Hemotoxic activity of jellyfish venom

Abstract

Jellyfish are marine invertebrates of the phylum Cnidaria. All jellyfish species are venomous. Human victims of jellyfish sting each year are 120 million. However, most victims do not require hospitalization. Severe cases of envenomation may sometimes be fatal. Among the symptoms of envenomation, hemotoxicity constitutes a small fraction. Hemolysis has been reported in severe envenomation cases. On the other hand, coagulopathy in jellyfish envenomation is almost absent in scientific literature. Some hemolytic pore- forming toxins have been isolated from venom and tentacle extracts of a few jellyfish species. These toxins show some degree of variation in size and structure. However, many of them cause hemolysis by disturbing the transmembrane ion concentrations. It is also claimed that lipid peroxidation in the membrane is another mechanism of hemolysis. There is no report on anticoagulant or procoagulant toxins isolated from jellyfish venom, although strong fibrinogenolytic and platelet-inhibiting activities have been shown in the tentacle extracts of moon jellyfish. Isolation and characterization of hemolytic and anticoagulant toxins from marine venoms is expected to provide novel molecules of therapeutic interest.