Disruption of cytochrome P450 enzymes in the liver and small intestine in chicken embryos in ovo exposed to glyphosate

Childhood and adolescent residential and farm pesticide exposures and inflammatory bowel disease incidence in a U.S. cohort of women

BACKGROUND AND AIMS

There are few known risk factors for inflammatory bowel disease (IBD), an autoimmune disease characterized by chronic intestinal inflammation. Use of specific pesticides has been associated with higher incidence of IBD among pesticide applicators and their spouses, but no study has examined pesticide exposure in early life, a period where the human immune system undergoes rapid changes. We evaluated pesticide use during childhood and adolescence and incidence of IBD among US women enrolled in the Sister Study.

METHODS

Incident IBD diagnoses between enrollment (2003-2009) and 2021 were identified and validated with medication use and colectomy/colostomy surgery. We estimated hazard ratios (HR) and 95 % confidence intervals (CI) for the relationship of childhood/adolescent residential and farm pesticide exposures with IBD incidence using Cox models, accounting for age, race and ethnicity, education, smoking, and birth year.

RESULTS

We identified 277 incident IBD cases among 48,382 eligible participants. IBD hazard was elevated among those whose childhood residence was regularly treated with pesticides, especially among those who ever personally applied pesticides (HR = 1.39, 95%CI: 0.65, 2.99). We observed a positive association between IBD and exposure to broadcast pesticide sprays before DDT was banned (>6 times vs. never HR = 1.56, 95%CI: 1.06, 2.31). Among participants who lived on a farm during childhood/adolescence for ≥1 year (N = 9162), IBD hazards were higher among those who were in crop fields during pesticide application (HR = 2.06, 95%CI: 0.94, 4.51) and who ever personally applied pesticides on crops (HR = 1.85, 95%CI: 0.81, 4.18) or livestock (HR = 2.58, 95%CI: 1.14, 5.83).

CONCLUSION

Early-life pesticide exposure may be a novel risk factor for IBD. Practices that reduce pesticide exposure during early life may help reduce the burden of this disease.

Chronic dietary exposure to a glyphosate-based herbicide alters ovarian functions in young female broilers

Glyphosate (GLY)-based herbicide (GBH) formulations are widely used pesticides in agriculture. The European Union recently decided to extend the use of GLY in Europe until 2034. Previously, we showed that chronic dietary GBH exposure in adult hens resulted in a reversible increase in early mortality in chicken embryos. In this present study, we investigated the GBH effects on metabolism and ovarian functions by using a transcriptomic approach in vivo in young female broilers and in vitro in ovarian explant cultures. We exposed 11-day-old female broilers to 13 mg GLY equivalent/kg body weight/d (GBH13, n = 20), 34 mg GLY equivalent/kg body weight/d (GBH34, n = 20), or a standard diet (control [CT], n = 20) for 25 d. These 2 GBH concentrations correspond to approximatively one-eighth and one-third of the no observed adverse effect level (NOAEL) as defined by European Food Safety Authority in birds. During this period, we evaluated body weight, fattening, food intake, and the weight of organs (including the ovaries). Chronic dietary GBH exposure dose dependently reduced food intake, body weight, and fattening, but increased oxidative stress and relative ovary weight. We analyzed the ovarian gene expression profile in CT, GBH13, and GBH34 broilers with RNA sequencing and showed that differentially expressed genes are mainly enriched in pathways related to cholesterol metabolism, steroidogenesis, and RNA processing. With quantitative polymerase chain reaction and western blotting, we confirmed that GBH decreased ovarian STAR and CYP19A1 messenger RNA and protein expression, respectively. Furthermore, we confirmed that GBH altered steroid production in ovarian explants. We have identified potential regulatory networks associated with GBH. These data provide valuable support for understanding the ovarian transcriptional regulatory mechanism of GBH in growing broilers.

Pesticide use and inflammatory bowel disease in licensed pesticide applicators and spouses in the Agricultural Health Study

BACKGROUND

Pesticide exposure has been linked to some autoimmune diseases and colorectal cancer, possibly via alteration of gut microbiota or other mechanisms. While pesticides have been linked to gut dysbiosis and inflammation in animal models, few epidemiologic studies have examined pesticides in relation to inflammatory bowel disease (IBD).

OBJECTIVES

We evaluated use of pesticides and incident IBD in 68,480 eligible pesticide applicators and spouses enrolled in the Agricultural Health Study.

METHODS

Self-reported IBD cases were identified from follow-up questionnaires between enrollment (1993-1997) and 2022. We evaluated IBD incidence in relation to self-reported ever use of 50 pesticides among applicators and spouses. We also explored associations with intensity-weighted lifetime days (IWLD) of pesticide use among male applicators. Covariate-adjusted hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox regression.

RESULTS

We identified 454 IBD cases, including 227 among male applicators. In analyses with applicators and spouses combined, associations were positive (HR > 1.2) for ever vs. never use of five organochlorine insecticides, three organophosphate insecticides, one fungicide, and five herbicides. HRs were highest for dieldrin (HR = 1.59, 95%CI: 1.03, 2.44), toxaphene (HR = 1.61, 95%CI: 1.17, 2.21), parathion (HR = 1.42, 95%CI: 1.03, 1.95), and terbufos (HR = 1.53, 95%CI: 1.19, 1.96). We had limited power in many IWLD of pesticide use analyses and did not find clear evidence of exposure-response trends; however, we observed elevated HRs in all tertiles of IWLD use of terbufos compared to never use (T1 vs. never use HR = 1.52, 95%CI: 1.03, 2.24; T2 vs. never use HR = 1.53, 95%CI: 1.04, 2.26; T3 vs. never use HR = 1.51, 95%CI: 1.03, 2.23).

CONCLUSIONS

Exposure to specific pesticides was associated with elevated hazards of IBD. These findings may have public health importance given the widespread use of pesticides and the limited number of known modifiable environmental risk factors for IBD.

Exposure of the stingless bee Melipona scutellaris to imidacloprid, pyraclostrobin, and glyphosate, alone and in combination, impair its walking activity and fat body morphology and physiology

The stingless bee Melipona scutellaris performs buzz pollination, effectively pollinating several wild plants and crops with economic relevance. However, most research has focused on honeybees, leaving a significant gap in studies concerning native species, particularly regarding the impacts of pesticide combinations on these pollinators. Thus, this study aimed to evaluate the sublethal effects of imidacloprid (IMD), pyraclostrobin (PYR), and glyphosate (GLY) on the behavior and fat body cell morphology and physiology of M. scutellaris. Foragers were orally exposed to the different pesticides alone and in combination for 48 h. Bees fed with contaminated solution walked less, moved slower, presented morphological changes in the fat body, including vacuolization, altered cell shape and nuclei morphology, and exhibited a higher count of altered oenocytes and trophocytes. In all exposed groups, alone and in combination, the number of cells expressing caspase-3 increased, but the TLR4 number of cells expressing decreased compared to the control groups. The intensity of HSP70 immunolabeling increased compared to the control groups. However, the intensity of the immunolabeling of HSP90 decreased in the IMD, GLY, and I + G (IMD + GLY) groups but increased in I + P-exposed bees (IMD + PYR). Alternatively, exposure to PYR and P + G (PYR + GLY) did not affect the immunolabeling intensity. Our findings demonstrate the hazardous effects and environmental consequences of isolated and combined pesticides on a vital neotropical pollinator. Understanding how pesticides impact the fat body can provide crucial insights into the overall health and survival of native bee populations, which can help develop more environmentally friendly approaches to agricultural practices.

Glyphosate-induced changes in the expression of galanin and GALR1, GALR2 and GALR3 receptors in the porcine small intestine wall

Glyphosate is the active ingredient of glyphosate-based herbicides and the most commonly used pesticide in the world. The goal of the present study was to verify whether low doses of glyphosate (equivalent to the environmental exposure) evoke changes in galanin expression in intramural neurons in the small intestine in pigs and to quantitatively determine changes in the level of galanin receptor encoding mRNA (GALR1, GALR2, GALR3) in the small intestine wall. The experiment was conducted on 15 sexually immature gilts divided into three study groups: control (C)-animals receiving empty gelatin capsules; experimental 1 (G1)-animals receiving a low dose of glyphosate (0.05 mg/kg b.w./day); experimental 2 (G2)-animals receiving a higher dose of glyphosate (0.5 mg/kg b.w./day) orally in gelatine capsules for 28 days. Glyphosate ingestion led to an increase in the number of GAL-like immunoreactive intramural neurons in the porcine small intestine. The results of RT-PCR showed a significant increase in the expression of mRNA, which encodes the GAL-receptors in the ileum, a decreased expression in the duodenum and no significant changes in the jejunum. Additionally, intoxication with glyphosate increased the expression of SOD2-encoding mRNA in the duodenum and decreased it in the jejunum and ileum, but it did not affect SOD1 expression. The results suggest that it may be a consequence of the cytotoxic and/or neurotoxic properties of glyphosate and/or its ability to induce oxidative stress.

The exposure in ovo to glyphosate on the integrity of intestinal epithelial tight junctions of chicks

Glyphosate is an ingredient widely used in various commercial formulations, including Roundup®. This study focused on tight junctions and the expression of inflammatory genes in the small intestine of chicks. On the sixth day of embryonic development, the eggs were randomly assigned to three groups: the control group (CON, n = 60), the glyphosate group (GLYP, n = 60), which received 10 mg of active glyphosate/kg egg mass, and the Roundup®-based glyphosate group also received 10 mg of glyphosate. The results indicated that the chicks exposed to glyphosate or Roundup® exhibited signs of oxidative stress. Additionally, histopathological alterations in the small intestine tissues included villi fusion, complete fusion of some intestinal villi, a reduced number of goblet cells, and necrosis of some submucosal epithelial cells in chicks. Genes related to the small intestine (ZO-1, ZO-2, Claudin-1, Claudin-3, JAM2, and Occludin), as well as the levels of pro-inflammatory cytokines (IFNγ, IL-1β, and IL-6), exhibited significant changes in the groups exposed to glyphosate or Roundup® compared to the control group. In conclusion, the toxicity of pure glyphosate or Roundup® likely disrupts the small intestine of chicks by modulating the expression of genes associated with tight junctions in the small intestine.

Involvement of glyphosate in disruption of biotransformation P450 enzymes and hepatic lipid metabolism in chicken

The current study investigated the potentially harmful consequences of pure glyphosate or Roundup® on CYP family members and lipid metabolism in newly hatched chicks. On the sixth day, 225 fertilized eggs were randomly divided into three treatments: (1) the control group injected with deionized water, (2) the glyphosate group injected with 10 mg pure glyphosate/Kg egg mass and (3) the Roundup group injected 10 mg the active ingredient glyphosate in Roundup®/Kg egg. The results of the study revealed a reduction in hatchability in chicks treated with Roundup®. Moreover, change of Lipid concentration in serum and the liver-treated groups. Additionally, increased liver function enzymes and increased oxidative stress in the glyphosate and Roundup® groups. Furthermore, liver tissues showed histological changes and several lipid deposits in glyphosate-treated groups. Hepatic CYP1A2 and CYP1A4 expressions were significantly increased (p < .05) after glyphosate exposure, and suppression of CYP1C1 mRNA expression was significant (p < .05) after Roundup® exposure. The pro-inflammatory cytokines genes IFN-γ and IL-1β expression were significantly increased (p < .05) after Roundup® exposure. In addition, there were significant differences in the levels of expression genes which are related to lipid synthesis or catabolism in the liver. In conclusion, in ovo glyphosate exposure caused disruption of biotransformation, pro-inflammatory and lipid metabolism in chicks.

Organophosphorus and carbamate pesticides: Molecular toxicology and laboratory testing

Population and food requirements are increasing daily throughout the world. To fulfil these requirements application of pesticides is also increasing. Organophosphorous (OP) and Organocarbamate (OC) compounds are widely used pesticides. These pesticides are used for suicidal purposes too. Both inhibit Acetylcholinesterase (AChE) and cholinergic symptoms are mainly used for the diagnosis of pesticide poisoning. Although the symptoms of the intoxication of OP and OC are similar, recent research has described different targets for OP and OC pesticides. Researchers believe the distinction of OP/OC poisoning will be beneficial for the management of pesticide exposure. OP compounds produce adducts with several proteins. There is a new generation of OP compounds like glyphosate that do not inhibit AChE. Therefore, it's high time to develop biomarkers that can distinguish OP poisoning from OC poisoning.

In ovo injection of soy isoflavones on hatching performance and intestinal development of newly hatched chicks

This study aimed to evaluate the effects of in ovo injection of soy isoflavones (ISF) on hatchability, body weight, antioxidant status and intestinal development of newly hatched broiler chicks. One hundred and eighty fertile eggs were divided as follows: the control group, 3 mg/egg ISF (low dose) and 6 mg/egg ISF (high dose) on the 18th day of incubation. The results demonstrated that in ovo inclusion of 6 mg of ISF significantly increased hatchability and hatch weight. Both doses of ISF inclusion elevated the serum glutathione peroxidase and slightly decreased malondialdehyde compared to the control group. The high dose of ISF brings higher villus height and a higher villus/crypt ratio in chicks. Moreover, the mRNA levels of tumour necrosis factor- α and interferon-gamma in the spleen were significantly decreased. The ISF treatments showed an improvement in intestinal enzyme expression levels of sucrose isomaltase and mucin 2  as well as tight junction protein (TJ) mRNA expression of claudin-1 at high doses of ISF (p < 0.05) when compared with the other groups. Furthermore, the mRNA level of IGF-1 was increased in the high doses of ISF compared to the control. Overall, these findings indicate that in ovo administration of ISF on the 18th day of incubation enhances hatchability, antioxidant status and intestinal morphometrics in hatched chicks and modulates the expression of proinflammatory cytokines, TJs and insulin-like growth factor. In addition, the sustainability of antioxidants and other positive effects of ISF may increase chick viability and growth performance.

Glyphosate metabolism in Tetrahymena thermophila: A shotgun proteomic analysis approach

Glyphosate is one of the most widely used herbicides in the world. However, because of its overuse and resistance to degradation, high levels of glyphosate residues in the environment are reported. Therefore, this study aimed to investigate the effects of glyphosate on proteomic aspects of Tetrahymena thermophila and their uses as bioindicators of freshwater ecosystem. First, an acute toxicity test was performed to determine the median inhibition concentration (IC₅₀ ). The toxicity test results showed that glyphosate inhibited the growth (proliferation) of T. thermophila. The 96 h-IC₅₀ value of glyphosate was 171 mg L^-1 . No visible changes in aggregation behavior and cell morphology were observed under glyphosate exposure. In addition, the effects of low and high dose glyphosate concentrations (77.5 mg L^-1 , 171 mg L^-1 ) on the proteomic changes of T. thermophila was investigated using a label-free shotgun proteomic approach. A total of 3191 proteins were identified, 2791 proteins were expressed in the control, 2651 proteins were expressed in 77.5 mg L^-1 glyphosates, and 3012 proteins were expressed in 171 mg L^-1 glyphosates. Under glyphosate exposure at both low and high dose glyphosate, 400 unique proteins were upregulated. The majority of these proteins was classified as proteins associated with oxidative stress response and intracellular transport indicating the shifts in the internal metabolism. Proteomics revealed that the glyphosate metabolism by T. thermophila is a multi-step process involving several enzymes, which can be divided into four phases, including modification (phase I), conjugation (phase II), transport (phase III), and degradation (phase IV). The accumulation of various biochemical reactions contributes to overall glyphosate resistance. With the proteomics approach, we have found that T. thermophila was equipped with glyphosate detoxification and degradation mechanisms.

Antioxidant Enzyme and Cytochrome P450 Activities Are Involved in Horseweed (Conyza Sumatrensis) Resistance to Glyphosate

The intensive global use of glyphosate has led to the evolution of glyphosate resistant (GR) weed species, including the economically damaging horseweed (Conyza sumatrensis). We evaluated the glyphosate resistance mechanisms of C. sumatrensis. While 5-enolpyruvylshikimate-3-phosphate synthase activity was similar between the glyphosate resistant (GR) and nonresistant biotypes, plants from the GR population accumulated lower shikimate levels than susceptible ones, suggesting the absence of target-site resistance mechanisms. Decreases over time in glyphosate concentrations in GR leaves were not accompanied by increases in glyphosate concentrations in their stem and roots, indicating lower glyphosate distribution rates in GR plants. The early appearance of aminomethylphosphonic acid (the main glyphosate metabolite) in leaves, as well as its presence only in the stems and roots of GR plants, suggests faster glyphosate metabolism in GR plants than in susceptible ones. GR plants treated with glyphosate also showed greater antioxidant (ascorbate peroxidase [APX] and catalase [CAT]) and cytochrome P450-enzyme activities, indicating their great capacity to avoid glyphosate-induced oxidative stress. Three non-target mechanisms (reduced glyphosate translocation, increased metabolism, and increased antioxidant activity) therefore confer glyphosate resistance in C. sumatrensis plants. This is the first time that APX, CAT and P450-enzyme activities are related to GR in C. sumatrensis.

Probiotics ameliorate growth retardation of glyphosate by regulating intestinal microbiota and metabolites in crucian carp (Carassius auratus)

Glyphosate (GLY) contamination widely occurred in aquatic environments including aquaculture systems and raised hazard to aquatic organisms such as fish. Probiotics have been reported to alleviate contaminants-induced toxicity. However, whether probiotics could reduce the health risk of GLY to fish remain unknown. Here we investigated the impacts of GLY on crucian carp (Carassius auratus) by focusing on the protective roles of two commonly used aquaculture probiotics, Bacillus coagulans (BC) and Clostridium butyricum (CB). Exposure to GLY significantly caused growth retardation and reduced visceral fat and intestinal lipase activity in crucian carp. 16S rRNA sequencing indicated that dysbiosis of Bacteroidetes at phylum level and Flavobacterium at genus level might be primarily responsible for GLY-induced negative growth performance. High throughput targeted quantification for metabolites revealed that GLY changed intestinal metabolites profiles, especially the reduced bile acids and short-chain fatty acids. However, the addition of BC or CB effectively attenuated the adverse effects above by remodeling the gut microbiota composition and improving microbial metabolism. The present study provides novel evidence for ameliorating the harmful effects of GLY on fish species by adding probiotics, which highlights the potential application of probiotics in reducing the health risks of GLY in aquatic environment.

Chronic dietary exposure to a glyphosate-based herbicide results in total or partial reversibility of plasma oxidative stress, cecal microbiota abundance and short-chain fatty acid composition in broiler hens

Glyphosate-based herbicides (GBHs) are massively used in agriculture. However, few studies have investigated the effects of glyphosate-based herbicides on avian species although they are largely exposed via their food. Here, we investigated the potential reversibility of the effects of chronic dietary exposure to glyphosate-based herbicides in broiler hens. For 42 days, we exposed 32-week-old hens to glyphosate-based herbicides via their food (47 mg/kg/day glyphosate equivalent, glyphosate-based herbicides, n = 75) corresponding to half glyphosate’s no-observed-adverse-effect-level in birds. We compared their performance to that of 75 control animals (CT). Both groups (glyphosate-based herbicides and control animals) were then fed for 28 additional days without glyphosate-based herbicides exposure (Ex-glyphosate-based herbicides and Ex-control animals). Glyphosate-based herbicides temporarily increased the plasma glyphosate and AMPA (aminomethylphosphonic acid) concentrations. Glyphosate and aminomethylphosphonic acid mostly accumulated in the liver and to a lesser extent in the leg muscle and abdominal adipose tissue. Glyphosate-based herbicides also temporarily increased the gizzard weight and plasma oxidative stress monitored by TBARS (thiobarbituric acid reactive substances). Glyphosate-based herbicides temporarily decreased the cecal concentrations of propionate, isobutyrate and propionate but acetate and valerate were durably reduced. The cecal microbiome was also durably affected since glyphosate-based herbicides inhibited Barnesiella and favored Alloprevotella. Body weight, fattening, food intake and feeding behavior as well as plasma lipid and uric acid were unaffected by glyphosate-based herbicides. Taken together, our results show possible disturbances of the cecal microbiota associated with plasma oxidative stress and accumulation of glyphosate in metabolic tissues in response to dietary glyphosate-based herbicides exposure in broiler hens. Luckily, glyphosate-based herbicides at this concentration does not hamper growth and most of the effects on the phenotypes are reversible.

How advanced are we on the consequences of oral exposure to food contaminants on the occurrence of chronic non communicable diseases?

The development of an individual during fetal life and childhood is characterized by rapid growth as well as gradual maturation of organs and systems. Beyond the nutritional intake in essential nutrients, food contaminants can permanently influence the way organs mature and function. These processes are called "programming" and play an essential role in the occurrence of non-communicable chronic diseases throughout the lifespan. Populations as pregnant women, fetuses and young children are vulnerable and particularly sensitive to food contaminants which can induce epigenetic modifications transmissible to future generations. Among these contaminants, pesticides are found in most food matrices exposing humans to cocktails of molecules through variable concentrations and duration of exposure. The Maillard reaction products (MRPs) represent other food contaminants resulting from heat treatment of food. Modern diet, rich in fats and sugars, is also rich in neoformed pathogenic compounds, Advanced Glycation End products (AGEs), the levels of which depend on the heat treatment of foods and eating habits and whose effects on health are controversial. In this review, we have chosen to present the current knowledge on the impacts of selected pesticides and MRPs, on the risk of developing during life non-communicable chronic diseases such as IBD, metabolic disorders or allergies. A large review of literature was performed via Pubmed, and the most appropriate studies were summarised.

Chronic dietary exposure to a glyphosate-based herbicide results in reversible increase early embryo mortality in chicken

Glyphosate (Gly) is the active molecule of non-selective herbicides used in conventional agriculture. Some evidence shows that exposure to Glyphosate-Based Herbicides (GBH) can affect both male and female fertility in animal models. However, few data exist on birds that can be easily exposed through their cereal-based diet. To our knowledge, there are no current studies on the effects of chronic dietary exposure to GBH and the potential reversibility on the fertility and embryo development in chickens. In our protocol, hens (32 weeks-old) were exposed to GBH (47 mg kg-1/day-1 glyphosate equivalent corresponding to half of the No-Observed-Adverse-Effect-Level (NOAEL) as defined by European Food Safety Authority in birds, GBH group (GBH), n = 75) or not (Control group (CT), n = 75) for 6 weeks. Then, both CT and GBH groups were fed for 5 more weeks without GBH exposure. During these two periods, we investigated the consequences on the egg performance and quality, fertilization rate, embryo development, and viability of offspring. Despite the accumulation of Gly and its metabolite aminomethylphosphonic acid (AMPA) in the hen blood plasma, the body weight and laying rate were similar in GBH and CT animals. We observed from the 4th day of exposure an accumulation of Gly (but not AMPA) only in the yolk of the eggs produced by the exposed hens. After artificial insemination of the hens followed by eggs incubation, we showed a strong significant early embryonic mortality level in GBH compared to CT animals (78 ± 2 % vs 2.5 ± 0.3 %, p < 0.0001) with embryo death mainly occurring on the third day of incubation. By using computed tomography (CT) and magnetic resonance imaging (MRI) tools, we noted a significant delay in the embryo development of GBH survivors at 15 days with a reduction by half of the embryo volume and some disturbances in the calculated volumes of the embryonic annexes. At 20 days of incubation, we showed a reduction in the length of the tibia and in the volume of the soft tissues whereas the skeleton volume was increased in GBH chicks. The vast majority of these phenotypes disappeared two weeks after an arrest of the GBH maternal dietary exposure. Taken together, the dietary chronic exposure of broiler hens to GBH at a Gly equivalent concentration lower than NOAEL induces an accumulation of Gly in the egg yolk resulting in severe early embryonic mortality and a delayed embryonic development in survivors that were abolished two weeks after the end of GBH exposure.

Oxidative Stress and Metabolism: A Mechanistic Insight for Glyphosate Toxicology

Glyphosate (GLYP) is a widely used pesticide; it is considered to be a safe herbicide for animals and humans because it targets 5-enolpyruvylshikimate-3-phosphate synthase. However, there has been increasing evidence that GLYP causes varying degrees of toxicity. Moreover, oxidative stress and metabolism are highly correlated with toxicity. This review provides a comprehensive introduction to the toxicity of GLYP and, for the first time, systematically summarizes the toxicity mechanism of GLYP from the perspective of oxidative stress, including GLYP-mediated oxidative damage, changes in antioxidant status, altered signaling pathways, and the regulation of oxidative stress by exogenous substances. In addition, the metabolism of GLYP is discussed, including metabolites,metabolic pathways, metabolic enzymes, and the toxicity of metabolites. This review provides new ideas for the toxicity mechanism of GLYP and proposes effective strategies for reducing its toxicity.

Chronic Dietary Exposure of Roosters to a Glyphosate-Based Herbicide Increases Seminal Plasma Glyphosate and AMPA Concentrations, Alters Sperm Parameters, and Induces Metabolic Disorders in the Progeny

The effects of chronic dietary Roundup (RU) exposure on rooster sperm parameters, fertility, and offspring are unknown. We investigated the effects of chronic RU dietary exposure (46.8 mg kg⁻¹ day⁻¹ glyphosate) for 5 weeks in 32-week-old roosters (n = 5 RU-exposed and n = 5 control (CT)). Although the concentrations of glyphosate and its main metabolite AMPA (aminomethylphosphonic acid) increased in blood plasma and seminal fluid during exposure, no significant differences in testis weight and sperm concentrations were observed between RU and CT roosters. However, sperm motility was significantly reduced, associated with decreased calcium and ATP concentrations in RU spermatozoa. Plasma testosterone and oestradiol concentrations increased in RU roosters. These negative effects ceased 14 days after RU removal from the diet. Epigenetic analysis showed a global DNA hypomethylation in RU roosters. After artificial insemination of hens (n = 40) with sperm from CT or RU roosters, eggs were collected and artificially incubated. Embryo viability did not differ, but chicks from RU roosters (n = 118) had a higher food consumption, body weight and subcutaneous adipose tissue content. Chronic dietary RU exposure in roosters reduces sperm motility and increases plasma testosterone levels, growth performance, and fattening in offspring.

Review: Mechanisms of Glyphosate and Glyphosate-Based Herbicides Action in Female and Male Fertility in Humans and Animal Models

Glyphosate (G), also known as N-(phosphonomethyl)glycine is the declared active ingredient of glyphosate-based herbicides (GBHs) such as Roundup largely used in conventional agriculture. It is always used mixed with formulants. G acts in particular on the shikimate pathway, which exists in bacteria, for aromatic amino acids synthesis, but this pathway does not exist in vertebrates. In recent decades, researchers have shown by using various animal models that GBHs are endocrine disruptors that might alter reproductive functions. Our review describes the effects of exposure to G or GBHs on the hypothalamic-pituitary-gonadal (HPG) axis in males and females in terms of endocrine disruption, cell viability, and proliferation. Most of the main regulators of the reproductive axis (GPR54, GnRH, LH, FSH, estradiol, testosterone) are altered at all levels of the HPG axis (hypothalamus, pituitary, ovaries, testis, placenta, uterus) by exposure to GBHs which are considered more toxic than G alone due to the presence of formulants such as polyoxyethylene tallow amine (POEA)." In addition, we report intergenerational impacts of exposure to G or GBHs and, finally, we discuss different strategies to reduce the negative effects of GBHs on fertility.

Impact of Glyphosate-Roundup® in the Ileal Structure of Male and Female Rats: A Morphological and Immunohistochemical Study

The current study was aimed to evaluate the effects of variable doses of the weedicide glyphosate on the ileal (the final section of the small intestine) structure of rats of both sexes, using histological, histochemical, and ultrastructural methods. Forty animals were classified into four groups of 10 animals per group (five males and five females). The first group acted as a control, and the remaining groups were treated with glyphosate-Roundup® 25, 50, and 100 mg/kg body weight daily for 15 days. The results indicated extinct histopathological changes manifested in the deformation of villi, foci of leukocytic infiltration in the core of villi, and hyperplasia of goblet cells. Histochemical examination (Alcian blue and Periodic acid-Schiff stain) revealed a strong positive reaction of goblet cells and an increase in their number in all treated groups. In addition, the immunohistochemical investigation revealed the immunoreactivity of matrix metalloproteinase-9 expression. Furthermore, electron microscopic alternations were represented by the deformation of nuclei, destruction of microvilli, and deposition of lipid droplets. Collectively, the present findings indicate that treatment with glyphosate results in extensive morphological alternations to the ileal structure of rats of both sexes and that female rats are more affected than male rats are.

Dimethyl Sulfoxide: Morphological, Histological, and Molecular View on Developing Chicken Liver

Dimethyl sulfoxide (DMSO) is widely used as a solvent for small hydrophobic drug molecules. However, the safe volume allowing to avoid its embryotoxic effect has been poorly studied. In this study, we documented the effects of dimethyl sulfoxide (DMSO) in the developing chicken embryo at morphological, histological, and molecular levels. We focused on the developing chicken liver as the main organ involved in the process of detoxification. In our study, 100% DMSO was administered subgerminally onto the eggshell membrane (membrana papyracea) at various volumes (5, 10, 15, 20, 25, 30, 35, and 50 µL) on 4th embryonic day (ED). We focused on histopathological alterations of the liver structure, and noticed the overall impact of DMSO on developing chicken embryos (embryotoxicity, malformation). At the molecular level, we studied cytochrome P450 complex (CYP) isoform's activities in relation to changes of CYP1A5, CYP3A37, and CYP3A80 gene expression. Total embryotoxicity after application of different doses of DMSO on ED 4, and the embryo lethality increased with increasing DMSO amounts. Overall mortality after DMSO administration ranged below 33%. Mortality was increased with higher amounts of DMSO, mainly from 20 µL. The highest mortality was observed for the highest dose of DMSO over 35 µL. The results also showed a decrease in body weight with increased application volumes of DMSO. At the histological level, we observed mainly the presence of lipid droplets and dilated bile canaliculi and sinusoids in samples over the administration of 25 µL of DMSO. While these findings were not statistically significant, DMSO treatment caused a significant different up-regulation of mRNA expression in all studied genes. For CYP1A5, CYP3A37, and CYP3A80 DMSO volumes needed were 15 µL, 10 µL, and 20 µL, respectively. A significant down-regulation of all studied CYP isoform was detected after application of a DMSO dose of 5 µL. Regarding the morphological results, we can assume that the highest safe dose of DMSO without affecting chicken embryo development and its liver is up to 10 µL. This conclusion is corroborated with the presence of number of malformations and body weight reduction, which correlates with histological findings. Moreover, the gene expression results showed that even the lowest administered DMSO volume could affect hepatocytes at the molecular level causing down-regulation of cytochrome P450 complex (CYP1A5, CYP3A37, CYP3A80).

Environment permissible concentrations of glyphosate in drinking water can influence the fate of neural stem cells from the subventricular zone of the postnatal mouse

The developing nervous system is highly vulnerable to environmental toxicants especially pesticides. Glyphosate pesticide induces neurotoxicity both in humans and rodents, but so far only when exposed to higher concentrations. A few studies, however, have also reported the risk of general toxicity of glyphosate at concentrations comparable to allowable limits set up by environmental protection authorities. In vitro data regarding glyphosate neurotoxicity at concentrations comparable to maximum permissible concentrations in drinking water is lacking. In the present study, we established an in vitro assay based upon neural stem cells (NSCs) from the subventricular zone of the postnatal mouse to decipher the effects of two maximum permissible concentrations of glyphosate in drinking water on the basic neurogenesis processes. Our results demonstrated that maximum permissible concentrations of glyphosate recognized by environmental protection authorities significantly reduced the cell migration and differentiation of NSCs as demonstrated by the downregulation of the expression levels of the neuronal ß-tubulin III and the astrocytic S100B genes. The expression of the cytoprotective gene CYP1A1 was downregulated whilst the expression of oxidative stresses indicator gene SOD1 was upregulated. The concentration comparable to non-toxic human plasma concentration significantly induced cytotoxicity and activated Ca2+ signalling in the differentiated culture. Our findings demonstrated that the permissible concentrations of glyphosate in drinking water recognized by environmental protection authorities are capable of inducing neurotoxicity in the developing nervous system.

Transcriptomic and metabolomic landscape of the molecular effects of glyphosate commercial formulation on Apis mellifera ligustica and Apis cerana cerana

Understanding the causes of the decline in bee population has attracted intensive attention worldwide. The indiscriminate use of agrochemicals is a persistent problem due to their physiological and behavioural damage to bees. Glyphosate and its commercial formulation stand out due to their wide use in agricultural areas and non-crop areas, such as parks, railroads, roadsides, industrial sites, and recreational and residential areas, but the mode of action of glyphosate on bees at the molecular level remains largely unelucidated. Here, we found that the numbers of differentially expressed genes and metabolites under glyphosate commercial formulation (GCF) stress were significantly higher in Apis cerana cerana than in Apis mellifera ligustica. Despite these differences, the number of differentially expressed transcripts increased following an increase in the GCF treatment time in both A. cerana cerana and A. mellifera ligustica. GCF exerted adverse impacts on the immune system, digestive system, nervous system, amino acid metabolism, carbohydrate metabolism, growth and development of both bee species by influencing their key genes and metabolites to some extent. The expression of many genes involved in immunity, agrochemical detoxification and resistance, such as antimicrobial peptides, cuticle proteins and cytochrome P450 families, was upregulated by GCF in both bee species. Collectively, our results indicate that both A. cerana cerana and A. mellifera ligustica strive to mitigate the pernicious effects caused by GCF by regulating detoxification and immune systems. Moreover, A. cerana cerana might be better able to withstand the toxic effects of GCF with lower fitness costs than A. mellifera ligustica. Our work will contribute to elucidating the deleterious physiological and behavioural impacts of GCF on bees.

Egg Overspray with Herbicides and Fungicides Reduces Survival of Red-Legged Partridge Chicks

Within the environmental risk assessment conducted for pesticide registration in the European Union (EU), avian reproductive toxicity is characterized after exposing adults. However, eggs of ground-nesting species can be exposed when pesticide applications occur during laying or incubation. We simulated environmentally realistic exposure of red-legged partridge (Alectoris rufa) eggs to an herbicide (2,4-D) and a fungicide (tebuconazole) applied to winter cereal crops during the breeding season of most farmland birds. We analyzed the effects on hatching success, offspring survival, and physiology. Exposure by overspray led to greater pesticide accumulation in the eggshell or content than exposure through contact with treated soil (3.1-13.7 times higher, depending on the pesticide and target sample). Egg overspray with tebuconazole significantly increased chick mortality, which was 26% higher than that of controls. 2,4-D caused a similar but a close to significant increase (chick mortality 24% higher than controls). Exposure to either pesticide through contact with treated soils did not affect chick survival but altered some biochemical parameters posthatching. Our experiment shows that egg spraying with pesticides should be considered as a relevant exposure scenario in risk assessment procedures, given its potential to affect the reproductive success of ground-nesting farmland birds.