Wang Qianqian

Cardiovascular Effect Is Independent of Hemolytic Toxicity of Tentacle-Only Extract from the Jellyfish Cyanea capillata

Our previous studies have confirmed that the crude tentacle-only extract (cTOE) from the jellyfish Cyanea capillata (Cyaneidae) exhibits hemolytic and cardiovascular toxicities simultaneously. So, it is quite difficult to discern the underlying active component responsible for heart injury caused by cTOE. The inactivation of the hemolytic toxicity from cTOE accompanied with a removal of plenty of precipitates would facilitate the separation of cardiovascular component and the investigation of its cardiovascular injury mechanism. In our research, after the treatment of one-step alkaline denaturation followed by twice dialysis, the protein concentration of the treated tentacle-only extract (tTOE) was about 1/3 of cTOE, and SDS-PAGE showed smaller numbers and lower density of protein bands in tTOE. The hemolytic toxicity of tTOE was completely lost while its cardiovascular toxicity was well retained. The observations of cardiac function, histopathology and ultrastructural pathology all support tTOE with significant cardiovascular toxicity. Blood gas indexes and electrolytes changed far less by tTOE than those by cTOE, though still with significant difference from normal. In summary, the cardiovascular toxicity of cTOE can exist independently of the hemolytic toxicity and tTOE can be employed as a better venom sample for further purification and mechanism research on the jellyfish cardiovascular toxic proteins.

Direct cardiac toxicity of the tentacle-only extract from the jellyfish Cyanea capillata demonstrated in isolated rat heart.

Abstract: Previous studies in our laboratory have shown that the cardiotoxicity is the main reason for rat death caused by tentacle-only extract from jellyfish Cyanea capillata. However, the direct cardiotoxicity in vitro and its mechanisms of toxic action remain unclear. The current studies were performed by using the Langendorff-perfused isolated heart model, which showed a dose-dependent hemodynamic and electrocardiogram changes. Heart injury–related enzymes increased. Histopathological analysis showed early ischemic damage in the myocardium. The Ca2+ channel blockers nifedipine and verapamil led to a marked improvement in recovery of cardiac function, including heart rate, left ventricular developed pressure, positive and negative first derivatives of intraventricular pressure, coronary flow, left ventricular end-diastolic pressure, and electrocardiogram changes. Tentacle-only extract–induced cardiac dysfunction could be partly improved by the pretreatments of both propranolol and phentolamine, but not by either atropine or neostigmine at all. In conclusion, we have verified the direct cardiotoxicity of tentacle-only extract from jellyfish C. capillata by the Langendorff isolated heart model, which consisted of 3 separate parts: sinoatrial node malfunction, cardiomyocyte injury, and coronary spasm. The potential mechanism might be attributed to the overactivation of L-type Ca2+ channel, &bgr;- and &agr;-adrenergic receptors, but not cholinergic receptors.

Effect of various cations on hemolytic activity of tentacle-only extract from jellyfish Cyanea capillata

Objective To investigate the potential role of the pore-formation in the hemolytic activity of tentacle-only extract(TOE) from the jellyfish Cyanea capillata.Methods The effects of various cations,including K+,Ca2+,Mg2+,Mn2+,Zn2+,Cu2+,Fe2+,La3+and NH4+ on the hemolytic activity of TOE were compared in two different test systems: 1% whole blood and 0.45% erythrocyte suspension with the same erythrocyte concentration.Results The hemolytic activities of TOE in both tests were inhibited by Mn2+,Zn2+,La3+,Cu2+ and Fe2+,and were promoted to a minor extent by K+,Ca2+,Mg2+ and NH4+.The chelating agent EDTA also inhibited the hemolytic activity of TOE.Conclusion The pore-formation mechanism might play an important role in the hemolytic activity of TOE.