Role of oxidative stress and mitochondrial changes in cyanobacteria-induced apoptosis and hepatotoxicity

Microcystins produced by cyanobacteria are potent and specific hepatotoxins however, the mechanisms of microcystin-induced hepatotoxicity have not been fully elucidated. The induction of free radical formation and mitochondrial alterations are two major events found in microcystin-treated cultured rat hepatocytes. The mitochondrial alterations, i.e. loss of mitochondrial membrane potential and mitochondria permeability transition are now recognized as key steps in apoptosis. The activation of calpain and Ca2+/calmodulin-dependent protein kinase 11 is believed to be critical in the microcystin-induced apoptotic process. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.