Blood Acetylcholinesterase Activity Research Articles

Near-Infrared Light Driven Reversible Photoelectrochemical Bioassay by S-Scheme All-Polymer Blends for Acetylcholinesterase Activity Monitoring.

Photoelectrochemical (PEC) biosensing, recognized for its heightened sensitivity, faces limitations in its application for in vivo diagnosis due to the inefficiency of UV-visible light-driven photoactive materials in nontransparent biological samples. In this study, we investigate the potential of an S-scheme all-polymer heterojunction comprising a prototype nonfullerene polymeric acceptor (PYIT) and carbon nitride to develop a near-infrared (NIR) light-driven PEC biosensor for monitoring acetylcholinesterase activity in nontransparent human whole blood. The distinct molecular structure of PYIT enables efficient light absorption in the NIR region, enhancing sensitivity in nontransparent biological samples. The biosensor functions via a proton-dependent conversion mechanism between PYIT-OH and PYIT, leveraging the selective and reversible chemical reactivity of the moieties in backbone, eliminating the need for traditional and intricate integration of a biorecognition unit. Our findings demonstrate a direct correlation between variations in photoelectric performance and acetylcholinesterase concentration, showcasing exceptional sensitivity, selectivity, and reversibility.

Sex and adrenal hormones in association with insecticide biomarkers among adolescents living in ecuadorian agricultural communities

BackgroundOrganophosphate, pyrethroid, and neonicotinoid insecticides have resulted in adrenal and gonadal hormone disruption in animal and in vitro studies; limited epidemiologic evidence exists in humans. We assessed relationships of urinary insecticide metabolite concentrations with adrenal and gonadal hormones in adolescents living in Ecuadorean agricultural communities. MethodsIn 2016, we examined 522 Ecuadorian adolescents (11-17y, 50.7% female, 22% Indigenous; ESPINA study). We measured urinary insecticide metabolites, blood acetylcholinesterase activity (AChE), and salivary testosterone, dehydroepiandrosterone (DHEA), 17β-estradiol, and cortisol. We used general linear models to assess linear (β = % hormone difference per 50% increase of metabolite concentration) and curvilinear relationships (β2 = hormone difference per unit increase in squared ln-metabolite) between ln-metabolite or AChE and ln-hormone concentrations, stratified by sex, adjusting for anthropometric, demographic, and awakening response variables. Bayesian Kernel Machine Regression was used to assess non-linear associations and interactions. ResultsThe organophosphate metabolite malathion dicarboxylic acid (MDA) had positive associations with testosterone (βboys = 5.88% [1.21%, 10.78%], βgirls = 4.10% [-0.02%, 8.39%]), and cortisol (βboys = 6.06 [-0.23%, 12.75%]. Para-nitrophenol (organophosphate) had negatively-trending curvilinear associations, with testosterone (β2boys = −0.17 (−0.33, −0.003), p = 0.04) and DHEA (β2boys = −0.49 (−0.80, −0.19), p = 0.001) in boys. The neonicotinoid summary score (βboys = 5.60% [0.14%, 11.36%]) and the neonicotinoid acetamiprid-N-desmethyl (βboys = 3.90% [1.28%, 6.58%]) were positively associated with 17β-estradiol, measured in boys only. No associations between the pyrethroid 3-phenoxybenzoic acid and hormones were observed. In girls, bivariate response associations identified interactions of MDA, Para-nitrophenol, and 3,5,6-trichloro-2-pyridinol (organophosphates) with testosterone and DHEA concentrations. In boys, we observed an interaction of MDA and Para-nitrophenol with DHEA. No associations were identified for AChE. ConclusionsWe observed evidence of endocrine disruption for specific organophosphate and neonicotinoid metabolite exposures in adolescents. Urinary organophosphate metabolites were associated with testosterone and DHEA concentrations, with stronger associations in boys than girls. Urinary neonicotinoids were positively associated with 17β-estradiol. Longitudinal repeat-measures analyses would be beneficial for causal inference.

Cholinesterase activities and sepsis-associated encephalopathy in viral versus nonviral sepsis

PurposeThere is evidence that cholinergic imbalance secondary to neuroinflammation plays a role in the pathophysiology of sepsis-associated encephalopathy (SAE). Blood acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities have been proposed as surrogate parameters for the cholinergic function of the central nervous system. Viral sepsis is associated with systemic inflammation and BChE has been reported to be of prognostic value in a small cohort of COVID-19 patients. Nevertheless, the prognostic value of AChE in patients with viral sepsis remains unclear.MethodsWe investigated the role of AChE and BChE activities as prognostic biomarkers of SAE and mortality in patients with viral vs nonviral sepsis enrolled in two prospective cohort studies. We quantified the AChE and BChE activities in whole blood of patients at two time points in the acute phase of viral sepsis (N = 108) and compared them with the activities in patients with nonviral sepsis (N = 117) and healthy volunteers (N = 81). Patients were observed until discharge from the intensive care unit (ICU).ResultsThree days after sepsis onset, the median [interquartile range] levels of AChE and BChE were reduced in both patients with viral sepsis (AChE, 5,105 [4,010–6,250] U·L−1; BChE, 1,943 [1,393–2,468] U·L−1) and nonviral sepsis (AChE, 4,424 [3,630–5,055] U·L−1; BChE, 1,095 [834–1,526] U·L−1) compared with healthy volunteers (AChE, 6,693 [5,401–8,020] U·L−1; BChE, 2,645 [2,198–3,478] U·L−1). Patients with viral sepsis with SAE during their ICU stay had lower AChE activity three days after sepsis onset than patients without SAE (4,249 [3,798–5,351] U·L−1vs 5,544 [4,124–6,461] U·L−1). Butyrylcholinesterase activity seven days after sepsis onset was lower in patients with viral sepsis who died in the ICU than in surviving patients (1,427 [865–2,181] U·L−1vs 2,122 [1,571–2,787] U·L−1).ConclusionCholinesterase activities may be relevant prognostic markers for the occurrence of SAE and mortality in the ICU in patients with viral sepsis.Study registrationThis study constitutes an analysis of data from the ongoing studies ICROS (NCT03620409, first submitted 15 May 2018) and ICROVID (DRKS00024162, first submitted 9 February 2021).

Potentials of Acetylcholinesterase and Butyrylcholinesterase Alterations in On-Pump Coronary Artery Bypass Surgery in Postoperative Delirium: An Observational Trial.

Cardiac surgery is regularly associated with postoperative delirium (POD), affected by neuro-inflammation and changes in cholinergic activity. Therefore, this prospective observational study aimed to evaluate whether pre- and perioperative changes in blood acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity were associated with POD development in patients undergoing isolated elective coronary artery bypass graft (CABG) surgery. It included 93 patients. Pre- and postoperative blood AChE and BChE activities were measured with photometric rapid-point-of-care-testing. The Intensive Care Delirium Screening Checklist and the Confusion Assessment Method for the Intensive Care Unit were used to screen patients for POD. POD developed in 20 patients (21.5%), who were older (p = 0.003), had higher EuroSCOREs (p ≤ 0.001), and had longer intensive care unit stays (p < 0.001). On postoperative day one, BChE activity decreased from preoperative values more in patients with (31.9%) than without (23.7%) POD (group difference p = 0.002). Applying a cutoff of ≥32.0% for BChE activity changes, receiver operating characteristic analysis demonstrated a moderate prediction capability for POD (area under the curve = 0.72, p = 0.002). The risk of developing POD was 4.31 times higher with a BChE activity change of ≥32.0% (p = 0.010). Monitoring the pre- to postoperative reduction in BChE activity might be a clinically practicable biomarker for detecting patients at risk of developing POD after CABG surgery.

Biomarkers profile and neurobehavioral functioning in pesticide exposed populations in northern Chile.

Background. In Chile, several organophosphates (OP) pesticides banned in other countries are still used for insect control in agriculture. Acute intoxications of agricultural workers frequently occur and they must be notified to the surveillance system of the Ministry of Health. However the impact of chronic and environmental pesticide exposure in the general population has been less studied. Long-term exposure to OP is associated to neurobehavioral impairment and is also considered a risk factor for neurodegenerative pathologies.Methods: We recruited volunteers from rural towns located in northern Chile were agricultural activities are carried on. Volunteers (men and women among 18 and 50 years old, with at least 5 years living in the area or working in agriculture) were classified as environmentally (EE) or occupationally exposed (OE) according to a survey that asked sociodemographic, morbidity and exposure antecedents. Each participant underwent a neuropsychological evaluation using a battery of 21 test that covered areas of memory, attention, executive functions, praxis, psychomotricity and emotion. Inhibition values of blood acetylcholinesterase (AChE) and butyrilcholinesterase (BChE) activities during the spray season were obtained in both exposure groups.Results and Discussion: BChE activity was significantly inhibited in EE and OE, showing the EE group the highest magnitude of inhibition. Frequencies of inhibition above 30% (biological tolerance limit declared by Chilean legislation) indicated that AChE is the most frequently inhibited enzyme in the OE whereas BChE is for EE. In pre-spray neurobehavioral evaluations, the OE group showed the highest frequency of low-performance individuals, followed by the EE group. For the majority of tests, the performance worsened during the spraying season. The most affected domains were memory, executive function, and psychomotricity. Poor associations were found between enzyme activities and neurobehavioral outcomes. Systematic biomonitoring and health outcomes studies are necessary to improve environmental and occupational health policies in Chile.

Blood acetylcholinesterase activity is associated with increased 10 year all-cause mortality following coronary angiography

Background and aimsParasympathetic dysfunction is associated with increased risk for major adverse cardiovascular events (MACE). However, clinically validated biomarkers that reflect parasympathetic activity are not yet available. We sought to assess the ability of serum cholinesterase activity to predict long term survival in patients undergoing coronary angiography. MethodsWe prospectively followed 1002 consecutive patients undergoing clinically indicated coronary angiography (acute coronary syndrome or stable angina). We measured blood acetylcholinesterase (AChE) activity using the acetylcholine analog acetylthiocholine. Mortality rates were determined up to 10 years of follow-up. We divided our cohort into 3 groups with low, intermediate and high AChE activity by a Chi-square automatic interaction detection method (CHAID). ResultsPatients with lower than cutoff levels of AChE (<300 nmol/min/ml) had higher mortality rates over 10 years of follow-up, after adjusting for conventional risk factors, biomarkers, clinical indication, and use of medications (HR = 1.6, 95% CI 1.1–2.5, p = 0.02). Patients with intermediate levels of AChE (300–582 nmol/min/ml) were also at increased risk for death (HR = 1.4, 95% CI 1.1–1.9, p = 0.02). AChE was inversely correlated with C-reactive protein, troponin I, fibrinogen and neutrophil/lymphocyte ratio levels. ConclusionsPatients presenting for coronary angiography with low levels of serum AChE activity are at increased risk for death during long term follow-up.

SAT-133 BLOOD ACETYLCHOLINESTERASE ACTIVITY AND COMPARATIVE eGFR IN RURAL FARMERS WITH LOW, INTERMEDIATE, AND HIGH EXPOSURE TO ORGANOPHOSPHOROUS CONTAINING AGROCHEMICALS

Organophosphorous containing agrochemicals (OCAs) are commonly used by farmers to prevent destruction of farm products by pests and weeds. Their role as risk factors of kidney disease is currently being evaluated. Blood acetylcholinesterase inhibition is a recognized marker of exposure to organophosphorous containing chemicals. We conducted a study to determine the proportion of rural farmers who use these agents, their blood acetylcholinesterase activities and comparative estimated glomerular filtration rate (eGFR) in those with low, intermediate, and high exposure. A cross-sectional study of nine rural farming communities in Southwestern Nigeria. Degree of exposure was categorized using the following criteria: (a) Years of active farming - Low (0-10 years) and High (> 10 years), (b) Use of protective garment - Low (Yes), High (No). A score of low for both parameters was categorized as low exposure, a score of low and high in both parameters was graded as intermediate exposure, while a score of high in both parameters was graded as high exposure. All participants were evaluated for kidney function using CKD-EPI equation to calculate the eGFR. Blood acetylcholinesterase activity was evaluated by the modified Ellman’s method. Five hundred and seventy two farmers participated in the study. Two hundred and twenty five (39.3%) were males while 347 (60.7%) were females. Mean age of participants was 52 ± 17.5 (range 18 – 100) years. Years of active farming ranged from 0.5 to 80 years, with a median of 25 years. Blood acetylcholinesterase activity ranged from 0 – 20.1 (mean 3.5 ± 3.5) µmol/min/mL in all participants. Four hundred participants (69.9%) stated that they used organophosphate containing agrochemicals. Exposure was low in 32 (8%), intermediate in 161 (40.6%), and high in 200 (50%) of these participants. Blood acetylcholinesterase activities / eGFR levels in low, intermediate, and high exposures are shown in the table. Statistically, blood acetylcholinesterase activities were similar in those with high compared to those with low exposure (P = 0.338). However, eGFR was significantly lower in those with high compared to those with low exposure (P = 000). Use of organophosphate containing agrochemicals was high in the rural farmers examined. There was a decline in eGFR with higher exposure. However, blood acetylcholinesterase activity levels did not appear to differ significantly among the different groups of exposure studied. There is a need for a prospective study to determine the normal range of blood acetylcholinesterase levels in unexposed individuals to define the minimum duration of exposure to organophosphate agrochemicals neccessary for significant surpression of blood of acetylcholinesterase levels in the rural farmers.

Exogenous melatonin restrains neuroinflammation in high fat diet induced diabetic rats through attenuating indoleamine 2,3-dioxygenase 1 expression

Aim of the workNeuroinflammation can arise from metabolic disturbances accompanying type 2 diabetes mellitus (T2DM) with an implication of indoleamine 2,3-dioxygenase 1 (IDO1). The antioxidant and anti-inflammatory potentials of melatonin (Mel) can amend diabetic complications. Here, we examined the effect of exogenous melatonin on neuroinflammation in high fat diet (HFD)-induced T2DM rats. Main methodsTwenty-one adult male Sprague-dawley rats were divided in to three groups: control group: fed commercial standard rat chow, T2DM group: fed with HFD for 16 weeks, and T2DM-Mel group: received HFD for 8 weeks, followed by weekly melatonin treatment (i.p injection 10 mg/kg in saline) for 8 weeks with continuous supply of HFD. After which, animals were submitted to euthanasia for brain and blood samples collection. Key findingsIn T2DM-Mel group the diabetic profile was ameliorated, and the state of low-grade systemic inflammation was alleviated through lowering serum pro-inflammatory cytokines (TNF-α and IL-6) and leptin while increasing adiponectin. Melatonin improved brain oxidative stress by increasing total antioxidant capacity and reduced glutathione (GSH), whereas malondialdehyde was declined. Melatonin reduced acetylcholinesterase (AChE) activity in blood and brain and its hippocampal expression, also hippocampal inducible nitric oxide synthase (iNOS) expression was reduced, moreover IDO1 hippocampal expression was declined, furthermore recovered neuronal morphology following melatonin treatment was also clearly viewed in the hippocampus under the light microscope in T2DM-Mel rats. SignificanceMelatonin can be considered as a promising solution in preventing neuroinflammation development in T2DM owing to its ability to render the oxidative stress and accompanied low-grade systemic inflammation.

Bovine Endometritis and the Inflammatory Peripheral Cholinergic System.

Endometritis is an inflammation of the endometrium associated with bacterial infection. The pathogenesis of endometritis in cows is still not completely understood. The combined analysis of the markers of inflammation and oxidative stress has contributed to a better understanding of disease mechanisms, but is still unexplored in uterine disorders. Moreover, research provides evidence about an important role of the vagus nerve in regulating the innate immune function through the cholinergic anti-inflammatory pathway in response to bacterial infections. This new pathway has demonstrated a critical role in controlling the inflammatory system. The aim of this study was to evaluate the activity of cholinesterase in total blood, lymphocytes, and serum of dairy cows with clinical and subclinical endometritis. Sixty-one Holstein cows, between 30 and 45 days in milk, were classified into 3 groups of animals: presenting clinical endometritis (n = 22), subclinical endometritis (n = 17), and healthy (n = 22). Mean leukocyte counts did not differ among groups, but the neutrophil number was significantly higher in cows with clinical endometritis than those in healthy animals. Also, serum concentration of interleukin-1beta (pg/mL) was significantly higher in cows with endometritis. The activity of acetylcholinesterase in blood and lymphocytes increased in both groups with endometritis. Animals with endometritis presented an increase in lipid peroxidation, but the antioxidant enzyme activity (catalase levels) was higher in endometritis groups than in normal cows. In conclusion, the inflammatory process of clinical and subclinical endometritis leads to systemic lipid peroxidation despite the compensatory increase of the antioxidant enzyme. These data also provide evidence of an important role of the cholinergic pathway in regulating dairy cows with clinical and subclinical endometritis.

Occupational pesticide exposure and symptoms of attention deficit hyperactivity disorder in adolescent pesticide applicators in Egypt

BackgroundExposure to environmental chemicals, including organophosphorus pesticides, is associated with behavioral disorders such as attention deficit hyperactivity disorder (ADHD). However, the impact of occupational pesticide exposure on ADHD development in adolescents has not been examined. ObjectiveWe examined the association between exposure to chlorpyrifos and ADHD symptoms among adolescents in Egypt. MethodsAdolescent pesticide applicators and non-applicators, 12–21 years old, participated in a 10-month longitudinal study examining health effects from pesticide exposure. Repeated urine and blood samples were collected at various time points during the 10-months to assess biomarkers of chlorpyrifos exposure (urinary trichloro-2-pyridinol or TCPy) and effect (blood acetyl cholinesterase activity and butyryl cholinesterase activity). Parents from a subset of the cohort (N = 64) completed the Short Form of Conners’ Parent Rating Scale – Revised. Poisson regressions were used to examine the associations between the number of ADHD symptoms and occupation and biomarkers. ResultsPesticide applicators had significantly more symptoms of ADHD than participants in the non-applicator group. Urinary TCPy levels were associated with increased symptoms, demonstrating a dose-response effect. Applicators with ADHD reported applying pesticides for more hours during the application season and had greater cumulative TCPy levels than participants without ADHD. One fourth of all applicators met the criteria for an ADHD diagnosis (having 6 or more reported symptoms). ConclusionsThis study provides preliminary evidence of an association between occupational exposure to chlorpyrifos and ADHD symptoms among adolescent pesticide applicators in spite of its limited small sample size. There is a critical need to investigate the susceptibility of children and adolescents to repeated occupational and environmental exposures to pesticides because the developing brain may be uniquely sensitive to the neurotoxic effects of these agents.

Oxidative stress linked to changes of cholinesterase and adenosine deaminase activities in experimentally infected chicken chicks with Eimeria spp

Both oxidative stress and alterations in adenosinergic and cholinergic systems participate in initiation and progression of parasitic infectious diseases. Nevertheless, the involvement of these pathways during eimeriosis remains poorly understood. Therefore, the aim of this study was to evaluate the involvement of adenosinergic and cholinergic systems in regulation of inflammatory response and oxidative stress in chicken chicks experimentally infected with Eimeria spp. Two groups were formed for comparison at 3 time points (days 5, 10 and 15) of infection (PI): uninfected (control) and infected. Erythrocyte counts, hematocrit and hemoglobin levels were lower in infected chicks on day 15 post-infection (PI). Total leukocytes, heterophil and lymphocyte counts were higher in infected chicks on days 5 and 10 PI, while eosinophil counts were higher only on day 10 PI. Serum levels of total protein and globulins were higher in infected chicks on days 10 and 15 PI, while triglycerides and cholesterol levels were lower on day 15 PI. Acetylcholinesterase activity in total blood and butyrylcholinesterase activity in serum were higher in infected chicks on day 15 PI, while adenosine deaminase activity was higher on day 10 PI and lower on day 15 PI compared with the respective control. Finally, serum levels of reactive oxygen species and catalase activity in total blood were higher in infected chicks on day 15 PI, while superoxide dismutase activity in total blood was lower at the same time of infection. These data suggest that cholinergic and adenosinergic systems display a pro-inflammatory profile that contributes to impairment of immune and inflammatory responses in a mixed Eimeria infection. Furthermore, oxidative stress may contribute to clinical signs of disease as well as to pathogenesis. In summary, the impairment of immune response and alterations in blood antioxidant/oxidant status contributes to disease pathophysiology.

The Rat (Rattus norvegicus) as a Model Object for Acute Organophosphate Poisoning. 1. Biochemical Aspects

The long-term effects of acute organophosphate (OP) poisoning remain poorly studied, while experimental models usually disregard species-related specificity of rodents as model objects. Here we present two toxicological models and a comparative analysis of a wide range of biochemical blood indices in their dynamics over 3 months after acute rat poisoning with paraoxon. As expected, the most sensitive biochemical index within the first hours and days after OP poisoning was whole blood acetylcholinesterase activity, which decreased by almost an order of magnitude in all experimental groups 3 h after poisoning. Changes in the parameters of carbohydrate and fat metabolism (triglyceride, free fatty acid, D-3-hydroxybutyrate, cholesterol and glycerol levels) were detected in experimental groups at different time points after poisoning. Statistically significant changes in a number of biochemical markers were found in positive control rats relative to intact rodents.

A ratiometric fluorescence probe based on carbon dots for discriminative and highly sensitive detection of acetylcholinesterase and butyrylcholinesterase in human whole blood

A ratiometric fluorescence probe based on carbon dots (CDs) was developed for discriminative and highly sensitive detection of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity in human whole blood. When o-phenylenediamine (OPD) was oxidized by Cu2+, the product 2,3-diaminophenazine (oxOPD) could effectively quench the fluorescence of CDs at 460 nm due to the inner filter effect and gave rise to a new emission peak at 570 nm. The AChE or BChE catalyzed hydrolysis reaction of acetylthiocholine or butyrylthiocholine to generate thiocholine, whose sulfhydryl group strongly captured Cu2+ to inhibit the oxidization of OPD, thus effectively preserving the natural fluorescence emission of CDs. The resulting fluorescence intensity ratio served as the signal output of the probe for cholinesterases (ChEs) activity sensing. The activities of AChE and BChE were determined to range from 0.2 to 14.0 U L−1 and from 0.1 to 5.0 U L−1, with detection limits of 0.1 U L−1 and 0.04 U L−1, respectively. Additionally, the IC50 of tacrine and ethopropazine for the inhibition of AChE and BChE were estimated to be 29.8 nM and 132.6 nM, respectively. Moreover, the probe was successfully applied to the discriminative determination of AChE and BChE in human whole blood without any pretreatment. These results suggested that the proposed strategy provided a discriminative, sensitive and robust analytical platform for ChEs clinical diagnostics and drug screening.

On-substrate Enzymatic Reaction to Determine Acetylcholinesterase Activity in Whole Blood by Paper Spray Mass Spectrometry

Currently, all assays measuring acetylcholinesterase (AChE) activity following a suspected nerve agent exposure leverage methodologies that fail to identify the agent. This limits the overall effectiveness and ability to administer proper countermeasures. As such, there is an urgent need to identify novel, rapid, and more comprehensive approaches to establish AChE activity, including identification of the toxicant. Paper spray mass spectrometry was used to monitor the activity of acetylcholinesterase, both in-solution and on modified hydrophobic paper surface. Hydrophobic paper surfaces were prepared using vaporized trichloro(3,3,3-trifluoropropyl)silane. In both approaches, mixtures of diluted human whole blood with and without VX were mixed with a non-endogenous AChE specific substrate, 1,1-dimethyl-4-acetylthiomethylpiperidinium (MATP+). Formation of the cleaved MATP+ product was monitored over time and compared to MATP+ to determine relative AChE activity. This on-substrate assay was effective at determining AChE activity and identifying the toxicant; however, determination of AChE activity in-solution proceeded at a slower rate. The on-substrate assay serves as a pioneering example of an enzymatic reaction occurring on the surface of a paper spray ionization ticket. This work broadens the range of applications relating to paper spray ionization-based clinical diagnostic assays.Graphical ᅟ

Biomarkers of exposure and effect in a working population exposed to lead, manganese and arsenic

ABSTRACT Lead (Pb), manganese (Mn) and arsenic (As) are among the major toxicants in mining environments. Miners are commonly and repeatedly exposed to this toxic mixture. Some adverse effects may appear at concentrations below environmental quality guidelines for individual mixture components. Further, Pb, Mn, and As induce common adverse outcomes, such as interferences in the cholinergic system and heme synthesis. It is thus vital to monitor miners through biomarkers (BM), such that subclinical effects may be identified at an early stage. The main objectives of this study were to evaluate the exposure of a mining population to these three metals and determine alterations in cholinergic and heme synthesis parameters. Blood and urine samples of workers (n = 60) were obtained from a Portuguese mining industry and compared with a control population (n = 80). The levels of the metals were determined in biological samples, as well as urinary heme precursor levels, delta aminolevulinic acid (ALA) and porphyrins, and blood acetylcholinesterase (AChE) activity. The miners exhibited significantly higher values of Pb and As in blood and urine compared to control. In the case of Mn near or slightly higher than limit values were found. Our data show that heme precursors may be used simultaneously with metal levels as BMs for multiple metal exposures on an individual basis, resulting in 94.3% and 95.7% accuracy, respectively, in blood and urine, for subjects correctly identified with respect to occupation. This study also revealed that biological monitoring of this working population regarding metal body burden and heme precursor accumulation is advisable.

Xuebijing injection induces anti-inflammatory-like effects and downregulates the expression of TLR4 and NF-κB in lung injury caused by dichlorvos poisoning

BackgroundThe mechanism in lung injury caused by acute organophosphate pesticide poisoning (AOPP) and an effective treatment remains unclear. We aim to clarify how the inflammatory lung injury caused by AOPP might be modulated by Xuebijing (XBJ) injection. MethodsAOPP-induced lung injury model was induced by dichlorvos (DDVP) subcutaneous administration in rats and XBJ injection was administered by intraperitoneal injection after DDVP challenge. The effects of XBJ injection were assessed by lung histopathological analysis and lung injury scores, lung wet-to-dry weight ratios (WDR) and oxygenation, differential immune cell count in bronchoalveolar lavage fluid (BALF), IL-6 and TNF-α levels in blood, the levels of TLR4 and NF-κB proteins in lung tissue and blood acetylcholinesterase (AChE) activity. ResultsDDVP administration resulted in damage of lung histopathology and lower PaO2/FiO2 ratios (P < 0.05), which were notably attenuated by XBJ injection (P < 0.05). Total cell, macrophage, and neutrophils count in BALF and TNF-α and IL-6 levels in blood were significantly increased after DDVP exposure (P < 0.05), which were notably ameliorated by XBJ injection (P < 0.05). TLR4 and NF-κB protein in lung tissue expression after DDVP challenge were markedly increased (P < 0.05), and they were substantially downregulated by XBJ injection (P < 0.05). In addition, blood AChE activity was significantly decreased by DDVP administration (P < 0.05), however, there was no significant improvement after XBJ injection. ConclusionXBJ injection prevents DDVP poisoning induced lung injury by attenuating the inflammatory response. The protective effect appears to be mediated through downregulation of the TLR4 and NF-κB expression.

Quercetin treatment regulates the Na+,K+-ATPase activity, peripheral cholinergic enzymes, and oxidative stress in a rat model of demyelination

Quercetin is reported to exert a plethora of health benefits through many different mechanisms of action. This versatility and presence in the human diet has attracted the attention of the scientific community, resulting in a huge output of in vitro and in vivo (preclinical) studies. Therefore, we hypothesized that quercetin can protect Na+,K+-ATPase activity in the central nervous system, reestablish the peripheral cholinesterases activities, and reduce oxidative stress during demyelination events in rats. In line with this expectation, our study aims to find out how quercetin acts on the Na+,K+-ATPase activity in the central nervous system, peripheral cholinesterases, and stress oxidative markers in an experimental model of demyelinating disease. Wistar rats were divided into 4 groups: vehicle, quercetin, ethidium bromide (EB), and EB plus quercetin groups. The animals were treated once a day with vehicle (ethanol 20%) or quercetin 50 mg/kg for 7 (demyelination phase, by gavage) or 21 days (remyelination phase) after EB (0.1%, 10 μL) injection (intrapontine).The encephalon was removed, and the pons, hypothalamus, cerebral cortex, hippocampus, striatum, and cerebellum were dissected to verify the Na+,K+-ATPase activity. Our results showed that quercetin protected against reduction in Na+,K+-ATPase in the pons and cerebellum in the demyelination phase, and it increased the activity of this enzyme in the remyelination phase. During the demyelination, quercetin promoted the increase in acetylcholinesterase activity in whole blood and lymphocytes induced by EB, and it reduced the increase in acetylcholinesterase activity in lymphocytes in the remyelination phase. On day 7, EB increased the superoxide dismutase and decreased catalase activities, as well as increased the thiobarbituric acid–reactive substance levels. Taken together, these results indicated that quercetin regulates the Na+,K+-ATPase activity, affects the alterations of redox state, and participates in the reestablishment of peripheral cholinergic activity during demyelinating and remyelination events.

Hybridization chain reaction and DNAzyme-based dual signal amplification strategy for sensitive colorimetric sensing of acetylcholinesterase activity and inhibitor screening in rat blood

We have constructed a novel colorimetric sensing platform for quantitative detection of acetylcholinesterase (AChE) activity and its inhibitor (donepezil) in rat blood, which integrates the signal amplification of DNAzyme and hybridization chain reaction (HCR) with the assembly of gold nanoparticles (AuNPs). Herein, in the presence of AChE and its substrate acetylthiocholine (ATCh), the sensing system exhibits a dramatic decrease in absorbance at 522 nm, where AChE hydrolyzes ATCh into thiocholine, the resulting thiols capture Cu2+ from DNAzyme, and then the substrate strand of DNAzyme acts as an initiator to trigger HCR process. The HCR products can induce the assembly of AuNPs via DNA hybridization, accompanying by a sharp color-change from red to blue. When donepezil is added, the enzymatic activity of AChE is suppressed, resulting in an increase in the absorbance at 522 nm. Under optimal conditions, the colorimetric sensing platform shows sensitive responses to AChE and donepezil in the range of 0.02–1.5 mU mL−1 and 0.5–100 nM, respectively. The detection limits of AChE and donepezil are as low as 5 μU mL−1 and 0.5 nM, respectively. Owing to high sensitivity of the proposed method, various nonspecific interactions can be eliminated with a sufficient dilution, indicating that our strategy has great potential for practical application in neurobiology and pharmacology fields.

Potential short-term neurobehavioral alterations in children associated with a peak pesticide spray season: The Mother’s Day flower harvest in Ecuador

BackgroundExposures to cholinesterase inhibitor pesticides (e.g. organophosphates) have been associated with children’s neurobehavioral alterations, including attention deficit and impulsivity. Animal studies have observed transient alterations in neurobehavioral performance in relation to cholinesterase inhibitor pesticide exposures; however, limited evidence exists regarding transient effects in humans. MethodsWe estimated the associations between neurobehavioral performance and time after Mother’s Day flower harvest (the end of a heightened pesticide usage period) among 308 4-to 9-year-old children living in floricultural communities in Ecuador in 2008 who participated in the ESPINA study. Children’s neurobehavior was examined once (NEPSY-II: 11 subtests covering 5 domains), between 63 and 100days (SD: 10.8days) after Mother’s Day harvest (blood acetylcholinesterase activity levels can take 82days to normalize after irreversible inhibition with organophosphates). ResultsThe mean (SD) neurobehavioral scaled scores across domains ranged from 6.6 (2.4) to 9.9 (3.3); higher values reflect greater performance. Children examined sooner after Mother’s Day had lower neurobehavioral scores than children examined later, in the domains of (score difference per 10.8days, 95%CI): Attention/Inhibitory Control (0.38, 0.10–0.65), Visuospatial Processing (0.60, 0.25–0.95) and Sensorimotor (0.43, 0.10–0.77). Scores were higher with longer time post-harvest among girls (vs. boys) in Attention/Inhibitory Control. ConclusionsOur findings, although cross-sectional, are among the first in non-worker children to suggest that a peak pesticide use period may transiently affect neurobehavioral performance, as children examined sooner after the flower harvest had lower neurobehavioral performance than children examined later. Studies assessing pre- and post-exposure measures are needed.

The influence of enzymatic removal of chlorpyrifos from feed grain-mixture on the biochemical parameters of rat blood

Organophosphorus pesticides (OP) are used to protect crops from pests. Treatment of plants and animals with pesticides can be done during their growth or creation of conditions necessary for the long-shelf life of the agricultural products. Currently, there are many remedies for prevention and removal of intoxication consequences developed under the action of OP in living organisms. The development of biologics for the degradation of OP and biotechnologies for their application in agriculture is relevant. New biologics based on the stabilized forms of such enzyme as hexahistidine-tagged organophosphorus hydrolase (His6-OPH) in the form of nano-sized particles were tried for OP detoxification. These biologics (enzyme-polyelectrolyte complexes, EPC) were obtained in accordance to previously developed procedure by mixing solutions of His6-OPH and polyanion under certain conditions. The main purpose of this work was to evaluate the usage efficiency of EPC based on His6-OPH and polyglutamic acid for OP detoxification by analyzing biochemical blood parameters of rats consumed the grain-mixture containing chlorpyrifos. The experiment was conducted using female Sprague Dawley albino rats. Treatment of feeding grain-mixture initially containing chlopyrifos (48 mg/kg of the mixture) with EPC based on His6-OPH (1000 U/kg of the mixture) for 24 h was the most effective. The results showed that rats from the group consuming food after enzymatic removal of chlorpyrifos, had comparable acetyl cholinesterase activity in blood of rats consuming pure food (without any OP intoxication).