Biological activity of sea anemone proteins: II. Cytolysis and cell line toxicity

Potent cytolytic activity was exhibited by proteins extracted from three sea anemones viz. Heteractis magnifica, Stichodactyla haddoni and Paracodylactis sinensis by affecting the red blood corpuscles (RBC) and the mouse fibroblast cell line (L929) and leukemia cell line (P388). Crude toxin of all the three anemone species induced spontaneous hemolysis of chicken, goat and human erythrocytes. The crude toxin of H. magnifica (0.98 mg/ml) elicited hemolysis at levels of 4096, 512 and 4096 HU (hemolytic unit) in chicken, goat and human erythrocytes respectively. Subsequently, the crude toxin of S. haddoni (0.82 mg/ml) exhibited a hemolytic activity of 256, 128 and 512 HU and that of P. sinensis (0.60 mg/ml) had a hemolytic activity of 128, 4096 and 512 HU. Most of the partially purified proteins of these anemones also exhibited the activity against the three different erythrocytes. The viability of L929 and P388 was adversely affected on adding the crude toxins. The symptoms of toxicity shown by the cells were rounding, lysis and detachment from the substratum. These effects were the least in S. haddoni, as compared to those the crude toxins of the other two species. Inhibition of growth of L929 exhibited by the toxin of the three species ranged between 61.08 and 93.38%. Similarly, inhibition of the growth of P388 ranged between 51.32 and 86.16%. The present investigation reveal the cytotoxic nature of anemone toxins.