Glyphosate - HH-RA.org

Bibliography Tag: glyphosate

Shehata et al., 2013

Shehata, A. A., Schrodl, W., Aldin, A. A., Hafez, H. M., & Kruger, M.; “The effect of glyphosate on potential pathogens and beneficial members of poultry microbiota in vitro;” Current Microbiology, 2013, 66(4), 350-358; DOI: 10.1007/s00284-012-0277-2.

ABSTRACT:

The use of glyphosate modifies the environment which stresses the living microorganisms. The aim of the present study was to determine the real impact of glyphosate on potential pathogens and beneficial members of poultry microbiota in vitro. The presented results evidence that the highly pathogenic bacteria as Salmonella Entritidis, Salmonella Gallinarum, Salmonella Typhimurium, Clostridium perfringens and Clostridium botulinum are highly resistant to glyphosate. However, most of beneficial bacteria as Enterococcus faecalis, Enterococcus faecium, Bacillus badius, Bifidobacterium adolescentis and Lactobacillus spp. were found to be moderate to highly susceptible. Also Campylobacter spp. were found to be susceptible to glyphosate. A reduction of beneficial bacteria in the gastrointestinal tract microbiota by ingestion of glyphosate could disturb the normal gut bacterial community. Also, the toxicity of glyphosate to the most prevalent Enterococcus spp. could be a significant predisposing factor that is associated with the increase in C. botulinum-mediated diseases by suppressing the antagonistic effect of these bacteria on clostridia. FULL TEXT

Patterson et al., 2018

Patterson, E. L., Pettinga, D. J., Ravet, K., Neve, P., & Gaines, T. A.; “Glyphosate Resistance and EPSPS Gene Duplication: Convergent Evolution in Multiple Plant Species;” Journal of Heredity, 2018, 109(2), 117-125; DOI: 10.1093/jhered/esx087.

ABSTRACT:

One of the increasingly widespread mechanisms of resistance to the herbicide glyphosate is copy number variation (CNV) of the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene. EPSPS gene duplication has been reported in 8 weed species, ranging from 3 to 5 extra copies to more than 150 extra copies. In the case of Palmer amaranth (Amaranthus palmeri), a section of >300 kb containing EPSPS and many other genes has been replicated and inserted at new loci throughout the genome, resulting in significant increase in total genome size. The replicated sequence contains several classes of mobile genetic elements including helitrons, raising the intriguing possibility of extra-chromosomal replication of the EPSPS-containing sequence. In kochia (Kochia scoparia), from 3 to more than 10 extra EPSPS copies are arranged as a tandem gene duplication at one locus. In the remaining 6 weed species that exhibit EPSPS gene duplication, little is known about the underlying mechanisms of gene duplication or their entire sequence. There is mounting evidence that adaptive gene amplification is an important mode of evolution in the face of intense human-mediated selection pressure. The convergent evolution of CNVs for glyphosate resistance in weeds, through at least 2 different mechanisms, may be indicative of a more general importance for this mechanism of adaptation in plants. CNVs warrant further investigation across plant functional genomics for adaptation to biotic and abiotic stresses, particularly for adaptive evolution on rapid time scales. FULL TEXT

de Melo et al., 2019

de Melo, M. S., Nazari, E. M., Joaquim-Justo, C., Muller, Y. M. R., & Gismondi, E.; “Effects of low glyphosate-based herbicide concentrations on endocrine-related gene expression in the decapoda Macrobrachium potiuna;” Environmental Science and Pollution Research International, 2019, 26(21), 21535-21545; DOI: 10.1007/s11356-019-05496-1.

ABSTRACT:

Glyphosate-based herbicides (GBH) are the most used herbicides worldwide and are considered as endocrine-disrupting compounds (EDC) for non-target organisms. However, effects of GBH on their endocrine systems remain poorly understood. Thus, the aim of this study was to assess the effects of low concentrations of Roundup WG(R) on growth and reproduction process molecules in both males and females of the decapod crustacean Macrobrachium potiuna, by the relative transcript expression levels of the ecdysteroid receptor (EcR), the molt-inhibiting hormone (MIH), and the vitellogenin (Vg) genes. Prawns were exposed to three concentrations of GBH (0.0065, 0.065, and 0.28 mg L(-1)) for 7 and 14 days. The results revealed that only in males the three genes transcript levels were influenced by the GBH concentration, time of exposure, and the interaction between the concentrations and time of exposure, suggesting that males were more sensitive to GBH than females. For males, after 7 days of exposure at 0.065 mg L(-1), EcR and MIH were over-expressed, while the Vg expression was only over-expressed after 14 days. The present study highlighted that GBH impacted endocrine systems of M. potiuna. Moreover, EcR and MIH gene expressions could be promising EDC biomarkers of exposure in crustaceans. These results also indicate that GBH concentrations, considered secure by regulatory agencies, should be reviewed to minimize the effects on non-target organisms. FULL TEXT

Duforestel et al., 2019

Duforestel, Manon, Nadaradjane, Arulraj, Bougras-Cartron, Gwenola, Briand, Joséphine, Olivier, Christophe, Frenel, Jean-Sébastien, Vallette, François M., Lelièvre, Sophie A., & Cartron, Pierre-François; “Glyphosate Primes Mammary Cells for Tumorigenesis by Reprogramming the Epigenome in a TET3-Dependent Manner;” Frontiers in Genetics, 2019, 10; DOI: 10.3389/fgene.2019.00885.

ABSTRACT:

The acknowledgment that pollutants might influence the epigenome raises serious concerns regarding their long-term impact on the development of chronic diseases. The herbicide glyphosate has been scrutinized for an impact on cancer incidence, but reports demonstrate the difficulty of linking estimates of exposure and response analysis. An approach to better apprehend a potential risk impact for cancer is to follow a synergistic approach, as cancer rarely occurs in response to one risk factor. The known influence of glyphosate on estrogen-regulated pathway makes it a logical target of investigation in breast cancer research. We have used nonneoplastic MCF10A cells in a repeated glyphosate exposure pattern over 21 days. Glyphosate triggered a significant reduction in DNA methylation, as shown by the level of 5-methylcytosine DNA; however, in contrast to strong demethylating agent and cancer promoter UP peptide, glyphosate-treated cells did not lead to tumor development. Whereas UP acts through a DNMT1/PCNA/UHRF1 pathway, glyphosate triggered increased activity of ten-eleven translocation (TET)3. Combining glyphosate with enhanced expression of microRNA (miR) 182-5p associated with breast cancer induced tumor development in 50% of mice. Culture of primary cells from resected tumors revealed a luminal B (ER+/PR-/HER2-) phenotype in response to glyphosate-miR182-5p exposure with sensitivity to tamoxifen and invasive and migratory potentials. Tumor development could be prevented either by specifically inhibiting miR 182-5p or by treating glyphosate-miR 182-5p-cells with dimethyloxallyl glycine, an inhibitor of TET pathway. Looking for potential epigenetic marks of TET-mediated gene regulation under glyphosate exposure, we identified MTRNR2L2 and DUX4 genes, the hypomethylation of which was sustained even after stopping glyphosate exposure for 6 weeks. Our findings reveal that low pressure but sustained DNA hypomethylation occurring via the TET pathway primes cells for oncogenic response in the presence of another potential risk factor. These results warrant further investigation of glyphosate-mediated breast cancer risk. FULL TEXT

Pandey et al., 2019

Pandey, A., Dhabade, P., & Kumarasamy, A.; “Inflammatory Effects of Subacute Exposure of Roundup in Rat Liver and Adipose Tissue;” Dose Response, 2019, 17(2), 1559325819843380; DOI: 10.1177/1559325819843380.

ABSTRACT:

Roundup is a popular herbicide containing glyphosate as an active ingredient. The formulation of Roundup is speculated to have critical toxic effects, one among which is chronic inflammation. The present study analyzed adverse inflammatory effects in the liver and adipose tissue of rats after a subacute exposure of Roundup. Adult male rats were exposed to various doses of Roundup (0, 5, 10, 25, 50, 100 and 250 mg/kg bodyweight [bw] glyphosate) orally, everyday for 14 days. On day 15, liver and adipose tissues from dosed rats were analyzed for inflammation markers. C-reactive protein in liver, cytokines IL-1beta, TNF-alpha, IL-6, and inflammatory response marker, and prostaglandin-endoperoxide synthase were upregulated in liver and adipose of rats exposed to higher (100 and 250 mg/kg bw/d) doses of Roundup. Cumulatively, our data suggest development of inflammation in lipid and hepatic organs upon exposure to Roundup. Furthermore, liver histological studies showed formation of vacuoles, fibroid tissue, and glycogen depletion in the groups treated with doses of higher Roundup. These observations suggest progression of fatty liver disease in Roundup-treated adult rats. In summary, our data suggest progression of multiorgan inflammation, liver scarring, and dysfunction post short-term exposure of Roundup in adult male rats. FULL TEXT

Mills et al., 2019

Mills, P. J., Caussy, C., & Loomba, R.; “Glyphosate Excretion is Associated With Steatohepatitis and Advanced Liver Fibrosis in Patients With Fatty Liver Disease;” Clinical Gastroenterology and Hepatology, 2019; DOI: 10.1016/j.cgh.2019.03.045.

ABSTRACT:

Nonalcoholic fatty liver disease (NAFLD) is currently the most common chronic liver disease in developed countries.(1) Patients with nonalcoholic steatohepatitis (NASH) are considered to be at a higher risk of fibrosis progression and development to cirrhosis and hepatocellular carcinoma.

Among potential environmental contributors to the pathophysiology of NAFLD are exposure to pesticides and herbicides. Glyphosate, the primary weed-killing ingredient in Roundup (Monsanto, St Louis, MO), is sprayed on genetically modified crops and on many non–genetically modified grain crops and is found in these crops at harvest.

Rodents chronically fed with a low dosage of glyphosate exhibit signs of hepatotoxicity, liver congestion, necrosis, and DNA damage of the liver cells. This study examined excretion levels of glyphosate and its primary metabolite aminomethylphosphonic acid (AMPA) in a well-characterized and prospectively recruited cohort of patients with biopsy-proven NAFLD. FULL TEXT

Mesnage et al., 2019

Mesnage, R., Benbrook, C., & Antoniou, M. N.; “Insight into the confusion over surfactant co-formulants in glyphosate-based herbicides;” Food and Chemical Toxicology, 2019, 128, 137-145; DOI: 10.1016/j.fct.2019.03.053.

ABSTRACT:

Glyphosate is the active ingredient in glyphosate-based herbicides (GBHs). Other chemicals in GBHs are presumed as inert by regulatory authorities and are largely ignored in pesticide safety evaluations. We identified the surfactants in a cross-section of GBH formulations and compared their acute toxic effects. The first generation of polyethoxylated amine (POEA) surfactants (POE-tallowamine) in Roundup are markedly more toxic than glyphosate and heightened concerns of risks to human health, especially among heavily-exposed applicators. Beginning in the mid-1990s, first-generation POEAs were progressively replaced by other POEA surfactants, ethoxylated etheramines, which exhibited lower non-target toxic effects. Lingering concern over surfactant toxicity was mitigated at least in part within the European Union by the introduction of propoxylated quaternary ammonium surfactants. This class of POEA surfactants are approximately 100 times less toxic to aquatic ecosystems and human cells than previous GBH-POEA surfactants. As GBH composition is legally classified as confidential commercial information, confusion concerning the identity and concentrations of co-formulants is common and descriptions of test substances in published studies are often erroneous or incomplete. In order to resolve this confusion, laws requiring disclosure of the chemical composition of pesticide products could be enacted. Research to understand health implications from ingesting these substances is required. FULL TEXT

Pahwa et al., 2019

Pahwa, M., Beane Freeman, L. E., Spinelli, J. J., Blair, A., McLaughlin, J. R., Zahm, S. H., Cantor, K. P., Weisenburger, D. D., Punam Pahwa, P. P., Dosman, J. A., Demers, P. A., & Harris, S. A.; “Glyphosate use and associations with non-Hodgkin lymphoma major histological sub-types: findings from the North American Pooled Project;” Scandinavian Journal of Work, Environment, & Health, 2019; DOI: 10.5271/sjweh.3830.

ABSTRACT:

OBJECTIVES:

Some epidemiological studies have suggested positive associations between glyphosate use and non-Hodgkin lymphoma (NHL), but evidence is inconsistent and few studies could evaluate histological sub-types. Here, associations between glyphosate use and NHL incidence overall and by histological sub-type were evaluated in a pooled analysis of case-control studies.

METHODS:

The analysis included 1690 NHL cases [647 diffuse large B-cell lymphoma (DLBCL), 468 follicular lymphoma (FL), 171 small lymphocytic lymphoma (SLL), and 404 other sub-types] and 5131 controls. Logistic regression was used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI) for NHL overall and sub-types with self-reported ever/never, duration, frequency, and lifetime-days of glyphosate use.

RESULTS:

Subjects who ever used glyphosate had an excess of NHL overall (OR 1.43, 95% CI 1.11-1.83). After adjustment for other pesticides, the OR for NHL overall with “ever use” was 1.13 (95% CI 0.84-1.51), with a statistically significant association for handling glyphosate >2 days/year (OR 1.73, 95% CI 1.02-2.94, P-trend=0.2). In pesticide-adjusted sub-type analyses, the ordinal measure of lifetime-days was statistically significant (P=0.03) for SLL, and associations were elevated, but not statistically significant, for ever years or days/year of use. Handling glyphosate >2 days/year had an excess of DLBCL (OR 2.14, 95% CI 1.07-4.28; P-trend=0.2). However, as with the other sub-types, consistent patterns of association across different metrics were not observed.

CONCLUSIONS:

There was some limited evidence of an association between glyphosate use and NHL in this pooled analysis. Suggestive associations, especially for SLL, deserve additional attention. FULL TEXT

Gage et al., 2019

Gage, Karla L., Krausz, Ronald F., & Walters, S. Alan; “Emerging Challenges for Weed Management in Herbicide-Resistant Crops;” Agriculture, 2019, 9(8); DOI: 10.3390/agriculture9080180.

ABSTRACT:

Since weed management is such a critical component of agronomic crop production systems, herbicides are widely used to provide weed control to ensure that yields are maximized. In the last few years, herbicide-resistant (HR) crops, particularly those that are glyphosate-resistant, and more recently, those with dicamba (3,6-dichloro-2-methoxybenzoic acid) and 2,4-D (2,4-dichlorophenoxyacetic acid) resistance are changing the way many growers manage weeds. However, past reliance on glyphosate and mistakes made in stewardship of the glyphosate-resistant cropping systemhave directly led to the current weed resistance problems that now occur in many agronomic cropping systems, and new technologies must be well-stewarded. New herbicide-resistant trait technologies in soybean, such as dicamba-, 2,4-D-, and isoxaflutole- ((5-cyclopropyl-4-isoxazolyl)[2-(methylsulfonyl)-4-(trifluoromethyl)phenyl]methanone) resistance, are being combined with glyphosate- and glufosinate-resistance traits to manage herbicide-resistant weed populations. In cropping systems with glyphosate-resistant weed species, these new trait options may provide effective weed management tools, although there may be increased risk of off-target movement and susceptible plant damage with the use of some of these technologies. The use of diverse weed management practices to reduce the selection pressure for herbicide-resistant weed evolution is essential to preserve the utility of new traits. The use of herbicides with differing sites of action (SOAs), ideally in combination as mixtures, but also in rotation as part of a weed management program may slow the evolution of resistance in some cases. Increased selection pressure from the effects of some herbicide mixtures may lead to more cases of metabolic herbicide resistance. The most effective long-term approach for weed resistance management is the use of Integrated Weed Management (IWM) which may build the ecological complexity of the cropping system. Given the challenges in management of herbicide-resistant weeds, IWM will likely play a critical role in enhancing future food security for a growing global population. FULL TEXT

Kleter et al., 2011

Kleter, Gijs A, Unsworth, B, & Harris, Caroline A; “The impact of altered herbicide residues in transgenic herbicide-resistant crops on standard setting for herbicide residues;” Pest Management Science, 2011, 67, 1193-1210; DOI: 10.1002/ps.2128.

ABSTRACT:

The global area covered with transgenic (genetically modified) crops has rapidly increased since their introduction in the mid-1990s.Most of these crops have been rendered herbicide resistant, for which it can be envisaged that the modification has an impact on the profile and level of herbicide residues within these crops. In this article, the four main categories of herbicide resistance, including resistance to acetolactate-synthase inhibitors, bromoxynil, glufosinate and glyphosate, are reviewed. The topics considered are the molecular mechanism underlying the herbicide resistance, the nature and levels of the residues formed and their impact on the residue definition and maximum residue limits (MRLs) defined by the Codex Alimentarius Commission and national authorities. No general conclusions can be drawn concerning the nature and level of residues, which has to be done on a case-by-case basis. International residue definitions and MRLs are still lacking for some herbicide–crop combinations, and harmonisation is therefore recommended. FULL TEXT

Bibliography Index