Herbicide Roundup Research Articles

Glyphosate impairs both structure and function of GABAergic synapses in hippocampal neurons

Glyphosate (Gly) is a broad-spectrum herbicide responsible for the inhibition of the enzyme 5-enolpyruvylshikimate-3-phosphate synthase known to be expressed exclusively in plants and not in animals. For decades Gly has been thought to be ineffective in mammals, including humans, until it was demonstrated that rodents treated with the Gly-based herbicide Roundup showed reduced content of neurotransmitters (e.g., serotonin, dopamine, norepinephrine, and acetylcholine), increased oxidative stress in the brain associated with anxiety and depression-like behaviors and learning and memory deficits. Despite compelling evidence pointing to a neurotoxic effect of Gly, an in-depth functional description of its effects on synaptic transmission is still lacking. To investigate the synaptic alterations dependent on Gly administration we performed whole-cell patch-clamp recordings and immunocytochemistry on mouse primary cultured hippocampal neurons. Our findings reveal that 30 min incubation of Gly at the acceptable daily intake dose severely impaired inhibitory GABAergic synapses. Further analysis pointed out that Gly decreased the number of postsynaptic GABAA receptors and reduced the amplitude of evoked inhibitory postsynaptic currents, the readily releasable pool size available for synchronous release and the quantal size. Finally, a decreased number of release sites has been observed. Consistently, morphological analyses showed that the density of both pre- and post-synaptic inhibitory compartments decorating pyramidal cell dendrites was reduced by Gly. In conclusion, our experiments define for the first time the effects induced by Gly on GABAergic synapses, and reveal that Gly significantly impairs both pre- and postsynaptic mechanisms.

The ability of photochemical decomposition products of the Roundup to induce oxidative stress in bacterial cells

BACKGROUND: A common non-selective systemic herbicide Roundup (Glyphosate, active ingredient N-phosphonomethylglycine, N-PMG) is used to control perennial weeds. It is necessary to assess the hazard of the products of photochemical decomposition of N-FMG formed under the influence of solar UV and ozone. AIM: Using lux-biosensors based on Escherichia coli, studying the ability of N-FMG photochemical degradation products to induce oxidative stress in bacterial cells. MATERIALS AND METHODS: The work used the active substance of the herbicide Roundup N-phosphonomethylglycine (N-PMG), biosensors E. coli (pSoxS-lux), E. coli (pKatG-lux). UV radiation, Mass spectrometry. RESULTS: Using biosensors, it was shown that the products of photochemical decomposition of N-PMG (2-(N-hydroxymethyl-hydroxyamine) ethanoic acid) cause an increase in the concentration of superoxide anion radical and H2O2 in E. coli cells, which induces oxidative stress in the bacterial cell. CONCLUSIONS: The photochemical decomposition product of N-PMG (2-(N-hydroxymethyl-hydroxyamine) ethanoic acid) induces the formation of superoxide anion radical and H2O2 in bacterial cells.

Behavioral and Biochemical Effects of Glyphosate-Based Herbicide Roundup on Unionid Mussels: Are Mussels Good Indicators of Water Pollution with Glyphosate-Based Pesticides?

The behavioral (filtration activity) and biochemical (oxidative stress) effects of Roundup 360 Plus (active substance glyphosate) herbicide on two species of unionid mussels, Unio tumidus (Philipsson, 1788) and Anodonta anatina (L.), were evaluated at concentrations ranging from 15 to 1500 μg L−1 of glyphosate for five days. During all experiments, we did not record the mortality of the studied mussel species. Exposure to Roundup herbicide induced dose-dependent filtration disruptions in both U. tumidus and A. anatina. Exposure of the mussels to a low and environmentally relevant concentration 15 µg glyphosate L−1 resulted in a slight (<20%) and temporary decrease in mean valve dilation. Exposure of the mussels to Roundup at relatively high concentrations caused drastic and prolonged shell closure and a reduction in the mussel shell opening rate. Exposure of both mussel species to herbicide resulted in oxidative stress; an increase in superoxide dismutase enzymatic activity was detected. The most significant increase in SOD activity was observed after the exposure to the highest Roundup concentration. However, no correlation between the Roundup concentration and enzymatic activity was found. The use of unionid mussels to detect environmentally relevant concentrations of Roundup, as a part of biological early warning system for pollution, is limited, but they can serve to detect the incidental pollution of aquatic ecosystems with high concentrations of this herbicide.

Effects of the glyphosate-based herbicide roundup on C. elegans and S. cerevisiae mortality, reproduction, and transcription fidelity

Glyphosate-based weed killers such as Roundup have been implicated in detrimental effects on single- and multicellular eukaryotic model organism health and longevity. However, the mode(s) of action for these effects are currently unknown. In this study, we investigate the impact of exposure to Roundup on two model organisms: Saccharomyces cerevisiae and Caenorhabditis elegans and test the hypothesis that exposure to Roundup decreases transcription fidelity. Population growth assays and motility assays were performed in order to determine the phenotypic effects of Roundup exposure. We also used Rolling-Circle Amplification RNA sequencing to quantify the impact of exposure to Roundup on transcription fidelity in these two model organisms. Our results show that exposure to the glyphosate-based herbicide Roundup increases mortality, reduces reproduction, and increases transcription error rates in C. elegans and S. cerevisiae. We suggest that these effects may be due in part to the involvement of inflammation and oxidative stress, conditions which may also contribute to increases in transcription error rates.

Impact of pesticides on marine coral reef foraminifera

Our laboratory study looked into how pesticides affect the foraminifera species Heterostegina depressa and their obligatory algal endosymbionts. We incubated the foraminifera separately with different types of pesticides at varying concentrations (1 %, 0.01 % and 0.0001 %); we included the insecticide Confidor© (active substance: imidacloprid), the fungicide Pronto©Plus (tebuconazole), and the herbicide Roundup© (glyphosate). Our evaluation focused on the symbiont's photosynthetically active area (PA), and the uptake of dissolved inorganic carbon (DIC) and nitrogen (nitrate) to determine the vitality of the foraminifera. Our findings showed that even the lowest doses of the fungicide and herbicide caused irreparable damage to the foraminifera and their symbionts. While the insecticide only deactivated the symbionts (PA = 0) at the highest concentration (1 %), the fungicide, and herbicide caused complete deactivation even at the lowest levels provided (0.0001 %). The fungicide had the strongest toxic effect on the foraminiferal host regarding reduced isotope uptake. In conclusion, all pesticides had a negative impact on the holosymbiont, with the host showing varying degrees of sensitivity towards different types of pesticides.

Effect of glyphosate-based herbicide roundup on hemato-biochemistry of Labeo rohita (Hamilton, 1822) and susceptibility to Aeromonas hydrophila infection.

In the present study, comprehensive research was executed to investigate the salient toxic effects of glyphosate herbicide in static water system by evaluating the haemato-biochemical profiles of Labio rohita. A challenge study against Aeromonas hydrophila was conducted to determine disease susceptibility of the fish, treated to varying concentrations of commercial-grade glyphosate herbicide. A static range finding bioassay and definitive test revealed that the 96-h LC50 value of glyphosate was 10.16mg L-1. The experimental fish were subjected to three sub-lethal concentrations of 2.06, 1.03, and 0.63mgl-1 for 28days and changes were documented bi-fortnightly to study haemato-biochemical alterationsin the fish. Significantly (p < 0.05) low values in red blood corpuscles (RBC), hemoglobin (Hb), and hematocrit value (Hct) were documented. In contrast, a significant (p < 0.05) escalation in white blood corpuscles (WBC) was documented in comparison to the control. Biochemical and stress markers such as blood glucose, total protein, and alkaline phosphatase (ALP) were significantly (p < 0.05) low, whereas serum glutamate pyruvate transaminase (SGPT) and serum glutamate oxaloacetate transaminase (SGOT) escalated significantly (p < 0.05). Chronic exposure to glyphosate, on the other hand, had the least effect on the Na+ and K+ ions. Further, a challenge assay against A. hydrophila at three sub-lethal glyphosate concentrations demonstrated a synergistic impact that reduced the fish survivability. The findings conclude that persistent low glyphosate concentrations in aquatic ecosystems show significant pathophysiological changes in L. rohita, with increased vulnerability to infections. Altogether, our findings indicate the need to further study the possibleassessment for a sustainable bio-remediation technique, mitigation of the detrimental effects of glyphosate exposure in fish, and recommendation of an acceptable residue concentration of the glyphosate in aquatic ecosystem.

Roundup® disrupts tissue architecture, attenuates Na+/K+-ATPase expression, and induces protein oxidation/nitration, cellular apoptosis, and antioxidant enzyme expressions in the gills of goldfish, Carassius auratus

Extensive agricultural activities to feed the growing population are one major driving force behind aquatic pollution. Different types of pesticides are used in farmlands to increase crop production and wash up into water bodies. Glyphosate-based herbicide Roundup® is one of the most used pesticides in the United States; however, its effects on teleost species are still poorly understood. This study focused on the effects of environmentally relevant concentrations of Roundup exposure (low- and high-dose: 0.5 and 5 μg/L for 2-week) on Na+/K+-ATPase (NKA, a biomarker for sodium‑potassium ion pump efficacy), cytochrome P450-1A (CYP1A, a monooxygenase enzyme), 2,4-dinitrophenyl protein (DNP, a biomarker for protein oxidation), 3-nitrotyrosine protein (NTP, a biomarker for protein nitration), superoxidase dismutase (SOD, an antioxidant enzyme), catalase (CAT, an antioxidant enzyme) expressions, and cellular apoptosis in the gills of goldfish. Histopathological and in situ TUNEL analyses showed widespread tissue damage, including lamellar fusion, loss of gill architecture, club shape of primary lamellae, mucous formation, and distortion in the epithelium layer, as well as apoptotic nuclei in gills. Immunohistochemical and qRT-PCR analyses provided insights into the expressions of molecular indicators in gills. Fish exposed to Roundup exhibited a significant (P < 0.05) downregulation of NKA expression in gills. Additionally, we observed upregulation of CYP1A, DNP, NTP, SOD, and CAT expressions in the gills of goldfish. Overall, our results suggest that exposure to Roundup causes disruption of gill architecture, induces protein oxidation/nitration and cellular apoptosis, and alters prooxidant-antioxidant homeostasis in tissues, which may lead to reduced fitness and survivability of teleost species.

Herbicides Roundup (Glyphosate) and Paraquat (Gramoxone) as chemical ripeners for sugarcane variety SP70-1143 (A case study at Debel Khozaie Agro-Industrial Co.)

In the Khuzestan province of Iran, sugarcane harvesting is normally carried out between the early November and March periods, when rain and frost risks occur. This results in delayed harvesting and reduced profitability due to cane deterioration and a reduction in cane sucrose content. Management strategies such as the application of chemical ripeners were hypothesized to tackle such challenges by harvesting the crop earlier when the natural ripening condition was poor. Consequently, paraquat and roundup herbicides were applied as chemical ripeners to investigate the effect of their application time and rate on accelerating the ripening quality of the sugar cane variety SP70-1143 using a split-plot design. The treatments were control (unsprayed) [T0]; 1.0 Lha&lt;sup&gt;−1&lt;/sup&gt; Paraquat (250 ppm) applied 8 weeks before harvesting (8WBH) [T1]; 0.8 Lha&lt;sup&gt;−1&lt;/sup&gt; Roundup (200 ppm) applied 8WBH [T2]; 1.0 Lha&lt;sup&gt;−1&lt;/sup&gt; Paraquat (250 ppm) applied 5 weeks before harvesting (5WBH) [T3], and 0.8 Lha&lt;sup&gt;−1&lt;/sup&gt; Roundup (200 ppm) applied 5WBH [T4]. The results indicated that the glyphosate application treatments T2 and T4 induced a significant improvement in the sugarcane juice quality through an increase in Brix%, Pol%, %purity, and commercial cane sugar (CCS%) starting 1 week after their application. The results also confirmed the feasibility of an earlier harvesting operation on November 1st, one month before normal harvesting time in the study area, without significant loss of sucrose by application of 0.8 Lha&lt;sup&gt;−1&lt;/sup&gt; Glyphosate (roundup), 8WBH.

Lower Concentrations of the Glyphosate-Based Herbicide Roundup® Cause Developmental Defects in Artemia salina.

Roundup® is the most used glyphosate-based herbicide. During agricultural use it may directly contaminate existing aquatic ecosystems, posing severe concerns for the safety of nontarget terrestrial and aquatic organisms. We investigated the outcome of exposure to different concentrations of glyphosate in Roundup on cyst hatchability, toxicity, and teratogenic effects in the aquatic crustacean Artemia salina that inhabits diverse types of salt waters and, as a filter feeder, carries a greater risk of being exposed to pollutants. We found that exposure to 144 and 288 μg/ml glyphosate in Roundup resulted in cysts unable to complete diapause, and hatchability was completely inhibited during all exposure times tested (17-48 h). A glyphosate concentration of 288 μg/ml in Roundup was lethal to A. salina nauplii, and the lower concentrations (9, 18, 36, 72 μg/ml) had no significant effects on viability. In addition, sublethal and environmentally safe concentrations of glyphosate (0.72 μg/ml) in Roundup affected the early development of A. salina nauplii, with significantly decreased body lengths and reduced widths of the tail, abdomen, and head. The increased level of catalase activity observed in nauplii exposed to 0.72 μg/ml glyphosate for 24 h and those exposed to 7.2 and 72 μg/ml glyphosate for 48 h may be linked to excessive reactive oxygen species levels that had been induced by Roundup. In conclusion, Roundup containing >72 μg/ml glyphosate totally inhibited hatching of cysts and exerted toxic effects on A. salina nauplii. The increased prevalence of developmental defects in the nauplii observed at 0.72 μg/ml glyphosate signifies possible teratogenicity of Roundup exposure even at environmentally relevant concentrations of glyphosate, possibly due to disturbance of the antioxidant defenses, which needs further investigation. Environ Toxicol Chem 2023;00:1-9. © 2023 SETAC.

Toxicology, histophysiological and nutritional changes in Apis mellifera (Hymenoptera: Apidae) submitted to limonene and natural pesticides in comparison to synthetic pesticides

Apis mellifera has ecological, economic and social importance. Thus, this study aimed to compare, at a toxicological, physiological and nutritional level, the insecticidal activity of natural pesticides in comparison with synthetic ones, adding knowledge about the impacts of these products and verifying their safety for these animals. Toxicity bioassays were performed to obtain the LC50 (lethal concentration) of the products (Azamax®, Limonene, Karate® and Roundup®) through Probit analysis. The concentrations and toxicity ratios (TR) obtained, in decreasing toxicity level, were Karate® (0.0134 mL/100 mL, 53,156 times) > Limonene (1.44 mL/100 mL, 494.64 times) > Roundup® (712 .29 mL/100 mL). It was not possible to obtain the LC50 for Azamax®, as concentrations above 250 mL/100 mL caused repellency and below there was no mortality. LC50 and Azamax® concentrations were used as a treatment in histological, histochemical and biochemical analyses. Although the herbicide Roundup® has shown low toxicity by ingestion, it and the Limonene were the substances that most interfered with nutritional biochemical parameters, in addition to causing histopathological changes in midgut cells. The insecticide Karate® also led to histopathological changes in cells and a reduction in important macromolecules used in biochemical functions. Despite the repellency observed in the insecticide Azamax®, A. mellifera presented morphological alterations in the digestive cells and in the absorption of nutrients. It is concluded that natural pesticides can be as harmful to A. mellifera bees as synthetic ones, and they can cause deleterious effects on the digestive physiology of these insects, which may reflect on their reproduction.

Analysis of Prussian carp (Carassius gibelio B.) oocytes under the influence of Roundup® herbicide.

The aim of this study was to investigate the effect of Roundup® herbicide on the maturation of Prussian carp oocytes under laboratory conditions. The Prussian carp is currently one of the most common fish species in Polish freshwater ichthyofauna. For the investigation, oocytes from five sexually mature female Prussian carp were used, segmented into three groups, and incubated for 24 h in Cortland's saline, treated with varied concentrations of the herbicide Roundup® (0 ng - control, R1 - 10 ng/ml, and R2 - 100 ng/ml). Subsequent to this period, assays were performed using the prepared plates to determine the level of 17α,20β-dihydroxyprogesterone (17α,20β-P) utilizing the standard ELISA technique. In determining the 17α,20β-P via ELISA, the medium was extracted from each tested oocyte group. Oocyte maturity was assessed through preservation in serra fluid, and, to categorize the maturity stage of the oocytes utilizing a four-point scale - contingent upon the nucleus's position - the formerly preserved oocytes were dehydrated and subsequently analyzed. A contrast was noted in the percentage of oocytes at varied stages between the control group and the experimental groups. Specifically, a higher concentration of Roundup® (100 ng/ml) accelerated to expedite the initial migration of the nucleus in oocytes. In conclusion, the obtained results show the adverse effect of Roundup® on hormonal regulation and maturation in Prussian carp oocytes.

Adverse impacts of Roundup on soil bacteria, soil chemistry and mycorrhizal fungi during restoration of a Colorado grassland

Glyphosate is a widely used herbicide in agricultural, domestic, and restoration settings to manage weeds and invasive plants and is the active ingredient in the herbicide formulation Roundup. Concurrently with its drastic increase in usage, concern over indirect ecosystem effects and effects on non-target species has grown. In restoration, glyphosate is often used to remove invasive plants so native plants may be re-introduced. However, successful reintroductions require soils and microbial communities that support native plant growth, and it is critical that glyphosate applications do not harm soil microbes such as mycorrhizal fungi. Despite previous studies investigating the effects of glyphosate on soils and microbial communities, comprehensive field experiments combining soil chemistry and next generation sequencing technologies to describe both bacterial and eukaryotic responses to glyphosate are limited, especially in the contexts of ecosystem restoration and soil health. We studied the effects of the glyphosate-based herbicide Roundup Promax at frequencies of 0, 2, 4, and 5 applications over the course of 12 months on soil biotic and abiotic soil health indicators in a Colorado prairie dominated by the invasive cool-season grass Bromus inermis. Here we report cascading effects on soil chemistry, with increases in nitrate and acidity and consequent decreases in calcium content and cation exchange capacity. Bacterial and archaeal communities were more affected by Roundup Promax than eukaryotic communities, with decreases in phylogenetic diversity and changes in community structure following Roundup Promax applications, particularly after five applications. More critically, the colonization of plant roots by arbuscular mycorrhizal fungi decreased significantly in plots receiving even just two applications of Roundup Promax, and dark septate endophytes decreased after four applications. Our work shows that Roundup Promax had multiple negative effects on soil biota in this field study due to either direct effects or indirect effects mediated through plant removal. Our results suggest that repeated herbicide applications are especially damaging to soil health and microbe-plant associations. These effects in turn could severely hamper the ability of native plants to establish during ecosystem restoration projects.

LONG-LASTING APPROPRIATION SUCCESS OF AN INNOVATION? A COMPARATIVE CASE STUDY OF BAYER’S ASPIRIN AND ROUNDUP

Changes such as expiring patents and shifting environments challenge a firm trying to reach long-lasting appropriation success of an innovation. To understand how appropriation can be continued over time, this study investigates and compares Bayer’s two innovations, Aspirin medicine and Roundup herbicide. Whereas for the first, appropriation success has been continued through decades, for the latter, such a continuum has not realised. Our findings suggest that long-lasting appropriation success lies in adjusting the appropriation strategy by identifying the most substantial appropriability premises for innovation (appropriability mechanisms and complementary assets) and the ways to use them in different situations, paying specific attention to the shifting appropriability conditions. For long-term success, it is critical for firms to recognise that isolating appropriability mechanisms and complementary assets can have varied and distinctive implications depending on the pertinent contextual factors at innovation level and to strategise accordingly.

Effects of glyphosate herbicide Roundup® on antioxidant enzymes activity and detoxification-related gene expression in honey bees (Apis mellifera)

Glyphosate (GLY) is a type of broad-spectrum herbicide and has been widely used for weed control. In the past few decades, GLY was generally considered to be low toxic or non-toxic to animals. However, recent studies demonstrated that GLY has adverse effects on honey bees. How honey bees’ internal antioxidant and detoxification system responds to GLY exposure needs to be investigated. In this study, we calculated the median lethal dose (LD50) of GLY in honey bees and evaluate the effect of GLY on detoxification-related gene expression and antioxidant enzyme activities of honey bees. Our results showed that the LD50 of GLY to honey bees at 24 and 48 h were 1773.06 and 537.67 µg active ingredient (a.i.)/bee, respectively, which suggested the low toxicity of GLY to honey bees. Moreover, we found significantly downregulated enzyme activity of superoxide dismutase (SOD), upregulated activities of glutathione S-transferase (GST) and acetylcholinesterase (AChE), as well as upregulated gene expression of CYP9Q1 in the head, and CYP9Q2 in the head and abdomen, which indicated the important roles of GST, AChE, and cytochrome P450 monooxygenase (CYPs/P450s) in protecting bees against GLY stress. Our study will help to clarify the role of antioxidative enzymes and detoxifying enzymes in terms of preventing or limiting GLY stress injury.

The adverse impact of herbicide Roundup Ultra Plus in human spermatozoa plasma membrane is caused by its surfactant

The scarce research about the worldwide used glyphosate-based herbicide Roundup is controversial in human reproduction, especially spermatozoa. This study investigates the in vitro effect in human spermatozoa of Roundup Ultra Plus (RUP), its active ingredient glyphosate and its non-active, surfactant. Human spermatozoa were incubated (1 h, 37 °C) in presence/absence of RUP 0.01%, glyphosate, or equivalent surfactant concentration. Motility and sperm parameters were analyzed by C.A.S.A and flow cytometry, respectively. RUP significantly increases sperm plasma membrane lipid disorganization in a concentration-dependent manner while it decreases plasma membrane integrity. RUP significantly increases the death spermatozoa population after A23187-induced acrosome reaction, without affecting sperm viability, mitochondrial membrane potential, ROS content, acrosome membrane damage, phosphatidylserine exposure, A23187-induced acrosome reaction or GSK3 phosphorylation. RUP also significantly decreases motile and the a + b sperm populations. Interestingly, all sperm effects caused by RUP 0.01% are mimicked by its surfactant POEA at equivalent concentration. However, glyphosate does not affect any sperm parameter, even using 10-times higher concentration than the RUP 0.01% equivalent. RUP disturbs lipid organization and integrity of human sperm plasma membrane and reduces motility, without affecting viability or functional parameters. Importantly, RUP adverse effects in human spermatozoa are caused by the surfactant and no by glyphosate.

Lifelong Exposure to a Low-Dose of the Glyphosate-Based Herbicide RoundUp® Causes Intestinal Damage, Gut Dysbiosis, and Behavioral Changes in Mice.

RoundUp® (RUp) is a comercial formulation containing glyphosate (N-(phosphono-methyl) glycine), and is the world’s leading wide-spectrum herbicide used in agriculture. Supporters of the broad use of glyphosate-based herbicides (GBH) claim they are innocuous to humans, since the active compound acts on the inhibition of enzymes which are absent in human cells. However, the neurotoxic effects of GBH have already been shown in many animal models. Further, these formulations were shown to disrupt the microbiome of different species. Here, we investigated the effects of a lifelong exposure to low doses of the GBH-RUp on the gut environment, including morphological and microbiome changes. We also aimed to determine whether exposure to GBH-RUp could harm the developing brain and lead to behavioral changes in adult mice. To this end, animals were exposed to GBH-RUp in drinking water from pregnancy to adulthood. GBH-RUp-exposed mice had no changes in cognitive function, but developed impaired social behavior and increased repetitive behavior. GBH-Rup-exposed mice also showed an activation of phagocytic cells (Iba-1–positive) in the cortical brain tissue. GBH-RUp exposure caused increased mucus production and the infiltration of plama cells (CD138-positive), with a reduction in phagocytic cells. Long-term exposure to GBH-RUp also induced changes in intestinal integrity, as demonstrated by the altered expression of tight junction effector proteins (ZO-1 and ZO-2) and a change in the distribution of syndecan-1 proteoglycan. The herbicide also led to changes in the gut microbiome composition, which is also crucial for the establishment of the intestinal barrier. Altogether, our findings suggest that long-term GBH-RUp exposure leads to morphological and functional changes in the gut, which correlate with behavioral changes that are similar to those observed in patients with neurodevelopmental disorders.

In Vivo Estimation of the Biological Effects of Endocrine Disruptors in Rabbits after Combined and Long-Term Exposure: Study Protocol.

Recently, an increasing number of chemical compounds are being characterized as endocrine disruptors since they have been proven to interact with the endocrine system, which plays a crucial role in the maintenance of homeostasis. Glyphosate is the active substance of the herbicide Roundup®, bisphenol A (BPA) and di (2-ethylhexyl) phthalate (DEHP) are used as plasticizers, while triclosan (TCS), methyl (MePB), propyl (PrPB), and butyl (BuPB) parabens are used as antimicrobial agents and preservatives mainly in personal care products. Studies indicate that exposure to these substances can affect humans causing developmental problems and problems in the endocrine, reproductive, nervous, immune, and respiratory systems. Although there are copious studies related to these substances, there are few in vivo studies related to combined exposure to these endocrine disruptors. The aim of the present pilot study is the investigation and assessment of the above substances’ toxicity in rabbits after twelve months of exposure to glyphosate (both pure and commercial form) and to a mixture of all the above substances at subtoxic levels. The lack of data from the literature concerning rabbits’ exposure to these substances and the restrictions of the 3Rs Principle will result in a limited number of animals available for use (four animals per group, twenty animals in total).

A Comparison of Mechanical Versus Chemical Control of the Invasive Species Myrtle Spurge (Euphorbia myrsinites)

Myrtle spurge (Euphorbia myrsinites) is an invasive plant in North America that was introduced from Eurasia as a drought-tolerant ornamental. It has escaped cultivation and is widespread in western North America. Infestations can be reduced by either mechanical or chemical means, but the two approaches have not been compared directly. One study recommended mechanical treatment in the spring and chemical treatment in the fall, but neither recommendation was supported by data. To test the effectiveness of mechanical versus chemical treatment in the fall, we located six sites in the foothills of the Wasatch Mountains in Utah that were uniformly infested with myrtle spurge. At each of the sites we randomly assigned a 2.25 m2 quadrat to one of three treatments (i.e., mechanical, chemical, or control). The mechanical treatment entailed hand pulling and the chemical treatment involved applying the herbicide Roundup to each myrtle spurge. The controls were unmanipulated. We photographed each quadrat pretreatment and one year post-treatment. Both mechanical and chemical approaches significantly reduced the percent cover and stalk count of myrtle spurge compared to the controls. Additionally, the effects of the two treatments did not differ from each other. These results indicate that land managers can control myrtle spurge in the fall with either treatment and do not have to wait until the spring to employ mechanical methods. Mechanical removal of myrtle spurge is better suited to events that involve members of the general public such as “Purge Your Spurge” activities because they reduce the public's exposure to herbicide.

Sub-lethal effect of Round-up (a glyphosate-based herbicide) on juve-niles of African cat fish (Clarias gariepinus)

Herbicides have, no doubt, increased crop yields by killing different types of weeds, however, rainfall and irrigation can wash herbicides from sites of application into the water system. Fish has an important role in the food chain; therefore, investigation of the effects of Round-up on fish has a diag-nostic significance in evaluation of adverse effect of herbicides to human health. The sub-lethal effects of Round-up herbicide on juveniles of an Afri-can catfish Clarias gariepinus was investigated under laboratory conditions. The herbicide caused mortality of fish in a concentration dependent manner for the duration of exposure to acute concentrations (LC5O) of the herbicides for 96hrs.The lethal concentration (LC5O) value of glyphosate was gotten to be 0.560mg/1 for 96hr of exposure using Probit analysis. For the sub-lethal assay, standard haematological procedures were adopted to evaluate the blood parameters. There was significant reduction (p&lt;0.05) in WBC, HGC, RBC, Lymphocyte and Monocyte in order of concentrations with respect to the control. There was also a significance increase (P&lt;0.05) in MCV, MCH, MCHC and Platelet in order of concentration with respect to the control. The results of the biochemical properties showed that the level of total protein, glucose and total cholesterol were elevated with increase in concentration on exposure period of 8weeks compared to the control experiment(P&lt;0.05). This clearly shows that the values were dose-dependent. The result from this study shows that Round-up has a toxic effect on C. gariepinus. This toxicity can end up in humans through the food chain.

Herbicide Roundup shows toxic effects in nontarget organism Drosophila.

Glyphosate-based herbicide Roundup, as the most employed herbicide used for multiple purposes in agriculture, adversely affects nontarget organisms. We tested the effects of Roundup applied at larval and adult stages. Roundup caused developmental delay and increased larvae mortality. Roundup treatment reduced hemolymph glucose and glycogen levels in adult flies of both sexes at the highest concentration tested. Sex-dependent diverse effects were found in catalase and Cu,Zn superoxide dismutase (Cu,Zn-SOD) activities. Decreased aconitase activity, contents of thiols, and lipid peroxides were found after larval Roundup exposure. Furthermore, chronic exposure to adult flies decreased appetite, body weight, and shortened lifespan. Thus, our results suggest that high concentrations of Roundup are deleterious to both larvae and adults, resulting in a shift of the metabolism and antioxidant defense system in Drosophila melanogaster.