Nielsen et al., 2018
Nielsen, L. N., Roager, H. M., Casas, M. E., Frandsen, H. L., Gosewinkel, U., Bester, K., Licht, T. R., Hendriksen, N. B., & Bahl, M. I.; “Glyphosate has limited short-term effects on commensal bacterial community composition in the gut environment due to sufficient aromatic amino acid levels;” Environmental Pollution, 2018, 233, 364-376; DOI: 10.1016/j.envpol.2017.10.016.
ABSTRACT:
Recently, concerns have been raised that residues of glyphosate-based herbicides may interfere with the homeostasis of the intestinal bacterial community and thereby affect the health of humans or animals. The biochemical pathway for aromatic amino acid synthesis (Shikimate pathway), which is specifically inhibited by glyphosate, is shared by plants and numerous bacterial species. Several in vitro studies have shown that various groups of intestinal bacteria may be differently affected by glyphosate. Here, we present results from an animal exposure trial combining deep 16S rRNA gene sequencing of the bacterial community with liquid chromatography mass spectrometry (LC-MS) based metabolic profiling of aromatic amino acids and their downstream metabolites. We found that glyphosate as well as the commercial formulation Glyfonova((R))450 PLUS administered at up to fifty times the established European Acceptable Daily Intake (ADI = 0.5 mg/kg body weight) had very limited effects on bacterial community composition in Sprague Dawley rats during a two-week exposure trial. The effect of glyphosate on prototrophic bacterial growth was highly dependent on the availability of aromatic amino acids, suggesting that the observed limited effect on bacterial composition was due to the presence of sufficient amounts of aromatic amino acids in the intestinal environment. A strong correlation was observed between intestinal concentrations of glyphosate and intestinal pH, which may partly be explained by an observed reduction in acetic acid produced by the gut bacteria. We conclude that sufficient intestinal levels of aromatic amino acids provided by the diet alleviates the need for bacterial synthesis of aromatic amino acids and thus prevents an antimicrobial effect of glyphosate in vivo. It is however possible that the situation is different in cases of human malnutrition or in production animals. FULL TEXT
Larsen et al., 2012
Larsen, K., Najle, R., Lifschitz, A., & Virkel, G.; “Effects of sub-lethal exposure of rats to the herbicide glyphosate in drinking water: glutathione transferase enzyme activities, levels of reduced glutathione and lipid peroxidation in liver, kidneys and small intestine;” Environmental Toxicology and Pharmacology, 2012, 34(3), 811-818; DOI: 10.1016/j.etap.2012.09.005.
ABSTRACT:
Glyphosate (GLP), the active ingredient of many weed killing formulations, is a broad spectrum herbicide compound. Wistar rats were exposed during 30 or 90 days to the highest level (0.7 mg/L) of GLP allowed in water for human consumption (US EPA, 2011) and a 10-fold higher concentration (7 mg/L). The low levels of exposure to the herbicide did not produce histomorphological changes. The production of TBARS was similar or tended to be lower compared to control animals not exposed to the herbicide. In rats exposed to GLP, increased levels of reduced glutathione (GSH) and enhanced glutathione peroxidase (GPx) activity may act as a protective mechanism against possible detrimental effects of the herbicide. Overall, this work showed certain biochemical modifications, even at 3-20-fold lower doses of GLP than the oral reference dose of 2mg/kg/day (US EPA, 1993). The toxicological significance of these findings remains to be clarified. FULL TEXT
Chlopecka et al., 2017
Chlopecka, M., Mendel, M., Dziekan, N., & Karlik, W.; “The effect of glyphosate-based herbicide Roundup and its co-formulant, POEA, on the motoric activity of rat intestine – In vitro study;” Environmental Toxicology and Pharmacology, 2017, 49, 156-162; DOI: 10.1016/j.etap.2016.12.010.
ABSTRACT:
The study was aimed at evaluating the effect of Roundup, polyoxyethylene tallow amine (POEA) and mixture of glyphosate and POEA in different levels on the motoric activity of jejunum strips. The incubation in the Roundup solutions caused a significant, mostly miorelaxant, reversible reaction of smooth muscle; only in the highest tested dose which is equivalent to the agricultural concentration (1% corresponding to 1.7g glyphosate/L) there was an irreversible disturbance of the spontaneous contractility and reactivity. The incubation in POEA solutions in the range of low doses (0.256; 1.28; 6.4mg/L) resulted in a biphasic muscle reaction (relaxation and contraction); whereas in the range of high doses, i.e. 32; 160 and 800mg/L (agricultural spray concentrations) induced only a miorelaxant, irreversible response. The results indicate very high toxicity of POEA which exceeds the toxicity of the commercial formulations. Besides, it is postulated that glyphosate and POEA may display antagonistic interaction towards the motoric activity of gastrointestinal tract. FULL TEXT
Beuret et al., 2005
Beuret, Cecilia Judith, Zirulnik, Fanny, & Giménez, María Sofía; “Effect of the herbicide glyphosate on liver lipoperoxidation in pregnant rats and their fetuses;” Reproductive Toxicology, 2005, 19(4), 501-504; DOI: 10.1016/j.reprotox.2004.09.009.
ABSTRACT:
Glyphosate is a post-emergence herbicide that acts on the synthesis of amino acids and other endogenous metabolites in plants. It is commonly used in agriculture, forestry, and nurseries for the control or destruction of herbaceous plants. Metabolic processes during development and pregnancy could be sensitive to changes induced by glyphosate such as lipid peroxidation. The present study has investigated the effects that 1% glyphosate oral exposure has on lipoperoxidation and antioxidant enzyme systems in the maternal serum and liver of pregnant rats and their term fetuses at 21 days of gestation. The results suggest that excessive lipid peroxidation induced with glyphosate ingestion leads to an overload of maternal and fetal antioxidant defense systems.
El-Shenawy, 2009
El-Shenawy, Nahla S.; “Oxidative stress responses of rats exposed to Roundup and its active ingredient glyphosate;” Environmental Toxicology and Pharmacology, 2009, 28(3), 379-385; DOI: 10.1016/j.etap.2009.06.001.
Glyphosate is the active ingredient and polyoxyethyleneamine, the major component, is the surfactant present in the herbicide Roundup formulation. The objective of this study was to analyze potential cytotoxicity of the Roundup and its fundamental substance (glyphosate). Albino male rats were intraperitoneally treated with sub-lethal concentration of Roundup (269.9mg/kg) or glyphosate (134.95mg/kg) each 2 days, during 2 weeks. Hepatotoxicity was monitored by quantitative analysis of the serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) activities, total protein, albumin, triglyceride and cholesterol. Creatinine and urea were used as the biochemical markers of kidney damages. The second aim of this study to investigate how glyphosate alone or included in herbicide Roundup affected hepatic reduced glutathione (GSH) and lipid peroxidation (LPO) levels of animals as an index of antioxidant status and oxidative stress, respectively, as well as the serum nitric oxide (NO) and alpha tumour necrosis factor (TNF-α) were measured. Treatment of animals with Roundup induced the leakage of hepatic intracellular enzymes, ALT, AST and ALP suggesting irreversible damage in hepatocytes starting from the first week. It was found that the effects were different on the enzymes in Roundup and glyphosate-treated groups. Significant time-dependent depletion of GSH levels and induction of oxidative stress in liver by the elevated levels of LPO, further confirmed the potential of Roundup to induce oxidative stress in hepatic tissue. However, glyphosate caused significant increases in NO levels more than Roundup after 2 weeks of treatment. Both treatments increased the level of TNF-α by the same manner. The results suggest that excessive antioxidant disruptor and oxidative stress is induced with Roundup than glyphosate.
Ford et al., 2017
Ford, B., Bateman, L. A., Gutierrez-Palominos, L., Park, R., & Nomura, D. K.; “Mapping Proteome-wide Targets of Glyphosate in Mice;” Cell Chemical Biology, 2017, 24(2), 133-140; DOI: 10.1016/j.chembiol.2016.12.013.
ABSTRACT:
Glyphosate, the active ingredient in the herbicide Roundup, is one of the most widely used pesticides in agriculture and home garden use. Whether glyphosate causes any mammalian toxicity remains highly controversial. While many studies have associated glyphosate with numerous adverse health effects, the mechanisms underlying glyphosate toxicity in mammals remain poorly understood. Here, we used activity-based protein profiling to map glyphosate targets in mice. We show that glyphosate at high doses can be metabolized in vivo to reactive metabolites such as glyoxylate and react with cysteines across many proteins in mouse liver. We show that glyoxylate inhibits liver fatty acid oxidation enzymes and glyphosate treatment in mice increases the levels of triglycerides and cholesteryl esters, likely resulting from diversion of fatty acids away from oxidation and toward other lipid pathways. Our study highlights the utility of using chemoproteomics to identify novel toxicological mechanisms of environmental chemicals such as glyphosate. FULL TEXT
Gallegos et al., 2016
Gallegos, Cristina E., Bartos, Mariana, Bras, Cristina, Gumilar, Fernanda, Antonelli, Marta C., & Minetti, Alejandra; “Exposure to a glyphosate-based herbicide during pregnancy and lactation induces neurobehavioral alterations in rat offspring;” NeuroToxicology, 2016, 53, 20-28; DOI: 10.1016/j.neuro.2015.11.015.
ABSTRACT:
The impact of sub-lethal doses of herbicides on human health and the environment is a matter of controversy. Due to the fact that evidence particularly of the effects of glyphosate on the central nervous system of rat offspring by in utero exposure is scarce, the purpose of the present study was to assess the neurobehavioral effects of chronic exposure to a glyphosate-containing herbicide during pregnancy and lactation. To this end, pregnant Wistar rats were exposed through drinking water to 0.2% or 0.4% of a commercial formulation of glyphosate (corresponding to a concentration of 0.65 or 1.30g/L of glyphosate, respectively) during pregnancy and lactation and neurobehavioral alterations in offspring were analyzed. The postnatal day on which each pup acquired neonatal reflexes (righting, cliff aversion and negative geotaxis) and that on which eyes and auditory canals were fully opened were recorded for the assessment of sensorimotor development. Locomotor activity and anxiety levels were monitored via open field test and plus maze test, respectively, in 45- and 90-day-old offspring. Pups exposed to a glyphosate-based herbicide showed early onset of cliff aversion reflex and early auditory canal opening. A decrease in locomotor activity and in anxiety levels was also observed in the groups exposed to a glyphosate-containing herbicide. Findings from the present study reveal that early exposure to a glyphosate-based herbicide affects the central nervous system in rat offspring probably by altering mechanisms or neurotransmitter systems that regulate locomotor activity and anxiety.
Hued, 2012
Hued, Andrea Cecilia, Oberhofer, Sabrina, & de los Ángeles Bistoni, María; “Exposure to a Commercial Glyphosate Formulation (Roundup®) Alters Normal Gill and Liver Histology and Affects Male Sexual Activity of Jenynsia multidentata (Anablepidae, Cyprinodontiformes);” Archives of Environmental Contamination and Toxicology, 2012, 62(1), 107-117; DOI: 10.1007/s00244-011-9686-7.
ABSTRACT:
Roundup is the most popular commercial glyphosate formulation applied in the cultivation of genetically modified glyphosate-resistant crops. The aim of this study was to evaluate the histological lesions of the neotropical native fish, Jenynsia multidentata, in response to acute and subchronic exposure to Roundup and to determine if subchronic exposure to the herbicide causes changes in male sexual activity of individuals exposed to a sublethal concentration (0.5 mg/l) for 7 and 28 days. The estimated 96-h LC50 was 19.02 mg/l for both male and female fish. Gill and liver histological lesions were evaluated through histopathological indices allowing quantification of the histological damages in fish exposed to different concentrations of the herbicide. Roundup induced different histological alterations in a concentration-dependent manner. In subchronic-exposure tests, Roundup also altered normal histology of the studied organs and caused a significant decrease in the number of copulations and mating success in male fish exposed to the herbicide. It is expected that in natural environments contaminated with Roundup, both general health condition and reproductive success of J. multidenatata could be seriously affected.
Meshkini et al., 2018
Meshkini, S., Rahimi-Arnaei, M., & Tafi, A. A.; “The acute and chronic effect of Roundup herbicide on histopathology and enzymatic antioxidant system of Oncorhynchus mykiss;” International Journal of Environmental Science and Technology, 2018; DOI: 10.1007/s13762-018-2095-y.
ABSTRACT:
Unconventional and uncontrolled use of agricultural pesticides and their influence in aquatic ecosystems during drainage process causes the accumulation of these toxins in body tissues of fish, and finally, it endangers human health. In order to determine the amount of pollution of Roundup pesticide in aquatics, acute and chronic effects of this poison on gill, kidney, and liver tissues and biochemical activities of cerebral acetyl cholinesterase and liver catalase in rainbow trout (Oncorhynchus mykiss) were investigated. To determine LC50 of Roundup pesticide in rainbow trout, acute doses of Roundup were introduced to fish tanks and fish mortality was recorded for 96 h, and Roundup LC50 was determined using SPSS Probit test. Chronic doses were determined based on the obtained LC50, and the effects of these concentrations were assessed on gill, kidney and liver tissues and cerebral acetyl cholinesterase and liver catalase activities over 28 days. Based on histopathology results, the following changes were observed: adhesion of secondary lamellae, bending of secondary lamellae in gill tissue, glomerular wrinkling, dilatation of Bowman’s capsule space in kidney tissue and necrosis, cellular swelling, and lipid degeneration in liver tissue. Cerebral acetyl cholinesterase and liver catalase activities significantly reduced in groups exposed to Roundup herbicide compared to the control group (p < 0.05). Generally, chronic concentrations of Roundup herbicide cause undesirable tissue and enzymatic changes in antioxidant system of rainbow trout. Therefore, assessment of biochemical factors and histopathological studies can be used as biomarkers in tracing the effects of agricultural toxins on aquatic habitat.
Ren et al., 2019
Ren, X., Dai, P., Perveen, A., Tang, Q., Zhao, L., Jia, X., Li, Y., & Li, C.; “Effects of chronic glyphosate exposure to pregnant mice on hepatic lipid metabolism in offspring;” Environmental Pollution, 2019, 254(Pt A), 112906; DOI: 10.1016/j.envpol.2019.07.074.
ABSTRACT:
Glyphosate is the active ingredient in Roundup, one of the most popular herbicides in the world, and its toxicity has caused increasing concerns. The present study aims to investigate the toxic effects of prenatal exposure to pure glyphosate or Roundup on lipid metabolism in offspring. During gestational days (GDs), ICR mice (from Institute of Cancer Research) were given distilled water, 0.5% glyphosate solution (w/v, 0.5 g/100 ml) or 0.5%-glyphosate Roundup solution orally. The livers and serum samples of the offspring were collected on gestational day 19 (GD19), postnatal day 7 (PND7) and PND21. The results showed a significant decrease in the body weight and obvious hepatic steatosis with excessive lipid droplet formation in offspring. Moreover, the concentrations of lipids such as triglycerides (TGs), total cholesterol (T-CHO), and low-density lipoprotein cholesterols (LDL-C) increased to a significant extent in both the serum and livers. Furthermore, there were significant differences in the expression levels of the genes SREBP1C, SREBP2, Fasn, Hmgcr, Hmgcs and PPARa, which are related to lipid biosynthesis or catabolism in the liver. These results demonstrate that chronic prenatal exposure to glyphosate can result in lipid metabolism disruption in the offspring of mice, as glyphosate exerts a negative influence on the expression of lipogenesis genes. FULL TEXT