Biomonitoring genotoxicity and cytotoxicity of Microcystis aeruginosa (Chroococcales, Cyanobacteria) using the Allium cepa test

Autor(es)

Laughinghouse, Haywood Dail ^[1] ; Pra, Daniel ^{[1, 2, 3]} ; Silva-Stenico, Maria Estela ^[4] ; Rieger, Alexandre ^[1] ; Frescura, Viviane Dal-Souto ^[5] ; Fiore, Marli Fatima ^[4] ; Tedesco, Solange Bosio ^{[5, 6]}

Afiliação do(s) autor(es)

^[1] Univ Santa Cruz do Sul, Dept Biol & Pharm, Lab Biotechnol & Genet, Santa Cruz Do Sul, RS - Brazil

^[2] Univ Catolica Pelotas, Ctr Life & Hlth Sci, Lab Genet & Neurosci, Pelotas, RS - Brazil

^[3] Univ Santa Cruz do Sul, Grad Course Hlth Promot, Santa Cruz Do Sul, RS - Brazil

^[4] Univ Sao Paulo, Ctr Nucl Energy Agr, Lab Mol Ecol Cyanobacteria, Piracicaba, SP - Brazil

^[5] Univ Fed Santa Maria, Agrobiol Grad Program, Santa Maria, RS - Brazil

^[6] Univ Fed Santa Maria, Dept Biol, Lab Plant Cytogenet & Genotox, Santa Maria, RS - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Science of The Total Environment; v. 432, p. 180-188, AUG 15 2012.
• Citações Web of Science: 28

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. (AU)

• Processo FAPESP: 09/05474-5 - Bioprospecção de cianobactéria: seleção de cianopeptídeos para aplicação farmacêutica e biotecnológica
• Beneficiário: Maria Estela Stenico
• Linha de fomento: Auxílio à Pesquisa - Apoio a Jovens Pesquisadores
• Processo FAPESP: 10/09867-9 - Bioprospecção de cianobactéria: seleção de cianopeptídeos para aplicação farmacêutica e biotecnológica
• Beneficiário: Maria Estela Stenico
• Linha de fomento: Bolsas no Brasil - Apoio a Jovens Pesquisadores