Paraquat induces redox imbalance and disrupts glutamate and energy metabolism in the hippocampus of prepubertal rats

Redox imbalance and inflammation: A link to depression risk in brazilian pesticide-exposed farmers

This study aims to elucidate the mechanisms linking occupational pesticide exposure to depression among rural workers from Maravilha, Brazil. We assessed the mental health, oxidative, and inflammatory profiles of farmers exposed to pesticides (N = 28) and compared them to an urban control group without occupational exposure to pesticides (N = 25). Data on sociodemographic, occupational history, and clinical records were collected. Emotional states were evaluated using the State-Trait Anxiety Inventory (STAI) and Beck Depression Inventory (BDI). Biochemical, hematological, inflammatory, and redox parameters were examined in blood samples from both groups. Results showed educational disparities between groups and unveiled a concerning underutilization of personal protective equipment (PPEs) among farmers. Glyphosate was the predominant pesticide used by farmers. Farmers exhibited higher BDI scores, including more severe cases of depression. Additionally, elevated levels of creatinine, ALT, AST, and LDH were observed in farmers, suggesting potential renal and hepatic issues due to pesticide exposure. Oxidative stress markers, such as increased lipid peroxidation and superoxide dismutase (SOD) activity, along with decreased catalase (CAT) activity and ascorbic acid levels, were noted in the pesticide-exposed group compared to controls. Elevated levels of inflammatory cytokines, particularly IL-1β, IL-6 and TNF-α, were also observed in pesticide-exposed group. Our findings suggest that inflammation, oxidative distress and lower educational levels may be associated with depression in pesticide-exposed farmers. This study highlights the impact of occupational pesticide exposure on the mental health of rural workers. The underuse of PPEs and the link between depressive symptoms, inflammation, and oxidative stress underscore the urgent need for improved safety measures in agricultural practices. Addressing these issues will contribute to a deeper understanding of the intricate relationship between environmental exposures and mental health outcomes.

Glyphosate-induced glioblastoma cell proliferation: Unraveling the interplay of oxidative, inflammatory, proliferative, and survival signaling pathways

The aim of the present study was to investigate the impacts of glyphosate herbicide on the survival and proliferation of glioblastoma cells and to explore the molecular mechanisms underlying such effects. For this, cultured human glioblastoma cell line, A172, was exposed to the glyphosate analytical standard, a glyphosate-based herbicide formulation (GBH), or the metabolite aminomethylphosphonic acid (AMPA). The three compounds induced A172 cytotoxicity after 24 h of exposure, with more prominent cytotoxic effects after 48 and 72 h of treatment. Further experiments were performed by treating A172 cells for 6 h with glyphosate, GBH, or AMPA at 0.5 mg/L, which corresponds to the maximum residue limits for glyphosate and AMPA in drinking water in Brazil. Colony forming units (CFU) assay showed that AMPA increased the number of CFU formed, while glyphosate and GBH increased the CFU sizes. The three compounds tested altered the cell cycle and caused DNA damage, as indicated by the increase in γ-H2AX. The mechanisms underlying the pesticide effects involve the activation of Akt and mitogen-activated protein kinases (MAPKs) signaling pathways, oxidative imbalance, and inflammation. Glyphosate led to NLRP3 activation culminating in caspase-1 recruitment, while AMPA decreased NLRP3 immunocontent and GBH did not alter this pathway. Results of the present study suggest that exposure to glyphosate (isolated or in formulation) or to its metabolite AMPA may affect cell signaling pathways resulting in oxidative damage and inflammation, giving glioblastoma cells an advantage by increasing their proliferation and growth.

Could pesticide exposure be implicated in the high incidence rates of depression, anxiety and suicide in farmers? A systematic review

Pesticide exposure and poisoning may rise the risk of mental health problems and suicidal tendencies. To explore the potential connection between chronic occupational exposure to pesticides and depression, anxiety, and suicide-related outcomes in farmers, a systematic review was performed. Systematic review protocol is available in PROSPERO registration number CRD42022316285. A total of fifty-seven studies met inclusion criteria: twenty-nine on depression or other mental disorders, twelve on suicide (two of them on both depression and suicide), and fourteen on pesticide poisoning or self-poisoning and death. Among the fifty-seven selected studies, eighteen were conducted in Asia, seventeen in North America, fourteen in South America, seven in European Union, one in Africa, and one in Australia/Oceania. Selected studies demonstrated an increased prevalence of depressive disorders in farmworkers exposed to pesticides as well as an increased self-reported prevalence of depression in this population. Moreover, previous pesticide poisoning increased the risk estimates for depression or other mental disorders as compared with chronic pesticide exposure. Severe pesticide poisoning and multiple poisoning showed increased risks of depressive symptoms compared with milder cases. In addition, financial difficulties and poor health were positively correlated with depression. Among studies on suicide, nine of them found that suicide rates increased in areas devoted to agriculture with intensive pesticide consumption. Moreover, studies demonstrate a higher suicide risk among farmers. The present review suggests more attention to the farmer's mental health and more detailed studies on occupational exposure to the mixture of these compounds.

Paraquat exposure induces Parkinsonism by altering lipid profile and evoking neuroinflammation in the midbrain

Paraquat (PQ) is the most widely used herbicide in the world and a well-known potent neurotoxin for humans. PQ exposure has been linked to increase the risk of Parkinson's disease (PD). However, the mechanism underlying its neurotoxic effects in PD pathogenesis is unclear. In our present study, C57BL/6J mice treated with PQ manifested severe motor deficits indicated by the significant reductions in suspension score, latency to fall from rotarod, and grip strength at 8 weeks after PQ exposure. Pathological hallmarks of Parkinsonism in the midbrain such as dopaminergic neuron loss, increased α-synuclein protein, and dysregulated PD-related genes were observed. Non-targeted lipidome analysis demonstrated that PQ exposure alters lipid profile and abundance, increases pro-inflammatory lipids.27 significantly altered subclasses of lipids belonged to 6 different lipid categories. Glycerophospholipids, sphingolipids, and glycerides were the most abundant lipids. Abundance of pro-inflammatory lipids such as Cer, LPC, LPS, and LPI was significantly increased in the midbrain. mRNA expressions of genes regulating ceramide biosynthesis in the midbrain were markedly up-regulated. Moreover, PQ exposure increased serum pro-inflammatory cytokines and provoked neuroinflammation in the midbrain. Pro-inflammatory lipids and cytokines in the midbrain were positively correlated with motor deficits. PQ poisoning in humans significantly also elevated serum pro-inflammatory cytokines and induced an intense systemic inflammation. In summary, we presented initial investigations of PQ induced molecular events related to the PD pathogenesis, capturing aspects of disturbed lipid metabolism, neuroinflammation, impairment of dopaminergic neurons in the midbrain, and an intense systemic inflammation. These neurotoxic effects of PQ exposure may mechanistically contribute to the pathogenesis of PQ induced Parkinsonism. Results of this study also strongly support the hypothesis that ever-increasing prevalence of Parkinson's disease is etiologically linked to the health risk of exposure to neurotoxic environmental pollutants.

Perinatal exposure to a glyphosate pesticide formulation induces offspring liver damage

The present study investigated the effects of perinatal exposure to glyphosate-based herbicide (GBH) in offspring's liver. Pregnant Wistar rats were exposed to GBH (70 mg glyphosate/Kg body weight/day) in drinking water from gestation day 5 to postnatal day 15. The perinatal exposure to GBH increased ⁴⁵Ca²⁺ influx in offspring's liver. Pharmacological tools indicated a role played by oxidative stress, phospholipase C (PLC) and Akt pathways, as well as voltage-dependent Ca²⁺ channel modulation on GBH-induced Ca²⁺ influx in offspring's liver. In addition, changes in the enzymatic antioxidant defense system, decreased GSH content, lipid peroxidation and protein carbonylation suggest a connection between GBH-induced hepatotoxic mechanism and redox imbalance. The perinatal exposure to GBH also increased the enzymatic activities of transaminases and gamma-glutamyl transferase in offspring's liver and blood, suggesting a pesticide-induced liver injury. Moreover, we detected increased iron levels in liver, blood and bone marrow of GBH-exposed rats, which were accompanied by increased transferrin saturation and decreased transferrin levels in blood. The levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were increased in the liver of rats perinatally exposed to GBH, which were associated with. Increased phospho-p65NFκB immunocontent. Therefore, we propose that excessive amounts of iron in offspring's liver, blood and bone marrow induced by perinatal exposure to GBH may account for iron-driven hepatotoxicity, which was associated with Ca²⁺ influx, oxidative damage and inflammation. Further studies will clarify whether these events can ultimately impact on liver function.