Ancient Venom Systems: A Review on Cnidaria Toxins

Abstract

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.

Estudio bioquímico del veneno de la anémona de mar Phymactis papillosa (Actiniidae)

“…Gran parte del interés en estudiar estas proteínas, es encontrar actinoporinas que formen poros específicamente en las membranas de células cancerosas y puedan destruirlas (Jouiaei et al 2015).…”

“…Otro de los componentes característicos de los venenos de anémonas de mar lo constituyen las neurotoxinas, que son péptidos que afectan el funcionamiento de los canales iónicos de sodio y de potasio de las membranas celulares de neuronas y células musculares, y cuyo bloqueo daña el sistema nervioso central (Jouiaei et al 2015). Éstos péptidos, por su especificidad, pueden ser utilizados en estudios de estructura y función de canales iónicos.…”

Aporte al conocimiento de las medusas (Cnidaria: Medusozoa) en el departamento del Atlántico, Colombia

“…Se conoce que más de 1.000 especies son tóxicas, y el contacto con ellas puede originar inmediatamente ronchas, vesículas dolorosas y pruriginosas con sensación urente, además de eritema y edema cutáneos, que rara vez llegan a la necrosis y el colapso cardiorrespiratorio (Auerbach, 1991;Vera, et al, 2004;Otero, 2012;Jouiaei, et al, 2015). Cuando suceden estas proliferaciones, las autoridades costeras tienden a restringir el acceso a las playas para evitar cualquier incidente (Boero, 2013).…”

Evolution and diversification of the cnidarian venom system

“…It can be hypothesised that as a member of the venom proteome which is presumably injected during a sting, serine protease inhibitors could contribute to the symptoms of envenomating by inhibiting the rapid degradation of the venom protease by endogenous enzymes of the animals themselves or of the prey [279]. Neurotoxic [40,248], inhibition of Ca release [251], anti platelet [249], hemolytic [250], allergen [252], apoptotic cell death [253] Astasin-like proteins with toxic activity are recruited in the venom from spiders of the genus…”

“…Amongst these animals are sea anemones, a group of predatory animals of the phylum Cnidaria, class Anthozoa. Although the majority of the sea anemones are harmless to human, few species are highly toxic producing a venomous cocktail that can cause severe neurotoxic, cytotoxic and hemolytic effects [279]. In spite of this, the biodiversity and the remarkable pharmacological properties of venom can be a valuable bioresource of potential drug candidates [73,219].…”