Biomonitoring genotoxicity and cytotoxicity of Microcystis aeruginosa (Chroococcales, Cyanobacteria) using the Allium cepa test
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
07/11/2013
07/11/2013
2012
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Resumo |
Water pollution caused by toxic cyanobacteria is a problem worldwide, increasing with eutrophication. Due to its biological significance, genotoxicity should be a focus for biomonitoring pollution owing to the increasing complexity of the toxicological environment in which organisms are exposed. Cyanobacteria produce a large number of bioactive compounds, most of which lack toxicological data. Microcystins comprise a class of potent cyclic heptapeptide toxins produced mainly by Microcystis aeruginosa. Other natural products can also be synthesized by cyanobacteria, such as the protease inhibitor, aeruginosin. The hepatotoxicity of microcystins has been well documented, but information on the genotoxic effects of aeruginosins is relatively scarce. In this study, the genotoxicity and ecotoxicity of methanolic extracts from two strains of M. aeruginosa NPLJ-4, containing high levels of microcystin, and M. aeruginosa NPCD-1, with high levels of aeruginosin, were evaluated. Four endpoints, using plant assays in Allium cepa were applied: rootlet growth inhibition, chromosomal aberrations, mitotic divisions, and micronucleus assays. The microcystin content of M. aeruginosa NPLJ-4 was confirmed through ELISA, while M. aeruginosa NPCD-1 did not produce microcystins. The extracts of M. aeruginosa NPLJ-4 were diluted at 0.01, 0.1, 1 and 10 ppb of microcystins: the same procedure was used to dilute M. aeruginosa NPCD-1 used as a parameter for comparison, and water was used as the control. The results demonstrated that both strains inhibited root growth and induced rootlet abnormalities. The strain rich in aeruginosin was more genotoxic, altering the cell cycle, while microcystins were more mitogenic. These findings indicate the need for future research on non-microcystin producing cyanobacterial strains. Understanding the genotoxicity of M. aeruginosa extracts can help determine a possible link between contamination by aquatic cyanobacteria and high risk of primary liver cancer found in some areas as well as establish water level limits for compounds not yet studied. (C) 2012 Elsevier B.V. All rights reserved. State of Sao Paulo Research Foundation [FAPESP 2009/05474-5, 2010/09867-9] CNPq [308299/2009-4, 151931/2010-0] |
Identificador |
SCIENCE OF THE TOTAL ENVIRONMENT, AMSTERDAM, v. 432, n. 3, pp. 180-188, AUG, 2012 0048-9697 http://www.producao.usp.br/handle/BDPI/43323 10.1016/j.scitotenv.2012.05.093 |
Idioma(s) |
eng |
Publicador |
ELSEVIER SCIENCE BV AMSTERDAM |
Relação |
SCIENCE OF THE TOTAL ENVIRONMENT |
Direitos |
closedAccess Copyright ELSEVIER SCIENCE BV |
Palavras-Chave | #GENOTOXICITY #CYTOTOXICITY #CYANOTOXINS #MICROCYSTIS AERUGINOSA #ALLIUM CEPA TEST #DNA-DAMAGE #LR #EXTRACTS #CELLS #HEPATOCYTES #INHIBITION #NODULARIN #TOXINS #ASSAY #L. #ENVIRONMENTAL SCIENCES |
Tipo |
article original article publishedVersion |