DNA damage in fish (Anguilla anguilla) exposed to a glyphosate-based herbicide – Elucidation of organ-specificity and the role of oxidative stress

Guilherme, Sofia; Gaivão, Isabel; Santos, M.A.; Pacheco, Mário

doi:10.1016/j.mrgentox.2011.10.017

Cited by 113 publications

(61 citation statements)

References 49 publications

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“…The European eel (A. anguilla) was adopted as test species due to its sensitivity and suitability as bioindicator. As demonstrated in previous studies (Guilherme et al 2010(Guilherme et al , 2012, this species showed to be able of reflecting the pernicious effects of pesticides, namely Roundup Ò .…”

Section: Introductionsupporting

confidence: 71%

Differential genotoxicity of Roundup® formulation and its constituents in blood cells of fish (Anguilla anguilla): considerations on chemical interactions and DNA damaging mechanisms

et al. 2012

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It has been widely recognized that pesticides represent a potential threat in aquatic ecosystems. However, the knowledge on the genotoxicity of pesticides to fish is still limited. Moreover, genotoxic studies have been almost exclusively focused on the active ingredients, whereas the effect of adjuvants is frequently ignored. Hence, the present study addressed the herbicide Roundup®, evaluating the relative contribution of the active ingredient (glyphosate) and the surfactant (polyethoxylated amine; POEA) to the genotoxicity of the commercial formulation on Anguilla anguilla. Fish were exposed to equivalent concentrations of Roundup® (58, 116 μg L⁻¹), glyphosate (17.9, 35.7 μg L⁻¹) and POEA (9.3, 18.6 μg L⁻¹), during 1 and 3 days. The comet assay was applied to blood cells, either as the standard procedure, or with an extra step involving DNA lesion-specific repair enzymes in an attempt to clarify DNA damaging mechanisms. The results confirmed the genotoxicity of Roundup®, also demonstrating the genotoxic potential of glyphosate and POEA individually. Though both components contributed to the overall genotoxicity of the pesticide formulation, the sum of their individual effects was never observed, pointing out an antagonistic interaction. Although POEA is far from being considered biologically inert, it did not increase the risk associated to glyphosate when the two were combined. The analysis of oxidatively induced breaks suggested that oxidation of DNA bases was not a dominant mechanism of damage. The present findings highlighted the risk posed to fish populations by the assessed chemicals, jointly or individually, emphasizing the need to define regulatory thresholds for all the formulation components and recommending, in particular, the revision of the hazard classification of POEA.

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Section: Introductionsupporting

confidence: 71%

Differential genotoxicity of Roundup® formulation and its constituents in blood cells of fish (Anguilla anguilla): considerations on chemical interactions and DNA damaging mechanisms

et al. 2012

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“…As, SOD plays an important role in the defense against the toxic effects of ROS, which can clean up O 2 -to protect cells from lesions and maintain the balance between oxidant and antioxidant ( Li et al, 2003). The results disagreed with Guilherme et al (2012) and Xing et al (2012). The decrease in the hepatic SOD level may be probably due to dismutase O 2 -˙ and to decompose H 2 O 2.…”

Section: Resultsmentioning

confidence: 93%

Vitamin E as antioxidant in female african catfish (Clarias gariepinus) exposed to chronic toxicity of atrazine

Kadry

Amer

Marzouk

et al. 2012

Egypt. J. of Aquatic Biolo. and Fish.

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The present study was planned aiming to investigate the effects of atrazine herbicide exposure on stress biomarkers acetylcholinesterase activity (AchE) and cortisol, oxidative stress responses and the histopathological changes in liver of female Clarias gariepinus and the ameliorative effect of vitamin E supplementation (240mg/kg diet) on the degree of atrazine sublethal toxicity (1.37mg/l) for 6 weeks. Chronic exposure to atrazine revealed a marked inhibition in the activity of AchE. But, significant increase of serum cortisol level was recorded. Moreover, atrazine exposure was associated with a marked induction of oxidative damage in liver tissue as evidenced by increased level of lipid peroxidation (LPO) and reduced glutathione (GSH) content. Atrazine exposure also led to a significant increase in the activities of catalase (CAT) and superoxide dismutase (SOD).Furthermore, histopathological examination of the liver of exposed fish showed dilatation and congestion of blood vessels, fatty degeneration, necrosis and pyknotic nuclei of hepatocytes. However, fish fed diet supplemented with vitamin E exhibited protective effect by minimizing the atrazine-induced toxicity, through measured values more or less similar to the control group fish.

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“…A second publication reported positive Comet results in erythrocytes of the goldfish, Carassius auratus, exposed to up to 15 ppm glyphosate concentration of a RoundupÔ-branded GBF for 2, 4 or 6 d (Cavas & Konen, 2007). Positive comet results were also reported in erythrocytes and liver and gill cells of the European eel, Anguilla anguilla, exposed to 0.058 and 0.116 mg/mL of a RoundupÔ-branded GBF in water for 1 or 3 d (Guilherme et al, 2010;Guilherme et al, 2012). Positive comet effects were also observed in liver and blood cells isolated from the fish species Corydoras paleatus exposed to 0.067 mg/mL of RoundupÔ-branded GBF for 3, 6 or 9 days (de Castilhos Ghisi & Cestari, 2012).…”

Section: Glyphosate-based Formulationsmentioning

confidence: 98%

Review of genotoxicity studies of glyphosate and glyphosate-based formulations

Kier

Kirkland²

2013

Critical Reviews in Toxicology

120

102

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An earlier review of the toxicity of glyphosate and the original Roundupä-branded formulation concluded that neither glyphosate nor the formulation poses a risk for the production of heritable/somatic mutations in humans. The present review of subsequent genotoxicity publications and regulatory studies of glyphosate and glyphosate-based formulations (GBFs) incorporates all of the findings into a weight of evidence for genotoxicity. An overwhelming preponderance of negative results in well-conducted bacterial reversion and in vivo mammalian micronucleus and chromosomal aberration assays indicates that glyphosate and typical GBFs are not genotoxic in these core assays. Negative results for in vitro gene mutation and a majority of negative results for chromosomal effect assays in mammalian cells add to the weight of evidence that glyphosate is not typically genotoxic for these endpoints in mammalian systems. Mixed results were observed for micronucleus assays of GBFs in nonmammalian systems. Reports of positive results for DNA damage endpoints indicate that glyphosate and GBFs tend to elicit DNA damage effects at high or toxic dose levels, but the data suggest that this is due to cytotoxicity rather than DNA interaction with GBF activity perhaps associated with the surfactants present in many GBFs. Glyphosate and typical GBFs do not appear to present significant genotoxic risk under normal conditions of human or environmental exposures.

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DNA damage in fish (Anguilla anguilla) exposed to a glyphosate-based herbicide – Elucidation of organ-specificity and the role of oxidative stress

Cited by 113 publications

References 49 publications

Differential genotoxicity of Roundup® formulation and its constituents in blood cells of fish (Anguilla anguilla): considerations on chemical interactions and DNA damaging mechanisms

Differential genotoxicity of Roundup® formulation and its constituents in blood cells of fish (Anguilla anguilla): considerations on chemical interactions and DNA damaging mechanisms

Vitamin E as antioxidant in female african catfish (Clarias gariepinus) exposed to chronic toxicity of atrazine

Review of genotoxicity studies of glyphosate and glyphosate-based formulations

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