Cytotoxicity and Hemolytic Activity of Jellyfish Nemopilema nomurai (Scyphozoa: Rhizostomeae) Venom

Abstract

The recent bloom of a giant jellyfi sh Nemopilema nomurai has caused a danger to sea bathers and fi shery damages in the waters of China, Korea, and Japan. The present study investigated the cytotoxic and hemolytic activities of crude venom extract of N. nomurai using a number of in vitro assays. The jellyfi sh venom showed a much higher cytotoxic activity in H9C2 heart myoblast than in C2C12 skeletal myoblast (LC50 = 2 µg/mL vs. 12 µg/mL, respectively), suggesting its possible in vivo selective toxicity on cardiac tissue. This result is consistent with our previous fi nding that cardiovascular function is a target of the venom. In order to determine the stability of N. nomurai venom, its cytotoxicity was examined under the various temperature and pH conditions. The activity was relatively well retained at low environmental temperature (≤20 °C) and dramatically lost at high temperature (≥60 °C). In pH stability test, the venom has abruptly lost its activity at low pH environment (pH≤4). Interestingly enough, however, its activity was not signifi cantly affected even at the highest pH environment tested (pH≤12) in the present study. Additionally, hemolytic activity of the venom was examined using the erythrocytes of cat, dog, human, rabbit and rat. Venom concentrationdependent hemolysis could be observed from 10 µg/mL of protein equivalents or higher with variable potencies in different species, among which dog erythrocyte was the most susceptible to the venom (EC50 = 151 µg/mL). SDS-PAGE analysis of N. nomurai venom showed the molecules of 20–40 kDa and 10– 15 kDa appeared to be the major protein components of the venom.