On the Chemistry, Toxicology and Genetics of the Cyanobacterial Toxins, Microcystin, Nodularin, Saxitoxin and Cylindrospermopsin

Abstract

The cyanobacteria or “blue-green algae”, as they are commonly termed, comprise a diverse group of oxygenic photosynthetic bacteria that inhabit a wide range of aquatic and terrestrial environments, and display incredible morphological diversity. Many aquatic, bloom-forming species of cyanobacteria are capable of producing biologically active secondary metabolites, which are highly toxic to humans and other animals. From a toxicological viewpoint, the cyanotoxins span four major classes: the neurotoxins, hepatotoxins, cytotoxins, and dermatoxins (irritant toxins). However, structurally they are quite diverse. Over the past decade, the biosynthesis pathways of the four major cyanotoxins: microcystin, nodularin, saxitoxin and cylindrospermopsin, have been genetically and biochemically elucidated. This review provides an overview of these biosynthesis pathways and additionally summarizes the chemistry and toxicology of these remarkable secondary metabolites.

Planktonic and benthic cyanobacteria of European brackish waters: a perspective on estuaries and brackish seas

“…In Europe, toxic N. spumigena blooms have frequently been reported in the Baltic Sea and because of that NOD is considered to be one of the most abundant naturally occurring compounds in this brackish-water environment (Pearson et al, 2010). Production of NOD in situ and in laboratory conditions has been well studied.…”

“…Comprehensive reviews of cyanotoxins in aquatic systems have been published in the last few years (e.g. Van Apeldoorn et al, 2007;Pearson et al, 2010) and so the present review will focus on the one toxin most commonly found and primarily studied in brackish-water and estuarine environments, NOD.…”

“…They comprise peptides, macrolides and glycosides with a broad spectrum of bioactivity, ranging from antifungal, antibacterial, antiviral and cytotoxic to antineoplastic activity (Lehtima¨ki et al, 2000;Welker & Von Do¨hren, 2006). The first report of toxicity induced by cyanobacterial metabolites was published in the late nineteenth century (Francis, 1878) but only in 1950 was lethality induced by cyanotoxins demonstrated in the laboratory (Carmichael, 1994 (Pearson et al, 2010). Some authors consider yet another group of cyanotoxins, the cytotoxins, which are not highly lethal to animals but exhibit more selective bioactivity (Keil et al, 2002;Welker & Von Do¨hren, 2006).…”

“…Cyanobacteria are also known for producing a wide array of secondary metabolites, some being toxic to other organisms and causing poisonings of humans and animals (Carmichael, 1994). According to their effects on mammals, cyanotoxins may be divided into four major groups: (i) neurotoxins, (ii) hepatotoxins, (iii) cytotoxins and (iv) dermatoxins (irritant toxins) (Pearson et al, 2010). The first two can cause acute and sometimes lethal poisonings while cytotoxins are not lethal but show selective bioactivity and dermatoxins are linked mainly with inflammation of the skin (Dow & Swoboda, 2000).…”

Preparation and Photocatalytic Performance of TiO2 Immobilized on Fiberglass Cloth

“…The cyclic hepatotoxic peptides microcystins (MCs) are among the most important and by far themost studied cyanotoxins. This group of toxins can be produced by by a number of cyanobacteria genera such as Microcystis, hjycdq@hhu.edu.cn, hjycyq@hhu.edu.cn) Anabaena, Plankothrix and Nostoc had been proved to be acute hepatotoxicity [17], [18]. Though MCs mainly inhibit the serine/threonine phosphatases (PP1 and PP2A), they may also promote tumor formation, induce apoptosis, and present long-term chronic toxic effects on wildlife, domestic animals and humans [19]- [22].…”