Cnidarians are the oldest extant lineage of venomous animals. Despite their

simple anatomy, they are capable of subduing or repelling prey and predator species that are

far more complex and recently evolved. Utilizing specialized penetrating nematocysts,

cnidarians inject the nematocyst content or “venom” that initiates toxic and immunological

reactions in the envenomated organism. These venoms contain enzymes, potent pore

forming toxins, and neurotoxins. Enzymes include lipolytic and proteolytic proteins that

catabolize prey tissues. Cnidarian pore forming toxins self-assemble to form robust

membrane pores that can cause cell death via osmotic lysis. Neurotoxins exhibit rapid ion

channel specific activities. In addition, certain cnidarian venoms contain or induce the

release of host vasodilatory biogenic amines such as serotonin, histamine, bunodosine and

caissarone accelerating the pathogenic effects of other venom enzymes and porins. The

cnidarian attacking/defending mechanism is fast and efficient, and massive envenomation

of humans may result in death, in some cases within a few minutes to an hour after sting.

The complexity of venom components represents a unique therapeutic challenge and probably

reflects the ancient evolutionary history of the cnidarian venom system. Thus, they are

invaluable as a therapeutic target for sting treatment or as lead compounds for drug design.