upside-down jellyfish ‘‘Cassiopea sp. ‘‘venom

Introduction: Cardiovascular toxicities are considered the major toxic effect of some jellyfish venoms. In the present study, crude venom from the Persian Gulf upside-down jellyfish ‘‘Cassiopea sp. for acute and sub-acute cardiotoxicity, were studied.Methods: The acute and sub-acute toxicity of the venom from the alien Cassiopea andromeda jellyfish were studied in rat respectively at 60min and 21 days after exposure. For acute study, direct cardiotoxicity of the venom was assessed by a Langendorff isolated perfused rat heart system. Treatments were performed with concentrations of 50, 20, 10, 5, and 2.5 μg/ml of venom on isolated rat hearts for 60 min. Then, the hemodynamic parameters of heart rate, left ventricular end-diastolic pressure, left ventricular systolic pressure, left ventricular developed pressure, and coronary flow were evaluated. Lactate dehydrogenase (LDH) levels as well as histopathological examinations were also investigated. Moreover, for sub-acute toxicity on the heart, three doses of crude venom (0.0125, 0.025 and 0.05 μg/ml/day) were administered intraperitoneally to the rats, once daily for 21 days.Results: Based on the ECG findings, treatments in a dose-dependent pattern changed cardiac electrical activity and decreased coronary effluent. The higher concentrations of venom produced severe bradycardia, atrioventricular dissociation, complete atrioventricular block, and ultimately cardiac arrest. Ventricular end-diastolic pressure was also significantly increased by high concentrations of venom. At high venom concentrations, scatter lymphocytic infiltration and wavy fibers were found in the histopathological examinations. Treatment with concentrations of 2.5–10 μg/ml caused a considerable increase in LDH levels within 30 min compared with baseline levels. Histopathological examinations of the rat heart tissues indicated that there were different demonstrable abnormalities and alterations in the microscopic examinations in comparison to their control groups, especially at a higher dose of 0.05 μg/ml/dayConclusion: In conclusion, venom from the Persian Gulf upside-down jellyfish had significant direct and sub acute cardiotoxicity effects on isolated rat hearts. The jellyfish crude venom contains compounds that may affect cardiac contraction, heart rate, and blood pressure.

Keywords:

Upside-down Jellyfish , Cassiopea andromeda , Cardiotoxicity , acute , sub-acute , Venom