Toxicity of the cardiotoxic protein, flammutoxin, isolated from the edible mushroom Flammunlina velutipes

Flammutoxin is a cardiotoxic protein which has been purified from the edible mushroom, Flammulina velutipes. The protein has strong hemolytic activity against human group O red blood cells and calcium ions at physiological concentration can partially reverse the hemolytic effect. The inhibitory effect of the toxic protein on the respiration of Ehrlich ascites tumor cells was also suppressed by calcium ions. When the toxic protein was injected i.p. into mice, it caused the writhing reaction which was partially inhibited by antihistaminics. When the toxic protein was locally injected into rat paws, it induced severe edema.