Toxins 2012, 4(6), 390-404; doi:10.3390/toxins4060390
Article

Effects of Cyanobacterial Lipopolysaccharides from Microcystis on Glutathione-Based Detoxification Pathways in the Zebrafish (Danio rerio) Embryo

1email, 2email, 3email, 4email and 1,* email
Received: 2 February 2012; in revised form: 14 May 2012 / Accepted: 14 May 2012 / Published: 25 May 2012
(This article belongs to the Special Issue Algal Toxins)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: Cyanobacteria (“blue-green algae”) are recognized producers of a diverse array of toxic secondary metabolites. Of these, the lipopolysaccharides (LPS), produced by all cyanobacteria, remain to be well investigated. In the current study, we specifically employed the zebrafish (Danio rerio) embryo to investigate the effects of LPS from geographically diverse strains of the widespread cyanobacterial genus, Microcystis, on several detoxifying enzymes/pathways, including glutathione-S-transferase (GST), glutathione peroxidase (GPx)/glutathione reductase (GR), superoxide dismutase (SOD), and catalase (CAT), and compared observed effects to those of heterotrophic bacterial (i.e., E. coli) LPS. In agreement with previous studies, cyanobacterial LPS significantly reduced GST in embryos exposed to LPS in all treatments. In contrast, GPx moderately increased in embryos exposed to LPS, with no effect on reciprocal GR activity. Interestingly, total glutathione levels were elevated in embryos exposed to Microcystis LPS, but the relative levels of reduced and oxidized glutathione (i.e., GSH/GSSG) were, likewise, elevated suggesting that oxidative stress is not involved in the observed effects as typical of heterotrophic bacterial LPS in mammalian systems. In further support of this, no effect was observed with respect to CAT or SOD activity. These findings demonstrate that Microcystis LPS affects glutathione-based detoxification pathways in the zebrafish embryo, and more generally, that this model is well suited for investigating the apparent toxicophore of cyanobacterial LPS, including possible differences in structure-activity relationships between heterotrophic and cyanobacterial LPS, and teleost fish versus mammalian systems.
Keywords: lipopolysaccharide; cyanobacteria; zebrafish; Microcystis; glutathione; detoxification pathways; oxidative stress
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MDPI and ACS Style

Jaja-Chimedza, A.; Gantar, M.; Mayer, G.D.; Gibbs, P.D.L.; Berry, J.P. Effects of Cyanobacterial Lipopolysaccharides from Microcystis on Glutathione-Based Detoxification Pathways in the Zebrafish (Danio rerio) Embryo. Toxins 2012, 4, 390-404.

AMA Style

Jaja-Chimedza A, Gantar M, Mayer GD, Gibbs PDL, Berry JP. Effects of Cyanobacterial Lipopolysaccharides from Microcystis on Glutathione-Based Detoxification Pathways in the Zebrafish (Danio rerio) Embryo. Toxins. 2012; 4(6):390-404.

Chicago/Turabian Style

Jaja-Chimedza, Asha; Gantar, Miroslav; Mayer, Gregory D.; Gibbs, Patrick D. L.; Berry, John P. 2012. "Effects of Cyanobacterial Lipopolysaccharides from Microcystis on Glutathione-Based Detoxification Pathways in the Zebrafish (Danio rerio) Embryo." Toxins 4, no. 6: 390-404.

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