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Environmental Research May 2024Pesticide exposure has been linked to some autoimmune diseases and colorectal cancer, possibly via alteration of gut microbiota or other mechanisms. While pesticides...
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.
Topics: Humans; Male; Pesticides; Middle Aged; Female; Occupational Exposure; Inflammatory Bowel Diseases; Spouses; Adult; Aged; Farmers; Incidence; Iowa; Agriculture
PubMed: 38354883
DOI: 10.1016/j.envres.2024.118464 -
The Journal of Physical Chemistry. B Jun 2024Methyl-parathion hydrolase (MPH), which evolved from dihydrocoumarin hydrolase, offers one of the most efficient enzymes for the hydrolysis of methyl-parathion....
Methyl-parathion hydrolase (MPH), which evolved from dihydrocoumarin hydrolase, offers one of the most efficient enzymes for the hydrolysis of methyl-parathion. Interestingly, the substrate preference of MPH shifts from the methyl-parathion to the lactone dihydrocoumarin (DHC) after its mutation of five specific residues (R72L, L273F, L258H, T271I, and S193Δ, m5-MPH). Here, extensive QM/MM calculations and MM MD simulations have been used to delve into the structure-function relationship of MPH enzymes and plausible mechanisms for the chemical and nonchemical steps, including the transportation and binding of the substrate DHC to the active site, the hydrolysis reaction, and the product release. The results reveal that the five mutations remodel the active pocket and reposition DHC within the active site, leading to stronger enzyme-substrate interactions. The MM/GBSA-estimated binding free energies are about -20.7 kcal/mol for m5-MPH and -17.1 kcal/mol for wild-type MPH. Furthermore, this conformational adjustment of the protein may facilitate the chemical step of DHC hydrolysis and the product release, although there is a certain influence on the substrate transport. The hydrolytic reaction begins with the nucleophilic attack of the bridging OH with the energy barriers of 22.0 and 18.0 kcal/mol for the wild-type and m5-MPH enzymes, respectively, which is rate-determining for the entire process. Unraveling these mechanistic intricacies may help in the understanding of the natural evolution of enzymes for diverse substrates and establish the enzyme structure-function relationship.
Topics: Molecular Dynamics Simulation; Coumarins; Quantum Theory; Hydrolysis; Catalytic Domain; Substrate Specificity; Thermodynamics; Hydrolases
PubMed: 38814729
DOI: 10.1021/acs.jpcb.4c00970 -
Toxicology in Vitro : An International... May 2024Organophosphorus compounds (OP) constitute a large group of chemicals including pesticides and nerve agents. Organothiophosphate pesticides require cytochrome...
Organophosphorus compounds (OP) constitute a large group of chemicals including pesticides and nerve agents. Organothiophosphate pesticides require cytochrome P450-mediated oxidative desulphuration in the liver to form corresponding oxons, which are potent inhibitors of the enzyme acetylcholinesterase (AChE). Human HepaRG cells are a promising tool to study liver-specific functions and have been shown to maintain drug metabolizing enzymes. This research describes for the first time the in vitro metabolic activation of an organothiophosphate to its active oxon by two different HepaRG cell-based models. Monolayer cultures and liver spheroids were exposed to the model OP parathion and the quantification of the corresponding oxon was performed with an AChE inhibition assay. Our results showed a time- and dose-dependent cytochrome P450 catalyzed bioactivation and a superior metabolism capacity of the monolayer HepaRG model in comparison with the liver spheroids. Finally, HepaRG cells can be assessed as a metabolically competent cell model intermediate between cell-free preparations and intact animals and as suitable to study OP metabolism in the human liver.
Topics: Animals; Humans; Parathion; Pesticides; Acetylcholinesterase; Liver; Cytochrome P-450 Enzyme System
PubMed: 38521251
DOI: 10.1016/j.tiv.2024.105811 -
Molecules (Basel, Switzerland) Nov 2023An unprecedented photocatalyst, SmEuSbO, was successfully fabricated in this paper, through a high-temperature solid-state calcination method, which represented its...
An unprecedented photocatalyst, SmEuSbO, was successfully fabricated in this paper, through a high-temperature solid-state calcination method, which represented its first ever synthesis. Additionally, using the solvothermal method, the SmEuSbO/ZnBiSbO heterojunction photocatalyst (SZHP) was fabricated, marking its debut in this study. XRD analysis confirmed that both SmEuSbO and ZnBiSbO exhibited pyrochlore-type crystal structures with a cubic lattice, belonging to the Fd3m space group. The crystal cell parameter was determined to be 10.5682 Å or 10.2943 Å for SmEuSbO or ZnBiSbO, respectively. The band gap width measured for SmEuSbO or ZnBiSbO was 2.73 eV or 2.61 eV, respectively. Under visible light irradiation for 150 min (VLTI-150 min), SZHP exhibited remarkable photocatalytic activity, achieving 100% removal of parathion methyl (PM) concentration and 99.45% removal of total organic carbon (TOC) concentration. The kinetic constant () for PM degradation and visible light illumination treatment was determined to be 0.0206 min, with a similar constant of 0.0202 min observed for TOC degradation. Remarkably, SZHP exhibited superior PM removal rates compared with SmEuSbO, ZnBiSbO, or N-doped TiO photocatalyst, accompanied by removal rates 1.09 times, 1.20 times, or 2.38 times higher, respectively. Furthermore, the study investigated the oxidizing capability of free radicals through the use of trapping agents. The results showed that hydroxyl radicals had the strongest oxidative capability, followed by superoxide anions and holes. These findings provide a solid scientific foundation for future research and development of efficient heterojunction compound catalysts.
PubMed: 38067453
DOI: 10.3390/molecules28237722 -
Food Chemistry Jun 2024In this study, a cascade nanobioreactor was developed for the highly sensitive detection of methyl parathion (MP) in food samples. The simultaneous encapsulation of...
In this study, a cascade nanobioreactor was developed for the highly sensitive detection of methyl parathion (MP) in food samples. The simultaneous encapsulation of acetylcholinesterase (AChE) and choline oxidase (CHO) in a zeolitic imidazole ester backbone (ZIF-8) effectively improved the stability and cascade catalytic efficiency of the enzymes. In addition, glutathione-stabilized gold nanoclusters (GSH-AuNCs) were encapsulated in ZIF-8 by ligand self-assembly, conferring excellent fluorescence properties. Acetylcholine (ATCh) is catalyzed by a cascade of AChE/CHO@ZIF-8 as well as Fe(II) to generate hydroxyl radicals (·OH) with strong oxidizing properties. The ·OH radicals then oxidize Au(0) in GSH-AuNCs@ZIF-8 to Au(I), resulting in fluorescence quenching. MP, as an inhibitor of AChE, hinders the cascade reaction and thus restores the fluorescence emission, enabling its quantitative detection. The limit of detection of the constructed nanobioreactor for MP was 0.23 µg/L. This MOF-based cascade nanobioreactor has great potential for the detection of trace hazards.
Topics: Methyl Parathion; Metal-Organic Frameworks; Acetylcholinesterase; Metal Nanoparticles; Acetylcholine; Gold; Limit of Detection
PubMed: 38219569
DOI: 10.1016/j.foodchem.2024.138389 -
Small (Weinheim An Der Bergstrasse,... Dec 2023The cost of insect pests to human society exceeds USD70 billion per year worldwide in goods, livestock, and healthcare services. Therefore, pesticides are needed to...
The cost of insect pests to human society exceeds USD70 billion per year worldwide in goods, livestock, and healthcare services. Therefore, pesticides are needed to prevent insect damage despite the secondary effects of these chemical agents on non-target organisms. Chemicals encapsulation into carriers is a promising strategy to improve their specificity. Hydrogel-based microrobots show enormous potential as chemical carriers. Herein, hydrogel chitosan magnetic microrobots encapsulating ethyl parathion (EP)-CHI@Fe O are used to efficiently kill mealworm larvae (Tenebrio molitor). The mechanism takes advantage of pH-responsive chitosan degradation at Tenebrio molitor midgut pH to efficiently deliver pesticide into the mealworm intestinal tract in just 2 h. It is observed that under a transversal rotating magnetic field, mealworm populations show higher mortality after 30 min compared to free pesticide. This example of active pesticide carriers based on soft microrobots opens new avenues for microrobots applications in the agrochemical field as active chemical carriers.
Topics: Animals; Humans; Insecticides; Chitosan; Hydrogels; Insecta; Tenebrio; Pesticides; Pest Control; Magnetic Phenomena
PubMed: 36585370
DOI: 10.1002/smll.202204887 -
Food Chemistry May 2024Advances in flexible SERS substrates has made it possible to approach the ultimate goal of rapid in-situ monitoring of fruit and vegetable safety, but its vulnerability...
Advances in flexible SERS substrates has made it possible to approach the ultimate goal of rapid in-situ monitoring of fruit and vegetable safety, but its vulnerability under laser ablation results in low utilization. In order to solve this problem, a 3D framework of TiO-doped PVDF\PVP polymer was utilized to self-assemble gold-silver core-shell nanorods (Au@Ag NRs) to prepare a flexible SERS substrate with good physical stability and self-cleaning properties. This substrate showed excellent detection limit and recyclability after the detection of three pesticide residues in apple peel. The LOD of methyl-parathion (MP) was as low as 0.037 ng/cm, with an RSD of 5.61 % for 5 cycle-detection. The recoveries of two additional pesticides thiram (TMTD) and chlorpyrifos (CPF) were 86.32 %-112.47 %. We hoped that this research will contribute to providing a recyclable and facile method for in-situ analysis of fruit and vegetable surface residues and functional manufacture of flexible SERS substrates.
Topics: Malus; Spectrum Analysis, Raman; Metal Nanoparticles; Pesticides; Pesticide Residues; Thiram; Vegetables; Gold
PubMed: 38185049
DOI: 10.1016/j.foodchem.2023.138345 -
Analytical Biochemistry Mar 2024Core-shell ZIF-8@ZIF-67 was synthesized by growing a cobalt-based ZIF-67 on a ZIF-8 seed particle. Herein, through selective etching of the ZIF-8@ZIF-67 core and...
Core-shell ZIF-8@ZIF-67 was synthesized by growing a cobalt-based ZIF-67 on a ZIF-8 seed particle. Herein, through selective etching of the ZIF-8@ZIF-67 core and subsequent direct carbonization, core-shell hollow ZnO@CoO nitrogen-doped nanoporous carbon (HZnO@CoO-NPC) nanocomposites were prepared. HZnO@CoO-NPCs possessed a high nitrogen content, large surface area, high degree of graphitization and excellent electrical conductivity, all of which were attributed to successfully integrating the unique advantages of ZIF-8 and ZIF-67. HZnO@CoO-NPCs were used to assemble acetylcholinesterase (AChE) biosensors for organophosphorus pesticides (OPs) detection. The low detection limit of 2.74 × 10 M for chlorpyrifos and 7.6 × 10 M for parathion-methyl demonstrated the superior sensing performance. The results showed that the electrochemical biosensor constructed by HZnO@CoO-NPC provided a sensitive and efficient electrochemical strategy for OPs detection.
Topics: Organophosphorus Compounds; Pesticides; Zinc Oxide; Nitrogen; Acetylcholinesterase; Insecticides; Methyl Parathion; Biosensing Techniques; Nanocomposites
PubMed: 38070664
DOI: 10.1016/j.ab.2023.115422 -
Analytical Chemistry Oct 2023An acetylcholinesterase (AChE) binding-based biosensor was developed for the ultrasensitive detection of organophosphate (OP) pesticides. The biosensor integrates the...
Competitive Assay for the Ultrasensitive Detection of Organophosphate Pesticides Based on a Fiber-Optic Particle Plasmon Resonance Biosensor and an Acetylcholinesterase Binding Peptide.
An acetylcholinesterase (AChE) binding-based biosensor was developed for the ultrasensitive detection of organophosphate (OP) pesticides. The biosensor integrates the technique based on fiber-optic particle plasmon resonance detection and a synthetic AChE binding peptide conjugated with gold nanoparticles on the optical fiber surface via an AChE competitive binding assay. The OP pesticides present in the solution hinder the binding of AChE to the peptide on the biosensor by competing for the binding sites present in AChE. The limit of detection obtained for parathion using this method was observed to be 0.66 ppt (2.3 pM). This method shows a wide linear dynamic range of 6 orders. Furthermore, the use of the AChE binding peptide in the biosensor can better discriminate OPs against carbamates by using only a single biosensor. The practical application of this method was tested using spiked samples, which yielded good recovery and reproducibility. The spiked sample required minimal pretreatment before analysis; hence, this biosensor may also be used in the field.
Topics: Acetylcholinesterase; Pesticides; Gold; Reproducibility of Results; Metal Nanoparticles; Organophosphorus Compounds; Insecticides; Organophosphates; Biosensing Techniques
PubMed: 37726976
DOI: 10.1021/acs.analchem.3c01960 -
Water Research Feb 2024Rapid and precise quantification of organophosphorus pesticides (OPPs) in environmental water bodies is crucial for evaluating ecological risks and safeguarding human...
Rapid and precise quantification of organophosphorus pesticides (OPPs) in environmental water bodies is crucial for evaluating ecological risks and safeguarding human health. Traditional instrumental methods are complex, time-consuming, and expensive, while enzyme-based biosensors suffer from instability and require a constant supply of substrates. Hence, there is an urgent need for a fast, simple, and sensitive biosensor for OPPs. In this study, we developed a novel non-enzymatic biosensor for the detection of methyl parathion (MP) by employing the bioluminescence resonance energy transfer (BRET) Q-body strategy. Optimizing the spacer arm and screening fluorescent dyes identified the R6G BRET MP Q-body sensor with the best performance. Key parameters affecting the sensor's detection performance were optimized by using single-factor experiments. Under optimal conditions, the detection exhibited a detection limit of 5.09 ng·mL and a linear range of 16.21-848.81 ng·mL. The sensor's accuracy was validated using standard recovery experiments, yielding a recovery rate of 84.47 %-102.08 % with a standard deviation of 1.93 %-9.25 %. The detection results of actual water samples demonstrate that this fast, simple, and highly sensitive BRET Q-body sensor holds great promise for practical water quality monitoring.
Topics: Humans; Pesticides; Organophosphorus Compounds; Methyl Parathion; Energy Transfer; Biosensing Techniques
PubMed: 38157605
DOI: 10.1016/j.watres.2023.121051