MOF-mediated cascade reaction system for ultrasensitive detection of alkaline phosphatase activity and organophosphorus pesticides.

A metal-organic-framework (MOF) fluorescent sensor is reported based on NH2-MIL-101(Fe) propelled pesticide and alkaline phosphatase (ALP) catalytic reaction. Different from previous reports, a cascade reaction system combined with MOF structural changes to generate fluorescence was employed. The rationale is that ALP can hydrolyze L-ascorbic acid 2-phosphate (AAP) into L-ascorbic acid (AA), which can reduce Fe3+ to decompose structurally NH2-MIL-101(Fe), resulting in 2-aminoterephthalic acid (NH2-BDC) with intense fluorescence. The  fluorescence can be decreased to different degrees due to inhibition of organophosphate pesticides (OPPs) on the activity of ALP. By taking chlorpyrifos (CPY) as the model compound of an OPP pesticide and adding ALP and CPY into the NH2-MIL-101(Fe) framework, the resulting cascade reaction fluorescence sensors exhibit a good sensitivity for CPY and ALP sensing. The working ranges are  0.02-2 µg/L and 0.2-20 mU/mL with detection limits (LOD) of 5.31 ng/L and 0.05 mU/mL, respectively. The proposed sensor has been actually applied to satisfactory detection of CPY and ALP in food and serum samples. This fluorescence-based assay may extend the application of MOF-based biosensors.

Improvement of chlorpyrifos-induced cognitive impairment by mountain grape anthocyanins based on PI3K/Akt signaling pathway.

The organophosphorus insecticide Chlorpyrifos (CPF) is widely used worldwide due to its high effectiveness. However, when ingested through the mouth and nose, it can cause severe neurotoxic effects and cognitive impairment. Natural anthocyanins show great potential in improving cognitive impairment. In this paper, we will delve into the protective effect of anthocyanins on CPF-induced cognitive impairment and its mechanism through the PI3K/Akt signaling pathway. Morris water maze, histopathological, ELISA and western blot analyses showed that anthocyanins effectively ameliorated CPF-induced spatial learning memory impairment in mice by ameliorating CPF-induced AChE inhibition, oxidative stress, and neuroinflammation and by modulating the levels of apoptosis (Caspase-3, Caspase-9) and autophagy (LC3II/ LC3I, Beclin1, p62, mTOR) biomarkers, in order to restore damaged hippocampal tissue morphology, neuron and synapse structures. To identify the action pathway of anthocyanins, we used KEGG and GO pathway enrichment analysis for screening prediction and western blot and molecular docking to verify that anthocyanins improve CPF-induced cognitive impairment by activating the PI3K/Akt pathway.

Maternal exposure to pesticides induces perturbations in the gut microbiota and blood-brain barrier of dams and the progeny, prevented by a prebiotic.

Exposure to pesticide residues during the first 1000 days of life can disrupt body homeostasis and contribute to chronic metabolic diseases. Perinatal chlorpyrifos (CPF) exposure alters gut microbiota (GM) balance, potentially affecting offspring's health. Given the GM influence on brain function, the primary aim is to determine if pesticide-induced dysbiosis (microbial imbalance) affects indirectly other organs, such as the blood-brain barrier (BBB). The secondary objective is to evaluate the prebiotics protective effects, particularly inulin in promoting microbial balance (symbiosis), in both mothers and offspring. A total of 15 or more female rats were divided in 4 groups: control, oral CPF-exposed (1 mg/kg/day), exposed to inulin (10 g/L), and co-exposed to CPF and inulin from pre-gestation until weaning of pups. Samples from intestines, spleen, liver, and brain microvessels underwent microbiological and biomolecular analyses. Bacterial culture assessed GM composition of living bacteria and their translocation to non-intestinal organs. RT qPCR and Western blotting detected gene expression and protein levels of tight junction markers in brain microvessels. CPF exposure caused gut dysbiosis in offspring, with decreased Lactobacillus and Bifidobacterium and increased Escherichia coli (p < 0.01) leading to bacterial translocation to the spleen and liver. CPF also decreased tight junction's gene expression levels (50 to 60% decrease of CLDN3, p < 0.05). In contrast, inulin partially mitigated these adverse effects and restored gene expression to control levels. Our findings demonstrate a causal link between GM alterations and BBB integrity disruptions. The protective effects of inulin suggest potential therapeutic strategies to counteract pesticide-induced dysbiosis.

Eco(geno)toxicity of an acaricidal formulation containing chlorpyrifos, cypermethrin, and fenthion on different plant models and Artemia salina L.

The mixture of pesticides is widely employed in cattle farming to combat ectoparasite resistance, such as ticks. The commercial formulation COLOSSO FC30, which contains three active ingredients (Cypermethrin, Chlorpyrifos, and Fenthion), stands out due to its efficiency. However, animals exposed to this product may become vectors of potentially toxic molecules, possibly causing contamination in aquatic and terrestrial ecosystems. In light of this, this study evaluated the eco(geno)toxic potential of the commercial formulation COLOSSO FC30, using plants (Allium cepa L., Lactuca sativa L., Raphanus sativus L., Pennisetum glaucum L., and Triticum aestivum L.) and Artemia salina L. as model organisms. In the phytotoxicity test, the species were ranked in order of sensitivity to the commercial formulation as follows: P. glaucum > L. sativa > T. aestivum > R. sativus. The most sensitive parameters were root length (RL) and shoot length (SL) of seedlings. In the cytogenotoxicity test with A. cepa, cell division was decreased at concentrations from 0.351 mL L-1 in the meristematic region and root F1. Chromosomal aberrations and micronucleus were observed at all concentrations. In the test with A. salina, the IC50 after 24 h of exposure was 0.01207 mL L-1 of the commercial formulation. The results highlight the need for further research and regulations to understand and minimize the potential environmental impacts of COLOSSO FC30.

Chlorpyrifos induces cytotoxicity via oxidative stress and mitochondrial dysfunction in HepG2 cells.

Chlorpyrifos (CPF), a widely used broad-spectrum organophosphate pesticide, has been associated with various adverse health effects in animals and humans. While its primary mechanism of action involves the irreversible inhibition of acetylcholinesterase, secondary mechanisms have also been suggested. The aim of the present study was to explore the secondary mechanisms of action involved in CPF-induced acute cytotoxicity using human hepatocarcinoma HepG2 cells. In particular, we investigated oxidative stress and mitochondrial function by assessing reactive oxygen species (ROS) generation, lipid peroxidation (LPO) and mitochondrial membrane potential (ΔΨm) alteration. Results showed that 24-h exposure to CPF (78.125-2500 µM) decreased cell viability in a concentration-dependent manner (IC50 = 280.87 ± 26.63 µM). Sub-toxic CPF concentrations (17.5, 35 and 70 µM) induced increases in ROS generation (by 83%), mitochondrial superoxide (by 7.1%), LPO (by 11%), and decreased ΔΨm (by 20%). CPF also upregulated Nrf2 protein expression, indicating the role of the latter in modulating the cellular response to oxidative insults. Overall, our findings suggest that CPF caused hepatotoxicity through oxidative stress and mitochondrial dysfunction. Given the re-emerging use of CPF, this study emphasizes the need for comprehensive analysis to elucidate its toxicity on non-target organs and associated mechanisms.

Lamellar Ti3C2 MXene composite decorated with platinum-doped MoS2 nanosheets as electrochemical sensing functional platform for highly sensitive analysis of organophosphorus pesticides.

Precisely detecting organophosphorus pesticides (OPs) is paramount in upholding human safety and environmental preservation, especially in food safety. Herein, an electrochemical acetylcholinesterase (AChE) sensing platform entrapped in chitosan (Chit) on the glassy carbon electrodes (GCEs) decorated with Pt/MoS2/Ti3C2 MXene (Pt/MoS2/TM) was constructed for the detection of chlorpyrifos. It is worth noting that Pt/MoS2/TM possesses good biocompatibility, remarkable electrical conductivity, environmental stability and large specific surface area. Besides, the heterostructure formed by the composite of TM and MoS2 improves the conductivity and maintains the original structure, which is conducive to improving the electrochemical property. The coordination effect between the individual components enables the even distribution of functional components and enhances the electrochemical performance of the biosensor (AChE-Chit/Pt/MoS2/TM). Under optimal efficiency and sensitivity, the AChE-Chit/Pt/MoS2/TM/GCE sensing platform exerts comparable analytical performance and a wide concentration range of chlorpyrifos from 10-12 to 10-6 M as well as a low limit of detection (4.71 × 10-13 M). Furthermore, the biosensor is utilized to detect OPs concerning three kinds of fruits and vegetables with good feasibility and recoveries (94.81% to 104.0%). This work would provide a new scheme to develop high-sensitivity sensors based on the two-dimensional nanosheet/laminar hybrid structure for practical applications in environmental monitoring and agricultural product detection.

Highly sensitive turn-on electrochemical sensing of organophosphorus pesticides by integration of homogeneous reaction and heterogeneous catalytic signal amplification.

Enzyme-inhibited electrochemical sensor is a promising strategy for detecting organophosphorus pesticides (OPs). However, the poor stability of enzymes and the high oxidation potential of thiocholine signal probe limit their potential applications. To address this issue, an indirect strategy was proposed for highly sensitive and reliable detection of chlorpyrifos by integrating homogeneous reaction and heterogeneous catalysis. In the homogeneous reaction, Hg2+ with low oxidation potential was employed as signal probe for chlorpyrifos detection since its electroactivity can be inhibited by thiocholine, which was the hydrolysate of acetylthiocholine catalyzed by acetylcholinesterase. Additionally, Co,N-doped hollow porous carbon nanocage@carbon nanotubes (Co,N-HPNC@CNT) derived from ZIF-8@ZIF-67 was utilized as high-performance electrode material to amplify the stripping voltammetry signal of Hg2+. Thanks to their synergistic effect, the sensor exhibited outstanding sensing performance, excellent stability and good anti-interference ability. This strategy paves the way for the development of high-performance OP sensors and their application in food safety.

Impact of chlorpyrifos exposure on lung function in Egyptian adolescent agriculture workers.

Chlorpyrifos (CPF) is a widely used organophosphate insecticide that has been linked to detrimental health effects that range from neurological impacts to respiratory disease. The objective of this study was to assess respiratory symptoms associated with CPF exposure throughout the application season. Urine samples were collected from Egyptian adolescent applicators (n = 206) and non-applicators (n = 72) to assess 3,5,6-trichloro-2-pyridinol (TCPy), a biomarker for CPF exposure, along with spirometry measures to determine lung ventilatory function. Samples were collected over 7 months in 2016. Logistic regression was used to model the odds of reporting wheeze symptoms based on urinary TCPy concentrations while controlling for age and smoking in the household. Ordinal multinomial logistic regression was used to model the percent reference for forced expiratory volume in one second (rFEV1) based on urinary TCPy concentration (µg/g creatinine). Wheezing increased with increasing pesticide exposure (OR = 1.74 (1.32 - 2.31)). There was no statistically significant relationship between rFEV1 and TCPy concentration. Efforts to reduce pesticide exposure should be implemented to prevent the potential onset or exacerbation of any linked respiratory complications in adolescents.

Effect of chlorpyrifos on cypermethrin-induced dopaminergic neurotoxicity in rats.

The study aimed to investigate the combined effects of chlorpyrifos and cypermethrin combined on dopaminergic neurotoxicity, motor behaviours and level of selected inflammatory proteins in rats compared to either alone for delineating an interaction between these two pesticides. The rotarod and grip strength tests were employed to assess neurobehavioural changes. The striatal dopamine content and expression of tyrosine hydroxylase (TH), α-synuclein, cyclooxygenase-2 (COX-2), and tumour necrosis factor-α (TNF-α) proteins in the nigrostriatal tissue were measured. Chlorpyrifos impaired the neurobehavioural indexes, reduced the striatal dopamine level, augmented the level of α-synuclein, COX-2, and TNF-α and attenuated the expression of TH similar to but a little less than cypermethrin. Half the dose of both pesticides together produced additional neurotoxicity compared with the usual (highest employed) dose of either alone. The results showed that chlorpyrifos induced moderately less dopaminergic neurotoxicity than cypermethrin. In the combination, they produced a little higher toxicity than either pesticide alone.

Persistent organic pollutants and chlorpyrifos in tissues of a histotrophic viviparous species, the Southern Eagle Ray Myliobatis goodei.

Elasmobranchs are good indicators of marine pollution as they accumulate pollutants from water and food, and occupy different trophic levels. Concentrations of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and chlorpyrifos were quantified in muscle, liver, gonads, gills, and brain in both sexes and maturity stages of the Southern Eagle Ray, Myliobatis goodei, captured in Argentine coastal waters. Moreover, possible histological alterations in the liver and gonads were analyzed. Pollutant concentrations were pervasive across all tissues, with PCBs > OCPs > chlorpyrifos. Elevated pollutant levels were notably found in the liver and gills. We identified thirty-six PCB congeners in tissues, with low-chlorine congeners prevailing. Among OCPs, ∑DDT and ∑endosulfan were predominant. Females exhibited higher pollutant levels in most tissues compared to males, except in the gonads, and adults generally displayed elevated pollutant levels. Histological analysis revealed the presence of atretic follicles and melanomacrophages (MM). Continuous monitoring of pollutant levels, alongside their effects on physiological and ecological traits, is imperative for effective management and conservation efforts.

Microbial detoxification of chlorpyrifos, profenofos, monocrotophos, and dimethoate by a multifaceted rhizospheric Bacillus cereus strain PM38 and its potential for the growth promotion in cotton.

Bacillus genera, especially among rhizobacteria, are known for their ability to promote plant growth and their effectiveness in alleviating several stress conditions. This study aimed to utilize indigenous Bacillus cereus PM38 to degrade four organophosphate pesticides (OPs) such as chlorpyrifos (CP), profenofos (PF), monocrotophos (MCP), and dimethoate (DMT) to mitigate the adverse effects of these pesticides on cotton crop growth. Strain PM38 exhibited distinct characteristics that set it apart from other Bacillus species. These include the production of extracellular enzymes, hydrogen cyanide, exopolysaccharides, Indol-3-acetic acid (166.8 µg/mL), siderophores (47.3 µg/mL), 1-aminocyclopropane-1-carboxylate deaminase activity (32.4 µg/mL), and phosphorus solubilization (162.9 µg/mL), all observed at higher concentrations. This strain has also shown tolerance to salinity (1200 mM), drought (20% PEG-6000), and copper and cadmium (1200 mg/L). The amplification of multi-stress-responsive genes, such as acdS, ituC, czcD, nifH, sfp, and pqqE, further confirmed the plant growth regulation and abiotic stress tolerance capability in strain PM38. Following the high-performance liquid chromatography (HPLC) analysis, the results showed striking compatibility with the first kinetic model. Strain PM38 efficiently degraded CP (98.4%), PF (99.7%), MCP (100%), and DMT (95.5%) at a concentration of 300 ppm over 48 h at 35 °C under optimum pH conditions, showing high coefficients of determination (R2) of 0.974, 0.967, 0.992, and 0.972, respectively. The Fourier transform infrared spectroscopy (FTIR) analysis and the presence of opd, mpd, and opdA genes in the strain PM38 further supported the potential to degrade OPs. In addition, inoculating cotton seedlings with PM38 improved root length under stressful conditions. Inoculation of strain PM38 reduces stress by minimizing proline, thiobarbituric acid-reactive compounds, and electrolyte leakage. The strain PM38 has the potential to be a good multi-stress-tolerant option for a biological pest control agent capable of improving global food security and managing contaminated sites.

Ameliorative potentials of diosmin and hesperidin fractions on chlorpyriphos-induced changes in reproductive hormones, sperm characteristics, and testicular glycogen in male Wistar rats.

Reproductive deficiency is a major outcome of pesticide exposure sequel to cellular oxidative damage to sex organs. Flavonoid possess potent antioxidant capacities to mitigate pesticide related cellular injury. The present investigation examined the mitigative effect of micronized purified fractions of diosmin and hesperidin on reproductive hormones, sperm parameters, and testicular glycogen in male Wistar rats after sub-chronic Chlorpyriphos (CPF) exposure. Twenty-five male Wistar rats (120-145 g) were randomly allocated five rats per group. Group I (DW) received distilled water (2 ml/kg), Group II (S/oil) received soya oil (2 ml/kg), Group III (DAF) received Daflon at 1000 mg/kg, Group IV (CPF) received Chlorpyriphos (7.74 mg/kg), and Group V (DAF + CPF) received Daflon (1000 mg/kg) followed by CPF (7.74 mg/kg) after 30 min of Daflon. This regimen was administered daily for 60 days. After cervical venesection under light chloroform anesthesia, blood samples were examined for levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone. Each rat's testicular tissue was quickly cut, collected, and glycogen evaluated. Sperm concentration, motility, morphology, and viability were measured in the right caudal epididymis. Results revealed that the untreated CPF group had significantly lower FSH, LH, testosterone, testicular glycogen, and sperm concentration. Additionally, CPF group sperm characteristics were abnormal compared to other groups. These reproductive hormones, testicular glycogen, and sperm parameters improved in the Daflon-treated groups. Hence, pre-treatment with flavonoid fractions of diosmin and hesperidin mitigated CPF-induced reproductive toxicity.

Chlorpyrifos induces autophagy by suppressing the mTOR pathway in immortalized GnRH neurons.

Chlorpyrifos (CPF) is a widely used pesticide inducing adverse neurodevelopmental and reproductive effects. However, knowledge of the underlying mechanisms is limited, particularly in the hypothalamus. We investigated the mode of action of CPF at human relevant concentrations (1 nM-100 nM) in immortalized mouse hypothalamic GnRH neurons (GT1-7), an elective model for studying disruption of the hypothalamus-pituitary-gonads (HPG) axis. We firstly examined cell vitality, proliferation, and apoptosis/necrosis. At not-cytotoxic concentrations, we evaluated neuron functionality, gene expression, Transmission Electron Microscopy (TEM) and proteomics profiles, validating results by immunofluorescence and western blotting (WB). CPF decreased cell vitality with a dose-response but did not affect cell proliferation. At 100 nM, CPF inhibited gene expression and secretion of GnRH; in addition, CPF reduced the immunoreactivity of the neuronal marker Map2 in a dose-dependent manner. The gene expression of Estrogen Receptor α and ß (Erα, Erß), Androgen Receptor (Ar), aromatase and oxytocin receptor was induced by CPF with different trends. Functional analysis of differentially expressed proteins identified Autophagy, mTOR signaling and Neutrophil extracellular traps (NETs) formation as significant pathways affected at all concentrations. This finding was phenotypically supported by the TEM analysis, showing marked autophagy and damage of mitochondria, as well as by protein analysis demonstrating a dose-dependent decrease of mTOR and its direct target pUlk1 (Ser 757). The bioinformatics network analysis identified a core module of interacting proteins, including Erα, Ar, mTOR and Sirt1, whose down-regulation was confirmed by WB analysis. Overall, our results demonstrate that CPF is an inhibitor of the mTOR pathway leading to autophagy in GnRH neurons; a possible involvement of the Erα/Ar signaling is also suggested. The evidence for adverse effects of CPF in the hypothalamus in the nanomolar range, as occurs in human exposure, increases concern on potential adverse outcomes induced by this pesticide on the HPG axis.

Triple negative breast cancer cells exposed to aryl hydrocarbon receptor ligands hexachlorobenzene and chlorpyrifos activate endothelial cells.

Breast cancer is currently one of the most prevalent cancers worldwide. The mechanisms by which pesticides can increase breast cancer risk are multiple and complex. We have previously observed that two aryl hydrocarbon receptor (AhR) agonists ‒pesticides hexachlorobenzene (HCB) and chlorpyrifos (CPF)‒ act on tumor progression, stimulating cell migration and invasion in vitro and tumor growth in animal models. Elevated levels of hypoxia inducible factor-1α (HIF-1α) are found in malignant breast tumors, and HIF-1α is known to induce proangiogenic factors such as vascular endothelial growth factor (VEGF), nitric oxide synthase-2 (NOS-2) and cyclooxygenase-2 (COX-2), which are fundamental in breast cancer progression. In this work, we studied HCB (0.005, 0.05, 0.5 and 5 µM) and CPF (0.05, 0.5, 5 and 50 µM) action on the expression of these proangiogenic factors in triple negative breast cancer cells MDA-MB-231, as well as the effect of their conditioned medium (CM) on endothelial cells. Exposure to pesticides increased HIF-1α and VEGF protein expression in an AhR-dependent manner. In addition, HCB and CPF boosted NOS-2 and COX-2 content and VEGF secretion in MDA-MB-231 cells. The treatment of endothelial cells with CM from tumor cells exposed to pesticides increased cell proliferation, migration, and tubule formation, enhancing both tubule length and branching points. Of note, these effects were VEGF-dependent, as they were blocked in the presence of a VEGF receptor-2 (VEGFR-2) inhibitor. In sum, our results highlight the harmful impact of HCB and CPF in modulating the interaction between breast cancer and endothelial cells and promoting angiogenesis.

Pesticides in water and sediments from natural protected areas of Spain and their associated ecological risk.

In the last years, issues related to intensive agriculture have been found in protected areas potentially harming wildlife. This study aimed to analyze a wide range of pesticides in water and sediments of two protected areas namely Doñana Natural Park (DNP) and Tablas de Daimiel National Park (TDNP) performing an environmental risk assessment in order to highlight potential risks to living organisms derived from pesticide burden. Higher pesticide load was found in DNP than TDNP with similar distribution profiles, with pyrethroid insecticides (PYRs) the main detected class. Particularly problematic are two PYRs, cyhalothrin and fenvalerate, which were detected at high concentrations that can pose a high risk to aquatic organisms. In addition, despite being detected at lower concentrations, the presence of chlorpyrifos, cypermethrin, and permethrin in water, and of chlorpyrifos, dicofol, and diflufenican in sediments, must be taken into account due to their potential risks for aquatic organisms. Moreover, some banned pesticides such as dimethoate, terbutryn, diazinon, and tricyclazol were detected in water at levels which deserve further investigation to assess their potential sources, including potential illegal practices.

Effects of acute toxicity of the pesticide Chlorpyrifos and the metal Cadmium, both individually and in mixtures, on two species of native neotropical cladocerans.

The excessive use of pesticides in agriculture and the widespread use of metals in industrial activities and or technological applications has significantly increased the concentrations of these pollutants in both aquatic and terrestrial ecosystems worldwide, making aquatic biota increasingly vulnerable and putting many species at risk of extinction. Most aquatic habitats receive pollutants from various anthropogenic actions, leading to interactions between compounds that make them even more toxic. The aim of this study was to assess the effects of the compounds Chlorpyrifos (insecticide) and Cadmium (metal), both individually and in mixtures, on the cladocerans Ceriodaphnia rigaudi and Ceriodaphnia silvestrii. Acute toxicity tests were conducted for the compounds individually and in mixture, and an ecological risk assessment (ERA) was performed for both compounds. Acute toxicity tests with Cadmium resulted in EC50-48 h of 0.020 mg L-1 for C. rigaudi and 0.026 mg L-1 for C. silvestrii, while tests with Chlorpyrifos resulted in EC50-48 h of 0.047 µg L-1 and 0.062 µg L-1, respectively. The mixture test for C. rigaudi showed the occurrence of additive effects, while for C. silvestrii, antagonistic effects occurred depending on the dose level. The species sensitivity distribution curve for crustaceans, rotifers, amphibians, and fishes resulted in an HC5 of 3.13 and an HC50 of 124.7 mg L-1 for Cadmium; an HC5 of 9.96 and an HC50 of 5.71 µg L-1 for Chlorpyrifos. Regarding the ERA values, Cadmium represented a high risk, while Chlorpyrifos represented an insignificant to a high risk.

Vitamin E alleviates chlorpyrifos induced glutathione depletion, lipid peroxidation and iron accumulation to inhibit ferroptosis in hepatocytes and mitigate toxicity in zebrafish.

Organophosphates, a widely used group of pesticides, can cause severe toxicity in human beings and other non-target organisms. Liver, being the primary site for xenobiotic metabolism, is extremely vulnerable to xenobiotic-induced toxicity. Considering the numerous vital functions performed by the liver, including xenobiotic detoxification, protecting this organ from the ubiquitous pesticides in our food and environment is essential for maintaining homeostasis. In this study, we have investigated the impact of the organophosphate pesticide, Chlorpyrifos (CPF), on zebrafish liver at a concentration (300 µg/L) which is environmentally realistic. We have also demonstrated the role of dietary supplementation of α-tocopherol or Vitamin E (Vit E) (500 mg/kg feed) in mitigating pesticide-induced liver toxicity. Mechanistically, we showed that Vit E resulted in significant elevation of the Nrf2 and its downstream antioxidant enzyme activities and gene expressions, especially that of GST and GPx, resulting in reduction of CPF-induced intracellular lipid ROS and hepatic LPO. Further interrogation, such as analysis of GSH: GSSG ratio, intracellular iron concentration, iron metabolizing genes, mitochondrial dysfunction etc. revealed that CPF induces ferroptosis which can be reversed by Vit E supplementation. Ultimately, reduced concentration of CPF in zebrafish serum and flesh highlighted the role of Vit E in ameliorating CPF toxicity.

Chlorpyrifos-induced suppression of the antioxidative defense system leads to cytotoxicity and genotoxicity in macrophages.

Chlorpyrifos, widely used for pest control, is known to have various harmful effects, although its toxic effects in macrophages and the mechanisms underlying its toxicity remain unclear. The present study investigated the toxic effects of chlorypyrifos in a macrophage cell line. Here, we found that chlorpyrifos induced cytotoxicity and genotoxicity in RAW264.7 macrophages. Moreover, chlorpyrifos induced intracellular ROS production, subsequently leading to lipid peroxidation. Chlorpyrifos reduced the activation of antioxidative enzymes including superoxide dismutase, catalase, and glutathione peroxidase. Chlorpyrifos upregulated HO-1 expression and activated the Keap1-Nrf2 pathway, as indicated by enhanced Nrf2 phosphorylation and Keap1 degradation. Chlorpyrifos exerted effects on the following in a dose-dependent manner: cytotoxicity, genotoxicity, lipid peroxidation, intracellular ROS production, antioxidative enzyme activity reduction, HO-1 expression, Nrf2 phosphorylation, and Keap1 degradation. Notably, N-acetyl-L-cysteine successfully inhibited chlorpyrifos-induced intracellular ROS generation, cytotoxicity, and genotoxicity. Thus, chlorpyrifos may induce cytotoxicity and genotoxicity by promoting intracellular ROS production and suppressing the antioxidative defense system activation in macrophages.

Chlorella vulgaris algae ameliorates chlorpyrifos toxicity in Nile tilapia with special reference to antioxidant enzymes and Streptococcus agalactiae infection.

BACKGROUND: Chlorpyrifos (CPF) is a widely used pesticide in the production of plant crops. Despite rapid CPF biodegradation, fish were exposed to wastewater containing detectable residues. Recently, medicinal plants and algae were intensively used in aquaculture to replace antibiotics and ameliorate stress impacts. METHODS AND RESULTS: An indoor experiment was conducted to evaluate the deleterious impacts of CPF pollution on Nile tilapia health and the potential mitigation role of Chlorella vulgaris algae. Firstly, the median lethal concentration LC50 - 72 h of CPF was determined to be 85.8 µg /L in Nile tilapia (35.6 ± 0.5 g body weight) at a water temperature of 27.5 °C. Secondly, fish were exposed to 10% of LC50 - 72 h for six weeks, and tissue samples were collected and examined every two weeks. Also, Nile tilapia were experimentally infected with Streptococcus agalactiae. Exposed fish were immunosuppressed expressed with a decrease in gene expressions of interleukin (IL) 1ß, IL-10, and tumor necrosis factor (TNF)-α. Also, a decline was recorded in glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) gene expression in the head kidney tissue. A high mortality rate (MR) of 100% was recorded in fish exposed to CPF for six weeks and challenged with S. agalactiae. Fish that received dietary C. vulgaris could restore gene expression cytokines and antioxidants compared to the control. After six weeks of CPF exposure, fish suffered from anemia as red blood cell count (RBCs), hemoglobin (Hb), and packed cell volume (PCV) significantly declined along with downregulation of serum total protein (TP), globulin (GLO), and albumin (ALB). Liver enzymes were significantly upregulated in fish exposed to CPF pollution, alanine aminotransferase (ALT) (42.5, 53.3, and 61.7 IU/L) and aspartate aminotransferase (AST) (30.1, 31.2, and 22.8) after 2, 4, and 6 weeks, respectively. On S. agalactiae challenge, high MR was recorded in Nile tilapia exposed to CPF (G3) 60%, 60%, and 100% in week 2, week 4, and week 6, and C. vulgaris provided a relative protection level (RPL) of 0, 14.29, and 20%, respectively. CONCLUSIONS: It was concluded that CPF pollution induces immunosuppressed status, oxidative stress, and anemic signs in Nile tilapia. In contrast, C. vulgaris at a 50 g/kg fish feed dose could partially ameliorate such withdrawals, restoring normal physiological parameters.

Molecular docking analysis of chlorpyrifos at the human α7-nAChR and its potential relationship with neurocytoxicity in SH-SY5Y cells.

The organophosphate insecticide chlorpyrifos (CPF), an acetylcholinesterase inhibitor, has raised serious concerns about human safety. Apart from inducing synaptic acetylcholine accumulation, CPF could also act at nicotinic acetylcholine receptors, like the α7-isoform (α7-nAChR), which could potentially be harmful to developing brains. Our aims were to use molecular docking to assess the binding interactions between CPF and α7-nAChR through, to test the neurocytotoxic and oxidative effects of very low concentrations of CPF on SH-SY5Y cells, and to hypothesize about the potential mediation of α7-nAChR. Docking analysis showed a significant binding affinity of CPH for the E fragment of the α7-nAChR (ΔGibbs: -5.63 to -6.85 Kcal/mol). According to the MTT- and Trypan Blue-based viability assays, commercial CPF showed concentration- and time-dependent neurotoxic effects at a concentration range (2.5-20 µM), ten-folds lower than those reported to have crucial effects for sheer CPF. A rise of the production of radical oxygen species (ROS) was seen at even lower concentrations (1-2.5 µM) of CPF after 24h. Notably, our docking analysis supports the antagonistic actions of CPF on α7-nAChR that were recently published. In conclusion, while α7-nAChR is responsible for neuronal survival and neurodevelopmental processes, its activity may also mediate the neurotoxicity of CPF.