Toxic potential of palytoxin.

Abstract

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.

• Authors: Jiří Patocka, Ramesh C Gupta, Qing-Hua Wu, Kamil Kuca
• Journal: Journal of Huazhong University of Science and Technology. Medical sciences = Hua zhong ke ji da xue xue bao. Yi xue Ying De wen ban = Huazhong keji daxue xuebao. Yixue Yingdewen ban (J Huazhong Univ Sci Technolog Med Sci) Vol. 35 Issue 5 Pg. 773-780 (Oct 2015) ISSN: 1993-1352 [Electronic] China
• PMID: 26489638 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Review)

Chemical References

• Acrylamides
• Cnidarian Venoms
• Marine Toxins
• Sodium-Potassium-Exchanging ATPase
• palytoxin

Topics

• Acrylamides (chemistry, isolation & purification, toxicity)
• Animals
• Anthozoa (pathogenicity, physiology)
• Cnidarian Venoms
• Dinoflagellida (pathogenicity, physiology)
• Dogs
• Guinea Pigs
• Haplorhini
• Humans
• Lethal Dose 50
• Marine Toxins (chemistry, isolation & purification, toxicity)
• Mice
• Rabbits
• Rats
• Seaweed (pathogenicity, physiology)
• Shellfish Poisoning (physiopathology)
• Sodium-Potassium-Exchanging ATPase (metabolism)