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Comparative effects of the Roundup and glyphosate on mitochondrial oxidative phosphorylation
Abstract
The potential toxicity of the herbicide Roundup and its fundamental substance (glyphosate) was tested in bioenergetic functions of isolated rat liver mitochondria. Roundup stimulates succinate-supported respiration twice, with simultaneous collapse of transmembrane electrical potential, while glyphosate used in the same concentrations does not induce any significant effect. Additionally, Roundup depresses state 3 respiration by about 40%, at 15 mM, whereas uncoupled respiration in the presence of FCCP is depressed by about 50%. Depression of uncoupled respiratory activity is mediated through partial inhibition of mitochondrial complexes II and III, but not of complex IV. The phosphorylative system was affected by both a direct and an indirect effect on the F0F1 ATPase activity. The addition of uncoupled concentrations of Roundup to Ca2+-loaded mitochondria treated with Ruthenium Red resulted in non-specific membrane permeabilization, as evidenced by mitochondrial swelling in isosmotic sucrose medium. Therefore, the uncoupling of oxidative phosphorylation is also related to the non-specific membrane permeabilization induced by Roundup. Glyphosate alone does not show any relevant effect on the mitochondrial bioenergetics, in opposition to Roundup formulation products. The differences in the toxicity observed could be either attributed to some products of Roundup or to a synergic effect of glyphosate and formulation products. Bearing in mind that mitochondria is provided with a variety of bioenergetic functions mandatory for the regulation of intracellular aerobic energy production and electrolyte homeostasis, these results question the safety of Roundup on animal health.
... Olorunsogo et al. (1979) first reported that glyphosate caused an increased oxygenation rate of isolated mitochondria and caused oxidative stress. There is some evidence that mitochondrial damage is much more prominent with GBHs rather than in pure glyphosate (Peixoto, 2005), although glyphosate did the same, just at higher concentrations. Roundup™ treatment caused loss of mitochondrial membrane potential, swelling, and non-specific membrane permeabilization at a concentration (5 mM) at which glyphosate had no effect. ...
... They conclude that GCHs cause mitochondrial inhibition and hydrogen peroxide generation. Peixoto (2005) showed that Roundup™ interferes with mitochondrial bioenergetic reactions. Changes in mitochondrial respiration and membrane energization (Δψ) were monitored as an indicator of alteration in basic mitochondrial functions. ...
... Changes in mitochondrial respiration and membrane energization (Δψ) were monitored as an indicator of alteration in basic mitochondrial functions. Glyphosate stimulates oxidative stress in the liver and kidneys by disrupting mitochondrial metabolism in rats (Peixoto, 2005;Olorunsogo, 1990). de Liz Oliveira Cavalli et al. (2013) demonstrated oxidative stress in Sertoli cells exposed to Roundup™ by increased intracellular calcium, reduced glutathione, and increased levels of thiobarbituric acid. ...
Glyphosate is the active ingredient in Roundup™, the most widely used herbicide in the world. Glyphosate targets an essential enzyme in plants that is not found in animals. However, both glyphosate and Roundup™ are rated as Group 2 A, probably human carcinogens, and also have documented effects on reproduction, acting as endocrine disruptive chemicals. We have reviewed reports of the effects of glyphosate and Roundup™ on the mammalian nervous system function. As with several other herbicides, Roundup™ 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 Roundup™ 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 Roundup™ 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 Roundup™ have significant adverse effects on the brain and behavior and increase the risk of at least some serious neurological diseases.
... The functional shift in mitochondria can lead to severe alterations of the general metabolism. In 2005 Peixoto showed that rat liver mitochondria were negatively affected by a glyphosate-based pesticide in combination with other compounds (Peixoto, 2005). ...
... Glyphosate up to 15 mM did not affect mitochondrial membrane potential, but Roundup at a concentration of 10 mM disrupted mitochondrial membrane potential in preparations from liver of Wistar rats (Peixoto, 2005). The mitochondrial mem-brane potential was lower in rat heart H9c2 cells exposed to a mixture of glyphosate and surfactant TN-20 (Kim et al., 2013). ...
... However, 0.5 mM of Roundup significantly depressed the respiratory chain and ADP/O ratio. Moreover, Roundup at concentrations up to 15 mM depressed operation of complex ІІІ and uncoupled respiration rates (Peixoto, 2005). ...
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.
... An active ingredient in Roundup is organophosphate glyphosate, N-(phosphonomethyl)glycine, in the form of its isopropylamine salt, with additional formulations containing so-called "inert" ingredients in different proportions, that are believed to be more toxic than glyphosate (Phyu et al., 2004). The mechanism of glyphosate toxicity in non-target organisms is mostly unknown, but it may cause uncoupling of oxidative phosphorylation (Peixoto, 2005). Atrazine, a triazine herbicide, that consists of a triazine ring, along with five nitrogen and one chlorine atoms, is used in the form of emulsifiable concentrate, soluble powder and granules. ...
... The molecular mechanisms of oxidative stress induction by glyphosate-based Roundup and Atrazine are well characterized. Uncoupling of mitochondrial oxidative phosphorylation may be a major effect of herbicide intoxication (Pathak et al., 2011;Peixoto, 2005). The impaired mitochondrial function caused by glyphosatebased herbicides can be related to increased ROS generation (Bailey et al., 2018;Gomes and Juneau, 2016). ...
The use of glyphosate-based Roundup and triazine herbicide Atrazine has increased markedly in last decades. Thus, it is important to evaluate toxic effects of these herbicides to non-targeted organisms such as zooplankton to understand their safety toward aquatic ecosystems. In the current study, we performed Daphnia toxicity tests based on lethality to identify LC50 that provides acute aquatic toxicity classification criteria. LC50 for Roundup exposure for 24 hours was found to be 0.022 mg/L and 48 hours - 0.0008 mg/L. Atrazine showed LC50 at concentrations of 40 mg/L and 7 mg/L for 24 and 48 hours, respectively. We demonstrated that exposure to ecologically relevant concentrations of Roundup or Atrazine decreases lipid peroxidation and protein thiol levels, however caused increase in carbonyl protein and low-molecular-weight thiols content. Moreover, the herbicide treatments caused increase of superoxide dismutase activity. Our data suggest that at very low concentrations Roundup and Atrazine disturb free radical processes in D. magna.
... Every aspect of commercial food production involves the usage of chemical products that are toxic to the mitochondria [145,149,150]. Many of the chemicals used in commercial agriculture [151][152][153][154] through the various channels of processing, perseveration and presentation, degrade thiamine and other nutrients when consumed [155]. The combination of high sugar, high toxic load and low thiamine and nutritional value in general, are likely at the root of much of the metabolic dysfunction affecting western populations. ...
... Rounding out the modern threats to thiamine status in developed countries, pervasive exposures to environmental chemicals and industrial pollutants, damage mitochondrial functioning, even at low, and what are considered, non-toxic exposures [152,[177][178][179][180] accelerating the need for thiamine and other mitochondrial nutrients. ...
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.
... In particular, energetic metabolism plays a key role in the tolerance of an organism to environmental stressors (Sokolova, 2013). Several studies indicate that glyphosate AS and/or GBHs could impact the metabolism of fish (Li et al., 2016;Soso et al., 2007;Salbego et al., 2010;Marchand et al., 2006;Peixoto, 2005;Glusczak et al., 2006Glusczak et al., , 2007Uren Webster and Santos, 2015). Particularly, Topal et al. (2015) observed a reduction of swimming performance possibly due to the dysregulation of energy metabolism in rainbow trout exposed short or long term to a GBH at concentrations of glyphosate comprised between 2.5 and 10 mg L − 1 . ...
... Craig et al. (2007) observed that Cu exposure affected this ratio in the liver of the gilthead seabream (Sparus aurata) and suggested that it could, therefore, affect normal mitochondrial biogenic processes. GBHs have been shown to generate mitochondrial dysfunction in isolated mitochondria (Peixoto, 2005), cells (Luo et al., 2017), and fish (Pereira et al., 2018) and mitochondrial impairments were reported in the brain of zebrafish (Daion rerio) sub-chronically exposed to a GBH at concentration as low as 65 μg L − 1 Pereira et al. (2018). Interestingly, mitochondrial effects and neurotoxicity did not seem to be linked to glyphosate or co-formulant concentrations. ...
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.
... Studies have demonstrated that polyethoxylated tallow amine (POEA), the most commonly identified surfactant which is seldom declared on product labels of common GBHs, increases phytotoxicity of herbicide formulations as well as exerts toxic effects on humans, animals, and microorganisms (Mann & Bidwell, 1999;Tsui & Chu, 2003;Cox & Surgan, 2006;Moore et al., 2012;Defarge et al., 2016;Tush & Meyer, 2016). As such, it is increasingly well documented that chemical mixtures in the formulations exhibit far more toxicity than glyphosate alone (Peixoto, 2005;Benachour et al., 2007;Benachour & Seralini, 2009;Gasnier et al., 2010;Frontera et al., 2011;Gasnier et al., 2011;Clair et al., 2012;Moore et al., 2012;Mesnage et al., 2014;Mesnage et al. 2015). Mass spectrometry analysis of GBHs identified both petroleum distillates (Mesenage et al., 2013) and heavy metals (Defarge et al. 2018). ...
... Similarly, treatment of zebrafish in an aquatic environment containing glyphosate at 5 ppm resulted in decreased sperm motility and decreased mitochondrial function (Lopes et al., 2014), as did in vitro treatment of human sperm cells with GBH at 1 ppm and glyphosate at 0.36 ppm (Anifandis et al., 2017(Anifandis et al., , 2018. The toxic effect of GBH on spermatozoa is likely mediated through the induction of oxidative stress and mitochondrial impairment (Peixoto, 2005;Modesto et al. 2010;Lopes et al. 2014,;Zhang et al. 2019). ...
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.
... 45 85 mg/L glifosat maruziyetinin sıçan karaciğer mitokondrisinde süksinata bağımlı solunum indeksinde azalmaya neden olduğu görülmüştür. 46 Glifosat maruziyeti sonrasında hepatositlerde solunum aktivitesinin azaldığı görülmüştür. 47 Subakut ve subkronik maruziyetin karaciğer üzerine etkisinin incelendiği bir çalışmada, sıçanlar 13 hafta boyunca 56 mg/kg ve 560 mg/kg GIBH'ye maruz bırakılmıştır. ...
... Thus, species that have a copy of the EPSPS gene may be impacted by the use of GBP. Nevertheless, even species that lack a copy of the EPSPS gene may be impacted by the herbicide through alternative non-target mechanisms43 , 44 . (ii) If the analysis of the EPSPS gene is not included in the design of the study, it is possible to get a good estimate by analyzing the 16S rRNA (bacteria) or ITS (fungi). ...
Glyphosate-based products (GBP) are the most common broad-spectrum herbicides worldwide. The target of glyphosate is the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) in the shikimate pathway, which is virtually universal in plants. The inhibition of the enzyme stops the production of three essential amino acids: phenylalanine, tyrosine, and tryptophan. EPSPS is also present in fungi and prokaryotes, such as archaea and bacteria; thus, the use of GBP may have an impact on the microbiome composition of soils, plants, herbivores, and secondary consumers. This article aims to present general guidelines to assess the effect of GBP on microbiomes from field experiments to bioinformatics analyses and provide a few testable hypotheses. Two field experiments are presented to test the GBP on non-target organisms. First, plant-associated microbes from 10 replicated control and GBP treatment plots simulating no-till cropping are sampled and analyzed. In the second experiment, samples from experimental plots fertilized by either poultry manure containing glyphosate residues or non-treated control manure were obtained. Bioinformatics analysis of EPSPS protein sequences is utilized to determine the potential sensitivity of microbes to glyphosate. The first step in estimating the effect of GBP on microbiomes is to determine their potential sensitivity to the target enzyme (EPSPS). Microbial sequences can be obtained either from public repositories or by means of PCR amplification. However, in the majority of field studies, microbiome composition has been determined based on universal DNA markers such as the 16S rRNA and the internal transcribed spacer (ITS). In these cases, sensitivity to glyphosate can only be estimated through a probabilistic analysis of EPSPS sequences using closely related species. The quantification of the potential sensitivity of organisms to glyphosate, based on the EPSPS enzyme, provides a robust approach for further experiments to study target and non-target resistant mechanisms.
... Furthermore, by investigating the interactive effects between the main ingredient and the surfactant, we also showed that glyphosate, when applied in combination with POEA (as is the case in many glyphosate-based herbicides), can further increase POEA-caused lethality. It is assumed that POEA acts synergistically with glyphosate at the mitochondrial level (Peixoto 2005). Frontera et al. (2011) indeed observed a larger decrease in oxygen consumption of Cherax quadricarinatus exposed to mixtures of POEA and glyphosate, which they attributed to enzyme inhibition, and which resulted in lowered protein levels and decreased somatic growth (Frontera et al. 2011). ...
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.
... For instance, Roundup ® caused the appearance of genotoxicity in the blood cells of alligator chicks, as well as in erythrocytes and liver cells of Corydoras paleatus fish (Poletta et al. 2009(Poletta et al. , 2011 in addition to other genotoxic effects Complimentary Contributor Copy reported in cell cultures such as mammalian bone marrow, hepatocytes, and lymphocytes (Kier and Kirkland 2013). In comparative studies between glyphosate alone and Roundup ® formulation, it was evidenced that this formulation is more toxic than glyphosate in several cell culture systems and in isolated mitochondria (Olorunsogo et al. 1979;Peixoto 2005;Benachour and Séralini 2009;. By using the alternative model Caenorhabditis elegans, it was possible to evidence abnormalities in the dopaminergic neurons, in addition to reduced fertility, inhibition of mitochondrial complex II and increase of hydrogen peroxide levels (McVey et al. 2016). ...
Glyphosate-based herbicides (GBHs) have been developed under the rationale of specifically targeting plants, since glyphosate mechanism is based on the inhibition of the shikimate pathway, present only in plants. However, this herbicide has been detected in aquatic ecosystems, wildlife and in humans and several studies have demonstrated its toxicity in different organisms. In order to better study the environmental impacts of this herbicide and its commercial formulations, animal models have been applied. Nematodes, aquatic organisms, insects and other organisms have provided important insights on the environmental impacts and important policies have been created for ecological and human health protection. This chapter reviews ecotoxicological and experimental studies on GBHs exposure and strategies that may reduce their environmental impact.
... Despite this, some proteins associated with ROS production and energy metabolism were also differentially affected by CF exposure. Glyphosate induced damage and dysfunction of the mitochondria has been widely reported in several animals (Peixoto, 2005;Lopes et al., 2018;A. G. Pereira et al., 2018;Neto da Silva et al., 2020) and combined with our findings here, highlight that the mitochondrion and its processes are particularly sensitive to glyphosate-exposure. ...
Glyphosate is one of the most widely used herbicides globally. It acts by inhibiting an enzyme in an aromatic amino 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 assessments of pesticides and their formulations, where the impact of co-formulants on non-target organisms are generally overlooked.
... Moreover, 341 adult zebrafish spermatozoa display decreased mitochondrial functionality after short-term 342 glyphosate exposure, though at concentrations exceeding those measured in the environment (5-343 10 mg/L; Lopes et al., 2014). Contrary to our findings, Peixoto et al. (2005) report that glyphosate 344 has no effect on mitochondria bioenergetics in isolated rat liver mitochondria. Together, these 345 results suggest glyphosate's mitochondrial effects are tissue and paradigm dependent, a finding 346 that would be masked by our whole animal in vivo approach. ...
Glyphosate-based herbicides (GBHs), the most recognized of which is Roundup ™ , are the most extensively used herbicides worldwide. GBHs were initially considered safe for animals since the primary target of the active ingredient, glyphosate, is only found in plants. Recent studies show that glyphosate can affect a range of animal physiologies; however, it remains poorly characterized as to whether animal GBH effects are mediated by glyphosate itself or are in response to toxic effects of the adjuvants and surfactants found in GBH formulations. Here we expose embryonic zebrafish to environmentally relevant doses of glyphosate or Roundup ™ and compare effects on two systems in the larvae: cellular bioenergetics, since glyphosate can affect mitochondrial function, and behaviour, as a systems-level readout of lasting developmental changes. We showed that exposure of embryonic zebrafish to low levels of glyphosate resulted in decreased mitochondrially-mediated basal respiration and hypoactive swimming behavior in larval stage, whereas exposure to Roundup ™ in this same treatment paradigm had the opposite effect, causing increased cellular respiration and increased locomotion. In addition, we also explored generational effects of F1 embryonic glyphosate or Roundup ™ exposure in the F2, and showed that offspring born to zebrafish exposed to low-level glyphosate or Roundup ™ during embryogenesis both exhibited reduced mitochondrially-mediated basal respiration and altered locomotion. Combined, these data show that embryonic exposure to glyphosate or the full formulation of GBHs caused differential effects on mitochondrial function and behaviours in vertebrates, with potential lasting effects on future generations. Figure 1.
Graphical abstract
Zebrafish (F1 generation) were exposed to glyphosate or Roundup ™ from zero to 48 hours, with behaviour and mitochondrial bioenergetics assessed at larval timepoints (2- and 5-dpf). Offspring of glyphosate and Roundup ™ exposed fish (F2 generation) behaviour and mitochondrial bioenergetics were assessed to the same paradigm as F1 fish at 5-dpf. Changes to core metabolic parameters and locomotion was observed in both F1 and F2 generations.
... The continuous blockage of complex III activity under high concentrations of glyphosate (≥ 75 µg l −1 ) may then result in lower oxidation of ubiquinol (UQH 2 ), with the consequent lower availability of ubiquinone (UQ) necessary for the activity of the dehydrogenases of complexes I and II, resulting in their decreased activities ( Fig. 4C and D). Different from our results, Peixoto (2005) did not observe any effect of glyphosate on the respiratory metabolism (at concentrations up to 845.354 mg l −1 ) or ETC enzyme activities (in concentrations up to 2.53 g l −1 ) of isolated rat liver mitochondria. In our study, however, the larvae and plants were exposed to glyphosate well before the evaluations, a methodology more similar to situations of environmental exposure to contaminants, for it considers alterations in the whole organism and associated effects on mitochondrial metabolism. ...
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.
Graphical abstract
... The active ingredients in Roundup are IPA-salt, polyethoxylated tallow amine (POEA) and other constituents [41]. These adjuvants can sometimes be even more toxic than glyphosate [42,43]. A thorough examination of surfactant co-formulants in glyphosate-based herbicides is urgently needed. ...
The use of synthetic molecules to achieve specific goals is steadily increasing in the environment, and these molecules adversely impact human health and ecosystem services. Considering the
adverse effects, a better understanding of how these molecules behave in the environment and their
associated risks is necessary to keep their use acceptably limited. To meet the demands of farmers
and combat weed problems, woodlands and farmlands are sprayed with agrochemicals, primarily
glyphosate-based herbicides. Farmers increasingly embrace these herbicides containing glyphosate.
Glyphosate and aminomethylphosphonic acid (AMPA), a key metabolite of glyphosate, have been
reported as toxicological concerns when they become more prevalent in the food chain. The chemical
glyphosate has been linked to various health issues in humans and other living organisms, including
endocrine disruption, reproductive issues, tumours, non-Hodgkin lymphomas, and liver, heart, and
blood problems. Therefore, the current review aims to compile data on glyphosate-based herbicide
use in the environment, potential risks to human and ecological health, and various maximum
residual limits for crops as suggested by international organizations. As a result, regulatory agencies
can advise glyphosate users on safe usage practices and synthesize herbicides more efficiently.
Keywords: glyphosate-based herbicide; AMPA; toxicological effect; ecological risk; regulations
... Owing to excess exposure to free radicals at the level of intracellular organelles, these changes can be regarded as early manifestations of apoptosis and an adaptive process to adverse environments (Wakabayashi 2002). Peixoto (2005) observed that higher sub-lethal doses of GLP depressed mitochondrial respiratory function in rat liver cells. Additionally, light microscopy showed some hepatocytes in the GLP-treated liver with dark pyknotic nuclei, which is the most characteristic feature of apoptosis (Elmore 2007). ...
... In addition, the results of various studies support the greater toxicity of commercial glyphosate formulations compared to glyphosate administered alone [147,[204][205][206]. For this reason, the results analyzed herein cannot be attributed exclusively to glyphosate, as they could have been caused by other components of the formulation or even by possible synergy between these components and glyphosate [65,[207][208][209]. ...
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.
... Thus, species that have a copy of the EPSPS gene may be impacted by the use of GBP. Nevertheless, even species that lack a copy of the EPSPS gene may be impacted by the herbicide through alternative non-target mechanisms43 , 44 . (ii) If the analysis of the EPSPS gene is not included in the design of the study, it is possible to get a good estimate by analyzing the 16S rRNA (bacteria) or ITS (fungi). ...
Glyphosate-based products (GBP) are the most common broad-spectrum herbicides worldwide. The target of glyphosate is the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) in the shikimate pathway, which is virtually universal in plants. The inhibition of the enzyme stops the production of three essential amino acids: phenylalanine, tyrosine, and tryptophan. EPSPS is also present in fungi and prokaryotes, such as archaea and bacteria; thus, the use of GBP may have an impact on the microbiome composition of soils, plants, herbivores, and secondary consumers. This article aims to present general guidelines to assess the effect of GBP on microbiomes from field experiments to bioinformatics analyses and provide a few testable hypotheses. Two field experiments are presented to test the GBP on non-target organisms. First, plant-associated microbes from 10 replicated control and GBP treatment plots simulating no-till cropping are sampled and analyzed. In the second experiment, samples from experimental plots fertilized by either poultry manure containing glyphosate residues or non-treated control manure were obtained. Bioinformatics analysis of EPSPS protein sequences is utilized to determine the potential sensitivity of microbes to glyphosate. The first step in estimating the effect of GBP on microbiomes is to determine their potential sensitivity to the target enzyme (EPSPS). Microbial sequences can be obtained either from public repositories or by means of PCR amplification. However, in the majority of field studies, microbiome composition has been determined based on universal DNA markers such as the 16S rRNA and the internal transcribed spacer (ITS). In these cases, sensitivity to glyphosate can only be estimated through a probabilistic analysis of EPSPS sequences using closely related species. The quantification of the potential sensitivity of organisms to glyphosate, based on the EPSPS enzyme, provides a robust approach for further experiments to study target and non-target resistant mechanisms.
... The syndrome bearing his name is caused by a sudden increase in intra-oesophageal pressure with negative intrathoracic pressure. This is commonly associated with retching and vomiting, but these symptoms may be absent in up to 45% of patients [3]. With a very low incidence of 3.1 per 1 000 000 people per year [4], early recognition and management are of utmost importance as the outcome is directly proportional to the time delay between onset of rupture and management [5]. ...
Glyphosate intoxication in a patient presenting with Boerhaave syndrome: A case report
... For instance, Roundup ® caused the appearance of genotoxicity in the blood cells of alligator chicks, as well as in erythrocytes and liver cells of Corydoras paleatus fish (Poletta et al. 2009(Poletta et al. , 2011 in addition to other genotoxic effects Complimentary Contributor Copy reported in cell cultures such as mammalian bone marrow, hepatocytes, and lymphocytes (Kier and Kirkland 2013). In comparative studies between glyphosate alone and Roundup ® formulation, it was evidenced that this formulation is more toxic than glyphosate in several cell culture systems and in isolated mitochondria (Olorunsogo et al. 1979;Peixoto 2005;Benachour and Séralini 2009;. By using the alternative model Caenorhabditis elegans, it was possible to evidence abnormalities in the dopaminergic neurons, in addition to reduced fertility, inhibition of mitochondrial complex II and increase of hydrogen peroxide levels (McVey et al. 2016). ...
Glyphosate [N-(phosphonomethyl)glycine] is one of the organophosphate herbicides which is most frequently used in agriculture, forestry, green public areas, and gardens for elimination of annual and perennial weeds. High efficiency in weed and pest control was achieved by using glyphosate, thus harvesting of clean and healthy final products was possible. However, extensive long-term application of glyphosate resulted in its accumulation in various environments. That accumulation poses a great concern for public health, suggesting the hazardous potential of this herbicide to various non-target organisms.
... non-essential amino acids, nucleotides, and fatty acid biosynthesis) (Chang et al., 2019;Windisch et al., 2011). Several authors have shown that GBHs were able to affect mitochondrial function in isolated mitochondria (Peixoto, 2005), cells (Luo et al., 2017), and fish (Davico et al., 2021;Lopes et al., 2014;Pereira et al., 2018). More specifically, inhibition of CCO activity and mitochondrial impairments in the brain of zebrafish were reported after chronic direct exposure to 65 μgL −1 of a GBH (Pereira et al., 2018). ...
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 μg L⁻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.
... The active ingredient, glyphosate was considered to be a nontoxic agent owing to its higher LD50 in both mice (10 g/kg) and rats (5.6 g/kg) [71 ]. This assumption is still in consistent with recent studies which proved that glyphosate alone has less toxic implications as compared to commercial formulations which are made up of mixture of active ingredients [72 ]. Limited studies are available regarding the neurotoxicity of glyphosate or formulations containing glyphosate. ...
Pesticides are described as environmental contaminants that are intentionally introduced into the environment for controlling pests. Despite the fact that pesticides play a beneficial role in augmentation of crop production by protecting crops from vector-borne disorders, there is considerable concern regarding potential toxic attributes of these pesticides. The major reason of their toxicity might be due to presence of similar targets in both pest and nontarget species including human beings. This lack of selectivity results in unwanted effects of pesticides in nontarget organisms. Majority of the pesticides, especially insecticides, have well-documented neurotoxic effects. In this chapter, we will highlight the neurotoxic effects of most commonly employed pesticides along with their possible mechanism of neurotoxicity and available treatment options. Special emphasis has been given to establish correlation between exposure of pesticides with subsequent alterations in neurological manifestations observed in humans and also mechanistic outcomes revealed by different studies conducted on animals and humans.
... Finally, the greatest fish muscle glycogen content was observed in the middle of the rice production cycle (December) while the content registered in February was similar to that quantified in November. Higher glycogen content could be the result of an inhibition of mitochondrial activity, as was observed in cell lines exposed to glyphosate-based formulations (Goulart et al., 2015;Peixoto, 2005). Even though, further research is needed to clarify the mechanisms underlying this response. ...
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.
... Owing to excess exposure to free radicals at the level of intracellular organelles, these changes can be regarded as early manifestations of apoptosis and an adaptive process to adverse environments (Wakabayashi 2002). Peixoto (2005) observed that higher sub-lethal doses of GLP depressed mitochondrial respiratory function in rat liver cells. Additionally, light microscopy showed some hepatocytes in the GLP-treated liver with dark pyknotic nuclei, which is the most characteristic feature of apoptosis (Elmore 2007). ...
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.
... The popularity of the herbicide Roundup®, the main active ingredient of which is glyphosate, has grown with the proliferation of genetically modified crops [2]. Since it is believed that the combined effects of glyphosate and the expedients in products containing it are greater than those of glyphosate alone [3], we decided to assess the impact the product Roundup ® itself has on the environment. The increasing potential exposure of ever larger segments of society to glyphosate and the development of molecular test methods have both contributed to a growing interest in this substance in the context of its biological activity and glyphosate metabolites [4]. ...
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.
... Roundup exposure studies showed alterations in mitochondrial respiratory chain complexes in the encephalon of D. rerio (Pereira et al. 2018), reduction in the number of mitochondria in hepatocytes of Cypinus carpio (Szarek et al. 2000), and a decrease in functional mitochondria in the sperm of Poecilia vivipara (Harayashiki et al. 2013), suggesting the mitochondria as target organelles of the of glyphosate-based herbicides toxicity (Pereira et al. 2018). Peixoto (2005) mentioned that glyphosate-based herbicides promote mitochondrial damage by impairing the permeability of mitochondrial membranes and altering bioenergetic activity. Moreover, since oogenesis is accompanied by an increase in mitochondrial viability, especially in the last stages of follicular maturation (Spikings et al. 2007), these mitochondrial alterations would suggest a loss of mitochondrial viability and consequently a change in oocyte maturation, as observed in the present study. ...
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.
... Both the proton gradient and the ATP levels were reduced in C. elegans (Burchfield et al. 2019), as a result of complex dysfunctions. A decrease in the activity of both complex II and III, as well as in mitochondrial membrane potentials, was observed in rat liver cells (Peixoto 2005). In human Sertoli cells, Vanlaeys et al. (2018) also observed a reduction in the complex II activity. ...
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 and/or its surfactants are believed to damage mitochondrial membranes, uncouple mitochondrial oxidative phosphorylation, and also cause lipid peroxidation (Bradberry et al., 2004;Peixoto, 2005). ...
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.
... Another example is that of glyphosate where formulations containing this active ingredient are registered in different hazard categories (Brasil, 2019b). Such divergences could be related to formulation adjuvants, which could lead a greater permeability of the product and increase of the effect, and thereby generate different biological effects and categorizations (Peixoto, 2005). When it comes to the question of human exposure, the scenario is even more uncertain, as the animal models used for assessment do not ideally simulate all the toxicity mechanisms triggered in the human organism. ...
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.
... Similarly, it has been shown that exposure to Roundup also triggers oxidative stress (El-Shenawy, 2009). The mechanism of these effects is suggested by papers demonstrating that glyphosate uncouples mitochondrial energy transduction (Olorunsogo, 1990;Olorunsogo et al., 1979), although later work comparing glyphosate and Roundup observed uncoupling effects only with Roundup (Peixoto, 2005). Similarly, oxidative damage was found to be much greater with Roundup than with glyphosate alone (Gehin et al., 2005). ...
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.
... The present data are in accordance with that were concerning in increase of SOD activity in O. limnetica. Glyphosate stress may have stimulated the generation of ROS which were reduced by the raised levels of these enzymes and helped the algal cells to tolerate the herbicide stress [64,65]. Similarly, increased activities of SOD, CAT, and APX in P. boryanum, Aulosira fertilissima, A. variabilis and Nostoc moscurum were induced under test of endosulfan [52,66]. ...
... Moreover, Roundup has been demonstrated to reduce the activity of mitochondrial succinate dehydrogenase in an immature mouse Sertoli TM4 cell line at a concentration as low as 0.001%, with heavier toxic effect than glyphosate alone 42 . By studying rat liver mitochondria, Peixoto et al. demonstrated the capacity of GBHS to alter mitochondrial bioenergetics at concentrations ≥ 5 mM glyphosate 43 . Our results are in agreement with the aforementioned studies and confirm that the compounds present in commercial herbicides may potentiate mitochondrial perturbation. ...
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.
... Additionally, honey bees that consumed pollen containing Roundup V R herbicide showed morphological alterations of mitochondria and degeneration of the rough endoplasmic reticulum in cells of the hypopharyngeal glands (Faita et al., 2018). One of the effects of Roundup V R herbicide on nontarget organisms (mammalian) involves alterations to the mitochondrial ridges, reducing the bioenergetic functions of these organelles (Peixoto, 2005). Thus, it is possible that the lower survival of bees exposed to microsporidia and also to Roundup V R results from the impairment of mitochondria and consequent production of ATP. ...
Reduction in the population of pollinators can compromise the stability of natural and agricultural ecosystems. One cause of this reduction is contact between pollinators and pesticides. More specifically, pollen and nectar which contain pesticide residues are carried into the colony, in turn, decreasing the resistance of bees to parasites. Therefore, this study aimed to evaluate the mortality and food consumption of Apis mellifera workers infected, or not, with Nosema microsporidia spores and exposed to a diet containing Roundup® at the field dose recommended by the manufacturer. Each bioassay was composed of four dietary treatments: control, Roundup®, Nosema microsporidia spores, and both Roundup® and Nosema microsporidia spores. Results of both winter and spring bioassays showed that the interaction between Roundup® and Nosema microsporidia significantly reduced survival rate and increased food consumption of the bees. Therefore, it can be concluded that the large amounts of glyphosate-based herbicides employed on extensive monocultures can, under current agroecosystem conditions, compromise the survival of A. mellifera colonies.
... The liver and pancreas of mice were affected, as highlighted by disturbances in sub-nuclear structure (Malatesta et al., 2008). Toxic effect of very low dilutions of round up on apoptosis, mitochondrial function, and cell membrane degradation inducing necrosis of hepatocytes, and other cell lines (Benachour and Seralini, 2009;Benachour et al., 2007;Gasnier et al., 2010;Peixoto, 2005). Glyphosate consumption in water caused hepatic failure (Séralini et al., 2012) f The present results revealed that the inflammatory infiltration found in the kidney in treated animals may be due to the effect of the glyphosate. ...
Mitochondria perform several biological functions in living organisms, such as ATP production; calcium, copper, and iron homeostasis; pyrimidine and steroid synthesis; thermogenesis; and calcium signaling. Xenobiotics have high affinity for compounds and present different potentials. When xenobiotics are present in the mitochondrial membrane, they lead to various disturbances and cause the organelle to collapse, altering the electron transport chain and resulting in loss of energy production and even cell death. Due to their structural and functional characteristics and because they can act as biosensors, mitochondria are important targets for assessing the toxicity of xenobiotics. Many methods, including colorimetry and fluorimetry, among others, can be used to clarify the mechanisms that induce mitochondrial damage and will be addressed throughout this chapter.
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.
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.
The use of agrochemicals has increased in recent years, following the growth of agricultural productions, 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 environment, especially the aquatic, by processes such as leaching and drifts. Glyphosate [N-(phosphonomethyl) glycine] is the most commonly used herbicide in agriculture worldwide. Studies have shown that this contaminant is toxic to a variety of fish species at the concentrations of environmental relevance. Pure glyphosate and its formulas can compromise biochemical, physiological, endocrine, and behavioral pathways. The behavior patterns of fish are a sensitive tool for risk assessment. Changes in behavior such as food search, escape from predators, and the courtship for reproduction can compromise the survival of species and even communities. In this sense, this review summarizes and discusses, for the first time, the toxic effects of glyphosate and its formulations on the behavior of fish in different life stages. Additionally, we associated the behavioral disturbances with other effects of glyphosate such as on energy imbalance, stress responses, AChE inhibition, and endocrine disruptors, evidence and described in the literature, were associated.
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. Roundup caused developmental delay and increased larvae mortality in Drosophila melanogaster. Roundup treatment during development reduced hemolymph glucose and glycogen levels in adult flies of both sexes at the highest concentration tested. Chronic exposure of adult flies decreased appetite, body weight, and shortened lifespan suggesting that high concentrations of Roundup are deleterious to both larvae and adults, resulting in a shift of the metabolism and antioxidant defense system in D. melanogaster.
Le glyphosate, substance active herbicide (SA) la plus utilisée dans le monde, est omniprésent dans les eaux de surface. L’évaluation de son écotoxicité et de celle des herbicides commerciaux à base de glyphosate (GBHs) est complexe et controversée. Le glyphosate et ses co-formulants peuvent être toxiques pour les poissons et leurs interactions ainsi que la transmission verticale de cette toxicité sont relativement peu étudiées. La toxicité directe et générationnelle d’une dose environnementale de glyphosate a été évaluée sur plusieurs générations de truites arc-en-ciel exposées chroniquement à la SA et à deux GBHs. L’état de santé des poissons a été déterminé via la mesure de paramètres biométriques, comportementaux et reproducteurs. L’immunité a été appréhendée lors d’infections virales expérimentales. Le métabolisme énergétique et le système antioxydant ont été suivis avec des marqueurs biochimiques. L’exposition directe aux contaminants n’a pas impacté la physiologie et la reproduction de la génération F0. Des perturbations du développement embryo-larvaire des descendances F1 et F2 ont été induites par les expositions directes, inter et transgénérationnelles ; avec un effet suggéré de la réexposition aux composés parentaux. Les modifications observées chez les stades précoces n’ont pas été détectées chez les truites juvéniles, bien que leur susceptibilité virale ait été affectée. La comparaison des effets du glyphosate et des GBHs semble montrer un rôle des co-formulants dans la modulation de la toxicité de la SA. Cependant, d’autres études sont nécessaires pour approfondir la compréhension liée aux mécanismes complexes de transmission de la toxicité du glyphosate.
Nowadays, glyphosate, and its commercial formulation (Roundup 41% SL, Bayer AG, Leverkusen, Germania), is the most widely used broad-spectrum herbicide in industrial agriculture for weed control. The massive use of this substance also affects aquatic ecosystems and water organisms around the world. The potential toxic effects of glyphosate on aquatic specimens should worry us. Indeed, animals such as grass carp are part of the human food chain, so exposure to glyphosate may cause environmental damage and harm human health. In this study, the effect of acute 96h exposure of the commercial formulation of glyphosate (Roundup) on blood biochemical indices of grass carp ( Ctenopharhyngoden idella ) was evaluated. Three different concentrations of glyphosate were chosen for exposure to three groups of 21 animals each. The lowest was 50mg.L ⁻¹ , the intermediate concentration was 100mg.L ⁻¹ , and the highest concentration was 150mg.L ⁻¹ . The toxicity of the pollutant was tested using lethal concentrations and determining the LC50 (lethal concentrations for 50% of fish). Histopathological damage to the gills and liver was also evaluated, as well as the survival rate of the fish. Results showed severe gill and liver damage, with necrosis, leukocyte infiltration, hyperplasia and hypertrophy, in the group exposed to the highest concentration of glyphosate (150 mg.L ⁻¹ ). Many biochemical changes were also observed, confirming the toxicity hypothesized at the start of the study.
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 1h 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.
Persistent organic pollutants (POPs) are organic compounds that are nondegradable by chemical, biological, and photolytic processes. Because of their continuous bioaccumulation in the environment, they impart drastic effects on human health. The hazardous effects of POPs are so impactful that a special “Stockholm Convention on POPs” was organized in 2001 to highlight the emerging problem. As an early measure, the convention banned or restricted the production of some 12 pollutants worldwide. Besides the endocrinological, gastroenterological, and dermatological complications, these POPs also exert their harmful effects on the nervous system. Clinical signs of Parkinson’s disease, Alzheimer’s disease, stroke, epileptic seizures, multiple sclerosis, dementia, and attention deficit hyperactive syndrome are observed in POPs exposed people. Moreover, in vitro and in vivo studies reveal that organochloride and organophosphate both can cross the blood–brain barrier and damage the dopaminergic, cholinergic, and serotonergic neurons. Additionally, these pollutants can increase or decrease the levels of neurotransmitters and exert oxidative damage to neuronal cells. Certain POPs can activate neuroinflammatory pathways by disrupting expressional levels of proinflammatory and anti-inflammatory cytokines. Presence of a few selective studies with limitations and lack of conclusive outcomes, the exclusive epidemiological studies focusing on the effect of POPs on neurological disorders are lacking in modern-day literature. There is no antidote available in the treatment of organochloride exposure as yet, however for organophosphate exposure, pralidoxime is used. On chronic exposure of POPs, symptomatic treatment is recommended. Such endeavors should be encouraged that highlight the ways of controlling the exposure of pollutants.
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental toxic chemicals which include more than 100 chemicals, mainly produced as a result of improper combustion of organic substances like wood, coal, petrol and oil. These pollutants are released into the environment due to various activities including open air burning, natural losses, leakage of various chemicals, accidental fire and many more. The most common sources of PAHs production are house hold heating systems, plants using coal for gasification and liquefaction, various industries and factories manufacturing different livelihood products, petroleum refineries and automobile exhaust. PAHs metabolites (especially 1-OHP) in urine, and PAH–DNA adducts with DNA, RNA and proteins in WBCs and other tissues, which are part of PAH toxic mechanisms, are used to measure PAH exposure in humans. Despite of different biological barriers such as placenta and blood–brain barrier, brain still has unique susceptibility to environmental risk factors during its developmental period compared with the mature nervous system. Benzo(a)pyrene is one of the most toxic PAHs known which is often used as an indicator of PAH exposure in various epidemiological studies. PAHs combat and interfere with the functions of cellular membrane and its enzyme systems to cause cytotoxicity. Chronic exposure to even low concentration of these chemicals cause ever-lasting damages including infertility, cancer and neurotoxicity to humans as well as wild life. Epigenetic effects, oxidative stress and endocrine disruptions are some of the mechanisms investigated for PAHs neurotoxicity. As brain is the most vulnerable organ to oxidative damage due to low oxygen level which may cause alteration in gene expression, impairment in cellular signaling, membrane integrity disruption, altered neurotransmission and ultimately neuronal cell death. The oxidative stress (due to ROS) produced in the CNS causes reduction in the antioxidant enzymes activities which are crucial for the behavioral effects induced by PAHs especially B(a)P. Adsorption, volatilization, photolysis and chemical degradation are some of the important processes in the removal of PAHs from both the atmosphere and environment. Among these, microbial degradation is considered to be the major PAHs degradation process.
A pollutant with the newly established toxic mode is categorized as an emerging environmental contaminant; many point and non-point sources introduce these contaminants in the environment. Volatile organic compounds (VOCs) are the compounds having a low boiling point, variable lipophilicity and volatility, and are being produced from anthropogenic activities and natural sources. With BTEX (Benzene, toluene, ethylbenzene, and xylene) compounds being most abundant (up to 60%), VOCs are used as a reference for the evaluation of VOC exposure and levels in the environment. VOCs may cause behavioral, neurological, dermatological, and respiratory symptoms in humans as evident from experimental and epidemiological data. Humans are exposed to VOCs through skin, GIT, and lungs. Due to the high lipophilicity of VOCs, they can cross biological membranes and the blood–brain barrier (BBB) and thus resulting in numerous neuropsychiatric disorders, comprising of diminished impulsive control, changes in the motor and cognitive functions, hallucinations, headache, dizziness, and dementia. The mechanism of neurotoxicity of single VOC has not been elucidated completely because VOCs are always present as a mixture, but the possible reason may be the oxidative stress and changes in the neurotransmitters and ion channels functions. Several epidemiological and experimental studies (in vivo and in vitro) have been conducted for assessment of neurotoxic mechanism, risk of acute and chronic exposure, and neurobehavioral changes. BTEX compounds are the most toxic environmental pollutants and cause several neuropsychiatric changes including dementia, headache, nausea, malaise, impairment in learning, and memory; toluene is also associated with leukoencephalopathy, fetal solvent syndrome, and sick building syndrome and targets white matter of the brain. Other VOCs having a higher potential of neurotoxicity include solvents containing chlorine, such as trichloroethylene (TCE), perchloroethylene (PERC) and dichloromethylene, formaldehyde, n-hexane and acetone. VOCs’ occupational exposure level in workers is monitored through the measurement of biomarkers; a recent technique for assessment of environmental agents’ exposure is the measurement of micro-RNAs in plasma/serum. Health risks from VOCs are inevitable due to their ubiquitous nature, and measures should be adopted especially in workplaces, urban and industrial areas to keep the level of toxic VOCs below the operational exposure limit (OELs).
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.
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.
Keywords: Fructose; Glyphosate (ForceUp®); Oxidative Stress; Type 2 Diabetes; Wistar rats.
Sepiolite clay mineral was functionalized with (3-chloropropyl)triethoxysilane (ClPTES) or 3-[tri(ethoxy/methoxy)silyl] propylurea (TEMSPU) alkoxides and tested as adsorbent for herbicide glyphosate and also of caffeine, two pollutants with very different chemical composition. The materials obtained were characterized by X-ray diffractometry, infrared spectroscopy, thermal analysis, scanning electron microscopy and nitrogen adsorption at − 196 °C, and submitted to toxicity and desorption tests. Silane functional groups blocked sepiolite active positions, and adsorption occurred within the zeolitic channels and on the surface of the functionalized solids. Caffeine and glyphosate effectively interacted with urea groups from grafted alkoxide, which could lower the mobility of the adsorbed contaminants. Glyphosate adsorbed on functionalized sepiolite derivatives showed low toxicity.
This paper reports an investigation on the relationship between the proton electrochemical gradient (delta mu H+) and the cyclosporin A-sensitive permeability transition pore (PTP) in rat liver mitochondria. Using the SH group cross-linker phenylarsine oxide as the inducer, we show that both matrix pH and the membrane potential can modulate the process of PTP induction independently of Ca2+. We find that membrane depolarization induces the PTP per se when pHi is above 7.0, while at acidic matrix pH values PTP induction is effectively prevented. Since Ca2+ uptake leads to major modifications of the delta mu H+ (i.e. matrix alkalinization and membrane depolarization), we have explored the possibility that the Ca(2+)-induced changes of the delta mu H+ may contribute to PTP induction by Ca2+. Our data in mitochondria treated with Ca2+ plus N-ethylmaleimide and Ca2+ plus phosphate show that membrane depolarization is a powerful inducer of the PTP. Taken together, our observations indicate that the PTP can be controlled directly by the delta mu H+ both in the absence and presence of Ca2+, and suggest that a collapse of the membrane potential may be the cause rather than the consequence of PTP induction under many experimental conditions. Thus, many inducers may converge on dissipation of the membrane potential component of the delta mu H+ by a variety of mechanisms.
Increased risk for non-Hodgkin's lymphoma (NHL) following exposure to certain pesticides has previously been reported. To further elucidate the importance of phenoxyacetic acids and other pesticides in the etiology of NHL a pooled analysis was performed on two case-control studies, one on NHL and another on hairy cell leukemia (HCL), a rare subtype of NHL. The studies were population based with cases identified from cancer registry and controls from population registry. Data assessment was ascertained by questionnaires supplemented over the telephone by specially trained interviewers. The pooled analysis of NHL and HCL was based on 515 cases and 1141 controls. Increased risks in univariate analysis were found for subjects exposed to herbicides (OR 1.75, CI 95% 1.26-2.42), insecticides (OR 1.43, CI 95% 1.08-1.87), fungicides (OR 3.11, CI 95% 1.56-6.27) and impregnating agents (OR 1.48, CI 95% 1.11-1.96). Among herbicides, significant associations were found for glyphosate (OR 3.04, CI 95% 1.08-8.52) and 4-chloro-2-methyl phenoxyacetic acid (MCPA) (OR 2.62, CI 95% 1.40-4.88). For several categories of pesticides the highest risk was found for exposure during the latest decades before diagnosis. However, in multivariate analyses the only significantly increased risk was for a heterogeneous category of other herbicides than above.
An increased rate of non-Hodgkin's lymphoma (NHL) has been repeatedly observed among farmers, but identification of specific exposures that explain this observation has proven difficult.
During the 1980s, the National Cancer Institute conducted three case-control studies of NHL in the midwestern United States. These pooled data were used to examine pesticide exposures in farming as risk factors for NHL in men. The large sample size (n = 3417) allowed analysis of 47 pesticides simultaneously, controlling for potential confounding by other pesticides in the model, and adjusting the estimates based on a prespecified variance to make them more stable.
Reported use of several individual pesticides was associated with increased NHL incidence, including organophosphate insecticides coumaphos, diazinon, and fonofos, insecticides chlordane, dieldrin, and copper acetoarsenite, and herbicides atrazine, glyphosate, and sodium chlorate. A subanalysis of these "potentially carcinogenic" pesticides suggested a positive trend of risk with exposure to increasing numbers.
Consideration of multiple exposures is important in accurately estimating specific effects and in evaluating realistic exposure scenarios.
The effects of dicamba, a widely used broad-leaf herbicide, on rat liver mitochondrial bioenergetic activities were examined. The results obtained for state 4 respiration indicate not only an uncoupling effect, the result of an increase on the permeability of inner mitochondria membrane to protons, but also a strong inhibitory effect on the redox complexes. State 3 and respiration uncoupled by FCCP (carbonylcyanide p-trifluoromethoxyphenylhydrazone) were inhibited to approximately the same extent, i.e. by about 70%. Depression of respiratory activity is essentially mediated through partial inhibition of mitochondrial complexes II and III. ATPase activity was much less depressed by dicamba than ATP synthase activity. Therefore, a considerable part of the inhibition observed on ATP synthase is the result of an inhibition on the redox complexes. The loss of phosphorylation capacity, induced by dicamba, was in the last analysis not only the result of a direct effect of dicamba on the enzymatic complex (F(0)-F(1) ATPase) but also the result of a deleterious effect on the integrity of the mitochondrial membrane, which can promote an inhibition of the respiratory complexes and an increase of the proton permeability of the inner membrane.
Glyphosate [N-(phosphonomethyl)glycine]herbicide can be topically applied twice at rates as high as 0.84 kg a.e. (acid-equivalent) ha(-1) to glyphosate-resistant cotton (Gossypium hirsutum L.) cultivars until the fourth true leaf stage, with the requirement of at least 10 d and two nodes of growth between applications. But, such cultivars are not reproductively resistant to glyphosate applied topically or imprecisely directed after the four-leaf stage because glyphosate can curtail pollen development and ovule fertilization, which potentially reduces yield. Extending glyphosate resistance past the four-leaf stage would provide growers with additional weed management options. Our objective was to test under field conditions glyphosate resistance of cotton germplasm transformed with gene constructs previously shown to impart extended glyphosate resistance in the greenhouse. Four or six transgenic cotton lines containing one of several constructs conferring extended glyphosate resistance, plus the current glyphosate-resistant control ('Coker 312'-1445), were tested at nine U.S. locations in 2001. Within locations, treatment designs consisted of cross-classified arrangements of transgenic lines and glyphosate rates [0, 1.68, and 2.52 kg a.e. ha(-1)]. Treated plots received glyphosate over-the-top of cotton at four growth stages (3-, 6-, 10-, and 14-leaf crop stages). Compared with Coker 312-1445, extended glyphosate resistance was expressed as higher yields when glyphosate was applied topically at the four growth stages. Mature plant mapping confirmed extended glyphosate resistance of the new transgenic cotton through similar fruit distribution and weight with or without glyphosate treatment. The capability to apply glyphosate topically to cotton later in crop development will facilitate weed management and could reduce dependence on directed herbicides.
During the past years a comprehensive model for the regulation of mitochondrial oxidative phosphorylation has been developed. The model can account for the observed relationship among the cellular energy supply ([ATP][ADP][Pi]) the intramitochondrial reducing power ([NAD+][NADH]) and the cellular respiratory rate.
G rowers have overwhelmingly adopted glyphosate- resistant (Roundup Ready, Monsanto Co., Ches- Glyphosate (N-(phosphonomethyl)glycine) herbicide can be topi- terfield, MO) cotton cultivars since introduction in 1997. cally applied twice at rates as high as 0.84 kg a.e. (acid-equivalent) In 2002, about 72% of the U.S. hectarage was planted to ha 1 to glyphosate-resistant cotton (Gossypium hirsutum L.) cultivars until the fourth true leaf stage, with the requirement of at least 10 d cultivars containing the Monsanto glyphosate resistance and two nodes of growth between applications. But, such cultivars gene alone, or combined with Monsanto's Bollgard gene are not reproductively resistant to glyphosate applied topically or (derived from Bacillus thuringiensis var. kurstaki) con- imprecisely directed after the four-leaf stage because glyphosate can ferring protection from certain lepidopteran pest insects curtail pollen development and ovule fertilization, which potentially (Perlak et al., 1991; USDA-AMS, 2002). The popularity reduces yield. Extending glyphosate resistance past the four-leaf stage of glyphosate-resistant cotton cultivars reflects the broad- would provide growers with additional weed management options. spectrum weed control possible with glyphosate, plus Our objective was to test under field conditions glyphosate resistance capability to farm cotton on more hectares compared of cotton germplasm transformed with gene constructs previously with traditional weed management approaches (Cul- shown to impart extended glyphosate resistance in the greenhouse. pepper and York, 1998; York, 1997). Four or six transgenic cotton lines containing one of several constructs The limitation of the current cotton glyphosate resis- conferring extended glyphosate resistance, plus the current glypho-
Field studies were conducted in Alabama in 1998 and 1999 to evaluate fomesafen preemergence (PRE) in glyphosate-resistant cotton. Fomesafen (0.3 and 0.4 kg ai/ha), fluometuron (1.4 kg ai/ha), and pyrithiobac (0.05 kg ai/ha) were applied alone or in tank mixtures. Glyphosate (0.4 kg ae/ha) was applied postemergence over-the-top (POT) and postemergence directed (PD). Regardless of PRE treatment, POT followed by (fb) PD applications of glyphosate were necessary for greater than 82% sicklepod control at midseason. In the absence of glyphosate, fomesafen, and fomesafen-containing tank mixtures controlled common cocklebur and Ipomoea species 77 and 72%, respectively, 14 d after PD application. However, two applications of glyphosate were needed for .>94% season-long control of common cocklebur and Ipomoea species because of continued germination throughout the growing season. Postemergence applications of glyphosate added a 1,000 kg/ha seed cotton yield increase to all PRE treatments at both locations. Common cocklebur, Ipomoea species, and sicklepod control was not significantly increased by the addition of fomesafen PRE tank mixtures fb glyphosate postemergence as compared with glyphosate postemergence only.
This chapter describes the preparation and properties of succinie–cytochrome c reductase (complex II - III). Assays of enzymatic activity are carried out at 38° in a Beckman Model DU spectrophotometer, equipped with a photomultiplier. The final reaction mixture contains ten micromoles phosphate buffer (0.10 ml); one micromole NaN3 (0.01 ml); 0.2 micromole EDTA (0.02 ml); five mg BSA (0.05 ml); 10 micromoles potassium succinate, pH 7.0 (0.10 ml); and water to a volume of 0.9 ml. The enzyme preparation to be assayed is diluted to a concentration of 100-200 μg protein per milliliter in a solution of 0.88 M sucrose 0.005 M in succinatc. The enzyme-catalyzed reduction of cytochrome c by succinate proceeds at a linear rate under standard conditions over the first minute. Then specific activity is calculated. The resulting increase in absorbancy at 550 mμ is followed during this linear phase. In the method of preparation as described in the chapter, beef heart mitochondria are isolated in 0.25 M sucrose and are frozen at –40° for a period of 1-7 days. The yield and increase of activity during the purification of the succinic-cytochrome c reductase is also illustrated.
Acid dissociation constants have been measured for arsenic acid (H3AsO4), methylarsonic acid (CH3AsO3H2; MAA), dimethylarsinic acid [(CH3)2AsO2H; cacodylic acid], and N-(phosphonomethyl)glycine (HO2CCH2NHCH2PO3H2; glyphosate). A recently devised mathematical technique for pK and end point determinations which corrects for strong acid or base impurities was modified and used to analyze automatic titrator titration curves and correct pK values to zero ionic strength. Thermodynamic pK values = -log (aHaA/aAH) at 25°C are: H3AsO4, pK2 = 7.089 ± 0.01; MAA, pK1 = 4.114 ± 0.01, pK2 = 9.148 ± 0.01; cacodylic acid, pK1 = 6.288 ± 0.01; glyphosate, pK1 = 2.32 ± 0.03, pK2 = 5.86 ± 0.03, pK3 = 10.86 ± 0.03.
The penetration and effects of the sodium salt of glyphosate,N-(phosphonomethyl) glycine, in isolated potato tuber mitochondria were investigated. The penetration studyrequired the measurement of the volume of mitochondrial water space and this measurement was repeatedlycarried out using [14C]dextran giving a value of 3.53 μl mg−1 protein. After a 15 minute incubation periodwith medium containing 1 μM or 1 mM glyphosate, without respiratory substrate, almost no product was found in themembrane pellet, after disruption of the organelles in distilled water. In contrast, glyphosate was found in themitochondrial water in a range of concentrations close to the external medium concentration. These results show that, at leastthe diffusion equilibrium between the medium, the intermembrane space and the matrix area was readily reached forglyphosate. The greater part of the product penetrated during the first five minutes of the incubation period.The glyphosate content, in mitochondria operating at 25°, was not changed by adding either substrate. (state IV), orsubstrate + ADP (state III). The probability of an active glyphosate transport by the mitochondrial inner membrane wastherefore very unlikely. Glyphosate, at a concentration as high as 50 mM, was unable to change therespiratory activities of isolated potato tuber mitochondria(oxygen consumption rate with different substrates, ADP/O, respiratorycontrol values, etc.).
IntroductionAssay of Succinate Dehydrogenase and Succinoxidase in Animal TissuesApplication of Succinate Dehydrogenase Assays to Yeast, Bacteria, and Higher PlansNADH Dehydrogenase and NADH Oxidase AssaysAssay of Choline DehydrogenaseAssay of Mitochondrial α-Glycerophosphate Dehydrogenase
Public concern about the degradation of surface and groundwater quality has stimulated rigorous efforts to develop reliable biological methods for quantifying aquatic toxicity. Most methods have focused on the use of fish or aquatic invertebrates toassess risk to humans and other species posed by chemical pollutants in water. However, most of these tests are too expensive and timeconsuming to form the basis for affordable water quality surveillance programs on an extensive scale. For example, acute fish tests, which are the most commonly used, cost approximately $700 per assay and require 48 to 96 h to determine median lethal concentrations (LCbo) of test substances or water samples. Requirements for specialized laboratories, cultivation of test organisms, variations in response related to species difference, and cumbersome statistical procedures are among other important problems that diminish the utility of acute toxicity tests using fish. Only minor improvements in cost, time, and response factors are afforded by acute toxicity tests with aquatic invertebrates such as those based on mortality of the water flea (Daphnia magna). Consequently, there is a pressing need to develop rapid and inexpensive, yet reliable and sensitive tests to monitor microcontamlnant trends in water quality and to determine toxicity of complex effluents discharged into aquatic systems. Use of rapid in v~tro bloassays for monitoring water quality and determining toxicity of effluents or chemical substances is a recent development. Tests based on bacterial responses are at the forefront of this new category of bioassay. Dutka and Kwan (1981) compared four different microbial toxicity testing systems and found the Beckman Microtox TM bloassay, based on reducing light emission from Photobacterium phosphoreum due to the presence of toxins (Bullch 1979) to be fastest and most sensitive. However, this appraisal and subsequent studies have suggested that the utility of the 5-mln Microtox" test may be compromised by poor sensitivity and erratic reproducibility (Blondin et al. 1985) and by the occurrence of falsely negative results from environmental samples (Qureshl et al. 1982). Nevertheless, studies with bacterial test systems have established the feasibility of designing rapid and inexpensive in vitro bioassays that could be
The effects of exposure of human erythrocytes to different concentrations of Roundup Ultra 360 SL and its active compound glyphosate were studied. We studied hemolysis after 1, 5, and 24 h incubation; lipid peroxidation, hemoglobin oxidation, the level of reduced glutathione, and the activity of catalase after 1 h. Human erythrocytes were incubated with 100–1500 ppm (100 μg/ml erythrocytes at 5% hematocrite) Roundup Ultra 360 SL and glyphosate. We have found that after 1 h of incubation only Roundup Ultra 360 SL increased the level of methemoglobin, products of lipid peroxidation at 500 ppm and hemolysis at 1500 ppm [Curr. Top. Biophys. 26 (2002) 245], while its active compound glyphosate increased the level of methemoglobin and the level of lipid peroxidation at much higher dose—1000 ppm. At the same time hemolysis was observed to only at the highest dose of glyphosate (1500 ppm) and the longest time of incubation (24 h). Both Roundup Ultra 360 SL and glyphosate did not cause statistically significant changes in the level of GSH, but increased the activity of catalase. Roundup Ultra 360 SL provokes more changes in the function of erythrocytes than its active substance glyphosate, which is probably a result of the properties of additives. Taking into account the limited accumulation of Roundup Ultra 360 SL and glyphosate in the organism as well as the fact that the threshold doses which caused changes in erythrocytes for Roundup Ultra 360 SL were only 500 and 1000 ppm for glyphosate, one may conclude that this pesticide is safe towards human erythrocytes.
This chapter discusses the preparation and activity of native and chemically modified cytochromes c. Cytochrome c is extracted from ground and homogenized tissue with a dilute solution of aluminum sulfate at pH 4.5, the trivalent cations effectively displacing the protein even at low ionic strength. Aluminum ions are precipitated as the hydroxide at slightly alkaline pH, and each is replaced in solution by three monovalent ammonium ions. The cytochrome c is purified by (NH4)2SO4 fractionation and cation-exchange chromatography. This method of extraction is suited to vertebrate and invertebrate tissues, but for plant materials, protists, or fungi, special cytolysis procedures are often required before use of a similar scheme. Although both these aspects of cytochrome c function are interesting, it seems that the biologically significant evolutionary variations of cytochrome c structure predominantly affect the mechanics of protein–protein interaction with its physiological oxidants and reductants, rather than the mechanism of electron transfer.
The results presented reveal that glyphosate enhanced the rate of oxygen consumption by the mitochondria isolated from the livers of rats 5 hr after a single intraperitoneal dosing with glyphosate when the reaction medium was deficient in phosphate acceptor. The respiratory control ratios of these mitochondria were also reduced. At 60 mg/kg this parameter was reduced by at least 40 percent. The partial reactions of oxidative phosphorylation are presumed to be reflections at the reversibility and multistep nature of the coupling mechanisms. An important partial reaction of oxidative phosphorylation is adenosine triphosphatase (ATPase) activity which is characteristically stimulated by dinitrophnol and other uncoupling agents. Because of the enhancement effect of glyphosate on ADP-less respiration and its inhibitory effects on ADP-stimulated respiration in the mitochondria obtained from the livers of glyphosate-poisoned rats, the effect of the herbicide on ATPase activity was investigated. The results presented reveal that ATPase activity was enhanced in the livers of the animals treated with the herbicide. The activities of the dehydrogenases of the common two- or three- site substrates were also slightly enhanced in the hepatic mitochondria of the glyphosate-poisoned animals. These findings suggest that uncoupling of mitochondrial oxidative phosphorylation may be a major lesion in glyphosate intoxication.
The membrane potential of mitochondria was estimated from the accumulation of tetraphenyl phosphonium (TPP+), which was determined with the TPP+-selective electrode developed in the present study. The preparation and some operational parameters of the electrode were described. The kinetics for uptake by mitochondria of TPP+ and DDA+ (dibenzyldimethyl ammonium) were analyzed, and it was found that TPP+ permeated the mitochondrial membrane about 15 times faster than DDA+. The final amounts of accumulation of TPP+ and DDA+ by mitochondria were approximately equal. For the state-4 mitochondria, the membrane potential was about 180 mV (interior negative). Simultaneous measurements of TPP+-uptake and oxygen consumption showed that the transition between states 3 and 4 was detectable by use of the TPP+-electrode. After the TPP+-electrode showed that state-4 was reached, the extra-mitochondrial phosphorylation potential was measured. The difference in pH across the membrane was measured from the distribution of permeant anion, acetate, so as to calculate the proton electrochemical potential. The ratio of extra-mitochondrial phosphorylation potential to proton electro-chemical potential, n was close to 3. This value of n was also found to be 3 when ATP was hydrolyzed under the condition that the respiratory chain was arrested. The implication that n = 3 was discussed.
New spectrophotometric bioassay procedures have been developed for evaluating chemical toxicity, using electron transport particles isolated from bovine heart mitochondria, based on the ability of many toxic chemicals to interfere with the integrated function of electron transport enzymes. The sensitivity of the mitochondrial assay is compared to published sensitivities of other in vivo and in vitro toxicity testing methods. Regression analysis of logarithmically transformed toxicity values for 42 chemicals, including 8 pesticides, 5 drugs, 6 metals, 8 alcohols, 5 respiratory inhibitors, 4 phenols, and 2 phthalates, indicates excellent correlation between the sensitivity of the new assays and the sensitivity of mammalian cytotoxicity studies (r2 = 0.86). Data from aquatic exposure toxicity tests conducted in fish are also highly correlated with the mitochondrial assay results (r2 = 0.79). However, correlation of data from these methods with median lethal dose studies conducted in rats is not as good because of the inability of in vitro and aquatic exposure analyses to account for the gastrointestinal absorption, hepatic metabolism, and excretion processes which modify toxic responses following oral administration.
Three bioassays which use submitochondrial electron transport particles (ETP) to evaluate chemical toxicity have been developed. These tests were initially designed for use in water quality monitoring. However, they are also valuable for assessing the toxicity of new and existing chemicals. The current investigation studies the ability of these procedures to predict in vivo tissue concentrations associated with clinical illness in man. To examine this potential, data obtained using the mitochondrial tests were compared to chemical concentrations measured in human blood samples obtained during the acute stage of chemical-induced illness. Twenty-nine chemicals were used in the comparison including 6 metals, 8 pesticides, 5 drugs, 4 solvents and 3 alcohols. The results of this study support the hypothesis that the mitochondrial bioassays can successfully predict the in vivo toxicity of many diverse chemicals. Properly performed and evaluated, these short-term tests may be useful in identifying potential environmental pollutants, selecting compounds for market development and prioritizing substances for more extensive testing in animals.
Arrhenius plots of Ca++-stimulated ATP hydrolysis by sarcoplasmic reticulum (SR) show breaks (Tt) at 16.7°C and 11.5°C for rabbit and lobster preparations, respectively. The energies of activation (Eact) are about 10 and 19.5 Kcal/mole above and below Tt, respectively, and are similar for both lobster and rabbit SR. The antibiotic filipin increases Tt by about 7°C for both preparations, but the Eact above and below the new Tt values remain similar to those of the controls. Desintegrated membranes do not show breaks in Arrhenius plots and the Eact assume relatively high values. The Ca++ ionophore X-537A does not affect either the Tt values nor the Eact.
The effects of phenoxyacid herbicides 2,4-D (2,4-dichlorophenoxyacetic acid) and MCPA (4-chloro-2-methylphenoxyacetic acid), clofibrate, and glyphosate on hepatic and intestinal drug metabolizing enzyme activities were studied in rats intragastrically exposed for 2 weeks. The hepatic ethoxycoumarin O-deethylase activity increased about 2-fold with MCPA. Both 2,4-D and MCPA increased the hepatic epoxide hydrolase activity and decreased the hepatic glutathione S-transferase activity. MCPA also increased the intestinal activities of ethoxycoumarin O-deethylase and epoxide hydrolase. Glyphosate decreased the hepatic level of cytochrome P-450 and monooxygenase activities and the intestinal activity of aryl hydrocarbon hydroxylase. Clofibrate decreased the hepatic activities of UDPglucuronosyltransferase with p-nitrophenol or methylumbelliferone as the substrate. Also 2,4-D decreased the hepatic activity of UDPglucuronosyltransferase with p-nitrophenol as the substrate. MCPA decreased the intestinal activities of UDPglucuronosyltransferase with either p-nitrophenol or methylumbelliferone as the substrate. The results indicate that phenoxyacetic acids, especially MCPA, may have potent effects on the metabolism of xenobiotics. Glyphosate, not chemically related to phenoxyacids, seems to inhibit monooxygenases. Whether these changes are related to the toxicity of these xenobiotics remains to be clarified in further experiments.
In this work, the mitochondrial transmembrane electric potential (delta psi) of isolated mitochondria was used to evaluate the toxicity of some chemicals (endosulfan, 3,4-dichloroaniline, parathion, tributyltin and cadmium) and wastewater. Mitochondria were isolated from rat liver, and the delta psi measured in a suitable assay medium, using a sensitive tetraphenylphosphonium (TPP+) electrode. The test substance was pre-incubated in a rotenone-containing medium during 3 min with 1.0 mg of mitochondrial protein. Mitochondria were energised with succinate and after the establishment of a constant maximal potential ADP was added to induce the phosphorylative cycle. Chosen endpoints were the membrane potential from mitochondria oxidising succinate and the depolarisation induced by ADP. After the appropriate transformations the EC50 (effective concentration) was calculated for each toxicant. Even very low concentrations of a toxicant were able to affect the delta psi, thus showing its suitability as a biosensor in ecotoxicology and results were reproducible between tests. The utilisation of delta psi in screening tests of pure substances and wastewater seems to be very effective and can be carried out routinely.
Reviews on the safety of glyphosate and Roundup herbicide that have been conducted by several regulatory agencies and scientific institutions worldwide have concluded that there is no indication of any human health concern. Nevertheless, questions regarding their safety are periodically raised. This review was undertaken to produce a current and comprehensive safety evaluation and risk assessment for humans. It includes assessments of glyphosate, its major breakdown product [aminomethylphosphonic acid (AMPA)], its Roundup formulations, and the predominant surfactant [polyethoxylated tallow amine (POEA)] used in Roundup formulations worldwide. The studies evaluated in this review included those performed for regulatory purposes as well as published research reports. The oral absorption of glyphosate and AMPA is low, and both materials are eliminated essentially unmetabolized. Dermal penetration studies with Roundup showed very low absorption. Experimental evidence has shown that neither glyphosate nor AMPA bioaccumulates in any animal tissue. No significant toxicity occurred in acute, subchronic, and chronic studies. Direct ocular exposure to the concentrated Roundup formulation can result in transient irritation, while normal spray dilutions cause, at most, only minimal effects. The genotoxicity data for glyphosate and Roundup were assessed using a weight-of-evidence approach and standard evaluation criteria. There was no convincing evidence for direct DNA damage in vitro or in vivo, and it was concluded that Roundup and its components do not pose a risk for the production of heritable/somatic mutations in humans. Multiple lifetime feeding studies have failed to demonstrate any tumorigenic potential for glyphosate. Accordingly, it was concluded that glyphosate is noncarcinogenic. Glyphosate, AMPA, and POEA were not teratogenic or developmentally toxic. There were no effects on fertility or reproductive parameters in two multigeneration reproduction studies with glyphosate. Likewise there were no adverse effects in reproductive tissues from animals treated with glyphosate, AMPA, or POEA in chronic and/or subchronic studies. Results from standard studies with these materials also failed to show any effects indicative of endocrine modulation. Therefore, it is concluded that the use of Roundup herbicide does not result in adverse effects on development, reproduction, or endocrine systems in humans and other mammals. For purposes of risk assessment, no-observed-adverse-effect levels (NOAELs) were identified for all subchronic, chronic, developmental, and reproduction studies with glyphosate, AMPA, and POEA. Margins-of-exposure for chronic risk were calculated for each compound by dividing the lowest applicable NOAEL by worst-case estimates of chronic exposure. Acute risks were assessed by comparison of oral LD50 values to estimated maximum acute human exposure. It was concluded that, under present and expected conditions of use, Roundup herbicide does not pose a health risk to humans.
This 54-year-old man accidentally sprayed himself with the chemical agent glyphosate, a herbicide derived from the amino acid glycine. He developed disseminated skin lesions 6 hours after the accident. One month later, he developed a symmetrical parkinsonian syndrome. Two years after the initial exposure to glyphosate, magnetic resonance imaging revealed hyperintense signal in the globus pallidus and substantia nigra, bilaterally, on T2-weighted images. Levodopa/benserazide 500/125 mg daily provided satisfactory clinical outcome.
Experimental studies were performed on healthy, 80-100 g carp (Cyprinus carpio). Fish were exposed by emersion in Roundup (205 mg of glyphosate/l or 410 mg of glyphosate/l) in concentrations of 40- to 20-fold lower than those used in practice. Electron microscopy revealed that the herbicide caused appearance of myelin-like structures in carp hepatocytes, swelling of mitochondria and disappearance of internal membrane of mitochondria in carp at both exposure concentrations. It means that Roundup was harmful to carp when used in applied concentrations. Results of these studies enhance our knowledge of ultrastructural pathomorphology of fish organs following exposure to Roundup.
To assess human health risk from environmental chemicals, we have studied the effect on cell cycle regulation of the widely used glyphosate-containing pesticide Roundup. As a model system we have used sea urchin embryonic first divisions following fertilization, which are appropriate for the study of universal cell cycle regulation without interference with transcription. We show that 0.8% Roundup (containing 8 mM glyphosate) induces a delay in the kinetic of the first cell cleavage of sea urchin embryos. The delay is dependent on the concentration of Roundup. The delay in the cell cycle could be induced using increasing glyphosate concentrations (1-10 mM) in the presence of a subthreshold concentration of Roundup 0.2%, while glyphosate alone was ineffective, thus indicating synergy between glyphosate and Roundup formulation products. The effect of Roundup was not lethal and involved a delay in entry into M-phase of the cell cycle, as judged cytologically. Since CDK1/cyclin B regulates universally the M-phase of the cell cycle, we analyzed CDK1/cyclin B activation during the first division of early development. Roundup delayed the activation of CDK1/cyclin B in vivo. Roundup inhibited also the global protein synthetic rate without preventing the accumulation of cyclin B. In summary, Roundup affects cell cycle regulation by delaying activation of the CDK1/cyclin B complex, by synergic effect of glyphosate and formulation products. Considering the universality among species of the CDK1/cyclin B regulator, our results question the safety of glyphosate and Roundup on human health.
The parasitic plant Cuscuta campestris is dependent on its host for water, assimilates and amino acids. It can be controlled by the herbicide glyphosate, which inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), resulting in shikimate accumulation. In this study, C. campestris was parasitic on transgenic tobacco plants expressing green fluorescent protein (GFP) in the phloem. Changes in [14C]sucrose and GFP accumulation in the parasite were used as indicators of the herbicide's effect on translocation between the host and parasite. Host plants were treated with glyphosate 22 days after sowing. Shikimate accumulation in the parasite 1 day after glyphosate treatment (DAGT) confirmed EPSPS inhibition in C. campestris. No damage was visible in the host plants for the first 3 DAGT, while during that same time, a significant reduction in [14C]sucrose and GFP accumulation was observed in the parasite. Thus, we propose that the parallel reduction in GFP and sucrose accumulation in C. campestris is a result of a glyphosate effect on the parasite's ability to withdraw assimilates from the host.
Glyphosate-based herbicides are among the most widely used pesticides in the world. We compared the acute toxicity of the glyphosate end-use formulation Roundup Original to four North American amphibian species (Rana clamitans, R. pipiens, R. sylvatica, and Bufo americanus) and the toxicity of glyphosate technical, the polyethoxylated tallowamine surfactant (POEA) commonly used in glyphosate-based herbicides, and five newer glyphosate formulations to R. clamitans. For R. clamitans, acute toxicity values in order of decreasing toxicity were POEA > Roundup Original > Roundup Transorb > Glyfos AU; no significant acute toxicity was observed with glyphosate technical material or the glyphosate formulations Roundup Biactive, Touchdown, or Glyfos BIO. Comparisons between the four amphibian species showed that the toxicity of Roundup Original varied with species and developmental stage. Rana pipiens tadpoles chronically exposed to environmentally relevant concentrations of POEA or glyphosate formulations containing POEA showed decreased snout-vent length at metamorphosis and increased time to metamorphosis, tail damage, and gonadal abnormalities. These effects may be caused, in some part, by disruption of hormone signaling, because thyroid hormone receptor beta mRNA transcript levels were elevated by exposure to formulations containing glyphosate and POEA. Taken together, the data suggest that surfactant composition must be considered in the evaluation of toxicity of glyphosate-based herbicides.
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