Sea anemones as a source of new biologically active substances

Abstract

Sea anemones, as members of Cnidaria, share a very distinctive feature of this phyllum, the presence of nematocysts, which are in part responsible for the toxicity of these marine organisms. Many different peptide toxins that specifically bind with high potency to a variety of ion channels have been obtained from sea anemones; thus contributing considerably to the knowledge of ion channels structure and function. The so called “site 3 toxins” have been the most extensively studied, comprising a structurally diverse group of sea anemone peptides that bind to voltage-gated sodium channels leading to a slowing down of the inactivation process. In subsequent years, several peptide toxins targeting voltage-gated potassium channels toxins from different sources have been also reported. More recently, a new class of sea anemone toxins was discovered, so far solely represented by one peptide capable of binding to acid-sensing ion channels (ASICs). In Cuba, the study of sea anemone toxins began in the 80’s; and up to date the most extensively explored species have been Stichodactyla helianthus, Bunodosoma granulifera, Condylactis gigantea, Phyllactis flosculifera and Epicystis crucifer. Pore-forming toxins, phospholipases, protease inhibitors, K⁺ channels toxins, Na⁺ channels toxins as well as other neurotoxins, showing dissimilar pharmacological effects, have been isolated from these organisms. These studies have contributed to the developing studies of the Cuban biodiversity and also have brought new elements to the knowledge on the potential use of sea anemones. Given their chemical and pharmacological properties, these sea anemone peptides will continue being important pharmacological tools for the analysis of different processes at the molecular level, and presumably they will become promising compounds for the development of new drugs of medical application.