Nodularin

Nodularin is a potent inhibitor of protein phosphatases types 1 and 2A. Tumor promoter in experimental animal model. At higher doses, causes massive liver hemorrhage. Tumor-promoting effect is due to increasing oxidative stress, as evidenced by reduced levels of glutathione and appearance of oxidative damage in DNA bases. Nodularin is a cyclic pentapeptide toxin produced by the cyanobacteria Nodularia spumigena.Nodularin has been used to induce oxidative stress and analyse its dynamics in flounder liver. It has also been used as standard for identification and quantification by high performan ce liquid chromatography (HPLC).