In vitro genomic damage caused by glyphosate and its metabolite AMPA.

Glyphosate is the most widely used systemic herbicide. There is ample scientific literature on the effects of this compound and its metabolite aminomethylphosphonic acid (AMPA), whereas their possible combined genotoxic action has not yet been studied. With the present study, we aimed to determine the level of genomic damage caused by glyphosate and AMPA in cultured human lymphocytes and to investigate the possible genotoxic action when both compounds were present at the same concentrations in the cultures. We used a micronuclei assay to test the genotoxicity of glyphosate and AMPA at six concentrations (0.0125, 0.025, 0.050, 0.100, 0.250, 0.500 µg/mL), which are more realistic than the highest concentrations used in previous published studies. Our data showed an increase in micronuclei frequency after treatment with both glyphosate and AMPA starting from 0.050 µg/mL up to 0.500 µg/mL. Similarly, a genomic damage was observed also in the cultures treated with the same concentrations of both compounds, except for exposure to 0.0065 and 0.0125 µg/mL. No synergistic action was observed. Finally, a significant increase in apoptotic cells was observed in cultures treated with the highest concentration of tested xenobiotics, while a significant increase in necrotic cells was observed also at the concentration of 0.250 µg/mL of both glyphosate and AMPA alone and in combination (0.125 + 0.125 µg/mL). Results of our study indicate that both glyphosate and its metabolite AMPA are able to cause genomic damage in human lymphocyte cultures, both alone and when present in equal concentrations.

Cellular and Genomic Instability Induced by the Herbicide Glufosinate-Ammonium: An In Vitro and In Vivo Approach.

Glufosinate-ammonium (GLA), an organophosphate herbicide, is released at high concentrations in the environment, leading to concerns over its potential genotoxic effects. However, few articles are available in the literature reporting the possible cellular and nuclear effects of this compound. We assessed, by in vitro and in vivo micronucleus assays, the genotoxicity of GLA on cultured human lymphocytes and Lymnaea stagnalis hemocytes at six concentrations: 0.010 (the established acceptable daily intake value), 0.020, 0.050, 0.100, 0.200, and 0.500 µg/mL. In human lymphocytes, our results reveal a significant and concentration-dependent increase in micronuclei frequency at concentrations from 0.100 to 0.500 µg/mL, while in L. stagnalis hemocytes, significant differences were found at 0.200 and 0.500 µg/mL. A significant reduction in the proliferation index was observed at all tested concentrations, with the only exception of 0.010 µg/mL, indicating that the exposure to GLA could lead to increased cytotoxic effects. In L. stagnalis, a significant reduction in laid eggs and body growth was also observed at all concentrations. In conclusion, we provided evidence of the genomic and cellular damage induced by GLA on both cultured human lymphocytes and a model organism's hemocytes; in addition, we also demonstrated its effects on cell proliferation and reproductive health in L. stagnalis.

Genotoxicological and physiological effects of glyphosate and its metabolite, aminomethylphosphonic acid, on the freshwater invertebrate Lymnaea stagnalis.

Aminomethylphosphonic acid (AMPA) is the main metabolite in the degradation of glyphosate, a broad-spectrum herbicide, and it is more toxic and persistent in the environment than the glyphosate itself. Owing to their extensive use, both chemicals pose a serious risk to aquatic ecosystems. Here, we explored the genotoxicological and physiological effects of glyphosate, AMPA, and the mixed solution in the proportion 1:1 in Lymnaea stagnalis, a freshwater gastropod snail. To do this, adult individuals were exposed to increasing nominal concentrations (0.0125, 0.025, 0.050, 0.100, 0.250, 0.500 µg/mL) in all three treatments once a week for four weeks. The genotoxicological effects were estimated as genomic damage, as defined by the number of micronuclei and nuclear buds observed in hemocytes, while the physiological effects were estimated as the effects on somatic growth and egg production. Exposure to glyphosate, AMPA, and the mixed solution caused genomic damage, as measured in increased frequency of micronuclei and nuclear buds and in adverse effects on somatic growth and egg production. Our findings suggest the need for more research into the harmful and synergistic effects of glyphosate and AMPA and of pesticides and their metabolites in general.