Herbicide Roundup Research Articles

Lack of adverse effects in subchronic and chronic toxicity/carcinogenicity studies on the glyphosate-resistant genetically modified maize NK603 in Wistar Han RCC rats

In 2012, a controversial study on the long-term toxicity of a Roundup herbicide and the glyphosate-tolerant genetically modified (GM) maize NK603 was published. The EC-funded G-TwYST research consortium tested the potential subchronic and chronic toxicity as well as the carcinogenicity of the glyphosate-resistant genetically modified maize NK603 by performing two 90-day feeding trials, one with GM maize inclusion rates of 11 and 33% and one with inclusion rates of up to 50%, as well as a 2-year feeding trial with inclusion rates of 11 and 33% in male and female Wistar Han RCC rats by taking into account OECD Guidelines for the testing of chemicals and EFSA recommendations on the safety testing of whole-food/feed in laboratory animals. In all three trials, the NK603 maize, untreated and treated once with Roundup during its cultivation, and the conventional counterpart were tested. Differences between each test group and the control group were evaluated. Equivalence was assessed by comparing the observed difference to differences between non-GM reference groups in previous studies. In case of significant differences, whether the effects were dose-related and/or accompanied by changes in related parameters including histopathological findings was evaluated. It is concluded that no adverse effects related to the feeding of the NK603 maize cultivated with or without Roundup for up to 2 years were observed. Based on the outcome of the subchronic and combined chronic toxicity/carcinogenicity studies, recommendations on the scientific justification and added value of long-term feeding trials in the GM plant risk assessment process are presented.

On the Regulation of the Joint Use of Growth Stimulants and Pesticides in Forest Growing

The results of studying the effect of the growth stimulants Verva and Verva-El on the growth qualities of pine ordinary seedlings grown under the pre-sowing soil preparation using the roundup (glyphosate) herbicide are presented. The necessity of the presented experiments is connected with the establishment of the impact of the joint effect of new growth-promoting drugs and pesticides traditionally used in forestry on woody plants. It was shown that under laboratory conditions, the simultaneous presence of the roundup herbicide in the growth medium (agaragar) and seed treatment with the growth stimulants Verva and Verva-El leads to an inhibition of the growth of two-week-old pine seedlings, due to a decrease in the size of the roots. In the small-plot field experiment, an increase in the stem height was found in the variants using stimulants relative to this indicator in the variant where the pine was grown only with the use of roundup.

Метаболізм азотистих сполук у сироватці крові щурів трьох поколінь за згодовування гліфосат-резистентної генетично модифікованої сої та гербіциду «Roundup»

Метаболізм азотистих сполук у сироватці крові щурів трьох поколінь за згодовування гліфосат-резистентної генетично модифікованої сої та гербіциду «Roundup»

Changes in hemocytes of Biomphalaria glabrata infected with Echinostoma paraensei and exposed to glyphosate-based herbicide.

The immune system of snails is highly sensitive to pollutants, which can suppress its immune response. We investigated the effects of exposure to the glyphosate-based herbicide Roundup® Original on the snail Biomphalaria glabrata infected by the platyhelminth Echinostoma paraensei by evaluating changes in the snail's internal defense system. Four cohorts were studied: control group, infected snails, snails treated with Roundup®, and snails infected and treated with Roundup®. The hemocyte viability was assessed, morphological differentiation of cells was observed and flow cytometry was performed to determine the morphology, viability and the lectin expression profiles. The frequencies of dead hemocytes were lower in the infected group and higher in both pesticide treated groups. Three cell types were identified: blast-like cells, hyalinocytes and granulocytes. The highest number of all types of hemocytes, as well as the highest number of dead cells, were observed in the infected, pesticide-treated group. The association between infection and herbicide exposure greatly increased the frequency of dead hemocytes, suggesting that this condition impairs the internal defense system of B. glabrata making the snails more vulnerable to parasitic infections.

The acute and chronic effect of Roundup herbicide on histopathology and enzymatic antioxidant system of Oncorhynchus mykiss

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.

ВПЛИВ ПЕПТИДІВ НА СТАН ІМУННОЇ СИСТЕМИ ОРГАНІЗМУ ТА ВМІСТ БІЛКОВИХ ФРАКЦІЙ КРОВІ ЩУРІВ, УРАЖЕНИХ СОЛЯМИ ВАЖКИХ МЕТАЛІВ І РАУНДАПОМ

Вступ. Свинець, як і всі важкі метали, – протоплазматична отрута широкого спектра дії, що викликає зміни в нервовій, серцево-судинній системах та крові. Він порушує ферментативні реакції і знижує імунобіологічну резистентність організму. В організмі іони свинцю гальмують гуморальну імунну відповідь, що проявляється низьким продукуванням антитіл та імуноглобулінів класів M, E, A, збільшенням частоти респіраторних захворювань в осіб, уражених сполуками Плюмбуму.&#x0D; Мета дослідження – вивчити вплив пептиду цистеїл-гістидил-тирозил-гістидил-ізолейцину на стан імунної системи та вміст білкових фракцій у сироватці крові щурів різного віку з хронічним токсикозом, викликаним важкими металами і гліфосатом.&#x0D; Методи дослідження. Досліди проводили на лабораторних нелінійних білих щурах-самцях трьох вікових груп: статевого дозрівання, статевої зрілості й старих тваринах, яким внутрішньошлунково протягом 30 днів вводили водні розчини Плюмбум ацетату, Купрум сульфату, гліфосату (у формі гербіциду раундапу). З метою корекції на 21 день через 6 год після введення токсикантів протягом 10 днів вводили пептид цистеїл-гістидил-тирозил-гістидил-ізолейцин. Стан імунної системи оцінювали за рівнем імуноглобулінів класів A, M, G та циркулюючих імунних комплексів у сироватці крові щурів. &#x0D; Результати й обговорення. Встановлено, що в інтактних тварин і щурів при комбінованій дії Плюмбум ацетату, Купрум сульфату і гліфосату (у формі гербіциду раундапу) з віком підвищувалась концентрація циркулюючих імунних комплексів та імуноглобулінів у сироватці крові. Введення пептиду призводило до часткового відновлення співвідношення білкових фракцій у сироватці крові щурів та вмісту імуноглобулінів. &#x0D; Висновок. Використання пептиду як чинника корекції частково нормалізує стан імунної системи та співвідношення білкових фракцій у сироватці крові щурів із токсикозом, викликаним Плюмбум ацетатом, Купрум сульфатом і раундапом.

The interactive effects of predator stress, predation, and the herbicide Roundup

AbstractAs the number of studies examining the effects of contaminants grows, ecologists are becoming increasingly aware that contaminants can interact with natural stressors (e.g., competition and predator cues) in their effects on nontarget animals. In amphibians, predator cues can make contaminants more lethal under laboratory conditions, but the opposite outcome has been observed under more natural conditions with stratified water columns; stratification causes more pesticide to be present near the surface while predator cues scare spring‐breeding amphibians down to the benthos. I examined whether this phenomenon also occurs in three species of summer‐breeding amphibians (Hyla versicolor, Rana clamitans, and Rana catesbeiana) that were raised in outdoor mesocosms. Specifically, I asked how amphibian survival was affected by multiple concentrations of a common herbicide (glyphosate; commercial name: Roundup), the herbicide combined with chemical cues from predators (caged larval dragonflies; Anax junius), and the herbicide combined with lethal predators. Environmentally relevant concentrations of the herbicide caused high rates of tadpole mortality, but this outcome was substantially reversed by the addition of predator cues. With lethal predators, the tadpoles experienced such high mortality that the herbicide caused no additional effect. Roundup also induced morphological changes in Hyla versicolor, and the induced traits were different from those induced by predators. Collectively, these results suggest that while predator cues can make pesticides less lethal when thermal stratification occurs, highly lethal predators can overwhelm these effects. Thus, the impacts of such contaminants can be dramatically different in environments that do or do not contain high‐risk predators.

Effects of Ciprofloxacin and Roundup on seed germination and root development of maize

Their continuous release into the environment, associated with their inherent biological activity, has motivated investigations into the detrimental effects of antibiotics and herbicides in natural and agricultural ecosystems. In this study, the interactive effects of the antibiotic ciprofloxacin (Cipro) and the herbicide Roundup on seed germination and root development were investigated. Although both compounds act as inhibitors of the mitochondrial electron transport chain in seeds, neither Cipro nor Roundup disrupted germinability of maize seeds. However, Cipro accelerated germination by promoting ROS accumulation in seeds, while the stimulatory effect of Roundup on ROS-scavenging enzymes (catalase and ascorbate peroxidase) seems to prevent ROS-signaling, delaying the germination process. Roundup reduced root elongation, possibly due to its interference with auxin production, thereby preventing cell division, while Cipro stimulated root elongation by increasing root oxidative status. Cipro and Roundup showed antagonistic effects on maize seeds and root physiology. The presence of the antibiotic is likely not to disturb plant development; however, its stimulatory effects were not sufficient to overcome the deleterious effects of Roundup. According to our results, glyphosate-based herbicides must be carefully used during maize cropping and although antibiotics such as Cipro may not negatively impact agricultural production, their accumulation by crops must be investigated since this can be a pathway of antibiotic-insertion into the food chain.

Changes in hypopharyngeal glands of nurse bees (Apis mellifera) induced by pollen-containing sublethal doses of the herbicide Roundup®

Decreasing pollinator populations worldwide has generated great concern and stimulated countless studies to understand the origin of colony losses. One main cause is the indiscriminate use of different pesticides, producing subtle negative effects on bee physiology and behavior. Royal jelly synthesized in the hypopharyngeal glands is an essential protein for feeding all individuals of the hive, especially the queen. Therefore, the present study aimed to determine the effect of sublethal concentrations of Roundup® on the hypopharyngeal glands of nursing workers, including its interference with the production of royal jelly. The herbicide was found to promote changes in the cellular ultrastructure of these glands, causing early degeneration of the rough endoplasmic reticulum and morphological and structural changes in the mitochondria. No changes were noted in the amount of royal jelly produced, but additional long-term studies are necessary to determine possible qualitative changes. This is the first study to evaluate the effect of Roundup® on the royal jelly-producing glands, showing that resultant alterations in these structures can trigger damage to the development and survival of bee colonies.

Assessment of the oxidative and genotoxic effects of the glyphosate-based herbicide roundup on the freshwater shrimp, Macrobrachium nipponensis

In the present study, an acute toxic test was performed to assess the oxidative stress and genotoxic effects of the herbicide on the freshwater shrimp Macrobrachium nipponensis. The results showed that the 48-h and 96-h LC50 values of Roundup to M. nipponensis were 57.684 mg/L and 11.237 mg/L, respectively. For further investigation, the shrimps were exposed to sublethal concentrations of 0.35, 0.70, 1.40, 2.80 and 5.60 mg/L for 96 h. A significant decrease in total haemocytes count (THC) was observed at concentration of 5.60 mg/L throughout the experiment. The level of superoxide dismutase (SOD), catalase (CAT) and total antioxidant capacity (T-AOC) in all the treatments decreased in a dose- and time-dependent manner except for the concentration group of 0.35 mg/L. The malondialdehyde (MDA), hydrogen peroxide (H2O2) and protein carbonyl in serum increased significantly at concentrations of 2.80 mg/L and 5.60 mg/L. A significant decrease in acetylcholinesterase (AChE) activity was observed at each concentration (P＜0.05). In addition, the micronucleus (MN) frequency of haemocytes significantly increased (P＜0.05) at concentrations of 1.40, 2.80 and 5.60 mg/L, whereas the comet ratio and %DNA in the tails exhibited a clear time- and dose-dependent response during the exposure. The analysis of the integrated biomarker response (IBR) showed the induction of oxidative stress biomarkers and the inhibition of antioxidants, and this dose-dependent relation suggests the sensitivity and availability of all the biomarkers. These results revealed that Roundup had a prominent toxic effect on M. nipponensis based on the antioxidative response inhibition and genotoxicity.

Вплив цистеїл-гістидил-тирозил-гістидил-ізолейцину на вміст продуктів пероксидного окиснення ліпідів та активних форм Оксигену в щурів різного віку за дії важких металів і гліфосату

Introduction. Oxidative stress plays a critical role in the pathophysiology of several diseases: liver cirrhosis, atherosclerosis, diabetes mellitus, ischemic heart disease, carcinogenesis, etc. The main mechanism of oxidative stress induced is the disturbance oxidation and reduction processes by various factors such as toxic substances, radiation, temperature, drugs. Ions of heavy metals (transition metals) lead to the production of reactive oxygen species (ROS), causing a lipid peroxidation and other main biomolecules (proteins, nucleic acids).The aim of the study – to learn the influence of peptid: cisteil-histidil-tyrosil-histidil-isoleucine on generation of active forms of oxygen the content of products of free lipid peroxidation.Research Methods. The experiment was carried out on lab nonlinear white rats – males three age periods: puberty, mature and old aging animals. The rats received the lead acetate, copper sulfate, glyphosate (in herbicide Roundup) in combined and peptide as correction agent. Subhronic lesions in rats was modelled by intragastric administration of water solution of Lead Acetate at a dose of 11 mg/kg, Copper Sulfate at a dose of 13 mg / kg, Glyphosate at a dose of 250 mg / kg. Dehlorinated drinking tap water to intact animals was added. The correction effect was research by the during 10 days intragastric administration of water solution of peptide cisteil-histidil-tyrosil- histidil-isoleucine in a dose of 9 mg / kg at 21th day of the experiment after 6 hours after toxins. The degree of lipid peroxidation was assayed by estimating the thiobarbituric acid reactive substances (TBARS) and diene conjugates (DK) in blood serum and liver homogenates by spectrophotometric method. The superoxide anion-radical content was determined by test with Nitrobluetetrazolium, hydroxyl radical content was determined by the product of oxidation of 2-deoxyribose.Results and Discussion. It was established that the production of reactive oxygen species and lipid peroxidation increase by the combined effect of glyphosate (in Roundup form herbicide), lead acetate, copper sulfate in different age rats. There was a significant increase in concentration of TBARS, diene conjugates, superoxide anionradical and hydroxyl radical. One of the most probable mechanisms of peptide: cisteil-histidil-tyrosil-histidil-isoleucine corrective activity is based on its ability to antioxidantion activity that decrease concentration of a production of reactive oxygen species and a lipid peroxidation.Conclusion. The protective effect of peptide: tsysteil-histidil-tyrosil-histidil-isoleucine on liver damages rats induced by toxicity is administration induced loss to the production of reactive oxygen species, causing a lipid peroxidation

Roundup litigation discovery documents: implications for public health and journal ethics.

This paper reviews the court-released discovery documents obtained from litigation against Monsanto over its herbicide Roundup and through Freedom of Information Act requests (requests to regulatory agencies and public universities in the United States). We sought evidence of corporate malfeasance and undisclosed conflicts of interest with respect to issues of scientific integrity. The findings include evidence of ghostwriting, interference in journal publication, and undue influence of a federal regulatory agency.

Diquat Dibromide-induced cellular and developmental abnormalities in the pond snail Lymnaea palustris: Analysis of calcium dysregulation and cytoskeletal targets.

Diquat dibromide (DD), an active ingredient in the herbicide Roundup, is known to elicit oxidative stress in plant tissues leading to lipoperoxidation and apoptotic cell death. While exposure to DD has been demonstrated to cause ROS formation in animal tissues as well, its dose-dependent effects have been minimally characterized. Using embryos of the model organism Lymnaea palustris, we observe and quantify DD-induced effects including increased mortality, abnormal motility, heartrate arrhythmias, impaired shell formation in juvenile snails, and cellular dissociation using real-time imaging, heartrate assessment, and immunohistochemistry of cytoskeletal proteins. We have also demonstrated that calcium regulation is compromised in the presence of DD, causing a myriad of developmental and cytoskeletal defects, some of which are lessened by antioxidants. We suspect that the observed calcium dysregulation induced by high concentrations of DD (≥ 44.4 µg/L) may be one of the initial steps leading to the establishment of an intracellular positive feedback loop of ROS formation in the mitochondria and calcium release from the SER, leading to calcium efflux and apoptotic cell death. At low concentrations of DD (≤ 28 µg/L), however, apoptotic cell death does not occur, though cytoskeletal elements and calcium regulation are clearly impaired, suggesting that ROS formation may not occur at low DD concentrations and that the observed phenotypes result from ion dysregulation and disruption of cytoskeletal elements which negatively affect motility and heartrate. Ongoing research is being conducted to delineate the effects of DD on embryonic cytoskeletal elements.

Effects of Roundup Herbicide and Increase in Water Temperature on the Parameters of Peripheral Blood Cells in Amur Sleeper Perccottus glenii Dybowski

The separate and combined effects of chronic 30-day exposure to the herbicide Roundup in a sublethal concentration of 2 μg/L and an increase in water temperature at a rate of 8°C/h on the parameters of red and white blood in juveniles of Amur sleeper Perccottus glenii Dybowski have been studied. The ratio of mature and immature erythrocytes in the peripheral blood do not change under the influence of the studied factors. An increase in temperature after chronic exposure to Roundup leads to a decrease in red blood cell sizes and increase in the share of abnormal cells. Exposure to the herbicide and the rise in water temperature have the opposite effect on the number of amitosis in erythrocytes and the ratio of leucocyte cells; an antagonistic effect is identified under the combined action of the factors. Changes in white blood correspond to a nonspecific stress response; changes in red blood indicate a reduction in compensatory responses to hypoxia.

Evaluating the impact of synthetic herbicides on soil dwelling macrobes and the physical state of soil in an agro-ecosystem

This study evaluated three herbicides active ingredients: Paraquat, Glyphosate and 2,4-D Amine in commercial formulations as Frankoquat, Roundup and Agriherb respectively under field conditions to determine their influence on soil dwelling macrobes and the physical state of soil. Herbicides were serially diluted to three treatment concentrations for each plus three controls. Herbicide concentrations were applied to the demarcated field on three consecutive occasions in splits. Macrobes extraction from soil was done under a stereo microscope at 20 × magnification. The Simpson's diversity index was used to calculate the soil macrobes diversity. Soil water content, bulk density and total porosity of sampled soils were determined. The study revealed that both herbicides and non-herbicides treatment had no statistical significance (p > 0.05) on the soil dwelling macrobes. Also, a Simpson's index of diversity, estimated as 53.46%, showed how the experimental area is lowly diverse in the specific soil dwelling macrobes identified. Significant correlations existed between the soil water content, bulk density, total porosity and number of soil macrobes at p < 0.05. This level of significance showed in most instances for Frankoquat herbicide concentration treatments as well as Roundup. For Agriherb and control treatments the correlations were present but majority was not significant. In most situations, the soil dwelling macrobes decreased with increasing soil physical conditions. Thus, the dynamics in soil physical properties affected macrobes abundance in soil, with the slightest influence coming from the herbicides concentrations used in the experiment. The study recommended that Frankoquat and Roundup herbicides could be used to control weeds on farmer's field because, their influence were slightly felt on the soil macrobes and also, quite a number soil dwelling macrobes recovered after application.

California glyphosate warning requirement on hold

In a win for farm groups and pesticide companies, a federal judge has temporarily halted a cancer warning requirement for products sold in California that contain the herbicide glyphosate. For now, however, glyphosate will remain on the state’s list of chemicals known to cause cancer. California listed glyphosate as a known carcinogen on July 7, 2017, under its Proposition 65 law. That listing would have triggered a warning requirement effective July 7, 2018. Monsanto, which makes the glyphosate-based herbicide Roundup; farm groups; and others sued California in November, claiming that the Prop 65 listing and warning requirement would compel them “to make false, misleading, and highly controversial statements about their products.” The U.S. District Court for the Eastern District of California agreed that the required warnings would be “false and misleading.” In a Feb. 26 order, the court stated that “almost all other regulators have concluded that there is insufficient

Label-free optical biosensor for real-time monitoring the cytotoxicity of xenobiotics: A proof of principle study on glyphosate

Rapid and inexpensive biosensor technologies allowing real-time analysis of biomolecular and cellular events have become the basis of next-generation cell-based screening techniques. Our work opens up novel opportunities in the application of the high-throughput label-free Epic BenchTop optical biosensor in cell toxicity studies. The Epic technology records integrated cellular responses about changes in cell morphology and dynamic mass redistribution of cellular contents at the 100–150 nm layer above the sensor surface. The aim of the present study was to apply this novel technology to identify the effect of the herbicide Roundup Classic, its co-formulant polyethoxylated tallow amine (POEA), and its active ingredient glyphosate, on MC3T3-E1 cells adhered on the biosensor surface. The half maximal inhibitory concentrations of Roundup Classic, POEA and glyphosate upon 1 h of exposure were found to be 0.024%, 0.021% and 0.163% in serum-containing medium and 0.028%, 0.019% and 0.538% in serum-free conditions, respectively (at concentrations equivalent to the diluted Roundup solution). These results showed a good correlation with parallel end-point assays, demonstrating the outstanding utility of the Epic technique in cytotoxicity screening, allowing not only high-throughput, real-time detection, but also reduced assay run time and cytotoxicity assessment at end-points far before cell death would occur.

Degradation of Glyphosate by Mn-Oxide May Bypass Sarcosine and Form Glycine Directly after C-N Bond Cleavage.

Glyphosate is the active ingredient of the common herbicide Roundup. The increasing presence of glyphosate and its byproducts has raised concerns about its potential impact on the environment and human health. In this research, we investigated abiotic pathways of glyphosate degradation as catalyzed by birnessite under aerobic and neutral pH conditions to determine whether certain pathways have the potential to generate less harmful intermediate products. Nuclear magnetic resonance (NMR) spectroscopy and high-performance liquid chromatography (HPLC) were utilized to identify and quantify reaction products, and density functional theory (DFT) calculations were used to investigate the bond critical point (BCP) properties of the C-N bond in glyphosate and Mn(IV)-complexed glyphosate. We found that sarcosine, the commonly recognized precursor to glycine, was not present at detectable levels in any of our experiments despite the fact that its half-life (∼13.6 h) was greater than our sampling intervals. Abiotic degradation of glyphosate largely followed the glycine pathway rather than the AMPA (aminomethylphosphonic acid) pathway. Preferential cleavage of the phosphonate adjacent C-N bond to form glycine directly was also supported by our BCP analysis, which revealed that this C-N bond was disproportionately affected by the interaction of glyphosate with Mn(IV). Overall, these results provide useful insights into the potential pathways through which glyphosate may degrade via relatively benign intermediates.

Evaluation of Micronuclei Frequencies and Other Nuclear Alterations in Erythrocytes of Tilapia Rendalli (Perciformes:Cichlidae) Induced By Roundup® Herbicide

Micronuclei are chromosome fragments or entire chromosomes that do not incorporate in the main nucleus of the cell, remaining in the cytoplasm after mitosis. Micronucleus tests are usually used to inquire the damage caused in DNA by different external factors. Roundup→ is the most common herbicide used in the world, and it has an active agent denominated glyphosate that can be responsible for increases of nuclear alterations. The herbicide is a product of Monsanto®, so it does not affect Soya RR, but in natural conditions it could contaminate the aquatic ecosystems and its living creatures. The objective of this work was to inquire the frequency of erythrocytes with micronuclei and other nuclear alterations in the fish Tilapia rendalli induced by the herbicide Roundup® in different concentrations (5 mg/L and 15 mg/L) throughout 5 and 10 days of exposure. The blood cells were coloured with 15% Giemsa for 15 minutes and the counting was made in an optical microscope. In the present study, the frequency of erythrocytes with micronuclei induced by Roundup® in the treatments are larger than those in the control but are not significant (p>0.05). However, when the other nuclei alteration frequencies were compared with control they demonstrated significant (p<0.05) quantities in the concentrations of 5 and 15 mg/L along 5 and 10 days of exposure.

Disturbances in reproduction and expression of steroidogenic enzymes in aquatic invertebrates exposed to components of the herbicide Roundup

Exposure of organisms to environmental contaminants is a growing concern. We have investigated the effects of the individual active ingredients of the herbicide Roundup (glyphosate and diquat dibromide [DD]) since Roundup causes alterations in reproduction, mortality, and development in the aquatic snail Lymnaea palustris. Snails chronically treated with elevated but ecologically relevant levels of DD exhibit reduction in fecundity ( p &lt; 0.05), while fecundity in glyphosate-treated snails is comparable to or exceeds control levels. To investigate a possible mechanism for the reproductive disturbance, we monitored levels of steroid acute regulatory (StAR) protein in whole snails and observed a correlation in StAR protein decrease with treatment with Roundup, glyphosate, or DD. We detect StAR in organs where steroid biosynthesis occurs (ovotestis, brain, kidney); StAR protein is reduced following chronic exposure to Roundup, glyphosate, or DD ( p &lt; 0.01). Estradiol and testosterone concentrations in hemolymph were measured by enzyme-linked immunosorbent assay following 3-week exposure of snails to 3.5 mg/L glyphosate or 140 µg/L DD. Testosterone levels decrease in DD-treated groups ( p &lt; 0.05); a trend of lower testosterone is also observed in glyphosate-treated groups ( p &gt; 0.05). Estradiol concentration is greater than or equal to control levels in glyphosate, but decreased in DD ( p &lt; 0.05). Because of its role in the conversion of testosterone to estradiol, we monitored abundance of aromatase and observed a reduction ( p &lt; 0.05) in DD-treated snails (consistent with the drop in fecundity and estradiol levels) and a comparable level to control in glyphosate-treated snails (consistent with their high fecundity and estradiol levels). Although the toxicity of commercially-available Roundup to aquatic animals may have many contributing factors including its inactive surfactant, the constituent of Roundup associated with the greatest reproductive disturbances and observed developmental abnormalities of offspring is DD. This study details the analysis of particular herbicide constituents and their effect on specific targets in the reproductive pathway.