Lung inflammation from repeated exposure to LPS and glyphosate

Overview of human health effects related to glyphosate exposure

Glyphosate is a chemical compound derived from glycine, marketed as a broad-spectrum herbicide, and represents one of the most widely used pesticides in the world. For a long time, it was assumed that glyphosate was harmless, either due to its selective enzymatic acting method on plants, and because commercial formulations were believed to contain only inert chemicals. Glyphosate is widely spread in the environment, the general population is daily exposed to it via different routes, including the consumption of both plant, and non-plant based foods. Glyphosate has been detected in high amounts in workers' urine, but has been detected likewise in bodily fluids, such as blood and maternal milk, and also in 60%-80% of general population, including children. Considering its massive presence, daily exposure to glyphosate could be considered a health risk for humans. Indeed, in 2015, the IARC (International Agency for Research on Cancer) classified glyphosate and its derivatives in Group 2A, as probable human carcinogens. In 2022, nevertheless, EFSA (European Food Safety Authority) stated that the available data did not provide sufficient evidence to prove the mutagenic/carcinogenic effects of glyphosate. Therefore, the European Commission (EC) decided to renew the approval of glyphosate for another 10 years. The purpose of this review is to examine the scientific literature, focusing on potential risks to human health arising from exposure to glyphosate, its metabolites and its commercial products (e.g., Roundup®), with particular regard to its mutagenic and carcinogenic potential and its effects as endocrine disrupter (ED) especially in the human reproductive system.

In vitro immunotoxicity effects of carbendazim were inhibited by n-acetylcysteine in microglial BV-2 cells

Carbendazim (CBZ) is a benzimidazole fungicide widely used worldwide in industrial, agricultural, and veterinary practices. Although, CBZ was found in all brain tissues causing serious neurotoxicity, its impact on brain immune cells remain scarcely understood. Our study investigated the in vitro effects of CBZ on activated microglial BV-2 cells. Lipopolysaccharide (LPS)-stimulated BV-2 cells were exposed to increasing concentrations of CBZ and cytokine release was measured by ELISA, and Cytometric Bead Array (CBA) assays. Mitochondrial superoxide anion (O2·-) generation was evaluated by Dihydroethidium (DHE) and nitric oxide (NO) was assessed by Griess reagent. Lipid peroxidation was evaluated by measuring the malonaldehyde (MDA) levels. The transmembrane mitochondrial potential (ΔΨm) was detected by cytometry analysis with dihexyloxacarbocyanine iodide (DiOC6(3)) assay. CBZ concentration-dependently increased IL-1β, IL-6, TNF-α and MCP-1 by LPS-activated BV-2 cells. CBZ significantly promoted oxidative stress by increasing NO, O2·- generation, and MDA levels. In contrast, CBZ significantly decreased ΔΨm. Pre-treatment of BV-2 cells with N-acetylcysteine (NAC) reversed all the above mentioned immunotoxic parameters, suggesting a potential protective role of NAC against CBZ-induced immunotoxicity via its antioxidant and anti-inflammatory effects on activated BV-2 cells. Therefore, microglial proinflammatory over-activation by CBZ may be a potential mechanism by which CBZ could induce neurotoxicity and neurodegenerative disorders.

In Vitro Effects of Cypermethrin and Glyphosate on LPS-Induced Immune Cell Activation

(1) Background: The insecticide cypermethrin (Cypm) and the herbicide glyphosate (Glyp) are among the most widely used pesticides. While the two pesticides have been considered to have low toxicity in mammals, some indication of potential immunotoxicity has emerged. The aim of this work was to investigate in vitro the effects of Cypm and Glyp on bacteria lipopolysaccharide (LPS)-induced immune cell activation and of Cypm on 2-mercaptobenzothiazole (MBT)-induced maturation of dendritic cells (DCs). (2) Methods: The release of the inflammatory cytokines TNF-α and IL-8, the expression of the surface markers CD54 and CD86 in human primary peripheral blood mononuclear cells (PBMC), and THP-1 cells were investigated together with CD83, HLA-DR, IL-6, and IL-18 in DCs. (3) Results: While no significant modulation on LPS-induced immune cell activation was observed following Glyp exposure, with only a trend toward an increase at the highest concentration tested, Cypm reduced the responses to LPS and to MBT, supporting a direct immunosuppressive effect. Overall, the present study contributes to our understanding of pesticide-induced immunotoxicity, and the results obtained support evidence showing the immunosuppressive effects of Cypm.

Glyphosate and environmental toxicity with "One Health" approach, a review

The herbicide Glyphosate (GLY), or N-(phosphonomethyl) glycine was synthesized in 1950 and applied to control weeds in agricultural production. For a long time, it was believed that it was an inert compound, but many studies have instead demonstrated over the years the dangers of GLY to the ecosystem and human health. Among the best-known effects, it is known that GLY interferes with the metabolic pathways of plants and the main groups of microorganisms, negatively influencing their growth. GLY interferes with the metabolic pathways of plants and major groups of microorganisms negatively affecting their growth. The extensive GLY application on fields results in a "slow death" of plants through the minor resistance to root pathogens and in increasing pollution of freshwaters and soils. Unfortunately, however, unlike the old beliefs, GLY can reach non-target destinations, in this regard, ecological studies and environmental epidemiology are of significant interest. In this review, we focus on the effects of acute and chronic exposure to GLY on the health of plants, animals, and humans from a One Health perspective. GLY has been linked to neurological and endocrine issues in both humans and animals, and behavioral modification on specific bioindicators, but the knowledge about the ratio cause-and-effect still needs to be better understood and elucidated. Environmental GLY residues analysis and policy acts will both require new criteria to protect environmental and human health.

Adhesion Molecules in Lung Inflammation from Repeated Glyphosate Exposures

Glyphosate is an active ingredient in herbicides. Exposure to glyphosate-based herbicides has been associated with respiratory dysfunctions in agricultural workers. The ability of inhaled glyphosate to induce lung inflammation is not well understood. Further, the role of adhesion molecules in glyphosate-induced lung inflammation has not been studied. We evaluated lung inflammatory responses from single and repeated glyphosate exposures. Male C57BL/6 mice were intranasally exposed to glyphosate (1 μg/40 μL) for 1 day or once daily for 5 days or 10 days. Lung tissue and bronchoalveolar lavage (BAL) fluid were collected and analyzed. Repeated exposure to glyphosate for 5 days and 10 days resulted in an increase in neutrophils in BAL fluid and higher eosinophil peroxidase levels in lungs, with leukocyte infiltration further confirmed through lung histology. Repetitive exposure to glyphosate increased IL-33 and Th2 cytokines IL-5 and IL-13. A single glyphosate treatment revealed expression for ICAM-1, VCAM-1, and vWF adhesion molecules in the perivascular region of lung sections; with repeated treatment (5 and 10 days), adhesion molecule expression was found in the perivascular, peribronchiolar, and alveolar regions of the lungs. Repetitive exposure to glyphosate induced cellular inflammation in which adhesion molecules may be important to the lung inflammatory process.

Single-cell transcriptome analysis reveals liver injury induced by glyphosate in mice

BACKGROUND

Glyphosate (GLY), as the active ingredient of the most widely used herbicide worldwide, is commonly detected in the environment and living organisms, including humans. Its toxicity and carcinogenicity in mammals remain controversial. Several studies have demonstrated the hepatotoxicity of GLY; however, the underlying cellular and molecular mechanisms are still largely unknown.

METHODS

Using single-cell RNA sequencing (scRNA-seq), immunofluorescent staining, and in vivo animal studies, we analyzed the liver tissues from untreated and GLY-treated mice.

RESULTS

We generated the first scRNA-seq atlas of GLY-exposed mouse liver. GLY induced varied cell composition, shared or cell-type-specific transcriptional alterations, and dysregulated cell-cell communication and thus exerted hepatotoxicity effects. The oxidative stress and inflammatory response were commonly upregulated in several cell types. We also observed activation and upregulated phagocytosis in macrophages, as well as proliferation and extracellular matrix overproduction in hepatic stellate cells.

CONCLUSIONS

Our study provides a comprehensive single-cell transcriptional picture of the toxic effect of GLY in the liver, which offers novel insights into the molecular mechanisms of the GLY-associated hepatotoxicity.

Glyphosate differentially affects the allergic immune response across generations in mice

Exposure to environmental pollutants via food, particularly during the prenatal and early postnatal periods, has been linked to adverse effects on the immune system. Among these pollutants, the widely used pesticide glyphosate has been associated with endocrine disruption, autism, and cancer. Occupational high exposure to glyphosate has also been shown to influence immune function and exacerbate allergic asthma. However, there are no studies investigating the effect of a common low-dose glyphosate exposure on the allergic immune response - neither directly nor across generations. We therefore explored the impact of oral low-dose glyphosate exposure (0.5 and 50 mg/kg body weight/day) on airway inflammation in dams (F0) and the offspring (F1 and F2 generations) using a murine multi-generational asthma model. While exposure to 50 mg/kg glyphosate induced a mild eosinophilic infiltration in the bronchoalveolar lavage and T_H2 cytokine production in the dams, the F1 offspring developed a reduced immune response after maternal exposure to 0.5 mg/kg glyphosate. In particular, decreased lung inflammation, HDM-specific IgE levels, and asthma-relevant cytokine production were primarily observed in the female F1 offspring. However, not only the T_H2 cytokines IL-13 and IL-5 but also the T_H17 cytokine IL-17 and T_H1 cytokine IFN-γ were reduced indicating a more general immunosuppressive function. Notably, the dampened immune response was no longer observed in the female F2 generation. Furthermore, female F1 offspring showed an increased abundance of bacteria in the gut, which have been associated with probiotic-mediated reduced allergic immune responses. Our results suggest a potential immunosuppressive effect of low-dose maternal glyphosate exposure in the F1 offspring that might be mediated by an altered microbiota composition. Further studies are needed to explore if this type of immune response modulation might also be associated with impairments in immune defense upon infectious diseases or even cancer pathology.

Prenatal pyrethroid exposure and lung function among school-aged children

BACKGROUND

Previous epidemiological evidence mainly focused on the adverse effects of prenatal exposure to pyrethroid insecticides (PYRs) on respiratory health during childhood. It remains unclear whether the PYR exposures can also impact on children's lung function.

OBJECTIVES

To explore the potential effects of prenatal PYR exposures on lung function in a population of Chinese children.

METHODS

This study included 233 mother-child dyads from the Laizhou Wan Birth Cohort (LWBC), Shandong province, northern China, between September 2010 and December 2013. Three metabolites of PYRs [3-phenoxybenzoic acid (3-PBA), and cis- and trans-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (cis-DCCA and trans-DCCA)] were measured using gas chromatography-mass spectrometry (GC-MS) in maternal urine samples collected at recruitment. Lung function was assessed with spirometry in children aged 6-8 years. Multivariable linear regression and generalized linear models (GLMs) assessed the associations of prenatal PYR exposures with lung function in children.

RESULTS

Among the PYR metabolites, 3-PBA (81.5%) were most frequently detected, followed by trans-DCCA (55.4%) and cis-DCCA (21.9%). The 3-PBA concentration was associated with a 1% decrease in FEV₁/FVC in the highest quartiles of exposure compared to the lowest quartile, with a potential dose response association (p-trend = 0.085). Our findings provide a suggestive effect modification by sex, with girls being more susceptible than the boys (p-trend = 0.011). However, there were no associations between the trans-DCCA concentration and lung function parameters.

CONCLUSION

Prenatal 3-PBA concentrations were associated with a modest decrease in FEV₁/FVC among school-aged children, and the association was slightly more pronounced for the girls than for the boys.