Factors influencing hemolytic activity of venom from the jellyfish Rhopilema esculentum Kishinouye

In this study, hemolytic activity of venom from the jellyfish Rhopilema esculentum Kishinouye and some factors affecting it were assayed. The HU50 of R. esculentum full venom (RFV) against chicken erythrocytes was 3.40 μg/ml and a Hill coefficient value was 1.73 suggesting at least two molecules participated in hemolytic activity. The hemolytic activity of RFV was affected by some chemical and physical factors such as divalent cations, EDTA, (NH4)2SO4, pH and temperature. In the presence of Mg2+, Cu2+, Zn2+, Fe2+, Ca2+ (⩾2 mM), Mn2+ (⩾1 mM), EDTA (⩾2 mM) and (NH4)2SO4, the hemolytic activity of RFV was reduced. RFV had strong hemolytic activity at the pH 6–10 and the hemolytic ratios were 0.95–1.19. Hemolytic activity was temperature-sensitive and when RFV was pre-incubated at temperatures over 40 °C, it was sharply reduced.