Comparative effects of the Roundup and glyphosate on mitochondrial oxidative phosphorylation

Effects of glyphosate on earthworms: From fears to facts

Glyphosate is the most widely applied herbicide worldwide, contaminating water, soils, and living organisms. Earthworms are emblematic soil organisms used as indicators of soil quality, but knowledge about the impacts of glyphosate and glyphosate-based herbicides (GBH) on these key soil organisms is scattered. Here, we examine this knowledge in detail to answer four questions: (1) Which endpoint is the most sensitive when assessing the effects of glyphosate or GBH in earthworms? (2) Which is most toxic to earthworms: glyphosate or GBH? (3) Are glyphosate and GBH harmful to earthworms when used at the recommended application dose? (4) What are the interactions between glyphosate or GBH and other chemicals in earthworms? The results indicate that a weak legislation led to improper assessment of the ecotoxicity of glyphosate during the last renewal in 2017. Our findings also highlighted that negative effects can occur in earthworms at the recommended application rate, although not after only a single application or when considering only the mortality of adult individuals. However, under more realistic conditions, that is, when assessing sensitive endpoints (e.g., reproduction, growth) and using species present in the field, after several applications per year, the negative effects of glyphosate or GBH on earthworms were observed at the subindividual, individual, population, and community levels, as well as on earthworm-mediated functions. Our recommendations are as follows: (i) competent agencies should collect more information on the toxicity of these compounds to earthworms before the next renewal deadline, with emphasis on the use of the updated legislation on the topic, and (ii) scientists should increase research on the effects of these herbicides on soil invertebrate species, with emphasis on earthworms, using guideline tests and obtain data from long-term field testing. Integr Environ Assess Manag 2024;20:1330-1336. © 2023 SETAC.

Bifenox induces hepatotoxicity and vascular toxicity in zebrafish embryos via ROS production and alterations in signaling pathways

Existing evidence shows that currently used pesticides pose toxicological risks to exposed wildlife. Chemically, bifenox belongs to diphenyl ethers, a well-known group of herbicides. Its mechanism of action primarily involves inducing lipid peroxidation and blocking protoporphyrinogen oxidases. Toxicity of diphenyl ether herbicides has been elucidated in animal cells; however, in vivo toxicological evaluations of bifenox are required to determine its unexpected effects. This study aimed to determine the negative effects of bifenox, and its effects on higher eukaryotes. We found that early stages of zebrafish embryo exposed to bifenox demonstrated increased mortality and physiological defects, based on the LC50 value. Bifenox severely inhibited blood vessel growth by reducing key elements of complex connectivity; fluorescently tagged transgenic lines (fli1a:EGFP) showed morphological changes. Additionally, transgenic lines that selectively identified hepatocytes (fabp10a:DsRed) showed reduced fluorescence, indicating that bifenox may inhibit liver development. To evaluate the level of oxidative stress, we used 2',7'-dichlorofluorescein diacetate (DCFH-DA) probes in zebrafish embryos to identify the underlying mechanisms causing developmental damage. Our findings demonstrate that exposure to bifenox causes abnormalities in the hepatic and cardiovascular systems during zebrafish embryogenesis. Therefore, this study provides new information for the evaluation of toxicological risks of bifenox in vertebrates.

The impact of the herbicide glyphosate and its metabolites AMPA and MPA on the metabolism and functions of human blood neutrophils and their sex-dependent effects on reactive oxygen species and CXCL8/IL-8 production

Significant levels of glyphosate, the world's most widely used herbicide, and its primary metabolites, AMPA and MPA, are detected in various human organs and body fluids, including blood. Several studies have associated the presence of glyphosate in humans with health problems, and effects on immune cells and their functions have been reported. However, the impact of this molecule and its metabolites on neutrophils, the most abundant leukocytes in the human bloodstream, is still poorly documented. We isolated neutrophils from human donor blood and investigated the effects of exposure to glyphosate, AMPA, and MPA on viability, energy metabolism, and essential antimicrobial functions in vitro. We observed that neutrophil viability was unaffected at the blood-relevant average concentrations of the general population and exposed workers, as well as at higher intoxication concentrations. Neutrophil energy metabolism was also not altered following exposure to the chemicals. However, while phagocytosis was unaffected, reactive oxygen species generation and CXCL8/IL-8 production were altered by exposure to the molecules. Alterations in function following exposure to glyphosate and metabolites differed according to the sex of the donors, which could be linked to glyphosate's known role as an endocrine disruptor. While ROS generation was increased in both sexes, male neutrophils exposed to glyphosate had increased intracellular production of CXCL8/IL-8, with no effect on female neutrophils. Conversely, exposure to the metabolites AMPA and MPA decreased extracellular production of this chemokine only in female neutrophils, with MPA also increasing intracellular production in male cells exposed to the chemoattractant N-formyl-methionine-leucyl-phenylalanine. Our study highlights the effects of glyphosate and its metabolites on the antimicrobial functions of neutrophils, which could be associated with health problems as future studies provide a better understanding of the risks associated with glyphosate use. Advances in knowledge will enable better and potentially stricter regulations to protect the public.

Changes in the proteome of Apis mellifera acutely exposed to sublethal dosage of glyphosate and imidacloprid

Uncontrolled use of pesticides has caused a dramatic reduction in the number of pollinators, including bees. Studies on the effects of pesticides on bees have reported effects on both metabolic and neurological levels under chronic exposure. In this study, variations in the differential expression of head and thorax-abdomen proteins in Africanized A. mellifera bees treated acutely with sublethal doses of glyphosate and imidacloprid were studied using a proteomic approach. A total of 92 proteins were detected, 49 of which were differentially expressed compared to those in the control group (47 downregulated and 2 upregulated). Protein interaction networks with differential protein expression ratios suggested that acute exposure of A. mellifera to sublethal doses of glyphosate could cause head damage, which is mainly associated with behavior and metabolism. Simultaneously, imidacloprid can cause damage associated with metabolism as well as, neuronal damage, cellular stress, and impairment of the detoxification system. Regarding the thorax-abdomen fractions, glyphosate could lead to cytoskeleton reorganization and a reduction in defense mechanisms, whereas imidacloprid could affect the coordination and impairment of the oxidative stress response.

Was the massive increase in use of teratogenic agrichemicals in western states (USA) associated with declines in wild ruminant populations between 1994 and 2013?

Population declines were documented in multiple ruminant species in Montana and surrounding states starting in 1995. While weather, food sources, and predation certainly contributed, the declines were often attributed, at least partly, to unexplained factors. Use of teratogenic agrichemicals, notably neonicotinoid insecticides, fungicides, and glyphosate-based herbicides, massively increased regionally in 1994-96. The question explored in this review is whether this vastly increased use of these teratogenic pesticides might have contributed to observed population declines. We provide references and data documenting that specific developmental malformations on vertebrates can be associated with exposure to one or more of these agrichemicals. These pesticides are known to disrupt thyroid and other hormonal functions, mitochondrial functions, and biomineralization, all of which are particularly harmful to developing fetuses. Exposures can manifest as impaired embryonic development of craniofacial features, internal and reproductive organs, and musculoskeletal/integumental systems, often resulting in reproductive failure or weakened neonates. This paper reviews: a) studies of ruminant populations in the region, especially elk and white-tailed deer, prior to and after 1994; b) published and new data on underdeveloped facial bones in regional ruminants; c) published and new data on reproductive abnormalities in live and necropsied animals before and after 1994; and d) studies documenting the effects of exposures to three of the most applied teratogenic chemicals. While answers to the question posed above are complex and insufficient evidence is available for definitive answers, this review provides ideas for further consideration.

Associations between urine glyphosate levels and metabolic health risks: insights from a large cross-sectional population-based study

BACKGROUND

The prevalence of metabolic syndrome (MetS) in American adults increased from 37.6% in the 2011-12 period to 41.8% in 2017-2018. Environmental exposure, particularly to common compounds such as glyphosate, has drawn increasing attention as a potential risk factor.

METHODS

We employed three cycles of data (2013-2018) from the National Health and Nutrition Examination Survey (NHANES) in a cross-sectional study to examine potential associations between urine glyphosate measurements and MetS incidence. We first created a MetS score using exploratory factor analysis (EFA) of the International Diabetes Federation (IDF) criteria for MetS, with data drawn from the 2013-2018 NHANES cycles, and validated this score independently on an additional associated metric, the albumin-to-creatinine (ACR) ratio. The score was validated via a machine learning approach in predicting the ACR score via binary classification and then used in multivariable regression to test the association between quartile-categorized glyphosate exposure and the MetS score.

RESULTS

In adjusted multivariable regressions, regressions between quartile-categorized glyphosate exposure and MetS score showed a significant inverted U-shaped or saturating dose‒response profile, often with the largest effect for exposures in quartile 3. Exploration of potential effect modification by sex, race, and age category revealed significant differences by race and age, with older people (aged > 65 years) and non-Hispanic African American participants showing larger effect sizes for all exposure quartiles.

CONCLUSIONS

We found that urinary glyphosate concentration is significantly associated with a statistical score designed to predict MetS status and that dose-response coefficient is nonlinear, with advanced age and non-Hispanic African American, Mexican American and other Hispanic participants exhibiting greater effect sizes.

Glyphosate contamination of drinking water and the occurrence of oxidative stress: Exposure assessment to rural Brazilian populations

Studies reported that continuous application of glyphosate can cause disturbance in aquatic/terrestrial environments. As such, the objective of this study is to discuss the risk of exposure to the herbicide in drinking water and to assess the oxidative stress in the consumers rural populations of Casimiro de Abreu/ RJ and Paraguaçu/ MG, Brazil. For this, water samples (n=69) were analysed from the home of volunteers, by FMOC derivatizing- LC-FLD method. The oxidative stress was analysed determining lipid peroxidation (MAD) and defense enzymes (SOD and CAT) in serum samples from rural population (n=42) compared to urban residents (n= 42). Results of the analysis from drinking water, despite the low and moderate risk, by the hazard quotient (HQ), revealed that the population is environmentally exposed to the glyphosate. The relevant findings showed that is important to implement monitoring/ biomonitoring programs to prevent pollution and toxic effects in the rural populations.

Exfoliation of a Coordination Polymer Based on a Linear π-Conjugated Ligand into an Ultrathin Nanosheet for Glyphosate Sensing

Owing to the large-scale consumption of pesticides and their potential threats to the environment and human health, the development of sensing materials for pesticides has attracted considerable attention in recent years. In this work, a novel Cd(II)-based coordination polymer (CP) with the formula [Cd(H2O)2(L)]·DMF (Cd-1, DMF = N,N-dimethylformamide, H2L = 4,4'-[(2,5-dimethoxy-1,4-phenylene)di-2,1-ethenediyl]bis-benzoic acid) was synthesized under solvothermal conditions. Structural analysis revealed that coordination between central Cd2+ cations and the ligand L2- formed two-dimensional (2D) networks, which were further assembled by noncovalent hydrogen bonds into a three-dimensional (3D) supramolecular framework. Through ultrasonic treatment in isopropyl alcohol, Cd-1 was exfoliated to afford an ultrathin CP-based 2D nanosheet (Cd-1-NS) with a thickness of less than 1.8 nm. Compared to the bulk materials, the prepared Cd-1-NS exhibited enhanced fluorescence emission properties and superior sensing performance toward glyphosate (Glyph) in water with high selectivity, sensitivity, anti-interference, fast response, and good recyclability via the turn-off effect. The limit of detection (LOD) of Cd-1-NS for Glyph was as low as 41 nM (7 ppb) in the low-concentration range of 0-2.4 μM. In addition, the Cd-1-NS also showed excellent practicability and reliability for the detection of Glyph in real samples, including lake water, tap water, cabbage, and watermelon skin, and could realize the rapid visualized sensing of Glyph residues on the surfaces of vegetables and fruits.

Associations between urinary glyphosate and diabetes mellitus in the US general adult: a cross-sectional study from NHANES 2013-2016

Glyphosate-based herbicides (GBHs) are used extensively around the world and have become the leading agrochemicals. However, study about the association between glyphosate exposure and the risk of diabetes mellitus (DM) is scarce. This study used 4 years of NHANES data (2013-2016) to further investigate the association. A total of 2535 participants were enrolled in this cross-sectional study. The baseline information and urinary glyphosate levels in diabetic and non-diabetic groups were compared. Using multivariable logistic regression mode, we explored the association between both the continuous and categorical forms of urinary glyphosate and DM risk. Further subgroup analyses based on categorical covariates were also conducted. Urinary glyphosate levels were 0.42 ng/ml in participants with diabetes and 0.34 ng/ml in participants without diabetes (P < 0.05). As a continuous variable, ln-transformed urinary glyphosate was significantly associated with an increased risk of DM in the most adjusted model (OR 1.28, 95% CI 1.03-1.57). However, the association was not significant in the most adjusted categorical model (P > 0.05).In further subgroup analyses, the associations remained significant in several subgroups. This study provides new evidence that glyphosate exposure was associated with a higher risk of diabetes in the American general adult population.

Effects of glyphosate, mancozeb and their combinations on mouse neuroblastoma cells

Pesticides-related toxicities have long been studied. Data regarding the effects of combined exposure to environmentally relevant pesticides however remain lacking. The herbicide glyphosate and the fungicide mancozeb are extensively used in agriculture. Residues of both compounds are frequently found in food and water and therefore, environmental exposure to both pesticides is a possibility. Neurotoxicity of glyphosate, mancozeb and their combinations were investigated using mouse neuroblastoma cells. Cytotoxicity observed with the glyphosate and mancozeb combinations was higher than that observed when glyphosate was tested alone. Combinations of glyphosate followed by mancozeb increased copper, manganese, and zinc levels. Mixture of mancozeb + glyphosate increased manganese and zinc levels. Combination of mancozeb followed by glyphosate increased copper and zinc levels. Glutathione ratio was decreased as a result of combinations of glyphosate and mancozeb. The decrease in glutathione ratio was greater in the combination groups than in glyphosate alone.

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 10.16 mg L-1. The experimental fish were subjected to three sub-lethal concentrations of 2.06, 1.03, and 0.63 mg l-1 for 28 days 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 possible assessment 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.

Cytotoxic and genotoxic profiles of the pyrethroid insecticide lambda-cyhalothrin and its microformulation Karate® in CHO-K1 cells

Lambda-cyhalothrin (LCT) and its microformulation Karate® (25 % a.i.) were analysed for its genotoxicity and cytotoxicity on Chinese hamster ovary (CHO-K1) cells. Cytokinesis-block micronucleus cytome (CBMN-cyt) and alkaline single-cell gel electrophoresis (SCGE) bioassays were selected to test genotoxicity. Neutral red uptake (NRU), succinic dehydrogenase activity (MTT) and apoptogenic induction were employed for estimating cytotoxicity. Both compounds were analysed within a concentration range of 0.1-100 µg/mL. Only LCT produced a significant augment in the frequency of micronuclei (MNs) when the cultures were exposed to highest concentrations of 10 and 100 µg LCT/mL. A noticeable decrease in NDI was observed for cultures treated with LCT at 10 and 100 µg/mL. Karate® induced the inhibition of both the proportion of viable cells and succinic dehydrogenase activity and triggered apoptosis 24 h of exposition. Whilst an increased GDI in CHO-K1 cells was observed in the treatments with 1-100 µg Karate®/mL, the GDI was not modified in the treatments employing LCT at equivalent doses. SCGE showed that Karate® was more prone to induce genotoxic effects than LCT. Only 50 µg/mL of Karate® was able to increase apoptosis. Our results demonstrate the genomic instability and cytotoxic effects induced by this pyrethroid insecticide, confirming that LCT exposure can result in a severe drawback for the ecological equilibrium of the environment.

Changes in the morphology and cell ultrastructure of a microalgal community exposed to a commercial glyphosate formulation and a toxigenic cyanobacterium

Human activities significantly influence the health of aquatic ecosystems because many noxious chemical wastes are discharged into freshwater bodies. Intensive agriculture contributes to the deterioration by providing indirectly fertilizers, pesticides, and other agrochemicals that affect the aquatic biota. Glyphosate is one of the most used herbicides worldwide, and microalgae are particularly sensitive to its formulation, inducing displacement of some green microalgae from the phytoplankton that leads to alterations in the floristic composition, which fosters the abundance of cyanobacteria, some of which can be toxigenic. The combination of chemical stressors such as glyphosate and biological ones, like cyanotoxins and other secondary metabolites of cyanobacteria, could induce a combined effect potentially more noxious to microalgae, affecting not only their growth but also their physiology and morphology. In this study, we evaluated the combined effect of glyphosate (Faena^®) and a toxigenic cyanobacterium on the morphology and ultrastructure of microalgae in an experimental phytoplankton community. For this purpose, Microcystis aeruginosa (a cosmopolitan cyanobacterium that forms harmful blooms) and the microalgae Ankistrodesmus falcatus, Chlorella vulgaris, Pseudokirchneriella subcapitata, and Scenedesmus incrassatulus were cultivated, individually and jointly, exposing them to sub-inhibitory concentrations of glyphosate (IC₁₀, IC_20, and IC₄₀). Effects were evaluated through scanning electron (SEM) and transmission electron (TEM) microscopy. Exposure to Faena^® produced alterations in the external morphology and ultrastructure of microalgae both individually and in combined cultures. SEM evidenced the loss of the typical shape and integrity of the cell wall and an increase in the biovolume. TEM revealed reduction and disorganization of the chloroplast, variation in starch and polyphosphate granules, formation of vesicles and vacuoles, cytoplasm degradation, and cell wall continuity loss. The presence of M. aeruginosa was, for microalgae, an additional stress factor adding to the chemical stress produced by Faena^®, increasing the damage in their morphology and ultrastructure. These results alert to the effects that can be caused by glyphosate and the presence of toxigenic bacteria on the algal phytoplankton in contaminated and anthropic and eutrophic freshwater ecosystems.

Investigating the effects of glyphosate on the bumblebee proteome and microbiota

Glyphosate is one of the most widely used herbicides globally. It acts by inhibiting an enzyme in an aromatic amino acid synthesis pathway specific to plants and microbes, leading to the view that it poses no risk to other organisms. However, there is growing concern that glyphosate is associated with health effects in humans and an ever-increasing body of evidence that suggests potential deleterious effects on other animals including pollinating insects such as bees. Although pesticides have long been considered a factor in the decline of wild bee populations, most research on bees has focussed on demonstrating and understanding the effects of insecticides. To assess whether glyphosate poses a risk to bees, we characterised changes in survival, behaviour, sucrose solution consumption, the digestive tract proteome, and the microbiota in the bumblebee Bombus terrestris after chronic exposure to field relevant doses of technical grade glyphosate or the glyphosate-based formulation, RoundUp Optima+®. Regardless of source, there were changes in response to glyphosate exposure in important cellular and physiological processes in the digestive tract of B. terrestris, with proteins associated with oxidative stress regulation, metabolism, cellular adhesion, the extracellular matrix, and various signalling pathways altered. Interestingly, proteins associated with endocytosis, oxidative phosphorylation, the TCA cycle, and carbohydrate, lipid, and amino acid metabolism were differentially altered depending on whether the exposure source was glyphosate alone or RoundUp Optima+®. In addition, there were alterations to the digestive tract microbiota of bees depending on the glyphosate source No impacts on survival, behaviour, or food consumption were observed. Our research provides insights into the potential mode of action and consequences of glyphosate exposure at the molecular, cellular and organismal level in bumblebees and highlights issues with the current honeybee-centric risk assessment of pesticides and their formulations, where the impact of co-formulants on non-target organisms are generally overlooked.

Toxicity of POEA-containing glyphosate-based herbicides to amphibians is mainly due to the surfactant, not to the active ingredient

Current international legislation regarding agrochemicals requires thorough toxicological testing mainly of the active ingredients. In a 96-h acute toxicity test we exposed Rana dalmatina and Bufo bufo tadpoles to either one of three concentrations of glyphosate, three concentrations of the surfactant (POEA), three concentrations of the two components together, or to non-contaminated water (control), and subsequently assessed mortality and body mass. To investigate whether simultaneous exposure to another stress factor influences effects of the contaminants, we performed tests both in the presence or absence of predator chemical cues. We found that the surfactant had significant harmful effects on tadpoles; survival was lowered by the highest concentration of the surfactant in case of R. dalmatina, while in B. bufo tadpoles it reduced survival already at medium concentrations. Body mass was significantly influenced by medium and high surfactant concentrations in both species. The presence of glyphosate did not have a significant effect by itself, but it slightly increased mortality in tadpoles exposed to medium concentrations of the surfactant in both species. The presence of chemical cues did not have an effect on the examined variables. Our study confirms that the toxicity of glyphosate-based herbicides is mainly due to the examined surfactant. Nonetheless, we found that glyphosate can enhance the harmful effect of the surfactant. These results stress that during the authorization process of new pesticide formulations, not only the active ingredients would need to be examined but the excipients should also be taken into account in an obligatory and systematic manner.

The role of surface activity on the amyloid fibrillation pathway of bovine serum albumin upon interaction with glyphosate

As an active ingredient in its derivative products, glyphosate has emerged as the most widespread herbicide in recent decades. Bovine serum albumin (BSA) as a carrier protein may be adversely affected by structural changes due to binding affinity with glyphosate, which may lead to dysfunctionality or metabolic disorders. This study aimed to investigate the interaction of glyphosate with BSA and its thermal fibrillation pathway employing techniques such as dynamic surface tension, fluorescence quenching, ThT binding, circular dichroism spectroscopy, and reactive oxygen species (ROS) measurement, as well as molecular dynamics (MD) studies. The adsorption dynamic analysis suggested hydrophobic moiety at higher concentrations of glyphosate upon interaction with BSA. MD results suggested a slight fluctuation due to glyphosate interaction with protein molecules. The carboxy group presented in glyphosate made a hydrogen bond with the hydroxyl group of TYR¹⁴⁷. The fluorescence quenching and diffusion studies approved BSA's increased unfolding and hydrophobicity resulting from glyphosate interaction, which would induce fibrillation/aggregation, according to our fibrillation kinetics data. The surface activity of glyphosate at higher concentrations and its approved involvement in structural changes of BSA through hydrogen bonding may raise concerns about its potential side effect on farm animals and the food cycle.

The aquatic macrophyte Salvinia molesta mitigates herbicides (glyphosate and aminomethylphosphonic acid) effects to aquatic invertebrates

We evaluated the individual and combined effects of different environmentally representative concentrations of glyphosate (0, 25, 50, 75, and 100 µg l^-1) and aminomethylphosphonic acid (AMPA; 0, 12.5, 25, 37.5, and 50 µg l^-1) on the physiology of Aedes aegypti larvae, as well as the capacity of the aquatic macrophyte Salvinia molesta to attenuate those compounds' toxicological effects. Larvae of Ae. aegypti (between the third and fourth larval stages) were exposed for 48 h to glyphosate and/or AMPA in the presence or absence of S. molesta. Glyphosate and AMPA induced sublethal responses in Ae. aegypti larvae during acute exposures. Plants removed up to 49% of the glyphosate and 25% of AMPA from the water, resulting in the exposure of larvae to lower concentration of those compounds in relation to media without plants. As a result, lesser effects of glyphosate and/or AMPA were observed on larval acetylcholinesterase, P450 reductase, superoxide dismutase, mitochondrial electron transport chain enzymes, respiration rates, and lipid peroxidation. In addition to evidence of deleterious effects by media contamination with glyphosate and AMPA on aquatic invertebrates, our results attest to the ability of S. molesta plants to mitigate the toxicological impacts of those contaminants.

Glyphosate-Based Herbicide Causes Cellular Alterations to Gut Epithelium of the Neotropical Stingless Bee Melipona quadrifasciata quadrifasciata (Hymenoptera: Meliponini)

Glyphosate-based herbicides (GBH) are the best-selling pesticides in Brazil, with hundreds of thousands of tons sold per year. There is no study investigating morphological alterations caused by GBH on the epithelium of the gut in bees. Here, we aimed to demonstrate effects of chronic ingestion of GBH in the midgut digestive cells of the Brazilian stingless bee Melipona quadrifasciata quadrifasciata Lepeletier 1836. We kept forager workers of M. quadrifasciata in laboratory conditions and fed on food contaminated with three different concentrations of GBH for 10 days, after which the midgut digestive cell structure and ultrastructure were analyzed. The presence of GBH in food did not affect food consumption, indicating that M. quadrifasciata bees do not reject food contaminated with GBH. As digestive cells of the midgut release apocrine secretion as a detoxication mechanism, we expected that the ingestion of food contaminated with GBH in the present study affect the height of midgut digestive cells. However, such reduction did not occur, probably because of the low-test concentrations. Although there were differences in digestive cell ultrastructure, ingestion of GBH impaired midgut digestive cell cohesion by disorganizing the smooth septate junctions between cells, which may probably be caused by the adjuvant "polyethoxylated tallow amine" present in the GBH. Previous studies demonstrated that GBH increase bees' sensibility to intestine infections, based on the present results we hypothesized that the loss of cell cohesion in the midgut epithelium favors pathogenic microbial infections and harms food absorption, increasing bees' mortality.

Effects of glyphosate and glyphosate-based herbicides like Roundup™ on the mammalian nervous system: A review

Glyphosate is the active ingredient in glyphosate-based herbicides (GBHs), such as Roundup™, the most widely used herbicides in the world. Glyphosate targets an essential enzyme in plants that is not found in animals. However, both glyphosate and GBHs are rated as Group 2A, probable human carcinogens, and also have documented effects on reproduction, acting as endocrine disruptive chemicals. We have reviewed reports of the effects of glyphosate and GBHs on mammalian nervous system function. As with several other herbicides, GBHs exposure has been associated with an increased risk of Parkinson's Disease and death of neurons in the substantia nigra. There is also some evidence implicating Roundup™ in elevated risk of autism. Other studies have shown the effects of GBHs on synaptic transmission in animal and cellular studies. The major mechanism of action appears to be oxidative stress, accompanied by mitochondrial dysfunction. In addition, some gut bacteria utilize the enzyme used by plants, and glyphosate and GBHs use has been shown to alter the gut microbiome. There is a large and growing body of evidence that the gut microbiome alters susceptibility to great number of human diseases, including nervous system function. The weight of the evidence indicates that in addition to cancer and reproductive effects, glyphosate and GBHs have significant adverse effects on the brain and behavior and increase the risk of at least some serious neurological diseases.

Effects of the herbicide glyphosate on fish from embryos to adults: a review addressing behavior patterns and mechanisms behind them

The use of agrochemicals has grown in recent years following the increase in agricultural productivity, to eliminate weeds that can compromise crop yields. The intensive use of these products combined with the lack of treatment of agricultural wastewater is causing contamination of the natural environments, especially the aquatics. Glyphosate [N-(phosphonomethyl) glycine] is the most commonly used herbicide in agriculture worldwide. Studies have shown that this compound is toxic to a variety of fish species at the concentrations of environmental relevance. Glyphosate-based herbicides can affect fish biochemical, physiological, endocrine, and behavioral pathways. Changes in behaviors such as foraging, escaping from predators, and courtship can compromise the survival of species and even communities. The behavior patterns of fish has been shown to be a sensitive tool for risk assessment. In this sense, this review summarizes and discusses the toxic effects of glyphosate and its formulations on the behavior of fish in different life stages. Additionally, behavioral impairments were associated with other negative effects of glyphosate such as energy imbalance, stress responses, AChE inhibition, and physiological and endocrine disturbances, which are evidenced and described in the literature. Graphical abstract.

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.

Toxic Effects of Glyphosate on the Nervous System: A Systematic Review

Glyphosate, a non-selective systemic biocide with broad-spectrum activity, is the most widely used herbicide in the world. It can persist in the environment for days or months, and its intensive and large-scale use can constitute a major environmental and health problem. In this systematic review, we investigate the current state of our knowledge related to the effects of this pesticide on the nervous system of various animal species and humans. The information provided indicates that exposure to glyphosate or its commercial formulations induces several neurotoxic effects. It has been shown that exposure to this pesticide during the early stages of life can seriously affect normal cell development by deregulating some of the signaling pathways involved in this process, leading to alterations in differentiation, neuronal growth, and myelination. Glyphosate also seems to exert a significant toxic effect on neurotransmission and to induce oxidative stress, neuroinflammation and mitochondrial dysfunction, processes that lead to neuronal death due to autophagy, necrosis, or apoptosis, as well as the appearance of behavioral and motor disorders. The doses of glyphosate that produce these neurotoxic effects vary widely but are lower than the limits set by regulatory agencies. Although there are important discrepancies between the analyzed findings, it is unequivocal that exposure to glyphosate produces important alterations in the structure and function of the nervous system of humans, rodents, fish, and invertebrates.

The effects of low-toxic herbicide Roundup and glyphosate on mitochondria

The effects of pesticides on the health of non-target living organisms in agricultural areas are critically important aspects for their safe use. Their release into the environment is an inevitable aspect for predicting and evaluation of the risk of their application. Roundup, a glyphosate-based herbicide, has been designed as an effective pesticide against weeds and now is the most widely used agrochemicals around the world due to its highly specific action of the biosynthesis of certain amino acids in plants. Despite it is claimed to be low toxic for not-target organisms, due to its broad application Roundup and products of its degradation were detected in organisms of diverse animals and humans. In this review, we describe animal and human studies of general adverse effects of Roundup and its principal substance glyphosate with focus on endocrine disruption, oxidative stress and behavioral disorders. At mechanistic level, we focus on the potential toxicity of the herbicide Roundup and glyphosate as effectors of bioenergetic functions of mitochondria. Their effects on mitochondrial membrane potential and oxidative phosphorylation are among described to date critical components responsible for its toxicity. Finally, we discuss general molecular mechanisms potentially involved in the interaction between glyphosate and mitochondria which to some extent are associated with generation of reactive oxygen species.

Impact of glyphosate and its formulation Roundup® on stallion spermatozoa

The growing and widespread use of glyphosate-based herbicides (GBHs) has raised an intense public debate about the impact of environmental contamination on animal and human health, including male fertility. The aim of this study was to deepen the impact of glyphosate (Gly) and GBHs on mammalian sperm investigating the effect of in vitro exposure of stallion spermatozoa to Gly and to its commercial formulation Roundup® (R). Spermatozoa were incubated at 37 °C with different Gly or R concentrations (from 0.5 to 720 μg/mL Gly or R at the same Gly-equivalent concentrations). After 1 h of incubation motility, viability, acrosome integrity, mitochondrial activity and ROS production were assessed. Gly, at all the concentrations tested, did not induce any detrimental impact on the sperm quality parameters evaluated. Conversely, R starting from 360 μg/mL (Gly-equivalent dose) significantly (P < 0.05) decreased total and progressive motility, viability, acrosome integrity, mitochondrial activity and the percentage of live spermatozoa with intact mitochondria not producing ROS. Our results indicate that the commercial formulation R is more toxic than its active molecule Gly and that the negative impact on stallion sperm motility might be likely due to a detrimental effect mainly at membrane and mitochondrial level and, at least in part, to redox unbalance. Moreover, based on the data obtained, it can be hypothesized a species-specificity in sperm sensitivity to Gly and GBHs as horse spermatozoa were negatively influenced at higher concentrations of R compared to those reported in literature to be toxic for human and swine male germ cells.

Generational effects of a chronic exposure to a low environmentally relevant concentration of glyphosate on rainbow trout, Oncorhynchus mykiss

In the past few decades, glyphosate became the most used herbicide substance worldwide. As a result, the substance is ubiquitous in surface waters. Concerns have been raised about its ecotoxicological impact, but little is known about its generational toxicity. In this study, we investigate the impact of an environmentally relevant concentration of glyphosate and its co-formulants on an F2 generation issued from exposed generations F0 and F1. Trans, inter and multigenerational toxicity of 1 μgL-1 of the active substance was evaluated on early stages of development and juvenile rainbow trout (Oncorhynchus mykiss) using different molecular, biochemical, immuno-hematologic, and biometric parameters, behavior analysis, and a viral challenge. Reproductive parameters of generation F1 were not affected. However, developmental toxicity in generation F2 due to glyphosate alone or co-formulated was observed with head size changes (e.g. head surface up to +10%), and metabolic disruptions (e.g. 35% reduction in cytochrome-c-oxidase). Moreover, larvae exposed transgenerationally to Viaglif and intergenerationally to glyphosate and Roundup presented a reduced response to light, potentially indicating altered escape behavior. Overall methylation was, however, not altered and further experiments using gene-specific DNA metylation analyses are required. After several months, biochemical parameters measured in juvenile fish were no longer impacted, only intergenerational exposure to glyphosate drastically increased the susceptibility of rainbow trout to hematopoietic necrosis virus. This result might be due to a lower antibody response in exposed fish. In conclusion, our results show that generational exposure to glyphosate induces developmental toxicity and increases viral susceptibility. Co-formulants present in glyphosate-based herbicides can modulate the toxicity of the active substance. Further investigations are required to study the specific mechanisms of transmission but our results suggest that both non-genetic mechanisms and exposure during germinal stage could be involved.

Biomarkers of exposure and effect in the armoured catfish Hoplosternum littorale during a rice production cycle

Fish cultivation in rice fields is a valuable resource in some rural areas of the world. Fish is a source of protein and an additional source of income for local farmers. However, the use of pesticides may impact fish and consumer health. The aim of this study was to evaluate exposure and effect biomarkers in native fish inhabiting a rice field during a production cycle. Samples of fish, water and sediment from a rice field in Santa Fe, Argentina were collected during a cultivation season (at the beginning: November 2017, in the middle: December 2017 and at the end: February 2018). At each sampling period, fish biomarkers of effect (biometric indices, hematological parameters, energy reserves, oxidative stress and neurotoxicity) were assessed together with pesticide screening in water, sediment, and fish samples. Only herbicides were present in water and sediment samples in agreement with land treatment before rice sowing stage, where only herbicides were applied. In general, the greatest water concentrations of bentazone, glyphosate and aminomethylphosphonic acid (AMPA), and the lowest sediment glyphosate and AMPA levels were observed at the beginning of the farming cycle. Fish bioaccumulated AMPA residues at all sampling periods and showed biological responses to cope with a stressful environment. Alterations in hematological parameters, mobilization of energetic reserves and activation of the antioxidant system were detected. However, no oxidative damage nor neurotoxic effects were present along the production cycle. Under a real exposure scenario, the present work demonstrates that biological changes are induced in fish to cope with stressors present in a rice field. Fish-rice coculture is an efficient and ecologically sustainable approach to increase food supplies, and a better understanding of the effect of this particular environment on fish would allow a greater and safer development of this promising productive activity in South American rice producing countries.

Hiding in Plain Sight: Modern Thiamine Deficiency

Thiamine or vitamin B1 is an essential, water-soluble vitamin required for mitochondrial energetics—the production of adenosine triphosphate (ATP). It is a critical and rate-limiting cofactor to multiple enzymes involved in this process, including those at the entry points and at critical junctures for the glucose, fatty acid, and amino acid pathways. It has a very short half-life, limited storage capacity, and is susceptible to degradation and depletion by a number of products that epitomize modern life, including environmental and pharmaceutical chemicals. The RDA for thiamine is 1.1–1.2 mg for adult females and males, respectively. With an average diet, even a poor one, it is not difficult to meet that daily requirement, and yet, measurable thiamine deficiency has been observed across multiple patient populations with incidence rates ranging from 20% to over 90% depending upon the study. This suggests that the RDA requirement may be insufficient to meet the demands of modern living. Inasmuch as thiamine deficiency syndromes pose great risk of chronic morbidity, and if left untreated, mortality, a more comprehensive understanding thiamine chemistry, relative to energy production, modern living, and disease, may prove useful.

Ameliorative effect of N-acetylcysteine against glyphosate-induced hepatotoxicity in adult male albino rats: histopathological, biochemical, and molecular studies

Glyphosate (GLP) is the most commonly used herbicide that presents many hazards to the environment and living organisms. The present study aimed to explore hepatotoxic properties of GLP on adult albino rats, and the ability of N-acetylcysteine (NAC) to ameliorate these toxic effects. Thirty mature male albino rats were distributed into 3 groups (10 rats/group): Group I (C) a negative control, Group II (GLP) orally administered Roundup 0.8503 ml/kg/day which contain GLP (375 mg/kg) (1/10 of LD50) by gavage needle, and Group III (NAC+ GLP) received NAC (160 mg/kg, 1h before Roundup) by gavage needle and Roundup (0.8503 ml/kg) orally for 6 weeks. Blood and liver samples were collected and processed for biochemical, histopathological, ultrastructural, and immunohistochemical investigations. Group II displayed a significant elevation of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and malondialdehyde (MDA) levels, as well as overexpression of apoptotic markers. The total antioxidant capacity "TAC" and mRNA expression of NRF2 were significantly decreased. Concerning the histopathological findings, there were various degenerative changes as the hepatocytes showed hydropic swelling with nuclear pyknosis. These alterations were confirmed ultrastructurally as most of the cytoplasmic organelles were lost and the mitochondria appeared to deteriorate. Immunohistochemical results showed intense immunoreactivity against proliferating cell nuclear antigen (PCNA) and caspase-3. NAC administration before GLP partially ameliorates these alterations. ALT, AST, and MDA levels as well as expression of apoptotic markers were significantly reduced. TAC and mRNA expression of NRF2 were significantly increased. Histopathological alterations were partially improved as the hepatocytes returned normal and ultrastructurally they showed nearly normal cytoplasmic organelles. Additionally, the intense expression of PCNA and caspase-3 was significantly reduced. We concluded that NAC can ameliorate most of the adverse effects of GLP exposure through its antioxidant property and free radicals scavenging capacity.

Reproductive toxicity of Roundup WG® herbicide: impairments in ovarian follicles of model organism Danio rerio

Glyphosate-based herbicides are widely used in global agriculture, and their effects on different non-target animal organisms have been the focus of many toxicological studies. Regarding the potential role of glyphosate-based herbicides as an endocrine disruptor, the present study aims to investigate the effects of the herbicide Roundup WG® (RWG) on female reproduction, specifically on the ovarian maturation of Danio rerio. Adult females were exposed to low concentrations of RWG (0.065, 0.65, and 6.5 mg L^-1) for 15 days, and then the ovaries were submitted to structural and morphometric procedures, accompanied by analysis of the vitellin protein content. Our results showed an increase of initial ovarian follicle numbers, decrease of late ovarian follicles, and smaller diameter of ovarian follicles in fish exposed to 0.065 and 6.5 mg L^-1. The thickness of vitelline envelope was reduced, and the vitellin protein content was increased in the ovarian follicle in the two highest concentrations. Ultrastructural changes in the ovarian follicular component were evident and expressed by the cell index; vacuolization in follicular cells, increase of perivitelline space, and impaired mitochondria in oocytes were observed. Therefore, RWG adversely affects the ovarian maturation in D. rerio, and these changes can lead to reproductive toxicity, compromising population dynamics.

The use of combined high-fructose diet and glyphosate to model rats type 2 diabetes symptomatology

An ideal food-chemical combination that will promote insulin resistance and its consequent development of pancreatic beta-cell dysfunction may open a new vista for Type 2 diabetes (T2D) research. Thus, we investigated the modulatory effects of a high-fructose diet (FRC) combined with glyphosate (GP). Male albino Wistar rats were randomly divided into five groups of eight/group and received distilled water, FRC, GP, and their combinations orally for eight consecutive weeks. We assessed the changes in fasting blood glucose levels (FBGLs), biochemical indices, oxidative stress parameters, and organ histopathology. From the results obtained, FBGLs and serum insulin levels were increased in the FRC-GP (2.3-3.1 and 1.9-2.2 folds) treated rats compared with the control baseline group. Also, the FRC-GP high dose increased FBGLs (1.9 folds), insulin (1.4 folds), triglycerides (1.5 folds), and uric acid (2 folds) levels compared with the FRC group. Malondialdehyde levels increased in the pancreas (54% and 78%) and liver (31.3% and 56.6%) of the FRC-GP treated rats. The FRC-GP treatments reduced serum high-density lipoprotein (57%), total protein (47%), and antioxidant parameters (non-enzymatic and enzymatic, 1.6-1.9 folds) respectively in the treated animals. The weight of the pancreas relative to the body increased (2-3 folds) while we observed mild inflammation and vascular congestion in vital organs in the treated rats. Overall, these results demonstrate the potential of FRC-GP-diet to induce conditions of rats T2D. Also, this novel finding suggests a cost-effective GP as an alternative in this model type and provides further insight into understanding FRC-GP interactions.

Ecotoxicological Studies on the Effect of Roundup® (Glyphosate Formulation) on Marine Benthic Microalgae

Glyphosate is a very effective herbicide and the main active ingredient in Roundup®-the most extensively used herbicide in the world. Since glyphosate is highly water soluble it reaches water bodies easily in surface water runoff. This prompted us to undertake an experiment to evaluate the effects of glyphosate in Roundup® on natural communities of marine microphytobenthos. Microphytobenthos communities were obtained from the environment, and after transporting them to the laboratory and acclimatizing them, they were tested under controlled conditions. Changes in microphytobenthos composition and structure and the deteriorating condition of the cells of community-forming organisms (assessed by analyzing changes in chloroplast shape) were used to assess the impact of Roundup® on endpoints. The tests indicated that microphytobenthic communities were relatively resistant to herbicide. The species richness of the communities probably enabled them to rebuild effectively. Sensitive species were replaced by those more tolerant of glyphosate. Only at the highest glyphosate concentration (8.5 g·dm-3) tested was a strong negative effect noted that limited community abundance and eliminated some of the organisms. The dominant diatoms in the communities were replaced by intensively developing cyanobacteria, which ultimately comprised nearly 60% of all the cells observed in the communities.

Glyphosate poisoning - a case report

Glyphosate is the most commonly used broad-spectrum, non-selective herbicide in the world. The toxicity is supposed to be due to uncoupling of oxidative phosphorylation and the surfactant polyoxyethylene amine (POEA)- mediated cardiotoxicity. Clinical features of this herbicide poisoning are varied, ranging from asymptomatic to even death. There is no antidote and aggressive supportive therapy is the mainstay of treatment for glyphosate poisoning. We present a 69-year-old female patient with suicidal consumption of around 500 ml of Glycel®. Initially, gastric lavage was done and intravenous fluids were given. Within two hours of presentation, the patient developed respiratory distress needing intubation, hypotension needing vasopressor support, and severe lactic acidosis. She also developed acute respiratory distress syndrome, hypokalemia, hypernatremia, and aspiration pneumonia. Our patient was critically ill with multiple poor prognostic factors, but with timely aggressive supportive management, the patient gradually recovered.

Impact of chronic exposure of rainbow trout, Oncorhynchus mykiss, to low doses of glyphosate or glyphosate-based herbicides

Glyphosate is an herbicidal active substance (AS) entering in the composition of a large diversity of pesticide products (glyphosate-based herbicides; GBH) used in modern intensive agriculture. This compound has a favorable environmental safety profile but was suspected to induce deleterious effects in aquatic organisms, with a potential effect of some associated co-formulants. This study aimed to assess the impact of direct and chronic exposure to glyphosate on the health status of rainbow trout, Oncorhynchus mykiss. A total of 36 genitors were exposed daily for 10 months to a dose of glyphosate representative of environmental concentrations (around 1 μg L-1) using the AS alone or two GBHs formulations (i.e. Roundup Innovert® and Viaglif Jardin®) and findings were compared to an unexposed control group (n=12). The effects of chemical exposure on the reproductive capacities, hemato-immunologic functions, energetic metabolism, oxidative stress and specific biomarkers of exposure were analyzed over a period of 4 months covering spawning. A limited mortality between 15% and 30% specific to the spawning occurred under all conditions. No differences were observed in reproduction parameters i.e. mean weights, relative fertility and fecundity. Red blood cell count, hematocrit index, mean corpuscular volume and white blood cell counts were similar for all the sampling dates. Significant changes were observed two months before spawning with a 70% decrease of the proportion of macrophages in trout exposed to Viaglif only and a reduction of 35% of the phagocytic activity in fish exposed to the two GBHs. Trends towards lower levels of expression of tumor necrosis factor-α (between 38% and 66%) were detected one month after the spawning for all contaminated conditions but without being statistically significant. Biomarkers of exposure, i.e. acetylcholine esterase and carbonic anhydrase activities, were not impacted and none of the chemical contaminants disturbed the oxidative stress or metabolism parameters measured. These results suggest that a 10 months exposure of rainbow trout to a concentration of 1 μg L-1 of glyphosate administered using the pure active substance or two GBHs did not significantly modify their global health including during the spawning period. The immunological disturbances observed will need to be further explored because they could have a major impact in response to infectious stress.

The impact and toxicity of glyphosate and glyphosate-based herbicides on health and immunity

Glyphosate, or N-phosphomethyl(glycine), is an organophosphorus compound and a competitive inhibitor of the shikimate pathway that allows aromatic amino acid biosynthesis in plants and microorganisms. Its utilization in broad-spectrum herbicides, such as RoundUp®, has continued to increase since 1974; glyphosate, as well as its primary metabolite aminomethylphosphonic acid, is measured in soils, water, plants, animals and food. In humans, glyphosate is detected in blood and urine, especially in exposed workers, and is excreted within a few days. It has long been regarded as harmless in animals, but growing literature has reported health risks associated with glyphosate and glyphosate-based herbicides. In 2017, the International Agency for Research on Cancer (IARC) classified glyphosate as "probably carcinogenic" in humans. However, other national agencies did not tighten their glyphosate restrictions and even prolonged authorizations of its use. There are also discrepancies between countries' authorized levels, demonstrating an absence of a clear consensus on glyphosate to date. This review details the effects of glyphosate and glyphosate-based herbicides on fish and mammal health, focusing on the immune system. Increasing evidence shows that glyphosate and glyphosate-based herbicides exhibit cytotoxic and genotoxic effects, increase oxidative stress, disrupt the estrogen pathway, impair some cerebral functions, and allegedly correlate with some cancers. Glyphosate effects on the immune system appear to alter the complement cascade, phagocytic function, and lymphocyte responses, and increase the production of pro-inflammatory cytokines in fish. In mammals, including humans, glyphosate mainly has cytotoxic and genotoxic effects, causes inflammation, and affects lymphocyte functions and the interactions between microorganisms and the immune system. Importantly, even as many outcomes are still being debated, evidence points to a need for more studies to better decipher the risks from glyphosate and better regulation of its global utilization.

Glyphosate-based herbicide formulations and reproductive toxicity in animals

The adoption of genetically engineered (GE) crops in agriculture has increased dramatically over the last few decades. Among the transgenic plants, those tolerant to the herbicide glyphosate are among the most common. Weed resistance to glyphosate-based herbicides (GBHs) has been on the rise, leading to increased herbicide applications. This, in turn, has led to increased glyphosate residues in feed. Although glyphosate has been considered to be generally safe to animal health, recent studies have shown that GBHs have potential to cause adverse effects in animal reproduction, including disruption of key regulatory enzymes in androgen synthesis, alteration of serum levels of estrogen and testosterone, damage to reproductive tissues and impairment of gametogenesis. This review emphasizes known effects of GBHs on reproductive health as well as the potential risk GBH residues pose to animal agriculture.

Cellular injury leading to oxidative stress in acute poisoning with potassium permanganate/oxalic acid, paraquat, and glyphosate surfactant herbicide

Previous studies on human acute kidney injury (AKI) following poisoning with potassium permanganate/oxalic acid (KMnO4/H2C2O4), paraquat, and glyphosate surfactant herbicide (GPSH) have shown rapid and large increases in serum creatinine (sCr) that cannot be entirely explained by direct nephrotoxicity. One plausible mechanism for a rapid increase in sCr is oxidative stress. Thus, we aimed to explore biomarkers of oxidative stress, cellular injury, and their relationship with sCr, after acute KMnO4/H2C2O4, paraquat, and GPSH poisonings. Serum biomarkers [sCr, creatine (sCn), cystatin C (sCysC)] and urinary biomarkers [cytochrome C (CytoC), 8-isoprostane (8-IsoPs)] were evaluated in 105 patients [H2C2O4/KMnO4 (N = 57), paraquat, (N = 21), GPSH (N = 27)] recruited to a multicenter cohort study. We used area under the receiver operating characteristics curve (AUC-ROC) to quantify the extent of prediction of moderate to severe AKI (acute kidney injury network stage 2/3 (AKIN2/3)). Patients with AKIN2/3 showed increased levels of CytoC. Early high CytoC predicted AKIN2/3 in poisoning with KMnO4/H2C2O4 (AUC-ROC4-8h: 0.81), paraquat (AUC-ROC4-8h: 1.00), and GPSH (AUC-ROC4-8h: 0.91). 8-Isoprostane levels were not significantly elevated. Reduced sCn and increased sCr/sCn ratios were observed for 48 h post KMnO4/H2C2O4 ingestion. Paraquat exhibited a similar pattern (N = 11), however only 3 were included in our study. Increased CytoC suggests there is mitochondrial injury coupled with energy depletion. The increased sCr within 24 h could be due to increased conversion of cellular creatine to creatinine during the process of adenosine triphosphate (ATP) generation and then efflux from cells. Later increases of sCr are more likely to represent a true decrease in kidney function.

Assessing Agricultural Toxicity in Brazil: Advances and Opportunities in the 21st Century

Agriculture in the 21st century faces multiple challenges to produce food for the growing population using ethical/sustainable and efficient methods safely for humans and the environment. Brazil today is a world leader in terms of production of food of plant origin, both for human consumption and animal feed. Agriculture and livestock raising are critical economic activities in maintaining a positive balance in its economy. As a consequence, the registration and use of pesticides in Brazil have grown at an accelerated rate. This work shows the current situation in Brazil in terms of the prevailing laws about the registration of pesticides, with a focus on the toxicological aspects related to human health. The regulatory aspects of registration of pesticides in Brazil, the mandatory testing for evaluating pesticide toxicity, adoption of the Globally Harmonized System of Classification and Labeling of Chemicals, and recent progress toward nonanimal methods to toxicity evaluation were explored in this work. In this field, Brazil has advanced and there are opportunities and challenges. There is still much to be done and investments to be made so that Brazil can definitively consolidate its conduct within the context of a Modern Regulatory Toxicology, which has entered the 21st century.

Organic diet intervention significantly reduces urinary glyphosate levels in U.S. children and adults

BACKGROUND

A growing set of studies show that an organic diet is associated with reduced levels of urinary pesticide analytes. However, with the exception of one pilot study of two individuals, diet intervention studies to date have not analyzed glyphosate, the most commonly used herbicide in the United States and globally.

OBJECTIVE

To investigate the impact of an organic diet intervention on levels of glyphosate and its main metabolite, AMPA (aminomethyl phosphonic acid), in urine collected from adults and children.

METHODS

We analyzed urine samples from four racially and geographically diverse families in the United States for five days on a completely non-organic diet and for five days on a completely organic diet (n = 16 participants and a total of 158 urine samples).

RESULTS

Mean urinary glyphosate levels for all subjects decreased 70.93% (95% CI -77.96, -61.65, p<0.010) while mean AMPA levels decreased by 76.71% (95% CI -81.54, -70.62, p < 0.010) within six days on an organic diet. Similar decreases in urinary levels of glyphosate and AMPA were observed when data for adults were examined alone, 71.59% (95% CI -82.87, -52.86, p < 0.01) and 83.53% (95% CI -88.42, -76.56, p < 0.01) and when data for children were examined alone, 70.85% (95% CI -78.52, -60.42, p < 0.01) and 69.85% (95% CI -77.56, -59.48, p < 0.01).

CONCLUSION

An organic diet was associated with significantly reduced urinary levels of glyphosate and AMPA. The reduction in glyphosate and AMPA levels was rapid, dropping to baseline within three days. This study demonstrates that diet is a primary source of glyphosate exposure and that shifting to an organic diet is an effective way to reduce body burden of glyphosate and its main metabolite, AMPA. This research adds to a growing body of literature indicating that an organic diet may reduce exposure to a range of pesticides in children and adults.

Effects of Roundup and its main component, glyphosate, upon mammalian sperm function and survival

The wide use of glyphosate-based herbicides (GBHs) has become a matter of concern due to its potential harmful effects on human health, including men fertility. This study sought to investigate, using the pig as a model, the impact of pure glyphosate and its most known commercial formulation, Roundup, on sperm function and survival. With this purpose, fresh commercial semen doses were incubated with different concentrations (0-360 µg/mL) of glyphosate (GLY; exp. 1) or Roundup, at the equivalent GLY concentration (exp. 2), at 38 °C for 3 h. Glyphosate at 360 µg/mL significantly (P < 0.05) decreased sperm motility, viability, mitochondrial activity and acrosome integrity but had no detrimental effect at lower doses. On the other hand, Roundup did significantly (P < 0.05) reduce sperm motility at ≥ 5 µg/mL GLY-equivalent concentration; mitochondrial activity at ≥ 25 µg/mL GLY-equivalent concentration; and sperm viability and acrosome integrity at ≥ 100 µg/mL GLY-equivalent concentration as early as 1 h of incubation. In a similar fashion, GLY and Roundup did not inflict any detrimental effect on sperm DNA integrity. Taken together, these data indicate that, while both glyphosate and Roundup exert a negative impact on male gametes, Roundup is more toxic than its main component, glyphosate.

Interference of goethite in the effects of glyphosate and Roundup® on ZFL cell line

Goethite (α-FeOOH) brings important perspectives in environmental remediation, as, due to its physicochemical properties, this iron oxide can adsorb a wide variety of compounds, including glyphosate. This study aimed to evaluate the effects of goethite nanoparticles (NPs), glyphosate (Gly), Roundup® (Rd), and co-exposures (Gly + NPs and Rd + NPs) on zebrafish liver cell line (ZFL). ZFL cells were exposed to NPs (1, 10, and 100 mg L-1), Gly (3.6 mg L-1), Rd (10 mg L-1), and co-exposures (Gly + NPs and Rd + NPs), or only to saline for 1, 6, and 12 h. Cell viability was assessed by Trypan blue, MTT, and neutral red assays. The generation of reactive oxygen species and total antioxidant capacity were also determined, while genotoxicity was quantified by the comet assay. Both NPs and Rd in isolation produced cytotoxic effects at 6 h and genotoxic effects at 1 and 6 h. Rd + NPs resulted in synergistic effects, intensifying the toxicity. Cells exposed to Gly did not present toxic effects and Gly + NPs resulted in the suppression of toxic effects observed for NPs. The presence of other components in Roundup® seems to favor its toxicity compared to the active ingredient. In conclusion, according to the in vitro model, the concentrations used were not safe for the ZFL lineage.

Toxicity to Rhinella arenarum tadpoles (Anura, Bufonidae) of herbicide mixtures commonly used to treat fallow containing resistant weeds: glyphosate-dicamba and glyphosate-flurochloridone

Glyphosate (GLY)-dicamba (DIC) and GLY-flurochloridone (FLC) are herbicide mixtures which are widely used for treating fallow containing glyphosate resistant weeds. The aim of this study was to evaluate the acute toxic effects and the prevailing interactions on stage 36 tadpoles of the anuran species Rhinella arenarum when exposed to equitoxic and non-equitoxic combinations of these herbicide combinations. Experiments were realized using the following combinations of commercial formulations: 48% GLY-based Credit® + 57.71% DIC-based Banvel® and 48% GLY-based Credit® + 25% FLC-based Twin Pack Gold®. GLY-DIC and GLY-FLC equitoxic mixtures were assayed mixing each constituent with an equivalent individual toxicity able to induce the same lethality effect. After 96 h of exposure, GLY-DIC and GLY-FLC equitoxic mixtures presented toxic unit 50 values (TU50 96h) of 1.74 (confidence interval: 1.58-1.92) and 1.54 (confidence interval: 1.46-1.62) respectively, indicating the presence of a weak antagonistic interaction as TU values were greater than 1. For their part, most non-equitoxic combinations of GLY-DIC and GLY-FLC tested did not significantly differ from additivity, the only exception being when DIC and FLC were fixed at 0.33 TUs, where a weak antagonism was observed. Overall, results indicate that the toxicity of both GLY-DIC and GLY-FLC mixtures to R. arenarum tadpoles vary from additive to slightly antagonistic, depending on the proportion of constituting herbicide formulations present in the mixture.

Intranasal glyphosate-based herbicide administration alters the redox balance and the cholinergic system in the mouse brain

Pesticide exposure is associated with cognitive and psychomotor disorders. Glyphosate-based herbicides (GlyBH) are among the most used agrochemicals, and inhalation of GlyBH sprays may arise from frequent aerial pulverizations. Previously, we described that intranasal (IN) administration of GlyBH in mice decreases locomotor activity, increases anxiety, and impairs recognition memory. Then, the aim of the present study was to investigate the mechanisms involved in GlyBH neurotoxicity after IN administration. Adult male CF-1 mice were exposed to GlyBH IN administration (equivalent to 50 mg/kg/day of Gly acid, 3 days a week, during 4 weeks). Total thiol content and the activity of the enzymes catalase, acetylcholinesterase and transaminases were evaluated in different brain areas. In addition, markers of the cholinergic and the nigrostriatal pathways, as well as of astrocytes were evaluated by fluorescence microscopy in coronal brain sections. The brain areas chosen for analysis were those seen to be affected in our previous study. GlyBH IN administration impaired the redox balance of the brain and modified the activities of enzymes involved in cholinergic and glutamatergic pathways. Moreover, GlyBH treatment decreased the number of cholinergic neurons in the medial septum as well as the expression of the α7-acetylcholine receptor in the hippocampus. Also, the number of astrocytes increased in the anterior olfactory nucleus of the exposed mice. Taken together, these disturbances may contribute to the neurobehavioural impairments reported previously by us after IN GlyBH administration in mice.

Glyphosate-based herbicide impairs energy metabolism and increases autophagy in C6 astroglioma cell line

Several investigators demonstrated that glyphosate formulations produce neurotoxicity associated with oxidative stress, alterations in glutamatergic system, inhibition of acetylcholinesterase activity and mitochondrial dysfunction. However, the underlying molecular mechanisms following exposure to this herbicide on astrocytes are unclear. Thus, the aim of the present study was to determine the activity of enzymes related to energy metabolism, in addition to oxidative stress parameters, mitochondrial mass, nuclear area, and autophagy in astrocytes treated with a glyphosate-based herbicide. Our results showed that 24 h exposure to a glyphosate-based herbicide decreased (1) cell viability, (2) activities of mitochondrial respiratory chain enzymes and creatine kinase (CK), (3) mitochondrial mass, and (4) nuclear area in rat astroglioma cell line (C6 cells). However, non-protein thiol (NPSH) levels were increased but catalase activity was not changed in cells exposed to the herbicide at non-cytotoxic concentrations. Low glyphosate concentrations elevated content of cells positive to autophagy-related proteins. Nuclear factor erythroid 2-related factor (Nrf2), NAD(P)H dehydrogenase [quinone] 1 (NQO1) and PTEN-induced kinase 1 (PINK1) labeling were not markedly altered in cells exposed to glyphosate at the same concentrations that an increase in NPSH levels and positive cells to autophagy were found. It is conceivable that mitochondria and CK may be glyphosate-based herbicides targets. Further, autophagy induction and NPSH increase may be mechanisms initiated to avoid oxidative stress and cell death. However, more studies are needed to clarify the role of autophagy in astrocytes exposed to the herbicide and which components of the formulation might be triggering the effects observed here.

Systematic review of comparative studies assessing the toxicity of pesticide active ingredients and their product formulations

Humans are exposed to complex chemical mixtures, such as pesticides. Although the need for the assessment of health and environmental hazards deriving from the interactions between various substances found in commercial pesticide formulations is becoming increasingly recognized, the approval of pesticide products is still mostly limited to determining the toxicity of the individual ingredients ignoring the possible combined effects in mixtures. The objective of this study was to systematically review the literature of in vitro and in vivo studies that simultaneously examine the toxicity of pesticide product formulations and their declared active ingredients to compare their toxicity to human health and to the environment. Two electronic databases were searched for studies that assessed the health effects of active pesticide ingredients and their product formulations. The literature search was performed with a combination of the following terms: "pesticide", "formulation", "commercial product", "commercial pesticide" and "health". After screening by predefined inclusion and exclusion criteria, quality and reliability assessment of eligible publications was conducted by use of the ToxRTool. Two investigators independently screened the identified publications and extracted results from eligible studies. Our search yielded 36 toxicity studies; 23 studies investigated herbicides, 15 examined insecticides and 4 focused on fungicides. Twenty-four studies reported increased toxicity of the product formulations versus their active ingredients, which, in most cases, were attributed to the presence of adjuvants in the formulations. A significant number (n = 10) of studies focused on the comparative testing of glyphosate and glyphosate-based herbicides, and six of them concluded that Roundup, the dominant product formulation of glyphosate, is more toxic than the active ingredient alone. We identified only 8 studies demonstrating reduced toxicity of product formulations in relation to the active ingredient that might be due to a potential antagonistic effect between the constituents. The results of this review demonstrate the inadequacy of current EU testing requirements for assessing the health hazards of pesticide product formulations based mainly on the evaluation of the individual ingredients and of at least one representative use and formulation. Ignoring the possible risks deriving from the interaction between the active and other ingredients of various commercial pesticide product formulations might result in the misinterpretation of its toxicological profile. At EU level efforts are currently made to address this issue. In this context, we recommend that all product formulations should be fully assessed during the authorization process.

Evaluation of apoptotic potential of glyphosate metabolites and impurities in human peripheral blood mononuclear cells (in vitro study)

Glyphosate is used for cereal, vegetable and fruit crops for reducing or inhibiting the growth of weeds as well as a desiccant for various grain crops. That is why, glyphosate has been shown to be accumulated in humans and animals through ingestion of food of both plant and animal origin. The study aimed to assessed the effect of glyphosate, its metabolites: aminomethylphosphonic acid (AMPA), methylphosphonic acid and its impurities: PMIDA, N-methylglyphosate, hydroxymethylphosphonic acid and bis(phosphonomethyl)amine on apoptosis induction in human peripheral blood mononuclear cells (PBMCs). PBMCs were exposed to the compounds studied at the concentrations ranging from 0.01 to 5 mM for 4 h. We have observed an increase in reactive oxygen species (including hydroxyl radical) and cytosolic calcium ions levels as well as reduction of transmembrane mitochondrial potential (ΔΨm) in PBMCs exposed to the compounds examined. All substances studied changed PBMCs membrane permeability, activated caspase-8, -9, -3 and caused chromatin condensation, which showed that they were capable of inducing apoptosis both via extrinsic and particularly intrinsic pathway. Generally the study demonstrated that there were no differences between apoptotic changes induced by glyphosate, its metabolites or impurities, and observed changes were provoked by high concentrations of investigated compounds.

Effects of chronic glyphosate exposure to pregnant mice on hepatic lipid metabolism in offspring

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 PPARα, 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.

Roundup-Induced AMPK/mTOR-Mediated Autophagy in Human A549 Cells

The extensive use of pesticide caused an amount of pressure on the environment and increased the potential human health risk. Glyphosate-based herbicide (GBH) is one of the most widely used pesticides based on a 5-enolpyruvylshikimate-3-phosphate synthase target, which does not exist in vertebrates. Here, we study autophagic effects of the most famous commercial GBH Roundup (RDP) on human A549 cells in vitro. Intracellular biochemical assay indicated opening of mitochondrial permeability transition pore, LC3-II conversion, up-regulation of beclin-1, down-regulation of p62, and the changes in the phosphorylation of AMPK and mTOR induced by RDP in A549 cells. Further experimental results indicated that all the effects induced by RDP were related to its adjuvant polyethoxylated tallow amine, not its herbicidal active ingredient glyphosate isopropylamine salt. All these results showed that RDP has the ability to induce AMPK/mTOR-mediated cell autophagy in human A549 cells. This study would provide a theoretical basis for understanding RDP's autophagic effects on human A549 cells and attract attention on the potential human health risks induced by the adjuvant.

Neurotoxicity of pesticides

Pesticides are unique environmental contaminants that are specifically introduced into the environment to control pests, often by killing them. Although pesticide application serves many important purposes, including protection against crop loss and against vector-borne diseases, there are significant concerns over the potential toxic effects of pesticides to non-target organisms, including humans. In many cases, the molecular target of a pesticide is shared by non-target species, leading to the potential for untoward effects. Here, we review the history of pesticide usage and the neurotoxicity of selected classes of pesticides, including insecticides, herbicides, and fungicides, to humans and experimental animals. Specific emphasis is given to linkages between exposure to pesticides and risk of neurological disease and dysfunction in humans coupled with mechanistic findings in humans and animal models. Finally, we discuss emerging techniques and strategies to improve translation from animal models to humans.

Synergistic effects of glyphosate formulation herbicide and tank-mixing adjuvants on Pardosa spiders

Glyphosate-based herbicides are the world's most consumed agrochemicals, and they are commonly used in various agroecosystems, including forests, as well as in urban zones and gardens. These herbicides are sold as formulations containing adjuvants. Other tank-mixing adjuvants (most often surfactants) are commonly added to these formulations prior to application. According to the manufacturers of agrochemicals, such tank mixes (as these are known in agronomic and horticultural practice) have modified properties and perform better than do the herbicides as used alone. The effects of these tank mixes on the environment and on beneficial arthropods are almost unknown. Therefore, we studied whether a herbicide formulation mixed with adjuvant has modified effects on one of the most common genera of ground-dwelling wolf spiders vis-à-vis the herbicide formulation and adjuvants themselves. Specifically, we studied the synergistic effect in the laboratory on the predatory activity (represented by the number of killed flies) of wolf spiders in the genus Pardosa after direct treatment using the glyphosate-based herbicide formulation Roundup klasik Pro®, Roundup klasik Pro® in a mixture with the surfactant Wetcit®, Roundup klasik Pro® in a mixture with the surfactant Agrovital®, and the surfactants alone. We found that pure surfactants as well as herbicide-and-surfactants tank mixes significantly decrease the predatory activity of Pardosa spiders in the short term even as Roundup klasik Pro® did not itself have any such effect. Our results support the hypothesis that plant protection tank mixes may have modified effect on beneficial arthropods as compared to herbicide formulations alone. Therefore, testing of pesticide tank mixes is highly important, because it is these tank mixes that are actually applied to the environment.

Effect of glyphosate on the growth, morphology, ultrastructure and metabolism of Scenedesmus vacuolatus

The effects of a commercial glyphosate formulation on the oxidative stress parameters and morphology (including the ultrastructure) of the phytoplanktonic green microalga Scenedesmus vacuolatus were evaluated. After 96 h of exposure to increasing herbicide concentrations (0, 4, 6, 8 mg L-1 active ingredient) with the addition of alkyl aryl polyglycol ether surfactant, the growth of the cultures decreased (96 h-IC50- 4.90 mg L-1) and metabolic and morphology alterations were observed. Significant increases in cellular volume (103-353%) and dry weight (105%) and a significant decrease in pigment content (41-48%) were detected. Oxidative stress parameters were significantly affected, showing an increase in the reactive oxygen species (ROS) and reduced glutathione (GSH) contents, oxidative damage to lipids and proteins and a decrease in the activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) and the detoxifying enzyme glutathione-S-transferase (GST). Cells exposed to glyphosate formulation were larger and showed an increase in vacuole size, bleaching, cell wall thickening and alteration of the stacking pattern of thylakoids. The results of this study showed the participation of oxidative stress in the mechanism of toxic action of the commercial glyphosate formulation on S. vacuolatus and the relation between the biochemical, morphological and ultrastructure alterations.