Induction of micronuclei and nuclear abnormalities in tadpoles of the common toad (Rhinella arenarum) treated with the herbicides Liberty registered and glufosinate-ammonium

• Published in: Mutation research. Genetic toxicology and environmental mutagenesis 2014-07, Vol.769, p.7-12
• Main Authors: Lajmanovich, Rafael C, Cabagna-Zenklusen, Mariana C, Attademo, Andres M, Junges, Celina M, Peltzer, Paola M, Basso, Agustin, Lorenzatti, Eduardo
• Format: Article
• Language: English
• Subjects: Amphibia
• ISSN: 1383-5718
• DOI: 10.1016/j.mrgentox.2014.04.009

The assessment of micronucleated erythrocytes (ME) in blood represents a widely used method for the detection of chromosomal damage by chemical agents, such as herbicides that may occur as water contaminants. We investigated the changes in some circulating blood-cell parameters of tadpoles of the common toad (Rhinella arenarum) that were exposed during 48 or 96h to three sub-lethal concentrations (3.75, 7.5, and 15mg/L) of a commercial formulation of a glufosinate-ammonium (GLA)-based herbicide (Liberty registered , LY registered ) as well as to the corresponding active ingredient GLA. The frequency of ME and other erythrocyte nuclear abnormalities (ENA, i.e., lobed nuclei, binucleates or segmented nuclei, kidney-shaped nuclei, notched nuclei, and picnotic nuclei) were evaluated and compared with positive (cyclophosphamide, CP, 40mg/L) and negative (de-chlorinated tap water) controls. The results indicate that the exposure of R. arenarum tadpoles to LY registered induces a concentration-dependent increase in ME frequency. The ENA frequency at 48h was also significantly higher than that in the negative control group for all the chemicals assayed (CP, LY registered and GLA) whereas at 96h, increases in ENA over the negative control group were found only for CP and GLA (7.5mg/L). Our study demonstrates that the commercial formulation of a GLA-based herbicide induces micronucleus formation in R. arenarum tadpoles, in contrast to the active ingredient. According to these results, the inert ingredients of the commercial formulation played an important role in the production of genotoxic damage in erythrocytes of amphibian tadpoles.