Nodularins in poisoning

Nodularins are an important class of hepatotoxic cyclic pentapeptides that are produced by the cyanobacteria Nodularia spumigena. These peptides have been found worldwide and have been implicated in the deaths of animals as well as a potent cyanotoxin in humans. To date, approximately 10 variants have been discovered, among which nodularin-R is the most abundant. Though the mechanisms of their potential hepatotoxicity and carcinogenicity are not well understood, the most frequently proposed mechanisms are described here. Most importantly, a comprehensive review of nodularins in poisoning is presented, including their bio-accumulation in water, cyanobacterial blooms and aquatic animals, the IC50, LC50 and LD50 values determined in laboratories, and wild, domestic and laboratory animal cases. However, the hazard of these toxins to humans has not been fully elucidated, predominantly due to the lack of exposure data. One of reasons underlying is that most current methods are ill suited for clinical monitoring. Thus, the available assays for the detection and quantification of nodularins are described with an emphasis on the problems encountered with each assay. Our ultimate aim is to demonstrate the urgency of better understanding the toxicity of nodularins, especially in humans, and thus effectively protecting ourselves from their poisoning. (C) 2013 Elsevier B.V. All rights reserved.