Biological activity of sea anemone proteins: I. Toxicity and histopathology.

The crude as well as partially purified protein fractions from anemone species viz. Heteractis magnifica, Stichodactyla haddoni and Paracodylactis sinensis, collected from the Gulf of Mannar, south east coast of India were found to be toxic at different levels to mice. The mice showed behavioral changes such as loss of balance, opaque eyes, tonic convulsions, paralysis, micturiction, flexing of muscles, prodding (insensitive to stimulii), foaming from mouth and exophthalmia. The toxic proteins upon envenomation produced several chronic and lethal histopathological changes like formation of pycnotic nuclii and glial nodules in the brain; heamolysis, thrombosis and myocardial haemorrhage in the heart; granulomatous lesions, and damage to the hepatic cells in the liver and haemorrhage throughout the kidney parenchyma and shrinkage of glomerular tufts in the kidney. The toxins proved to be neurotoxic, cardiotoxic, nephrotoxic and hepatotoxic by their action on internal organ systems. The toxins were also thermostable till 60 degrees C and had considerable shelf life.

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.