Glyphosate Toxic to Mouth Cells & Damages DNA, Roundup Much Worse

Further evidence of genotoxic and cytotoxic effects – a prelude to cancer, birth defects and reproductive problems Dr Eva Sirinathsinghji

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New research finds that glyphosate causes cell and DNA damage to epithelial cells derived from the inside of the mouth and throat [1]. It raises concerns over the safety of inhaling glyphosate, one of the most common ways in which people are exposed to the herbicide.

Siegfried Knasmueller and his colleagues the Medical University of Vienna, Austria, found that Monsanto’s formulated version of glyphosate called Roundup Ultra Max caused cellular damage and DNA damage including chromosomal abnormalities and ultimately killed the cells at higher concentrations. Importantly, DNA damage occurred at concentrations below those required to induce cell damage, suggesting that the DNA damage was caused directly by glyphosate instead of being an indirect result of cell toxicity.

These are not the first findings of glyphosate-based herbicides’ cytotoxic and genotoxic effects. Numerous independent research teams have been documenting the hazards of glyphosate exposure over the last few years with in vivo, in vitro and clinical studies.

DNA damage was observed in blood samples from exposed residents in Argentina and Ecuador [2, 3]. Lab mice were found to harbour chromosomal and DNA damage in bone marrow, liver and kidney cells as well as lymphoid cells [4]. Similar effects were found in non-mammalian species, including sea urchins [5], goldfish [6, 7], eels [8], tilapia fish [9] as well as the fruitfly [10]. These experiments show that glyphosate herbicides are dangerous for humans and many other animals. Glyphosate is highly soluble in water, so impacts on aquatic wildlife may be of particular concern, especially following the recent report on the presence of glyphosate in rain water, groundwater, rivers and air [11, 12]. Its extreme toxic effects on amphibians such as frogs has already been shown (see [13] Roundup Kills Frogs, SiS 26). Cell damage has been documented in many cell types including those derived from the rat testis (see [14] Glyphosate Kills Rat Testes Cells, SiS 54), human placenta, umbilical cord, and embryo (see [15] Death by Multiple Poisoning, Glyphosate and Roundup, SiS 42), rat and carp neurones [16, 17], and liver [18, 19].

Multiple tests all show cellular damage in response to Roundup

To reflect occupational exposure, human buccal epithelial cells were exposed to glyphosate and Roundup for 20 minutes only at concentrations from 10 mg/L to 200 mg/L. The Roundup formulation used for the experiments contains 450 g/L of glyphosate and should be diluted according to the manufacturer’s instructions to 1–3 % before use (final concentration 4 500–13 500 mg/l). The researchers found some significant effects with 10-20 mg/l, equivalent to a 225–1 350-fold dilution of the spraying solution.

Cell damage was assessed by the release of the membrane-bound enzyme lactose dehydrogenase into the culture medium. The integrity and viability of cells was indicated by their staining with neutral red as only healthy cells retain the dye. Mitochondrial function was assessed by measuring the activity of the enzyme mitochondrial dehydrogenase with the substrate XXT that gives a yellow colour product. And cell proliferation was measured by the total protein content of the cell cultures.

The results showed that the cells were much more sensitive to the Roundup formulation than glyphosate. With Roundup, a significant effect was seen at a dose level of 40 mg/L with the XXT assay, while a clear increase of the lactose dehydrogenase levels was seen already with 10 mg/L. The cell proliferation and the neutral red assays were less responsive, with significant effects detected at 80 and 100 mg/L, respectively (still well below agricultural use levels). All effects were dose-dependent.

With glyphosate, no significant effects were seen in 3 of the 4 assays, with only lactose dehydrogenase showing significant effects at over 80 mg/l.

Multiple tests show Roundup causes DNA damage

DNA damage was analysed by two methods. The first is the Single Cell Gel Electrophoresis (SCGE) assay, which reveals single or double-stranded breaks in DNA. The second is a special comprehensive assay of chromosome instability that picks up many DNA aberrations including chromosome breakage, DNA misrepair, chromosome loss, as well as cell death by either necrosis (cell death that results from external stressors such as toxins), apoptosis (programmed cell-death) and cell growth. Different nuclear anomalies were measured including micronuclei, a biomarker of chromosomal damage, breakage or loss; nuclear buds, a biomarker of elimination of ampliﬁed DNA and/or DNA repair complexes; and nucleoplasmic bridges reflecting the formation of dicentric chromosomes (chromosomes with 2 instead of 1 centromere) , a marker of DNA misrepair and/or end-fusions of the chromosomes.

Significant effects on DNA integrity as assessed by the SCGE assay were seen at 20 mg/l of both Roundup and glyphosate, increasing in a dose-dependent manner.

Exposure of the cells for 20 minutes also led to a significant and dose-dependent increase of nuclear anomalies including increases in the total number of micronuclei beginning at 10 mg/L of Roundup, and 15 mg/L of glyphosate. The number of nuclear buds increased with exposure concentrations, starting at 10 mg/L with both glyphosate and Roundup. In the case of the nucleoplasmic bridges, the only significant effect was obtained with the highest dose of Roundup used (20 mg/L). Apoptotic cells were observed following 20mg/L of Roundup but not glyphosate, while necrosis occurred in response to 20mg/L of both Roundup and glyphosate.

In summary, Roundup was cytotoxic at concentrations as low as 20 mg/L, while its active ingredient was not generally cytotoxic to buccal epithelial cells. Both glyphosate and Roundup elicited genotoxic effects at concentrations below the level required to induce cell damage. The different effects between the active ingredient and its commercial formulation is consistent with previous work, including experiments done on testicular, placental, embryonic and umbilical cord cells (see above). These results may explain some of the ailments observed in people who work with this herbicide and adds yet more weight to an outright ban of the herbicide [20] Ban Glyphosate Herbicides Now, SiS 43).

Article first published 28/03/12

References

Koller VJ, Fürhacker M, Nersesyan A, Mišík M, Eisenbauer M, Knasmueller S. Cytotoxic and DNA-damaging properties of glyphosate and Roundup in human-derived buccal epithelial cells. Archives of Toxicology 2012 Feb 14. [Epub ahead of print] Sirinathsinghji E. Pesticide Illnesses and GM Soybeans. Ban on Aerial Spraying Demanded in Argentina, Science in Society 53, 2012 Paz-y-Miño C, Sánchez ME, Arévalo M, Muñoz MJ, Witte T, De-la- Carrera GO, Leone PE. Evaluation of DNA damage in an Ecuadorian population exposed to glyphosate. Genetics and Molecular Biology 2007, 30, 456-460. Bolognesi C, Bonatti C, Degan P, Gallerani E, Peluso M, Rabboni R, Roggieri P, Abbondandolo A. Genotoxic Activity of Glyphosate and Its Technical Formulation Roundup. Journal of Agricultural and Food Chemistry 1997, 45, 1957−1962. Marc J, Mulner-Lorillon O, Bellé R. Glyphosate-based pesticides affect cell cycle regulation. Biol Cell 2004, 96, 245-9. Bellé R, Le Bouffant R, Morales J, Cosson B, Cormier P, Mulner-Lorillon O. Sea urchin embryo, DNA-damaged cell cycle checkpoint and the mechanisms initiating cancer development. J Soc Biol 2007, 201, 317-27. Get copies of full article! 261. Cavas T, Konen S. 2007. Detection of cytogenetic and DNA damage in peripheral erythrocytes of goldfish (Carassius auratus) exposed to a glyphosate formulation using the micronucleus test and the comet assay. Mutagenesis 22, 263–268. Guilherme S, Gaivão I, Santos MA, Pacheco M. European eel (Anguilla anguilla) genotoxic and pro-oxidant responses following short-term exposure to Roundup--a glyphosate-based herbicide. Mutagenesis 2010, 25, 523-30. Jiraungkoorskul W, Upatham ES, Kruatrachue M, Sahaphong S, Vichasri-Grams S, Pokethitiyook P. Biochemical and histopathological effects of glyphosate herbicide on Nile tilapia (Oreochromis niloticus). Environmental Toxicology 2003, 18, 260-7. Kale PG, Petty BT Jr, Walker S, Ford JB, Dehkordi N, Tarasia S, Tasie BO, Kale R, Sohni YR. Mutagenicity testing of nine herbicides and pesticides currently used in agriculture. Environmental and Molecular Mutagenesis 1995, 25, 148-53. Technical Announcement: Widely Used Herbicide Commonly Found in Rain and Streams in the Mississippi River Basin, United States Geological Society, 8th October 2011 http://www.usgs.gov/newsroom/article.asp?ID=2909 Sanchís J, Kantiani L, Llorca M, Rubio F, Ginebreda A, Fraile J, Garrido T, Farré M. Determination of glyphosate in groundwater samples using an ultrasensitive immunoassay and confirmation by on-line solid-phase extraction followed by liquid chromatography coupled to tandem mass spectrometry. Analytical and Bioanalytical Chemistry 2012, 402, 2335-45. Sirinathsinghji E. Glyphosate Kills Rat Testes Cells. Science in Society 54, 2012, to appear. Ho MW. Roundup kills frogs.Science in Society 26. 13, 2005 Ho MW and Cherry B. Death by multiple poisoning, glyphosate and Roundup.Science in Society 42, 14, 2009 Astiz M, de Alaniz MJ, Marra CA. Antioxidant defense system in rats simultaneously intoxicated with agrochemicals. Environ Toxicol Pharmacol. 2009, 28, 465-73. Astiz M, de Alaniz MJ, Marra CA. Effect of pesticides on cell survival in liver and brain rat tissues. Ecotoxicol Environ Saf 2009, 72, 2025-32. Epub 2009 Jun 2. Szarek J, Siwicki A, Andrzejewska A, Terech-Majewska E, Banaszkiewicz T. Effects of the herbicide Roundup on the ultrastructural pattern of hepatocytes in carp (Cyprinus carpio) Mar. Environ. Res 2000, 50, 263–266 Malatesta M, Perdoni F, Santin F, Battistelli S, Muller S, Biggiogera F. Hepatoma tissue culture (HTC) cells as a model for investigating the effects of low concentrations of herbicide on cell structure and function. Toxicology In Vitro 2008, 22, 1853–60. Ho MW. Ban glyphosate herbicides now. Science in Society 43, 24-25, 2009.

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