Toxic potential of palytoxin.
This review briefly describes the origin, chemistry, molecular mechanism of action, pharmacology, toxicology, and ecotoxicology of palytoxin and its analogues. Palytoxin and its analogues are produced by marine dinoflagellates. Palytoxin is also produced by Zoanthids (i.e. Palythoa), and Cyanobacteria (Trichodesmium). Palytoxin is a very large, non-proteinaceous molecule with a complex chemical structure having both lipophilic and hydrophilic moieties. Palytoxin is one of the most potent marine toxins with an LD50 of 150 ng/kg body weight in mice exposed intravenously. Pharmacological and electrophysiological studies have demonstrated that palytoxin acts as a hemolysin and alters the function of excitable cells through multiple mechanisms of action. Palytoxin selectively binds to Na(+)/K(+)-ATPase with a Kd of 20 pM and transforms the pump into a channel permeable to monovalent cations with a single-channel conductance of 10 pS. This mechanism of action could have multiple effects on cells. Evaluation of palytoxin toxicity using various animal models revealed that palytoxin is an extremely potent neurotoxin following an intravenous, intraperitoneal, intramuscular, subcutaneous or intratracheal route of exposure. Palytoxin also causes non-lethal, yet serious toxic effects following dermal or ocular exposure. Most incidents of palytoxin poisoning have manifested after oral intake of contaminated seafood. Poisonings in humans have also been noted after inhalation, cutaneous/systemic exposures with direct contact of aerosolized seawater during Ostreopsis blooms and/or through maintaining aquaria containing Cnidarian zoanthids. Palytoxin has a strong potential for toxicity in humans and animals, and currently this toxin is of great concern worldwide.
University of South Bohemia Ceske Budejovice, Faculty of Health and Social Studies, Department of Radiology and Toxicology, Ceske Budejovice, 37005, Czech Republic.|Biomedical Research Center, University Hospital, Hradec Kralove, 50003, Czech Republic.
Jiří
J
Patocka
Toxicology Department, Murray State University, Hopkinsville, 42071, USA.
Ramesh C
RC
Gupta
College of Life Science, Yangtze University, Jingzhou, 434025, China. wqh212@hotmail.com.|Faculty of Informatics and Management, University of Hradec Kralove, Hradec Kralove, 50003, Czech Republic. wqh212@hotmail.com.
Qing-Hua
QH
Wu
Biomedical Research Center, University Hospital, Hradec Kralove, 50003, Czech Republic. kamil.kuca@fnhk.cz.|Faculty of Informatics and Management, University of Hradec Kralove, Hradec Kralove, 50003, Czech Republic. kamil.kuca@fnhk.cz.
Kamil
K
Kuca
D000178:Acrylamides / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity*; D000818:Animals; D037421:Anthozoa / Q000472:pathogenicity* / Q000502:physiology; D003064:Cnidarian Venoms; D004141:Dinoflagellida / Q000472:pathogenicity* / Q000502:physiology; D004285:Dogs; D006168:Guinea Pigs; D000882:Haplorhini; D006801:Humans; D007928:Lethal Dose 50; D008387:Marine Toxins / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity*; D051379:Mice; D011817:Rabbits; D051381:Rats; D012624:Seaweed / Q000472:pathogenicity* / Q000502:physiology; D057096:Shellfish Poisoning / Q000503:physiopathology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D000095702:Polyether Toxins
D000178:Acrylamides; D003064:Cnidarian Venoms; D008387:Marine Toxins; D000254:Sodium-Potassium-Exchanging ATPase; C010272:palytoxin; D000095702:Polyether Toxins
dinoflagellate; neurotoxicity; palytoxin; phycotoxin; toxicity