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Sample records for acetylcholinesterase

  1. Acetylcholinesterase Inhibitors: Pharmacology and Toxicology

    Čolović, Mirjana B.; Krstić, Danijela Z; Lazarević-Pašti, Tamara D; Bondžić, Aleksandra M; Vasić, Vesna M

    2013-01-01

    Acetylcholinesterase is involved in the termination of impulse transmission by rapid hydrolysis of the neurotransmitter acetylcholine in numerous cholinergic pathways in the central and peripheral nervous systems. The enzyme inactivation, induced by various inhibitors, leads to acetylcholine accumulation, hyperstimulation of nicotinic and muscarinic receptors, and disrupted neurotransmission. Hence, acetylcholinesterase inhibitors, interacting with the enzyme as their primary target, are appl...

  2. Possibility of Acetylcholinesterase Overexpression in Alzheimer Disease Patients after Therapy with Acetylcholinesterase Inhibitors

    Alžběta Kračmarová

    2015-08-01

    Full Text Available Acetylcholinesterase is an enzyme responsible for termination of excitatory transmission at cholinergic synapses by the hydrolyzing of a neurotransmitter acetylcholine. Nowadays, other functions of acetylcholinesterase in the organism are considered, for example its role in regulation of apoptosis. Cholinergic nervous system as well as acetylcholinesterase activity is closely related to pathogenesis of Alzheimer disease. The mostly used therapy of Alzheimer disease is based on enhancing cholinergic function using inhibitors of acetylcholinesterase like rivastigmine, donepezil or galantamine. These drugs can influence not only the acetylcholinesterase activity but also other processes in treated organism. The paper is aimed mainly on possibility of increased expression and protein level of acetylcholinesterase caused by the therapy with acetylcholinesterase inhibitors.

  3. Possibility of Acetylcholinesterase Overexpression in Alzheimer Disease Patients after Therapy with Acetylcholinesterase Inhibitors.

    Kračmarová, Alžběta; Drtinová, Lucie; Pohanka, Miroslav

    2015-01-01

    Acetylcholinesterase is an enzyme responsible for termination of excitatory transmission at cholinergic synapses by the hydrolyzing of a neurotransmitter acetylcholine. Nowadays, other functions of acetylcholinesterase in the organism are considered, for example its role in regulation of apoptosis. Cholinergic nervous system as well as acetylcholinesterase activity is closely related to pathogenesis of Alzheimer disease. The mostly used therapy of Alzheimer disease is based on enhancing cholinergic function using inhibitors of acetylcholinesterase like rivastigmine, donepezil or galantamine. These drugs can influence not only the acetylcholinesterase activity but also other processes in treated organism. The paper is aimed mainly on possibility of increased expression and protein level of acetylcholinesterase caused by the therapy with acetylcholinesterase inhibitors.

  4. Musical hallucinations treated with acetylcholinesterase inhibitors

    Jan Dirk eBlom

    2015-04-01

    Full Text Available Musical hallucinations are relatively rare auditory percepts which, due to their intrusive nature and the accompanying fear of impending mental decline, tend to cause significant distress and impairment. Although their etiology and pathophysiology appear to be heterogeneous and no evidence-based treatment methods are available, case reports indicate that acetylcholinesterase inhibitors may yield positive results in patients with comorbid hearing loss. We present two female patients (aged 76 and 78 years both of whom suffered from hearing impairment and practically incessant musical hallucinations. Both patients were successfully treated with the acetylcholinesterase inhibitor rivastigmine. Based on these two case descriptions and an overview of studies describing the use of acetylcholinesterase inhibitors in similar patients, we discuss possible mechanisms and propose further research on the use of acetylcholinesterase inhibitors for musical hallucinations experienced in concordance with hearing loss.

  5. Musical hallucinations treated with acetylcholinesterase inhibitors.

    Blom, Jan Dirk; Coebergh, Jan Adriaan F; Lauw, René; Sommer, Iris E C

    2015-01-01

    Musical hallucinations are relatively rare auditory percepts which, due to their intrusive nature and the accompanying fear of impending mental decline, tend to cause significant distress and impairment. Although their etiology and pathophysiology appear to be heterogeneous and no evidence-based treatment methods are available, case reports indicate that acetylcholinesterase inhibitors may yield positive results in patients with comorbid hearing loss. We present two female patients (aged 76 and 78 years) both of whom suffered from hearing impairment and practically incessant musical hallucinations. Both patients were successfully treated with the acetylcholinesterase inhibitor rivastigmine. Based on these two case descriptions and an overview of studies describing the use of acetylcholinesterase inhibitors in similar patients, we discuss possible mechanisms and propose further research on the use of acetylcholinesterase inhibitors for musical hallucinations experienced in concordance with hearing loss.

  6. Synthesis of Novel Chalcones as Acetylcholinesterase Inhibitors

    Thanh-Dao Tran

    2016-07-01

    Full Text Available A new series of benzylaminochalcone derivatives with different substituents on ring B were synthesized and evaluated as inhibitors of acetylcholinesterase. The study is aimed at identification of novel benzylaminochalcones capable of blocking acetylcholinesterase activity for further development of an approach to Alzheimer’s disease treatment. These compounds were produced in moderate to good yields via Claisen-Schmidt condensation and subjected to an in vitro acetylcholinesterase inhibition assay, using Ellman’s method. The in silico docking procedure was also employed to identify molecular interactions between the chalcone compounds and the enzyme. Compounds with ring B bearing pyridin-4-yl, 4-nitrophenyl, 4-chlorophenyl and 3,4-dimethoxyphenyl moieties were discovered to exhibit significant inhibitory activities against acetylcholinesterase, with IC50 values ranging from 23 to 39 µM. The molecular modeling studies are consistent with the hypothesis that benzylaminochalcones could exert their effects as dual-binding-site acetylcholinesterase inhibitors, which might simultaneously enhance cholinergic neurotransmission and inhibit β-amyloid aggregation through binding to both catalytic and peripheral sites of the enzyme. These derivatives could be further developed to provide novel leads for the discovery of new anti-Alzheimer drugs in the future.

  7. Flavanone glycosides as acetylcholinesterase inhibitors: Computational and experimental evidence

    C Remya

    2014-01-01

    Full Text Available Acetylcholinesterase hydrolyzes the neurotransmitter called acetylcholine and is crucially involved in the regulation of neurotransmission. One of the observable facts in the neurodegenerative disorders like Alzheimer′s disease is the decrease in the level of acetylcholine. Available drugs that are used for the treatment of Alzheimer′s disease are primarily acetylcholinesterase inhibitors with multiple activities. They maintain the level of acetylcholine in the brain by inhibiting the acetylcholinesterase function. Hence acetylcholinesterase inhibitors can be used as lead compounds for the development of drugs against AD. In the present study, the binding potential of four flavanone glycosides such as naringin, hesperidin, poncirin and sakuranin against acetylcholinesterase was analysed by using the method of molecular modeling and docking. The activity of the top scored compound, naringin was further investigated by enzyme inhibition studies and its inhibitory concentration (IC 50 towards acetylcholinesterase was also determined.

  8. Acetylcholinesterase inhibition by flavonoids from Agrimonia pilosa.

    Jung, Mankil; Park, Moonso

    2007-09-03

    In a bioassay-guided search for acetylcholinesterase (AChE) inhibitors from 180 medicinal plants, an ethyl acetate extract of whole plants of Agrimonia pilosa ledeb yielded tiliroside (1), 3-methoxy quercetin (2), quercitrin (3) and quercetin (4). We report herein for the first time that all four flavonol compounds showed significant inhibitory effects on AChE, particularly quercetin (4), which showed twice the activity of dehydroevodiamine (DHED).

  9. Acetylcholinesterase Inhibition by Flavonoids from Agrimonia pilosa

    Moonso Park

    2007-09-01

    Full Text Available In a bioassay-guided search for acetylcholinesterase (AChE inhibitors from 180 medicinal plants, an ethyl acetate extract of whole plants of Agrimonia pilosa ledeb yielded tiliroside (1, 3-methoxy quercetin (2, quercitrin (3 and quercetin (4. We report herein for the first time that all four flavonol compounds showed significant inhibitory effects on AChE, particularly quercetin (4, which showed twice the activity of dehydroevodiamine (DHED.

  10. Molecular Probe Analysis of Mammalian Brain Acetylcholinesterase

    1988-09-27

    Project and Degrees Awarded During this Reporting Period: Judith K. Marquis, Principal Investigator Thomas Biagioni , Senior Research Technician Robert...binding sites in nerve membrane vesicles. Comp. Biochem. Physiol. 80C: 203-205 (1985). 5. Volpe, L.S., T.M. Biagioni & J.K. Marquis: In vitro modulation of...Saxena, Vol. 6(1988Y.8 11. Marquis, J.K. & T.M. Biagioni : Selective inhibition of acetylcholinesterase and butyrylcholinesterase in human plasma

  11. Acetylcholinesterase Inhibitory and Antioxidant Properties of Euphorbiacharacias Latex

    Francesca Pintus

    2013-03-01

    Full Text Available The aim of the present study was to evaluate the acetylcholinesterase inhibitory capacity and the antioxidant properties of extracts of Euphorbia characias latex, a Mediterranean shrub. We performed a new extraction method involving the use of the trichloroacetic acid. The extract showed high antioxidant activity, was rich in total polyphenolic and flavonoid content and exhibited substantial inhibition of acetylcholinesterase activity.

  12. Inhibition of acetylcholinesterase by Tea Tree oil.

    Mills, Clive; Cleary, Brian J; Gilmer, John F; Walsh, John J

    2004-03-01

    Pediculosis is a widespread condition reported in schoolchildren. Treatment most commonly involves the physical removal of nits using fine-toothcombs and the chemical treatment of adult lice and eggs with topical preparations. The active constituents of these preparations frequently exert their effects through inhibition of acetylcholinesterase (AChE, EC 3.1.1.7). Increasing resistance to many preparations has led to the search for more effective treatments. Tea Tree oil, otherwise known as Melaleuca oil, has been added to several preparations as an alternative treatment of head lice infestations. In this study two major constituents of Tea Tree oil, 1,8-cineole and terpinen-4-ol, were shown to inhibit acetylcholinesterase at IC50 values (inhibitor concentrations required to give 50% inhibition) of 0.04 and 10.30 mM, respectively. Four samples of Tea Tree oil tested (Tisserand, Body Treats, Main Camp and Irish Health Culture Association Pure Undiluted) showed anticholinesterase activity at IC50 values of 0.05, 0.10, 0.08 and 0.11 microL mL(-1), respectively. The results supported the hypothesis that the insecticidal activity of Tea Tree oil was attributable, in part, to the anticholinesterase activity of Tea Tree oil.

  13. New Acetylcholinesterase Inhibitors for Alzheimer's Disease

    Mona Mehta

    2012-01-01

    Full Text Available Acetylcholinesterase (AChE remains a highly viable target for the symptomatic improvement in Alzheimer's disease (AD because cholinergic deficit is a consistent and early finding in AD. The treatment approach of inhibiting peripheral AchE for myasthenia gravis had effectively proven that AchE inhibition was a reachable therapeutic target. Subsequently tacrine, donepezil, rivastigmine, and galantamine were developed and approved for the symptomatic treatment of AD. Since then, multiple cholinesterase inhibitors (ChEI continue to be developed. These include newer ChEIs, naturally derived ChEIs, hybrids, and synthetic analogues. In this paper, we summarize the different types of ChEIs in development and their respective mechanisms of actions. This pharmacological approach continues to be active with many promising compounds.

  14. Two Step Synthesis of a Non-symmetric Acetylcholinesterase Reactivator

    Vit Koleckar

    2007-08-01

    Full Text Available The newly developed and very promising acetylcholinesterase reactivator (E-1- (2-hydroxyiminomethylpyridinium-4-(4-hydroxyiminomethylpyridinium-but-2-ene dibromide was prepared using two different pathways via a two-step synthesis involving the appropriate (E-1-(4-bromobut-2-enyl-2- or 4-hydroxyiminomethyl-pyridinium bromides. Afterwards, purities and yields of the desired product prepared by both routes were compared. Finally, its potency to reactivate several nerve agent-inhibited acetylcholinesterases was tested.

  15. Chlorpyrifos Detection by Piezoelectric Biosensor Based on Acetylcholinesterase Immobilization

    2010-01-01

    Acetylcholinesterase (AChE) was immobilized on multilayer films assembled by poly diallyldimethylammonium chloride (PDDA) and ι-carrageenan (IC) on silver-coated crystal electrode surfaces to detect the chlorpyrifos belonging to the organophosphates pesticide.Mass sensitive quartz crystal microbalance (QCM) was used to study the effect of AChE concentration and pH of phosphate buffer solution on immobilized acetylcholinesterase.The optimized conditions were as follows: pH was 6.0 which was near isoelectric ...

  16. Acetylcholinesterase modulates neurite outgrowth on fibronectin.

    Giordano, C; Poiana, G; Augusti-Tocco, G; Biagioni, S

    2007-05-04

    Acetylcholinesterase (AChE) has been reported to be involved in the modulation of neurite outgrowth. To understand the role played by different domains, we transfected neuroblastoma cells with three constructs containing the invariant region of AChE, differing in the exon encoding the C-terminus and therefore in AChE cellular fate and localization. All isoforms increased neurite extension, suggesting the involvement of the invariant domain [A. De Jaco, G. Augusti-Tocco, S. Biagioni, Alternative AChE molecular forms exhibit similar ability to induce neurite outgrowth, J. Neurosci. Res. 70 (2002) 756-765]. The peripheral anionic site (PAS) is encoded by invariant exons and represents the domain involved in non-cholinergic functions of AChE. Masking of PAS with fasciculin results in a significant decrease of neurite outgrowth in all clones overexpressing AChE. A strong reduction was also observed when clones were cultured on fibronectin. Treatment of clones with fasciculin, therefore masking PAS, abolished the fibronectin-induced reduction. The inhibition of the catalytic site cannot revert the fibronectin effect. Finally, when clones were cultured on fibronectin in the presence of heparin, a ligand of fibronectin, the inhibitory effect was completely reversed. Our results indicate that PAS could directly or indirectly mediate AChE/fibronectin interactions.

  17. Inhibitory effect of some natural and semisynthetic phenolic lipids upon acetylcholinesterase activity.

    Stasiuk, Maria; Bartosiewicz, Dominika; Kozubek, Arkadiusz

    2008-06-01

    The effect of phenolic lipids isolated from rye grains and cashew nut shell liquid (CNSL) from Anacardium occidentale and their semisynthetic derivatives on erythrocyte ghost's acetylcholinesterase activity was studied. It has been shown that all tested compounds decreased the enzymatic activity of acetylcholinesterase. This effect depends on the type of studied compounds. Three of them completely inhibit acetylcholinesterase activity at the micromolar concentration.

  18. Caffeine Inhibits Acetylcholinesterase, But Not Butyrylcholinesterase

    Petr Dobes

    2013-05-01

    Full Text Available Caffeine is an alkaloid with a stimulant effect in the body. It can interfere in transmissions based on acetylcholine, epinephrine, norepinephrine, serotonin, dopamine and glutamate. Clinical studies indicate that it can be involved in the slowing of Alzheimer disease pathology and some other effects. The effects are not well understood. In the present work, we focused on the question whether caffeine can inhibit acetylcholinesterase (AChE and/or, butyrylcholinesterase (BChE, the two enzymes participating in cholinergic neurotransmission. A standard Ellman test with human AChE and BChE was done for altering concentrations of caffeine. The test was supported by an in silico examination as well. Donepezil and tacrine were used as standards. In compliance with Dixon’s plot, caffeine was proved to be a non-competitive inhibitor of AChE and BChE. However, inhibition of BChE was quite weak, as the inhibition constant, Ki, was 13.9 ± 7.4 mol/L. Inhibition of AChE was more relevant, as Ki was found to be 175 ± 9 µmol/L. The predicted free energy of binding was −6.7 kcal/mol. The proposed binding orientation of caffeine can interact with Trp86, and it can be stabilize by Tyr337 in comparison to the smaller Ala328 in the case of human BChE; thus, it can explain the lower binding affinity of caffeine for BChE with reference to AChE. The biological relevance of the findings is discussed.

  19. Immunocytochemical demonstration of axonal and perikaryal acetylcholinesterase in human cerebral cortex.

    Mesulam, M M; Geula, C; Cosgrove, R; Mash, D; Brimijoin, S

    1991-01-25

    The adult human neocortex contains a dense net of axons and perikarya which yield an acetylcholinesterase-rich enzymatic reaction pattern in histochemical experiments. We employed a monoclonal antibody to human acetylcholinesterase and a method for the concurrent visualization of histochemical and immunohistochemical reaction-products to explore the relationship between immunological and enzymatic markers of acetylcholinesterase. We observed that the cortical axons and perikarya with a histochemically determined acetylcholinesterase-rich enzymatic activity also contain acetylcholinesterase-like immunoreactivity. This was especially informative for the intracortical acetylcholinesterase-rich perikarya of layers III and V since these neurons require prolonged incubations for histochemical detection and since they are not conspicuous in other animal species. The availability of a reliable immunohistochemical method makes it possible to investigate the distribution of the acetylcholinesterase enzyme molecule independent of its enzymatic activity.

  20. L-tyrosine administration increases acetylcholinesterase activity in rats.

    Ferreira, Gabriela K; Carvalho-Silva, Milena; Gonçalves, Cinara L; Vieira, Júlia S; Scaini, Giselli; Ghedim, Fernando V; Deroza, Pedro F; Zugno, Alexandra I; Pereira, Talita C B; Oliveira, Giovanna M T; Kist, Luiza W; Bogo, Maurício R; Schuck, Patrícia F; Ferreira, Gustavo C; Streck, Emilio L

    2012-12-01

    Tyrosinemia is a rare genetic disease caused by mutations on genes that codify enzymes responsible for tyrosine metabolism. Considering that tyrosinemics patients usually present symptoms associated with central nervous system alterations that ranges from slight decreases in intelligence to severe mental retardation, we decided to investigate whether acute and chronic administration of L-tyrosine in rats would affect acetylcholinesterase mRNA expression and enzymatic activity during their development. In our acute protocol, Wistar rats (10 and 30 days old) were killed one hour after a single intraperitoneal L-tyrosine injection (500 mg/kg) or saline. Chronic administration consisted of L-tyrosine (500 mg/kg) or saline injections 12 h apart for 24 days in Wistar rats (7 days old) and rats were killed 12 h after last injection. Acetylcholinesterase activity was measured by Ellman's method and acetylcholinesterase expression was carried out by a semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) assay. We observed that acute (10 and 30 days old rats) and chronic L-tyrosine administration increased acetylcholinesterase activity in serum and all tested brain areas (hippocampus, striatum and cerebral cortex) when compared to control group. Moreover, there was a significant decrease in mRNA levels of acetylcholinesterase in hippocampus was observed after acute protocol (10 and 30 days old rats) and in striatum after chronic protocol. In case these alterations also occur in the brain of the patients, our results may explain, at least in part, the neurological sequelae associated with high plasma concentrations of tyrosine seen in patients affected by tyrosinemia type II.

  1. Acetylcholinesterase assay for cerebrospinal fluid using bupivacaine to inhibit butyrylcholinesterase

    Anders Jens

    2001-12-01

    Full Text Available Abstract Background Most test systems for acetylcholinesterase activity (E.C.3.1.1.7. are using toxic inhibitors (BW284c51 and iso-OMPA to distinguish the enzyme from butyrylcholinesterase (E.C.3.1.1.8. which occurs simultaneously in the cerebrospinal fluid. Applying Ellman's colorimetric method, we were looking for a non-toxic inhibitor to restrain butyrylcholinesterase activity. Based on results of previous in vitro studies bupivacaine emerged to be a suitable inhibitor. Results Pharmacokinetic investigations with purified cholinesterases have shown maximum inhibition of butyrylcholinesterase activity and minimal interference with acetylcholinesterase activity at bupivacaine final concentrations between 0.1 and 0.5 mmol/l. Based on detailed analysis of pharmacokinetic data we developed three equations representing enzyme inhibition at bupivacaine concentrations of 0.1, 0.2 and 0.5 mmol/l. These equations allow us to calculate the acetylcholinesterase activity in solutions containing both cholinesterases utilizing the extinction differences measured spectrophotometrically in samples with and without bupivacaine. The accuracy of the bupivacaine-inhibition test could be confirmed by investigations on solutions of both purified cholinesterases and on samples of human cerebrospinal fluid. If butyrylcholinesterase activity has to be assessed simultaneously an independent test using butyrylthiocholine iodide as substrate (final concentration 5 mmol/l has to be conducted. Conclusions The bupivacaine-inhibition test is a reliable method using spectrophotometrical techniques to measure acetylcholinesterase activity in cerebrospinal fluid. It avoids the use of toxic inhibitors for differentiation of acetylcholinesterase from butyrylcholinesterase in fluids containing both enzymes. Our investigations suggest that bupivacaine concentrations of 0.1, 0.2 or 0.5 mmol/l can be applied with the same effect using 1 mmol/l acetylthiocholine iodide as substrate.

  2. Ketamine protects acetylcholinesterase against inhibition by propoxur and phoxim.

    Koutsoviti-Papadopoulou, M; Kounenis, G; Elezoglou, V

    1994-01-01

    In the present study the effect of ketamine on the contractions caused by propoxur and phoxim on the isolated guinea pig ileum was investigated. Ketamine was found able to inhibit in a concentration-dependent manner the contractile responses of the ileum to propoxur and phoxim, while it did not significantly modify the contractions induced by acetylcholine. Propoxur and phoxim augmented the contractile responses induced by acetylcholine in the presence of acetylcholinesterase. This augmentation was prevented by ketamine, in a concentration-dependent manner. These findings suggest that ketamine inhibits the contractile effect of propoxur and phoxim on the guinea pig ileum and this inhibition seems to be associated with the protection of acetylcholinesterase against the action of these two compounds.

  3. Acupuncture on Gnosia and Acetylcholinesterase in Senile Dementia Patients

    TANG Yong; YU Shu-guang; CHEN Jin; ZHANG Wei

    2003-01-01

    Purpose To observe the effect of acupuncture on gnosia and acetylcholinesterase in patients with senile dementia. Methods Eight patients diagnosed with mild or moderate senile dementia were treated by acupuncture of Sishencong ( Ex-HN 1 ), Shenmen ( HT 7) and Taixi ( KI 3) for I month; gnosia was evaluated by Mini-mental state examination before and after the treatment; plasma acetylcholin esterase activity was measured by flourier before and after the treatment. Results There was a significant difference in gnosia between pre- and post--treatment with acupuncture (P<0.01); there was no significant difference in acetyl- cholinesterase activity between pre- and posttreatment ( P>0.05 ). Conclusion Acupuncture has a certain improving effect on gnosia in senile dementia;one month's acupuncture treatment had little effect on plasma acetyl-cholinesterase activity.

  4. Acetylcholinesterase activity in the cerebrospinal fluid of dogs with seizures.

    Chai, Orit; Sommer, Adi; Zimmerman, Gabriel; Soreq, Hermona; Friedman, Alon; Bdolah-Abram, Tali; Aroch, Itamar; Shamir, Merav H

    2013-10-01

    Recent studies in animal models have focused on the role of cholinergic elements, mainly acetylcholinesterase (AChE) and the 'readthrough' acetylcholinesterase isoform (AChE-R), in seizures. A prospective double-masked study was conducted to assess the activity of AChE and AChE-R in cerebrospinal fluid (CSF) of 26 dogs post-seizure, 28 dogs with intervertebral disc disease (IVDD) and 16 healthy dogs. AChE was also measured in the serum in the post-seizure and IVDD groups. The results showed no significant differences in CSF AChE among the three groups. AChE-R was not detected in any dog and AChE in the serum was similar between groups. This preliminary study provides new information on AChE and AChE-R in the CSF and sera of dogs following naturally-occurring seizures.

  5. Synthesis and Biological Evaluation of Thiophene Derivatives as Acetylcholinesterase Inhibitors

    Mai A. Galal

    2012-06-01

    Full Text Available A series of new thiophene derivatives has been synthesized using the Gewald protocol. The acetylcholinesterase inhibition activity was assayed according to Ellman’s method using donepezil as reference. Some of the compounds were found to be more potent inhibitors than the reference. 2-(2-(4-(4-Methoxyphenylpiperazin-1-ylacetamido-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxamide (IIId showed 60% inhibition, compared to only 40% inhibition by donepezil.

  6. The effect of acetylcholine on the ultrastructure of torpedo acetylcholinesterases

    Feng-chanCHEN; Ying-geZHANG

    2004-01-01

    AIM: To observe the effects of acetylcholine (ACh), the natural substrate of acetylcholinesterases (ACHE), on the conformational state of the active gorge of ACHE. METHODS: Atomic force microscopy (AFM). RESULTS: The surface of the enzyme particles was smooth. The boundary of them was clear and the shapes were ellipsoid. However, the morphology of the enzyme after reacted with ACh became almost utterly different. The most obvious change was a hole or a gorge emerged in the protein,

  7. Ethnic differences in acetylcholinesterase inhibitor use for Alzheimer disease

    Mehta, Kala M; Yin, Maggie; Resendez, Cynthia; Yaffe, Kristine

    2005-01-01

    Acetylcholinesterase inhibitors (AChIs) have been demonstrated to improve Alzheimer disease symptoms. Whether the use of AChIs varies by ethnicity is unknown. More than 2500 ethnically diverse patients (6% African American, 14% Latino, and 7% Asian patients) from the Alzheimer's Disease Research Centers in California were studied. Compared with white patients with AD, minority patients had 40% lower odds of AChI use (odds ratio 0.6, 95% confidence interval: 0.5 to 0.7).

  8. Ethnic differences in acetylcholinesterase inhibitor use for Alzheimer disease.

    Mehta, Kala M; Yin, Maggie; Resendez, Cynthia; Yaffe, Kristine

    2005-07-12

    Acetylcholinesterase inhibitors (AChIs) have been demonstrated to improve Alzheimer disease symptoms. Whether the use of AChIs varies by ethnicity is unknown. More than 2500 ethnically diverse patients (6% African American, 14% Latino, and 7% Asian patients) from the Alzheimer's Disease Research Centers in California were studied. Compared with white patients with AD, minority patients had 40% lower odds of AChI use (odds ratio 0.6, 95% confidence interval: 0.5 to 0.7).

  9. Pyridine alkaloids from Senna multijuga as acetylcholinesterase inhibitors.

    Francisco, Welington; Pivatto, Marcos; Danuello, Amanda; Regasini, Luis O; Baccini, Luciene R; Young, Maria C M; Lopes, Norberto P; Lopes, João L C; Bolzani, Vanderlan S

    2012-03-23

    As part of an ongoing research project on Senna and Cassia species, five new pyridine alkaloids, namely, 12'-hydroxy-7'-multijuguinol (1), 12'-hydroxy-8'-multijuguinol (2), methyl multijuguinate (3), 7'-multijuguinol (4), and 8'-multijuguinol (5), were isolated from the leaves of Senna multijuga (syn. Cassiamultijuga). Their structures were elucidated on the basis of spectroscopic data analysis. Mass spectrometry was used for confirmation of the positions of the hydroxy groups in the side-chains of 1, 2, 4, and 5. All compounds exhibited weak in vitro acetylcholinesterase inhibitory activity as compared with the standard compound physostigmine.

  10. Pd(II complexes of acetylcholinesterase reactivator obidoxime

    Nedzhib Ahmed

    2014-09-01

    Full Text Available The ability of the acetylcholinesterase reactivator obidoxime (H2L2+ to bind palladium(II cations was evaluated spectrophotometrically at different reaction conditions (pH, reaction time, metal-to-ligand molar ratio. The results showed that immediately after mixing the reagents, pH 7.4, complex species of composition [PdHL]3+ existed predominantly with a value of conditional stability constant lgβ'=6.52. The reaction was completed within 24 hours affording the formation of species [Pd2L]4+ with significantly increased stability (lgβ'=9.34. The spectral data suggest that obidoxime coordinates metal(II ions through the oximate functional groups. The in vitro reactivation assay of paraoxon-inhibited rat brain acetylcholinesterase revealed that the new complex species were much less active than the non-coordinated obidoxime. The lack of reactivation ability could be explained by the considerable stability of complexes in solution as well as by the deprotonation of oxime groups essential for recovery of the enzymatic activity.

  11. ACETYLCHOLINESTERASE INHIBITION ACTIVITY OF SOME QUINOLINYL SUBSTITUTED TRIAZOLOTHIADIAZOLE DERIVATIVES.

    Rafiq, Muhammad; Abbas, Qamar; Saleem, Muhammad; Hanif, Muhammad; Lee, Ki Hwan; Seo, Sung-Yum

    2015-01-01

    A series of aralkanoic acids was converted into aralkanoic acid hydrazides through their esters formation. The aralkanoic acid hydrazides upon treatment with carbon disulfide and methanolic potassium hydroxide yielded potassium dithiocarbazinate salts, which on refluxing with aqueous hydrazine hydrate yielded 5-aralkyl-4-amino-3-mercapto-1,2,4-triazoles. The target compounds, 3-aralkyl-6-(substitutedquinolinyl)[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles, were synthesized by condensing various quinolinyl substituted carboxylic acids with 5-aralkyl-4-amino-3-mercapto-1,2,4-triazoles in phosphorus oxychloride. The structures of the newly synthesized triazolothiadiazoles were characterized by IR, 1H NMR, 13C NMR, and elemental analysis studies. The structure of one of the 5-aralkyl-4-amino-3-mercapto-1,2,4-triazoles was unambiguously deduced by single crystal X-ray diffraction analysis. All the synthesized compounds were screened for their acetylcholinesterase inhibition activities. Four of the triazolothiadiazoles exhibited excellent acetylcholinesterase inhibition activities as compared to the reference inhibitor.

  12. Antioxidant Activity and Acetylcholinesterase Inhibition of Grape Skin Anthocyanin (GSA

    Mehnaz Pervin

    2014-07-01

    Full Text Available We aimed to investigate the antioxidant and acetylcholinesterase inhibitory activities of the anthocyanin rich extract of grape skin. Grape skin anthocyanin (GSA neutralized free radicals in different test systems, such as 2,-2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS and 2,2-diphenyl-1-picrylhydrazyl (DPPH assays, to form complexes with Fe2+ preventing 2,2'-azobis(2-amidinopropane dihydrochloride (AAPH-induced erythrocyte hemolysis and oxidative DNA damage. Moreover, GSA decreased reactive oxygen species (ROS generation in isolated mitochondria thus inhibiting 2',-7'-dichlorofluorescin (DCFH oxidation. In an in vivo study, female BALB/c mice were administered GSA, at 12.5, 25, and 50 mg per kg per day orally for 30 consecutive days. Herein, we demonstrate that GSA administration significantly elevated the level of antioxidant enzymes in mice sera, livers, and brains. Furthermore, GSA inhibited acetylcholinesterase (AChE in the in vitro assay with an IC50 value of 363.61 µg/mL. Therefore, GSA could be an excellent source of antioxidants and its inhibition of cholinesterase is of interest with regard to neurodegenerative disorders such as Alzheimer’s disease.

  13. Synthesis of New Indole Derivatives Structurally Related to Donepezil and Their Biological Evaluation as Acetylcholinesterase Inhibitors

    Samar I. Faggal

    2012-04-01

    Full Text Available New series of indole derivatives analogous to donepezil, a well known anti-Alzheimer and acetylcholinesterase inhibitor drug, was synthesized. A full chemical characterization of the new compounds is provided. Biological evaluation of the new compounds as acetylcholinesterase inhibitors was performed. Most of the compounds were found to have potent acetylcholinesterase inhibitor activity compared to donepezil as standard. The compound 1-(2-(4-(2-fluorobenzyl piperazin-1-ylacetylindoline-2,3-dione (IIId was found to be the most potent.

  14. Control levels of acetylcholinesterase expression in the mammalian skeletal muscle.

    Grubic, Z; Zajc-Kreft, K; Brank, M; Mars, T; Komel, R; Miranda, A F

    1999-05-14

    Protein expression can be controled at different levels. Understanding acetylcholinesterase (EC. 3.1.1.7, AChE) expression in the living organisms therefore necessitates: (1) determination and mapping of control levels of AChE metabolism; (2) identification of the regulatory factors acting at these levels; and (3) detailed insight into the mechanisms of action of these factors. Here we summarize the results of our studies on the regulation of AChE expression in the mammalian skeletal muscle. Three experimental models were employed: in vitro innervated human muscle, mechanically denervated adult fast rat muscle, and the glucocorticoid treated fast rat muscle. In situ hybridization of AChE mRNA, combined with AChE histochemistry, revealed that different distribution patterns of AChE, observed during in vitro ontogenesis and synaptogenesis of human skeletal muscle, reflect alterations in the distribution of AChE mRNA (Z. Grubic, R. Komel, W.F. Walker, A.F. Miranda, Myoblast fusion and innervation with rat motor nerve alter the distribution of acetylcholinesterase and its mRNA in human muscle cultures, Neuron 14 (1995) 317-327). To study the mechanisms of AChE mRNA loss in denervated adult rat skeletal muscle, we exposed deproteinated AChE mRNA to various subcellular fractions in vitro. Fractions were isolated from the normal and denervated rat sternomastoideus muscle. We found significantly increased, but non-specific AChE mRNA degradation capacities in the three fractions studied, suggesting that increased susceptibility of muscle mRNA to degradation might be at least partly responsible for the decreased AChE mRNA observed under such conditions (K. Zajc-Kreft, S. Kreft, Z. Grubic, Degradation of AChE mRNA in the normal and denervated rat skeletal muscle, Book of Abstracts, The Sixth International Meeting on Cholinesterases, La Jolla, CA, March 20-24, 1998, p. A3.). In adult fast rat muscle, treated chronically with glucocorticoids, we found the fraction of early

  15. Acetylcholinesterase biosensor for carbaryl detection based on interdigitated array microelectrodes.

    Gong, Zhili; Guo, Yemin; Sun, Xia; Cao, Yaoyao; Wang, Xiangyou

    2014-10-01

    In this study, an acetylcholinesterase (AChE) biosensor with superior accuracy and sensitivity was successfully developed based on interdigitated array microelectrodes (IAMs). IAMs have a series of parallel microband electrodes with alternating microbands connected together. Chitosan was used as the enzyme immobilization material, and AChE was used as the model enzyme for carbaryl detection to fabricate AChE biosensor. Electrochemical impedance spectroscopy was used in conjunction with the fabricated biosensor to detect pesticide residues. Based on the inhibition of pesticides on the AChE activity, using carbaryl as model compounds, the biosensor exhibited a wide range, low detection limit, and high stability. Moreover, the biosensor can also be used as a new promising tool for pesticide residue analysis.

  16. Acetylcholinesterase inhibitory properties of some benzoic acid derivatives

    Yildiz, Melike; Kiliç, Deryanur; Ünver, Yaǧmur; Şentürk, Murat; Askin, Hakan; Küfrevioǧlu, Ömer Irfan

    2016-04-01

    Acetylcholinesterase (AChE) hydrolyses the neurotransmitter acetylcholine to acetic acid and choline. AChE inhibitors are used in treatment of several neurodegeneartive disorder and Alzheimer's disease. In the present study, inhibition of AChE with some benzoic acid derivatives were investigated. 3-Chloro-benzoic acid (1), 2-hydroxy-5-sulfobenzoic acid (2), 2-(sulfooxy) benzoic acid (3), 2-hydroxybenzoic acid (4), 2,3-dimethoxybenzoic (5), and 3,4,5-trimethoxybenzoic (6) were calculated IC50 values AChE enzyme. Kinetic investigations showed that similarly to AChE inhibitors. Benzoic acid derivatives (1-6) investigated are encouraging agents which may be used as lead molecules in order to derivative novel AChE inhibitors that might be useful in medical applications.

  17. Copper, aluminum, iron and calcium inhibit human acetylcholinesterase in vitro.

    Pohanka, Miroslav

    2014-01-01

    Acetylcholinesterase (AChE) is an important part of cholinergic nerves where it participates in termination of neurotransmission. AChE can be inhibited by e.g. some Alzheimer disease drugs, nerve agents, and secondary metabolites. In this work, metal salts aluminum chloride, calcium chloride, cupric chloride, ferric chloride, potassium chloride, magnesium chloride and sodium chloride were tested for their ability to inhibit AChE. Standard Ellman assay based on human recombinant AChE was done and inhibition was measured using Dixon plot. No inhibition was proved for sodium, potassium and magnesium ions. However, aluminum, cupric, ferric and calcium ions were able to inhibit AChE via noncompetitive mechanism of inhibition. Though the inhibition is much weaker when compared to e.g. drugs with noncompetitive mechanism of action, biological relevance of the findings can be anticipated.

  18. Comedication and Treatment Length in Users of Acetylcholinesterase Inhibitors

    Anne Sverdrup Efjestad

    2017-02-01

    Full Text Available Background/Aims: Reduced clinical effect on cognitive decline in dementia by acetylcholinesterase inhibitors (AChEIs may be due to concurrent use of drugs with anticholinergic properties. The aim was to analyze the incidence of AChEI use and comedication with drugs with anticholinergic properties and other potential unfavorable effects. Methods: A prospective study applying drug use data from the Norwegian Prescription Database. Anticholinergic Drug Scale (ADS scores were used as a measure of overall anticholinergic burden. Results: Patients with high ADS scores were more frequently discontinuing treatment early. Coprescribing of antipsychotics was strongly associated with early discontinuation of AChEI treatment. Conclusion: Coprescribing with potentially unfavorable medications was common. A high ADS score was associated with early discontinuation of treatment.

  19. High Efficiency Acetylcholinesterase Immobilization on DNA Aptamer Modified Surfaces

    Orada Chumphukam

    2014-04-01

    Full Text Available We report here the in vitro selection of DNA aptamers for electric eel acetylcholinesterase (AChE. One selected aptamer sequence (R15/19 has a high affinity towards the enzyme (Kd = 157 ± 42 pM. Characterization of the aptamer showed its binding is not affected by low ionic strength (~20 mM, however significant reduction in affinity occurred at high ionic strength (~1.2 M. In addition, this aptamer does not inhibit the catalytic activity of AChE that we exploit through immobilization of the DNA on a streptavidin-coated surface. Subsequent immobilization of AChE by the aptamer results in a 4-fold higher catalytic activity when compared to adsorption directly on to plastic.

  20. Acetylcholinesterase inhibitory effect of lignans isolated from Schizandra chinensis.

    Hung, Tran Manh; Na, MinKyun; Min, Byung Sun; Ngoc, Tran Minh; Lee, IkSoo; Zhang, XinFeng; Bae, KiHwan

    2007-06-01

    The hexane extract of the fruit of Schizandra chinensis (Schisandraceae) was found to show significant inhibition of the activity of acetylcholinesterase enzyme (AChE). In further studies, fourteen lignans were isolated, and evaluated for their inhibitory effect on AChE. The compounds having both aromatic methylenedioxy and hydroxyl groups on their cyclooctadiene ring, such as gomisin C (6), gomisin G (7), gomisin D (8), schisandrol B (11) and gomisin A (13), entirely inhibited AChE in dose dependent manners, with IC50 values of 6.71 +/- 0.53, 6.55 +/- 0.31, 7.84 +/- 0.62, 12.57 +/- 1.07 and 13.28 +/- 1.68 microM, respectively. These results indicate that the lignans could potentially be a potent class of AChE inhibitors.

  1. Carbamate and Organophosphorus Nematicides: Acetylcholinesterase inhibition and Effects on Dispersal.

    Pree, D J; Townshend, J L; Archibald, D E

    1989-10-01

    The sensitivities of acetylcholinesterases (ACHE) from the fungus-feeder Aphelenchus avenae and the plant-parasitic species Helicotylenchus dihystera and Pratylenchus penetrans and the housefly, Musca domestica, were compared using a radiometric assay which utilized H(3) acetylcholine as a substrate. Nematode ACHE were generally less sensitive to inhibition by organophosphorns and carbamate pesticides than were ACHE from the housefly. ACHE from the plant-parasitic species and A. avenae were generally similar in sensitivity. In soil, carbamates were more toxic than the organophosphorus pesticides to A. avenae. All pesticides tested affected nematode movement, but fenamiphos was more inhibitory than others. The effects on dispersal of nematodes may be an important mechanism in control by some nematicides.

  2. Tissue distribution of human acetylcholinesterase and butyrylcholinesterase messenger RNA

    Jbilo, O.; Barteles, C.F.; Chatonnet, A.; Toutant, J.P.; Lockridge, O.

    1994-12-31

    Tissue distribution of human acetyicholinesterase and butyryicholinesterase messenger RNA. 1 Cholinesterase inhibitors occur naturally in the calabar bean (eserine), green potatoes (solanine), insect-resistant crab apples, the coca plant (cocaine) and snake venom (fasciculin). There are also synthetic cholinesterase inhibitors, for example man-made insecticides. These inhibitors inactivate acetyicholinesterase and butyrylcholinesterase as well as other targets. From a study of the tissue distribution of acetylcholinesterase and butyrylcholinesterase mRNA by Northern blot analysis, we have found the highest levels of butyrylcholinesterase mRNA in the liver and lungs, tissues known as the principal detoxication sites of the human body. These results indicate that butyrylcholinesterase may be a first line of defense against poisons that are eaten or inhaled.

  3. Preclinical and first-in-human evaluation of PRX-105, a PEGylated, plant-derived, recombinant human acetylcholinesterase-R

    Atsmon, Jacob [Clinical Research Center, Tel Aviv Sourasky Medical Center, Tel Aviv (Israel); Sackler Faculty of Medicine, Tel Aviv University (Israel); Brill-Almon, Einat; Nadri-Shay, Carmit; Chertkoff, Raul; Alon, Sari [Protalix Biotherapeutics, Science Park, Carmiel (Israel); Shaikevich, Dimitri; Volokhov, Inna; Haim, Kirsten Y. [Clinical Research Center, Tel Aviv Sourasky Medical Center, Tel Aviv (Israel); Sackler Faculty of Medicine, Tel Aviv University (Israel); Bartfeld, Daniel [Protalix Biotherapeutics, Science Park, Carmiel (Israel); Shulman, Avidor, E-mail: avidors@protalix.com [Protalix Biotherapeutics, Science Park, Carmiel (Israel); Ruderfer, Ilya; Ben-Moshe, Tehila; Shilovitzky, Orit [Protalix Biotherapeutics, Science Park, Carmiel (Israel); Soreq, Hermona [Department of Biological Chemistry, Institute of Life Sciences, The Hebrew University of Jerusalem (Israel); Shaaltiel, Yoseph [Protalix Biotherapeutics, Science Park, Carmiel (Israel)

    2015-09-15

    PRX-105 is a plant-derived recombinant version of the human ‘read-through’ acetylcholinesterase splice variant (AChE-R). Its active site structure is similar to that of the synaptic variant, and it displays the same affinity towards organophosphorus (OP) compounds. As such, PRX-105 may serve as a bio-scavenger for OP pesticides and chemical warfare agents. To assess its potential use in prophylaxis and treatment of OP poisoning we conducted several preliminary tests, reported in this paper. Intravenous (IV) PRX-105 was administered to mice either before or after exposure to an OP toxin. All mice who received an IV dose of 50 nmol/kg PRX-105, 2 min before being exposed to 1.33 × LD{sub 50} and 1.5 × LD{sub 50} of toxin and 10 min after exposure to 1.5 × LD{sub 50} survived. The pharmacokinetic and toxicity profiles of PRX-105 were evaluated in mice and mini-pigs. Following single and multiple IV doses (50 to 200 mg/kg) no deaths occurred and no significant laboratory and histopathological changes were observed. The overall elimination half-life (t{sub ½}) in mice was 994 (± 173) min. Additionally, a first-in-human study, to assess the safety, tolerability and pharmacokinetics of the compound, was conducted in healthy volunteers. The t{sub ½} in humans was substantially longer than in mice (average 26.7 h). Despite the small number of animals and human subjects who were assessed, the fact that PRX-105 exerts a protective and therapeutic effect following exposure to lethal doses of OP, its favorable safety profile and its relatively long half-life, renders it a promising candidate for treatment and prophylaxis against OP poisoning and warrants further investigation. - Highlights: • PRX-105 is a PEGylated plant-derived recombinant human acetylcholinesterase-R. • PRX-105 is a promising bio-scavenger for organophosphorous toxins at lethal doses. • PRX-105 was shown to protect animals both prophylactically and post-poisoning. • First-in-human study

  4. EEG SPECTRA, BEHAVIORAL STATES AND MOTOR ACTIVITY IN RATS EXPOSED TO ACETYLCHOLINESTERASE INHIBITOR CHLORPYRIFOS.

    Exposure to organophosphate pesticides (OP) has been associated with sleep disorders: insomnia and ?excessive dreaming'. However neuronal mechanisms of these effects have not been analyzed. OP inhibit acetylcholinesterase activity leading to a hyperativity of the brain cholin...

  5. Triterpenoids from Azorella trifurcata (Gaertn.) Pers and their effect against the enzyme acetylcholinesterase

    Areche, Carlos; Cejas, Patricia; Thomas, Pablo; San-Martin, Aurelio [University of Chile, Santiago (Chile). Faculty of Sciences. Dept. of Chemistry], e-mail: aurelio@uchile.cl; Astudillo, Luis; Gutierrez, Margarita [University of Talca, Talca (Chile). Inst. of Chemistry of Natural Resource; Loyola, Luis A. [University of Antofagasta (Chile). Faculty of Basic Sciences. Dept. of Chemistry

    2009-07-01

    The inhibition of the enzyme acetylcholinesterase is considered as a strategy for the treatment of Alzheimer's disease, senile dementia, ataxia, and myasthenia gravis. Three lanostane- and two cycloartane-type triterpenes, together with two mulinane-type diterpenes were isolated from petroleum ether extract of the whole shrub of Azorella trifurcata (Gaertn.) Pers. Their effect on the enzyme acetylcholinesterase was assessed as well. In addition, this is the first report of these triterpenes in the genus Azorella. (author)

  6. Acetylcholinesterase-Based Electrochemical Multiphase Microreactor for Detection of Organophosphorous Compounds (Preprint)

    2007-04-01

    microchannel /membrane reactor allows for fast diffusion of a concentrated vapor into the liquid microchannel and lowers the detection limit and...use, modify, reproduce, release, perform, display, or disclose the work by or on behalf of the U. S. Government. 14. ABSTRACT A dual microchannel ...acetylcholinesterase inhibition. Electric eel acetylcholinesterase was immobilized on the liquid microchannel by creating a cross-linked gel with

  7. Triterpenoids from Azorella trifurcata (Gaertn. Pers and their effect against the enzyme acetylcholinesterase

    Carlos Areche

    2009-01-01

    Full Text Available The inhibition of the enzyme acetylcholinesterase is considered as a strategy for the treatment of Alzheimer's disease, senile dementia, ataxia, and myasthenia gravis. Three lanostane- and two cycloartane-type triterpenes, together with two mulinane-type diterpenes were isolated from petroleum ether extract of the whole shrub of Azorella trifurcata (Gaertn. Pers. Their effect on the enzyme acetylcholinesterase was assessed as well. In addition, this is the first report of these triterpenes in the genus Azorella.

  8. Assay of Acetylcholinesterase Activity and Electrochemical Determination of Fenthion in Oil-in-water Emulsion

    Sun Kai; He JingJing; Miao YuQing

    2009-01-01

    @@ Organophosphates (OPs) have been widely used as pesticides,insecticides or even chemical warfare agents.Acetylcholinesterase (ACHE) inhibition has been employed to develop verious assay methods for detection of pesticides with the advantages of low cost,simple procedure and quick assay time.The study of acetylcholinesterase (ACHE) activity and OPs inhibition in the solution containing organic solvent is extremely important owing to poor solubility of Ops in water and a higher solubility in organic solvents.

  9. The Effect of Parathion on Red Blood Cell Acetylcholinesterase in the Wistar Rat

    Naofumi Bunya

    2016-01-01

    Full Text Available Organophosphorus (OP pesticide poisoning is a significant problem worldwide. Research into new antidotes for these acetylcholinesterase inhibitors, and even optimal doses for current therapies, is hindered by a lack of standardized animal models. In this study, we sought to characterize the effects of the OP pesticide parathion on acetylcholinesterase in a Wistar rat model that included comprehensive medical care. Methods. Male Wistar rats were intubated and mechanically ventilated and then poisoned with between 20 mg/kg and 60 mg/kg of intravenous parathion. Upon developing signs of poisoning, the rats were treated with standard critical care, including atropine, pralidoxime chloride, and midazolam, for up to 48 hours. Acetylcholinesterase activity was determined serially for up to 8 days after poisoning. Results. At all doses of parathion, maximal depression of acetylcholinesterase occurred at 3 hours after poisoning. Acetylcholinesterase recovered to nearly 50% of baseline activity by day 4 in the 20 mg/kg cohort and by day 5 in the 40 and 60 mg/kg cohorts. At day 8, most rats’ acetylcholinesterase had recovered to roughly 70% of baseline. These data should be useful in developing rodent models of acute OP pesticide poisoning.

  10. Structure-activity approach in the reactivation of tabun-phosphorylated human acetylcholinesterase with bispyridinium para-aldoximes.

    Kovarik, Zrinka; Calić, Maja; Sinko, Goran; Bosak, Anita

    2007-06-01

    We investigated interactions of bispyridinium para-aldoximes N,N'-(propano)bis(4-hydroxyiminomethyl) pyridinium bromide (TMB-4), N,N'-(ethano)bis(4-hydroxyiminomethyl)pyridinium methanosulphonate (DMB-4), and N,N'-(methano)bis(4-hydroxyiminomethyl)pyridinium chloride (MMB-4) with human erythrocyte acetylcholinesterase phosphorylated by tabun. We analysed aldoxime conformations to determine the flexibility of aldoxime as an important feature for binding to the acetylcholinesterase active site. Tabun-inhibited human erythrocyte acetylcholinesterase was completely reactivated only by the most flexible bispyridinium aldoxime - TMB-4 with a propylene chain between two rings. Shorter linkers than propylene (methylene or ethylene) as in MMB-4 and DMB-4 did not allow appropriate orientation in the active site, and MMB-4 and DMB-4 were not efficient reactivators of tabun-phosphorylated acetylcholinesterase. Since aldoximes are also reversible inhibitors of native acetylcholinesterase, we determined dissociation constants and their protective index against acetylcholinesterase inactivation by tabun.

  11. N-acetylcholinesterase-induced apoptosis in Alzheimer's disease.

    Debra Toiber

    Full Text Available BACKGROUND: Alzheimer's disease (AD involves loss of cholinergic neurons and Tau protein hyper-phosphorylation. Here, we report that overexpression of an N-terminally extended "synaptic" acetylcholinesterase variant, N-AChE-S is causally involved in both these phenomena. METHODOLOGY AND PRINCIPAL FINDINGS: In transfected primary brain cultures, N-AChE-S induced cell death, morphological impairments and caspase 3 activation. Rapid internalization of fluorescently labeled fasciculin-2 to N-AChE-S transfected cells indicated membranal localization. In cultured cell lines, N-AChE-S transfection activated the Tau kinase GSK3, induced Tau hyper-phosphorylation and caused apoptosis. N-AChE-S-induced cell death was suppressible by inhibiting GSK3 or caspases, by enforced overexpression of the anti-apoptotic Bcl2 proteins, or by AChE inhibition or silencing. Moreover, inherent N-AChE-S was upregulated by stressors inducing protein misfolding and calcium imbalances, both characteristic of AD; and in cortical tissues from AD patients, N-AChE-S overexpression coincides with Tau hyper-phosphorylation. CONCLUSIONS: Together, these findings attribute an apoptogenic role to N-AChE-S and outline a potential value to AChE inhibitor therapeutics in early AD.

  12. ACETYLCHOLINESTERASE LEVELS IN FARMERS EXPOSED TO PESTICIDES IN MALAYSIA

    Ismarulyusda Ishak

    2015-11-01

    Full Text Available Agriculture is an important component of the Malaysian economy. Pesticides are widely used by farmers to increase crop production. Acetylcholinesterase (AChE is known to play an important role in the degradation of acetylcholine (ACh at the neuromuscular junction of the nervous system. The purpose of this study was to determine the effect of pesticide exposure on serum levels of AChE of farmers. A cross-sectional study was conducted. A total of 95 farmers from Kelantan (n = 49 and Selangor (n = 46 aged between 23 and 71 years were recruited. AChE concentration was measured by spectrophotometry. The results of this study showed that the mean AChE concentrations in farmers from Kelantan and Selangor were 2,715 and 2,660 U/L, respectively, significantly different (p < 0.05 from normal reference value (3500 U/l. Pearson correlation test showed a moderate correlation betweenAChE level and age (r = -0.551 and a strong correlation between AChE level and working period (r = -0.872 in farmers in Kelantan. AChE levels in Selangor were also moderately correlated with age (r = -0.353 and working period (r = -0.515. In conclusion, increasing age and long-term pesticide exposure reduce AChE levels in farmers.

  13. QSAR study of acetylcholinesterase inhibitors for Alzheimer’s disease

    Somaye Setakeh

    2016-06-01

    Full Text Available Alzheimer’s disease (AD is an incapacitating neurodegenerative disease that slowly destroys brain cells. This disease progressively compromises both memory and cognition, culminating in a state of full dependence and dementia. Currently, AD is the main cause of dementia in the elderly and its prevalence in the developed world is increasing rapidly. Classic drugs, such as acetylcholinesterase inhibitors (AChEIs, fail to decline disease progression and display several side effects that reduce patient’s adhesion to pharmacotherapy. The past decade has witnessed an increasing focus on the search for novel AChEIs and new putative enzymatic targets for AD, like β –and γ -secretases, sirtuins, caspase proteins and glycogen syntheses kinase-3 (GSK-3. Genetic algorithm (GA, artificial neural network (ANN, Imperialist Competitive Algorithm (ICA, multiple linear regression (MLR, was used to create QSAR models. According to the obtained results, GA-ANN model was the most favorable method toward the other statistical methods. For this purpose, ab initio geometry optimization was performed at B3LYP level with a known basis set at 6-31G(d. R and R2 values of the GA-stepwise MLR model were obtained as 0.89 and 0.80.

  14. Electroanalysis of amino acid substitutions in bioengineered acetylcholinesterase.

    Somji, Mehdi; Dounin, Vladimir; Muench, Susanne B; Schulze, Holger; Bachmann, Till T; Kerman, Kagan

    2012-12-01

    This study reports the electrochemical profiling of Nippostrongylus brasiliensis acetylcholinesterase (AChE) wild-type and mutant proteins. An irreversible oxidation signal of electro-active tyrosine (Y), tryptophan (W) and cysteine (C) residues in five mutant proteins along with the wild-type AChE were detected using square-wave voltammetry (SWV) on screen-printed carbon electrodes. Significant differences were observed in the W303L, T65Y and M301W substituted proteins showing a 25-35% higher peak current intensity compared to the Y349Y and F345Y mutants. It was predicted that AChE substituted with electrochemically active residues would produce the greatest signals and this trend was observed in the T65Y, M301W and Y349L mutants. However, conformational changes in the proteins structure as a result of the substitutions appeared to be most influential on peak current intensities. This was demonstrated by the W303L and F345Y mutant enzymes. The current intensity of W303L was greatest despite the removal of its electro-active W residue whereas the F345Y mutant had the lowest peak value despite the addition of an electro-active Y residue. The preliminary results of this study demonstrate that SWV provides a promising tool to probe the presence of electro-active amino acid residues on the surface of a protein produced through bioengineering.

  15. Are soluble and membrane-bound rat brain acetylcholinesterase different

    Andres, C.; el Mourabit, M.; Stutz, C.; Mark, J.; Waksman, A. (Centre de Neurochimie du C.N.R.S., Strasbourg, (France))

    1990-11-01

    Salt-soluble and detergent-soluble acetylcholinesterases (AChE) from adult rat brain were purified to homogeneity and studied with the aim to establish the differences existing between these two forms. It was found that the enzymatic activities of the purified salt-soluble AChE as well as the detergent-soluble AChE were dependent on the Triton X-100 concentration. Moreover, the interaction of salt-soluble AChE with liposomes suggests amphiphilic behaviour of this enzyme. Serum cholinesterase (ChE) did not bind to liposomes but its activity was also detergent-dependent. Detergent-soluble AChE remained in solution below critical micellar concentrations of Triton X-100. SDS polyacrylamide gel electrophoresis of purified, Biobeads-treated and iodinated detergent-soluble 11 S AChE showed, under non reducing conditions, bands of 69 kD, 130 kD and greater than 250 kD corresponding, respectively, to monomers, dimers and probably tetramers of the same polypeptide chain. Under reducing conditions, only a 69 kD band was detected. It is proposed that an amphiphilic environment stabilizes the salt-soluble forms of AChE in the brain in vivo and that detergent-soluble Biobeads-treated 11 S AChE possess hydrophobic domain(s) different from the 20 kD peptide already described.

  16. Acetylcholinesterase immobilized onto PEI-coated silica nanoparticles.

    Tumturk, Hayrettin; Yüksekdag, Hazer

    2016-01-01

    Polyethyleneimine (PEI) coated-silica nanoparticles were prepared by the Stöber method. The formation and the structure of the nanoparticles were characterized by ATR-FT-IR spectroscopy and transmission electron microscopy (TEM). TEM images of the silica and PEI-coated nanoparticles revealed that they were well dispersed and that there was no agglomeration. The acetylcholineesterase enzyme was immobilized onto these nanoparticles. The effects of pH and temperature on the storage stability of the free and immobilized enzyme were investigated. The optimum pHs for free and immobilized enzymes were determined as 7.0 and 8.0, respectively. The optimum temperatures for free and immobilized enzymes were found to be 30.0 and 35.0°C, respectively. The maximum reaction rate (Vmax) and the Michaelis-Menten constant (Km) were investigated for the free and immobilized enzyme. The storage stability of acetylcholinesterase was increased when immobilized onto the novel PEI-coated silica nanoparticles. The reuse numbers of immobilized enzyme were also studied. These hybrid nanoparticles are desirable as carriers for biomedical applications.

  17. Tacrine derivatives-acetylcholinesterase interaction: 1H NMR relaxation study.

    Delfini, Maurizio; Di Cocco, Maria Enrica; Piccioni, Fabiana; Porcelli, Fernando; Borioni, Anna; Rodomonte, Andrea; Del Giudice, Maria Rosaria

    2007-06-01

    Two acetylcholinesterase (AChE) inhibitors structurally related to Tacrine, 6-methoxytacrine (1a) and 9-heptylamino-6-methoxytacrine (1b), and their interaction with Electrophorus Electricus AChE were investigated. The complete assignment of the 1H and 13C NMR spectra of 1a and 1b was performed by mono-dimensional and homo- and hetero-correlated two-dimensional NMR experiments. This study was undertaken to elucidate the interaction modes between AChE and 1a and 1b in solution, using NMR. The interaction between the two inhibitors and AChE was studied by the analysis of the motional parameters non-selective and selective spin-lattice relaxation times, thereby allowing the motional state of 1a and 1b, both free and bound with AChE, to be defined. The relaxation data pointed out the ligands molecular moiety most involved in the binding with AChE. The relevant ligand/enzyme interaction constants were also evaluated for both compounds and resulted to be 859 and 5412M(-1) for 1a and1b, respectively.

  18. Acute administration of fenproporex increased acetylcholinesterase activity in brain of young rats

    BRENA P. TEODORAK

    2015-08-01

    Full Text Available Fenproporex is the second most commonly amphetamine-based anorectic consumed worldwide; this drug is rapidly converted into amphetamine, in vivo, and acts by increasing dopamine levels in the synaptic cleft. Considering that fenproporex effects on the central nervous system are still poorly known and that acetylcholinesterase is a regulatory enzyme which is involved in cholinergic synapses and may indirectly modulate the release of dopamine, the present study investigated the effects of acute administration of fenproporex on acetylcholinesterase activity in brain of young rats. Young male Wistar rats received a single injection of fenproporex (6.25, 12.5 or 25mg/kg i.p. or vehicle (2% Tween 80. Two hours after the injection, the rats were killed by decapitation and the brain was removed for evaluation of acetylcholinesterase activity. Results showed that fenproporex administration increased acetylcholinesterase activity in the hippocampus and posterior cortex, whereas in the prefrontal cortex, striatum and cerebellum the enzyme activity was not altered. In conclusion, in the present study we demonstrated that acute administration of fenproporex exerts an effect in the cholinergic system causing an increase in the activity of acetylcholinesterase in a dose-dependent manner in the hippocampus and posterior cortex. Thus, we suggest that the imbalance in cholinergic homeostasis could be considered as an important pathophysiological mechanism underlying the brain damage observed in patients who use amphetamines such as fenproporex.

  19. Immobilization of Acetylcholinesterase on Screen-Printed Electrodes. Application to the Determination of Arsenic(III

    M. Julia Arcos-Martínez

    2010-03-01

    Full Text Available Enzymatic amperometric procedures for measuring arsenic, based on the inhibitive action of this metal on acetylcholinesterase enzyme activity, have been developed. Screen-printed carbon electrodes (SPCEs were used with acetylcholinesterase covalently bonded directly to its surface. The amperometric response of acetylcholinesterase was affected by the presence of arsenic ions, which caused a decrease in the current intensity. The experimental optimum working conditions of pH, substrate concentration and potential applied, were established. Under these conditions, repeatability and reproducibility of biosensors were determined, reaching values below 4% in terms of relative standard deviation. The detection limit obtained for arsenic was 1.1 × 10−8 M for Ach/SPCE biosensor. Analysis of the possible effect of the presence of foreign ions in the solution was performed. The method was applied to determine levels of arsenic in spiked tap water samples.

  20. Acetylcholinesterase-inhibitory activities of the extracts from sponges collected in mauritius waters.

    Beedessee, Girish; Ramanjooloo, Avin; Surnam-Boodhun, Rashmee; van Soest, Rob W M; Marie, Daniel E P

    2013-03-01

    Patients diagnosed with Alzheimer's disease (AD) show a characteristic neurochemical deficit of acetylcholine, especially in the basal forebrains. The use of acetylcholinesterase (AChE) inhibitors to retard the hydrolysis of acetylcholine has been suggested as a promising strategy for AD treatment. In this study, we evaluated the acetylcholinesterase inhibitory (AChEI) activities of 134 extracts obtained from 45 species of marine sponges. Thin-layer chromatography (TLC) and microplate assays reveal potent acetylcholinsterase inhibitory activities of two AcOEt extracts from the sponges Pericharax heteroraphis and Amphimedon navalis PULITZER-FINALI. We further investigated the inhibitory kinetics of the extracts and found them to display mixed competitive/noncompetitive inhibition and associated their inhibitory activity partly to terpenoids. Acetylcholinesterase inhibitors from marine organisms have been rarely studied, and this study demonstrated the potential of marine sponges as a source of pharmaceutical leads against neurodegenerative diseases.

  1. A novel biosensor method for surfactant determination based on acetylcholinesterase inhibition

    Kucherenko, I. S.; Soldatkin, O. O.; Arkhypova, V. M.; Dzyadevych, S. V.; Soldatkin, A. P.

    2012-06-01

    A novel enzyme biosensor based on acetylcholinesterase inhibition for the determination of surfactants in aqueous solutions is described. Acetylcholinesterase-based bioselective element was deposited via glutaraldehyde on the surface of conductometric transducers. Different variants of inhibitory analysis of surfactants were tested, and finally surfactant's concentration was evaluated by measuring initial rate of acetylcholinesterase inhibition. Besides, we studied the effect of solution characteristics on working parameters of the biosensor for direct measurement of acetylcholine and for inhibitory determination of surfactants. The biosensor's sensitivity to anionic and cationic surfactants (0.35 mg l-1) was tested. The high operational stability of the biosensor during determination of acetylcholine (RSD 2%) and surfactants (RSD 11%) was shown. Finally, we discussed the selectivity of the biosensor toward surfactants and other AChE inhibitors. The proposed biosensor can be used as a component of the multibiosensor for ecological monitoring of toxicants.

  2. Quality control evaluation and acetylcholinesterase inhibitory activity of Galanthus woronowii Losinsk

    Ahmet Emir

    2011-05-01

    Full Text Available Aerial and underground parts ofGalanthus woronowiiLosinsk., a wild growingspecies in north-eastern Anatolia, were collected during flowering period. Quality controland acetylcholinesterase inhibitory activity determinations were carried out on Bulbus andHerba Galanthi prepared from plants collected from two different localities. In the context ofquality control studies, contents of humidity, total ash, sulphated ash, acid-insoluble ash and total alkaloids of the drug specimens were determined and found to range between8.463-9.343 %, 6.950-14.947 %, 9.743-17.930 %, 1.102-3.565 % and 0.247-0.499 %, respectively. Additionally, acetylcholinesterase inhibitory activity of the alkaloidal extracts prepared fromthe drug specimens were determined by using Thin Layer Chromatography (TLC combined with a bioautographic assay based onin vitro Ellman method. All of the alkaloidal extractsdisplayed acetylcholinesterase inhibitory activity

  3. Amphiphile dependency of the monomeric and dimeric forms of acetylcholinesterase from human erythrocyte membrane.

    Ott, P; Brodbeck, U

    1984-08-08

    Human erythrocyte membrane-bound acetylcholinesterase was converted to a monomeric species by treatment of ghosts with 2-mercaptoethanol and iodoacetic acid. After solubilization with Triton X-100, the reduced and alkylated enzyme was partially purified by affinity chromatography and separated from residual dimeric enzyme by sucrose density gradient centrifugation in a zonal rotor. Monomeric and dimeric acetylcholinesterase showed full enzymatic activity in presence of Triton X-100 whereas in the absence of detergent, activity was decreased to approx. 20% and 15%, respectively. Preformed egg phosphatidylcholine vesicles fully sustained activity of the monomeric species whereas the dimer was only 80% active. The results suggest that a dimeric structure is not required for manifestation of amphiphile dependency of membrane-bound acetylcholinesterase from human erythrocytes. Furthermore, monomeric enzyme appears to be more easily inserted into phospholipid bilayers than the dimeric species.

  4. Novel acetylcholinesterase target site for malaria mosquito control.

    Yuan-Ping Pang

    Full Text Available Current anticholinesterase pesticides were developed during World War II and are toxic to mammals because they target a catalytic serine residue of acetylcholinesterases (AChEs in insects and in mammals. A sequence analysis of AChEs from 73 species and a three-dimensional model of a malaria-carrying mosquito (Anopheles gambiae AChE (AgAChE reported here show that C286 and R339 of AgAChE are conserved at the opening of the active site of AChEs in 17 invertebrate and four insect species, respectively. Both residues are absent in the active site of AChEs of human, monkey, dog, cat, cattle, rabbit, rat, and mouse. The 17 invertebrates include house mosquito, Japanese encephalitis mosquito, African malaria mosquito, German cockroach, Florida lancelet, rice leaf beetle, African bollworm, beet armyworm, codling moth, diamondback moth, domestic silkworm, honey bee, oat or wheat aphid, the greenbug, melon or cotton aphid, green peach aphid, and English grain aphid. The four insects are house mosquito, Japanese encephalitis mosquito, African malaria mosquito, and German cockroach. The discovery of the two invertebrate-specific residues enables the development of effective and safer pesticides that target the residues present only in mosquito AChEs rather than the ubiquitous serine residue, thus potentially offering an effective control of mosquito-borne malaria. Anti-AgAChE pesticides can be designed to interact with R339 and subsequently covalently bond to C286. Such pesticides would be toxic to mosquitoes but not to mammals.

  5. Can Salivary Acetylcholinesterase be a Diagnostic Biomarker for Alzheimer?

    Bakhtiari, Sedigheh; Moghadam, Nahid Beladi; Ehsani, Marjan; Mortazavi, Hamed; Sabour, Siamak

    2017-01-01

    Introduction The loss of brain cholinergic activity is a key phenomenon in the biochemistry of Alzheimer’s Disease (AD). Due to the specific biosynthesis of Acetylcholinesterase (AChE) of cholinergic neurons, the enzyme has been proposed as a potential biochemical marker of cholinergic activity. AChE is expressed not only in the Central Nervous System (CNS), Peripheral Nervous System (PNS) and muscles, but also on the surface of blood cells and saliva. Aim This study aimed to measure salivary AChE activity in AD and to determine the feasibility of creating a simple laboratory test for diagnosing such patients. Materials and Methods In this cross-sectional study, the recorded data were obtained from 15 Alzheimer’s patients on memantine therapy and 15 healthy subjects. Unstimulated whole saliva samples were collected from the participants and salivary levels of AChE activity were determined by using the Ellman colorimetric method. The Mann Whitney U test was used to compare the average (median) of AChE activity between AD and controls. In order to adjust for possible confounding factors, partial correlation coefficient and multivariate linear regressions were used. Results Although the average of AChE activity in the saliva of people with AD was lower compared to the control group, we found no statistically significant differences using Mann Whitney U test (138 in control group vs. 175 in Alzheimer’s patients, p value=0.25). Additionally, no significant differences were observed in the activity of this enzyme in both sexes or with increased age or duration of the disease. After adjusting for age and gender, there was no association between AChE activity and AD (regression coefficient β=0.08; p value= 0.67). conclusion Saliva AChE activity was not significantly associated with AD. This study might help in introduce a new diagnostic aid for AD or monitor patients with AD.

  6. Comparative effect of pesticides on brain acetylcholinesterase in tropical fish.

    Assis, Caio Rodrigo Dias; Linhares, Amanda Guedes; Oliveira, Vagne Melo; França, Renata Cristina Penha; Carvalho, Elba Veronica Matoso Maciel; Bezerra, Ranilson Souza; de Carvalho, Luiz Bezerra

    2012-12-15

    Monitoring of pesticides based on acetylcholinesterase (AChE; EC 3.1.1.7) inhibition in vitro avoids interference of detoxification defenses and bioactivation of some of those compounds in non-target tissues. Moreover, environmental temperature, age and stress are able to affect specific enzyme activities when performing in vivo studies. Few comparative studies have investigated the inter-specific differences in AChE activity in fish. Screening studies allow choosing the suitable species as source of AChE to detect pesticides in a given situation. Brain AChE from the tropical fish: pirarucu (Arapaima gigas), cobia (Rachycentron canadum) and Nile tilapia (Oreochromis niloticus) were characterized and their activities were assayed in the presence of pesticides (the organophosphates: dichlorvos, diazinon, chlorpyrifos, temephos, tetraethyl pyrophosphate- TEPP and the carbamates: carbaryl and carbofuran). Inhibition parameters (IC₅₀ and Ki) for each species were found and compared with commercial AChE from electric eel (Electrophorus electricus). Optimal pH and temperature were found to be 8.0 and 35-45 °C, respectively. A. gigas AChE retained 81% of the activity after incubation at 50 °C for 30 min. The electric eel enzyme was more sensitive to the compounds (mainly carbofuran, IC₅₀ of 5 nM), excepting the one from A. gigas (IC₅₀ of 9 nM) under TEPP inhibition. These results show comparable sensitivity between purified and non-purified enzymes suggesting them as biomarkers for organophosphorus and carbamate detection in routine environmental and food monitoring programs for pesticides.

  7. Rapid detoxification of benzodiazepine or Z-drugs dependence using acetylcholinesterase inhibitors.

    Lin, Shih-Ku

    2014-07-01

    Dependence on benzodiazepines (BZDs) or Z-drugs (zolpidem, zopicline and zaleplon) is a common clinical phenomenon. Traditional detoxification of BZDs dependence includes tapering used dose gradually and using equivalent doses of long-acting BZDs as substitutes. This kind of regimen tends to take a long time (up to 4weeks) and may require hospitalization. Acetylcholinesterase inhibitors have been shown to reverse BZDs induced sedation. We propose that oral form acetylcholinesterase inhibitors (donepezil, galantamine and rivastigmine) also posses the effect of inhibiting GABA receptors, and act as indirect antagonist, to be applied in the rapid detoxification treatment of BZDs and Z-drug dependence.

  8. Plant-parasitic Nematode Acetylcholinesterase Inhibition by Carbamate and Organophosphate Nematicides.

    Opperman, C H; Chang, S

    1990-10-01

    The sensitivity of acetylcholinesterases (ACHE) isolated from the plant-parasitic nematodes Meloidogyne arenaria, M. incognita, and Heterodera glycines and the free-living nematode Caenorhabditis elegans to carbamate and organophosphate nematicides was examined. The AChE from plant-parasitic nematode species were more sensitive to carbamate inhibitors than was AChE from C. elegans, but response to the organophosphates was approximately equivalent. The sulfur-containing phosphate nematicides were poor inhibitors of nematode acetylcholinesterase, but treatment with an oxidizing agent greatly improved inhibition. Behavioral bioassays with living nematodes revealed a poor relationship between enzyme inhibition and expression of symptoms in live nematodes.

  9. Preclinical and first-in-human evaluation of PRX-105, a PEGylated, plant-derived, recombinant human acetylcholinesterase-R.

    Atsmon, Jacob; Brill-Almon, Einat; Nadri-Shay, Carmit; Chertkoff, Raul; Alon, Sari; Shaikevich, Dimitri; Volokhov, Inna; Haim, Kirsten Y; Bartfeld, Daniel; Shulman, Avidor; Ruderfer, Ilya; Ben-Moshe, Tehila; Shilovitzky, Orit; Soreq, Hermona; Shaaltiel, Yoseph

    2015-09-15

    PRX-105 is a plant-derived recombinant version of the human 'read-through' acetylcholinesterase splice variant (AChE-R). Its active site structure is similar to that of the synaptic variant, and it displays the same affinity towards organophosphorus (OP) compounds. As such, PRX-105 may serve as a bio-scavenger for OP pesticides and chemical warfare agents. To assess its potential use in prophylaxis and treatment of OP poisoning we conducted several preliminary tests, reported in this paper. Intravenous (IV) PRX-105 was administered to mice either before or after exposure to an OP toxin. All mice who received an IV dose of 50nmol/kg PRX-105, 2min before being exposed to 1.33×LD50 and 1.5×LD50 of toxin and 10min after exposure to 1.5×LD50 survived. The pharmacokinetic and toxicity profiles of PRX-105 were evaluated in mice and mini-pigs. Following single and multiple IV doses (50 to 200mg/kg) no deaths occurred and no significant laboratory and histopathological changes were observed. The overall elimination half-life (t½) in mice was 994 (±173) min. Additionally, a first-in-human study, to assess the safety, tolerability and pharmacokinetics of the compound, was conducted in healthy volunteers. The t½ in humans was substantially longer than in mice (average 26.7h). Despite the small number of animals and human subjects who were assessed, the fact that PRX-105 exerts a protective and therapeutic effect following exposure to lethal doses of OP, its favorable safety profile and its relatively long half-life, renders it a promising candidate for treatment and prophylaxis against OP poisoning and warrants further investigation.

  10. Monooxime reactivators of acetylcholinesterase with (E)-but-2-ene linker: preparation and reactivation of tabun- and paraoxon-inhibited acetylcholinesterase.

    Musilek, Kamil; Holas, Ondrej; Jun, Daniel; Dohnal, Vlastimil; Gunn-Moore, Frank; Opletalova, Veronika; Dolezal, Martin; Kuca, Kamil

    2007-11-01

    Acetylcholinesterase reactivators are crucial antidotes for the treatment of organophosphate intoxication. Fifteen new monooxime reactivators of acetylcholinesterase with a (E)-but-2-ene linker were developed in an effort to extend the properties of K-oxime (E)-1-(4-carbamoylpyridinium)-4-(4-hydroxyiminomethylpyridinium)-but-2-ene dibromide (K203). The known reactivators (pralidoxime, HI-6, obidoxime, K075, K203) and the new compounds were tested in vitro on a model of tabun- and paraoxon-inhibited AChE. Monooxime reactivators were not able to exceed the best known compounds for tabun poisoning, but some of them did show reactivation comparable with known compounds for paraoxon poisoning. However, extensive differences were found by a SAR study for various substitutions on the non-oxime part of the reactivator molecule.

  11. Acetylcholinesterases of blood-feeding flies and ticks.

    Temeyer, Kevin B; Tuckow, Alexander P; Brake, Danett K; Li, Andrew Y; Pérez de León, Adalberto A

    2013-03-25

    Acetylcholinesterase (AChE) is the biochemical target of organophosphate (OP) and carbamate pesticides for invertebrates, vertebrate nerve agents, and AChE inhibitors used to reduce effects of Alzheimer's disease. Organophosphate pesticides (OPs) are widely used to control blood-feeding arthropods, including biting flies and ticks. However, resistance to OPs in pests affecting animal and human health has compromised control efficacy. OP resistance often results from mutations producing an OP-insensitive AChE. Our studies have demonstrated production of OP-insensitive AChEs in biting flies and ticks. Complementary DNA (cDNA) sequences encoding AChEs were obtained for the horn fly, stable fly, sand fly, and the southern cattle tick. The availability of cDNA sequences enables the identification of mutations, expression and characterization of recombinant proteins, gene silencing for functional studies, as well as in vitro screening of novel inhibitors. The southern cattle tick expresses at least three different genes encoding AChE in their synganglion, i.e. brain. Gene amplification for each of the three known cattle tick AChE genes and expression of multiple alleles for each gene may reduce fitness cost associated with OP-resistance. AChE hydrolyzes the neurotransmitter, acetylcholine, but may have additional roles in physiology and development. The three cattle tick AChEs possess significantly different biochemical properties, and are expressed in neural and non-neural tissues, which suggest separation of structure and function. The remarkable complexity of AChEs in ticks suggested by combining genomic data from Ixodes scapularis with our genetic and biochemical data from Rhipicephalus microplus is suggestive of previously unknown gene duplication and diversification. Comparative studies between invertebrate and vertebrate AChEs could enhance our understanding of structure-activity relationships. Research with ticks as a model system offers the opportunity to

  12. Variation of Musca domestica L. acetylcholinesterase in Danish housefly populations

    Kristensen, Michael; Huang, Jing; Qiao, Chuan-Ling;

    2006-01-01

    Anti-cholinesterase resistance is in many cases caused by modified acetylcholinesterase (MACE). A comparison was made of toxicological data and AChE activity gathered from 21 field populations and nine laboratory strains of houseflies, Musca domestica L., to elucidate the best way of generating d...

  13. Dual Binding Site and Selective Acetylcholinesterase Inhibitors Derived from Integrated Pharmacophore Models and Sequential Virtual Screening

    Shikhar Gupta

    2014-01-01

    Full Text Available In this study, we have employed in silico methodology combining double pharmacophore based screening, molecular docking, and ADME/T filtering to identify dual binding site acetylcholinesterase inhibitors that can preferentially inhibit acetylcholinesterase and simultaneously inhibit the butyrylcholinesterase also but in the lesser extent than acetylcholinesterase. 3D-pharmacophore models of AChE and BuChE enzyme inhibitors have been developed from xanthostigmine derivatives through HypoGen and validated using test set, Fischer’s randomization technique. The best acetylcholinesterase and butyrylcholinesterase inhibitors pharmacophore hypotheses Hypo1_A and Hypo1_B, with high correlation coefficient of 0.96 and 0.94, respectively, were used as 3D query for screening the Zinc database. The screened hits were then subjected to the ADME/T and molecular docking study to prioritise the compounds. Finally, 18 compounds were identified as potential leads against AChE enzyme, showing good predicted activities and promising ADME/T properties.

  14. Optimization of RNA interference (RNAi) targeting acetylcholinesterase in the Southern cattle tick (Rhipicephalus microplus)

    Acetylcholinesterase (AChE) is the primary target for organophosphate (OP) acaricides. OP resistant strains of the Southern cattle tick Rhipicephalus microplus have been identified and represent a major threat to the control of this important disease vector. R. microplus ticks possess at least three...

  15. Acetylcholinesterase inhibition as an indicator of organophosphate and carbamate poisoning in Kenyan agricultural workers.

    Ohayo-Mitoko, G.J.A.; Heederik, D.; Kromhout, H.; Omondi, B.E.O.; Boleij, J.S.M.

    1997-01-01

    Acetylcholinesterase inhibition was determined for 666 Kenyan agricultural workers; 390 (58.6%) mainly pesticide applicators exposed to organophosphate and carbamate pesticides and 276 (41.4%) unexposed controls from four rural agricultural areas during 1993 and 1994. Baseline levels were depressed

  16. Fenugreek hydrogel–agarose composite entrapped gold nanoparticles for acetylcholinesterase based biosensor for carbamates detection

    Kestwal, Rakesh Mohan; Bagal-Kestwal, Dipali; Chiang, Been-Huang, E-mail: bhchiang@ntu.edu.tw

    2015-07-30

    A biosensor was fabricated to detect pesticides in food samples. Acetylcholinesterase was immobilized in a novel fenugreek hydrogel–agarose matrix with gold nanoparticles. Transparent thin films with superior mechanical strength and stability were obtained with 2% fenugreek hydrogel and 2% agarose. Immobilization of acetylcholinesterase on the membrane resulted in high enzyme retention efficiency (92%) and a significantly prolonged shelf life of the enzyme (half-life, 55 days). Transmission electron microscopy revealed that, gold nanoparticles (10–20 nm in diameter) were uniformly dispersed in the fenugreek hydrogel–agarose–acetylcholinesterase membrane. This immobilized enzyme-gold nanoparticle dip-strip system detected various carbamates, including carbofuran, oxamyl, methomyl, and carbaryl, with limits of detection of 2, 21, 113, and 236 nM (S/N = 3), respectively. Furthermore, the fabricated biosensor exhibited good testing capabilities when used to detect carbamates added to various fruit and vegetable samples. - Highlights: • Acetylcholinesterase (AChE) dip-strip biosensor fabricated to detect carbamates. • AChE entrapped in fenugreek hydrogel–agarose matrix with gold nanoparticles (GNPs). • High enzyme retention efficiency (92%) and shelf life (half-life, 55 days). • Detection limits of carbofuran, oxamyl and methomyl: 2, 21 and 113 nM. • The biosensor had good testing capabilities to detect carbamates in food samples.

  17. Evaluating the antioxidant and acetylcholinesterase inhibitory activity of three Centaurea species

    H. Hajimehdipoor

    2014-01-01

    Full Text Available Factors such as oxidative stress and reduced acetylcholine level have been implicated in Alzheimer’s disease (AD pathology and recently there has been a trend towards natural product research to find potential sources of antioxidants and acetylcholinesterase inhibitors in the plants kingdom. Centaurea is a genus with about 500 species world wild, many of them have shown to possess biologic activity; Centaurea albonites, C. aucheri and C. pseudoscabiosa are three species which little investigation has been carried out about their biological properties. In the present study, the antioxidant and acetylcholinesterase inhibitory activity of the above mentioned species have been evaluated. The ability of the total extract and methanol fraction of the plants to scavenge free radicals has been assessed through DPPH radical scavenging assay, and the acetylcholinesterase inhibitory property has been evaluated by Ellman method. The total extract of all species exhibited moderate antioxidant activity whereas the extracts of C. pseudoscabiosa showed the strongest antioxidant property; its total extract also demonstrated the highest acetylcholinesterase inhibitory activity among the evaluated samples (19.2% inhibition. The results suggest the species as potential sources of natural antioxidants which could be focused in future studies of Alzheimer’s disease.

  18. Inhibition of acetylcholinesterase in guppies (Poecilia reticulata) by chlorpyrifos at sublethal concentrations: Methodological aspects

    van der Wel, H.; Welling, W.

    1989-04-01

    Acetylcholinesterase activity is a potential biochemical indicator of toxic stress in fish and a sensitive parameter for testing water for the presence of organophosphates. A number of methodological aspects regarding the determination of the in vivo effect of chlorpyrifos on acetylcholinesterase in guppies have been investigated. It was found that with acetylthiocholine as a substrate, the contribution of pseudocholinesterase to the total cholinesterase activity can be neglected. Protection of acetylcholinesterase of guppies exposed to chlorpyrifos from additional, artifactual in vitro enzyme inhibition during homogenization is necessary. Very low concentrations of acetone in the exposure medium, resulting from dilution of the stock solution of chlorpyrifos in acetone, can result in large decreases in the oxygen content of this medium. This may affect the uptake rate of the toxic compound and, thereby, cholinesterase inhibition. Very low, sublethal concentrations of chlorpyrifos result in high inhibition levels of acetylcholinesterase (80-90%) in guppies within 2 weeks of continuous exposure. Recovery of the enzyme activity occurs after the exposed animals are kept in clean medium for 4 days, but the rate of recovery is considerably lower than the rate of inhibition.

  19. Specification of the structure of oximes able to reactivate tabun-inhibited acetylcholinesterase.

    Cabal, Jirí; Kuca, K; Kassa, J

    2004-08-01

    The efficacy of various oximes to reactivate acetylcholinesterase phosphorylated by tabun (O-ethyl-N,N-dimethyl phosphoramidocyanidate) was tested by in vitro and in vivo methods. The oximes commonly used for the treatment of acute poisonings with highly toxic organophosphates appeared to be almost ineffective (HI-6, pralidoxime, methoxime) or just slightly effective (obidoxime) against tabun. On the other hand, trimedoxime seemed to be a significantly more efficacious reactivator than the others in the case of tabun poisonings. In vitro, the concentration of trimedoxime corresponding to 1.0 mmol/l was able to reach 50% reactivation of tabun-inhibited brain acetylcholinesterase. Higher reactivating potency of trimedoxime in comparison with the other commonly used oximes was demonstrated by in vivo method, too. In addition, other structural analogues of trimedoxime were found to be efficacious in counteracting tabun-induced acetylcholinesterase inhibition although not as efficacious as trimedoxime itself. Some effective acetylcholinesterase reactivators were characterised by dissociation constant of enzyme-reactivator complex as well as enzyme-inhibitor-reactivator complex and by rate constant of reactivation.

  20. Using NMR Spectroscopy to Investigate the Solution Behavior of Nerve Agents and Their Binding to Acetylcholinesterase

    2016-01-01

    USING NMR SPECTROSCOPY TO INVESTIGATE THE SOLUTION BEHAVIOR OF NERVE AGENTS AND THEIR BINDING TO...Solution Behavior of Nerve Agents and Their Binding to Acetylcholinesterase 5a. CONTRACT NUMBER CB3889 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...dynamics (MD) Nerve agent Nuclear magnetic relaxation Nuclear Overhauser effect (NOE) Solution behavior 16

  1. Screening of acetylcholinesterase inhibitors in snake venom by electrospray mass spectrometry

    Liesener, André; Perchuc, Anna-Maria; Schöni, Reto; Schebb, Nils Helge; Wilmer, Marianne; Karst, Uwe

    2007-01-01

    An electrospray ionization/mass spectrometry (ESI/MS)-based assay for the determination of acetylcholinesterase (AChE)-inhibiting activity in snake venom was developed. It allows the direct monitoring of the natural AChE substrate acetylcholine (AC) and the respective product choline. The assay sche

  2. Acetylcholinesterase of the sand fly, Phlebotomus papatasi (Scopoli): construction, expression and biochemical properties of the G119S orthologous mutant

    Phlebotomus papatasi vectors zoonotic cutaneous leishmaniasis, widespread in intertropical and temperate regions of the world. Previous cloning, expression, and biochemical characterization of recombinant P. papatasi acetylcholinesterase 1 (PpAChE1) revealed 85% amino acid sequence identity to mosq...

  3. Molecular dynamics of the interaction of pralidoxime and deazapralidoxime with acetylcholinesterase inhibited by the neurotoxic agent tabun

    Gonçalves,Arlan da S.; França,Tanos C. C.; Wilter,Alan; Figueroa-Villar,José D.

    2006-01-01

    Efficient acetylcholinesterase reactivators are fundamental for the development of antidotes against poisoning by neurotoxic pesticides and chemical warfare agents. However, the mechanism of the reactivation reaction and the structural characteristics of the known reactivators are poorly understood. In order to study the dynamic behavior and the effect of the antidote net charge in the reactivation of this enzyme, we carried out a molecular dynamics study of human acetylcholinesterase inhibit...

  4. Acetylcholinesterase activity in the brain of dystonia musculorum (Dst(dt-J)) mutant mice.

    Clément, C; Lalonde, R; Strazielle, C

    2012-01-01

    The dystonia musculorum (Dst(dt-J)) mutant mouse suffers from severe motor coordination deficits, characterized, among various symptoms, by a spastic ataxia and dystonic movements, indicating central defects in motor structures in addition to dystrophy of peripheral sensory tracts and partial degeneration of spinocerebellar tracts. Neurochemical alterations, notably in dopaminergic and noradrenergic systems, were previously observed in basal ganglia and cerebellum. A quantitative histochemical cartography of brain acetylcholinesterase activity in Dst(dt-J) mutants, in comparison with controls, revealed increases in the neostriatum, the habenula-interpeduncular pathway, the cholinergic pedunculopontine nucleus and its target structures, the thalamus, major regions of the basal ganglia, such as substantia nigra, ventral tegmental area, globus pallidum, and subthalamic nucleus, as well as in associated extrapyramidal regions, such as red nucleus, brainstem reticular formation, and superior colliculus. These acetylcholinesterase changes may play a role in motor deficits, particularly the dystonic symptomatology observed in the mutation.

  5. Alkaloid profiles and acetylcholinesterase inhibitory activities of Fumaria species from Bulgaria.

    Vrancheva, Radka Z; Ivanov, Ivan G; Aneva, Ina Y; Dincheva, Ivayla N; Badjakov, Ilian K; Pavlov, Atanas I

    2016-01-01

    GC-MS analysis of alkaloid profiles of five Fumaria species, naturally grown in Bulgaria (F. officinalis, F. thuretii, F. kralikii, F. rostellata and F. schrammii) and analysis of acetylcholinesterase inhibitory activity of alkaloid extracts were performed. Fourteen isoquinoline alkaloids were identified, with the principle ones being protopine, cryptopine, sinactine, parfumine, fumariline, fumarophycine, and fumaritine. Protopine contents, defined by HPLC analysis varied between 210.6 ± 8.8 μg/g DW (F. schrammii) and 334.5 ± 7.1 μg/g DW. (F. rostellata). While all of the investigated alkaloid extracts significantly inhibited acetylcholinesterase activity, the F. kralikii demonstrated the highest level of inhibition (IC(50) 0.13 ± 0.01 mg extract/mL).

  6. Flavoring extracts of Hemidesmus indicus roots and Vanilla planifolia pods exhibit in vitro acetylcholinesterase inhibitory activities.

    Kundu, Anish; Mitra, Adinpunya

    2013-09-01

    Acetylcholinesterase inhibitors (AChEIs) are important for treatment of Alzheimer's disease and other neurological disorders. Search for potent and safe AChEIs from plant sources still continues. In the present work, we explored fragrant plant extracts that are traditionally used in flavoring foods, namely, Hemidesmus indicus and Vanilla planifolia, as possible sources for AChEI. Root and pod extracts of H. indicus and V. planifolia, respectively, produce fragrant phenolic compounds, 2-hydroxy-4-methoxybenzaldehyde (MBALD) and 4-hydroxy-3-methoxybenzaldehyde (vanillin). These methoxybenzaldehydes were shown to have inhibitory potential against acetylcholinesterase (AChE). Vanillin (IC50 = 0.037 mM) was detected as more efficient inhibitor than MBALD (IC50 = 0.047 mM). This finding was supported by kinetic analysis. Thus, plant-based food flavoring agents showed capacity in curing Alzheimer's disease and other neurological dysfunctions.

  7. A sensitive biosensor for the fluorescence detection of the acetylcholinesterase reaction system based on carbon dots.

    Ren, Xiangling; Wei, Jianfei; Ren, Jun; Qiang, Li; Tang, Fangqiong; Meng, Xianwei

    2015-01-01

    The carbon dots (C-dots) with high fluorescence quantum yield were prepared using hydrothermal method. C-dots have been adopted as probes for the fluorescence turn-off detection of H2O2 based on the special sensibility for the hydroxyl radical. And then the biosensors for the detection of substrate and enzymes activities were established in the acetylcholinesterase reaction system, which were related to the production of H2O2. Specifically, the proposed fluorescent biosensor was successfully applied to detect the concentration of choline (in the range from 0.025 to 50 μM) and acetylcholine (in the range from 0.050 to 50 μM), and the activity of choline oxidase (in the range from 1 to 75 U/L) and acetylcholinesterase (1 to 80 U/L). These results showed a sensitive, universal, nontoxic and eco-friendly detecting technique has been developed.

  8. Synthesis and acetylcholinesterase inhibitory activity of polyhydroxylated sulfated steroids: structure/activity studies.

    Richmond, Victoria; Murray, Ana P; Maier, Marta S

    2013-11-01

    Disulfated and trisulfated steroids have been synthesized from cholesterol and their acetylcholinesterase inhibitory activity has been evaluated. In our studies we have found that the activity was not only dependent on the location of the sulfate groups but on their configurations. 2β,3α,6α-trihydroxy-5α-cholestan-6-one trisulfate (18) was the most active steroid with an IC50 value of 15.48 μM comparable to that of 2β,3α-dihydroxy-5α-cholestan-6-one disulfate (1). Both compounds were found to be less active than the reference compound eserine. The butyrylcholinesterase activity of 1 and 18 was one magnitude lower than that against acetylcholinesterase revealing a selective inhibitor profile.

  9. Chemical Constituents of Jacaranda oxyphylla and their Acetylcholinesterase Inhibitory and Antimicrobial Activities

    Vinicius Viana Pereira

    2016-05-01

    Full Text Available This study evaluated chemical composition of Jacaranda oxyphylla, acetylcholinesterase inhibitory and antimicrobial activities of the isolated compounds. Phytochemical investigation of leaves extract yielded three classes of substances: fatty compounds, sterols and triterpenes. Butyl hexadecanoate (1, fatty alcohol (2, 2-(4-hydroxyphenylethyl triacontanoate (3, β -sitosterol (4, sitosterol-3-O- β- D -glucoside (5, 6'-palmitoyl-sitosterol-3-O- β- D -glucoside (6, oleanolic acid (7, ursolic acid (8 and corosolic acid (9 were obtained from n-hexane, CHCl 3 and EtOH extracts of J. oxyphylla. It was found a pronounced acetylcholinesterase inhibitory activity for the fatty compounds 1-3 and sterols 5 and 6, with values between 60 to 77%. Substances 7-9 presented a high antibacterial action against Bacillus cereus and Salmonella typhimurium, with values of growth inhibition in the range of 84 to 90%.

  10. A Common Mechanism for Resistance to Oxime Reactivation of Acetylcholinesterase Inhibited by Organophosphorus Compounds

    2013-01-01

    Organophosphates and Carbamates, Butterworth & Heinemann, Oxford, 1992. pp. 555–577. [2] P. Taylor, Anticholinesterase agents, in: L.L. Brunton, J.S...agent poisoning by in vitro analysis, Toxicol. Appl. Pharmacol. 219 (2007) 226–234. [7] A. Ashani, Z. Radic, I. Tsigelny, D.C. Vellom, N.A. Pickering... organophosphate -inhibited fetal bovine serum acetylcholinesterase by monoquaternary and bisquaternary ligands, Mol. Pharmacol. 55 (1998) 718– 726. [19] Z. Kovarik

  11. Synthesis and anti-acetylcholinesterase activity of benzotriazinone-triazole systems

    SETAREH MOGHIMI; FERESHTEH GOLI-GARMROODI; HEDIEH PILALI; MOHAMMAD MAHDAVI; LOGHMAN FIROOZPOUR; HAMID NADRI; ALIREZA MORADI; ALI ASADIPOUR; ABBAS SHAFIEE; ALIREZA FOROUMADI

    2016-09-01

    An approach for the construction of benzotriazinone-triazole system is described. The synthesis is based on diazonium chemistry and subsequent intramolecular heteroatom-heteroatom bond formation. The introduction of triazole moiety occurred via click reaction catalyzed by nano-sized copper, supported on modified silica mesopore KIT-5 leading to the desired products in excellent yield. Also, in vitro acetylcholinesterase(AChE) inhibitory activities of the target compounds were screened by Ellman’s method.

  12. [Effect of acetylcholinesterase reactivator dosage on its effectiveness in the treatment of tabun poisoning in mice].

    Kassa, J

    2004-01-01

    The therapeutic efficacy of selected reactivators of acetylcholinesterase (obidoxime, oxime HI-6, trimedoxime) against acute tabun poisoning in dependence on their dose was examined in experiments on male mice. A comparison of the values of the medium lethal dose (LD50) of tabun in the intoxication influenced by an antidote therapy consisting of atropin and some of the oximes tested revealed that in all three oximes under study their dose markedly influenced their effect. The highest efficacy was always achieved when oximes were administered in the maximal therapeutic dose (20% of LD50). It follows from the comparison of the efficacy of equieffective doses of the oximes tested that in all doses the acute lethal effects of tabun are most effectively eliminated by trimedoxime, and on the other hand, obidoxime seems to be least effective, though in the smallest dose tested (2% of LD50) the differences between the therapeutic efficacy of the individual oximes are not statistically significant. Oxime HI-6 is significantly more effective than obidoxime (in a dose corresponding to 20% of LD50), but it is less effective than trimedoxime (in a dose corresponding to 5% LD50). The achieved results have shown that oxime HI-6, so effective against soman, another nerve agent, is not the most advantageous reactivator of acetylcholinesterase for the therapy of acute tabun poisonings, though its efficacy is partly eliminated by its possible higher dosing in human medicine due to its lower toxicity for mammals. The most suitable reactivator of acetylcholinesterase for the elimination of acute lethal toxic effects of tabun seems to be trimedoxime. Obidoxime, which is the most widely used reactivator of acetylcholinesterase in the therapy of poisonings by nerve agents at present, is, like in the case of soman poisonings, a relatively least suitable oxime ensuring the survival in lethal tabun poisonings.

  13. Development of acetylcholinesterase biosensors for neurotoxins detection in foods and the environment

    Roepcke, Clarisse Brüning Schmitt

    2011-01-01

    Acetylcholinesterase (AChE) is responsible for the hydrolysis of acetylcholine in the nervous system. It is inhibited by several substances, like organophosphate and carbamate insecticides, glycoalkaloids, nerve gas and anatoxin-a(s). There is a growing need to develop new technologies to reduce time spent with sample preparation, discriminate between positive and negative samples, and to reduce analysis costs. Over the last decades, AChE biosensors have emerged as an ultra sensitive and rapi...

  14. Synthesis and in vitro acetylcholinesterase and butyrylcholinesterase inhibitory potential of hydrazide based Schiff bases.

    Rahim, Fazal; Ullah, Hayat; Taha, Muhammad; Wadood, Abdul; Javed, Muhammad Tariq; Rehman, Wajid; Nawaz, Mohsan; Ashraf, Muhammad; Ali, Muhammad; Sajid, Muhammad; Ali, Farman; Khan, Muhammad Naseem; Khan, Khalid Mohammed

    2016-10-01

    To discover multifunctional agents for the treatment of Alzheimer's disease, a series of hydrazide based Schiff bases were designed and synthesized based on multitarget-directed strategy. We have synthesized twenty-eight analogs of hydrazide based Schiff bases, characterized by various spectroscopic techniques and evaluated in vitro for acetylcholinesterase and butyrylcholinesterase inhibition. All compounds showed varied degree of acetylcholinesterase and butyrylcholinesterase inhibition when compared with standard Eserine. Among the series, compounds 10, 3 and 24 having IC50 values 4.12±0.01, 8.12±0.01 and 8.41±0.06μM respectively showed potent acetylcholinesterase inhibition when compared with Eserine (IC50=0.85±0.0001μM). Three compounds 13, 24 and 3 having IC50 values 6.51±0.01, 9.22±0.07 and 37.82±0.14μM respectively showed potent butyrylcholinesterase inhibition by comparing with eserine (IC50=0.04±0.0001μM). The remaining compounds also exhibited moderate to weak inhibitory potential. Structure activity relationship has been established. Through molecular docking studies the binding interaction was confirmed.

  15. The effects of a food product containing lactic acid on the activity of acetylcholinesterase

    Andre-Michael Beer

    2012-06-01

    Full Text Available Objective: Patients reported that a food product containing lactic acid improved their memory and thought processes. The ingredients of the tested food product are compound substances and smooth muscle fibre, the appropriate medium in which to analyse their effects. Acetylcholinesterase inhibitors are used to treat memory loss and failing thought performance. The aim of this study was to compare the effects of the lactic acid food product with the effects of acetylcholinesterase inhibitors. Methods: In this in vitro study the effects of the food product containing lactic acid on smooth muscle fibres of guinea pig stomach were investigated. Results: The results show that the lactic acid food product contains substances that can inhibit the activity of both acetylcholinesterase and butyrylcholinesterase. This inhibitory effect was compared to the inhibitory effects of galantamine (Nivalin®, pyridostigmine bromide (Kalymin® and donepezil hydrochloride (Donepezil®, which are clinically used for the pharmacological treatment of dementia. We observed a 5% to 20% less potency factor difference with the lactic acid food product compared to that of the pharmaceutical drugs. Conclusions: This proves that the lactic acid food product can also have an impact on memory and thought performance and that these results should promote clinical trials to test efficacy. [J Exp Integr Med 2012; 2(3.000: 207-212

  16. Effect of Donepezil, Tacrine, Galantamine and Rivastigmine on Acetylcholinesterase Inhibition in Dugesia tigrina

    Cristiane Bezerra da Silva

    2016-01-01

    Full Text Available Dugesia tigrina is a non-parasitic platyhelminth, which has been recently utilized in pharmacological models, regarding the nervous system, as it presents a wide sensitivity to drugs. Our trials aimed to propose a model for an in vivo screening of substances with inhibitory activity of the enzyme acetylcholinesterase. Trials were performed with four drugs commercialized in Brazil: donepezil, tacrine, galantamine and rivastigmine, utilized in the control of Alzheimer’s disease, to inhibit the activity of acetylcholinesterase. We tested five concentrations of the drugs, with an exposure of 24 h, and the mortality and the inhibition of acetylcholinesterase planarian seizure-like activity (pSLA and planarian locomotor velocity (pLMV were measured. Galantamine showed high anticholinesterasic activity when compared to the other drugs, with a reduction of 0.05 μmol·min−1 and 63% of convulsant activity, presenting screw-like movement and hypokinesia, with pLMV of 65 crossed lines during 5 min. Our results showed for the first time the anticholinesterasic and convulsant effect, in addition to the decrease in locomotion induced by those drugs in a model of invertebrates. The experimental model proposed is simple and low cost and could be utilized in the screening of substances with anticholinesterasic action.

  17. The effect of engineered disulfide bonds on the stability of Drosophila melanogaster acetylcholinesterase

    Lamouroux Lucille

    2006-04-01

    Full Text Available Background Acetylcholinesterase is irreversibly inhibited by organophosphate and carbamate insecticides allowing its use in biosensors for detection of these insecticides. Drosophila acetylcholinesterase is the most sensitive enzyme known and has been improved by in vitro mutagenesis. However, its stability has to be improved for extensive utilization. Results To create a disulfide bond that could increase the stability of the Drosophila melanogaster acetylcholinesterase, we selected seven positions taking into account first the distance between Cβ of two residues, in which newly introduced cysteines will form the new disulfide bond and second the conservation of the residues in the cholinesterase family. Most disulfide bonds tested did not increase and even decreased the stability of the protein. However, one engineered disulfide bridge, I327C/D375C showed significant stability increase toward denaturation by temperature (170 fold at 50°C, urea, organic solvent and provided resistance to protease degradation. The new disulfide bridge links the N-terminal domain (first 356 aa to the C-terminal domain. The quantities produced by this mutant were the same as in wild-type flies. Conclusion Addition of a disulfide bridge may either stabilize or unstabilize proteins. One bond out of the 7 tested provided significant stabilisation.

  18. Influence of acetylcholinesterase immobilization on the photoluminescence properties of mesoporous silicon surface

    Saleem, Muhammad; Rafiq, Muhammad; Seo, Sung-Yum; Lee, Ki Hwan

    2014-07-01

    Acetylcholinesterase immobilized p-type porous silicon surface was prepared by covalent attachment. The immobilization procedure was based on support surface chemical oxidation, silanization, surface activation with cyanuric chloride and finally covalent attachment of free enzyme on the cyanuric chloride activated porous silicon surface. Different pore diameter of porous silicon samples were prepared by electrochemical etching in HF based electrolyte solution and appropriate sample was selected suitable for enzyme immobilization with maximum trapping ability. The surface modification was studied through field emission scanning electron microscope, EDS, FT-IR analysis, and photoluminescence measurement by utilizing the fluctuation in the photoluminescence of virgin and enzyme immobilized porous silicon surface. Porous silicon showed strong photoluminescence with maximum emission at 643 nm and immobilization of acetylcholinesterase on porous silicon surface cause considerable increment on the photoluminescence of porous silicon material while acetylcholinesterase free counterpart did not exhibit any fluorescence in the range of 635-670 nm. The activities of the free and immobilized enzymes were evaluated by spectrophotometric method by using neostigmine methylsulfate as standard enzyme inhibitor. The immobilized enzyme exhibited considerable response toward neostigmine methylsulfate in a dose dependent manner comparable with that of its free counterpart alongside enhanced stability, easy separation from the reaction media and significant saving of enzyme. It was believed that immobilized enzyme can be exploited in organic and biomolecule synthesis possessing technical and economical prestige over free enzyme and prominence of easy separation from the reaction mixture.

  19. Influence of acetylcholinesterase immobilization on the photoluminescence properties of mesoporous silicon surface

    Saleem, Muhammad [Department of Chemistry, Kongju National University, Gongju, Chungnam 314-701 (Korea, Republic of); Rafiq, Muhammad; Seo, Sung-Yum [Department of Biology, Kongju National University, Gongju, Chungnam 314-701 (Korea, Republic of); Lee, Ki Hwan, E-mail: khlee@kongju.ac.kr [Department of Chemistry, Kongju National University, Gongju, Chungnam 314-701 (Korea, Republic of)

    2014-07-01

    Acetylcholinesterase immobilized p-type porous silicon surface was prepared by covalent attachment. The immobilization procedure was based on support surface chemical oxidation, silanization, surface activation with cyanuric chloride and finally covalent attachment of free enzyme on the cyanuric chloride activated porous silicon surface. Different pore diameter of porous silicon samples were prepared by electrochemical etching in HF based electrolyte solution and appropriate sample was selected suitable for enzyme immobilization with maximum trapping ability. The surface modification was studied through field emission scanning electron microscope, EDS, FT-IR analysis, and photoluminescence measurement by utilizing the fluctuation in the photoluminescence of virgin and enzyme immobilized porous silicon surface. Porous silicon showed strong photoluminescence with maximum emission at 643 nm and immobilization of acetylcholinesterase on porous silicon surface cause considerable increment on the photoluminescence of porous silicon material while acetylcholinesterase free counterpart did not exhibit any fluorescence in the range of 635–670 nm. The activities of the free and immobilized enzymes were evaluated by spectrophotometric method by using neostigmine methylsulfate as standard enzyme inhibitor. The immobilized enzyme exhibited considerable response toward neostigmine methylsulfate in a dose dependent manner comparable with that of its free counterpart alongside enhanced stability, easy separation from the reaction media and significant saving of enzyme. It was believed that immobilized enzyme can be exploited in organic and biomolecule synthesis possessing technical and economical prestige over free enzyme and prominence of easy separation from the reaction mixture.

  20. Hairy-root organ cultures for the production of human acetylcholinesterase

    Mor Tsafrir S

    2008-12-01

    Full Text Available Abstract Background Human cholinesterases can be used as a bioscavenger of organophosphate toxins used as pesticides and chemical warfare nerve agents. The practicality of this approach depends on the availability of the human enzymes, but because of inherent supply and regulatory constraints, a suitable production system is yet to be identified. Results As a promising alternative, we report the creation of "hairy root" organ cultures derived via Agrobacterium rhizogenes-mediated transformation from human acetylcholinesterase-expressing transgenic Nicotiana benthamiana plants. Acetylcholinesterase-expressing hairy root cultures had a slower growth rate, reached to the stationary phase faster and grew to lower maximal densities as compared to wild type control cultures. Acetylcholinesterase accumulated to levels of up to 3.3% of total soluble protein, ~3 fold higher than the expression level observed in the parental plant. The enzyme was purified to electrophoretic homogeneity. Enzymatic properties were nearly identical to those of the transgenic plant-derived enzyme as well as to those of mammalian cell culture derived enzyme. Pharmacokinetic properties of the hairy-root culture derived enzyme demonstrated a biphasic clearing profile. We demonstrate that master banking of plant material is possible by storage at 4°C for up to 5 months. Conclusion Our results support the feasibility of using plant organ cultures as a successful alternative to traditional transgenic plant and mammalian cell culture technologies.

  1. Acetylcholinesterase as a Biomarker in Environmental and Occupational Medicine: New Insights and Future Perspectives

    Maria Giulia Lionetto

    2013-01-01

    Full Text Available Acetylcholinesterase (AChE is a key enzyme in the nervous system. It terminates nerve impulses by catalysing the hydrolysis of neurotransmitter acetylcholine. As a specific molecular target of organophosphate and carbamate pesticides, acetylcholinesterase activity and its inhibition has been early recognized to be a human biological marker of pesticide poisoning. Measurement of AChE inhibition has been increasingly used in the last two decades as a biomarker of effect on nervous system following exposure to organophosphate and carbamate pesticides in occupational and environmental medicine. The success of this biomarker arises from the fact that it meets a number of characteristics necessary for the successful application of a biological response as biomarker in human biomonitoring: the response is easy to measure, it shows a dose-dependent behavior to pollutant exposure, it is sensitive, and it exhibits a link to health adverse effects. The aim of this work is to review and discuss the recent findings about acetylcholinesterase, including its sensitivity to other pollutants and the expression of different splice variants. These insights open new perspective for the future use of this biomarker in environmental and occupational human health monitoring.

  2. [Methods of pharmaceutical technology in preparation of pellets for detection of acetylcholinesterase inhibitors].

    Vetchý, David; Leštinová, Hana; Tušarová, Ivana

    2012-10-01

    A variety of methods and technical equipment are currently available for checking of air contaminants. Generally, all known and sophisticated methods are based on sampling of substances in the air using different collectors or their capture in a suitable medium. However, new detection methods particularly useful in outdoor conditions are still looking for. Detection systems must be transportable, fast acting, inexpensive, sensitive and selective, and their operation should not be complicated. Such an appropriate system for the detection of carbamates and highly toxic organophosphates is detection tubes with microcrystalline cellulose pellets containing immobilized acetylcholinesterase, by which analyzed air is sucked through. The detection is based on the colorimetric Ellman reaction. Experimental work deals with the use of pharmaceutical technology methods for preparation of new variants of pellets for the detection of acetylcholinesterase inhibitors with 20% and 50% content of inorganic fillers (aluminium oxide, kaolin, colloidal silica, nalsit) produced by extrusion / spheronization. Pellets were impregnated by acetylcholinesterase after evaluating quality parameters and were tested for their activity and inhibition with Ellmans reagent. Pellets without inorganic fillers, containing 50% of aluminium oxide and containing 20% of colloidal silica were evaluated as a suitable filling of detection tubes.

  3. Antioxidant and anti-acetylcholinesterase activities of extracts and secondary metabolites from Acacia cyanophylla

    Lotfi Ghribia; Hatem Ghouilaa; Amel Omrib; Malek Besbesb; Hichem Ben Janneta

    2014-01-01

    Objective: To investigate the antioxidant potential and anti-acetycholinesterase activity of compounds and extracts from Acacia cyanophylla (A. cyanophylla). Methods: Three polyphenolic compounds were isolated from ethyl acetate extract of A.cyanophylla flowers. They have been identified as isosalipurposide 1, quercetin 2 and naringenin 3. Their structures were elucidated by extensive spectroscopic methods including 1D and 2D NMR experiments as well as ES-MS. The prepared extracts and the isolated compounds 1-3 were tested for their antioxidant activity using 1’-1’-diphenylpicrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) scavenging assays and reducing power. They have been also investigated for inhibitory effect against acetylcholinesterase using the microplate assay.Results:(67.26 µg/mL). Isosalipurposide 1 showed a significant antiradical power against DPPH (81.9 µg/mL). All extracts showed a dose-dependent acetylcholinesterase inhibition. In terms of the IC50 value, the butanolic extract (16.03 µg/mL) was the most potent sample. Isosalipurposide 1 was found to be active against AChE with an IC50 value of 52.04 µg/mL. In the DPPH test, the EtOAc extract of flowers exhibited the highest antioxidant effect Conclusions: The results demonstrated the important antioxidant and anti-acetylcholinesterase activity of pure compounds and extracts from A. cyanophylla.

  4. Mutations in Acetylcholinesterase2 (ace2) increase the insensitivity of acetylcholinesterase to fosthiazate in the root-knot nematode Meloidogyne incognita.

    Huang, Wen-Kun; Wu, Qin-Song; Peng, Huan; Kong, Ling-An; Liu, Shi-Ming; Yin, Hua-Qun; Cui, Ru-Qiang; Zhan, Li-Ping; Cui, Jiang-Kuan; Peng, De-Liang

    2016-11-29

    The root-knot nematode Meloidogyne incognita causes severe damage to continuously cropping vegetables. The control of this nematode relies heavily on organophosphate nematicides in China. Here, we described resistance to the organophosphate nematicide fosthiazate in a greenhouse-collected resistant population (RP) and a laboratory susceptible population (SP) of M. incognita. Fosthiazate was 2.74-fold less toxic to nematodes from RP than that from SP. Quantitative real-time PCR revealed that the acetylcholinesterase2 (ace2) transcription level in the RP was significantly higher than that in the SP. Eighteen nonsynonymous amino acid differences in ace2 were observed between the cDNA fragments of the RP and SP. The acetylcholinesterase (AChE) protein activity in the RP was significantly reduced compared with that in the SP. After knocking down the ace2 gene, the ace2 transcription level was significantly decreased, but no negative impact on the infection of juveniles was observed. The 50% lethal concentration of the RNAi RP population decreased 40%, but the inhibition rate of fosthiazate against AChE activity was significantly increased in RP population. Thus, the increased fosthiazate insensitivity in the M. incognita resistant population was strongly associated with mutations in ace2. These results provide valuable insights into the resistance mechanism of root-knot nematode to organophosphate nematicides.

  5. Characterization of acetylcholinesterases, and their genes, from the hemipteran species Myzus persicae (Sulzer), Aphis gossypii (Glover), Bemisia tabaci (Gennadius) and Trialeurodes vaporariorum (Westwood).

    Javed, N; Viner, R; Williamson, M S; Field, L M; Devonshire, A L; Moores, G D

    2003-12-01

    Gene sequences encoding putative acetylcholinesterases have been reported for four hemipteran insect species. Although acetylcholinesterase insensitivity occurs in insecticide-resistant populations of each of these species, no mutations were detected in the gene sequences from the resistant insects. This, coupled with a series of experiments using novel reversible inhibitors to compare the biochemical characteristics of acetylcholinesterase from a range of insect species, showed that the cloned cDNA fragments are unlikely to encode the hemipteran synaptic acetylcholinesterases, and there is likely to be a second ace locus.

  6. 5,6-Dimethoxybenzofuran-3-one Derivatives: a Novel Series of Dual Acetylcholinesterase/Butyrylcholinesterase Inhibitors Bearing Benzyl Pyridinium Moiety

    Mohammad Abdollahi

    2013-02-01

    Full Text Available Several studies have been focused on design and synthesis of multi-target anti Alzheimer compounds. Utilizing of the dual Acetylcholinesterase/Butyrylcholinesterase inhibitors has gained more interest to treat the Alzheimer’s disease. As a part of a research program to find a novel drug for treating Alzheimer disease, we have previously reported 6-alkoxybenzofuranone derivatives as potent acetylcholinesterase inhibitors. In continuation of our work, we would like to report the synthesis of 5,6-dimethoxy benzofuranone derivatives bearing a benzyl pyridinium moiety as dual Acetylcholinesterase/Butyrylcholinesterase inhibitors.MethodsThe synthesis of target compounds was carried out using a conventional method. Bayer-Villiger oxidation of 3,4-dimethoxybenzaldehyde furnished 3,4-dimethoxyphenol. The reaction of 3,4-dimethoxyphenol with chloroacetonitrile followed by treatment with HCl solution and then ring closure yielded the 5,6-dimethoxy benzofuranone. Condensation of the later compound with pyridine-4-carboxaldehyde and subsequent reaction with different benzyl halides afforded target compounds. The biological activity was measured using standard Ellman’s method. Docking studies were performed to get better insight into interaction of compounds with receptor.ResultsThe in vitro anti acetylcholinesterase/butyrylcholinesterase activity of compounds revealed that, all of the target compounds have good inhibitory activity against both Acetylcholinesterase/Butyrylcholinesterase enzymes in which compound 5b (IC50 = 52 ± 6.38nM was the most active compound against acetylcholinesterase. The same binding mode and interactions were observed for the reference drug donepezil and compound 5b in docking study.ConclusionsIn this study, we presented a new series of benzofuranone-based derivatives having pyridinium moiety as potent dual acting Acetylcholinesterase/Butyrylcholinesterase inhibitors.

  7. Interleukin 6 modulates acetylcholinesterase activity of brain neurons; Effet de l`interleukine 6 sur l`activite de l`acetylcholinesterase des neurones centraux

    Clarencon, D.; Multon, E.; Galonnier, M.; Estrade, M.; Fournier, C.; Mathieu, J.; Mestries, J.C.; Testylier, G.; Fatome, M.

    1995-12-31

    Classically, radiation injuries results in a peripheral inflammatory process, and we have previously observed an early systemic interleukin 6 (IL-6) release following whole-body irradiation. Besides, we have demonstrated an early decrease of rat or primate brain acetylcholinesterase (AChE) activity a gamma exposure. The object of the present study is to find possible IL-6 systemic effects on the brain AChE activity. We show that, though intravenous (i.v.) or intra-cerebro-ventricular (ICV) injection of IL-6 can induce a drop in rat brain AChE activity, this cytokine induces only a slight decrease of the AChE release in cultured brain cells. (author). 3 refs.

  8. Effect of Calea serrata Less. n-hexane extract on acetylcholinesterase of larvae ticks and brain Wistar rats.

    Ribeiro, Vera Lucia Sardá; Vanzella, Cláudia; Moysés, Felipe dos Santos; Santos, Jaqueline Campiol Dos; Martins, João Ricardo Souza; von Poser, Gilsane Lino; Siqueira, Ionara Rodrigues

    2012-10-26

    Acetylcholinesterase (AChE), an enzyme that hydrolyses acetylcholine (ACh) at cholinergic synapses, is a target for pesticides and its inhibition by organophosphates leads to paralysis and death of arthropods. It has been demonstrated that the n-hexane extract of Calea serrata had acaricidal activity against larvae of Rhipicephalus (Boophilus) microplus and Rhipicephalus sanguineus. The aim of the present study was to understand the mechanism of the acaricidal action of C. serrata n-hexane extract are specifically to investigate the in vitro anticholinesterase activity on larvae of R. microplus and in brain structures of male Wistar rats. The n-hexane extract significantly inhibited in vitro acetylcholinesterase activity in R. microplus larvae and rat brain structures. The results confirm that inhibition of acetylcholinesterase is a possible mechanism of action of hexane extract at C. serrata.

  9. Acetylcholinesterase Inhibition and in Vitro and in Vivo Antioxidant Activities of Ganoderma lucidum Grown on Germinated Brown Rice

    Beong Ou Lim

    2013-06-01

    Full Text Available In this study, the acetylcholinesterase inhibition and in vitro and in vivo antioxidant activities of Ganoderma lucidum grown on germinated brown rice (GLBR were evaluated. In antioxidant assays in vitro, GLBR was found to have strong metal chelating activity, DPPH, ABTS, hydroxyl and superoxide radical scavenging activity. Cell-based antioxidant methods were used, including lipid peroxidation on brain homogenate and AAPH-induced erythrocyte haemolysis. In antioxidant assays in vivo, mice were administered with GLBR and this significantly enhanced the activities of antioxidant enzymes in the mice sera, livers and brains. The amount of total phenolic and flavonoid compounds were 43.14 mg GAE/g and 13.36 mg CE/g dry mass, respectively. GLBR also exhibited acetylcholinesterase inhibitory activity. In addition, HPLC analyses of GLBR extract revealed the presence of different phenolic compounds. These findings demonstrate the remarkable potential of GLBR extract as valuable source of antioxidants which exhibit interesting acetylcholinesterase inhibitory activity.

  10. Antioxidant and acetylcholinesterase inhibition properties of Amorpha fruticosa L. and Phytolacca americana L.

    Dimitrina Zh Zheleva-Dimitrova

    2013-01-01

    Full Text Available Background: Amorpha fruticosa L. and Phytolacca americana L. are native plants for North America, but invasive for Central Europe and the Mediterranean areas. Previous investigation reported DPPH radical scavenging activity of A. fruticosa seeds from Mississippi river basin and P. americana berries from Iran. The aim of the present study was to investigate methanol extracts from leaves and fruits of these invasive species growing in Bulgaria for radical scavenging and acetylcholinesterase inhibitory potential. Materials and Methods: Antioxidant activity was investigated using DPPH and ABTS free radicals; FRAP assay and inhibition of lipid peroxidation in linoleic acid system by FTC. Modified Ellman′s colorimetric method was carried out to quantify acetylcholinesterase inhibition potential. In addition, the quantities of total polyphenols, flavonoids, and hydroxycinnamic derivatives were determinated using Folin-Chiocalteu reagent, AlCl 3 , and Na 2 MoO 4 , respectively. Results: The highest concentrations of total polyphenols and flavonoids were found in A. fruticosa leaves (786.70±1.78 mg/g dry extract and 32.19±0.29 mg/g dry extract, respectively. A. fruticosa fruit was found to be the most enriched in total hydroxycinnamic derivatives (153.55±1.11 mg/g dry extract and demonstrated the highest antioxidant activity: DPPH, IC 50 9.83 μg/mL; ABTS, IC 50 2.90 μg/mL; FRAP , 642.95±3.95 μg TE/mg de, and acetylcholinesterase inhibitory activity, 48.86±0.55% (2 mg/mL. Conclusions: Phytolacca americana leaves and Amorpha fruticosa could be useful in therapy of free radical pathologies and neurodegenerative disorders.

  11. Brain antioxidant markers, cognitive performance and acetylcholinesterase activity of rats: efficiency of Sonchus asper

    Khan Rahmat

    2012-05-01

    Full Text Available Abstract Background Sonchus asper (SA is traditionally used as a folk medicine to treat mental disorders in Pakistan. The aim of this study was to investigate the effect of polyphenolic rich methanolic fraction of SA on cognitive performance, brain antioxidant activities and acetylcholinesterase activity in male rats. Methods 30 male Sprague–Dawley rats were equally divided into three groups in this study. Animals of group I (control received saline (vehicle, group II received SA (50 mg/kg body weight (b.w., and group III treated with SA (100 mg/kg b.w., orally in dimethyl sulphoxide (DMSO for 7 days. The effect of SA was checked on rat cognitive performance, brain antioxidatant and acetylcholinesterase activities. Evaluation of learning and memory was assessed by a step-through a passive avoidance test on day 6 after two habituation trials and an initial acquisition trial on day 5. Antioxidant potential was determined by measuring activities of superoxide dismutase (SOD, catalase (CAT, contents of thiobarbituric acid reactive substances (TBARS and reduced glutathione (GSH in whole-brain homogenates. Acetylcholinesterase (AChE activity was determined by the colorimetric method. Results Results showed that 100 mg/kg b.w., SA treated rats exhibited a significant improvement in learning and memory (step-through latency time. SA administration reduced lipid peroxidation products and elevated glutathione levels in the SA100-treated group. Furthermore, salt and detergent soluble AChE activity was significantly decreased in both SA-treated groups. Short-term orally supplementation of SA showed significant cognitive enhancement as well as elevated brain antioxidant enzymes and inhibited AChE activity. Conclusion These findings stress the critical impact of Sonchus asper bioactive components on brain function.

  12. THE EFFECTS OF OXIMES IN THE ASSAY OF ACETYLCHOLINESTERASE ACTIVITY IN LYSED ERYTHROCYTES IN VITRO

    M. Abdollahi.

    1997-06-01

    Full Text Available Organophosphorus compounds are known to inhibit the esteratic site of acetylcholinesterase by phosphorylation. The phosphorylated esteratic site of acetylcholinesterase undergoes hydrolytic regeneration at a slow or negligible rate. Nucleophilic agents such as hydroxytamine, hydroxamic acids, and oximes reactivate the enzyme more erapidfy than does spontaneous hydrolysis. The red cell cholinesterose activity was assayed using dithio bis-2-nitrobenzoic acid (DTNB commonly known as Ellman's reagent. The principle of this assay method is the rate of hydrolysis of acetylthiocholine (substrate by a red celt suspension. Thiocholine that is produced, forms a yellow complex, when EUman's reagent (DTNB is used in the assay. This was tested in vitro in lysed erythrocyte samples of 35 healthy persons who had no known exposure to cholinesterose inhibitors, after the observation of immediate increase in absorption of light at 440 nm. All of data were statistically analyzed using one-way ANOVA and student t-test. A value of p<0.01 was considered. Results of this study show an increased absorbance in 440 nm, for pretreated samples with pratidoxime. This was observed by doses of (0.1, 0.5, 1,2 mmol, p<0.01. It was also a good dose dependent increase in absorbance at 440 nm for pralidoxime, (r=0.940, p<0.01. Also there is a significant increase in absorbance at 440 nm for samples pretreated by obidoxime at doses of (0.1, 0.5, 1,2 mmol. There is also a good correlation between absorbance at 440 nm and variou doses of obidoxime (r=0.946 , p<0.01. It is concluded that oximes can hydrofyzes the substrate, which then would be a source of error in determination of acetylcholinesterase activity and must be token into account.

  13. Pharmacological evaluation of [{sup 11}c]donepezil as tracer for visualization of acetylcholinesterase by PET

    Vos, F. de E-mail: filipx.devos@rug.ac.be; Santens, P.; Vermeirsch, H.; Dewolf, I.; Dumont, F.; Slegers, G.; Dierckx, R.A.; Reuck, J. de

    2000-11-01

    Donepezil is a highly potent and selective reversible acetylcholinesterase inhibitor. [{sup 11}C]Donepezil is prepared by methylation with [{sup 11}C]CH{sub 3}I of the corresponding 6'-O-desmethylprecursor. Tissue distribution in mice revealed a high uptake in brain and rapid clearance from the blood. Metabolization studies in mice indicated the formation of one {sup 11}C-labeled polar metabolite that didn't penetrate the blood-brain barrier. Regional brain distribution in rabbits didn't reflect the measured achetylcholinesterase distribution in rabbit brain.

  14. Progress in mechanisms of acetylcholinesterase inhibitors and memantine for the treatment of Alzheimer's disease

    Shao-Min Li

    2015-01-01

    Full Text Available Alzheimer's disease (AD is the most common causes of dementia in the elderly. Currently, only two classes of drugs, acetylcholinesterase inhibitors (AChEIs and memantine are approved. AChEIs ameliorate cognitive and psychiatric symptoms in AD patients through activation of acetylcholine (ACh receptors by increased synaptic ACh levels and also have protective effects against glutamate neurotoxicity and inflammation, whereas memantine appears to mainly protect against excitotoxicity and neurodegeneration. Herein, we review the pharmacologic properties of the available AChEIs and memantine, and focus on recent progress in the mechanisms of AD in relation to acetylcholinergic and glutamatergic involvement.

  15. Detection of Carbofuran with Immobilized Acetylcholinesterase Based on Carbon Nanotubes-Chitosan Modified Electrode

    Shuping Zhang

    2013-01-01

    Full Text Available A sensitive and stable enzyme biosensor based on efficient immobilization of acetylcholinesterase (AChE to MWNTs-modified glassy carbon electrode (GCE with chitosan (CS by layer-by-layer (LBL technique for rapid determination of carbofuran has been devised. According to the inhibitory effect of carbamate pesticide on the enzymatic activity of AChE, we use carbofuran as a model pesticide. The inhibitory effect of carbofuran on the biosensor was proportional to concentration of carbofuran in the range from  g/L to  g/L with a detection limit of  g/L. This biosensor is a promising new method for pesticide analysis.

  16. Acetylcholinesterase Inhibition-Based Biosensor for Aluminum(III) Chronoamperometric Determination in Aqueous Media

    2014-01-01

    A novel amperometric biosensor for the determination of Al(III) based on the inhibition of the enzyme acetylcholinesterase has been developed. The immobilization of the enzyme was performed on screen-printed carbon electrodes modified with gold nanoparticles. The oxidation signal of acetylthiocholine iodide enzyme substrate was affected by the presence of Al(III) ions leading to a decrease in the amperometric current. The developed system has a detection limit of 2.1 ± 0.1 μM for Al(III). The...

  17. Molecular Modeling Studies of Piperidine Derivatives as New Acetylcholinesterase Inhibitors against Neurodegenerative Diseases

    Elaine F. F. da Cunha

    2013-01-01

    Full Text Available Neurodegenerative disorders are related to the progressive loss of structure or function and, eventually, death of neurons. These processes are responsible for diseases like Parkinson’s, Alzheimer’s, and Huntington’s, and the main molecular target for the drug design against these illnesses today is the enzyme acetylcholinesterase (AChE. Following this line, in the present work, we applied docking techniques to study some piperidine derivative inhibitors of AChE and further propose structures of six new AChE inhibitors as potential new drugs against neurodegenerative disorders. The best inhibitor proposed was submitted to additional molecular dynamics simulations steps.

  18. Analysis of Structure and Specific Functional Groups Involved in Acetylcholinesterase Catalysis and Inhibition

    1992-12-15

    et al., 1990). 2. SRpodoptera frugiperda (Sf9. Cells were typically grown in 250 mL of medium in a 500-mL spinner flask with slow stirring at 27"C in...reasonably good expression systems in Spodoptera for preparing large quantities of enzyme. The enzymes prepared from the baculovirus-Sjodo tera system were...4Standard Errors) for Wild-Type and Mutant Acetylcholinesterases Expressed in a Baculovirus- Spodoptera System’ enzyme 10’K, (M) Km tl/K. .. t 101K

  19. Expression of two types of acetylcholinesterase gene from the silkworm, Bombyx mori, in insect cells

    JIN-YAN SHANG; YA-MING SHAO; GUO-JUN LANG; GAN YUAN; ZHEN-HUA TANG; CHUAN-XI ZHANG

    2007-01-01

    Complementary DNAs encoding two types of acetylcholinesterase(AChE)were isolated from the silkworm, Bombyx mori. The type 1 (Bmace1) and type 2 (Bmace2) ORFs are 2052 and 1917 bp in length, respectively. Both the complete ORFs of the Bmaces and Cterminal truncated forms were recombined into the Bacmid baculovirus vector under the control of the polyhedrin promoter and expressed in Trichoplusia ni (Tn-5B 1-4) cells. The resulting products exhibited AChE activity and glycosylation of the expressed proteins. An inhibition assay indicated that the ace2-type enzyme was more sensitive than the acel-type enzyme to inhibition by eserine and paraoxon.

  20. Acetylcholinesterase Immobilized on Magnetic Beads for Pesticides Detection: Application to Olive Oil Analysis

    Ihya Ait-Ichou

    2012-06-01

    Full Text Available This work presents the development of bioassays and biosensors for the detection of insecticides widely used in the treatment of olive trees. The systems are based on the covalent immobilisation of acetylcholinesterase on magnetic microbeads using either colorimetry or amperometry as detection technique. The magnetic beads were immobilised on screen-printed electrodes or microtitration plates and tested using standard solutions and real samples. The developed devices showed good analytical performances with limits of detection much lower than the maximum residue limit tolerated by international regulations, as well as a good reproducibility and stability.

  1. Nanomaterials-Based Optical Techniques for the Detection of Acetylcholinesterase and Pesticides

    Ning Xia

    2014-12-01

    Full Text Available The large amount of pesticide residues in the environment is a threat to global health by inhibition of acetylcholinesterase (AChE. Biosensors for inhibition of AChE have been thus developed for the detection of pesticides. In line with the rapid development of nanotechnology, nanomaterials have attracted great attention and have been intensively studied in biological analysis due to their unique chemical, physical and size properties. The aim of this review is to provide insight into nanomaterial-based optical techniques for the determination of AChE and pesticides, including colorimetric and fluorescent assays and surface plasmon resonance.

  2. Chemical Constituents from Sonneratia ovata Backer and their in vitro Cytotoxicity and Acetylcholinesterase Inhibitory Activities

    Nguyen, Thi Hoai Thu; Huu Viet Thong, Phamb; Nguyen, KimTuyen Phamc

    2015-01-01

    -benzyl-β-d-glucopyranose (21) isolated from the leaves of Sonneratia ovata. Their chemical structures were established by spectroscopic data, as well as high resolution mass spectra and comparison with literature data. The in vitro acetylcholinesterase (AChE) inhibition and cytotoxic activities against HeLa (human epithelial...... carcinoma), NCI-H460 (human lung cancer), MCF-7 (human breast cancer) cancer cell lines and PHF (primary human fibroblast) cell were evaluated on some extracts and purified compounds at a concentration of 100 μg/mL. Compounds (5, 6, 23) exhibited cytotoxicity against the MCF-7 cell line with the IC50 values...

  3. GC-MS investigation and acetylcholinesterase inhibitory activity of Galanthus rizehensis.

    Sarikaya, Buket Bozkurt; Somer, Nehir Unver; Kaya, Gulen Irem; Onur, Mustafa Ali; Bastida, Jaume; Berkov, Strahil

    2013-01-01

    GC-MS (gas chromatography-mass spectrometry) analyses of alkaloids in the aerial parts and bulbs of Galanthus rizehensis Stern (Amaryllidaceae), collected during two different vegetation periods, was performed. Twenty three alkaloids were identified in four different alkaloid extracts. Acetylcholinesterase (AChE) inhibitory activities of the alkaloid extracts were tested. Both the highest alkaloid diversity and the most potent inhibitory activity (IC50 12.94 microg/ml) were obtained in extracts from the bulbs of G. rizehensis collected during the fruiting period.

  4. Structure-activity relationship for the reactivators of acetylcholinesterase inhibited by nerve agent VX.

    Kuca, Kamil; Musilek, Kamil; Jun, Daniel; Karasova, Jana; Soukup, Ondrej; Pejchal, Jaroslav; Hrabinova, Martina

    2013-08-01

    Nerve agents such as sarin, VX and tabun are organophosphorus compounds able to inhibit an enzyme acetylcholinesterase (AChE). AChE reactivators and anticholinergics are generally used as antidotes in the case of intoxication with these agents. None from the known AChE reactivators is able to reactivate AChE inhibited by all kinds of nerve agents. In this work, reactivation potency of seventeen structurally different AChE reactivators was tested in vitro and subsequently, relationship between their chemical structure and biological activity was outlined. VX was chosen as appropriate member of the nerve agent family.

  5. Monoquaternary pyridinium salts with modified side chain-synthesis and evaluation on model of tabun- and paraoxon-inhibited acetylcholinesterase.

    Musilek, Kamil; Kucera, Jiri; Jun, Daniel; Dohnal, Vlastimil; Opletalova, Veronika; Kuca, Kamil

    2008-09-01

    Acetylcholinesterase reactivators are crucial antidotes for the treatment of organophosphate intoxication. Eighteen monoquaternary reactivators of acetylcholinesterase with modified side chain were developed in an effort to extend the properties of pralidoxime. The known reactivators (pralidoxime, HI-6, obidoxime, trimedoxime, methoxime) and the prepared compounds were tested in vitro on a model of tabun- and paraoxon-inhibited AChE. Monoquaternary reactivators were not able to exceed the best known compounds for tabun poisoning, but some of them did show reactivation better or comparable with pralidoxime for paraoxon poisoning. However, extensive differences were found by a SAR study for various side chains on the non-oxime part of the reactivator molecule.

  6. Acetylcholinesterase-inhibiting activity of salicylanilide N-alkylcarbamates and their molecular docking.

    Imramovsky, Ales; Stepankova, Sarka; Vanco, Jan; Pauk, Karel; Monreal-Ferriz, Juana; Vinsova, Jarmila; Jampilek, Josef

    2012-08-24

    A series of twenty-five novel salicylanilide N-alkylcarbamates were investigated as potential acetylcholinesterase inhibitors. The compounds were tested for their ability to inhibit acetylcholinesterase (AChE) from electric eel (Electrophorus electricus L.). Experimental lipophilicity was determined, and the structure-activity relationships are discussed. The mode of binding in the active site of AChE was investigated by molecular docking. All the discussed compounds expressed significantly higher AChE inhibitory activity than rivastigmine and slightly lower than galanthamine. Disubstitution by chlorine in C'(₃,₄) of the aniline ring and the optimal length of hexyl-undecyl alkyl chains in the carbamate moiety provided the most active AChE inhibitors. Monochlorination in C'(₄) exhibited slightly more effective AChE inhibitors than in C'(₃). Generally it can be stated that compounds with higher lipophilicity showed higher inhibition, and the activity of the compounds is strongly dependent on the length of the N-alkyl chain.

  7. Phytochemicals content, antioxidant activity and acetylcholinesterase inhibition properties of indigenous Garcinia parvifolia fruit.

    Ali Hassan, Siti Hawa; Fry, Jeffrey R; Abu Bakar, Mohd Fadzelly

    2013-01-01

    Garcinia parvifolia belongs to the same family as mangosteen (Garcinia mangostana), which is known locally in Sabah as "asam kandis" or cherry mangosteen. The present study was conducted to determine the phytochemicals content (total phenolic, flavonoid, anthocyanin, and carotenoid content) and antioxidant and acetylcholinesterase inhibition activity of the flesh and peel of G. parvifolia. All samples were freeze-dried and extracted using 80% methanol and distilled water. For the 80% methanol extract, the flesh of G. parvifolia displayed higher phenolic and flavonoid contents than the peel, with values of 7.2 ± 0.3 mg gallic acid equivalent (GAE)/g and 5.9 ± 0.1 mg rutin equivalent (RU)/g, respectively. Anthocyanins were detected in the peel part of G. parvifolia but absent in the flesh. The peel of G. parvifolia displayed higher total carotenoid content as compared to the flesh part with the values of 17.0 ± 0.3 and 3.0 ± 0.0 mg β-carotene equivalents (BC)/100 g, respectively. The free-radical scavenging, ferric reducing, and acetylcholinesterase inhibition effect of the flesh were higher as compared to the peel in both extracts. These findings suggested that the edible part of G. parvifolia fruit has a potential as a natural source of antioxidant and anti-Alzheimer's agents.

  8. Kinetics of acetylcholinesterase inhibition by an aqueous extract of Cuminum cyminum seeds

    Suresh Kumar

    2014-03-01

    Full Text Available The cholinergic hypothesis of Alzheimer’s disease (AD has provided the rationale for the current pharmacotherapy of this disease. Acetylcholinesterase (AChE inhibitors are currently the only approved therapy for the symptomatic treatment of AD. The current drugs available in the market has shown various side effect which prompted scientist to search for new and potent AChE inhibitors which exerts minimal side effect in AD patient. In present study, an aqueous extract of Cumin cyminum was tested for in vitro acetylcholinesterase inhibitory activity based on Ellman’s method. C. cyminum showed maximum inhibition of 76.90±0.003% in an aqueous extract at 50μg/ml final concentration. Further studies were conducted to elucidate the mode of AChE inhibition by kinetic studies. Competitive inhibition was observed at lower concentrations (12.5μg/ml & 25μg/ml and mixed inhibition was observed at higher concentrations (50μg/ml & 100μg/ml.

  9. Acetylcholinesterase from Human Erythrocytes as a Surrogate Biomarker of Lead Induced Neurotoxicity

    Vivek Kumar Gupta

    2015-01-01

    Full Text Available Lead induced neurotoxicity in the people engaged in different occupations has received wide attention but very little studies have been carried out to monitor occupational neurotoxicity directly due to lead exposure using biochemical methods. In the present paper an endeavour has been made in order to assess the lead mediated neurotoxicity by in vitro assay of the activity of acetylcholinesterase (AChE from human erythrocytes in presence of different concentrations of lead. The results suggested that the activity of this enzyme was localized in membrane bound fraction and it was found to be highly stable up to 30 days when stored at −20°C in phosphate buffer (50 mM, pH 7.4 containing 0.2% Triton X-100. The erythrocyte’s AChE exhibited Km for acetylcholinesterase to be 0.1 mM. Lead caused sharp inhibition of the enzyme and its IC50 value was computed to be 1.34 mM. The inhibition of the enzyme by lead was found to be of uncompetitive type (Ki value, 3.6 mM which negatively influenced both the Vmax and the enzyme-substrate binding affinity. Taken together, these results indicate that AChE from human erythrocytes could be exploited as a surrogate biomarker of lead induced neurotoxicity particularly in the people occupationally exposed to lead.

  10. Oxidative stress biomarkers and acetylcholinesterase activity in human erythrocytes exposed to clomazone (in vitro).

    Santi, Adriana; Menezes, Charlene; Duarte, Marta Maria F; Leitemperger, Jossiele; Lópes, Thais; Loro, Vania L

    2011-09-01

    The aim of this study was to investigate the effect of clomazone herbicide on oxidative stress biomarkers and acetylcholinesterase activity in human erythrocytes in in vitro conditions. The activity of catalase (CAT), superoxide dismutase (SOD) and acetylcholinesterase (AChE), as well as the levels of thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH) were measured in human erythrocytes exposed (in vitro) to clomazone at varying concentrations in the range of 0, 100, 250 and 500 µg/L for 1 h at 37 °C.TBARS levels were significantly higher in erythrocytes incubated with clomazone at 100, 250 and 500 µg/L. However, erythrocyte CAT and AChE activities were decreased at all concentrations tested. SOD activity was increased only at 100 µg/L of clomazone. GSH levels did not change with clomazone exposure. These results clearly showed clomazone to induce oxidative stress and AChE inhibition in human erythrocytes (in vitro). We, thus, suggest a possible role of ROS on toxicity mechanism induced by clomazone in humans.

  11. Phytochemicals Content, Antioxidant Activity and Acetylcholinesterase Inhibition Properties of Indigenous Garcinia parvifolia Fruit

    Siti Hawa Ali Hassan

    2013-01-01

    Full Text Available Garcinia parvifolia belongs to the same family as mangosteen (Garcinia mangostana, which is known locally in Sabah as “asam kandis” or cherry mangosteen. The present study was conducted to determine the phytochemicals content (total phenolic, flavonoid, anthocyanin, and carotenoid content and antioxidant and acetylcholinesterase inhibition activity of the flesh and peel of G. parvifolia. All samples were freeze-dried and extracted using 80% methanol and distilled water. For the 80% methanol extract, the flesh of G. parvifolia displayed higher phenolic and flavonoid contents than the peel, with values of 7.2±0.3 mg gallic acid equivalent (GAE/g and 5.9±0.1 mg rutin equivalent (RU/g, respectively. Anthocyanins were detected in the peel part of G. parvifolia but absent in the flesh. The peel of G. parvifolia displayed higher total carotenoid content as compared to the flesh part with the values of 17.0±0.3 and 3.0±0.0 mg β-carotene equivalents (BC/100 g, respectively. The free-radical scavenging, ferric reducing, and acetylcholinesterase inhibition effect of the flesh were higher as compared to the peel in both extracts. These findings suggested that the edible part of G. parvifolia fruit has a potential as a natural source of antioxidant and anti-Alzheimer’s agents.

  12. Virtual Screening of Acetylcholinesterase Inhibitors Using the Lipinski’s Rule of Five and ZINC Databank

    Pablo Andrei Nogara

    2015-01-01

    Full Text Available Alzheimer’s disease (AD is a progressive and neurodegenerative pathology that can affect people over 65 years of age. It causes several complications, such as behavioral changes, language deficits, depression, and memory impairments. One of the methods used to treat AD is the increase of acetylcholine (ACh in the brain by using acetylcholinesterase inhibitors (AChEIs. In this study, we used the ZINC databank and the Lipinski’s rule of five to perform a virtual screening and a molecular docking (using Auto Dock Vina 1.1.1 aiming to select possible compounds that have quaternary ammonium atom able to inhibit acetylcholinesterase (AChE activity. The molecules were obtained by screening and further in vitro assays were performed to analyze the most potent inhibitors through the IC50 value and also to describe the interaction models between inhibitors and enzyme by molecular docking. The results showed that compound D inhibited AChE activity from different vertebrate sources and butyrylcholinesterase (BChE from Equus ferus (EfBChE, with IC50 ranging from 1.69 ± 0.46 to 5.64 ± 2.47 µM. Compound D interacted with the peripheral anionic subsite in both enzymes, blocking substrate entrance to the active site. In contrast, compound C had higher specificity as inhibitor of EfBChE. In conclusion, the screening was effective in finding inhibitors of AChE and BuChE from different organisms.

  13. A reversed-phase compatible thin-layer chromatography autography for the detection of acetylcholinesterase inhibitors.

    Ramallo, I Ayelen; García, Paula; Furlan, Ricardo L E

    2015-11-01

    A dual readout autographic assay to detect acetylcholinesterase inhibitors present in complex matrices adsorbed on reversed-phase or normal-phase thin-layer chromatography plates is described. Enzyme gel entrapment with an amphiphilic copolymer was used for assay development. The effects of substrate and enzyme concentrations, pH, incubation time, and incubation temperature on the sensitivity and the detection limit of the assay were evaluated. Experimental design and response surface methodology were used to optimize conditions with a minimum number of experiments. The assay allowed the detection of 0.01% w/w of physostigmine in both a spiked Sonchus oleraceus L. extract chromatographed on normal phase and a spiked Pimenta racemosa (Mill.) J.W. Moore leaf essential oil chromatographed on reversed phase. Finally, the reversed-phase thin-layer chromatography assay was applied to reveal the presence of an inhibitor in the Cymbopogon citratus (DC.) Stapf essential oil. The developed assay is able to detect acetylcholinesterase inhibitors present in complex matrixes that were chromatographed in normal phase or reversed-phase thin-layer chromatography. The detection limit for physostigmine on both normal and reversed phase was of 1×10(-4) μg. The results can be read by a change in color and/or a change in fluorescence.

  14. Structural evidence that human acetylcholinesterase inhibited by tabun ages through O-dealkylation.

    Carletti, Eugénie; Colletier, Jacques-Philippe; Dupeux, Florine; Trovaslet, Marie; Masson, Patrick; Nachon, Florian

    2010-05-27

    Tabun is a warfare agent that inhibits human acetylcholinesterase (hAChE) by rapid phosphylation of the catalytic serine. A time-dependent reaction occurs on the tabun adduct, leading to an "aged" enzyme, resistant to oxime reactivators. The aging reaction may proceed via either dealkylation or deamidation, depending on the stereochemistry of the phosphoramidyl adduct. We solved the X-ray structure of aged tabun-hAChE complexed with fasciculin II, and we show that aging proceeds through O-dealkylation, in agreement with the aging mechanism that we determined for tabun-inhibited human butyrylcholinesterase and mouse acetylcholinesterase. Noteworthy, aging and binding of fasciculin II lead to an improved thermostability, resulting from additional stabilizing interactions between the two subdomains that face each other across the active site gorge. This first structure of hAChE inhibited by a nerve agent provides structural insight into the inhibition and aging mechanisms and a structural template for the design of molecules capable of reactivating aged hAChE.

  15. Acetylcholinesterase of the Sand Fly, Phlebotomus papatasi (Scopoli): Construction, Expression and Biochemical Properties of the G119S Orthologous Mutant

    2014-12-10

    permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public...acetylcholinesterase. Bull Entomol Res 2005, 95:371–380. 24. Hassan MM, Widaa SO, Osman OM, Numiary MSM, Ibrahim MA, Abushama HM: Insecticide resistance in the

  16. Dissociable effects of acetylcholinesterase inhibitors and phosphodiesterase type 5 inhibitors on object recognition memory: acquisition versus consolidation

    Prickaerts, L.; Sik, A.; Staay, van der F.J.; Vente, de J.; Blokland, A.

    2005-01-01

    Rationale Phosphodiesterase enzyme type 5 (PDE5) inhibitors and acetylcholinesterase (AChE) inhibitors have cognition-enhancing properties. However, it is not known whether these drug classes affect the same memory processes. Objective We investigated the memory-enhancing effects of the PDE5 inhibit

  17. Design and synthesis of dual inhibitors of acetylcholinesterase and serotonin transporter targeting potential agents for Alzheimer's disease.

    Kogen, Hiroshi; Toda, Narihiro; Tago, Keiko; Marumoto, Shinji; Takami, Kazuko; Ori, Mayuko; Yamada, Naho; Koyama, Kazuo; Naruto, Shunji; Abe, Kazumi; Yamazaki, Reina; Hara, Takao; Aoyagi, Atsushi; Abe, Yasuyuki; Kaneko, Tsugio

    2002-10-03

    Highly efficient acetylcholinesterase (AChE) and serotonin transporter (SERT) dual inhibitors, (S)-4 and (R)-13 were designed and synthesized on the basis of the hypothetical model of AChE active site. Both compounds showed potent inhibitory activities against AChE and SERT. [structure: see text

  18. Identification and characterization of mutations in housefly (Musca domestica) acetylcholinesterase involved in insecticide resistance

    Walsh, Sinead B.; Dolden, Tracey A.; Moores, Graham D.

    2001-01-01

    Acetylcholinesterase (AChE) insensitive to organophosphate and carbamate insecticides has been identified as a major resistance mechanism in numerous arthropod species. However, the associated genetic changes have been reported in the AChE genes from only three insect species; their role in confe...... of the AChE protein from Torpedo californica and D. melanogaster....

  19. Effects of Green Tea Extract on Learning, Memory, Behavior and Acetylcholinesterase Activity in Young and Old Male Rats

    Kaur, Tranum; Pathak, C. M.; Pandhi, P.; Khanduja, K. L.

    2008-01-01

    Objective: To study the effects of green tea extract administration on age-related cognition in young and old male Wistar rats. Methods: Young and old rats were orally administered 0.5% green tea extract for a period of eight weeks and were evaluated by passive avoidance, elevated maze plus paradigm and changes in acetylcholinesterase activity.…

  20. The bispyridinium-dioxime HLö-7. A potent reactivator for acetylcholinesterase inhibited by the stereoisomers of tabun and soman

    Jong, L.P.A.de; Verhagen, M.A.A.; Langenberg, J.P.; Hagedorn, I.; Löffler, M.

    1989-01-01

    Purification of (+)-tabun was accomplished by treatment with electric eel acetylcholinesterase (AChE) in order to bind contaminating (-)-tabun, the more potent enantiomer with respect of AChE inhibition. Electric eel AChE inhibited with (-)-tabun and with purified (+)-tabun show similar properties i

  1. Development of a bifunctional sensor using haptenized acetylcholinesterase and application for the detection of cocaine and organophosphates

    Teller, Carsten; Halamek, Jan; Žeravík, Jiri; Stöcklein, Walter F.M.; Scheller, Frieder W.

    2008-01-01

    We developed a dual piezoelectric/amperometric sensor for the detection of two unrelated analytes in one experiment that uses propidium to anchor acetylcholinesterases (AChE) at the surface. This mass-sensitive sensor does not only allow the examination of the interaction between AChE and the modifi

  2. Acetylcholinesterase of Rhipicephalus (Boophilus) microplus and Phlebotomus papatasi: Gene Identification, Expression, and Biochemical Properties of Recombinant Proteins

    2013-01-01

    inspection of all imported cattle has prevented re-establish- ment of ‘‘cattle fever ticks’’ within the United States. The Texas Ani- mal Health...Q86GC8], and Aedes aegypti [GenBank: XP_001656977]. Recombinant acetylcholinesterase1 of P. papatasi expressed and biochemically characterized in

  3. Inhibitory and enzyme-kinetic investigation of chelerythrine and lupeol isolated from Zanthoxylum rhoifolium against krait snake venom acetylcholinesterase

    Ahmad, Mustaq, E-mail: mushtaq213@yahoo.com [University of Science and Technology, Bannu, (Pakistan). Department of Biotechnology; Weber, Andrea D.; Zanon, Graciane; Tavares, Luciana de C.; Ilha, Vinicius; Dalcol, Ionara I.; Morel, Ademir F., E-mail: ademirfariasm@gmail.com [Universidade Federal de Santa Maria, RS (Brazil). Dept. de Quimica

    2014-01-15

    The in vitro activity of chelerythrine and lupeol, two metabolites isolated from Zanthoxylum rhoifolium were studied against the venom of the snake Bungarus sindanus (Elapidae). The venom, which is highly toxic to humans, consists mainly by the enzyme acetylcholinesterase (AChE). Both compounds showed activity against the venom, and the alkaloid chelerythrine presented higher activity than did triterpene lupeol. (author)

  4. A radiotracer for In vivo studies of acetylcholinesterase: p-[{sup 18}F]fluorodonepezil

    Lee, S. Y.; Choi, Y. S.; Choi, Y.; Kim, S. E.; Lee, K. H.; Kim, B. T. [Samsung Medical Center, Seoul (Korea, Republic of); Lee, J. W. [Seoul National Univ., Seoul (Korea, Republic of)

    1999-05-01

    Alzheimer's disease (AD) is one of senile dementia caused by lack of acetylcholine in central nervous system, and in vivo studies of acetylcholinesterase (AChE) have been carried out using many radiolabeled AChE inhibitors (donepezil, tacrine, physostigmine, CP-126,998, etc). Donepezil, a FDA approved drug for AD is now in clinical use. Therefore, we synthesized and evaluated p-[{sup 18}F]fluorodonepezil in mice. Biodistribution studies demonstrated that p-[{sup 18}F]fluorodonepezil binds non-specifically in vivo and does not suffer from metabolism in mouse brain. This study suggests that radioligands with higher binding affinity may be required to visualize AChE in vivo and further studies are needed to develop better radiotracers.

  5. RanBPM is an acetylcholinesterase-interacting protein that translocates into the nucleus during apoptosis

    Xiaowen Gong; Weiyuan Ye; Haibo Zhou; Xiaohui Ren; Zhigang Li; Weiyin Zhou; Jun Wu; Yicheng Gong; Qi Ouyang; Xiaolin Zhao; Xuejun Zhang

    2009-01-01

    Acetylcholinesterase (ACHE) expression may be induced during apoptosis in various cell types. Here, we used the C-terminal of AChE to screen the human fetal brain library and found that it interacted with Ran-binding protein in the microtubule-organizing center (RanBPM). This interaction was further con-firmed by coimmunoprecipitation analysis. In HEK293T cells, RanBPM and AChE were hetero-geneously expressed in the cisplatin-untreated cyto-plasmic extracts and in the cisplatin-treated cytoplasmic or nuclear extracts. Our previous studies performed using morphologic methods have shown that AChE translocates from the cytoplasm to the nucleus during apoptosis. Taken together, these results suggest that RanBPM is an AChE-interacting protein that is translocated from the cytoplasm into the nucleus during apoptosis, similar to the trans-location observed in case of ACHE.

  6. Effect of chlorpyrifos and monocrotophos on locomotor behaviour and acetylcholinesterase activity of subterranean termites, Odontotermes obesus.

    Venkateswara Rao, J; Parvathi, K; Kavitha, P; Jakka, N M; Pallela, R

    2005-04-01

    The acute toxicity of chlorpyrifos and monocrotophos to subterranean termites, Odontotermes obesus (Rambur), has been studied by a paper contact method. The LC50 values for chlorpyrifos and monocrotophos were 0.046 and 0.148 microg cm(-2), respectively. Chlorpyrifos was 3.22-fold more toxic than monocrotophos. The effect of the pesticides on locomotor behaviour (velocity) and head acetylcholinesterase (AChE: EC 3.1.1.7) activity was estimated in LC50-exposed termites at intervals of 4, 8, 12, 16, 20 and 24 h. Chlorpyrifos- and monocrotophos-treated termites showed, respectively, 97 and 88% reduction in locomotor behaviour (velocity) after 24 h. At all time intervals the chlorpyrifos-treated termites exhibited more AChE inhibition and showed greater distorted behaviour than those exposed to monocrotophos. In vitro studies indicated that the I50 value (50% inhibition) for chlorpyrifos against AChE was 8.75 times that of monocrotophos.

  7. Acetylcholinesterase inhibition-based biosensor for aluminum(III) chronoamperometric determination in aqueous media.

    Barquero-Quirós, Miriam; Domínguez-Renedo, Olga; Alonso-Lomillo, Maria Asunción; Arcos-Martínez, María Julia

    2014-05-07

    A novel amperometric biosensor for the determination of Al(III) based on the inhibition of the enzyme acetylcholinesterase has been developed. The immobilization of the enzyme was performed on screen-printed carbon electrodes modified with gold nanoparticles. The oxidation signal of acetylthiocholine iodide enzyme substrate was affected by the presence of Al(III) ions leading to a decrease in the amperometric current. The developed system has a detection limit of 2.1 ± 0.1 μM for Al(III). The reproducibility of the method is 8.1% (n = 4). Main interferences include Mo(VI), W(VI) and Hg(II) ions. The developed method was successfully applied to the determination of Al(III) in spiked tap water . The analysis of a certified standard reference material was also carried out. Both results agree with the certified values considering the respective associated uncertainties.

  8. Structural and kinetic effects of mobile phone microwaves on acetylcholinesterase activity.

    Barteri, Mario; Pala, Alessandro; Rotella, Simona

    2005-03-01

    The present study provides evidence that "in vitro" simple exposure of an aqueous solution of electric eel acetylcholinesterase (EeAChE; EC 3.1.1.7.) to cellular phone emission alters its enzymatic activity. This paper demonstrates, by combining different experimental techniques, that radio frequency (RF) radiations irreversibly affect the structural and biochemical characteristics of an important CNS enzyme. These results were obtained by using a commercial cellular phone to reproduce the reality of the human exposition. This experimental procedure provided surprising effects collected practically without experimental errors because they were obtained comparing native and irradiated sample of the same enzyme solution. Although these results cannot be used to conclude whether exposure to RF during the use of cellular phone can lead to any hazardous health effect, they may be a significant first step towards further verification of these effects on other "ex vivo" or "in vivo" biological systems.

  9. Acetylcholinesterase Inhibition-Based Biosensor for Aluminum(III) Chronoamperometric Determination in Aqueous Media

    Barquero-Quirós, Miriam; Domínguez-Renedo, Olga; Alonso-Lomillo, Maria Asunción; Arcos-Martínez, María Julia

    2014-01-01

    A novel amperometric biosensor for the determination of Al(III) based on the inhibition of the enzyme acetylcholinesterase has been developed. The immobilization of the enzyme was performed on screen-printed carbon electrodes modified with gold nanoparticles. The oxidation signal of acetylthiocholine iodide enzyme substrate was affected by the presence of Al(III) ions leading to a decrease in the amperometric current. The developed system has a detection limit of 2.1 ± 0.1 μM for Al(III). The reproducibility of the method is 8.1% (n = 4). Main interferences include Mo(VI), W(VI) and Hg(II) ions. The developed method was successfully applied to the determination of Al(III) in spiked tap water. The analysis of a certified standard reference material was also carried out. Both results agree with the certified values considering the respective associated uncertainties. PMID:24811076

  10. Acetylcholinesterase Inhibition-Based Biosensor for Aluminum(III Chronoamperometric Determination in Aqueous Media

    Miriam Barquero-Quirós

    2014-05-01

    Full Text Available A novel amperometric biosensor for the determination of Al(III based on the inhibition of the enzyme acetylcholinesterase has been developed. The immobilization of the enzyme was performed on screen-printed carbon electrodes modified with gold nanoparticles. The oxidation signal of acetylthiocholine iodide enzyme substrate was affected by the presence of Al(III ions leading to a decrease in the amperometric current. The developed system has a detection limit of 2.1 ± 0.1 μM for Al(III. The reproducibility of the method is 8.1% (n = 4. Main interferences include Mo(VI, W(VI and Hg(II ions. The developed method was successfully applied to the determination of Al(III in spiked tap water . The analysis of a certified standard reference material was also carried out. Both results agree with the certified values considering the respective associated uncertainties.

  11. Inhibition effect of graphene oxide on the catalytic activity of acetylcholinesterase enzyme.

    Wang, Yong; Gu, Yao; Ni, Yongnian; Kokot, Serge

    2015-11-01

    Variations in the enzyme activity of acetylcholinesterase (AChE) in the presence of the nano-material, graphene oxide (GO), were investigated with the use of molecular spectroscopy UV-visible and fluorescence methods. From these studies, important kinetic parameters of the enzyme were extracted; these were the maximum reaction rate, Vm , and the Michaelis constant, Km . A comparison of these parameters indicated that GO inhibited the catalytic activity of the AChE because of the presence of the AChE-GO complex. The formation of this complex was confirmed with the use of fluorescence data, which was resolved with the use of the MCR-ALS chemometrics method. Furthermore, it was found that the resonance light-scattering (RLS) intensity of AChE changed in the presence of GO. On this basis, it was demonstrated that the relationship between AChE and GO was linear and such models were used for quantitative analyses of GO.

  12. Improving the knowledge on Piper betle: targeted metabolite analysis and effect on acetylcholinesterase.

    Valentão, Patrícia; Gonçalves, Rui F; Belo, Cristóvão; de Pinho, Paula Guedes; Andrade, Paula B; Ferreres, Federico

    2010-10-01

    Piper betle is a species growing in South East Asia, where its leaves are economically and medicinally important. To screen the highest possible number of volatile and semivolatile components, the leaves were subjected to headspace solid-phase microextraction, hydrodistillation and Soxhlet extraction, prior to analysis by GC/MS. Fifty compounds (identified by comparison with standard compounds or tentatively by National Institute of Standards and Technology database) were determined, 23 being described for the first time in this matrix. An aqueous extract was also analysed, in which only seven compounds were characterized. The organic acids' composition of this extract was determined by HPLC/UV and eight compounds are reported for the first time in P. betle. This extract also displayed acetylcholinesterase inhibitory capacity.

  13. Synthesis, Biological Evaluation and Molecular Modelling of 2′-Hydroxychalcones as Acetylcholinesterase Inhibitors

    Sri Devi Sukumaran

    2016-07-01

    Full Text Available A series of 2′-hydroxy- and 2′-hydroxy-4′,6′-dimethoxychalcones was synthesised and evaluated as inhibitors of human acetylcholinesterase (AChE. The majority of the compounds were found to show some activity, with the most active compounds having IC50 values of 40–85 µM. Higher activities were generally observed for compounds with methoxy substituents in the A ring and halogen substituents in the B ring. Kinetic studies on the most active compounds showed that they act as mixed-type inhibitors, in agreement with the results of molecular modelling studies, which suggested that they interact with residues in the peripheral anionic site and the gorge region of AChE.

  14. 3D-QSAR analysis of a new type of acetylcholinesterase inhibitors

    LIU; AiLin; GUANG; HongMei; ZHU; LiYa; DU; GuanHua; LEE; Simon; M.; Y.; WANG; YiTao

    2007-01-01

    Acetylcholinesterase (AChE) inhibitors are an important class of medicinal agents used for the treatment of Alzheimer's disease. A screening model of AChE inhibitor was used to evaluate the inhibition of a series of phenyl pentenone derivatives. The assay result showed that some compounds displayed higher inhibitory effects. In order to study the relationship between the bioactivities and the structures, 26 compounds with phenyl pentenone scaffold were analyzed. A 3D-QSAR model was constructed using the method of comparative molecular field analysis (CoMFA). The results of cross-validated R2cv=0.629, non-cross-validated R2=0.972, SE=0.331, and F=72.41 indicate that the 3D-model possesses an ability to predict the activities of new inhibitors, and the CoMFA model would be useful for the future design of new AChE inhibitors.

  15. Theoretical modeling study for the phosphonylation mechanisms of the catalytic triad of acetylcholinesterase by sarin.

    Wang, Jing; Gu, Jiande; Leszczynski, Jerzy

    2008-03-20

    Potential energy surfaces for the process of phosphonylation of the catalytic triad of acetylcholinesterase by sarin have been explored at the B3LYP/6-311G(d,p) level of theory through a computational study. It is concluded that the phosphonylation process involves a critical addition-elimination mechanism. The first nucleophilic addition process is the rate-determining step. The following elimination process of the fluoride ion comprises a composite reaction that includes several steps, and it occurs rapidly by comparison with the rate-determining step. The mobility characteristics of histidine play an important role in the reaction. A double proton-transfer mechanism is proposed for the catalytic triad during the phosphonylation process of sarin on AChE. The effect of aqueous solvation has been considered via the polarizable continuum model (PCM). One concludes that the energy barriers are generally lowered in solvent, compared to the gas-phase reactions.

  16. Dementia post-radiotherapy: improvement with acetylcholinesterase inhibitor A case report

    Antonio Eduardo Damin

    Full Text Available Abstract Cognitive decline associated with radiotherapy is a progressive complication that affects many patients submitted to this form of treatment. The lack of an effective treatment drives research for new treatment options to improve the quality of life of patients with this disorder. We report the case of a 64 year-old man who developed a severe dementia of the frontal subcortical type, which was associated with subcortical frontal lesions and appeared as a late complication of radiotherapy used to treat a pituitary tumor. After many pharmacological attempts to improve his cognitive and behavioral problems, the patient showed a significant improvement in the cognitive, functional and behavioral impairments after treatment with an acetylcholinesterase inhibitor. This report discusses hypotheses for the positive effect of this treatment.

  17. Evaluation of monoquaternary pyridinium oximes potency to reactivate tabun-inhibited human acetylcholinesterase.

    Odzak, Renata; Calić, Maja; Hrenar, Tomica; Primozic, Ines; Kovarik, Zrinka

    2007-04-20

    Monoquaternary N-benzyl-4-hydroxyiminomethylpyridinium bromide (Py-4-H) and its analogous with diverse substituents introduced into the phenyl ring (Py-4-CH(3), Py-4-Br, Py-4-Cl and Py-4-NO(2)) were synthesized in order to examine their potency as reactivators of tabun-inhibited human erythrocyte acetylcholinesterase (AChE; EC 3.1.1.7). Within 24h, the reactivation of tabun-inhibited AChE reached 80% with Py-4-CH(3), Py-4-Br and Py-4-Cl, 40% with Py-4-NO(2), and 30% with Py-4-H. The overall reactivation rate constants were up to 5.0min(-1)M(-1). All oximes inhibited human AChE reversibly, and the inhibition potency increased in the following order Py-4-Brtabun-phosphorylated human AChE.

  18. Graphene quantum dots for ultrasensitive detection of acetylcholinesterase and its inhibitors

    Li, Nan; Wang, Xuewan; Chen, Jie; Sun, Lei; Chen, Peng

    2015-09-01

    Graphene quantum dots (GQDs) are emerging zero-dimensional materials promising a wide spectrum of novel applications including development of optical sensors. Herein, a GQD-based fluorometric sensor is devised to detect acetylcholinesterase (AChE, a critical enzyme in central nervous system and neuromuscular junctions) with an ultralow detection limit (0.58 pM with S/N of 5.0), using a photoluminescence ‘turn-off’ mechanism. This simple ‘mix-and-detect’ platform can also be employed to sense a variety of compounds that can directly or indirectly inhibit the enzymatic activities of AChE, such as nerve gases, pesticides, and therapeutic drugs. As the proof-of-concept demonstrations, we show the sensitive detection of paraoxon (a pesticide), tacrine (a drug to treat Alzheimer’s disease), and dopamine (an important neurotransmitter).

  19. Conformation-activity studies on the interaction of berberine with acetylcholinesterase:Physical chemistry approach

    Jin Xiang; Changping Yu; Fang Yang; Ling Yang; Hong Ding

    2009-01-01

    Berberine has been reported as an acetylcholinesterase (AChE) inhibitor.With significantly low cytotoxicity,berberine will be developed for the clinical treatment of Alzheimer disease (AD) with higher efficacy and fewer side effects.This work investigated the structure change events of AChE that occur during the interaction with berberine by isothermal titration calorimetry (ITC),fluorescence titration,and circular dichroism (CD).The results show that the binding of berberine to AChE is mainly driven by a favorable entropy increase with a less weak affinity.Berberine causes a loss in enzymatic activity at a concentration much below the concentration which gradually exposed the tryptophan residues to a more hydrophilic environment and unfolded the protein,which indicates that the inhibition of AChE with berberine includes the main contributions of interaction and minor conformation change of the protein induced by the alkaloid.

  20. Efficient perturbation analysis of elastic network models - Application to acetylcholinesterase of T. californica

    Hamacher, K.

    2010-09-01

    Elastic network models in their different flavors have become useful models for the dynamics and functions of biomolecular systems such as proteins and their complexes. Perturbation to the interactions occur due to randomized and fixated changes (in molecular evolution) or designed modifications of the protein structures (in bioengineering). These perturbations are modifications in the topology and the strength of the interactions modeled by the elastic network models. We discuss how a naive approach to compute properties for a large number of perturbed structures and interactions by repeated diagonalization can be replaced with an identity found in linear algebra. We argue about the computational complexity and discuss the advantages of the protocol. We apply the proposed algorithm to the acetylcholinesterase, a well-known enzyme in neurobiology, and show how one can gain insight into the "breathing dynamics" of a structural funnel necessary for the function of the protein. The computational speed-up was a 60-fold increase in this example.

  1. Acetylcholinesterase, a senile plaque component, affects the fibrillogenesis of amyloid-beta-peptides.

    Alvarez, A; Bronfman, F; Pérez, C A; Vicente, M; Garrido, J; Inestrosa, N C

    1995-12-01

    Acetylcholinesterase (AChE) colocalizes with amyloid-beta peptide (A beta) deposits present in the brain of Alzheimer's patients. Recent studies showed that A beta 1-40 can adopt two different conformational states in solution (an amyloidogenic conformer, A beta ac, and a non-amyloidogenic conformer, A beta nac) which have distinct abilities to form amyloid fibrils. We report here that AChE binds A beta nac and accelerates amyloid formation by the same peptide. No such effect was observed with A beta ac, the amyloidogenic conformer, suggesting that AChE acts as a 'pathological chaperone' inducing a conformational transition from A beta nac into A beta ac in vitro.

  2. Molecular interactions of an alkaloid euchrestifoline as a new acetylcholinesterase inhibitor

    Fazal Ur Rehman

    2013-12-01

    Full Text Available Acetylcholinesterase (AChE inhibitors are well established therapeutic agents for clinical management of Alzheimer’s Diseases and other disorders associated with deficient cholinergic neurotransmission. In the current investigation, a new inhibitor has been reported for its significant AChE inhibitory. euchrestifoline was isolated from the extract of Murraya paniculata. Isolated compound showed significant enzyme inhibitory activity (IC50 value: 93.1 ± 0.0 μM. Molecular docking revealed structural insights behind its significant inhibitory activity. Various molecular interaction were found between euchrestifoline and Ache especially Ser122, Trp84 and Tyr121. This study indicated promising potential of euchrestifoline to be further developed and explored as potential lead compound.

  3. Acetylcholinesterase converts Met5-enkephalin-containing peptides to Met5-enkephalin.

    Dowton, M; Boelen, M

    1988-11-22

    Acetylcholinesterase (AChE; E.C. 3.1.1.7) was incubated with a number of enkephalin-containing neuropeptides found in the bovine adrenal medulla. Met5-enkephalin and Leu5-enkephalin were the most stable of the peptides studied, while precursors of Met5-enkephalin were converted to Met5-enkephalin. AChE is therefore capable of limited peptidase activity on Met5-enkephalin precursors. The enzyme hydrolysed the Met5-enkephalin precursor BAM-12P on the C-terminal side of the pair of basic amino acid residues, and cleaved basic amino acids from the carboxy-terminal of Met5-enkephalin-Arg6 and Met5-enkephalin-Arg6-Arg7. These results indicate that AChE, acting alone, is capable of the same pattern of enkephalin processing as that observed in the adrenal medulla.

  4. Acetylcholinesterase Inhibitory Activities of Flavonoids from the Leaves of Ginkgo biloba against Brown Planthopper

    Xiao Ding

    2013-01-01

    Full Text Available Ginkgo biloba is a traditional Chinese medicinal plant which has potent insecticidal activity against brown planthopper. The MeOH extract was tested in the acetylcholinesterase (AChE inhibitory assay with IC50 values of 252.1 μg/mL. Two ginkgolides and thirteen flavonoids were isolated from the leaves of Ginkgo biloba. Their structures were established on the basis of spectroscopic data interpretation. It revealed that the 13 isolated flavonoids were found to inhibit AChE with IC50 values ranging from 57.8 to 133.1 μg/mL in the inhibitory assay. AChE was inhibited dose dependently by all tested flavonoids, and compound 6 displayed the highest inhibitory effect against AChE with IC50 values of 57.8 μg/mL.

  5. Extracts from Traditional Chinese Medicinal Plants Inhibit Acetylcholinesterase, a Known Alzheimer’s Disease Target

    Dorothea Kaufmann

    2016-08-01

    Full Text Available Inhibition of acetylcholinesterase (AChE is a common treatment for early stages of the most general form of dementia, Alzheimer’s Disease (AD. In this study, methanol, dichloromethane and aqueous crude extracts from 80 Traditional Chinese Medical (TCM plants were tested for their in vitro anti-acetylcholinesterase activity based on Ellman’s colorimetric assay. All three extracts of Berberis bealei (formerly Mahonia bealei, Coptis chinensis and Phellodendron chinense, which contain numerous isoquinoline alkaloids, substantially inhibited AChE. The methanol and aqueous extracts of Coptis chinensis showed IC50 values of 0.031 µg/mL and 2.5 µg/mL, therefore having an up to 100-fold stronger AChE inhibitory activity than the already known AChE inhibitor galantamine (IC50 = 4.33 µg/mL. Combinations of individual alkaloids berberine, coptisine and palmatine resulted in a synergistic enhancement of ACh inhibition. Therefore, the mode of AChE inhibition of crude extracts of Coptis chinensis, Berberis bealei and Phellodendron chinense is probably due to of this synergism of isoquinoline alkaloids. All extracts were also tested for their cytotoxicity in COS7 cells and none of the most active extracts was cytotoxic at the concentrations which inhibit AChE. Based on these results it can be stated that some TCM plants inhibit AChE via synergistic interaction of their secondary metabolites. The possibility to isolate pure lead compounds from the crude extracts or to administer these as nutraceuticals or as cheap alternative to drugs in third world countries make TCM plants a versatile source of natural inhibitors of AChE.

  6. Isoflurane-induced spatial memory impairment in mice is prevented by the acetylcholinesterase inhibitor donepezil.

    Diansan Su

    Full Text Available Although many studies have shown that isoflurane exposure impairs spatial memory in aged animals, there are no clinical treatments available to prevent this memory deficit. The anticholinergic properties of volatile anesthetics are a biologically plausible cause of cognitive dysfunction in elderly subjects. We hypothesized that pretreatment with the acetylcholinesterase inhibitor donepezil, which has been approved by the Food and Drug Administration (FDA for the treatment of Alzheimer's disease, prevents isoflurane-induced spatial memory impairment in aged mice. In present study, eighteen-month-old mice were administered donepezil (5 mg/kg or an equal volume of saline by oral gavage with a feeding needle for four weeks. Then the mice were exposed to isoflurane (1.2% for six hours. Two weeks later, mice were subjected to the Morris water maze to examine the impairment of spatial memory after exposure to isoflurane. After the behavioral test, the mice were sacrificed, and the protein expression level of acetylcholinesterase (AChE, choline acetylase (ChAT and α7 nicotinic receptor (α7-nAChR were measured in the brain. Each group consisted of 12 mice. We found that isoflurane exposure for six hours impaired the spatial memory of the mice. Compared with the control group, isoflurane exposure dramatically decreased the protein level of ChAT, but not AChE or α7-nAChR. Donepezil prevented isoflurane-induced spatial memory impairments and increased ChAT levels, which were downregulated by isoflurane. In conclusions, pretreatment with the AChE inhibitor donepezil prevented isoflurane-induced spatial memory impairment in aged mice. The mechanism was associated with the upregulation of ChAT, which was decreased by isoflurane.

  7. Ace2, rather than ace1, is the major acetylcholinesterase in the silkworm, Bombyx moil

    Hui-Juan Chen; Zhen Liao; Xiao-Ming Hui; Guo-Qing Li; Fei Li; Zhao-Jun Han

    2009-01-01

    Two acetylcholinesterase (ace) genes have been reported in many insect species. In pests such as Helicoverpa assulta and Plutella xylostellas, acel gene encodes the predominant synaptic enzyme that is the main target of organophosphorus (OP) and carbamate pesticides. It has been reported that pesticide selection has an impact on the ace gene evolution. The domesticated silkworm, Bombyx mori, also has two ace genes. We studied ace gene expression and enzyme activities in silkworm as this has not faced pesticide selection over the past decades. The expression levels of two ace genes, Bm-acel and Bin-ace2, were estimated by quantitative real-time polymerase chain reaction. Bm-ace2 was expressed more highly than Bm-acel in all tested samples of different developmental stages or tissues, suggesting ace2, rather than ace 1, is the major type of acetylcholinesterase (ACHE) in Bombyx mori. This is inconsistent with the aforementioned lepidopterons agricultural pests, partly be due to the widespread use of pesticides that may induce high expression of the acel gene in these pests. Besides high expression in the head, Bm-acel also expresses highly in the silk glands and Bm-ace2 is abundant in the germline, implying both ace genes may have potential non-hydrolytic roles in development. Furthermore, we found that the m_RNA levels of two ace genes and their ratios (ace2/ace1) change day to day in the first and third instars. This challenges the conventional method of estimating enzymatic activity using crude extract as an enzyme solution, as it is a mixture of ACHE1 and ACHE2. An efficient and simple method for separating different ACHEs is necessary for reliable toxicological analyses.

  8. Distribution of Acetylcholinesterase Positive Neurons in the Oviduct of Laying Hen

    Jameel Ahmed Gandahi1,2,§, Noor Samad Gandahi2,§, Ping Yang1, Xun Guang Bian1, Muhammad Ghiasuddin Shah2, Moolchand Malhi1,2, Lin Li Zhang1, Qian Zhang1 and Qiusheng Chen1,*

    2013-04-01

    Full Text Available The acetylcholinesterase histochemistry is used to identify the cholinergic nerves in tissue sections. Little is known on localization of cholinergic nerves in the oviduct of laying hens. We have used this technique to localize and compare the acetylcholinergic neurons in different regions through the oviduct in laying hens. The cholinergic neurons were seen as single cells, pairs or three cells arranged together. The cytoplasm and the processes of positive neurons showed strong reaction, with an eccentric nucleus. Morphologically, the neurons were rounded and oval cells of unipolar, bipolar and multipolar shapes. Similar features were seen in the whole mounts. Varicose nerve fibers were present. Cholinergic neurons were commonly seen in the muscularis; the fibers ran along the muscularis, occasionally showed a bifurcation to enter the lamina propria, reaching the secondary and tertiary mucosal folds; the fibers also targeted the blood vessels in the intermuscular region. The regional distribution of cholinergic neurons was highest seen in the infundibulum; medium in the magnum, isthmus and uterus (shell gland, while vagina had significantly lower (P<0.05 number; i.e. 8.00±1.00, 5.33±0.33, 4.67±0.67; 5.67±0.33; and 3.67±0.33, respectively. The local comparison of cholinergic neurons in muscularis and lamina propria showed significantly higher (P<0.05 number in muscularis than lamina propria of the isthmus. It was concluded that acetylcholinesterase positive (cholinergic nerves may have a role in the regulation of the smooth muscle functions and blood supply in the oviduct of chicken.

  9. Surface modification of chitosan/PEO nanofibers by air dielectric barrier discharge plasma for acetylcholinesterase immobilization

    Dorraki, Naghme, E-mail: n.dorraki@web.sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Safa, Nasrin Navab [Laser and Plasma Research Institute, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Jahanfar, Mehdi [Protein Research Center, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Ghomi, Hamid [Laser and Plasma Research Institute, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Ranaei-Siadat, Seyed-Omid [Protein Research Center, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of)

    2015-09-15

    Highlights: • We used an economical and effective method for surface modification. • Chitosan/PEO nanofibrous membranes were modified by air-DBD plasma. • The most NH{sub 3}{sup +} group was generated on the 6 min plasma modified membrane. • We immobilized acetylcholinesterase on the plasma modified and unmodified membranes. • More enzyme activity was detected on the modified membrane by plasma. - Abstract: There are different methods to modify polymer surfaces for biological applications. In this work we have introduced air-dielectric barrier discharge (DBD) plasma at atmospheric pressure as an economical and safe method for modifying the surface of electrospun chitosan/PEO (90/10) nanofibers for acetylcholinesterase (AChE) immobilization. According to the contact angle measurement results, the nanofibers become highly hydrophilic when they are exposed to the DBD plasma for 6 min in compared to unmodified membrane. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) results reveal hydroxyl, C=O and NH{sub 3}{sup +} polar groups increment after 6 min plasma treatment. Contact angle measurements and ATR-FTIR results are confirmed by X-ray photoelectron spectroscopy (XPS). AChE at pH 7.4 carries a negative charge and after immobilization on the surface of plasma-treated nanofibrous membrane attracts the NH{sub 3}{sup +} group and more enzyme activity is detected on the plasma-modified nanofibers for 6 min in compared to unmodified nanofibers. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) are used for the surface topography and morphology characterization. The results have proved that air-DBD plasma is a suitable method for chitosan/PEO nanofibrous membrane modification as a biodegradable and functionalized substrate for enzyme immobilization.

  10. Exposure to acetylcholinesterase inhibitors alters the physiology and motor function of honeybees

    Sally M Williamson

    2013-02-01

    Full Text Available Cholinergic signalling is fundamental to neuro-muscular function in most organisms. Sub-lethal doses of neurotoxic pesticides that target cholinergic signalling can alter the behaviour of insects in subtle ways; their influence on non-target organisms may not be readily apparent in simple mortality studies. Beneficial arthropods such as honeybees perform sophisticated behavioural sequences during foraging that, if influenced by pesticides, could impair foraging success and reduce colony health. Here, we investigate the behavioural effects on honeybees of exposure to a selection of pesticides that target cholinergic signalling by inhibiting acetylcholinesterase (AChE. To examine how continued exposure to AChE inhibitors affected motor function, we fed adult foraging worker honeybees sub-lethal concentrations of these compounds in sucrose solution for 24 h. Using an assay for locomotion in bees, we scored walking, stopped, grooming, and upside down behaviour continuously for 15 min. At a 10nM concentration, all the AChE inhibitors caused similar effects on behaviour, notably increased grooming activity and changes in the frequency of bouts of behaviour such as head grooming. Coumaphos caused dose-dependent effects on locomotion as well as grooming behaviour, and a 1µM concentration of coumaphos induced symptoms of malaise such as abdomen grooming and defecation. Biochemical assays confirmed that the 4 compounds we assayed (coumaphos, aldicarb, chlorpyrifos, and donepezil or their metabolites acted as AChE inhibitors in bees. Furthermore, we show that transcript expression levels of two honeybee acetylcholinesterase inhibitors were selectively upregulated in the brain and in gut tissues in response to AChE inhibitor exposure. The results of our study imply that the effects of pesticides that rely on this mode of action have subtle yet profound effects on physiological effects on behaviour that could lead to reduced survival.

  11. Sub-acute Toxicity of Carbofuran on Acetylcholinesterase Activity in the Freshwater Catfish, Clarias batrachus

    2005-01-01

    The inhibition of acetylcholinesterase (ACHE) activity has been widely used as a biomarker in an animal exposed to the pesticides. However, the interaction of extensively used organocarbamate insecticide, carbofuran, with the nervous system of the aquatic organisms is not properly studied. AChE is a key enzyme which catalyses the hydrolysis of acetylcholine, a neurotransmitter at the neuromuscular junctions, and thus regulates the neurotransmission system. In the present study, we have evaluated the impact of sub-acute concentrations (0.01 and 0.02 mg/L i.e. 1/20th and 1/10th of LC50) of carbofuran on the activity of acetylcholinesterase,from different tissues of Clarias batrachus, a fresh water teleost, after 96 hr and 15 days exposure periods in vivo. The carbofuran significantly reduced the activity of AChE in different tissues of C. batrachus at both concentrations and periods of exposure. The greater inhibition of AChE activities were recorded in fish tissues at higher carbofuran concentration (0.02 mg/L) after longer (15days) treatment period. The inhibition of AChE activity in all fish tissues tested was dependent on pesticide concentration and the duration of treatment. AChE from the tissues of C. batrachus was found to be a true cholinesterase as it was completely inhibited by the small concentration (nM) of eserine as tested in vitro. It was found that carbofuran at very low concentration exerted significant inhibitory effect on AChE activity in fish tissues.

  12. Acetylcholinesterase inhibitory activity of lycopodane-type alkaloids from the Icelandic Lycopodium annotinum ssp. alpestre

    Halldórsdóttir, Elsa Steinunn; Jaroszewski, Jerzy W; Olafsdottir, Elin Soffia

    2010-01-01

    determined. Conformation of acrifoline was characterized using NOESY spectroscopy and molecular modelling. The isolated alkaloids were evaluated for their in vitro inhibitory activity against acetylcholinesterase and butyrylcholinesterase. Ligand docking studies based on mutated 3D structure of Torpedo...

  13. Acetylcholinesterase activities in marine snail (Cronia contracta) as a biomarker of neurotoxic contaminants along the Goa coast, West coast of India

    Gaitonde, D.; Sarkar, A.; Kaisary, S.; DeSilva, C.; Dias, C.F.M.; Rao, P.V.S.S.D.P.; Ray, D.; Nagarajan, R.; DeSousa, S.N.; Sarkar, S.; Patill, D.

    The measurement of acetylcholinesterase (AChE) activity is used worldwide as a biomarker of environmental contamination due to neurotoxic substances. In the present study the AChE activities was measured in marine snails (Cronia contracta) collected...

  14. Comparisons of Properties of Acetylcholinesterase from Two Field-Collected Populations of Oxya chinensis Thunberg (Orthoptera: Acrididae) and the Role of Acetylcholinesterase in the Susceptibility to Malathion

    WU Hai-hua; YANG Mei-ling; GUO Ya-ping; MA En-bo

    2005-01-01

    In this study, acetylcholinesterase (AChE) was extracted from two field-collected populations of Oxya chinensis (Xinxiang City, Henan Province and Changzhi City, Shanxi Province). AChE activities were decreased when concentrations of ATC increased, showing a characteristic phenomenon of substrate inhibition at high concentration in both populations. Such inhibition occurred at relatively low concentration for AChE from Xinxiang population but relatively high for AChE from Changzhi population. The kinetic study showed that there were no significant differences between the two populations in the Km values. The Km value in Changzhi population was only 1.09-fold higher than that in Xinxiang population. However,significant differences were observed between the two populations in Vmax values. The Vmaxvalue in Changzhi population was 1.32-fold higher than that in Xinxiang population. The inhibition study in vitro showed that the AChE from both populations exhibited similar rank order in sensitivity to inhibition by three OPs, as determined by comparison of their bimolecular rate constants (ki), from the most potent inhibition to the least was chlopyrifos-oxon > paraoxon >demeton-s-methyl for AChE from the two populations and that the ki values in Xinxiang population were lower than those in Changzhi population. The I50 values of AChE from Xinxiang population were 4.84-, 2.66-, and 1.92-fold less sensitive to inhibition by paraoxon, chlopyrifos-oxon, and demeton-s-methyl. These results were consistent with the results in bioassay. It is inferred that AChE insensitivity to OP insecticides plays an important role in the differences of insusceptibility of Oxya chinensis to malathion between the two populations.

  15. In vitro inhibitory potential of methanolic extract of Celosia argentea var. cristata on tyrosinase, acetylcholinesterase and butyrylcholinesterase enzymes

    Fatima Saqib

    2015-06-01

    Full Text Available In the current study, methanol extract of Celosia argentea var. cristata was tested for its inhibitory potential against tyrosinase, acetylcholinesterase and butyrylcholinesterase enzymes at the concentration of 0.5 mM by ELISA microtiter plate assays. A significant tyrosinase inhibitory activity (63.6%, acetylcholinesterase inhibitory activity (80.3% and butyrylcholinesterse inhibitory activity (68.24% was shown by crude methanolic extract of C. argentea var. cristata with respective IC50 values of 268.5 ± 0.2 µg/mL, 73.6 ± 0.1 µg/mL and 132.8 ± 0.9 µg/mL. The result of this study reveals the use of C. argentea var. cristata in skin hyperpigmentation, Parkinson’s disease and neurodegenerative disorders like Alzheimer’s disease and dementia.

  16. Acetylcholinesterase inhibition starting from extracts of Bauhinia variegata L., Bauhinia var. candida (Aiton Buch.-Ham., and Bauhinia ungulata L

    Kamilla Monteiro dos Santos

    2011-12-01

    Full Text Available INTRODUCTION: A treatment to the Alzheimer's disease consists inhibition of the acetylcholinesterase, which is responsible for the acetylcholine control in the synapses. METHODS: We have investigated the potential of inhibition of the acetylcholinesterase produced by hexane extracts of leaves, branches, and flowers from three Bauhinia specimens, which is based on the technique of thin layer chromatography and on identifying the organ of the plant that possesses larger concentration of inhibitors. RESULTS: Retention factor analysis shows values of 0.31aA, 0.31aA, and 0.46aB for flowers B. variegata, B. var. candida, and B. ungulata, respectively. CONCLUSIONS: The flower extract of B. ungulata is the most suitable for further studies on this inhibition.

  17. Acetylcholinesterase Inhibition by Biofumigant (Coumaran from Leaves of Lantana camara in Stored Grain and Household Insect Pests

    Yallappa Rajashekar

    2014-01-01

    Full Text Available Recent studies proved that the biofumigants could be an alternative to chemical fumigants against stored grain insect pests. For this reason, it is necessary to understand the mode of action of biofumigants. In the present study the prospectus of utilising Lantana camara as a potent fumigant insecticide is being discussed. Inhibition of acetylcholinesterase (AChE by Coumaran, an active ingredient extracted from the plant L. camara, was studied. The biofumigant was used as an enzyme inhibitor and acetylthiocholine iodide as a substrate along with Ellman’s reagent to carry out the reactions. The in vivo inhibition was observed in both dose dependent and time dependent in case of housefly, and the nervous tissue (ganglion and the whole insect homogenate of stored grain insect exposed to Coumaran. The possible mode of action of Coumaran as an acetylcholinesterase inhibitor is discussed.

  18. Histopathological alterations, biochemical responses and acetylcholinesterase levels in Clarias gariepinus as biomarkers of exposure to organophosphates pesticides.

    Doherty, V F; Ladipo, M K; Aneyo, I A; Adeola, A; Odulele, W Y

    2016-05-01

    Organophosphate pesticides, commonly used in large scale farming, have been found to be major contaminants in aquatic environment. Clarias gariepinus was exposed to acute and sublethal concentrations of phostoxin and DD Force to evaluate single and joint action toxicity of the organophosphates. Effects of phostoxin and DD force on antioxidant enzymes, fish organs and acetylcholinesterase levels in fingerlings and juveniles of C. gariepinus were also investigated. The lethal concentrations (96 h LC50) for phostoxin and DD Force were 0.631 and 1.759 mg/l, respectively. The results obtained from the bioassay showed that phostoxin was 2.8× more toxic than DD Force after exposure of C. gariepinus. Joint action toxicity evaluations of phostoxin and DD Force showed that the interaction between the chemicals was synergistic (RTU >1). The biochemical responses in the exposed fish differed significantly (P < 0.05) from the control fish. The result of acetylcholinesterase study revealed significant difference between acetylcholinesterase levels in the exposed fish and control, with reduction in the acetylcholineterase level in fish exposed to sublethal concentrations of phostoxin and DD Force. Haematological studies revealed an increase in WBC, RBC, PCV and platelets in the exposed fish. Histopathology of the gills showed shortened primary lamellae, loss of secondary lamellae and loss of ceratobrachial bones. In the acute toxicity studies, respiratory stress, erratic swimming and instant death of fish were observed in the exposed fish. This study reveals that changes in histopathology and acetylcholinesterase level are good biomarkers and can be successfully used to detect exposure to organophosphates pesticides in fish.

  19. In Vitro Antioxidant Properties, HIV-1 Reverse Transcriptase and Acetylcholinesterase Inhibitory Effects of Traditional Herbal Preparations Sold in South Africa

    2010-01-01

    The antioxidant potentials for fourteen multipurpose traditional herbal preparations sold in South Africa were determined using the DPPH radical scavenging, ferric reducing power and β-carotene-linoleic acid model system, the anti-HIV-1 reverse transcriptase (RT) enzyme inhibitory effects using an ELISA kit and acetylcholinesterase (AChE) enzyme inhibition using the microtitre plate assay. Nine of the herbal mixtures (Umzimba omubi, Umuthi wekukhwehlela ne zilonda, Mvusa ukunzi, Umpatisa inko...

  20. Flavonoids, Antioxidant Potential, and Acetylcholinesterase Inhibition Activity of the Extracts from the Gametophyte and Archegoniophore of Marchantia polymorpha L.

    Xin Wang

    2016-03-01

    Full Text Available Marchantia polymorpha L. is a representative bryophyte used as a traditional Chinese medicinal herb for scald and pneumonia. The phytochemicals in M. polymorpha L. are terpenoids and flavonoids, among which especially the flavonoids show significant human health benefits. Many researches on the gametophyte of M. polymorpha L. have been reported. However, as the reproductive organ of M. polymorpha L., the bioactivity and flavonoids profile of the archegoniophore have not been reported, so in this work the flavonoid profiles, antioxidant and acetylcholinesterase inhibition activities of the extracts from the archegoniophore and gametophyte of M. polymorpha L. were compared by radical scavenging assay methods (DPPH, ABTS, O2−, reducing power assay, acetylcholinesterase inhibition assay and LC-MS analysis. The results showed that the total flavonoids content in the archegoniophore was about 10-time higher than that of the gametophyte. Differences between the archegoniophore and gametophyte of M. polymorpha L. were observed by LC-MS analysis. The archegoniophore extracts showed stronger bio-activities than those of the gametophyte. The archegoniophore extract showed a significant acetylcholinesterase inhibition, while the gametophyte extract hardly inhibited it.

  1. Flavonoids, Antioxidant Potential, and Acetylcholinesterase Inhibition Activity of the Extracts from the Gametophyte and Archegoniophore of Marchantia polymorpha L.

    Wang, Xin; Cao, Jianguo; Wu, Yuhuan; Wang, Quanxi; Xiao, Jianbo

    2016-03-17

    Marchantia polymorpha L. is a representative bryophyte used as a traditional Chinese medicinal herb for scald and pneumonia. The phytochemicals in M. polymorpha L. are terpenoids and flavonoids, among which especially the flavonoids show significant human health benefits. Many researches on the gametophyte of M. polymorpha L. have been reported. However, as the reproductive organ of M. polymorpha L., the bioactivity and flavonoids profile of the archegoniophore have not been reported, so in this work the flavonoid profiles, antioxidant and acetylcholinesterase inhibition activities of the extracts from the archegoniophore and gametophyte of M. polymorpha L. were compared by radical scavenging assay methods (DPPH, ABTS, O(2-)), reducing power assay, acetylcholinesterase inhibition assay and LC-MS analysis. The results showed that the total flavonoids content in the archegoniophore was about 10-time higher than that of the gametophyte. Differences between the archegoniophore and gametophyte of M. polymorpha L. were observed by LC-MS analysis. The archegoniophore extracts showed stronger bio-activities than those of the gametophyte. The archegoniophore extract showed a significant acetylcholinesterase inhibition, while the gametophyte extract hardly inhibited it.

  2. Distributions of choline acetyltransferase and acetylcholinesterase activities in the retinal layers of the red-tailed hawk and road runner.

    White, L E; Ross, C D; Godfrey, D A

    1991-01-01

    The activities of choline acetyltransferase and acetylcholinesterase were assayed in submicrogram samples from layers of red-tailed hawk and road runner retina. Both enzyme activities were concentrated in and near the inner plexiform layer. Within the inner plexiform layers of both species, activities of each enzyme were concentrated in two bands, one in each half of this layer. Little choline acetyltransferase activity was found superficial to the middle third of the inner nuclear layer. The distributions of acetylcholinesterase activities corresponded well to those of choline acetyltransferase, except in the outer plexiform layer and the outer margin of the inner nuclear layer of the hawk. These distributions of enzyme activities indicate that populations of amacrine cells in the retinae of these species are cholinergic. In addition to these same cells and presumably cholinoceptive amacrine and ganglion cells, acetylcholinesterase activity in the hawk was associated with a population of horizontal cells that may be unrelated to synaptic cholinergic neurotransmission. Choline acetyltransferase activities associated with amacrine somata and processes were about four times greater in the hawk than in the road runner, suggesting important differences in the density and function of cholinergic elements between species. Possible synaptic relationships in the inner plexiform layer consistent with the interspecies differences in enzyme activities are considered.

  3. Distribution of intravenously administered acetylcholinesterase inhibitor and acetylcholinesterase activity in the adrenal gland: 11C-donepezil PET study in the normal rat.

    Tadashi Watabe

    Full Text Available PURPOSE: Acetylcholinesterase (AChE inhibitors have been used for patients with Alzheimer's disease. However, its pharmacokinetics in non-target organs other than the brain has not been clarified yet. The purpose of this study was to evaluate the relationship between the whole-body distribution of intravenously administered (11C-Donepezil (DNP and the AChE activity in the normal rat, with special focus on the adrenal glands. METHODS: The distribution of (11C-DNP was investigated by PET/CT in 6 normal male Wistar rats (8 weeks old, body weight  = 220 ± 8.9 g. A 30-min dynamic scan was started simultaneously with an intravenous bolus injection of (11C-DNP (45.0 ± 10.7 MBq. The whole-body distribution of the (11C-DNP PET was evaluated based on the Vt (total distribution volume by Logan-plot analysis. A fluorometric assay was performed to quantify the AChE activity in homogenized tissue solutions of the major organs. RESULTS: The PET analysis using Vt showed that the adrenal glands had the 2nd highest level of (11C-DNP in the body (following the liver (13.33 ± 1.08 and 19.43 ± 1.29 ml/cm(3, respectively, indicating that the distribution of (11C-DNP was the highest in the adrenal glands, except for that in the excretory organs. The AChE activity was the third highest in the adrenal glands (following the small intestine and the stomach (24.9 ± 1.6, 83.1 ± 3.0, and 38.5 ± 8.1 mU/mg, respectively, indicating high activity of AChE in the adrenal glands. CONCLUSIONS: We demonstrated the whole-body distribution of (11C-DNP by PET and the AChE activity in the major organs by fluorometric assay in the normal rat. High accumulation of (11C-DNP was observed in the adrenal glands, which suggested the risk of enhanced cholinergic synaptic transmission by the use of AChE inhibitors.

  4. Natural products inhibitors of the enzyme acetylcholinesterase Produtos naturais inibidores da enzima acetilcolinesterase

    José M. Barbosa Filho

    2006-06-01

    Full Text Available Alzheimer's disease (AD is a progressive, neurodegenerative pathology that primarily affects the elderly population, and is estimated to account for 50-60% of dementia cases in persons over 65 years of age. The main symptoms associated with AD involve cognitive dysfunction, primarily memory loss. Other features associated with the later stages of AD include language deficits, depression, behavioural problems including agitation, mood disturbances and psychosis. One of the most promising approaches for treating this disease is to enhance the acetylcholine level in the brain using acetylcholinesterase (AChE inhibitors. The present work reviews the literature on plants and plant-derived compounds inhibitors of enzyme acetylcholinesterase. The review refers to 309 plant extracts and 260 compounds isolated from plants, which are classified in appropriate chemical groups and model tested, and cites their activity. For this purpose 175 references were consulted.A Doença de Alzheimer (DA é uma patologia neurodegenerativa, progressiva, que afeta principalmente a população idosa, responsável por 50-60% dos casos de demência em pessoas com mais de 65 anos de idade. Os principais sintomas associado a DA envolve deficiência orgânica cognitiva, principalmente perda de memória. Outras características associadas com os estágios avançados de DA inclui déficit na linguagem, depressão, problemas de comportamento, inclusive agitação, alterações de humor e psicose.Um dos mais promissores caminhos para tratar esta doença é aumentar o nível de acetilcolina no cérebro usando inibidores da acetilcolinesterase (AChE. Este trabalho teve como objetivo revisar a literatura das plantas e substâncias encontradas nas plantas, inibidores da enzima acetilcolinesterase. Foram levantadas 309 plantas e 260 substâncias isoladas de plantas que foram classificados em grupos químicos adequados, os modelo testados, e suas atividades. Foram consultados 175 referências.

  5. Exploration of the Energy Landscape of Acetylcholinesterase by Molecular Dynamics Simulation.

    McCammon, J. Andrew

    2002-03-01

    Proteins have rough energy landscapes. Often more states than just the ground state are occupied and have biological functions. It is essential to study these conformational substates and the dynamical transitions among them. Acetylcholinesterase (AChE) is an important enzyme that has biological functions including the termination of synaptic transmission signals. X-ray structures show that it has an active site that is accessible only via a long and narrow channel from its surface. Therefore the fact that acetylcholine and larger ligands can reach the active site is believed to reflect the protein's structural fluctuation. We carried out long molecular dynamics simulations to investigate the dynamics of AChE and its relation to biological function, and compared our results with experiments. The results reveal several "doors" that open intermittantly between the active site and the surface. Instead of having simple exponential decay correlation functions, the time series of these channels reveal complex, fractal gating between conformations. We also compared the AChE dynamics data with those from an AchE-fasciculin complex. (Fasciculin is a small protein that is a natural inhibitor of AChE.) The results show remarkable effects of the protein-protein interaction, including allosteric and dynamical inhibition by fasciculin besides direct steric blocking. More information and images can be found at http://mccammon.ucsd.edu

  6. Acetylcholinesterase in central vocal control nuclei of the zebra finch (Taeniopygia guttata)

    Monika Sadananda

    2004-06-01

    The distribution of acetylcholinesterase (AChE) in the central vocal control nuclei of the zebra finch was studied using enzyme histochemistry. AChE fibres and cells are intensely labelled in the forebrain nucleus area X, strongly labelled in high vocal centre (HVC) perikarya, and moderately to lightly labelled in the somata and neuropil of vocal control nuclei robust nucleus of arcopallium (RA), medial magnocellular nucleus of the anterior nidopallium (MMAN) and lateral magnocellular nucleus of the anterior nidopallium (LMAN). The identified sites of cholinergic and/or cholinoceptive neurons are similar to the cholinergic presence in vocal control regions of other songbirds such as the song sparrow, starling and another genus of the zebra finch (Poephila guttata), and to a certain extent in parallel vocal control regions in vocalizing birds such as the budgerigar. AChE presence in the vocal control system suggests innervation by either afferent projecting cholinergic systems and/or local circuit cholinergic neurons. Co-occurrence with choline acetyltransferase (ChAT) indicates efferent cholinergic projections. The cholinergic presence in parts of the zebra finch vocal control system, such as the area X, that is also intricately wired with parts of the basal ganglia, the descending fibre tracts and brain stem nuclei could underlie this circuitry’s involvement in sensory processing and motor control of song.

  7. β-glucan attenuated scopolamine induced cognitive impairment via hippocampal acetylcholinesterase inhibition in rats.

    Haider, Ali; Inam, Wali; Khan, Shahab Ali; Hifza; Mahmood, Wajahat; Abbas, Ghulam

    2016-08-01

    β-glucan (polysaccharide) rich diet has been reported to enhance cognition in humans but the mechanism remained elusive. Keeping this in mind, the present study was designed to investigate the interaction of β-glucan with central cholinergic system. Briefly, in-silico analysis revealed promising interactions of β-glucan with the catalytic residues of acetylcholinesterase (AChE) enzyme. In line with this outcome, the in vitro assay (Ellman's method) also exhibited inhibition of AChE by β-glucan (IC50=0.68±0.08μg/µl). Furthermore, the in vivo study (Morris water maze) showed significant dose dependent reversal of the amnesic effect of scopolamine (2mg/kg i.p.) by β-glucan treatment (5, 25, 50 and 100mg/kg, i.p.). Finally, the hippocampi of aforementioned treated animals also revealed dose dependent inhibition of AChE enzyme. Hence, it can be deduced that β-glucan possesses potential to enhance central cholinergic tone via inhibiting AChE enzyme. In conclusion, the present study provides mechanistic insight to the cognition enhancing potential of β-glucan. Keeping in mind its dietary use and abundance in nature, it can be considered as economic therapeutic option against cognitive ailments associated with decline in cholinergic neurotransmission.

  8. Plant-derived acetylcholinesterase inhibitory alkaloids for the treatment of Alzheimer's disease

    Dall'Acqua S

    2013-01-01

    Full Text Available Stefano Dall'AcquaDepartment of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, ItalyAbstract: The inhibition of acetylcholinesterase (AChE has been one of the most used strategies for the treatment of Alzheimer's disease (AD. The AChE inhibitors (AChE-I produce not only short-term symptomatic effects, but can also play a role in other pathological mechanisms of the disease (eg, formation of amyloid-β plaques, which has renewed interest in the discovery of such inhibitors. Four of the five currently prescribed treatments for AD are AChE-I. Natural alkaloids such as galantamine or alkaloid-related synthetic compounds (such as rivastigmine are considered beneficial for patients with mild-to-moderate AD. However, there is a need for the discovery of more effective compounds and for this reason, plants can still be a potential source of new AChE-I. Findings and advances in knowledge about natural alkaloids as potential new drugs acting as AChE-I will be summarized in this paper.Keywords: quinolizidine, steroidal, indole, isoquinoline

  9. Inhibition of Ptychopetalum olacoides on Acetylcholinesterase Isoforms in Brain of Mice

    FIGUEIR(O) Micheli; POCHMANN Daniela; PORCI(U)NCULA Lisiane Oliveira; NUNES Domingos Sávio; ELISABESTKY Elaine

    2012-01-01

    Objective To further characterize the acetylcholinesterase inhibitors (AChE-Is) pattern of Ptychopetalum olacoides ethanol extract (POEE) on the cytosolic globular monomer (G1) and membrane bound globular tetramer (G4) AChE isoforms in brain areas relevant for cognition.Methods The G1and G4 AChE isoforms were prepared according to the reported methods and the determination of AChE activity used was adapted from colorimetric method.Results POEE mostly inhibited G1in hippocampus (75%),and G4 in frontal cortex (58%) and striatum (75%) (P < 0.05).Kinetic analysis indicated that POEE-induced AChE inhibition in hippocampus was of a competitive nature for G1but uncompetitive for G4.Conclusion Considering the high density of cholinergic projection to the cortex and striatum,and the usefulness of conserving cytosolic acetylcholine to replenish synaptic vesicles in a highly active cognition site such as hippocampus,we argue that this could be a desirable profile for a clinically relevant AChE-I.

  10. Acetylcholinesterase Inhibitors Assay Using Colorimetric pH Sensitive Strips and Image Analysis by a Smartphone

    Adam Kostelnik

    2017-01-01

    Full Text Available Smartphones are widely spread and their usage does not require any trained personnel. Recently, smartphones were successfully used in analytical chemistry as a simple detection tool in some applications. This paper focuses on immobilization of acetylcholinesterase (AChE onto commercially available pH strips with stabilization in the gelatin membrane. AChE degrades acetylcholine into choline and acetic acid which causes color change of acid-base indicator. Smartphone served as a tool for measurement of indicator color change from red to orange while inhibitors blocked this process. AChE inhibitors were measured with limits of detection, 149 nM and 22.3 nM for galanthamine and donepezil, respectively. Organic solvents were measured for method interferences. Measurement procedure was performed on 3D printed holder and digital photography was evaluated using red-green-blue (RGB channels. The invented assay was validated to the standard Ellman’s test and verified on murine plasma samples spiked with inhibitors. We consider that the assay is fully suitable for practical performance.

  11. Surface display of recombinant Drosophila melanogaster acetylcholinesterase for detection of organic phosphorus and carbamate pesticides.

    Jingquan Li

    Full Text Available Acetylcholinesterase (AChE is commonly used for the detection of organophosphate (OP and carbamate (CB insecticides. However, the cost of this commercially available enzyme is high, making high-throughput insecticide detection improbable. In this study we constructed a new AChE yeast expression system in Saccharomyces cerevisiae for the expression of a highly reactive recombinant AChE originating from Drosophila melanogaster (DmAChE. Specifically, the coding sequence of DmAChE was fused with the 3'-terminal half of an α-agglutinin anchor region, along with an antigen tag for the detection of the recombinant protein. The target sequence was cloned into the yeast expression vector pYes-DEST52, and the signal peptide sequence was replaced with a glucoamylase secretion region for induced expression. The resultant engineered vector was transformed into S. cerevisiae. DmAChE was expressed and displayed on the cell surface after galactose induction. Our results showed that the recombinant protein displayed activity comparable to the commercial enzyme. We also detected different types of OP and CB insecticides through enzyme inhibition assays, with the expressed DmAChE showing high sensitivity. These results show the construction of a new yeast expression system for DmAChE, which can subsequently be used for detecting OP and CB insecticides with reduced economic costs.

  12. Effects of carbofuran and deltamethrin on acetylcholinesterase activity in brain and muscle of the common carp.

    Ensibi, Cherif; Hernández-Moreno, David; Míguez Santiyán, M Prado; Daly Yahya, Mohamed Néjib; Rodríguez, Francisco Soler; Pérez-López, Marcos

    2014-04-01

    This work investigated the effect from exposure to insecticides carbofuran and deltamethrin on acetylcholinesterase (AChE) activity in the brain and muscle of common carp (Cyprinus carpio). Both pesticides were evaluated through two separate experiments, and carp were exposed in a semi-static system to three different concentrations of carbofuran (10, 50, and 100 μg/L) and deltamethrin (0.08, 0.4, and 0.8 μg/L) during a month with sampling times at 0, 4, 15, and 30 days (n = 7 from each aquarium). AChE activity was significantly inhibited in both organs of carps exposed to carbofuran at all sampling times depending on dose and time, reaching inhibition values of 73.5 and 67.1%, in brain and muscle tissues respectively, after 30 days with the highest concentration. On the contrary, AChE activity was not significantly affected after deltamethrin exposure at all concentrations and times of the assay. This study shows that the measurement of brain and muscle AChE activity in Cyprinus carpio is a useful biomarker of carbamates exposure and/or effects, but has no application with pyrethroids.

  13. Host-guest complexes and pseudorotaxanes of cucurbit[7]uril with acetylcholinesterase inhibitors.

    Wyman, Ian W; Macartney, Donal H

    2009-11-06

    Pseudorotaxanes may be assembled in aqueous solution using dicationic acetylcholinesterase inhibitors, such as succinylcholine, BW284c51, and alpha,omega-bis(trialkylammonium)alkane dications (or their phosphonium analogues), as bolaform axles and cucurbit[7]uril (CB[7]) as the wheel. With the exceptions of the shorter [(CH(3))(3)N(CH(2))(n)N(CH(3))(3)](2+) (n = 6, 8) dications, the addition of a second CB[7] results in the translocation of the first CB[7], such that the hydrophobic -NR(3)(+) and -PR(3)(+) end groups (R = Me or Et) are located in the cavities of the wheels, while the central portion of the axles extend through the CB[7] portals into the bulk solvent. In the case of the [Quin(CH(2))(10)Quin](2+) (Quin = quinuclidinium) dication, the CB[7] host(s) resides only on the quinuclidinium end group(s). The 1:1 host-guest stability constants range from 8 x 10(6) to 3 x 10(10) M(-1) and are dependent on both the nature of the end group as well as the length and hydrophobicity of the central linker. The magnitude of the stability constants for the 2:1 complexes closely follow the trend observed previously for CB[7] binding with the NR(4)(+) and PR(4)(+) cations.

  14. Novel Triazole-Quinoline Derivatives as Selective Dual Binding Site Acetylcholinesterase Inhibitors

    Susimaire P. Mantoani

    2016-02-01

    Full Text Available Alzheimer’s disease (AD is the most prevalent neurodegenerative disorder worldwide. Currently, the only strategy for palliative treatment of AD is to inhibit acetylcholinesterase (AChE in order to increase the concentration of acetylcholine in the synaptic cleft. Evidence indicates that AChE also interacts with the β-amyloid (Aβ protein, acting as a chaperone and increasing the number and neurotoxicity of Aβ fibrils. It is known that AChE has two binding sites: the peripheral site, responsible for the interactions with Aβ, and the catalytic site, related with acetylcholine hydrolysis. In this work, we reported the synthesis and biological evaluation of a library of new tacrine-donepezil hybrids, as a potential dual binding site AChE inhibitor, containing a triazole-quinoline system. The synthesis of hybrids was performed in four steps using the click chemistry strategy. These compounds were evaluated as hAChE and hBChE inhibitors, and some derivatives showed IC50 values in the micro-molar range and were remarkably selective towards hAChE. Kinetic assays and molecular modeling studies confirm that these compounds block both catalytic and peripheral AChE sites. These results are quite interesting since the triazole-quinoline system is a new structural scaffold for AChE inhibitors. Furthermore, the synthetic approach is very efficient for the preparation of target compounds, allowing a further fruitful new chemical library optimization.

  15. Anti-Acetylcholinesterase and Antioxidant Appraisal of the Bulb Extracts of Five Sternbergia Species

    Ilkay Erdogan Orhan

    2011-01-01

    Full Text Available In the current study, we examined anti-acetylcholinesterase (AChE and antioxidant activities of the ethyl acetate, methanol, and water extracts from the bulbs of Turkish Sternbergia Waldst. & Kit. (Amaryllidaceae species; S. candida, S. clusiana, S. fisheriana, S. lutea subsp. lutea, and S. lutea subsp. sicula. Anti-AChE activity was tested by spectrophotometric method of Ellman using ELISA microplate reader at 50, 100, and 200 μg mL -1 concentrations. Antioxidant activity of the extracts was evaluated by DPPH radical scavenging activity, ferrous ion-chelating capacity, ferric-reducing antioxidant power, and beta-carotene bleaching assays at 500, 1000, and 2000 μg mL -1. Total phenol and flavonoid contents of the extracts were determined via Folin-Ciocalteau’s and AlCl3 reagents, respectively. The ethyl acetate extract of S. fischeriana was the most active in anti-AChE assay (90.94% and 98.02% of inhibitions at 100 and 200 μg mL -1 concentrations, respectively. Antioxidant activity of the extracts was found to be not significant.

  16. Immobilization of acetylcholinesterase on one-dimensional gold nanoparticles for detection of organophosphorous insecticides

    2010-01-01

    This paper reports a simple method for immobilization of acetylcholinesterase (AChE) on one-dimensional (1D) gold (Au) nanoparticles for detection of organophosphorous (OP) insecticides. 1D Au nanoparticles were prepared by electrodeposition in the pores of an alumina template which was subsequently removed by 2.0 M NaOH solution. They were characterized by XRD and FESEM. The immobilized AChE retained its biological activity and catalyzed the hydrolysis of acetylthiocholine to form thiocholine, which was subsequently oxidized to produce detectable signals. Based on the inhibition toward the enzymatic activity of AChE by OP insecticides, sensitive detection of methamidophos (an OP insecticide) was performed. Under optimal conditions, the sensors could be used for the determination of methamidophos ranging from 0.004 to 24 μg/mL with the detection limit of 0.001 μg/mL. The developed OP insecticide biosensors exhibited satisfactory stability and reproducibility. This work demonstrated that 1D Au nanoparticles could serve as an ideal carrier for immobilization of AChE to fabricate the corresponding biosensor.

  17. Acetylcholinesterase Inhibitory, Antioxidant and Phytochemical Properties of Selected Medicinal Plants of the Lamiaceae Family

    Sanda Vladimir-Knežević

    2014-01-01

    Full Text Available The present study aimed to evaluate acetylcholinesterase (AChE inhibitory and antioxidant activities of Lamiaceae medicinal plants growing wild in Croatia. Using Ellman’s colorimetric assay all tested ethanolic extracts and their hydroxycinnamic acid constituents demonstrated in vitro AChE inhibitory properties in a dose dependent manner. The extracts of Mentha x piperita, M. longifolia, Salvia officinalis, Satureja montana, Teucrium arduini, T. chamaedrys, T. montanum, T. polium and Thymus vulgaris at 1 mg/mL showed strong inhibitory activity against AChE. The antioxidant potential of the investigated Lamiaceae species was assessed by DPPH• scavenging activity and total antioxidant capacity assays, in comparison with hydroxycinnamic acids and trolox. The extracts differed greatly in their total hydroxycinnamic derivatives content, determined spectrophotometrically. Rosmarinic acid was found to be the predominant constituent in most of the investigated medicinal plants (by RP-HPLC and had a substantial influence on their AChE inhibitory and antioxidant properties, with the exception of Teucrium species. These findings indicate that Lamiaceae species are a rich source of various natural AChE inhibitors and antioxidants that could be useful in the prevention and treatment of Alzheimer’s and other related diseases.

  18. Trans-acting factors governing acetylcholinesterase mRNA metabolism in neurons

    Lucas M. Bronicki

    2012-03-01

    Full Text Available The most characterized function of acetylcholinesterase (AChE is to terminate cholinergic signaling at neuron-neuron and neuro-muscular synapses. In addition, AChE is causally or casually implicated in neuronal development, stress-response, cognition and neurodegenerative diseases. Given the importance of AChE, many studies have focused on identifying the molecular mechanisms that govern its expression. Despite these efforts, post-transcriptional control of AChE mRNA expression is still relatively unclear. Here, we review the trans-acting factors and cis-acting elements that are known to control AChE pre-mRNA splicing, mature mRNA stability and translation. Moreover, since the Hu/ELAV family of RNA-binding proteins (RBPs have emerged in recent years as ‘master’ post-transcriptional regulators, we discuss the possibility that predominantly neuronal ELAVs (nELAVs play multiple roles in regulating splicing, stability, localization and translation of AChE mRNA.

  19. Finding of polysaccharide-peptide complexes in Cordyceps militaris and evaluation of its acetylcholinesterase inhibition activity

    Cheng-Han Tsai

    2015-03-01

    Full Text Available Acetylcholinesterase (AChE inhibition enhances learning and cognitive ability for treatment of Alzheimer's disease. Polysaccharide–peptide complexes were identified in Cordyceps militaris (CPSPs and characterized for their AChE inhibitory properties. Three polymers (CPSP-F1, -F2, and -F3 were extracted and separated by ultrasound-assisted extraction and diethylaminoethanol (DEAE–Sepharose CL-6B column chromatography. Polysaccharide–peptide complexes were identified by DEAE–Sepharose CL-6B column chromatography and high-performance gel-filtration chromatography, Fourier transform infrared spectra, amino sugar composition analysis, and β-elimination reaction to identify polysaccharide–peptide bond categories. Separation of CPSP can increase AChE inhibitory activity from the crude polysaccharide of C. militaris. CPSP-F1 and CPSP-F2 exhibited half maximal inhibitory concentrations of 32.2 ± 0.2 mg/mL and 5.3 ± 0.0 mg/mL. Thus, we identified polysaccharide–peptide complexes from C. militaris and suggest CPSP has great potential in AChE inhibition bioassay.

  20. Inhibition of acetylcholinesterase and cytochrome oxidase activity in Fasciola gigantica cercaria by phytoconstituents.

    Sunita, Kumari; Habib, Maria; Kumar, P; Singh, Vinay Kumar; Husain, Syed Akhtar; Singh, D K

    2016-02-01

    Fasciolosis is an important cattle and human disease caused by Fasciola hepatica and Fasciola gigantica. One of the possible methods to control this problem is to interrupt the life cycle of Fasciola by killing its larva (redia and cercaria) in host snail. Molecular identification of cercaria larva of F. gigantica was done by comparing the nucleotide sequencing with adult F. gigantica. It was noted that nucleotide sequencing of cercaria larva and adult F. gigantica were 99% same. Every month during the year 2011-2012, in vivo treatment with 60% of 4 h LC50 of phyto cercaricides citral, ferulic acid, umbelliferone, azadirachtin and allicin caused significant inhibition of acetylcholinesterase (AChE) and cytochrome oxidase activity in the treated cercaria larva of F. gigantica. Whereas, activity of both enzymes were not significantly altered in the nervous tissues of vector snail Lymnaea acuminata exposed to same treatments. Maximum reduction in AChE (1.35% of control in month of June) and cytochrome oxidase (3.71% of control in the month of July) activity were noted in the cercaria exposed to 60% of 4 h LC50 of azadirachtin and allicin, respectively.

  1. Expression and characterization of recombinant Locusta migratoria manilensis acetylcholinesterase 1 in Pichia pastoris.

    Zhou, Xiaoxia; Xia, Yuxian

    2011-05-01

    The acetylcholinesterase 1 from Locusta migratoria manilensis (LmAChE1) was successfully expressed in methylotrophic yeast Pichia pastoris KM71. The maximum expression of recombinant LmAChE1 (reLmAChE1) was achieved after 9 days of induction at 2.5% methanol. The reLmAChE1 was first precipitated with ammonium sulfate (50% saturation) and then was purified with nickel affinity chromatography. The enzyme was purified 3.2×10(3)-fold with a yield of 68% and a specific activity of 8.1 U/mg. The purified reLmAChE1 exhibited highest activity at 30°C in 100 mM phosphate buffer (pH 7.4), and its activity could be inhibited by eserine sulfate and pentan-3-one-dibromide (BW284c51). Substrate specificity analysis showed that the purified reLmAChE1 preferred acetylthiocholine (ATC) and propionylthiocholine (BTC) rather than butyrylthiocholine (BTC). When ATC was used as substrate, the K(m) and V(max) values for the reLmAChE1 were 24.8 μM and 9.5 μmol/min/mg, respectively.

  2. Choline-induced selective fluorescence quenching of acetylcholinesterase conjugated Au@BSA clusters.

    Mathew, Meegle S; Baksi, Ananya; Pradeep, T; Joseph, Kuruvilla

    2016-07-15

    We have developed a highly selective sensitive fluorescent detection of acetylcholine (ACh) using bovine serum albumin (BSA) protected atomically precise clusters of gold. The gold quantum clusters (AuQC@BSA) synthesized using bovine serum albumin and conjugated with acetylcholinesterase (AChE), an enzyme specific for acetylcholine, resulting in AuQC@BSA-AChE. The enzyme, AChE hydrolyzes acetylcholine (ACh) to choline (Ch) which in turn interacts with AuQC@BSA-AChE and quenches its fluorescence, enabling sensing. We have carried out the real time monitoring of the hydrolysis of ACh using electrospray ionization mass spectrometry (ESI MS) to find out the mechanism of fluorescent quenching. The validity of present method for determination of concentration of acetylcholine in real system such as blood was demonstrated. Further, the sensor, AuQC@BSA-AChE can be easily coated on paper and an efficient and cheap sensor can be developed and detection limit for ACh is found to be 10nM. The fluorescent intensity of AuQC@BSA-AChE is sensitive towards acetylcholine in range of 10nM to 6.4µM. This suggests that AuQC@BSA-AChE has an excellent potential to be used for diagnosis of various neuropsychological and neuropsychiatric disorders.

  3. [Effect of acetylcholine and acetylcholinesterase on the activity of contractile vacuole of Amoeba proteus].

    Bagrov, Ia Iu; Manusova, N B

    2011-01-01

    Acetylcholine (ACh, 1 microM) stimulates activity of the contractile vacuole of proteus. The effect of ACh is not mimicked by its analogs which are not hydrolyzed by acetylcholinesterase (AChE), i. e., carbacholine and 5-methylfurmethide. The effect of ACh is not sensitive to the blocking action of M-cholinolytics, atropine and mytolone, but is suppressed by N-cholinolytic, tubocurarine. The inhibitors of AChE, eserine (0.01 microM) and armine (0.1 microM), suppress the effect of ACh on amoeba contractile vacuole. ACh does not affect activation of contractile vacuole induced by arginine-vasopressin (1 microM), but it blocks such effect of opiate receptors agonist, dynorphin A1-13 (0.01 microM). This effect of ACh is also suppressed by the inhibitors of AChE. These results suggest that, in the above-described effects of ACh, AChE acts not as an antagonist, but rather as a synergist.

  4. Boron attenuates malathion-induced oxidative stress and acetylcholinesterase inhibition in rats.

    Coban, Funda Karabag; Ince, Sinan; Kucukkurt, Ismail; Demirel, Hasan Huseyin; Hazman, Omer

    2015-10-01

    Organophosphorus compounds cause oxidative stress and lead to alterations in antioxidant status in organisms. In this study, the effects of subchronic exposure to malathion and the protective effects of boron (B) were evaluated in 48 Wistar rats, which were divided equally into six groups. For 28 d, the control group received a normal diet and tap water, the corn oil group received a normal diet and 0.5 mL of corn oil by gastric gavage and the malathion group received a normal diet and malathion (100 mg/kg/d) by gastric gavage. During the same period, each of the three other groups received a different dosage of B (5, 10 and 20 mg/kg/d, respectively) and malathion (100 mg/kg/d) by gastric gavage. Malathion administration during the period increased malondialdehyde, nitric oxide and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels, as well as markers of liver function, yet decreased acetylcholinesterase, reduced glutathione, superoxide dismutase, and catalase activities in blood, liver, kidney and brain tissues. Administration of B in a dose-dependent manner also reversed malathion-induced oxidative stress, lipid peroxidation (LPO) and antioxidant enzyme activity. Moreover, B exhibited protective action against malathion-induced histopathological changes in liver, kidney and brain tissues. These results demonstrate that, if used in a dose-dependent manner, B decreases malathion-induced oxidative stress, enhances the antioxidant defense mechanism and regenerates tissues in rats.

  5. Acetylcholinesterase inhibitory, antioxidant, and antimicrobial activities of Salvia tomentosa Mill. essential oil

    ANDREY MARCHEV

    2015-08-01

    Full Text Available Chemical composition and bioactivity of essential oil from Salvia tomentosa Mill. natively grown in Bulgaria were investigated. GC-MS analysis identified 60 compounds which represented 98% of the oil constituents. The prevalent constituents were monoterpenes with eight dominant compounds being identified: borneol (10.3%, β-pinene (9%, camphor (7.9%, α-pinene (6%, camphene (4%, 1.8-cineole (3.8%, α-limonene (3.5% and β-caryophyllene (3%. The essential oil showed considerable acetylcholinesterase inhibitory activity (IC50=0.28±0.06 µg/mL, comparable with that of galanthamine. Study of antioxidant activity strongly suggested that the hydrogen atom transfer reaction was preferable over the electron transfer (ORAC=175.0±0.40 µM Trolox equivalents/g oil and FRAP=1.45±0.21 mM Trolox equivalents/g oil. The essential oil showed moderate antifungal and antibacterial activities against Candida albicans and Gram-positive bacteria, whereas it was almost inactive against the investigated Gram-negative strains. The results suggested that the essential oil of Bulgarian S. tomentosa could be considered as a prospective active ingredient for prevention of oxidative stress-related and neurodegenerative disorders in aromatherapy. Because of the high antioxidant capacity, the oil could be considered as natural supplement or antioxidant in cosmetics and food products.

  6. Protective Effect of Thunbergia laurifolia (Linn. on Lead Induced Acetylcholinesterase Dysfunction and Cognitive Impairment in Mice

    Moe Pwint Phyu

    2013-01-01

    Full Text Available Thunbergia laurifolia (linn., TL, a natural phenolic compound, has been reported to have many benefits and medicinal properties. The current study ascertains the total phenolic content present in TL aqueous leaf extract and also examines the antioxidant ability of the extract in preserving acetylcholinesterase (AChE activity of mice exposed to lead in vivo and in vitro model. Mice were given lead acetate (Pb in drinking water (1 g/L together with TL 100 and 200 mg/kg/day. The result showed that Pb induced AChE dysfunction in both in vitro and in vivo studies. TL significantly prevented Pb induced neurotoxicity in a dose-dependent manner which was indicated by comparatively better performance of TL treated mice in Morris Water Maze Swimming Test and increased AChE activity in the tissue sample collected from the brains of these mice. TL also exhibited the greatest amount of phenolic content, which has a significant positive correlation with its antioxidant capacity (P<0.05. Taken together, these data suggested that the total phenolic compounds in TL could exhibit antioxidant and in part neuroprotective properties. It may play a potential treatment strategy for Pb contamination.

  7. Coextracted dissolved organic carbon has a suppressive effect on the acetylcholinesterase inhibition assay.

    Neale, Peta A; Escher, Beate I

    2013-07-01

    The acetylcholinesterase (AChE) inhibition assay is frequently applied to detect organophosphates and carbamate pesticides in different water types, including dissolved organic carbon (DOC)-rich wastewater and surface water. The aim of the present study was to quantify the effect of coextracted DOC from different water samples on the commonly used enzyme-based AChE inhibition assay. Approximately 40% to 70% of DOC is typically recovered by solid-phase extraction, and this comprises not only organic micropollutants but also natural organic matter. The inhibition of the water extracts in the assay differed greatly from the expected mixture effects based on chemical analysis of organophosphates and carbamates. Binary mixture experiments with the known AChE inhibitor parathion and the water extracts showed reduced toxicity in comparison with predictions using the mixture models of concentration addition and independent action. In addition, the extracts and reference organic matter had a suppressive effect on a constant concentration of parathion. The present study thus indicated that concentrations of DOC as low as 2 mg carbon/L can impair the AChE inhibition assay and, consequently, that only samples with a final DOC concentration of less than 2 mgC /L are suitable for this assay. To check for potential suppression in environmental samples, standard addition experiments using an AChE-inhibiting reference compound are recommended.

  8. Inhibition of acetylcholinesterase and different ATPases by a novel phosphorothionate (RPR-II) in rat brain.

    Rahman, M F; Siddiqui, M K; Jamil, K

    2000-10-01

    A novel phosphorothionate (2-butenoic acid-3-(diethoxy phosphinothioyl)-methyl ester (RPR-II), synthesized at the Indian Institute of Chemical Technology, Hyderabad, targets its effect on rat brain acetylcholinesterase (AChE) and Na(+)-K(+), Mg(2+), and Ca(2+) ATPases, as evident in this investigation. Three subchronic doses 0.014 (low), 0.028 (medium), and 0.042 (high) mg kg(-1) were administered to rats daily for a period of 90 days RPR-II caused statistically significant dose- and time-dependent inhibition in brain AChE and also in Na(+)-K(+), Mg(2+), and Ca(2+) ATPases in both male and female rats after 45 and 90 days of treatment. The low dose was generally insignificant while the medium and high doses were significantly effective. Females were more susceptible than males with regard to brain AChE, Na(+)-K(+), and Mg(2+) ATPases, which indicates sexual dimorphism in the treated rats. Interestingly, after 28 days post-treatment, recovery of these enzymes was observed. The relative sensitivities of these enzymes indicated that brain AChE was more sensitive than any of the ATPases, but among the ATPases Na(+)-K(+) ATPase was more susceptible than Ca(2+) or Mg(2+) ATPases. This compound, besides inhibiting the target of organophosphates, AChE, also inhibited different ATPases, suggesting both synaptic transmission and nerve conduction were affected.

  9. Luminescent silica nanoparticles for sensing acetylcholinesterase-catalyzed hydrolysis of acetylcholine.

    Mukhametshina, Alsu R; Fedorenko, Svetlana V; Zueva, Irina V; Petrov, Konstantin A; Masson, Patrick; Nizameev, Irek R; Mustafina, Asiya R; Sinyashin, Oleg G

    2016-03-15

    This work highlights the H-function of Tb(III)-doped silica nanoparticles in aqueous solutions of acetic acid as a route to sense acetylcholinesterase-catalyzed hydrolysis of acetylcholine (ACh). The H-function results from H(+)-induced quenching of Tb(III)-centered luminescence due to protonation of Tb(III) complexes located close to silica/water interface. The H-function can be turned on/switched off by the concentration of complexes within core or nanoparticle shell zones, by the silica surface decoration and adsorption of both organic and inorganic cations on silica surface. Results indicate the optimal synthetic procedure for making nanoparticles capable of sensing acetic acid produced by enzymatic hydrolysis of acetylcholine. The H-function of nanoparticles was determined at various concentrations of ACh and AChE. The measurements show experimental conditions for fitting the H-function to Michaelis-Menten kinetics. Results confirm that reliable fluorescent monitoring AChE-catalyzed hydrolysis of ACh is possible through the H-function properties of Tb(III)-doped silica nanoparticles.

  10. Acetylcholinesterase in Biofouling Species: Characterization and Mode of Action of Cyanobacteria-Derived Antifouling Agents.

    Almeida, Joana R; Freitas, Micaela; Cruz, Susana; Leão, Pedro N; Vasconcelos, Vitor; Cunha, Isabel

    2015-07-24

    Effective and ecofriendly antifouling (AF) compounds have been arising from naturally produced chemicals. The objective of this study is to use cyanobacteria-derived agents to investigate the role of acetylcholinesterase (AChE) activity as an effect and/or mode of action of promising AF compounds, since AChE inhibitors were found to inhibit invertebrate larval settlement. To pursue this objective, in vitro quantification of AChE activity under the effect of several cyanobacterial strain extracts as potential AF agents was performed along with in vivo AF (anti-settlement) screening tests. Pre-characterization of different cholinesterases (ChEs) forms present in selected tissues of important biofouling species was performed to confirm the predominance of AChE, and an in vitro AF test using pure AChE activity was developed. Eighteen cyanobacteria strains were tested as source of potential AF and AChE inhibitor agents. Results showed effectiveness in selecting promising eco-friendly AF agents, allowing the understanding of the AF biochemical mode of action induced by different compounds. This study also highlights the potential of cyanobacteria as source of AF agents towards invertebrate macrofouling species.

  11. Nanomaterials - Acetylcholinesterase Enzyme Matrices for Organophosphorus Pesticides Electrochemical Sensors: A Review

    Shen-Ming Chen

    2009-05-01

    Full Text Available Acetylcholinesterase (AChE is an important cholinesterase enzyme present in the synaptic clefts of living organisms. It maintains the levels of the neurotransmitter acetylcholine by catalyzing the hydrolysis reaction of acetylcholine to thiocholine. This catalytic activity of AChE is drastically inhibited by trace amounts of organophosphorus (OP pesticides present in the environment. As a result, effective monitoring of OP pesticides in the environment is very desirable and has been done successfully in recent years with the use of nanomaterial-based AChE sensors. In such sensors, the enzyme AChE has been immobilized onto nanomaterials like multiwalled carbon nanotubes, gold nanoparticles, zirconia nanoparticles, cadmium sulphide nano particles or quantum dots. These nanomaterial matrices promote significant enhancements of OP pesticide determinations, with the thiocholine oxidation occurring at much lower oxidation potentials. Moreover, nanomaterial-based AChE sensors with rapid response, increased operational and long storage stability are extremely well suited for OP pesticide determination over a wide concentration range. In this review, the unique advantages of using nanomaterials as AChE immobilization matrices are discussed. Further, detection limits, sensitivities and correlation coefficients obtained using various electroanalytical techniques have also been compared with chromatographic techniques.

  12. Formulation and characterization of novel functional beverages with antioxidant and anti-acetylcholinesterase activities

    Suree Nanasombat

    2015-01-01

    beverages B1, B2, B3, B4 and B5 in the ratio of 60:40 to prepare alcoholic beverages W1, W2, W3, W4 and W5, respectively. Two different fermentation conditions (fermentation with or without pieces of sliced medicinal plant residue, PMPR were compared. After fermenting, racking and aging, all alcoholic beverages, as well as all non-alcoholic beverages,were analyzed for some phytochemical properties. Results: Grape fermented with PMPR had higher anti-acetylcholinesterase and antioxidant activities, and total phenolics, flavonoids and tannins, compared to the others. Among all nonalcoholic beverages, the beverage B3 contained the highest anti-acetylcholinesterase (22.78% inhibition at 1:10,000 dilution and antioxidant activities (reducing capacity, 4.22 mmol Fe(II/100 mL, total phenolics, flavonoids, and tannins (494.44 mg gallic acid equivalents (GAE, 383.22 mg catechin equivalents (CE and 338.29 mg tannic acid equivalents ((TAE/100 mL, respectively. Among all alcoholic beverages, the beverage W3 (fermented with PMPR exhibited the highest antioxidant activity (DPPH radical inhibition, 95.99 mg trolox equivalents and reducing capacity, 3.57 mmol Fe(II /100 mL, total phenolics, flavonoids and tannins (239.71 mg GAE, 372.67 mg CE and 157.67 mg TAE/100 mL, respectively. The beverage W2 (fermented with PMPR had the highest anti-acetylcholinesterase activity (21.35% inhibition at 1:10,000 dilution. Conclusion: The beverages B3, W2 and W3 contained valuable sources of natural antioxidants and acetylcholinesterase inhibitors, and may provide health benefits when consumed.

  13. Characterization of Lignanamides from Hemp (Cannabis sativa L.) Seed and Their Antioxidant and Acetylcholinesterase Inhibitory Activities.

    Yan, Xiaoli; Tang, Jiajing; dos Santos Passos, Carolina; Nurisso, Alessandra; Simões-Pires, Claudia Avello; Ji, Mei; Lou, Hongxiang; Fan, Peihong

    2015-12-16

    Hemp seed is known for its content of fatty acids, proteins, and fiber, which contribute to its nutritional value. Here we studied the secondary metabolites of hemp seed aiming at identifying bioactive compounds that could contribute to its health benefits. This investigation led to the isolation of 4 new lignanamides, cannabisin M (2), cannabisin N (5), cannabisin O (8), and 3,3'-demethyl-heliotropamide (10), together with 10 known lignanamides, among which 4 was identified for the first time from hemp seed. Structures were established on the basis of NMR, HR-MS, UV, and IR as well as by comparison with the literature data. Lignanamides 2, 7, and 9-14 showed good antioxidant activity, among which 7, 10, and 13 also inhibited acetylcholinesterase in vitro. The newly identified compounds in this study add to the diversity of hemp seed composition, and the bioassays implied that hemp seed, with lignanamides as nutrients, may be a good source of bioactive and protective compounds.

  14. Carbon-11 labelling of an inhibitor of acetylcholinesterase: [[sup 11]C]physostigmine

    Bonnot-Lours, S.; Crouzel, C.; Prenant, C.; Hinnen, F. (CEA, 91 - Orsay (France). Service Hospitalier Frederic Joliot)

    1993-01-01

    Physostigmine, an alkaloid from calabar bean is a strong inhibitor of acetylcholinesterase and has been used clinically in the treatment of glaucoma, atropine intoxication, myasthenia gravis and more recently, in experimental trials in Alzheimer's disease. In order to study the AChE activity in the brain by positron emission tomography, we have undertaken the labelling of physostigmine with carbon-11. The synthesis involves the reaction of [[sup 11]C]methylisocyanate with eseroline. [[sup 11]C]Methylisocyanate was obtained by heating [[sup 11]C]acetylchloride with tetrabutylammonium azide in toluene. The synthesis of [[sup 11]C]CH[sub 3]COC1 involves the carbonation of methylmagnesium bromide in THF with cyclotron produced [[sup 11]C]carbon dioxide and the addition of phthaloyl dichloride. The [[sup 11]C]methylisocyanate is distilled into a solution of eseroline in ether with a small piece of sodium. After 10 minutes at 25[sup o]C, the solution is purified by HPLC and the appropriate fraction collected. Starting with 55.5 GBq (1.5 Ci) of [[sup 11]C]carbon dioxide, 0.92-1.48 GBq (25-40 mCi) of [[sup 11]C]Physostigmine are obtained 57 minutes after EOB. (author).

  15. Triterpenoids with acetylcholinesterase inhibition from Chuquiraga erinacea D. Don. subsp. erinacea (Asteraceae).

    Gurovic, María Soledad; Castro, María Julia; Richmond, Victoria; Faraoni, María Belén; Maier, Marta S; Murray, Ana Paula

    2010-04-01

    A bioactivity-guided approach was taken to identify the acetylcholinesterase (AChE) inhibitory agents in the ethanolic extract of Chuquiraga erinacea D. Don. subsp. erinacea leaves using a bioautographic method. This permitted the isolation of the pentacyclic triterpenes calenduladiol (1), faradiol (2), heliantriol B2 (3), lupeol (4), and a mixture of alpha-and beta-amyrin ( 5A and 5B) as active constituents. Pseudotaraxasterol (6) and taraxasterol (7) were also isolated from this extract and showed no activity at the same analytical conditions. Compound 1 showed the highest AChE inhibitory activity with 31.2 % of inhibition at 0.5 mM. Looking forward to improve the water solubility of the active compounds, the sodium sulfate ester of 1 was prepared by reaction with the (CH3)3N.SO3 complex. The semisynthetic derivative disodium calenduladiol disulfate (8) elicited higher AChE inhibition than 1 with 94.1 % of inhibition at 0.5 mM (IC (50) = 0.190 +/- 0.003 mM). Compounds 1, 2, 3, 5, 6, and 7 are reported here for the first time in C. erinacea. This is the first report of AChE inhibition from calenduladiol (1) as well as from a sulfate derived from a natural product.

  16. Investigation of kinetic interactions between approved oximes and human acetylcholinesterase inhibited by pesticide carbamates.

    Wille, Timo; Kaltenbach, Lisa; Thiermann, Horst; Worek, Franz

    2013-12-01

    Carbamates are widely used for pest control and act primarily by inhibition of insect and mammalian acetylcholinesterase (AChE). Accidental or intentional uptake of carbamates may result in typical signs and symptoms of cholinergic overstimulation which cannot be discriminated from those of organophosphorus pesticide poisoning. There is an ongoing debate whether standard treatment with atropine and oximes should be recommended for human carbamate poisoning as well, since in vitro and in vivo animal data indicate a deleterious effect of oximes when used in combination with the N-methyl carbamate carbaryl. Therefore, we performed an in vitro kinetic study to investigate the effect of clinically used oximes on carbamoylation and decarbamoylation of human AChE. It became evident that pralidoxime and obidoxime in therapeutic concentrations aggravate the inhibition of AChE by carbaryl and propoxur, with obidoxime being substantially more potent compared to 2-PAM. However, obidoxime had no impact on the decarbamoylation kinetics. Hence, the administration of 2-PAM and especially of obidoxime to severely propoxur and carbaryl poisoned humans cannot be recommended.

  17. In vitro Evaluation of New Acetylcholinesterase Reactivators as Casual Antidotes against Tabun and Cyclosarin

    Kuca, Kamil; Jun, Daniel; Jung, Young Sik [Faculty of Military Health Sciences, Trebesska (Cyprus); Kim, Tae Hyuk; Cabal, Jiri [Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of)

    2006-03-15

    Nerve agents (sarin, tabun, soman and VX) are class of military important substances able to cause many severe intoxications during few minutes. Currently, the threat of misuse of these agents is daily discussed. Unfortunately, there is no single antidote able to treat intoxication caused by all of these agents. Owing to this fact, new generation of antidotes, especially acetylcholinesterase (AChE: EC 3.1.1.7) reactivators, is still developed. In this study, we have tested four newly developed AChE reactivators: 1-(4-hydroxyiminomethylpyridinium)- 5-(4-carbamoylpyridinium)-3-oxa-pentane dibromide (1), 1-(3-hydroxyiminomethylpyridinium)- 5-(4-carbamoylpyridinium)-3-oxa-pentane dibromide (2), 1,5-bis(2-hydroxyiminomethylpyridinium)- 3-oxa-pentane dichloride (3) and 1,5-bis(4-hydroxyiminomethylpyridinium)-3-oxa-pentane dibromide (4) for their potency to reactivate in vitro tabun and cyclosarin-inhibited AChE. Their reactivation efficacy was compared with currently the most promising oxime HI-6 (1-(2-hydroxyiminomethylpyridinium)-3-(4- carbamoylpyridinium)-2-oxa-propane dichloride). According to obtained results, two AChE reactivators 1 and 4 were able to reactivate tabun-inhibited AChE. On the contrary, there was no better AChE reactivator than HI- 6 able to reactivate cyclosarin-inhibited AChE.

  18. [A comparison of the efficacy of the reactivators of acetylcholinesterase inhibited with tabun].

    Cabal, J; Kuca, K; Jun, D; Bajgar, J; Hrabinová, M

    2005-07-01

    The nerve agent tabun inhibits acetylcholinesterase (AChE; EC 3.1.1.7) by the formation of a covalent bond with the enzyme. Afterwards, AChE is not able to fulfil its role in the organism and subsequently cholinergic crisis occurs. AChE reactivators (pralidoxime, obidoxime and HI-6) as causal antidotes are used for the cleavage of the bond between the enzyme and nerve agent. Unfortunately, their potency for reactivation of tabun-inhibited AChE is poor. The aim of the study was to choose the most potent reactivator of tabun-inhibited AChE. We have tested eight AChE reactivators--pralidoxime, obidoxime, trimedoxime, HI-6, methoxime, Hlö-7 and our newly synthesized oximes K027 and K048. All reactivators were tested using our standard in vitro reactivation test (pH 8, 25 degrees C, time of inhibition by the nerve agent 30 minutes, time of reactivation by AChE reactivator 10 minutes). According to our results, only trimedoxime was able to achieve 50% reactivation potency. However, this relatively high potency was achieved at high oxime concentration (10(-2) M). At a lower concentration of 10(-4) M (the probably attainable concentration in vivo), four AChE reactivators (trimedoxime, obidoxime, K027, and K048) were able to reactivate AChE inhibited by tabun reaching from 10 to 18%.

  19. An Acetylcholinesterase-Based Chronoamperometric Biosensor for Fast and Reliable Assay of Nerve Agents

    Rene Kizek

    2013-08-01

    Full Text Available The enzyme acetylcholinesterase (AChE is an important part of cholinergic nervous system, where it stops neurotransmission by hydrolysis of the neurotransmitter acetylcholine. It is sensitive to inhibition by organophosphate and carbamate insecticides, some Alzheimer disease drugs, secondary metabolites such as aflatoxins and nerve agents used in chemical warfare. When immobilized on a sensor (physico-chemical transducer, it can be used for assay of these inhibitors. In the experiments described herein, an AChE- based electrochemical biosensor using screen printed electrode systems was prepared. The biosensor was used for assay of nerve agents such as sarin, soman, tabun and VX. The limits of detection achieved in a measuring protocol lasting ten minutes were 7.41 × 10−12 mol/L for sarin, 6.31 × 10−12 mol /L for soman, 6.17 × 10−11 mol/L for tabun, and 2.19 × 10−11 mol/L for VX, respectively. The assay was reliable, with minor interferences caused by the organic solvents ethanol, methanol, isopropanol and acetonitrile. Isopropanol was chosen as suitable medium for processing lipophilic samples.

  20. Alkaloids from Peumus boldus and their acetylcholinesterase, butyrylcholinesterase and prolyl oligopeptidase inhibition activity.

    Hošt'álková, Anna; Opletal, Lubomír; Kuneš, Jiří; Novák, Zdeněk; Hrabinová, Martina; Chlebek, Jakub; Čegan, Lukáš; Cahlíková, Lucie

    2015-04-01

    Eleven isoquinoline alkaloids (1-11) were isolated from dried leaves of Peumus boldus Mol. by standard chromatographic methods. The chemical structures were elucidated by MS, and 1D and 2D NMR spectroscopic analysis, and by comparison with literature data. Compounds isolated in sufficient amount were evaluated for their acetylcholinesterase, and butyrylcholinesterase inhibition activity using Ellman's method. In the prolyl oligopeptidase assay, Z-Gly-Pro-p-nitroanilide was used as substrate. Promising butyrylcholinesterase inhibition activities were demonstrated by two benzylisoquinoline alkaloids, reticuline (8) and N-methylcoclaurine (9), with IC50 values of 33.6 ± 3.0 µM and 15.0 ± 1.4 µM, respectively. Important prolyl oligopeptidase inhibition activities were shown by N-methyllaurotetanine (6) and sinoacutine (4) with IC50 values of 135.4 ± 23.2 µM and 143.1 ± 25.4 µM, respectively. Other tested compounds were considered inactive.

  1. Acetylcholinesterase inhibition and micronucleus frequency in oysters (Crassostrea corteziensis exposed to chlorpyrifos

    AB Benitez-Trinidad1

    2014-09-01

    Full Text Available Chlorpyrifos (CPF is an Organophosphorous pesticide (OP that has been widely used for both agricultural and domestic pest control. To date, there is little information regarding the effects of this pesticide on aquatic organisms, particularly oysters. The aim of this study was to evaluate Acetylcholinesterase (AChE activity and Micronucleus (MN frequency in the oyster Crassostrea corteziensis in laboratory exposure with CPF (20, 40, 60, 80, and 160 μg/L and in a field study. The results showed that AChE was reduced 60 - 82 % in oysters exposed to CPF, relative to the negative control. Similar AChE results were observed in oysters collected from the Boca de Camichín Estuary in Nayarit, Mexico; with respect to genetic damage, evaluated through MN, treatment with CPF did not induce the MN frequency, nor did the oyster from the field study exhibit an increase in this biomarker. These results suggest that C. corteziensis is a sensitive model for evaluating the acute toxicity of OP in laboratory studies as well in the field. In addition, it generates prospects on studying mechanisms through which the oyster could possess resistance to genotoxic agents, as well as its being a reliable model for evaluating the genotoxic effects of xenobiotics through the MN technique.

  2. Effect of pesticide exposure on acetylcholinesterase activity in subsistence farmers from Campeche, Mexico.

    Rendón von Osten, Jaime; Epomex, Centro; Tinoco-Ojanguren, Rolando; Soares, Amadeu M V M; Guilhermino, Lucia

    2004-08-01

    The authors surveyed agricultural production methods and pesticide use among subsistence farmers (campesinos) in 4 rural communities of Campeche, Mexico. Self-reports of symptoms of poisoning resulting from occupational pesticide exposure were elicited by questionnaire (N = 121), and acetylcholinesterase (AChE) activity during insecticide use was evaluated from blood samples (N = 127). In individuals from 2 of the 4 communities, AChE activity was significantly lower (p < 0.05) than the mean of activity determined for individuals in a reference group. Results of this study show that erythrocyte AChE inhibition provides a good biomarker of exposure to organophosphate pesticides in field studies with human populations. Carbamates, particularly carbofuran, seem to be more associated with exuberant and diversified symptomatology of pesticide exposure than organophosphates. Studies in field communities where both carbamates and organophosphates are suspected to exist should include blood AChE determinations, symptomatology surveys, and socioeconomic questionnaires. The authors recommend that the Mexican National Health Ministry authorities specify additional provisions regarding the use of protective equipment and the adoption of other safety practices during field work, increase information campaigns about the risks of pesticide use and the value of safety practices, and increase programs of medical monitoring and assistance for rural communities dealing with pesticides.

  3. Morphometry and acetylcholinesterase activity of the myenteric plexus of the wild mouse Calomys callosus

    L.B.M. Maifrino

    1997-05-01

    Full Text Available The myenteric plexus of the digestive tract of the wild mouse Calomys callosus was examined using a histochemical method that selectively stains nerve cells, and the acetylcholinesterase (AChE histochemical technique in whole-mount preparations. Neuronal density was 1,500 ± 116 neurons/cm2 (mean ± SEM in the esophagus, 8,900 ± 1,518 in the stomach, 9,000 ± 711 in the jejunum and 13,100 ± 2,089 in the colon. The difference in neuronal density between the esophagus and other regions was statistically significant. The neuron profile area ranged from 45 to 1,100 µm2. The difference in nerve cell size between the jejunum and other regions was statistically significant. AChE-positive nerve fibers were distributed within the myenteric plexus which is formed by a primary meshwork of large nerve bundles and a secondary meshwork of finer nerve bundles. Most of the nerve cells displayed AChE activity in the cytoplasm of different reaction intensities. These results are important in order to understand the changes occurring in the myenteric plexus in experimental Chagas' disease

  4. Endosulfan induces changes in spontaneous swimming activity and acetylcholinesterase activity of Jenynsia multidentata (Anablepidae, Cyprinodontiformes)

    Ballesteros, M.L. [Facultad de Ciencias Exactas, Fisicas y Naturales, Catedra Diversidad Animal II, Universidad Nacional de Cordoba, Av. Velez Sarsfield 299, 5000 Cordoba (Argentina); Durando, P.E. [Facultad de Ciencias Exactas, Fisicas y Naturales, Departamento de Biologia, Catedra de Fisiologia Animal, Universidad Nacional de San Juan, Complejo ' Islas Malvinas' , Av. Jose I. de la Roza y Meglioli, Rivadavia, San Juan (Argentina); Nores, M.L. [Facultad de Ciencias Medicas, Universidad Nacional de Cordoba-CONICET, Ciudad Universitaria, Cordoba (Argentina); Diaz, M.P. [Facultad de Ciencias Medicas, Catedra de Estadistica y Bioestadistica, Escuela de Nutricion, Universidad Nacional de Cordoba, Pabellon Chile, Ciudad Universitaria, 5000 Cordoba (Argentina); Bistoni, M.A., E-mail: mbistoni@com.uncor.ed [Facultad de Ciencias Exactas, Fisicas y Naturales, Catedra Diversidad Animal II, Universidad Nacional de Cordoba, Av. Velez Sarsfield 299, 5000 Cordoba (Argentina); Wunderlin, D.A. [Facultad de Ciencias Quimicas, Dto. Bioquimica Clinica-CIBICI, Universidad Nacional de Cordoba-CONICET, Haya de la Torre esq. Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2009-05-15

    We assessed changes in spontaneous swimming activity and acetylcholinesterase (AchE) activity of Jenynsia multidentata exposed to Endosulfan (EDS). Females of J. multidentata were exposed to 0.072 and 1.4 mug L{sup -1} EDS. Average speed and movement percentage were recorded during 48 h. We also exposed females to EDS at five concentrations between 0.072 and 1.4 mug L{sup -1} during 24 h, and measured the AchE activity in brain and muscle. At 0.072 mug L{sup -1} EDS swimming motility decreased relative to the control group after 45 h, while at 1.4 mug L{sup -1} EDS swimming motility decreased after 24 h. AchE activity significantly decreased in muscle when J. multidentata were exposed to EDS above 0.072 mug L{sup -1}, while no significant changes were observed in brain. Thus, changes in swimming activity and AchE activity in muscle are good biomarkers of exposure to EDS in J. multidentata. - This work reports changes observed in spontaneous swimming activity and AchE activity of Jenynsia multidentata exposed to sublethal concentrations of Endosulfan.

  5. Acetylcholinesterase inhibitory activity of Thai traditional nootropic remedy and its herbal ingredients.

    Tappayuthpijarn, Pimolvan; Itharat, Arunporn; Makchuchit, Sunita

    2011-12-01

    The incidence of Alzheimer disease (AD) is increasing every year in accordance with the increasing of elderly population and could pose significant health problems in the future. The use of medicinal plants as an alternative prevention or even for a possible treatment of the AD is, therefore, becoming an interesting research issue. Acetylcholinesterase (AChE) inhibitors are well-known drugs commonly used in the treatment of AD. The aim of the present study was to screen for AChE inhibitory activity of the Thai traditional nootropic recipe and its herbal ingredients. The results showed that ethanolic extracts of four out of twenty-five herbs i.e. Stephania pierrei Diels. Kaempfera parviflora Wall. ex Baker, Stephania venosa (Blume) Spreng, Piper nigrum L at 0.1 mg/mL showed % AChE inhibition of 89, 64, 59, 50; the IC50 were 6, 21, 29, 30 microg/mL respectively. The other herbs as well as combination of the whole recipe had no synergistic inhibitory effect on AChE activity. However some plants revealed antioxidant activity. More research should have be performed on this local wisdom remedy to verify the uses in scientific term.

  6. Neuromuscular Junction Impairment in Amyotrophic Lateral Sclerosis: Reassessing the Role of Acetylcholinesterase

    Campanari, Maria-Letizia; García-Ayllón, María-Salud; Ciura, Sorana; Sáez-Valero, Javier; Kabashi, Edor

    2016-01-01

    Amyotrophic Lateral Sclerosis (ALS) is a highly debilitating disease caused by progressive degeneration of motorneurons (MNs). Due to the wide variety of genes and mutations identified in ALS, a highly varied etiology could ultimately converge to produce similar clinical symptoms. A major hypothesis in ALS research is the “distal axonopathy” with pathological changes occurring at the neuromuscular junction (NMJ), at very early stages of the disease, prior to MNs degeneration and onset of clinical symptoms. The NMJ is a highly specialized cholinergic synapse, allowing signaling between muscle and nerve necessary for skeletal muscle function. This nerve-muscle contact is characterized by the clustering of the collagen-tailed form of acetylcholinesterase (ColQ-AChE), together with other components of the extracellular matrix (ECM) and specific key molecules in the NMJ formation. Interestingly, in addition to their cholinergic role AChE is thought to play several “non-classical” roles that do not require catalytic function, most prominent among these is the facilitation of neurite growth, NMJ formation and survival. In all this context, abnormalities of AChE content have been found in plasma of ALS patients, in which AChE changes may reflect the neuromuscular disruption. We review these findings and particularly the evidences of changes of AChE at neuromuscular synapse in the pre-symptomatic stages of ALS. PMID:28082868

  7. Effects of chlorophenoxy herbicides and their main transformation products on DNA damage and acetylcholinesterase activity.

    Benfeito, Sofia; Silva, Tiago; Garrido, Jorge; Andrade, Paula B; Sottomayor, M J; Borges, Fernanda; Garrido, E Manuela

    2014-01-01

    Persistent pesticide transformation products (TPs) are increasingly being detected among different environmental compartments, including groundwater and surface water. However, there is no sufficient experimental data on their toxicological potential to assess the risk associated with TPs, even if their occurrence is known. In this study, the interaction of chlorophenoxy herbicides (MCPA, mecoprop, 2,4-D and dichlorprop) and their main transformation products with calf thymus DNA by UV-visible absorption spectroscopy has been assessed. Additionally, the toxicity of the chlorophenoxy herbicides and TPs was also assessed evaluating the inhibition of acetylcholinesterase activity. On the basis of the results found, it seems that AChE is not the main target of chlorophenoxy herbicides and their TPs. However, the results found showed that the transformation products displayed a higher inhibitory activity when compared with the parent herbicides. The results obtained in the DNA interaction studies showed, in general, a slight effect on the stability of the double helix. However, the data found for 4-chloro-2-methyl-6-nitrophenol suggest that this transformation product can interact with DNA through a noncovalent mode.

  8. Effects of Chlorophenoxy Herbicides and Their Main Transformation Products on DNA Damage and Acetylcholinesterase Activity

    Sofia Benfeito

    2014-01-01

    Full Text Available Persistent pesticide transformation products (TPs are increasingly being detected among different environmental compartments, including groundwater and surface water. However, there is no sufficient experimental data on their toxicological potential to assess the risk associated with TPs, even if their occurrence is known. In this study, the interaction of chlorophenoxy herbicides (MCPA, mecoprop, 2,4-D and dichlorprop and their main transformation products with calf thymus DNA by UV-visible absorption spectroscopy has been assessed. Additionally, the toxicity of the chlorophenoxy herbicides and TPs was also assessed evaluating the inhibition of acetylcholinesterase activity. On the basis of the results found, it seems that AChE is not the main target of chlorophenoxy herbicides and their TPs. However, the results found showed that the transformation products displayed a higher inhibitory activity when compared with the parent herbicides. The results obtained in the DNA interaction studies showed, in general, a slight effect on the stability of the double helix. However, the data found for 4-chloro-2-methyl-6-nitrophenol suggest that this transformation product can interact with DNA through a noncovalent mode.

  9. Molecular evaluation of herbal compounds as potent inhibitors of acetylcholinesterase for the treatment of Alzheimer's disease.

    Chen, Yan-Xiu; Li, Guan-Zeng; Zhang, Bin; Xia, Zhang-Yong; Zhang, Mei

    2016-07-01

    Alzheimer's disease (AD) is a progressive disease and the predominant cause of dementia. Common symptoms include short-term memory loss, and confusion with time and place. Individuals with AD depend on their caregivers for assistance, and may pose a burden to them. The acetylcholinesterase (AChE) enzyme is a key target in AD and inhibition of this enzyme may be a promising strategy in the drug discovery process. In the present study, an inhibitory assay was carried out against AChE using total alkaloidal plants and herbal extracts commonly available in vegetable markets. Subsequently, molecular docking simulation analyses of the bioactive compounds present in the plants were conducted, as well as a protein‑ligand interaction analysis. The stability of the docked protein‑ligand complex was assessed by 20 ns molecular dynamics simulation. The inhibitory assay demonstrated that Uncaria rhynchophylla and Portulaca oleracea were able to inhibit AChE. In addition, molecular docking simulation analyses indicated that catechin present in Uncaria rhynchophylla, and dopamine and norepinephrine present in Portulaca oleracea, had the best docking scores and interaction energy. In conclusion, catechin in Uncaria rhynchophylla, and dopamine and norepinephrine in Portulaca oleracea may be used to treat AD.

  10. Structure of acetylcholinesterase complexed with (-)-galanthamine at 2.3 A resolution.

    Greenblatt, H M; Kryger, G; Lewis, T; Silman, I; Sussman, J L

    1999-12-17

    (-)-Galanthamine (GAL), an alkaloid from the flower, the common snowdrop (Galanthus nivalis), shows anticholinesterase activity. This property has made GAL the target of research as to its effectiveness in the treatment of Alzheimer's disease. We have solved the X-ray crystal structure of GAL bound in the active site of Torpedo californica acetylcholinesterase (TcAChE) to 2.3 A resolution. The inhibitor binds at the base of the active site gorge of TcAChE, interacting with both the choline-binding site (Trp-84) and the acyl-binding pocket (Phe-288, Phe-290). The tertiary amine group of GAL does not interact closely with Trp-84; rather, the double bond of its cyclohexene ring stacks against the indole ring. The tertiary amine appears to make a non-conventional hydrogen bond, via its N-methyl group, to Asp-72, near the top of the gorge. The hydroxyl group of the inhibitor makes a strong hydrogen bond (2.7 A) with Glu-199. The relatively tight binding of GAL to TcAChE appears to arise from a number of moderate to weak interactions with the protein, coupled to a low entropy cost for binding due to the rigid nature of the inhibitor.

  11. acetylcholinesterase inhibitory potential and insecticidal activity of an endophytic Alternaria sp. from Ricinus communis.

    Singh, Bahaderjeet; Thakur, Abhinay; Kaur, Sanehdeep; Chadha, B S; Kaur, Amarjeet

    2012-11-01

    Keeping in view the vast potential of endophytic fungi to produce bioactive molecules, this study aimed at isolating and screening endophytes for the production of acetylcholinesterase inhibitors. Fifty-four endophytic fungi were isolated from Ricinus communis and screened for their AChE inhibitory activity using Ellman's colorimetric assay method. Six isolates were found to possess AChE inhibitory activity with maximum inhibition of 78 % being evinced by culture Cas1 which was identified to be Alternaria sp. on the basis of molecular as well as microscopic methods. Optimization of inhibitor production was carried out using one factor at a time approach. Maximum production of inhibitor was obtained on potato dextrose broth after 10 days incubation. The IC(50) of the chloroform extract was observed to be 40 μg/ml. The extract was purified on silica gel and eluted stepwise with a gradient of chloroform/methanol. The insecticidal potential of the extract was evaluated by feeding the larvae of Spodoptera litura on diet containing varying concentrations of the extract. It was observed that with increase in the concentration of the extract, mortality of the larvae increased. The culture has the potential of being exploited in medicine as well as a biocontrol agent.

  12. The visual pulvinar in tree shrews I. Multiple subdivisions revealed through acetylcholinesterase and Cat-301 chemoarchitecture.

    Lyon, David C; Jain, Neeraj; Kaas, Jon H

    2003-12-22

    Tree shrews are highly visual mammals closely related to primates. They have a large visual pulvinar complex, but its organization and relation to visual cortex is only partly known. We processed brain sections through the pulvinar with seven different procedures in an effort to reveal histologically distinct compartments. The results revealed three major subdivisions. A dorsal subdivision, Pd, stains darkly for acetylcholinesterase (AChE) and occupies the dorsoposterior one-third of the pulvinar complex. A ventral subdivision, Pv, stains darkly when processed with the Cat-301 antibody and occupies the ventroanterior fifth of the pulvinar complex along the brachium of the superior colliculus. Unexpectedly, part of Pv is ventral to the brachium. A large central subdivision, Pc, stains moderately dark for AChE and cytochrome oxidase (CO), and very light for Cat-301. Pc includes about half of the pulvinar complex, with parts on both sides of the brachium of the superior colliculus. These architectonic results demonstrate that the pulvinar complex of tree shrews is larger and has more subdivisions than previously described. The complex resembles the pulvinar of primates by having a portion ventral to the brachium and by having histochemically distinct nuclei; the number of nuclei is less than in primates, however.

  13. Expression of acetylcholinesterase 1 is associated with brood rearing status in the honey bee, Apis mellifera

    Kim, Young Ho; Kim, Ju Hyeon; Kim, Kyungmun; Lee, Si Hyeock

    2017-01-01

    Acetylcholinesterase 1 (AmAChE1) of the honey bee, Apis mellifera, has been suggested to have non-neuronal functions. A systematic expression profiling of AmAChE1 over a year-long cycle on a monthly basis revealed that AmAChE1 was predominantly expressed in both head and abdomen during the winter months and was moderately expressed during the rainy summer months. Interestingly, AmAChE1 expression was inhibited when bees were stimulated for brood rearing by placing overwintering beehives in strawberry greenhouses with a pollen diet, whereas it resumed when the beehives were moved back to the cold field, thereby suppressing brood rearing. In early spring, pollen diet supplementation accelerated the induction of brood-rearing activity and the inhibition of AmAChE1 expression. When active beehives were placed in a screen tent in late spring, thereby artificially suppressing brood-rearing activity, AmAChE1 was highly expressed. In contrast, AmAChE1 expression was inhibited when beehives were allowed to restore brood rearing by removing the screen, supporting the hypothesis that brood rearing status is a main factor in the regulation of AmAChE1 expression. Since brood rearing status is influenced by various stress factors, including temperature and diet shortage, our finding discreetly suggests that AmAChE1 is likely involved in the stress response or stress management. PMID:28045085

  14. Lesions of rat skeletal muscle after local block of acetylcholinesterase and neuromuscular stimulation.

    Mense, S; Simons, D G; Hoheisel, U; Quenzer, B

    2003-06-01

    In skeletal muscle, a local increase of acetylcholine (ACh) in a few end plates has been hypothesized to cause the formation of contraction knots that can be found in myofascial trigger points. To test this hypothesis in rats, small amounts of an acetylcholinesterase inhibitor [diisopropylfluorophosphate (DFP)] were injected into the proximal half of the gastrocnemius muscle, and the muscle nerve was electrically stimulated for 30-60 min for induction of muscle twitches. The distal half of the muscle, which performed the same contractions, served as a control to assess the effects of the twitches without DFP. Sections of the muscle were evaluated for morphological changes in relation to the location of blocked end plates. Compared with the distal half of the muscle, the DFP-injected proximal half exhibited significantly higher numbers of abnormally contracted fibers (local contractures), torn fibers, and longitudinal stripes. DFP-injected animals in which the muscle nerve was not stimulated and that were allowed to survive for 24 h exhibited the same lesions but in smaller numbers. The data indicate that an increased concentration of ACh in a few end plates causes damage to muscle fibers. The results support the assumption that a dysfunctional end plate exhibiting increased release of ACh may be the starting point for regional abnormal contractions, which are thought to be essential for the formation of myofascial trigger points.

  15. HI-6 assisted catalytic scavenging of VX by acetylcholinesterase choline binding site mutants.

    Maček Hrvat, Nikolina; Žunec, Suzana; Taylor, Palmer; Radić, Zoran; Kovarik, Zrinka

    2016-11-25

    The high toxicity of organophosphorus compounds originates from covalent inhibition of acetylcholinesterase (AChE), an essential enzyme in cholinergic neurotransmission. Poisonings that lead to life-threatening toxic manifestations require immediate treatment that combines administration of anticholinergic drugs and an aldoxime as a reactivator of AChE. An alternative approach to reduce the in vivo toxicity of OPs focuses on the use of bioscavengers against the parent organophosphate. Our previous research showed that AChE mutagenesis can enable aldoximes to substantially accelerate the reactivation of OP-enzyme conjugates, while dramatically slowing down rates of OP-conjugate dealkylation (aging). Herein, we demonstrate an efficient HI-6-assisted VX detoxification, both ex vivo in human blood and in vivo in mice by hAChE mutants modified at the choline binding site (Y337A and Y337A/F338A). The catalytic scavenging of VX in mice improved therapeutic outcomes preventing lethality and resulted in a delayed onset of toxicity symptoms.

  16. A comparison of the potency of trimedoxime and other currently available oximes to reactivate tabun-inhibited acetylcholinesterase and eliminate acute toxic effects of tabun.

    Kassa, Jirí; Kuca, Kamil; Cabal, Jirí

    2005-12-01

    Tabun (O-ethyl-N,N-dimethyl phosphoramidocyanidate) belongs to highly toxic organophosphorus compounds misused as chemical warfare agents for military as well as terroristic purposes. It differs from other highly toxic organophosphates by its chemical structure and by the fact that tabun-inhibited acetylcholinesterase is extraordinarily difficult to reactivate. The potency of trimedoxime and other commonly used oximes (pralidoxime, obidoxime, the oxime HI-6) to reactivate tabun-inhibited acetylcholinesterase and to eliminate tabun-induced acute effects was evaluated using in vitro and in vivo methods. In vitro calculated kinetic parameters of reactivation of tabun-inhibited acetylcholinesterase from rat brain homogenate and in vivo determined percentage of reactivation of tabun-inhibited blood and tissue acetylcholinesterase in poisoned rats show that trimedoxime seems to be the most efficacious reactivator in the case of tabun poisonings. Trimedoxime was also found to be the most efficacious oxime in the elimination of acute lethal toxic effects in tabun-poisoned rats and mice. The oxime HI-6, so efficacious against soman, does not seem to be sufficiently effective oxime to reactivate tabun-inhibited acetylcholinesterase and to counteract acute lethal effects of tabun.

  17. Overexpression of acetylcholinesterase inhibited cell proliferation and promoted apoptosis in NRK cells

    Qi-huang JIN; Heng-yi HE; Yu-fang SHI; He LU; Xue-jun ZHANG

    2004-01-01

    AIM: To study the potential function of acetylcholinesterase (AChE) in apoptosis through overexpression of AChE in Normal Rat Kidney (NRK) cells. METHODS: AChE activity was detected by the method of Karnovsky and Roots. Activated caspase-3 was analyzed by Western blotting and immunofiurescence with antibody special to activated caspase-3 fragment. The expression plasmids were constructed in pcDNA3.1 containing AChE gene or a fragment of AChE antisense that were got from RT-PCR. Stable expression cell lines were selected by G418 in cells transfected by lipofection. AChE expression was analyzed by RT-PCR and Western blotting. The proliferation rates of transfected cells were examined by the growth curve and cloning efficiency. MTT assay was used to analyze the cell viability. RESULTS: The proliferation rate of the cells transfected with AChE was retarded and the cloning efficiency was lower (28.2 %±3.1% and 48.7 %±2.1%) than cells transfected with vector (56.1%±0.3 %) or AChE-antisense (77.7 %±2.2 %). After 2 d the various clone types were deprived of serum, the residue cell viability were 10.4 %±4.6 % and 12.6 %±6.7 % in the cells transfected with AChE, and 27.4 %±3.5 % in cells with vector, and 50.3 %±7.8 % in cells with AChE-antisense. CONCLUSION: During apoptosis, increase of AChE protein is to inhibit cell proliferation, and then to promote apoptosis in NRK cells.

  18. Acetylcholinesterase loosens the brain's cholinergic anti-inflammatory response and promotes epileptogenesis

    Yehudit eGnatek

    2012-05-01

    Full Text Available Recent studies show a key role of brain inflammation in epilepsy. However, the mechanisms controlling brain immune response are only partly understood. In the periphery, acetylcholine (ACh release by the vagus nerve restrains inflammation by inhibiting the activation of leukocytes. Recent reports suggested a similar anti-inflammatory effect for ACh in the brain. Since brain cholinergic dysfunction are documented in epileptic animals, we explored changes in brain cholinergic gene expression and associated immune response during pilocarpine-induced epileptogenesis. Levels of acetylcholinesterase (AChE and inflammatory markers were measured using real-time RT-PCR, in-situ hybridization and immunostaining in wild type (WT and transgenic mice over-expressing the "synaptic" splice variant AChE-S (TgS. One month following pilocarpine, mice were video-monitored for spontaneous seizures. To test directly the effect of ACh on the brain's innate immune response, cytokines expression levels were measured in acute brain slices treated with cholinergic agents. We report a robust upregulation of AChE as early as 48 hrs following pilocarpine-induced status epilepticus (SE. AChE was expressed in hippocampal neurons, microglia and endothelial cells but rarely in astrocytes. TgS mice overexpressing AChE showed constitutive increased microglial activation, elevated levels of pro-inflammatory cytokines 48 hrs after SE and accelerated epileptogenesis compared to their WT counterparts. Finally we show a direct, muscarine-receptor dependant, nicotine-receptor independent anti-inflammatory effect of ACh in brain slices maintained ex vivo. Our work demonstrates for the first time, that ACh directly suppresses brain innate immune response and that AChE up-regulation after SE is associated with enhanced immune response, facilitating the epileptogenic process. Our results highlight the cholinergic system as a potential new target for the prevention of seizures and epilepsy.

  19. Acetylcholinesterase Inhibitor Improves Learning and Memory Impairment Induced by Toxoplasma gondii Infection

    Hossein MAHMOUDVAND

    2016-10-01

    Full Text Available Background: Here, we established the mouse models of chronic toxoplasmosis by T. gondii Tehran strain to provide a good understanding about defining the possible association between T. gondii exposure and learning and memory impairments. Moreover, as secondary objective of the present study, we hypothesized whether administration of an acetylcholinesterase (AChE inhibitor could reduce learning and memory impairments induced by T. gondii infection.Methods: Twenty-four male BALB/c mice were used to establishment of latent toxoplasmosis. The animal model of Toxoplasma infection was established by the intraperitoneal inoculation of 20-25 tissue cysts from Tehran strain of T. gondii. Donepezil (2 mg/kg an AChE inhibitor to treat Alzheimer disease was injected intraperitoneally once a day for two weeks starting from post-infection day 90. Morris water maze (MWM task was used to assay spatial learning and short term spatial memory in all groups. One-way ANOVA with Tukey’s post-hoc test was used to assess differences between experimental groups.  P<0.05 was considered statistically significant.Results: Toxoplasma infection impaired spatial leaning and short term spatial memory of the infected BALB/c mice, whereas donepezil, an AChE inhibitor, improved impairments induced by Toxoplasma infection.Conclusion: T. gondii infection through increasing AChE reduces the level of Acetylcholine (Ach and consequently affects learning and memory activity in infected hosts, whereas, donepezil as an AChE inhibitor improves these impairments by restoring ACh levels at synapses of neurons in brain.

  20. Copper acutely impairs behavioral function and muscle acetylcholinesterase activity in zebrafish (Danio rerio).

    Haverroth, Gabriela M B; Welang, Chariane; Mocelin, Riciéri N; Postay, Daniela; Bertoncello, Kanandra T; Franscescon, Francini; Rosemberg, Denis B; Dal Magro, Jacir; Dalla Corte, Cristiane L

    2015-12-01

    Copper is a heavy metal found at relatively high concentrations in surface waters around the world. Copper is a micronutrient at low concentrations and is essential to several organisms. At higher concentrations copper can become toxic, which reveal the importance of studying the toxic effects of this metal on the aquatic life. Thus, the objective of this study was to evaluate the toxic effects of copper on the behavior and biochemical parameters of zebrafish (Danio rerio). Zebrafish were exposed for 24h at a concentration of 0.006 mg/L Cu. After the exposure period, behavioral profile of animals was recorded through 6 min using two different apparatuses tests: the Novel Tank and the Light-Dark test. After behavioral testing, animals were euthanized with a solution of 250 mg/L of tricaine (MS-222). Brain, muscle, liver and gills were extracted for analysis of parameters related to oxidative stress and accumulation of copper in these tissues. Acetylcholinesterase (AChE) activity was determined in brain and muscle. Results showed acute exposure to copper induces significant changes in behavioral profile of zebrafish by changing locomotion and natural tendency to avoid brightly lit area. On the other hand, there were no significant effects on parameters related to oxidative stress. AChE activity decreased significantly in zebrafish muscle, but there were no significant changes in cerebral AChE activity. Copper levels in tissues did not increase significantly compared to the controls. Taken together, these results indicate that a low concentration of copper can acutely affect behavioral profile of adult zebrafish which could be partially related to an inhibition on muscle AChE activity. These results reinforce the need of additional tests to establishment of safe copper concentrations to aquatic organisms and the importance of behavioral parameters in ecotoxicological studies.

  1. Effect of ions on the activity of brain acetylcholinesterase from tropical fish

    Caio Rodrigo Dias Assis

    2015-07-01

    Full Text Available Objective: To investigate the effect of ions on brain acetylcholinesterase (AChE; EC 3.1.1.7 activities from economic important fish [pirarucu, Arapaima gigas; tambaqui, Colossoma macropomum; cobia, Rachycentron canadum (R. canadum and Nile tilapia, Oreochromis niloticus (O. niloticus] comparing with a commercial enzyme from electric eel [Electrophorus electricus (E. electricus]. Methods: The in vitro exposure was performed at concentrations ranging from 0.001 to 10 mmol/L (except for ethylene diamine tetraacetic acid; up to 150 mmol/L. Inhibition kinetics on R. canadum and O. niloticus were also observed through four methods (Michaelis-Menten, Lineweaver-Burk, Dixon and Cornish-Bowden plots in order to investigate the type of inhibition produced by some ions. Results: Hg 2+ , As 3+ , Cu 2+ , Zn 2+ , Cd 2+ caused inhibition in all the species under study. Ca 2+ , Mg 2+ and Mn 2+ induced slight activation in R. canadum enzyme while Pb 2+ , Ba 2+ , Fe 2+ , Li + inhibited the AChE from some of the analyzed species. The lowest IC 50 and Ki values were estimated for E. electricus AChE in presence of Hg 2+ , Pb 2+ , Zn 2+ . Under our experimental conditions, the results for R. canadum and O. niloticus, As 3+ , Cu 2+ , Cd 2+ , Pb 2+ and Zn 2+ showed a non- competitive/mixed-type inhibition, while Hg 2+ inhibited the enzyme in a mixed/competitive- like manner. Conclusions: E. electricus AChE activity was affected by ten of fifteen ions under study showing that this enzyme could undergo interference by these ions when used as pesticide biosensor in environmental analysis. This hindrance would be less relevant for the crude extracts.

  2. Biochemical and toxicological properties of two acetylcholinesterases from the common bed bug, Cimex lectularius.

    Hwang, Chae Eun; Kim, Young Ho; Kwon, Deok Ho; Seong, Keon Mook; Choi, Jae Young; Je, Yeon Ho; Lee, Si Hyeock

    2014-03-01

    We examined the molecular and enzymatic properties of two acetylcholinesterases (AChEs; ClAChE1 and ClAChE2) from the common bed bug, Cimex lectularius. Native polyacrylamide gel electrophoresis followed by activity staining and Western blotting revealed that ClAChE1 is the main catalytic enzyme and is abundantly expressed in various tissues. Both ClAChEs existed in dimeric form connected by a disulfide bridge and were attached to the membrane via a glycophosphatidylinositol anchor. To determine their kinetic and inhibitory properties, both ClAChE1 and ClAChE2 were in vitro expressed in Sf9 cells using a baculovirus expression system. ClAChE1 showed higher catalytic efficiency toward acetylcholine, supporting the hypothesis that ClAChE1 plays a major role in postsynaptic transmission. An inhibition assay revealed that ClAChE1 is generally more sensitive to organophosphates and carbamates examined although ClAChE2 was >4000-fold more sensitive to malaoxon than ClAChE1. The relatively higher correlation between the in vitro ClAChE1 inhibition and the in vivo toxicity suggested that ClAChE1 is the more relevant toxicological target for organophosphates and carbamates. Although the physiological function of ClAChE2 remains to be elucidated, ClAChE2 also appears to have neuronal functions, as judged by its tissue distribution and molecular and kinetic properties. Our findings help expand our knowledge on insect AChEs and their toxicological properties.

  3. Acetylcholinesterase inhibition in the threeridge mussel (Amblema plicata) by chlorpyrifos: implications for biomonitoring

    Doran, W.J.; Cope, W.G.; Rada, R.G.; Sandheinrich, M.B.

    2001-01-01

    The effects of chlorpyrifos, an organophosphorus insecticide, were examined on the activity of the nervous system enzyme acetylcholinesterase (AChE) in the threeridge mussel Amblema plicata in a 24-day laboratory test. Thirty-six mussels in each of seven treatments (18 mussels per duplicate) were exposed to chlorpyrifos (0.1, 0.2, 0.3, 0.6, and 1.2 mg/L), a solvent (acetone), and a solvent-free (well water) control for 12, 24, or 96 h. The activity of AChE was measured in the anterior adductor muscle of eight mussels from each treatment after exposure. To assess potential latent effects, six mussels from each treatment were removed after 24 h of exposure and transferred to untreated water for a 21-day holding period; AChE activity was measured on three mussels from each treatment at 7 and 21 days of the holding period. The activity of AChE in chlorpyrifos-exposed mussels did not differ from controls after 12 or 24 h of exposure (t- test, P>0.05), but was significantly less than controls after 96 h (t- test, P=0.01). AChE activity did not vary among mussels at 24 h of exposure (i.e., Day 0 of holding period) and those at Day 7 and Day 21 of the holding period. Overall changes in AChE activity of mussels during the test were unrelated to individual chlorpyrifos concentrations and exposure times (repeated measure ANOVA; (P=0.06). A power analysis revealed that the sample size must be increased from 2 to 5 replicates (8 to 20 mussels per time interval and test concentration) to increase the probability of detecting significant differences in AChE activity. This calculated increase in sample size has potential implications for future biomonitoring studies with chlorpyrifos and unionid mussels.

  4. Targeting acetylcholinesterase: identification of chemical leads by high throughput screening, structure determination and molecular modeling.

    Lotta Berg

    Full Text Available Acetylcholinesterase (AChE is an essential enzyme that terminates cholinergic transmission by rapid hydrolysis of the neurotransmitter acetylcholine. Compounds inhibiting this enzyme can be used (inter alia to treat cholinergic deficiencies (e.g. in Alzheimer's disease, but may also act as dangerous toxins (e.g. nerve agents such as sarin. Treatment of nerve agent poisoning involves use of antidotes, small molecules capable of reactivating AChE. We have screened a collection of organic molecules to assess their ability to inhibit the enzymatic activity of AChE, aiming to find lead compounds for further optimization leading to drugs with increased efficacy and/or decreased side effects. 124 inhibitors were discovered, with considerable chemical diversity regarding size, polarity, flexibility and charge distribution. An extensive structure determination campaign resulted in a set of crystal structures of protein-ligand complexes. Overall, the ligands have substantial interactions with the peripheral anionic site of AChE, and the majority form additional interactions with the catalytic site (CAS. Reproduction of the bioactive conformation of six of the ligands using molecular docking simulations required modification of the default parameter settings of the docking software. The results show that docking-assisted structure-based design of AChE inhibitors is challenging and requires crystallographic support to obtain reliable results, at least with currently available software. The complex formed between C5685 and Mus musculus AChE (C5685•mAChE is a representative structure for the general binding mode of the determined structures. The CAS binding part of C5685 could not be structurally determined due to a disordered electron density map and the developed docking protocol was used to predict the binding modes of this part of the molecule. We believe that chemical modifications of our discovered inhibitors, biochemical and biophysical

  5. Scopolamine induces disruption of latent inhibition which is prevented by antipsychotic drugs and an acetylcholinesterase inhibitor.

    Barak, Segev; Weiner, Ina

    2007-05-01

    The fact that muscarinic antagonists may evoke a psychotic state ('antimuscarinic psychosis'), along with findings of cholinergic alterations in schizophrenia, have kindled an interest in the involvement of the cholinergic system in this disorder. Latent inhibition (LI) is a cross-species phenomenon manifested as a poorer conditioning of a stimulus seen when the stage of conditioning is preceded by a stage of repeated nonreinforced pre-exposure to that stimulus, and is considered to index the capacity to ignore irrelevant stimuli. Amphetamine-induced LI disruption and its reversal by antipsychotic drugs (APDs) is a well-established model of positive symptoms of schizophrenia. Here, we tested whether the muscarinic antagonist scopolamine would disrupt LI and whether such disruption would be reversed by APDs and by the acetylcholinesterase inhibitor physostigmine. The results showed that scopolamine at doses of 0.15 and 0.5 mg/kg disrupted LI, and that this effect was due to the action of the drug in the pre-exposure stage, suggesting a role of muscarinic transmission in attentional processes underlying LI. Both the typical and the atypical APDs, haloperidol and clozapine, reversed scopolamine-induced LI disruption when given in conditioning or in both stages, but not in pre-exposure, indicating that the mechanism of antipsychotic action in this model is independent of the mechanism of action of the propsychotic drug. Scopolamine-induced LI disruption was reversed by physostigmine (0.05 and 0.15 mg/kg), which was ineffective in reversing amphetamine-induced LI disruption, pointing to distinct mechanisms underlying LI disruption by these two propsychotic drugs. The latter was further supported by the finding that unlike amphetamine, the LI-disrupting doses of scopolamine did not affect activity levels. We propose scopolamine-induced LI disruption as a model of cholinergic-related positive symptoms in schizophrenia.

  6. Acetylcholinesterase Inhibitor Improves Learning and Memory Impairment Induced by Toxoplasma gondii Infection

    MAHMOUDVAND, Hossein; SHEIBANI, Vahid; KESHAVARZ, Hossein; SHOJAEE, Saeedeh; ESMAEELPOUR, Khadijeh; ZIAALI, Naser

    2016-01-01

    Background: Here, we established the mouse models of chronic toxoplasmosis by T. gondii Tehran strain to provide a good understanding about defining the possible association between T. gondii exposure and learning and memory impairments. Moreover, as secondary objective of the present study, we hypothesized whether administration of an acetylcholinesterase (AChE) inhibitor could reduce learning and memory impairments induced by T. gondii infection. Methods: Twenty-four male BALB/c mice were used to establishment of latent toxoplasmosis. The animal model of Toxoplasma infection was established by the intraperitoneal inoculation of 20–25 tissue cysts from Tehran strain of T. gondii. Donepezil (2 mg/kg) an AChE inhibitor to treat Alzheimer disease was injected intraperitoneally once a day for two weeks starting from post-infection day 90. Morris water maze (MWM) task was used to assay spatial learning and short term spatial memory in all groups. One-way ANOVA with Tukey’s post-hoc test was used to assess differences between experimental groups. P<0.05 was considered statistically significant. Results: Toxoplasma infection impaired spatial leaning and short term spatial memory of the infected BALB/c mice, whereas donepezil, an AChE inhibitor, improved impairments induced by Toxoplasma infection. Conclusion: T. gondii infection through increasing AChE reduces the level of Acetylcholine (Ach) and consequently affects learning and memory activity in infected hosts, whereas, donepezil as an AChE inhibitor improves these impairments by restoring ACh levels at synapses of neurons in brain. PMID:28096851

  7. Effects of acetylcholinesterase gene silencing on its activity in cultured human skeletal muscle.

    Mis, Katarina; Mars, Tomaz; Golicnik, Marko; Jevsek, Marko; Grubic, Zoran

    2006-01-01

    In spite of several reports demonstrating that acetylcholinesterase (AChE [EC 3.1.1.7]) expression is importantly regulated at the level of its mRNA, we still know little about the relationship between AChE mRNA level and the level of mature, catalytically active enzyme in the cell. Better insight into this relationship is, however, essential for our understanding of the molecular pathways underlying AChE synthesis in living cells. We have approached this problem previously (Grubic et al., 1995; Brank et al., 1998; Mis et al., 2003; Jevsek et al., 2004); however, recently introduced small interfering RNA (siRNA) methodology, which allows blockade of gene expression at the mRNA level, opens new possibilities in approaching the AChE mRNA-AChE activity relationship. With this technique one can eliminate AChE mRNA in the cell, specifically and at selected times, and follow the effects of such treatment at the mature enzyme level. In this study we followed AChE activity in siRNA-treated cultured human myoblasts. Our aim was to find out how the temporal profile of the AChE mRNA decrease is reflected at the level of AChE activity under normal conditions and after inhibition of preexisting AChE by diisopropyl phosphorofluoridate (DFP).AChE activity was determined at selected time intervals after siRNA treatment in both myoblast homogenates and in culture medium to follow the effects of siRNA treatment at the level of intracellular AChE synthesis and at the level of AChE secreted from the cell.

  8. Acetylcholinesterase (AChE inhibition aggravates fasting-induced triglyceride accumulation in the mouse liver

    Shin-Ichi Yokota

    2014-01-01

    Full Text Available Although fasting induces hepatic triglyceride (TG accumulation in both rodents and humans, little is known about the underlying mechanism. Because parasympathetic nervous system activity tends to attenuate the secretion of very-low-density-lipoprotein-triglyceride (VLDL-TG and increase TG stores in the liver, and serum cholinesterase activity is elevated in fatty liver disease, the inhibition of the parasympathetic neurotransmitter acetylcholinesterase (AChE may have some influence on hepatic lipid metabolism. To assess the influence of AChE inhibition on lipid metabolism, the effect of physostigmine, an AChE inhibitor, on fasting-induced increase in liver TG was investigated in mice. In comparison with ad libitum-fed mice, 30 h fasting increased liver TG accumulation accompanied by a downregulation of sterol regulatory element-binding protein 1 (SREBP-1 and liver-fatty acid binding-protein (L-FABP. Physostigmine promoted the 30 h fasting-induced increase in liver TG levels in a dose-dependent manner, accompanied by a significant fall in plasma insulin levels, without a fall in plasma TG. Furthermore, physostigmine significantly attenuated the fasting-induced decrease of both mRNA and protein levels of SREBP-1 and L-FABP, and increased IRS-2 protein levels in the liver. The muscarinic receptor antagonist atropine blocked these effects of physostigmine on liver TG, serum insulin, and hepatic protein levels of SREBP-1 and L-FABP. These results demonstrate that AChE inhibition facilitated fasting-induced TG accumulation with up regulation of the hepatic L-FABP and SREBP-1 in mice, at least in part via the activation of muscarinic acetylcholine receptors. Our studies highlight the crucial role of parasympathetic regulation in fasting-induced TG accumulation, and may be an important source of information on the mechanism of hepatic disorders of lipid metabolism.

  9. Effect of ions on the activity of brain acetylcholinesterase from tropical ifsh

    Caio Rodrigo Dias Assis; Amanda Guedes Linhares; Vagne Melo Oliveira; Renata Cristina Penha Frana; Juliana Ferreira Santos; Ranilson Souza Bezerra; Luiz Bezerra Carvalho Jr

    2015-01-01

    Objective:To investigate the effect of ions on brain acetylcholinesterase (AChE; EC 3.1.1.7) activities from economic important fish [pirarucu,Arapaima gigas; tambaqui,Colossoma macropomum; cobia,Rachycentron canadum (R. canadum) and Nile tilapia,Oreochromis niloticus(O. niloticus)] comparing with a commercial enzyme from electric eel [Electrophorus electricus(E. electricus)]. Methods: Thein vitro exposure was performed at concentrations ranging from 0.001 to 10 mmol/L (except for ethylene diamine tetraacetic acid; up to 150 mmol/L). Inhibition kinetics onR. canadum andO. niloticus were also observed through four methods (Michaelis-Menten, Lineweaver-Burk, Dixon and Cornish-Bowden plots) in order to investigate the type of inhibition produced by some ions. Results: Hg2+, As3+, Cu2+, Zn2+, Cd2+ caused inhibition in all the species under study. Ca2+, Mg2+ and Mn2+ induced slight activation inR. canadum enzyme while Pb2+, Ba2+, Fe2+, Li+ inhibited the AChE from some of the analyzed species. The lowest IC50 and Ki values were estimated forE. electricus AChE in presence of Hg2+, Pb2+, Zn2+. Under our experimental conditions, the results forR. canadum andO. niloticus, As3+, Cu2+, Cd2+, Pb2+ and Zn2+ showed a non-competitive/mixed-type inhibition, while Hg2+ inhibited the enzyme in a mixed/competitive-like manner. Conclusions:E. electricus AChE activity was affected by ten of fifteen ions under study showing that this enzyme could undergo interference by these ions when used as pesticide biosensor in environmental analysis. This hindrance would be less relevant for the crude extracts.

  10. Anti-epitope antibody,a novel site-directed antibody against human acetylcholinesterase

    Xing-mei ZHANG; Gang LIU; Man-ji SUN

    2004-01-01

    AIM: To construct synthetic antigens using the epitope of human brain acetylcholinesterase (hbAChE) for induction and detection of the specific antibody against the epitope, and to analyse the immunogenicity of the antibody.METHODS: The epitope (RTVLVSMNYR, amino acids 143-152) of hbAChE was chemically synthesized, coupled with the carrier protein keyhole limpet hemocyanin (KLH) to construct an artificial immunogen (KLH-epitope), and injected into rabbits to raise antibody. The epitope conjugated with bovine serum albumin (BSA) was used as the detection antigen. The specificity of the antibody was tested by enzyme-linked immunosorbent assay (ELISA) and Western blotting. The immunoreaction between the anti-recombinant human butyrylcholinesterase (rhBChE)polyclonal antibody and the biotinylated-epitope was examined by indirect ELISA. RESULTS: The erythrocyte AChE, the hbAChE, rhBChE and the BSA-epitope all immunoreacted with the anti-epitope antibody against the epitope (143-152) of hbAChE, whereas the torpedo AChE did not. CONCLUSION: The hbAChE, the human erythrocyte AChE and hBChE share the conservative antigenic epitope RTVLVSMNYR, hence they can all immunoreact with the anti-epitope antibody. Since the epitope of hbAChE is less similar with the aligned amino acid sequences of AChE of Torpedo californica or Torpedo marmorata, there is not any immunoreactivity between them. The R, M, and N residues in the epitope seem to be necessary radicals for the conservation of antigenicity.

  11. Molecular characterization of monoclonal antibodies that inhibit acetylcholinesterase by targeting the peripheral site and backdoor region.

    Yves Bourne

    Full Text Available The inhibition properties and target sites of monoclonal antibodies (mAbs Elec403, Elec408 and Elec410, generated against Electrophorus electricus acetylcholinesterase (AChE, have been defined previously using biochemical and mutagenesis approaches. Elec403 and Elec410, which bind competitively with each other and with the peptidic toxin inhibitor fasciculin, are directed toward distinctive albeit overlapping epitopes located at the AChE peripheral anionic site, which surrounds the entrance of the active site gorge. Elec408, which is not competitive with the other two mAbs nor fasciculin, targets a second epitope located in the backdoor region, distant from the gorge entrance. To characterize the molecular determinants dictating their binding site specificity, we cloned and sequenced the mAbs; generated antigen-binding fragments (Fab retaining the parental inhibition properties; and explored their structure-function relationships using complementary x-ray crystallography, homology modeling and flexible docking approaches. Hypermutation of one Elec403 complementarity-determining region suggests occurrence of antigen-driven selection towards recognition of the AChE peripheral site. Comparative analysis of the 1.9Å-resolution structure of Fab408 and of theoretical models of its Fab403 and Fab410 congeners evidences distinctive surface topographies and anisotropic repartitions of charges, consistent with their respective target sites and inhibition properties. Finally, a validated, data-driven docking model of the Fab403-AChE complex suggests a mode of binding at the PAS that fully correlates with the functional data. This comprehensive study documents the molecular peculiarities of Fab403 and Fab410, as the largest peptidic inhibitors directed towards the peripheral site, and those of Fab408, as the first inhibitor directed toward the backdoor region of an AChE and a unique template for the design of new, specific modulators of AChE catalysis.

  12. Bioassay- and liquid chromatography/mass spectrometry-guided acetylcholinesterase inhibitors from Picriafel-terrae

    Lu Wen

    2013-01-01

    Full Text Available Background: Picria fel-terrae is a traditional Chinese medicine. Materials and Methods: A new approach to the search for acetylcholinesterase (AChE inhibitors from Picria fel-terrae is presented. Results: Bioassay- and LC-MS-guided fractionation of the ethyl acetate extract was from traditional Chinese medicine P.fel-terrae. Following primary extraction, the ethyl acetate extracts fraction of P.fel-terrae showed strong AChE inhibitory activities. So the sample was separated using highperformance liquid chromatography (HPLC. The effluent was split towards two identical 96-well fraction collectors, and the presence of the biologically interesting portion and chromatographic fractions could be readily detected by analyzing selected ion chromatograms through an electrophoresis-electrospray ionization mass spectrometry (ESIMS system for accurate mass measurement. One 96-well plate was used for a bioassay (AChE-inhibitory assay and detected the bioactivity and position of the relevant peak in the chromatogram. The positive well in the second 96-well plate was used for identification by LC-(+ ESIMS. Conclusion: As abovementioned, the AChE inhibitory constituents from P.fel-terrae by LC-bioassay-ESIMS were rapid identified. Liquid chromatography/ mass spectrometry (LC-MS screening detected the presence of six active compounds, identified as picfeltarraenin IA (1, picfeltarraenin IB (2, picfeltarraenin IV (3, picfeltarraenin X (4, picfeltarraenin XI (5, and one unknown compound. The structures were further determined by 13C NMR. The six compounds expressed stronger AChE inhibition than the known AChE inhibitorTacrine. Above all, the value of this LC-bioassay-ESIMS methodology is highlighted by the finding and structure elucidation of the active constituents from many other structural families of natural products.

  13. Isolation and characterisation of acetylcholinesterase inhibitors from Aquilaria subintegra for the treatment of Alzheimer's disease (AD).

    Bahrani, Hirbod; Mohamad, Jamaludin; Paydar, Mohammad Javad; Rothan, Hussin A

    2014-02-01

    Aquilaria subintegra, locally known as "Gaharu", belongs to the Thymelaeceae family. This plant's leaves have been claimed to be effective for the treatment of Alzheimer's disease (AD) by Malay traditional practitioner in Malaysia. In this research, the chloroform extracts of the leaves and stem of A. subintegra were tested for acetylcholinesterase (AChE) inhibitory activity. The Thin Layer Chromatography (TLC) results indicated the presence of phenols, flavonoids, terpenoids, and alkaloids compounds in the extracts. Analysis of the stem chloroform extracts with LCMS/MS displayed that it contains kaempferol 3,4,7-trimethyl ether. The AChE inhibitory activity of leaves and stem chloroform extracts and kaempferol were 80%, 93% and 85.8%, respectively. The Brine Shrimp Lethality Assay (BSLA) exhibited low to moderate toxicity of the chloroform extract from leaves (LC50=531.18 ± 49.53 μg/ml), the stem chloroform extract (LC50=407.34 ± 68.05 μg/ml) and kaempferol (LC50=762.41 ± 45.09 μg/ml). The extracts and kaempferol were not cytotoxic to human umbilical vein endothelial cells (HUVEC), human normal gastric epithelial cell line (GES-1) and human normal hepatic cell line (WRL-68). The effect of leaf and stem chloroform extracts and kaempferol were determined in the Radial Arm Maze (RAM) after administration by oral gavage to ICR male and female mice with valium-impaired memory. Administration of kaempferol to the mice significantly reduced the number of repeated entries into the arms of maze in males and females. In conclusion, the inhibition of AChE by leaf and stem chloroform extracts of A. subintegra could be due to the presence of kaempferol. This extract is safe for use as a natural AChE inhibitor as an alternative to berberine for the treatment of AD.

  14. Chromatographic preparation and kinetic analysis of interactions between tabun enantiomers and acetylcholinesterase.

    Tenberken, O; Thiermann, H; Worek, F; Reiter, G

    2010-06-02

    The easy accessibility to highly toxic OP (organophosphorus)-type chemical warfare agents (nerve agents) underlines the necessity for an effective medical treatment. Acute OP toxicity is primarily caused by inhibition of acetylcholinesterase (AChE, EC 3.1.1.7). Reactivators (oximes) of inhibited AChE are a mainstay of treatment. However, the commercially available compounds, obidoxime and pralidoxime, are considered rather ineffective against various nerve agents, including tabun. OP-type chemical warfare agents include an asymmetrical P-atom and consist of at least two stereoisomers. Previous studies with the nerve agents sarin and soman showed marked differences between (-)- and (+)-P isomers regarding AChE inhibition and stability in biological matrices. Hence, stereoselectivity is a key parameter for the development of optimized treatment. In the present study, the tabun enantiomers were isolated by semi-preparative liquid-chromatography (LC) with offline analysis by GC-PCI-MS and final characterization of optical purity (99.98% (-)-tabun and 99.83% (+)-tabun) and specific optical rotation. The inhibition and reactivation kinetics of the tabun enantiomers were determined with human and swine AChE and the aging kinetics with human AChE. The results show a large difference in the inhibitory potency between (-)- and (+)-tabun. The determination of reactivation and aging kinetics indicates that both reactions are at least in part determined by the residual (-)-tabun contamination (0.17%) of the (+)-tabun preparation. These data provide further insight into the kinetic interactions between tabun enantiomers and AChE and may contribute to the development of more effective treatment options.

  15. Fixation of the two Tabun isomers in acetylcholinesterase: a QM/MM study.

    Kwasnieski, Ophélie; Verdier, Laurent; Malacria, Max; Derat, Etienne

    2009-07-23

    Dysfunction of acetylcholinesterase (AChE) due to inhibition by organophosphorus (OP) compounds is a major threat since AChE is a key enzyme in neurotransmission. To more rigorously design reactivation agents, it is of prime importance to understand the mechanism of inhibition of AChE by OP compounds. Tabun is one of the more potent nerve agents. It is produced as a mixture of two enantiomers, one of them (the levorotatory isomer) being 6.3 times more potent. Could it be that the inhibition mechanism is different for the two enantiomers? To address this critical issue, we used a hybrid quantum mechanics/molecular mechanics (QM/MM) methodology. Calculations were performed using BP86 functional and TZVP basis set. Single points were also done with B3LYP and PBE0 functionals. We studied the four possible attacks of tabun on the oxygen of Ser203 using two crystallographic structures (PDB codes 2C0P and 3DL7): (S) tabun with the cyano group syn to the oxygen of Ser203 and (R) tabun with the cyano group anti, corresponding to the experimental X-ray structure; (S) tabun with the cyano group anti to the oxygen of Ser203 and (R) tabun with the cyano group syn, leading to a different isomer than was experimentally seen. We found that the most active enantiomer is (S) tabun with the cyano group syn to the oxygen of Ser203. Thus it seems that the cyano group does not leave anti to the oxygen of Ser203 due to repulsive polar interactions between cyanide and aromatic residues in the active site.

  16. The effect of aspartame metabolites on human erythrocyte membrane acetylcholinesterase activity.

    Tsakiris, Stylianos; Giannoulia-Karantana, Aglaia; Simintzi, Irene; Schulpis, Kleopatra H

    2006-01-01

    Studies have implicated aspartame (ASP) with neurological problems. The aim of this study was to evaluate acetylcholinesterase (AChE) activity in human erythrocyte membranes after incubation with the sum of ASP metabolites, phenylalanine (Phe), methanol (met) and aspartic acid (aspt), or with each one separately. Erythrocyte membranes were obtained from 12 healthy individuals and were incubated with ASP hydrolysis products for 1 h at 37 degrees C. AChE was measured spectrophotometrically. Incubation of membranes with ASP metabolites corresponding with 34 mg/kg, 150 mg/kg or 200 mg/kg of ASP consumption resulted in an enzyme activity reduction by -33%, -41%, and -57%, respectively. Met concentrations 0.14 mM, 0.60 mM, and 0.80 mM decreased the enzyme activity by -20%, -32% or -40%, respectively. Aspt concentrations 2.80 mM, 7.60 mM or 10.0 mM inhibited membrane AChE activity by -20%, -35%, and -47%, respectively. Phe concentrations 0.14 mM, 0.35 mM or 0.50mM reduced the enzyme activity by -11%, -33%, and -35%, respectively. Aspt or Phe concentrations 0.82 mM or 0.07 mM, respectively, did not alter the membrane AChE activity. It is concluded that low concentrations of ASP metabolites had no effect on the membrane enzyme activity, whereas high or toxic concentrations partially or remarkably decreased the membrane AChE activity, respectively. Additionally, neurological symptoms, including learning and memory processes, may be related to the high or toxic concentrations of the sweetener metabolites.

  17. Glyphosate Adversely Affects Danio rerio Males: Acetylcholinesterase Modulation and Oxidative Stress.

    Lopes, Fernanda Moreira; Caldas, Sergiane Souza; Primel, Ednei Gilberto; da Rosa, Carlos Eduardo

    2016-12-01

    It has been demonstrated that glyphosate-based herbicides are toxic to animals. In the present study, reactive oxygen species (ROS) generation, antioxidant capacity against peroxyl radicals (ACAP), and lipid peroxidation (LPO), as well as the activity and expression of the acetylcholinesterase (AChE) enzyme, were evaluated in Danio rerio males exposed to 5 or 10 mg/L of glyphosate for 24 and 96 h. An increase in ACAP in gills after 24 h was observed in the animals exposed to 5 mg/L of glyphosate. A decrease in LPO was observed in brain tissue of animals exposed to 10 mg/L after 24 h, while an increase was observed in muscle after 96 h. No significant alterations were observed in ROS generation. AChE activity was not altered in muscles or brains of animals exposed to either glyphosate concentration for 24 or 96 h. However, gene expression of this enzyme in the brain was reduced after 24 h and was enhanced in both brain and muscle tissues after 96 h. Thus, contrary to previous findings that had attributed the imbalance in the oxidative state of animals exposed to glyphosate-based herbicides to surfactants and other inert compounds, the present study demonstrated that glyphosate per se promotes this same effect in zebrafish males. Although glyphosate concentrations did not alter AChE activity, this study demonstrated for the first time that this molecule affects ache expression in male zebrafish D. rerio.

  18. Magnetic Electrochemical Immunoassays with Quantum Dot Labels for Detection of Phosphorylated Acetylcholinesterase in Plasma

    Wang, Hua; Wang, Jun; Timchalk, Charles; Lin, Yuehe

    2008-11-01

    A new magnetic electrochemical immunoassay has been developed as a tool for biomonitoring exposures to organophosphate (OP) compounds, e.g., insecticides and chemical nerve agents, by directly detecting organophosphorylated acetylcholinesterase (OP-AChE). This immunoassay uniquely incorporates highly efficient magnetic separation with ultrasensitive square wave voltammetry (SWV) analysis with quantum dots (QDs) as labels. A pair of antibodies was used to achieve the specific recognition of OP-AChE that was prepared with paraoxon as an OP model agent. Antiphosphoserine polyclonal antibodies were anchored on amorphous magnetic particles preferably chosen to capture OP-AChE from the sample matrixes by binding their phosphoserine moieties that were exposed through unfolding the protein adducts. This was validated by electrochemical examinations and enzyme-linked immunosorbent assays. Furthermore, antihuman AChE monoclonal antibodies were labeled with cadmium-source QDs to selectively recognize the captured OP-AChE, as characterized by transmission electron microscopy. The subsequent electrochemical SWV analysis of the cadmium component released by acid from the coupled QDs was conducted on disposable screen-printed electrodes. Experimental results indicated that the SWV-based immunoassays could yield a linear response over a broad concentration range of 0.3-300 ng/mL OP-AChE in human plasma with a detection limit of 0.15 ng/mL. Such a novel electrochemical immunoassay holds great promise as a simple, selective, sensitive, and field-deployable tool for the effective biomonitoring and diagnosis of potential exposures to nerve agents and pesticides.

  19. Comparison of oxime reactivation and aging of nerve agent-inhibited monkey and human acetylcholinesterases.

    Luo, Chunyuan; Tong, Min; Maxwell, Donald M; Saxena, Ashima

    2008-09-25

    Non-human primates are valuable animal models that are used for the evaluation of nerve agent toxicity as well as antidotes and results from animal experiments are extrapolated to humans. It has been demonstrated that the efficacy of an oxime primarily depends on its ability to reactivate nerve agent-inhibited acetylcholinesterase (AChE). If the in vitro oxime reactivation of nerve agent-inhibited animal AChE is similar to that of human AChE, it is likely that the results of an in vivo animal study will reliably extrapolate to humans. Therefore, the goal of this study was to compare the aging and reactivation of human and different monkey (Rhesus, Cynomolgus, and African Green) AChEs inhibited by GF, GD, and VR. The oximes examined include the traditional oxime 2-PAM, two H-oximes HI-6 and HLo-7, and the new candidate oxime MMB4. Results indicate that oxime reactivation of all three monkey AChEs was very similar to human AChE. The maximum difference in the second-order reactivation rate constant between human and three monkey AChEs or between AChEs from different monkey species was 5-fold. Aging rate constants of GF-, GD-, and VR-inhibited monkey AChEs were very similar to human AChE except for GF-inhibited monkey AChEs, which aged 2-3 times faster than the human enzyme. The results of this study suggest that all three monkey species are suitable animal models for nerve agent antidote evaluation since monkey AChEs possess similar biochemical/pharmacological properties to human AChE.

  20. Complete blood count and acetylcholinesterase activity of lymphocytes of demyelinated and ovariectomized rats treated with resveratrol.

    Martins, Danieli B; Mazzanti, Cinthia M; Costa, Márcio M; França, Raqueli; Pagnoncelli, Marcielen; Maciel, Roberto M; Schmatz, Roberta; Oliveira, Lizielle; Morsch, Vera; Facco, Grasiela; Visentini, Diandra; Mann, Thais; Mazzanti, Alexandre; Lopes, Sonia T A

    2012-12-01

    Resveratrol is a phytoestrogen that has many beneficial actions. This study aimed to evaluate the effect of resveratrol on the complete blood count (CBC) and the acetylcholinesterase (AChE) activity of lymphocytes of ovariectomized rats experimentally demyelinated by ethidium bromide (EB). Forty adult female Wistar rats (60 days, 200-220 g) were divided randomly into five groups (n = 4) to evaluate the demyelination phase and five groups (n = 4) to evaluate the remyelination phase. In each phase, the groups consisted of sham rats-G1; ovariectomized rats, not demyelinated, treated only with vehicle (ethanol 25%)-G2; demyelinated ovariectomized rats treated only with vehicle-G3; ovariectomized rats, not demyelinated, treated with resveratrol-G4; and demyelinated ovariectomized rats treated with resveratrol-G5. Only during the remyelination phase, CBC showed a significant difference (p < 0.05) in the number of monocytes between G2 and G5 groups. In the demyelination phase, there was a significant decrease (p < 0.05) in the AChE activity in the G4 group, while the G5 group was statistically similar to the G1, G2 and G4 groups. In the remyelination phase, there were no significant differences in the AChE activity among the groups. The treatment for 7 days with resveratrol with or without the experimental demyelization with EB appears to influence the AChE activity of lymphocytes, without changing the number of these cells in the circulation. However, in the remyelination phase, there seems to be stabilization in its effect on the lymphocyte AChE activity.

  1. Donepezil, an acetylcholinesterase inhibitor against Alzheimer's dementia, promotes angiogenesis in an ischemic hindlimb model.

    Kakinuma, Yoshihiko; Furihata, Mutsuo; Akiyama, Tsuyoshi; Arikawa, Mikihiko; Handa, Takemi; Katare, Rajesh G; Sato, Takayuki

    2010-04-01

    Our recent studies have indicated that acetylcholine (ACh) protects cardiomyocytes from prolonged hypoxia through activation of the PI3K/Akt/HIF-1alpha/VEGF pathway and that cardiomyocyte-derived VEGF promotes angiogenesis in a paracrine fashion. These results suggest that a cholinergic system plays a role in modulating angiogenesis. Therefore, we assessed the hypothesis that the cholinergic modulator donepezil, an acetylcholinesterase inhibitor utilized in Alzheimer's disease, exhibits beneficial effects, especially on the acceleration of angiogenesis. We evaluated the effects of donepezil on angiogenic properties in vitro and in vivo, using an ischemic hindlimb model of alpha7 nicotinic receptor-deleted mice (alpha7 KO) and wild-type mice (WT). Donepezil activated angiogenic signals, i.e., HIF-1alpha and VEGF expression, and accelerated tube formation in human umbilical vein endothelial cells (HUVECs). ACh and nicotine upregulated signal transduction with acceleration of tube formation, suggesting that donepezil promotes a common angiogenesis pathway. Moreover, donepezil-treated WT exhibited rich capillaries with enhanced VEGF and PCNA endothelial expression, recovery from impaired tissue perfusion, prevention of ischemia-induced muscular atrophy with sustained surface skin temperature in the limb, and inhibition of apoptosis independent of the alpha7 receptor. Donepezil exerted comparably more effects in alpha7 KO in terms of angiogenesis, tissue perfusion, biochemical markers, and surface skin temperature. Donepezil concomitantly elevated VEGF expression in intracardiac endothelial cells of WT and alpha7 KO and further increased choline acetyltransferase (ChAT) protein expression, which is critical for ACh synthesis in endothelial cells. The present study concludes that donepezil can act as a therapeutic tool to accelerate angiogenesis in cardiovascular disease patients.

  2. Acetylcholinesterase Regulates Skeletal In Ovo Development of Chicken Limbs by ACh-Dependent and -Independent Mechanisms

    Spieker, Janine; Ackermann, Anica; Salfelder, Anika; Vogel-Höpker, Astrid; Layer, Paul G.

    2016-01-01

    Formation of the vertebrate limb presents an excellent model to analyze a non-neuronal cholinergic system (NNCS). Here, we first analyzed the expression of acetylcholinesterase (AChE) by IHC and of choline acetyltransferase (ChAT) by ISH in developing embryonic chicken limbs (stages HH17-37). AChE outlined formation of bones, being strongest at their distal tips, and later also marked areas of cell death. At onset, AChE and ChAT were elevated in two organizing centers of the limb anlage, the apical ectodermal ridge (AER) and zone of polarizing activity (ZPA), respectively. Thereby ChAT was expressed shortly after AChE, thus strongly supporting a leading role of AChE in limb formation. Then, we conducted loss-of-function studies via unilateral implantation of beads into chicken limb anlagen, which were soaked in cholinergic components. After varying periods, the formation of cartilage matrix and of mineralizing bones was followed by Alcian blue (AB) and Alizarin red (AR) stainings, respectively. Both acetylcholine (ACh)- and ChAT-soaked beads accelerated bone formation in ovo. Notably, inhibition of AChE by BW284c51, or by the monoclonal antibody MAB304 delayed cartilage formation. Since bead inhibition of BChE was mostly ineffective, an ACh-independent action during BW284c51 and MAB304 inhibition was indicated, which possibly could be due to an enzymatic side activity of AChE. In conclusion, skeletogenesis in chick is regulated by an ACh-dependent cholinergic system, but to some extent also by an ACh-independent aspect of the AChE protein. PMID:27574787

  3. Evidence for nonacetylcholinesterase targets of organophosphorus nerve agent: supersensitivity of acetylcholinesterase knockout mouse to VX lethality.

    Duysen, E G; Li, B; Xie, W; Schopfer, L M; Anderson, R S; Broomfield, C A; Lockridge, O

    2001-11-01

    The possibility that organophosphate toxicity is due to inhibition of targets other than acetylcholinesterase (AChE, EC 3.1.1.7) was examined in AChE knockout mice. Mice (34-55 days old) were grouped for this study, after it was determined that AChE, butyrylcholinesterase (BChE), and carboxylesterase activities had reached stable values by this age. Mice with 0, 50, or 100% AChE activity were treated subcutaneously with the nerve agent VX. The LD50 for VX was 10 to 12 microg/kg in AChE-/-, 17 microg/kg in AChE+/-, and 24 microg/kg in AChE+/+ mice. The same cholinergic signs of toxicity were present in AChE-/- mice as in wild-type mice, even though AChE-/- mice have no AChE whose inhibition could lead to cholinergic signs. Wild-type mice, but not AChE-/- mice, were protected by pretreatment with atropine. Tissues were extracted from VX-treated and untreated animals and tested for AChE, BChE, and acylpeptide hydrolase activity. VX treatment inhibited 50% of the AChE activity in brain and muscle of AChE+/+ and +/- mice, 50% of the BChE activity in all three AChE genotypes, but did not significantly inhibit acylpeptide hydrolase activity. It was concluded that the toxicity of VX must be attributed to inhibition of nonacetylcholinesterase targets in the AChE-/- mouse. Organophosphorus ester toxicity in wild-type mice is probably due to inhibition or binding to several proteins, only one of which is AChE.

  4. Acetylcholinesterase and butyrylcholinesterase inhibitory activity of some selected Nigerian medicinal plants

    Taiwo O. Elufioye

    2010-09-01

    Full Text Available Plants have been found to be useful as memory enhansers as well as antiaging. Twenty two of such plants from sixteen families were investigated for their acetylcholinesterase (AChE and butyrylcholinesterase (BuChE inhibitory activities using the in vitro Ellman's spectrophotometric and in situ bioautographic methods with physostigmine as standard. At least three morphological parts were examined for each of the plants investigated and the test concentration was 42.5 µg/ mL. Some plants were active on both enzymes though with some morphological parts being more active than others. The root bark of Spondias mombin showed the highest activity to the two enzymes; 64.77% and 83.94% on AChE and BuChE respectively. Other plant parts of the selected plants exhibited some remarkable selectivity in their actions. Those selectively active against AChE were Alchornia laxiflora stem bark (41.12% and root bark, Callophyllum inophyllurn root bark (56.52%. The leaves of C. jagus (74.25%, Morinda lucida leaves (40.15%, Peltophorum pterocarpum leaves and stem bark (49.5% and 68.85%, respectively, physiostigmine gave 90.31% inhibition. Generally higher activities were found against BuChE. Bombax bromoposenze leaves, root bark and stem bark were particularly active. The inhibition was over 80%. Other selective plant parts are the leaves Antiaris africana, Cissampelos owarensis aerial parts (78.96%, Combretum molle leaves and stem bark (90.42% and 88.13%, respectively, Dioscorea dumentorum root bark and tuber (over 87%, G. kola leaves, Markhamia tomentosa root bark, Pycnanthus angolensis stem bark and Tetrapleura tetraptera leaves. Most of these plants are taken as food or are food ingredients in Nigeria and may account for the low incidence of Alzheimer's disease in the country and may play certain roles in the mediation of the disease.

  5. 3,4-Methylenedioxymethamphetamine (MDMA) Abuse Markedly Inhibits Acetylcholinesterase Activity and Induces Severe Oxidative Damage and Liperoxidative Damage

    2003-01-01

    Objective To investigate whether 3,4-methylenedioxymethamphetamine (MDMA) abuse produces another neurotoxicity which may significantly inhibit the acetylcholinesterase activity and result in severe oxidative damage and liperoxidative damage to MDMA abusers. Methods 120 MDMA abusers (MA) and 120 healthy volunteers (HV) were enrolled in an independent sample control design, in which the levels of lipoperoxide (LPO) in plasma and erythrocytes as well as the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and acetylcholinesterase (AChE) in erythrocytes were determined by spectrophotometric methods. Results Compared with the average values of biochemical parameters in the HV group, those of LPO in plasma and erythrocytes in the MA group were significantly increased (P<0.0001), while those of SOD, CAT, GPX and AChE in erythrocytes in the MA group were significantly decreased (P<0.0001). The Pearson product-moment correlation analysis between the values of AChE and biochemical parameters in 120 MDMA abusers showed that significant linear negative correlation was present between the activity of AChE and the levels of LPO in plasma and erythrocytes (P<0.0005-0.0001), while significant linear positive correlation was observed between the activity of AchE and the activities of SOD, CAT and GPX (P<0.0001). The reliability analysis for the above biochemical parameters reflecting oxidative and lipoperoxidative damages in MDMA abusers suggested that the reliability coefficient (alpha) was 0.8124, and that the standardized item alpha was 0.9453. Conclusion The findings in the present study suggest that MDMA abuse can induce another neurotoxicity that significantly inhibits acetylcholinesterase activity and aggravates a series of free radical chain reactions and oxidative stress in the bodies of MDMA abusers, thereby resulting in severe neural, oxidative and lipoperoxidative damages in MDMA abusers.

  6. A comparison of reactivating and therapeutic efficacy of bispyridinium acetylcholinesterase reactivator KR-22934 with the oxime K203 and commonly used oximes (obidoxime, trimedoxime, HI-6) in tabun-poisoned rats and mice.

    Kassa, Jiri; Karasova, Jana Zdarova; Pavlikova, Ruzena; Musilek, Kamil; Kuca, Kamil; Bajgar, Jiri; Jung, Young-Sik

    2011-03-01

    The potency of bispyridinium acetylcholinesterase reactivator KR-22934 in reactivating tabun-inhibited acetylcholinesterase and reducing tabun-induced lethal toxic effects was compared with the oxime K203 and commonly used oximes. Studies determining percentage of reactivation of tabun-inhibited blood and tissue acetylcholinesterase in rats showed that the reactivating efficacy of KR-22934 was slightly higher than the reactivating efficacy of K203 and roughly corresponded to the reactivating efficacy of obidoxime and trimedoxime in blood and diaphragm. On the other hand, the oxime KR-22934 was not able to reactivate tabun-inhibited acetylcholinesterase in the brain. The therapeutic efficacy of all oximes studied approximately corresponded to their reactivating efficacy. Based on the results, one can conclude that the oxime KR-22934 is not suitable for the replacement of commonly used oximes for the antidotal treatment of tabun poisoning in spite of its potency to reactivate tabun-inhibited acetylcholinesterase in the peripheral compartment (blood, diaphragm).

  7. Effects of harmine, an acetylcholinesterase inhibitor, on spatial learning and memory of APP/PS1 transgenic mice and scopolamine-induced memory impairment mice.

    He, Dandan; Wu, Hui; Wei, Yue; Liu, Wei; Huang, Fei; Shi, Hailian; Zhang, Beibei; Wu, Xiaojun; Wang, Changhong

    2015-12-01

    Harmine, a β-carboline alkaloid present in Peganum harmala with a wide spectrum of pharmacological activities, has been shown to exert strong inhibition against acetylcholinesterase in vitro. However, whether it can rescue the impaired cognition has not been elucidated yet. In current study, we examined its effects on scopolamine-induced memory impairment mice and APP/PS1 transgenic mice, one of the models for Alzheimer's disease, using Morris Water Maze test. In addition, whether harmine could penetrate blood brain barrier, interact with and inhibit acetylcholinesterase, and activate downstream signaling network was also investigated. Our results showed that harmine (20mg/kg) administered by oral gavage for 2 weeks could effectively enhance the spatial cognition of C57BL/6 mice impaired by intraperitoneal injection of scopolamine (1mg/kg). Meanwhile, long-term consumption of harmine (20mg/kg) for 10 weeks also slightly benefited the impaired memory of APP/PS1 mice. Furthermore, harmine could pass through blood brain barrier, penetrate into the brain parenchyma shortly after oral administration, and modulate the expression of Egr-1, c-Jun and c-Fos. Molecular docking assay disclosed that harmine molecule could directly dock into the catalytic active site of acetylcholinesterase, which was partially confirmed by its in vivo inhibitory activity on acetylcholinesterase. Taken together, all these results suggested that harmine could ameliorate impaired memory by enhancement of cholinergic neurotransmission via inhibiting the activity of acetylcholinesterase, which may contribute to its clinical use in the therapy of neurological diseases characterized with acetylcholinesterase deficiency.

  8. Effect of thermal stress and water deprivation on the acetylcholinesterase activity of the pig brain and hypophyses

    Adejumo, D. O.; Egbunike, G. N.

    1988-06-01

    The effects of direct exposure of boars to thermal stress for 1 h daily for 5 days and to acute water deprivation for 24 or 48 h were studied on the acetylcholinesterase (AChE) activity of porcine brain and hypophysial regions. Mean ambient temperatures, respiratory rates and rectal temperatures in the open were significantly higher than inside the pen. Heat stress induced a rise in AChE activities in the pons, cerebellum, amygdala, hippocampus, hypothalamus, mid-brain and medulla oblongata. However, no significant changes were observed in the cerebral cortex, adenohypophysis and neurohypophysis. Water deprivation significantly ( Padenohypophysis and neurohypophysis were relatively unaffected.

  9. Structural Studies on Acetylcholinesterase and Paraoxonase Directed Towards Development of Therapeutic Biomolecules for the Treatment of Degenerative Diseases and Protection Against Chemical Threat Agents

    Sussman, Joel L.; Silman, Israel

    Acetylcholinesterase and paraoxonase are important targets for treatment of degenerative diseases, Alzheimer's disease and atherosclerosis, respectively, both of which impose major burdens on the health care systems in Western society. Acetylcholinesterase is the target of lethal nerve agents, and paraoxonase is under consideration as a bioscavenger for their detoxification. Both are thus the subject of research and development in the context of nerve agent toxicology. The crystal structures of the two enzymes are described, and structure/function relationships are discussed in the context of drug development and of development of means of protection against chemical threats.

  10. Chemical composition and in vitro evaluation of antimicrobial and anti-acetylcholinesterase properties of the flower oil of Ferula lutea.

    Znati, Mansour; Jabrane, Aymen; Hajlaoui, Hafedh; Harzallah-Skhiri, Fethia; Bouajila, Jalloul; Casanova, Joseph; Ben Jannet, Hichem

    2012-07-01

    The present work describes the chemical composition and evaluates the antimicrobial and the anti-acetylcholinesterase properties of the flower oil from the Tunisian Ferula lutea obtained by hydrodistillation and analyzed by combination of GC/FID and GC/MS. The chemical composition of the flower oil of this species is reported for the first time. Seventeen compounds were identified accounting for 94.3% of the total oil. The chemical composition of this essential oil was characterized by a high proportion of monoterpene hydrocarbons (80.4%) among which delta-3-carene (31.2%) and alpha-pinene (25.8%) were the predominant compounds. The oxygenated monoterpenes represent the second major fraction (12.0%), 2,3,6-trimethylbenzaldehyde (10.9%) being the predominant one. Furthermore, the isolated oil was tested for its antimicrobial activity using the disc-diffusion and the microdilution assays against six Gram-positive and five Gram-negative bacteria as well as towards eight Candida species. It was found that flower oil of F. lutea exhibited interesting antibacterial and anticandidal activity (MIC = 39 mcirog/mL against Escherichia coli, Staphylococcus aureus and S. epidermidis and MIC = 156 microg/mL against Candida albicans). The anti-acetylcholinesterase effect of this oil was also evaluated in this work. Results showed that this oil exhibits significant activity (IC50 =70.25 +/- 5.41 microg/mL).

  11. Synthesis, Characterization, Acetylcholinesterase Inhibition, Molecular Modeling and Antioxidant Activities of Some Novel Schiff Bases Derived from 1-(2-Ketoiminoethylpiperazines

    A. Hamid A. Hadi

    2011-11-01

    Full Text Available Some novel Schiff bases derived from 1-(2-ketoiminoethylpiperazines were synthesized and characterized by mass spectroscopy, FTIR, UV-Visible, 1H and 13C-NMR. The compounds were tested for inhibitory activities on human acetylcholinesterase (hAChE, antioxidant activities, acute oral toxicity and further studied by molecular modeling techniques. The study identified the compound (DHP to have the highest activity among the series in hAChE inhibition and DPPH assay while the compound LP revealed the highest activity in the FRAP assay. The hAChE inhibitory activity of DHP is comparable with that of propidium, a known AChE inhibitor. This high activity of DHP was checked by molecular modeling which showed that DHP could not be considered as a bivalent ligand due to its incapability to occupy the esteratic site (ES region of the 3D crystal structure of hAChE. The antioxidant study unveiled varying results in 1,1-diphenyl-1-picrylhydrazyl (DPPH and ferric reducing antioxidant power (FRAP assays. This indicates mechanistic variations of the compounds in the two assays. The potential therapeutic applications and safety of these compounds were suggested for use as human acetylcholinesterase inhibitors and antioxidants.

  12. Guarana (Paullinia cupana) ameliorates memory impairment and modulates acetylcholinesterase activity in Poloxamer-407-induced hyperlipidemia in rat brain.

    Ruchel, Jader B; Braun, Josiane B S; Adefegha, Stephen A; Guedes Manzoni, Alessandra; Abdalla, Fátima H; de Oliveira, Juliana S; Trelles, Kelly; Signor, Cristiane; Lopes, Sônia T A; da Silva, Cássia B; Castilhos, Lívia G; Rubin, Maribel A; Leal, Daniela B R

    2017-01-01

    Hyperlipidemia is a risk factor for the development of cognitive dysfunction and atherosclerosis. Natural compounds have recently received special attention in relation to the treatment of disease due to their low cost and wide margin of safety. Thus, the aim of this study was to determine the possible preventive effect of guarana powder (Paullinia cupana) on memory impairment and acetylcholinesterase (AChE) activity in the brain structures of rats with Poloxamer-407-induced hyperlipidemia. Adult male Wistar rats were pretreated with guarana (12.5, 25 and 50mg/kg/day) and caffeine (0.2mg/kg/day) by gavage for a period of 30days. Simvastatin (0.04mg/kg) was administered as a comparative standard. Acute hyperlipidemia was induced with intraperitoneal injections of 500mg/kg of Poloxamer-407. Memory tests and evaluations of anxiety were performed. The cortex, cerebellum, hippocampus, hypothalamus and striatum were separated to assess acetylcholinesterase activity. Our results revealed that guarana powder was able to reduce the levels of TC and LDL-C in a manner similar to simvastatin. Guarana powder also partially reduced the liver damage caused by hyperlipidemia. Guarana was able to prevent changes in the activity of AChE and improve memory impairment due to hyperlipidemia. Guarana powder may therefore be a source of promising phytochemicals that can be used as adjuvant therapy in the management of hyperlipidemia and cognitive disorders.

  13. Site-directed mutagenesis of an acetylcholinesterase gene from the yellow fever mosquito Aedes aegypti confers insecticide insensitivity.

    Vaughan, A; Rocheleau, T; ffrench-Constant, R

    1997-11-01

    Insecticide resistance is a serious problem facing the effective control of insect vectors of disease. Insensitive acetylcholinesterase (AChE) confers resistance to organophosphorus (OP) and carbamate insecticides and is a widespread resistance mechanism in vector mosquitoes. Although the point mutations that underlie AChE insensitivity have been described from Drosophila, the Colorado potato beetle, and house flies, no resistance associated mutations have been documented from mosquitoes to date. We are therefore using a cloned acetylcholinesterase gene from the yellow fever mosquito Aedes aegypti as a model in which to perform site directed mutagenesis in order to understand the effects of potential resistance associated mutations. The same resistance associated amino-acid replacements as found in other insects also confer OP and carbamate resistance to the mosquito enzyme. Here we describe the levels of resistance conferred by different combinations of these mutations and the effects of these mutations on the kinetics of the AChE enzyme. Over-expression of these constructs in baculovirus will facilitate purification of each of the mutant enzymes and a more detailed analysis of their associated inhibition kinetics.

  14. Highly Sensitive Detection of Organophosphate Insecticides Using Biosensors Based on Genetically Engineered Acetylcholinesterase and Poly(3,4-Ethylenedioxythiophene

    Tomasz Sikora

    2011-01-01

    Full Text Available A poly(3,4-ethylenedioxythiophene (PEDOT conducting ink is presented as a new electroactive material to be incorporated in acetylcholinesterase-(AChE- based screen printed biosensors, acting not only as a conducting template but also as an electrochemical mediator for thiocholine oxidation. Two different strategies have been studied for the chemical synthesis of PEDOT: (a a classical oxidative polymerisation and (b a more innovative enzymatic polymerisation, giving a water-soluble PEDOT. The use of this water-soluble conducting polymer as mediator in screen-printed biosensors enables its deposition by printing like the rest of the layers. Highly sensitive acetylcholinesterase-(AChE- based screen-printed biosensors have been constructed using both classical and enzymatic PEDOT, in combination with genetically modified AChE. These electrodes allow the measurement of thiocholine oxidation at potentials of 100 mV versus Ag/AgCl reference electrode through the mediation of PEDOT. Inhibition of thiocholine production in presence of CPO allow for detection of this pesticide in concentrations as low as 1·10−10 M.

  15. Quercetin Improves Neurobehavioral Performance Through Restoration of Brain Antioxidant Status and Acetylcholinesterase Activity in Manganese-Treated Rats.

    Adedara, Isaac A; Ego, Valerie C; Subair, Temitayo I; Oyediran, Oluwasetemi; Farombi, Ebenezer O

    2017-01-31

    The present study investigated the neuroprotective mechanism of quercetin by assessing the biochemical and behavioral characteristics in rats sub-chronically treated with manganese alone at 15 mg/kg body weight or orally co-treated with quercetin at 10 and 20 mg/kg body weight for 45 consecutive days. Locomotor behavior was monitored using video-tracking software during a 10-min trial in a novel environment whereas the brain regions namely the hypothalamus, cerebrum and cerebellum of the rats were processed for biochemical analyses. Results indicated that co-treatment with quercetin significantly (p < 0.05) prevented manganese-induced locomotor and motor deficits specifically the decrease in total distance travelled, total body rotation, maximum speed, absolute turn angle as well as the increase in time of immobility and grooming. The improvement in the neurobehavioral performance of manganese-treated rats following quercetin co-treatment was confirmed by track and occupancy plot analyses. Moreover, quercetin assuaged manganese-induced decrease in antioxidant enzymes activities and the increase in acetylcholinesterase activity, hydrogen peroxide generation and lipid peroxidation levels in the hypothalamus, cerebrum and cerebellum of the rats. Taken together, quercetin mechanisms of ameliorating manganese-induced neurotoxicity is associated with restoration of acetylcholinesterase activity, augmentation of redox status and inhibition of lipid peroxidation in brain of rats.

  16. Evolution of acetylcholinesterase and butyrylcholinesterase in the vertebrates: an atypical butyrylcholinesterase from the Medaka Oryzias latipes.

    Leo Pezzementi

    Full Text Available Acetylcholinesterase (AChE and butyrylcholinesterase (BChE are thought to be the result of a gene duplication event early in vertebrate evolution. To learn more about the evolution of these enzymes, we expressed in vitro, characterized, and modeled a recombinant cholinesterase (ChE from a teleost, the medaka Oryzias latipes. In addition to AChE, O. latipes has a ChE that is different from either vertebrate AChE or BChE, which we are classifying as an atypical BChE, and which may resemble a transitional form between the two. Of the fourteen aromatic amino acids in the catalytic gorge of vertebrate AChE, ten are conserved in the atypical BChE of O. latipes; by contrast, only eight are conserved in vertebrate BChE. Notably, the atypical BChE has one phenylalanine in its acyl pocket, while AChE has two and BChE none. These substitutions could account for the intermediate nature of this atypical BChE. Molecular modeling supports this proposal. The atypical BChE hydrolyzes acetylthiocholine (ATCh and propionylthiocholine (PTCh preferentially but butyrylthiocholine (BTCh to a considerable extent, which is different from the substrate specificity of AChE or BChE. The enzyme shows substrate inhibition with the two smaller substrates but not with the larger substrate BTCh. In comparison, AChE exhibits substrate inhibition, while BChE does not, but may instead show substrate activation. The atypical BChE from O. latipes also shows a mixed pattern of inhibition. It is effectively inhibited by physostigmine, typical of all ChEs. However, although the atypical BChE is efficiently inhibited by the BChE-specific inhibitor ethopropazine, it is not by another BChE inhibitor, iso-OMPA, nor by the AChE-specific inhibitor BW284c51. The atypical BChE is found as a glycophosphatidylinositol-anchored (GPI-anchored amphiphilic dimer (G(2 (a, which is unusual for any BChE. We classify the enzyme as an atypical BChE and discuss its implications for the evolution of ACh

  17. Rapid eye movement sleep deprivation induces an increase in acetylcholinesterase activity in discrete rat brain regions

    Benedito M.A.C.

    2001-01-01

    Full Text Available Some upper brainstem cholinergic neurons (pedunculopontine and laterodorsal tegmental nuclei are involved in the generation of rapid eye movement (REM sleep and project rostrally to the thalamus and caudally to the medulla oblongata. A previous report showed that 96 h of REM sleep deprivation in rats induced an increase in the activity of brainstem acetylcholinesterase (Achase, the enzyme which inactivates acetylcholine (Ach in the synaptic cleft. There was no change in the enzyme's activity in the whole brain and cerebrum. The components of the cholinergic synaptic endings (for example, Achase are not uniformly distributed throughout the discrete regions of the brain. In order to detect possible regional changes we measured Achase activity in several discrete rat brain regions (medulla oblongata, pons, thalamus, striatum, hippocampus and cerebral cortex after 96 h of REM sleep deprivation. Naive adult male Wistar rats were deprived of REM sleep using the flower-pot technique, while control rats were left in their home cages. Total, membrane-bound and soluble Achase activities (nmol of thiocholine formed min-1 mg protein-1 were assayed photometrically. The results (mean ± SD obtained showed a statistically significant (Student t-test increase in total Achase activity in the pons (control: 147.8 ± 12.8, REM sleep-deprived: 169.3 ± 17.4, N = 6 for both groups, P<0.025 and thalamus (control: 167.4 ± 29.0, REM sleep-deprived: 191.9 ± 15.4, N = 6 for both groups, P<0.05. Increases in membrane-bound Achase activity in the pons (control: 171.0 ± 14.7, REM sleep-deprived: 189.5 ± 19.5, N = 6 for both groups, P<0.05 and soluble enzyme activity in the medulla oblongata (control: 147.6 ± 16.3, REM sleep-deprived: 163.8 ± 8.3, N = 6 for both groups, P<0.05 were also observed. There were no statistically significant differences in the enzyme's activity in the other brain regions assayed. The present findings show that the increase in Achase activity

  18. Selective and irreversible inhibitors of mosquito acetylcholinesterases for controlling malaria and other mosquito-borne diseases.

    Yuan-Ping Pang

    Full Text Available New insecticides are urgently needed because resistance to current insecticides allows resurgence of disease-transmitting mosquitoes while concerns for human toxicity from current compounds are growing. We previously reported the finding of a free cysteine (Cys residue at the entrance of the active site of acetylcholinesterase (AChE in some insects but not in mammals, birds, and fish. These insects have two AChE genes (AP and AO, and only AP-AChE carries the Cys residue. Most of these insects are disease vectors such as the African malaria mosquito (Anopheles gambiae sensu stricto or crop pests such as aphids. Recently we reported a Cys-targeting small molecule that irreversibly inhibited all AChE activity extracted from aphids while an identical exposure caused no effect on the human AChE. Full inhibition of AChE in aphids indicates that AP-AChE contributes most of the enzymatic activity and suggests that the Cys residue might serve as a target for developing better aphicides. It is therefore worth investigating whether the Cys-targeting strategy is applicable to mosquitocides. Herein, we report that, under conditions that spare the human AChE, a methanethiosulfonate-containing molecule at 6 microM irreversibly inhibited 95% of the AChE activity extracted from An. gambiae s. str. and >80% of the activity from the yellow fever mosquito (Aedes aegypti L. or the northern house mosquito (Culex pipiens L. that is a vector of St. Louis encephalitis. This type of inhibition is fast ( approximately 30 min and due to conjugation of the inhibitor to the active-site Cys of mosquito AP-AChE, according to our observed reactivation of the methanethiosulfonate-inhibited AChE by 2-mercaptoethanol. We also note that our sulfhydryl agents partially and irreversibly inhibited the human AChE after prolonged exposure (>4 hr. This slow inhibition is due to partial enzyme denaturation by the inhibitor and/or micelles of the inhibitor, according to our studies using

  19. Heterologous amyloid seeding: revisiting the role of acetylcholinesterase in Alzheimer's disease.

    Létitia Jean

    Full Text Available Neurodegenerative diseases associated with abnormal protein folding and ordered aggregation require an initial trigger which may be infectious, inherited, post-inflammatory or idiopathic. Proteolytic cleavage to generate vulnerable precursors, such as amyloid-beta peptide (Abeta production via beta and gamma secretases in Alzheimer's Disease (AD, is one such trigger, but the proteolytic removal of these fragments is also aetiologically important. The levels of Abeta in the central nervous system are regulated by several catabolic proteases, including insulysin (IDE and neprilysin (NEP. The known association of human acetylcholinesterase (hAChE with pathological aggregates in AD together with its ability to increase Abeta fibrilization prompted us to search for proteolytic triggers that could enhance this process. The hAChE C-terminal domain (T40, AChE(575-614 is an exposed amphiphilic alpha-helix involved in enzyme oligomerisation, but it also contains a conformational switch region (CSR with high propensity for conversion to non-native (hidden beta-strand, a property associated with amyloidogenicity. A synthetic peptide (AChE(586-599 encompassing the CSR region shares homology with Abeta and forms beta-sheet amyloid fibrils. We investigated the influence of IDE and NEP proteolysis on the formation and degradation of relevant hAChE beta-sheet species. By combining reverse-phase HPLC and mass spectrometry, we established that the enzyme digestion profiles on T40 versus AChE(586-599, or versus Abeta, differed. Moreover, IDE digestion of T40 triggered the conformational switch from alpha- to beta-structures, resulting in surfactant CSR species that self-assembled into amyloid fibril precursors (oligomers. Crucially, these CSR species significantly increased Abeta fibril formation both by seeding the energetically unfavorable formation of amyloid nuclei and by enhancing the rate of amyloid elongation. Hence, these results may offer an explanation

  20. In silico pharmacophore model for tabun-inhibited acetylcholinesterase reactivators: a study of their stereoelectronic properties.

    Bhattacharjee, Apurba K; Kuca, Kamil; Musilek, Kamil; Gordon, Richard K

    2010-01-01

    Organophosphorus (OP) nerve agents that inhibit acetylcholinesterase (AChE; EC 3.1.1.7) function in the nervous system, causing acute intoxication. If untreated, death can result. Inhibited AChE can be reactivated by oximes, antidotes for OP exposure. However, OP intoxication caused by the nerve agent tabun (GA) is particularly resistant to oximes, which poorly reactivate GA-inhibited AChE. In an attempt to develop a rational strategy for the discovery and design of novel reactivators with lower toxicity and increased efficacy in reactivating GA-inhibited AChE, we developed the first in silico pharmacophore model for binding affinity of GA-inhibited AChE from a set of 11 oximes. Oximes were analyzed for stereoelectronic profiles and three-dimensional quantitative structure-activity relationship pharmacophores using ab initio quantum chemical and pharmacophore generation methods. Quantum chemical methods were sequentially used from semiempirical AM1 to hierarchical ab initio calculations to determine the stereoelectronic properties of nine oximes exhibiting affinity for binding to GA-inhibited AChE in vivo. The calculated stereoelectronic properties led us to develop the in silico pharmacophore model using CATALYST methodology. Specific stereoelectronic profiles including the distance between bisquarternary nitrogen atoms of the pyridinium ring in the oximes, hydrophilicity, surface area, nucleophilicity of the oxime oxygen, and location of the molecular orbitals on the isosurfaces have important roles for potencies for reactivating GA-inhibited AChE. The in silico pharmacophore model of oxime affinity for binding to GA-inhibited AChE was found to require a hydrogen bond acceptor, a hydrogen bond donor at the two terminal regions, and an aromatic ring in the central region of the oximes. The model was found to be well-correlated (R = 0.9) with experimental oxime affinity for binding to GA-inhibited AChE. Additional stereoelectronic features relating activity with

  1. The interactions of azure B, a metabolite of methylene blue, with acetylcholinesterase and butyrylcholinesterase

    Petzer, Anél, E-mail: 12264954@nwu.ac.za [Centre of Excellence for Pharmaceutical Sciences, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Harvey, Brian H. [Centre of Excellence for Pharmaceutical Sciences, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Petzer, Jacobus P. [Division of Pharmaceutical Chemistry, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa)

    2014-02-01

    Methylene blue (MB) is reported to possess diverse pharmacological actions and is attracting increasing attention for the treatment of neurodegenerative disorders such as Alzheimer's disease. Among the pharmacological actions of MB, is the significant inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). These activities may, at least in part, underlie MB's beneficial effects in Alzheimer's disease. MB is metabolized to yield N-demethylated products of which azure B, the monodemethyl metabolite, is the predominant species. Azure B has been shown to be pharmacologically active and also possesses a variety of biological actions. Azure B therefore may contribute to the pharmacological profile of MB. Based on these considerations, the present study investigates the possibility that azure B may, similar to MB, act as an inhibitor of human AChE and BuChE. The results document that azure B inhibits AChE and BuChE with IC{sub 50} values of 0.486 μM and 1.99 μM, respectively. The results further show that azure B inhibits AChE and BuChE reversibly, and that the modes of inhibition are most likely competitive. Although the AChE and BuChE inhibitory activities of azure B are twofold and fivefold, respectively, less potent than those recorded for MB [IC{sub 50}(AChE) = 0.214 μM; IC{sub 50}(BuChE) = 0.389 μM] under identical conditions, azure B may be a contributor to MB's in vivo activation of the cholinergic system and beneficial effects in Alzheimer's disease. - Highlights: • Methylene blue (MB) is a known inhibitor of AChE and BuChE. • Azure B, the major metabolite of MB, also is an inhibitor of AChE and BuChE. • Azure B may be a contributor to MB's in vivo activation of the cholinergic system. • Azure B may contribute to MB's potential in Alzheimer's disease therapy.

  2. Identification and Biochemical Properties of Two New Acetylcholinesterases in the Pond Wolf Spider (Pardosa pseudoannulata).

    Meng, Xiangkun; Li, Chunrui; Xiu, Chunli; Zhang, Jianhua; Li, Jingjing; Huang, Lixin; Zhang, Yixi; Liu, Zewen

    2016-01-01

    Acetylcholinesterase (AChE), an important neurotransmitter hydrolase in both invertebrates and vertebrates, is targeted by organophosphorus and carbamate insecticides. In this study, two new AChEs were identified in the pond wolf spider Pardosa pseudoannulata, an important predatory natural enemy of several insect pests. In total, four AChEs were found in P. pseudoannulata (including two AChEs previously identified in our laboratory). The new putative AChEs PpAChE3 and PpAChE4 contain most of the common features of the AChE family, including cysteine residues, choline binding sites, the conserved sequence 'FGESAG' and conserved aromatic residues but with a catalytic triad of 'SDH' rather than 'SEH'. Recombinant enzymes expressed in Sf9 cells showed significant differences in biochemical properties compared to other AChEs, such as the optimal pH, substrate specificity, and catalytic efficiency. Among three test substrates, PpAChE1, PpAChE3 and PpAChE4 showed the highest catalytic efficiency (Vmax/KM) for ATC (acetylthiocholine iodide), with PpAChE3 exhibiting a clear preference for ATC based on the VmaxATC/VmaxBTC ratio. In addition, the four PpAChEs were more sensitive to the AChE-specific inhibitor BW284C51, which acts against ATC hydrolysis, than to the BChE-specific inhibitor ISO-OMPA, which acts against BTC hydrolysis, with at least a 8.5-fold difference in IC50 values for each PpAChE. PpAChE3, PpAChE4, and PpAChE1 were more sensitive than PpAChE2 to the tested Carb insecticides, and PpAChE3 was more sensitive than the other three AChEs to the tested OP insecticides. Based on all the results, two new functional AChEs were identified from P. pseudoannulata. The differences in AChE sequence between this spider and insects enrich our knowledge of invertebrate AChE diversity, and our findings will be helpful for understanding the selectivity of insecticides between insects and natural enemy spiders.

  3. Layer-by-layer assembled carbon nanotube-acetylcholinesterase/biopolymer renewable interfaces: SPR and electrochemical characterization.

    Zhang, Yuanyuan; Arugula, Mary A; Kirsch, Jeffrey S; Yang, Xiaoyun; Olsen, Eric; Simonian, Aleksandr L

    2015-02-03

    Developing simple, reliable, and cost-effective methods of renewing an inhibited biocatalyst (e.g., enzymatic interfaces) on biosensors is needed to advance multiuse, reusable sensor applications. We report a method for the renewal of layer-by-layer (LbL) self-assembled inhibition-based enzymatic interfaces in multiwalled carbon nanotube (MWCNT) armored acetylcholinesterase (AChE) biosensors. The self-assembly process of MWCNT dispersed enzymes/biopolymers was investigated using surface plasmon resonance (SPR). The LbL fabrication consisted of alternating cushion layers of positively charged CNT-polyethylenimine (CNT-PEI) and negatively charged CNT-deoxyribonucleic acid (CNT-DNA) and a functional interface consisting of alternating layers of CNT-PEI and negatively charged CNT-acetylcholine esterase (CNT-AChE, pH 7.4). The observed SPR response signal increased while assembling the different layers, indicating the buildup of multiple layers on the Au surface. A partial desorption of the top enzymatic layer in the LbL structure was observed with a desorption strategy employing alkaline treatment. This indicates that the strong interaction of CNT-biopolymer conjugates with the Au surface was a result of both electrostatic interactions between biopolymers and the surface binding energy from CNTs: the closer the layers are to the Au surface, the stronger the interactions. In contrast, a similar LbL assembly of soluble enzyme/polyelectrolytes resulted in stronger desorption on the surface after the alkaline treatment; this led to the investigation of AChE layer removal, permanently inhibited after pesticide exposure on glassy carbon (GC) electrodes, while keeping the cushion layers intact. The desorption strategy permitted the SPR and electrochemical electrode surfaces to be regenerated multiple times by the subsequent self-assembly of fresh PEI/AChE layers. Flow-mode electrochemical amperometric analysis demonstrated good stability toward the determination of

  4. Identification and Biochemical Properties of Two New Acetylcholinesterases in the Pond Wolf Spider (Pardosa pseudoannulata.

    Xiangkun Meng

    Full Text Available Acetylcholinesterase (AChE, an important neurotransmitter hydrolase in both invertebrates and vertebrates, is targeted by organophosphorus and carbamate insecticides. In this study, two new AChEs were identified in the pond wolf spider Pardosa pseudoannulata, an important predatory natural enemy of several insect pests. In total, four AChEs were found in P. pseudoannulata (including two AChEs previously identified in our laboratory. The new putative AChEs PpAChE3 and PpAChE4 contain most of the common features of the AChE family, including cysteine residues, choline binding sites, the conserved sequence 'FGESAG' and conserved aromatic residues but with a catalytic triad of 'SDH' rather than 'SEH'. Recombinant enzymes expressed in Sf9 cells showed significant differences in biochemical properties compared to other AChEs, such as the optimal pH, substrate specificity, and catalytic efficiency. Among three test substrates, PpAChE1, PpAChE3 and PpAChE4 showed the highest catalytic efficiency (Vmax/KM for ATC (acetylthiocholine iodide, with PpAChE3 exhibiting a clear preference for ATC based on the VmaxATC/VmaxBTC ratio. In addition, the four PpAChEs were more sensitive to the AChE-specific inhibitor BW284C51, which acts against ATC hydrolysis, than to the BChE-specific inhibitor ISO-OMPA, which acts against BTC hydrolysis, with at least a 8.5-fold difference in IC50 values for each PpAChE. PpAChE3, PpAChE4, and PpAChE1 were more sensitive than PpAChE2 to the tested Carb insecticides, and PpAChE3 was more sensitive than the other three AChEs to the tested OP insecticides. Based on all the results, two new functional AChEs were identified from P. pseudoannulata. The differences in AChE sequence between this spider and insects enrich our knowledge of invertebrate AChE diversity, and our findings will be helpful for understanding the selectivity of insecticides between insects and natural enemy spiders.

  5. Probing the origins of human acetylcholinesterase inhibition via QSAR modeling and molecular docking.

    Simeon, Saw; Anuwongcharoen, Nuttapat; Shoombuatong, Watshara; Malik, Aijaz Ahmad; Prachayasittikul, Virapong; Wikberg, Jarl E S; Nantasenamat, Chanin

    2016-01-01

    Alzheimer's disease (AD) is a chronic neurodegenerative disease which leads to the gradual loss of neuronal cells. Several hypotheses for AD exists (e.g., cholinergic, amyloid, tau hypotheses, etc.). As per the cholinergic hypothesis, the deficiency of choline is responsible for AD; therefore, the inhibition of AChE is a lucrative therapeutic strategy for the treatment of AD. Acetylcholinesterase (AChE) is an enzyme that catalyzes the breakdown of the neurotransmitter acetylcholine that is essential for cognition and memory. A large non-redundant data set of 2,570 compounds with reported IC50 values against AChE was obtained from ChEMBL and employed in quantitative structure-activity relationship (QSAR) study so as to gain insights on their origin of bioactivity. AChE inhibitors were described by a set of 12 fingerprint descriptors and predictive models were constructed from 100 different data splits using random forest. Generated models afforded R (2), [Formula: see text] and [Formula: see text] values in ranges of 0.66-0.93, 0.55-0.79 and 0.56-0.81 for the training set, 10-fold cross-validated set and external set, respectively. The best model built using the substructure count was selected according to the OECD guidelines and it afforded R (2), [Formula: see text] and [Formula: see text] values of 0.92 ± 0.01, 0.78 ± 0.06 and 0.78 ± 0.05, respectively. Furthermore, Y-scrambling was applied to evaluate the possibility of chance correlation of the predictive model. Subsequently, a thorough analysis of the substructure fingerprint count was conducted to provide informative insights on the inhibitory activity of AChE inhibitors. Moreover, Kennard-Stone sampling of the actives were applied to select 30 diverse compounds for further molecular docking studies in order to gain structural insights on the origin of AChE inhibition. Site-moiety mapping of compounds from the diversity set revealed three binding anchors encompassing both hydrogen bonding and van der Waals

  6. Probing the origins of human acetylcholinesterase inhibition via QSAR modeling and molecular docking

    Shoombuatong, Watshara; Malik, Aijaz Ahmad; Prachayasittikul, Virapong; Wikberg, Jarl E.S.

    2016-01-01

    Alzheimer’s disease (AD) is a chronic neurodegenerative disease which leads to the gradual loss of neuronal cells. Several hypotheses for AD exists (e.g., cholinergic, amyloid, tau hypotheses, etc.). As per the cholinergic hypothesis, the deficiency of choline is responsible for AD; therefore, the inhibition of AChE is a lucrative therapeutic strategy for the treatment of AD. Acetylcholinesterase (AChE) is an enzyme that catalyzes the breakdown of the neurotransmitter acetylcholine that is essential for cognition and memory. A large non-redundant data set of 2,570 compounds with reported IC50 values against AChE was obtained from ChEMBL and employed in quantitative structure-activity relationship (QSAR) study so as to gain insights on their origin of bioactivity. AChE inhibitors were described by a set of 12 fingerprint descriptors and predictive models were constructed from 100 different data splits using random forest. Generated models afforded R2, \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}${Q}_{\\mathrm{CV }}^{2}$\\end{document}QCV2 and \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}${Q}_{\\mathrm{Ext}}^{2}$\\end{document}QExt2 values in ranges of 0.66–0.93, 0.55–0.79 and 0.56–0.81 for the training set, 10-fold cross-validated set and external set, respectively. The best model built using the substructure count was selected according to the OECD guidelines and it afforded R2, \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage

  7. Energetics of Ortho-7 (oxime drug translocation through the active-site gorge of tabun conjugated acetylcholinesterase.

    Vivek Sinha

    Full Text Available Oxime drugs translocate through the 20 Å active-site gorge of acetylcholinesterase in order to liberate the enzyme from organophosphorus compounds' (such as tabun conjugation. Here we report bidirectional steered molecular dynamics simulations of oxime drug (Ortho-7 translocation through the gorge of tabun intoxicated enzyme, in which time dependent external forces accelerate the translocation event. The simulations reveal the participation of drug-enzyme hydrogen bonding, hydrophobic interactions and water bridges between them. Employing nonequilibrium theorems that recovers the free energy from irreversible work done, we reconstruct potential of mean force along the translocation pathway such that the desired quantity represents an unperturbed system. The potential locates the binding sites and barriers for the drug to translocate inside the gorge. Configurational entropic contribution of the protein-drug binding entity and the role of solvent translational mobility in the binding energetics is further assessed.

  8. Pesticide use, erythrocyte acetylcholinesterase level and self-reported acute intoxication symptoms among vegetable farmers in Nepal

    Neupane, Dinesh; Jors, E.; Brandt, L.

    2014-01-01

    intoxication and Erythrocyte Acetylcholinesterase(AChE) levels among vegetable farmers with a control group of blood donors in Nepal. Methods: A cross-sectional study was carried out among 90 pesticide-exposed farmers and a control group of 90 blood donors. Participants were randomly selected and data were...... gathered through questionnaires, observation and blood test. Chi-square test, logistic regression and Student's t-test were used for data analysis to describe pesticide use and compare symptoms and AChE levels between the two groups. This study was approved by Nepal Health Research Council. Results......E level among farmers. Education and information of farmers should be undertaken to remediate these problems....

  9. Electrogravimetric real-time and in situ michaelis-menten enzymatic kinetics: progress curve of acetylcholinesterase hydrolysis.

    Bueno, Paulo R; Watanabe, Ailton M; Faria, Ronaldo C; Santos, Márcio L; Riccardi, Carla S

    2010-12-16

    A piezoelectric detection of enzyme-modified surface was performed under Michaelis-Menten presumptions of steady-state condition. The approach herein presented showed promise in the study of enzymatic kinetics by measuring the frequency changes associated with mass changes at the piezoelectric crystal surface. Likewise, real-time frequency shifts, that is, dΔf/dt, indicated the rate of products formation from enzymatic reaction. In this paper, acetylcholinesterase was used as the enzymatic model and acetylcholine as substrate. The enzymatic rate has its maximum value for a short time during the kinetic reaction, for instance, during the first ten minutes of the reaction time scale. The values found for the kinetic constant rate and Michaelis-Menten constant were (1.4 ± 0.8) 10(5) s(-1) and (5.2 ± 3) 10(-4) M, respectively, in agreement with the values found in classical Michaelis-Menten kinetic experiments.

  10. Acetylcholinesterase (AChE) gene modification in transgenic animals: functional consequences of selected exon and regulatory region deletion.

    Camp, Shelley; Zhang, Limin; Marquez, Michael; de la Torre, Brian; Long, Jeffery M; Bucht, Goran; Taylor, Palmer

    2005-12-15

    AChE is an alternatively spliced gene. Exons 2, 3 and 4 are invariantly spliced, and this sequence is responsible for catalytic function. The 3' alternatively spliced exons, 5 and 6, are responsible for AChE disposition in tissue [J. Massoulie, The origin of the molecular diversity and functional anchoring of cholinesterases. Neurosignals 11 (3) (2002) 130-143; Y. Li, S. Camp, P. Taylor, Tissue-specific expression and alternative mRNA processing of the mammalian acetylcholinesterase gene. J. Biol. Chem. 268 (8) (1993) 5790-5797]. The splice to exon 5 produces the GPI anchored form of AChE found in the hematopoietic system, whereas the splice to exon 6 produces a sequence that binds to the structural subunits PRiMA and ColQ, producing AChE expression in brain and muscle. A third alternative RNA species is present that is not spliced at the 3' end; the intron 3' of exon 4 is used as coding sequence and produces the read-through, unanchored form of AChE. In order to further understand the role of alternative splicing in the expression of the AChE gene, we have used homologous recombination in stem cells to produce gene specific deletions in mice. Alternatively and together exon 5 and exon 6 were deleted. A cassette containing the neomycin gene flanked by loxP sites was used to replace the exon(s) of interest. Tissue analysis of mice with exon 5 deleted and the neomycin cassette retained showed very low levels of AChE expression, far less than would have been anticipated. Only the read-through species of the enzyme was produced; clearly the inclusion of the selection cassette disrupted splicing of exon 4 to exon 6. The selection cassette was then deleted in exon 5, exon 6 and exons 5 + 6 deleted mice by breeding to Ella-cre transgenic mice. AChE expression in serum, brain and muscle has been analyzed. Another AChE gene targeted mouse strain involving a region in the first intron, found to be critical for AChE expression in muscle cells [S. Camp, L. Zhang, M. Marquez, B

  11. Interactions of acetylcholinesterase with salvianolic acid B and rosmarinic acid from Salvia miltiorhiza water extract investigated by NMR relaxation rate

    Guo Wei Yin; Yi Ming Li; Wei Wei; Shan Hao Jiang; Da Yuan Zhu; Wei Hong Du

    2008-01-01

    In order to understand whether the ameliorating effect on old ages memory disorder by the root of Salvia miltiorhiza is related to the acetylcholinesterase (AChE) inhibition, two main ingredients, salvianolic acid B (1) and rosmarinic acid (2), which were isolated from S. Miltiorhiza water extract, were investigated in vitro by NMR relaxation rate in this work. The results showed that the proton selective relaxation rates and the molecular rotational correlation time of proton pairs for compounds 1 and 2 increased significantly by adding of AChE in mixing solution. The study reveals that the two compounds might bind to the enzyme and have AChE inhibitory effect, which could contribute to the ameliorating effect at some extent on old ages memory disorder.

  12. Kinetic characters and resistance to inhibition of crude and purified brain acetylcholinesterase of three freshwater fishes by organophosphates.

    Shaonan, Li; Xianchuan, Xie; Guonian, Zhu; Yajun, Tan

    2004-07-14

    Acetylcholinesterase (AChE) was purified from the brain of three fresh-water fishes, topmouth gudgeon (Pseudorasbora parva), goldfish (Carassius auratus auratus) and rainbow trout (Oncorrhychus mykiss, formerly named Salmo gairdneri) by PEG2000/phosphate-salt two phases extraction, DEAE-Sephadex A-50 and Sephadex G-200 chromatography. Kinetic characters and resistance to inhibition of crude and purified enzymes by organophosphates were then studied. Although the crude enzyme from the trout displayed a different specific activity, kinetic curve, Vmax, and sensitivity to inhibition by oxidized malathion and triazopos compared with the two cyprinoids (i.e. topmouth gudgeon and goldfish), the purified enzymes of all the three species showed no significant difference in all aspects. The result suggested a negligible intrinsic difference of brain AChEs among the tested species.

  13. Brain acetylcholinesterase and its molecular forms in a precocial murid, Acomys cahirinus, and rat during post-natal development.

    Michalek, H; Pintor, A; Fortuna, S; Bisso, G M

    1984-01-01

    Brain acetylcholinesterase (AChE) and its molecular forms of a precocial murid, Acomys cahirinus, characterized by a large hippocampus, were measured during post-natal development and compared with rat. The activity of soluble AChE in Acomys increased slightly up to 4 weeks after birth. The total AChE activity increased somewhat more but, in rats, this increase was still greater. Three main molecular forms of AChE were separated by 7.5% polyacrylamide gel electrophoresis. Their close similarity to the rat AChE forms was assessed by gradient polyacrylamide gel electrophoresis and electrofocusing. Maturation of these forms, i.e., conversion of simple into more complex forms in the soluble fraction of AChE was, however, considerably delayed reaching only after 4 weeks the pattern comparable to that of rat.

  14. 7-Methoxytacrine-p-Anisidine Hybrids as Novel Dual Binding Site Acetylcholinesterase Inhibitors for Alzheimer’s Disease Treatment

    Jan Korabecny

    2015-12-01

    Full Text Available Alzheimer’s disease (AD is a debilitating progressive neurodegenerative disorder that ultimately leads to the patient’s death. Despite the fact that novel pharmacological approaches endeavoring to block the neurodegenerative process are still emerging, none of them have reached use in clinical practice yet. Thus, palliative treatment represented by acetylcholinesterase inhibitors (AChEIs and memantine are still the only therapeutics used. Following the multi-target directed ligands (MTDLs strategy, herein we describe the synthesis, biological evaluation and docking studies for novel 7-methoxytacrine-p-anisidine hybrids designed to purposely target both cholinesterases and the amyloid cascade. Indeed, the novel derivatives proved to be effective non-specific cholinesterase inhibitors showing non-competitive AChE inhibition patterns. This compounds’ behavior was confirmed in the subsequent molecular modeling studies.

  15. [Distribution of acetylcholinesterase activity in the digestive system of the gastropod molluscs Littorina littorea and Achatina fulica].

    Zaĭtseva, O V; Kuznetsova, T V

    2008-01-01

    With the use of the histochemical procedure for the demonstration of acetylcholinesterase (AchE) activity, the distribution cholinergic regulatory elements was studied in the esophagus, the pharynx, the stomach, the liver (the digestive gland) and the intestine in sea and terrestrial gastropod molluscs that differed in their general organization level, lifestyle, habitat and feeding type. In both molluscs, all the parts of the digestive tract contained the significant amount of intraepithelial AchE-positive cells of the open type, single subepithelial neurons and the nervous fibers localized among the muscle cells of the wall of the organs. The basal processes of the AchE-positive intraepithelial cells were shown to form the intraepithelial nerve plexus and to pass under the epithelium. The peculiarities and common principles in the distribution of the nervous elements detected, their possible function and the regulatory role in the digestion in gastropod molluscs and other animals are discussed.

  16. Chemical Characterization and Acetylcholinesterase Inhibition Potential of Volatile Components of Aerial Parts of Pluchea lanceolata (DC. Oliv. & Hiern

    Pooja Srivastava

    2015-06-01

    Full Text Available Pluchea lanceolata (DC. Oliv. & Hiern (Rasana is an important medicinal plant due to its usage in number of Ayurvedic formulations. First time, chemical composition of essential oil from the aerial part of P. lanceolata was analyzed by gas chromatography-mass spectrometry (GC-MS and NMR spectroscopy. Ex-vivo cholinesterase inhibitory activity of the essential oil was also evaluated using mouse brain homogenate. The major components were linalool (32.2%, β-caryophyllene (8.5%, α-terpineol (8.0%, spathulenol (7.4%, linalylacetate (5.6%, naphthalene, 1,6-dimethyl-4-(1-methylethyl- (4.3%, α-copaene (3.6%, epi-cubebol (3.6% and trans-α-bergamontene (3.1%. The experimental results showed that hydrodistilate of P. lanceolata significantly inhibited acetylcholinesterase activity (IC 50 value 2.54 ± 0.03 µg/mL.

  17. Study of Inhibition, Reactivation and Aging Processes of Pesticides Using Graphene Nanosheets/Gold Nanoparticles-Based Acetylcholinesterase Biosensor

    Zhang, Lin; Long, Linjuan; Zhang, Weiying; Du, Dan; Lin, Yuehe

    2012-09-10

    Organophosphate (OP) and carbamate pesticides exert their toxicity via attacking the hydroxyl moiety of serine in the 'active site' of acetylcholinesterase (AChE). In this paper we developed a stable AChE biosensor based on self-assembling AChE to graphene nanosheet (GN)-gold nanoparticles (AuNPs) nanocomposite electrode for investigation of inhibition, reactivation and aging processes of different pesticides. It is confirmed that pesticides can inhibit AChE in a short time. OPs poisoning is treatable with oximes while carbarmates exposure is insensitive to oximes. The proposed electrochemical approach thus provides a new simple tool for comparison of pesticide sensitivity and guide of therapeutic intervention.

  18. Inhibition of acetylcholinesterase activity in the terrestrial isopod Porcellio scaber as a biomarker of organophosphorus compounds in food.

    Stanek, Katja; Gabrijelcic, Elizabeta; Drobne, Damjana; Trebse, Polonca

    2003-09-01

    This paper describes the toxicity of organophosphorus pesticide diazinon in juvenile and adult terrestrial isopods Porcellio scaber (Isopoda, Crustacea). The woodlice were exposed to different concentrations of diazinon added to food (5, 10, 50, and 100 or 150 micrograms/g dry food). Weight change and food assimilation efficiency were determined two and four weeks after the exposure. The activity of acetylcholinesterase (AChE) in surviving animals was measured at the end of the experiment. The results show that woodlice exposed to diazinon do not significantly differ from controls in growth and feeding rate. The reduction of AChE activity was observed at the lowest diazinon exposure (5 and 10 micrograms/g dry food). These results suggest that AChE activity might prove a useful biomarker, indicating low levels of organophosphates in food.

  19. Energetics of Ortho-7 (oxime drug) translocation through the active-site gorge of tabun conjugated acetylcholinesterase.

    Sinha, Vivek; Ganguly, Bishwajit; Bandyopadhyay, Tusar

    2012-01-01

    Oxime drugs translocate through the 20 Å active-site gorge of acetylcholinesterase in order to liberate the enzyme from organophosphorus compounds' (such as tabun) conjugation. Here we report bidirectional steered molecular dynamics simulations of oxime drug (Ortho-7) translocation through the gorge of tabun intoxicated enzyme, in which time dependent external forces accelerate the translocation event. The simulations reveal the participation of drug-enzyme hydrogen bonding, hydrophobic interactions and water bridges between them. Employing nonequilibrium theorems that recovers the free energy from irreversible work done, we reconstruct potential of mean force along the translocation pathway such that the desired quantity represents an unperturbed system. The potential locates the binding sites and barriers for the drug to translocate inside the gorge. Configurational entropic contribution of the protein-drug binding entity and the role of solvent translational mobility in the binding energetics is further assessed.

  20. Combined approach to demonstrate acetylcholinesterase activity changes in the rat brain following tabun intoxication and its treatment.

    Bajgar, Jiri; Hajek, Petr; Kassa, Jiri; Slizova, Dasa; Krs, Otakar; Karasova, Jana Zdarova; Fusek, Josef; Capek, Lukas; Voicu, Victor A

    2012-01-01

    Reactivation effects of K203 and currently available oximes (obidoxime, HI-6) in combination with atropine on acetylcholinesterase activities in the brain parts of rats poisoned with tabun were studied. The activity was determined by quantitative histochemical and biochemical methods correlating between them very well. The tabun-induced changes in acetylcholinsterase activity as well as in reactivation potency of reactivators used were different in various parts of the brain. Pontomedullar area seems to be important for observed changes following tabun intoxication and its treatment. From the oximes studied, the reactivation effect of K203 was comparable with obidoxime; HI-6 was ineffective. Combination of bio- and histochemical methods allow fine differentiation among the action of different oximes following tabun poisoning.

  1. Acetylcholinesterase inhibitors for the treatment of Wernicke-Korsakoff syndrome--three further cases show response to donepezil.

    Cochrane, Murray; Cochrane, Ashley; Jauhar, Pramod; Ashton, Elizabeth

    2005-01-01

    Three patients diagnosed with Wernicke-Korsakoff syndrome were treated with the acetylcholinesterase inhibitor, donepezil, for periods of 6 to 8 months. Cognitive testing [Alzheimer's disease assessment scale-cognitive subscale (ADAS-Cog), Mini-mental state examination (MMSE), Clock drawing test and six item 2 min recall] and carer questionnaires [Informant Questionnaire (IQ Code), Neuropsychiatric inventory scale (NPI)] were performed at baseline, mid- and endpoint of the treatment period and post-discontinuation. Progressive partial improvement occurred in cognitive measurements through the treatment period, some of which was sustained after discontinuing donepezil. Carer questionnaires also indicated improvement. Confounding factors necessitate caution when attributing improvements to the medication, but these cases suggest that this option merits further investigation.

  2. Acetylcholinesterase inhibition, antioxidant activity and toxicity of Peumus boldus water extracts on HeLa and Caco-2 cell lines.

    Falé, P L; Amaral, F; Amorim Madeira, P J; Sousa Silva, M; Florêncio, M H; Frazão, F N; Serralheiro, M L M

    2012-08-01

    This work aimed to study the inhibition on acetylcholinesterase activity (AChE), the antioxidant activity and the toxicity towards Caco-2 and HeLa cells of aqueous extracts of Peumus Boldus. An IC(50) value of 0.93 mg/mL, for AChE inhibition, and EC(50) of 18.7 μg/mL, for the antioxidant activity, was determined. This activity can be attributed to glycosylated flavonoid derivatives detected, which were the main compounds, although boldine and other aporphine derivatives were also present. No changes in the chemical composition or the biochemical activities were found after gastrointestinal digestion. Toxicity of P. boldus decoction gave an IC(50) value 0.66 mg/mL for HeLa cells, which caused significant changes in the cell proteome profile.

  3. Feasibility of application of conductometric biosensor based on acetylcholinesterase for the inhibitory analysis of toxic compounds of different nature.

    Stepurska, K V; Soldatkin, Capital O Cyrillic О; Kucherenko, I S; Arkhypova, V M; Dzyadevych, S V; Soldatkin, A P

    2015-01-07

    This study was aimed at the development of a conductometric biosensor based on acetylcholinesterase considering the feasibility of its application for the inhibitory analysis of various toxicants. In this paper, the optimum conditions for enzyme immobilization on the transducer surface are selected as well as the optimum concentration of substrate for inhibitory analysis. Sensitivity of the developed biosensor to different classes of toxic compounds (organophosphorus pesticides, heavy metal ions, surfactants, aflatoxin, glycoalkaloids) was tested. It is shown that the developed biosensor can be successfully used for the analysis of pesticides and mycotoxins, as well as for determination of total toxicity of the samples. A new method of biosensor analysis of toxic substances of different classes in complex multicomponent aqueous samples is proposed.

  4. Use and disuse and the control of acetylcholinesterase activity in fast and slow twitch muscle of rat

    Dettbarn, W. D.; Groswald, D.; Gupta, R. C.; Misulis, K. E.

    1985-01-01

    The role of acetylcholinesterase (AChE) in neuromuscular transmission is relatively well established, little is known, however, of the mechanisms that regulate its synthesis and control its specific distribution in fast and slow muscle. Innervation plays an important role in the regulation of AChE and elimination of the influence of the nerve by surgical denervation results in a loss of AChE. The influences of the nerve and how they are mediated was investigated. It is suggested that muscle usage and other factors such as materials carried by axonal transport may participate in the regulation of this enzyme. The mechanisms that regulate AChE and its molecular forms in two functionally different forms are studied.

  5. Acetylcholinesterase accelerates assembly of amyloid-beta-peptides into Alzheimer's fibrils: possible role of the peripheral site of the enzyme.

    Inestrosa, N C; Alvarez, A; Pérez, C A; Moreno, R D; Vicente, M; Linker, C; Casanueva, O I; Soto, C; Garrido, J

    1996-04-01

    Acetylcholinesterase (AChE), an important component of cholinergic synapses, colocalizes with amyloid-beta peptide (A beta) deposits of Alzheimer's brain. We report here that bovine brain AChE, as well as the human and mouse recombinant enzyme, accelerates amyloid formation from wild-type A beta and a mutant A beta peptide, which alone produces few amyloid-like fibrils. The action of AChE was independent of the subunit array of the enzyme, was not affected by edrophonium, an active site inhibitor, but it was affected by propidium, a peripheral anionic binding site ligand. Butyrylcholinesterase, an enzyme that lacks the peripheral site, did not affect amyloid formation. Furthermore, AChE is a potent amyloid-promoting factor when compared with other A beta-associated proteins. Thus, in addition to its role in cholinergic synapses, AChE may function by accelerating A beta formation and could play a role during amyloid deposition in Alzheimer's brain.

  6. From traditional European medicine to discovery of new drug candidates for the treatment of dementia and Alzheimer's disease: acetylcholinesterase inhibitors.

    Russo, P; Frustaci, A; Del Bufalo, A; Fini, M; Cesario, A

    2013-01-01

    The leading Alzheimer's disease (AD) therapeutics to date involves inhibitors of acetylcholinesterase (AChE), which should, in principle, elevate cholinergic signaling and limit inflammation. In spite of the effectiveness in 20%-30% of AD patients, more attention has been paid to find new anti-AChE agents from medicinal plants. Galanthamine, contained in the bulbs and flowers of Galanthus and related genera like Narcissus, represents a good example. The aim of this study is to review the role of possible AChE inhibitors (AChEI) present in plants traditionally used in European medicine for improving memory. Starting from Galanthamine, properties of Melissa species, Salvia officinalis, Arnica chamissonis and Ruta graveolens are discussed to point to the role of these plants as potential sources for the development of therapeutic agents for AD.

  7. Effect of the methanol leaves extract of Clinacanthus nutans on the activity of acetylcholinesterase in male mice

    Lau KW; Lee SK; Chin JH

    2014-01-01

    Objective:To evaluate thein vivoeffect of14 d repeatedly oral administration ofClinacanthus nutans(C. nutans) methanol leaves extract(250 mg/kg,500 mg/kg and1000 mg/kg bw) on the acetylcholinesterase(AChE) activity in maleBalb/C mice.Method:First group was served as control group, orally treated with distilled water as vehicle and group2-4 were orally treated with a single daily dose of250 mg/kg,500 mg/kg and1000 mg/kg bw ofC. nutans extract, respectively for14 d.Each group consisted of six animals(n=6).The activity of acetylcholinesterase in brain, liver, kidney and heart of mice was determined according toEllman method(1961).Results:From the results obtained, theAChE activity was found to be highest in mice liver, followed by brain, kidney and heart.Methanol extract ofC. nutans leaves at250 mg/kg(P<0.001),500 mg/kg(P<0.001) and1000 mg/kg(P<0.001) showed a significant increase in theAChE activity in mice kidney, liver and heart.On the other hand, theAChE activity obtained from the mice brain showed insignificant difference between the control group and treatment group.However, there was no abnormal behavioural change and adverse effect related to the central nervous system observed in all treated mice during14 d experimentation period.Conclusion:In conclusion,14 d oral administration ofC. nutans was able to modulate cholinergic neurotransmission by activating AChE activity in mice kidney, liver and heart.Compounds that responsible for the induction of AChE activity in mice liver, heart and kidney and its mechanism needs to be elucidated.

  8. Inhibition and Larvicidal Activity of Phenylpropanoids from Piper sarmentosum on Acetylcholinesterase against Mosquito Vectors and Their Binding Mode of Interaction.

    Hematpoor, Arshia; Liew, Sook Yee; Chong, Wei Lim; Azirun, Mohd Sofian; Lee, Vannajan Sanghiran; Awang, Khalijah

    2016-01-01

    Aedes aegypti, Aedes albopictus and Culex quinquefasciatus are vectors of dengue fever and West Nile virus diseases. This study was conducted to determine the toxicity, mechanism of action and the binding interaction of three active phenylpropanoids from Piper sarmentosum (Piperaceae) toward late 3rd or early 4th larvae of above vectors. A bioassay guided-fractionation on the hexane extract from the roots of Piper sarmentosum led to the isolation and identification of three active phenylpropanoids; asaricin 1, isoasarone 2 and trans-asarone 3. The current study involved evaluation of the toxicity and acetylcholinesterase (AChE) inhibition of these compounds against Aedes aegypti, Aedes albopictus and Culex quinquefasciatus larvae. Asaricin 1 and isoasarone 2 were highly potent against Aedes aegypti, Aedes albopictus and Culex quinquefasciatus larvae causing up to 100% mortality at ≤ 15 μg/mL concentration. The ovicidal activity of asaricin 1, isoasarone 2 and trans-asarone 3 were evaluated through egg hatching. Asaricin 1 and isoasarone 2 showed potent ovicidal activity. Ovicidal activity for both compounds was up to 95% at 25μg/mL. Asaricin 1 and isoasarone 2 showed strong inhibition on acetylcholinesterase with relative IC50 values of 0.73 to 1.87 μg/mL respectively. These findings coupled with the high AChE inhibition may suggest that asaricin 1 and isoasarone 2 are neuron toxic compounds toward Aedes aegypti, Aedes albopictus and Culex quinquefasciatus. Further computational docking with Autodock Vina elaborates the possible interaction of asaricin 1 and isoasarone 2 with three possible binding sites of AChE which includes catalytic triads (CAS: S238, E367, H480), the peripheral sites (PAS: E72, W271) and anionic binding site (W83). The binding affinity of asaricin 1 and isoasarone 2 were relatively strong with asaricin 1 showed a higher binding affinity in the anionic pocket.

  9. Inhibition and Larvicidal Activity of Phenylpropanoids from Piper sarmentosum on Acetylcholinesterase against Mosquito Vectors and Their Binding Mode of Interaction

    Hematpoor, Arshia; Liew, Sook Yee; Chong, Wei Lim; Azirun, Mohd Sofian; Lee, Vannajan Sanghiran; Awang, Khalijah

    2016-01-01

    Aedes aegypti, Aedes albopictus and Culex quinquefasciatus are vectors of dengue fever and West Nile virus diseases. This study was conducted to determine the toxicity, mechanism of action and the binding interaction of three active phenylpropanoids from Piper sarmentosum (Piperaceae) toward late 3rd or early 4th larvae of above vectors. A bioassay guided-fractionation on the hexane extract from the roots of Piper sarmentosum led to the isolation and identification of three active phenylpropanoids; asaricin 1, isoasarone 2 and trans-asarone 3. The current study involved evaluation of the toxicity and acetylcholinesterase (AChE) inhibition of these compounds against Aedes aegypti, Aedes albopictus and Culex quinquefasciatus larvae. Asaricin 1 and isoasarone 2 were highly potent against Aedes aegypti, Aedes albopictus and Culex quinquefasciatus larvae causing up to 100% mortality at ≤ 15 μg/mL concentration. The ovicidal activity of asaricin 1, isoasarone 2 and trans-asarone 3 were evaluated through egg hatching. Asaricin 1 and isoasarone 2 showed potent ovicidal activity. Ovicidal activity for both compounds was up to 95% at 25μg/mL. Asaricin 1 and isoasarone 2 showed strong inhibition on acetylcholinesterase with relative IC50 values of 0.73 to 1.87 μg/mL respectively. These findings coupled with the high AChE inhibition may suggest that asaricin 1 and isoasarone 2 are neuron toxic compounds toward Aedes aegypti, Aedes albopictus and Culex quinquefasciatus. Further computational docking with Autodock Vina elaborates the possible interaction of asaricin 1 and isoasarone 2 with three possible binding sites of AChE which includes catalytic triads (CAS: S238, E367, H480), the peripheral sites (PAS: E72, W271) and anionic binding site (W83). The binding affinity of asaricin 1 and isoasarone 2 were relatively strong with asaricin 1 showed a higher binding affinity in the anionic pocket. PMID:27152416

  10. Salivary gland proteome analysis reveals modulation of anopheline unique proteins in insensitive acetylcholinesterase resistant Anopheles gambiae mosquitoes.

    Sylvie Cornelie

    Full Text Available Insensitive acetylcholinesterase resistance due to a mutation in the acetylcholinesterase (ace encoding ace-1 gene confers cross-resistance to organophosphate and carbamate insecticides in Anopheles gambiae populations from Central and West Africa. This mutation is associated with a strong genetic cost revealed through alterations of some life history traits but little is known about the physiological and behavioural changes in insects bearing the ace-1(R allele. Comparative analysis of the salivary gland contents between An. gambiae susceptible and ace-1(R resistant strains was carried out to charaterize factors that could be involved in modifications of blood meal process, trophic behaviour or pathogen interaction in the insecticide-resistant mosquitoes. Differential analysis of the salivary gland protein profiles revealed differences in abundance for several proteins, two of them showing major differences between the two strains. These two proteins identified as saglin and TRIO are salivary gland-1 related proteins, a family unique to anopheline mosquitoes, one of them playing a crucial role in salivary gland invasion by Plasmodium falciparum sporozoites. Differential expression of two other proteins previously identified in the Anopheles sialome was also observed. The differentially regulated proteins are involved in pathogen invasion, blood feeding process, and protection against oxidation, relevant steps in the outcome of malaria infection. Further functional studies and insect behaviour experiments would confirm the impact of the modification of the sialome composition on blood feeding and pathogen transmission abilities of the resistant mosquitoes. The data supports the hypothesis of alterations linked to insecticide resistance in the biology of the primary vector of human malaria in Africa.

  11. Acetylcholinesterase immobilization and characterization, and comparison of the activity of the porous silicon-immobilized enzyme with its free counterpart.

    Saleem, Muhammad; Rafiq, Muhammad; Seo, Sung-Yum; Lee, Ki Hwan

    2016-02-02

    A successful prescription is presented for acetylcholinesterase physically adsorbed on to a mesoporous silicon surface, with a promising hydrolytic response towards acetylthiocholine iodide. The catalytic behaviour of the immobilized enzyme was assessed by spectrophotometric bioassay using neostigmine methyl sulfate as a standard acetycholinesterase inhibitor. The surface modification was studied through field emission SEM, Fourier transform IR spectroscopy, energy-dispersive X-ray spectroscopy, cathode luminescence and X-ray photoelectron spectroscopy analysis, photoluminescence measurement and spectrophotometric bioassay. The porous silicon-immobilized enzyme not only yielded greater enzyme stability, but also significantly improved the native photoluminescence at room temperature of the bare porous silicon architecture. The results indicated the promising catalytic behaviour of immobilized enzyme compared with that of its free counterpart, with a greater stability, and that it aided reusability and easy separation from the reaction mixture. The porous silicon-immobilized enzyme was found to retain 50% of its activity, promising thermal stability up to 90°C, reusability for up to three cycles, pH stability over a broad pH of 4-9 and a shelf-life of 44 days, with an optimal hydrolytic response towards acetylthiocholine iodide at variable drug concentrations. On the basis of these findings, it was believed that the porous silicon-immobilized enzyme could be exploited as a reusable biocatalyst and for screening of acetylcholinesterase inhibitors from crude plant extracts and synthesized organic compounds. Moreover, the immobilized enzyme could offer a great deal as a viable biocatalyst in bioprocessing for the chemical and pharmaceutical industries, and bioremediation to enhance productivity and robustness.

  12. Inhibition and Larvicidal Activity of Phenylpropanoids from Piper sarmentosum on Acetylcholinesterase against Mosquito Vectors and Their Binding Mode of Interaction.

    Arshia Hematpoor

    Full Text Available Aedes aegypti, Aedes albopictus and Culex quinquefasciatus are vectors of dengue fever and West Nile virus diseases. This study was conducted to determine the toxicity, mechanism of action and the binding interaction of three active phenylpropanoids from Piper sarmentosum (Piperaceae toward late 3rd or early 4th larvae of above vectors. A bioassay guided-fractionation on the hexane extract from the roots of Piper sarmentosum led to the isolation and identification of three active phenylpropanoids; asaricin 1, isoasarone 2 and trans-asarone 3. The current study involved evaluation of the toxicity and acetylcholinesterase (AChE inhibition of these compounds against Aedes aegypti, Aedes albopictus and Culex quinquefasciatus larvae. Asaricin 1 and isoasarone 2 were highly potent against Aedes aegypti, Aedes albopictus and Culex quinquefasciatus larvae causing up to 100% mortality at ≤ 15 μg/mL concentration. The ovicidal activity of asaricin 1, isoasarone 2 and trans-asarone 3 were evaluated through egg hatching. Asaricin 1 and isoasarone 2 showed potent ovicidal activity. Ovicidal activity for both compounds was up to 95% at 25μg/mL. Asaricin 1 and isoasarone 2 showed strong inhibition on acetylcholinesterase with relative IC50 values of 0.73 to 1.87 μg/mL respectively. These findings coupled with the high AChE inhibition may suggest that asaricin 1 and isoasarone 2 are neuron toxic compounds toward Aedes aegypti, Aedes albopictus and Culex quinquefasciatus. Further computational docking with Autodock Vina elaborates the possible interaction of asaricin 1 and isoasarone 2 with three possible binding sites of AChE which includes catalytic triads (CAS: S238, E367, H480, the peripheral sites (PAS: E72, W271 and anionic binding site (W83. The binding affinity of asaricin 1 and isoasarone 2 were relatively strong with asaricin 1 showed a higher binding affinity in the anionic pocket.

  13. Evaluation of potency of known oximes (pralidoxime, trimedoxime, HI-6, methoxime, obidoxime) to in vitro reactivate acetylcholinesterase inhibited by pesticides (chlorpyrifos and methylchlorpyrifos) and nerve agent (Russian VX).

    Musílek, Kamil; Kuca, Kamil; Jun, Daniel

    2007-01-01

    Nerve agents and pesticides belong to the group of organophosphates. They are able to inhibit irreversibly the enzyme acetylcholinesterase (AChE). Acetylcholinesterase reactivators were designed for the treatment of nerve agent intoxications. Their potency to reactivate pesticide-inhibited AChE was many times evaluated. In this study, five commonly used AChE reactivators (pralidoxime, methoxime, HI-6, obidoxime, trimedoxime) for the reactivation of AChE inhibited by two pesticides (chlorpyrifos and methylchlorpyrifos) were used. Russian VX (nerve agent) as a member of nerve agents' family was taken for comparison. Obtained results show that oximes developed against nerve agent intoxication are less effective for intoxication with organophosphorus pesticides. Especially, methylchlorpyrifos-inhibited AChE was found to be poorly reactivated by the compounds used.

  14. 2-(2-(4-Benzoylpiperazin-1-ylethylisoindoline-1,3-dione derivatives: Synthesis, docking and acetylcholinesterase inhibitory evaluation as anti-alzheimer agents

    Ahmad Mohammadi-Farani

    2017-01-01

    Full Text Available Objective(s: Alzheimer’s disease (AD as progressive cognitive decline and the most common form of dementia is due to degeneration of the cholinergic neurons in the brain. Therefore, administration of the acetylcholinesterase (AChE inhibitors such as donepezil is the first choice for treatment of the AD. In the present study, we focused on the synthesis and anti-cholinesterase evaluation of new donepezil like analogs. Materials and Methods: A new series of phthalimide derivatives (compounds 4a-4j were synthesized via Gabriel protocol and subsequently amidation reaction was performed using various benzoic acid derivatives. Then, the corresponding anti-acetylcholinesterase activity of the prepared derivatives (4a-4j was assessed by utilization of the Ellman's test and obtained results were compared to donepezil. Besides, docking study was also carried out to explore the likely in silico binding interactions.  Results: According to the obtained results, electron withdrawing groups (Cl, F at position 3 and an electron donating group (methoxy at position 4 of the phenyl ring enhanced the acetylcholinesterase inhibitory activity. Compound 4e (m-Fluoro, IC50 = 7.1 nM and 4i (p-Methoxy, IC50 = 20.3 nM were the most active compounds in this series and exerted superior potency than donepezil (410 nM. Moreover, a similar binding mode was observed in silico for all ligands in superimposition state with donepezil into the active site of acetylcholinesterase. Conclusion: Studied compounds could be potential leads for discovery of novel anti-Alzheimer agents in the future.

  15. Reactivation steps by 2-PAM of tabun-inhibited human acetylcholinesterase: reducing the computational cost in hybrid QM/MM methods.

    da Silva Gonçalves, Arlan; França, Tanos Celmar Costa; Caetano, Melissa Soares; Ramalho, Teodorico Castro

    2014-01-01

    The present work describes a simple integrated Quantum Mechanics/Molecular Mechanics method developed to study the reactivation steps by pralidoxime (2-PAM) of acetylcholinesterase (AChE) inhibited by the neurotoxic agent Tabun. The method was tested on an AChE model and showed to be able to corroborate most of the results obtained before, through a more complex and time-consuming methodology, proving to be suitable to this kind of mechanistic study at a lower computational cost.

  16. Nicotinic and muscarinic agonists and acetylcholinesterase inhibitors stimulate a common pathway to enhance GluN2B-NMDAR responses

    Ishibashi, Masaru; Yamazaki, Yoshihiko; Miledi, Ricardo; Sumikawa, Katumi

    2014-01-01

    The cellular mechanisms by which nicotinic and muscarinic cholinergic systems facilitate learning and memory largely remain to be elucidated. This study identified a common signaling pathway stimulated by cognitive-enhancing drugs targeted to nicotinic and m1 muscarinic receptors and acetylcholinesterase. Stimulation of this signaling pathway induces significant increases in glutamate receptor, ionotropic, N-methyl D-aspartate 2B (GluN2B)-containing NMDA receptor (NMDAR)-mediated responses at...

  17. Intraperitoneal Exposure to Nano/Microparticles of Fullerene (C60) Increases Acetylcholinesterase Activity and Lipid Peroxidation in Adult Zebrafish (Danio rerio) Brain

    Gonzalo Ogliari Dal Forno; Luiza Wilges Kist; Mariana Barbieri de Azevedo; Rachel Seemann Fritsch; Talita Carneiro Brandão Pereira; Roberta Socoowski Britto; Sílvia Stanisçuaski Guterres; Irene Clemes Külkamp-Guerreiro; Carla Denise Bonan; José María Monserrat; Maurício Reis Bogo

    2013-01-01

    Even though technologies involving nano/microparticles have great potential, it is crucial to determine possible toxicity of these technological products before extensive use. Fullerenes C60 are nanomaterials with unique physicochemical and biological properties that are important for the development of many technological applications. The aim of this study was to evaluate the consequences of nonphotoexcited fullerene C60 exposure in brain acetylcholinesterase expression and activity, antioxi...

  18. Inhibition of acetylcholinesterase, beta-amyloid aggregation, and NMDA receptors in Alzheimer's disease: a promising direction for the multi-target-directed ligands gold rush.

    Rosini, Michela; Simoni, Elena; Bartolini, Manuela; Cavalli, Andrea; Ceccarini, Luisa; Pascu, Nicoleta; McClymont, David W; Tarozzi, Andrea; Bolognesi, Maria L; Minarini, Anna; Tumiatti, Vincenzo; Andrisano, Vincenza; Mellor, Ian R; Melchiorre, Carlo

    2008-08-14

    Alzheimer's disease (AD) is a multifactorial syndrome with several target proteins contributing to its etiology. To confront AD, an innovative strategy is to design single chemical entities able to simultaneously modulate more than one target. Here, we present compounds that inhibit acetylcholinesterase and NMDA receptor activity. Furthermore, these compounds inhibit AChE-induced Abeta aggregation and display antioxidant properties, emerging as lead candidates for treating AD.

  19. Chemical composition and acetylcholinesterase inhibitory activity of essential oils of Myrceugenia myrcioides(Cambess.) O. Berg and Eugenia riedelianaO. Berg, Myrtaceae

    2010-01-01

    The chemical composition of volatile oils from two Myrtaceae species, Myrceugenia myrcioidesand Eugenia riedeliana, both native from the Brazilian Atlantic Rain Forest, was analyzed by GC-MS. Acetylcholinesterase inhibitory activity was colorimetrically evaluated for these oils. For M. myrcioides, monoterpene hydrocarbons represented the major class in the volatile oil, with α-pinene as the most abundant component and a weak inhibitory activity was observed, whilst for E. riedeliana sesq...

  20. Validating the importance of two acetylcholinesterases in insecticide sensitivities by RNAi in Pardosa pseudoannulata, an important predatory enemy against several insect pests.

    Meng, Xiangkun; Li, Chunrui; Bao, Haibo; Fang, Jichao; Liu, Zewen; Zhang, Yixi

    2015-11-01

    The pond wolf spider (Pardosa pseudoannulata) is an important predatory enemy against several insect pests and showed relative different sensitivities to organophosphate and carbamate insecticides compared to insect pests. In our previous studies, two acetylcholinesterases were identified in P. pseudoannulata and played important roles in insecticide sensitivities. In order to understand the contributions of the two acetylcholinesterases to insecticide sensitivities, we firstly employed the RNAi technology in the spider. For a suitable microinjection RNAi method, the injection site, injection volume and interference time were optimized, which then demonstrated that the injection RNAi method was applicable in this spider. With the new RNAi method, it was revealed that both Pp-AChE1 and Pp-AChE2, encoded by genes Ppace1 and Ppace2, were the targets of organophosphate insecticides, but Pp-AChE1 would be more important. In contrast, the carbamate acted selectively on Pp-AChE1. The results showed that Pp-AChE1 was the major catalytic enzyme in P. pseudoannulata and the major target of organophosphate and carbamate insecticides. In a word, an RNAi method was established in the pond wolf spider, which further validated the importance of two acetylcholinesterases in insecticide sensitivities in this spider.

  1. Shift in aggregation, ROS generation, antioxidative defense, lysozyme and acetylcholinesterase activities in the cells of an Indian freshwater sponge exposed to washing soda (sodium carbonate).

    Mukherjee, Soumalya; Ray, Mitali; Ray, Sajal

    2016-09-01

    Washing soda, chemically identified as anhydrous sodium carbonate, is a popular cleaning agent among the rural and urban populations of India which often contaminates the freshwater ponds and lakes, the natural habitat of sponge Eunapius carteri. Present investigation deals with estimation of cellular aggregation, generation of ROS and activities of antioxidant enzymes, lysozyme and acetylcholinesterase in the cells of E. carteri under the environmentally realistic concentrations of washing soda. Prolonged treatment of washing soda inhibited the degree of cellular aggregation. Experimental exposure of 8 and 16mg/l of sodium carbonate for 48h elevated the physiological level of reactive oxygen species (ROS) generation in the agranulocytes, semigranulocytes and granulocytes of E. carteri, whereas, treatment of 192h inhibited the ROS generation in three cellular morphotypes. Activities of superoxide dismutase, catalase and glutathione-S-transferase were recorded to be inhibited under prolonged exposure of washing soda. Washing soda mediated inhibition of ROS generation and depletion in the activities of antioxidant enzymes were indicative to an undesirable shift in cytotoxic status and antioxidative defense in E. carteri. Inhibition in the activity of lysozyme under the treatment of sodium carbonate was suggestive to a severe impairment of the innate immunological efficiency of E. carteri distributed in the washing soda contaminated habitat. Washing soda mediated inhibition in the activity of acetylcholinesterase indicated its neurotoxicity in E. carteri. Washing soda, a reported environmental contaminant, affected adversely the immunophysiological status of E. carteri with reference to cellular aggregation, oxidative stress, antioxidative defense, lysozyme and acetylcholinesterase activity.

  2. Acetylcholinesterase Reactivators (HI-6, Obidoxime, Trimedoxime, K027, K075, K127, K203, K282: Structural Evaluation of Human Serum Albumin Binding and Absorption Kinetics

    Filip Zemek

    2013-08-01

    Full Text Available Acetylcholinesterase (AChE reactivators (oximes are compounds predominantly targeting the active site of the enzyme. Toxic effects of organophosphates nerve agents (OPNAs are primarily related to their covalent binding to AChE and butyrylcholinesterase (BChE, critical detoxification enzymes in the blood and in the central nervous system (CNS. After exposure to OPNAs, accumulation of acetylcholine (ACh overstimulates receptors and blocks neuromuscular junction transmission resulting in CNS toxicity. Current efforts at treatments for OPNA exposure are focused on non-quaternary reactivators, monoisonitrosoacetone oximes (MINA, and diacylmonoxime reactivators (DAM. However, so far only quaternary oximes have been approved for use in cases of OPNA intoxication. Five acetylcholinesterase reactivator candidates (K027, K075, K127, K203, K282 are presented here, together with pharmacokinetic data (plasma concentration, human serum albumin binding potency. Pharmacokinetic curves based on intramuscular application of the tested compounds are given, with binding information and an evaluation of structural relationships. Human Serum Albumin (HSA binding studies have not yet been performed on any acetylcholinesterase reactivators, and correlations between structure, concentration curves and binding are vital for further development. HSA bindings of the tested compounds were 1% (HI-6, 7% (obidoxime, 6% (trimedoxime, and 5%, 10%, 4%, 15%, and 12% for K027, K075, K127, K203, and K282, respectively.

  3. Evaluation of a Brain Acetylcholinesterase Extraction Method and Kinetic Constants after Methyl-Paraoxon Inhibition in Three Brazilian Fish Species

    Freitas, A. P.; Santos, C. R.; Sarcinelli, P. N.; Hauser-Davis, R. A.; Lopes, R. M.

    2016-01-01

    Acetylcholinesterase (AChE) is an important enzyme in the control of the neuronal action potential and sensitive to organophosphate inhibition. Brain fish AChE is less sensitive to organophosphate inhibition than AChE from terrestrial animals, although this sensitivity is variable among species and has not yet been fully evaluated in fish species. In this setting, inhibition kinetic constants for progressive irreversible inhibition of brain acetylcholinesterase due to methyl-paraoxon exposure were determined in three fish species (Mugil liza, Genidens genidens and Lagocephalus laevigatus) and hen (Gallus domesticus). Enzyme extraction using a detergent was shown to be adequate, and samples presented activity inhibition in high substrate concentrations and suppression of inhibition by methyl-paraoxon in the presence of the substrate, similar to kinetic patterns from purified enzyme preparations. Catfish (G. genidens) AChE presented the highest sensitivity among the evaluated fish species (IC50 = 1031.20 nM ± 63.17) in comparison to M. liza and L. laevigatus (IC50: 2878.83 ± 421.94 and 2842.5 ± 144.63 nM respectively). The lower dissociation constant (Kd = 20.3 ± 2.95 μM) of catfish AChE showed greater enzyme affinity for methyl-paraoxon, explaining this species higher sensitivity to organophosphates. Hen AChE presented higher ki (900.57 ± 65.3 mM-1min-1) and, consequently, greater sensitivity to methyl-paraoxon, explained by a lower Kd (0.6 ± 0.13 μM). Furthermore, hen AChE did not differentiate between the propionylthiocholine and acetylthiocholine substrates, indicating easier access of methyl-paraoxon to the hen enzyme activity site. The results obtained herein indicate a suitable extraction of AChE and, despite different inhibition kinetic constants, demonstrate that fish AChE is less sensitive to methyl-paraoxon, probably due to reduced access to the catalytic center which provides greater enzyme substrate selectivity. PMID:27655611

  4. Comparison of the oxime-induced reactivation of rhesus monkey, swine and guinea pig erythrocyte acetylcholinesterase following inhibition by sarin or paraoxon, using a perfusion model for the real-time determination of membrane-bound acetylcholinesterase activity.

    Herkert, Nadja M; Lallement, Guy; Clarençon, Didier; Thiermann, Horst; Worek, Franz

    2009-04-28

    Recently, a dynamically working in vitro model with real-time determination of membrane-bound human acetylcholinesterase (AChE) activity was shown to be a versatile model to investigate oxime-induced reactivation kinetics of organophosphate- (OP) inhibited enzyme. In this assay, AChE was immobilized on particle filters which were perfused with acetylthiocholine, Ellman's reagent and phosphate buffer. Subsequently, AChE activity was continuously analyzed in a flow-through detector. Now, it was an intriguing question whether this model could be used with erythrocyte AChE from other species in order to investigate kinetic interactions in the absence of annoying side reactions. Rhesus monkey, swine and guinea pig erythrocytes were a stable and highly reproducible enzyme source. Then, the model was applied to the reactivation of sarin- and paraoxon-inhibited AChE by obidoxime or HI 6 and it could be shown that the derived reactivation rate constants were in good agreement to previous results obtained from experiments with a static model. Hence, this dynamic model offers the possibility to investigate highly reproducible interactions between AChE, OP and oximes with human and animal AChE.

  5. Presymptomatic Treatment with Acetylcholinesterase Antisense Oligonucleotides Prolongs Survival in ALS (G93A-SOD1 Mice

    Gotkine Marc

    2013-01-01

    Full Text Available Objective. Previous research suggests that acetylcholinesterase (AChE may be involved in ALS pathogenesis. AChE enzyme inhibitors can upregulate AChE transcription which in certain contexts can have deleterious (noncatalytic effects, making them theoretically harmful in ALS, whilst AChE antisense-oligonucleotides (mEN101, which downregulate AChE may be beneficial. Our aim was to investigate whether downregulation of AChE using mEN101 is beneficial in an ALS mouse model. Methods. ALS (G93A-SOD1 mice received saline, mEN101, inverse-EN101, or neostigmine. Treatments were administered from 5 weeks. Disease-onset and survival were recorded. Additional mice were sacrificed for pathological analysis at 15 weeks of age. In a follow-up experiment treatment was started at the symptomatic stage at a higher dose. Results. mEN101 given at the presymptomatic (but not symptomatic stage prolonged survival and attenuated motor-neuron loss in ALS mice. In contrast, neostigmine exacerbated the clinical parameters. Conclusions. These results suggest that AChE may be involved in ALS pathogenesis. The accelerated disease course with neostigmine suggests that any beneficial effects of mEN101 occur through a non-catalytic rather than cholinergic mechanism.

  6. A first principle study on the interaction between acetylcholinesterase and acetylcholine, and also rivastigmine in alzheimer's disease case

    Khoirunisa, V.; Rusydi, F.; Kasai, H.; Gandaryus, A. G.; Dipojono, H. K.

    2016-08-01

    The catalytic activity of acetylcholinesterase enzyme (AChE) relates to the symptom progress in Alzheimer's disease. Interaction of AChE with rivastigmine (from the medicine) can reduce its catalytic activity toward acetylcholine to decelerate the progression of Alzheimer's disease. This research attempts to study the interaction between AChE and rivastigmine, and also acetylcholine (without the presence of rivastigmine) using density functional theory by simplifying the reaction occurs in the active site, which is assumed to be C2H5OH, C3N2H3(Ch3), and CH3COO-. The results suggest that AChE interacts easier with acetylcholine than with rivastigmine, which implies that the medicine does not effectively reduce the catalytic activity of AChE. At this stage, no experimental data is available to be compared with the calculation results. Nonetheless, this study has shown a good prospect to understand the AChE-substrate interaction using a first-principles calculation.

  7. An acetylcholinesterase (AChE) biosensor with enhanced solvent resistance based on chitosan for the detection of pesticides.

    Warner, John; Andreescu, Silvana

    2016-01-01

    Solvent tolerance of immobilized enzymes is important for many biosensing and biotechnological applications. In this paper we report an acetylcholinesterase (AChE) biosensor based on chitosan that exhibits high solvent resistance and enables sensitive detection of pesticides in presence of a high content of organic solvents. The solvent effect was established comparatively for the enzyme immobilized in chitosan and covalently cross-linked with glutaraldehyde. The activity of the immobilized AChE was dependent on the immobilization method and solvent type. The enzyme entrapped in chitosan fully conserved its activity in up to 25% methanol, 15% acetonitrile and 100% cyclohexane while the enzyme cross-linked with glutaraldehyde gradually lost its activity starting at 5% acetonitrile and methanol, and showed variable levels in cyclohexane. The detection limits of the biosensor for paraoxon were: 7.5 nM in 25% methanol, 100 nM in 15% acetonitrile and 2.5 μM in 100% cyclohexane. This study demonstrates that chitosan provides an excellent immobilization environment for AChE biosensors designed to operate in environments containing high amounts of organic solvents. It also highlights the effect of the immobilization material and solvent type on enzyme stability. These findings can enable future selection of the immobilization matrix and solvent type for the development of organic phase enzyme based systems.

  8. Acute effects of chlorpyryphos-ethyl and secondary treated effluents on acetylcholinesterase and butyrylcholinesterase activities in Carcinus maenas

    Jihene Ghedira; Jamel Jebali; Zied Bouraoui; Mohamed Banni; Lassaad Chouba; Hamadi Boussetta

    2009-01-01

    The acute effects of commercial formulation of chlorpyrifos-ethyl (Dursban(r)) and the secondary treated industrial/urban effluent (STIUE) exposure on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities in hepatopancreas and gills of Mediterranean crab Carcinus maenas were investigated. After 2 d of exposure to chlorpyriphos-ethyl, the AChE activity was inhibited in both organs at concentrations of 3.12 and 7.82 μg/L, whereas the BuChE was inhibited only at higher concentration 7.82 μg/L of commercial preparation Dursban(r). The exposure of crabs to Dursban(r) (3.12 μg/L) showed a significant decrement of AChE activity at 24 and 48 h, whereas the BuChE was inhibited only after 24 h and no inhibition for both enzymes was observed after 72 h. Moreover, a significant repression of AChE activity was observed in both organs of C. maenas exposed to 5% of STIUE. Our experiments indicated that the measurement of AChE activity in gills and hepatopancreas of C. meanas would be useful biomarker of organophosphorous (OP) and of neurotoxic effects of STIUE in Tunisia.

  9. Alkaloid metabolite profiles by GC/MS and acetylcholinesterase inhibitory activities with binding-mode predictions of five Amaryllidaceae plants.

    Cortes, Natalie; Alvarez, Rafael; Osorio, Edison H; Alzate, Fernando; Berkov, Strahil; Osorio, Edison

    2015-01-01

    Acetylcholinesterase (AChE) enzymatic inhibition is an important target for the management of Alzheimer disease (AD) and AChE inhibitors are the mainstay drugs for its treatment. In order to discover new sources of potent AChE inhibitors, a combined strategy is presented based on AChE-inhibitory activity and chemical profiles by GC/MS, together with in silico studies. The combined strategy was applied on alkaloid extracts of five Amaryllidaceae species that grow in Colombia. Fifty-seven alkaloids were detected using GC/MS, and 21 of them were identified by comparing their mass-spectral fragmentation patterns with standard reference spectra in commercial and private library databases. The alkaloid extracts of Zephyranthes carinata exhibited a high level of inhibitory activity (IC50 = 5.97 ± 0.24 μg/mL). Molecular modeling, which was performed using the structures of some of the alkaloids present in this extract and the three-dimensional crystal structures of AChE derived from Torpedo californica, disclosed their binding configuration in the active site of this AChE. The results suggested that the alkaloids 3-epimacronine and lycoramine might be of interest for AChE inhibition. Although the galanthamine group is known for its potential utility in treating AD, the tazettine-type alkaloids should be evaluated to find more selective compounds of potential benefit for AD.

  10. Exercise effects on activities of Na(+),K(+)-ATPase, acetylcholinesterase and adenine nucleotides hydrolysis in ovariectomized rats.

    Ben, Juliana; Soares, Flávia Mahatma Schneider; Cechetti, Fernanda; Vuaden, Fernanda Cenci; Bonan, Carla Denise; Netto, Carlos Alexandre; Wyse, Angela Terezinha de Souza

    2009-12-11

    Hormone deficiency following ovariectomy causes activation of Na(+),K(+)-ATPase and acetylcholinesterase (AChE) that has been related to cognitive deficits in experimental animals. Considering that physical exercise presents neuroprotector effects, we decide to investigate whether exercise training would affect enzyme activation in hippocampus and cerebral cortex, as well as adenosine nucleotide hydrolysis in synaptosomes from cerebral cortex of ovariectomized rats. Female adult Wistar rats were assigned to one of the following groups: sham (submitted to surgery without removal of the ovaries), exercise, ovariectomized (Ovx) and Ovx plus exercise. Thirty days after surgery, animals were submitted to one month of exercise training, three times per week. After, rats were euthanized, blood serum was collected and hippocampus and cerebral cortex were dissected. Data demonstrated that exercise reversed the activation of Na(+),K(+)-ATPase and AChE activities both in hippocampus and cerebral cortex of ovariectomized rats. Ovariectomy decreased AMP hydrolysis in cerebral cortex and did not alter adenine nucleotides hydrolysis in blood serum. Exercise per se decreased ADP and AMP hydrolysis in cerebral cortex. On the other hand, AMP hydrolysis in blood serum was increased by exercise in ovariectomized adult rats. Present data support that physical exercise might have beneficial effects and constitute a therapeutic alternative to hormone replacement therapy for estrogen deprivation.

  11. Acetylcholinesterases from the Disease Vectors Aedes aegypti and Anopheles gambiae: Functional Characterization and Comparisons with Vertebrate Orthologues.

    Cecilia Engdahl

    Full Text Available Mosquitoes of the Anopheles (An. and Aedes (Ae. genus are principal vectors of human diseases including malaria, dengue and yellow fever. Insecticide-based vector control is an established and important way of preventing transmission of such infections. Currently used insecticides can efficiently control mosquito populations, but there are growing concerns about emerging resistance, off-target toxicity and their ability to alter ecosystems. A potential target for the development of insecticides with reduced off-target toxicity is the cholinergic enzyme acetylcholinesterase (AChE. Herein, we report cloning, baculoviral expression and functional characterization of the wild-type AChE genes (ace-1 from An. gambiae and Ae. aegypti, including a naturally occurring insecticide-resistant (G119S mutant of An. gambiae. Using enzymatic digestion and liquid chromatography-tandem mass spectrometry we found that the secreted proteins were post-translationally modified. The Michaelis-Menten constants and turnover numbers of the mosquito enzymes were lower than those of the orthologous AChEs from Mus musculus and Homo sapiens. We also found that the G119S substitution reduced the turnover rate of substrates and the potency of selected covalent inhibitors. Furthermore, non-covalent inhibitors were less sensitive to the G119S substitution and differentiate the mosquito enzymes from corresponding vertebrate enzymes. Our findings indicate that it may be possible to develop selective non-covalent inhibitors that effectively target both the wild-type and insecticide resistant mutants of mosquito AChE.

  12. Rosmarinus officinalis L. leaf extract improves memory impairment and affects acetylcholinesterase and butyrylcholinesterase activities in rat brain.

    Ozarowski, Marcin; Mikolajczak, Przemyslaw L; Bogacz, Anna; Gryszczynska, Agnieszka; Kujawska, Malgorzata; Jodynis-Liebert, Jadwiga; Piasecka, Anna; Napieczynska, Hanna; Szulc, Michał; Kujawski, Radoslaw; Bartkowiak-Wieczorek, Joanna; Cichocka, Joanna; Bobkiewicz-Kozlowska, Teresa; Czerny, Boguslaw; Mrozikiewicz, Przemyslaw M

    2013-12-01

    Rosmarinus officinalis L. leaf as part of a diet and medication can be a valuable proposal for the prevention and treatment of dementia. The aim of the study was to assess the effects of subchronic (28-fold) administration of a plant extract (RE) (200 mg/kg, p.o.) on behavioral and cognitive responses of rats linked with acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity and their mRNA expression level in the hippocampus and frontal cortex. The passive avoidance test results showed that RE improved long-term memory in scopolamine-induced rats. The extract inhibited the AChE activity and showed a stimulatory effect on BuChE in both parts of rat brain. Moreover, RE produced a lower mRNA BuChE expression in the cortex and simultaneously an increase in the hippocampus. The study suggests that RE led to improved long-term memory in rats, which can be partially explained by its inhibition of AChE activity in rat brain.

  13. Double layer structure-based virtual screening reveals 3'-Hydroxy-A-Naphthoflavone as novel inhibitor candidate of human acetylcholinesterase

    Ichsan, Mochammad; Pangastuti, Ardini; Habibi, Mohammad Wildan; Juliana, Kartika

    2016-03-01

    One of the most effective target for Alzheimer's disease's (AD) treatment is the inhibition of human acetylcholinesterase (hAChE) eventhough it has many side effects. So that, this study was aimed to discover a new candidate of hAChE's inhibitor that has more negative binding affinity than existing drugs. hAChE's 3D model used in this study has a good quality according to its number of residues in most favoured regions (92%), three bad contacts, >50 ERRAT's score (85,870) and successfully passed the VERIFY 3D threshold (>80%). Based on the first layer of SBVS againts more than 12.180.630 ligands, we discovered 11.806 hits and then we found 359 hits from the second layer of SBVS. Based on our previous steps, we found that 3'-Hydroxy-a-Naphthoflavone was the only one candidate, that directly interacted with Trp286 via hydrogen bond and hydrophobic interactions and also has the most negative binding affinity (-10,6 kcal/mol) and also has more negative than existing hAChE's inhibitors, such as tacrine, donepezil, etc. 3'-Hydroxy-a-Naphthoflavone is the best candidate of hAChE's inhibitor based on its binding affinity (-10,6 kcal/mol) that is more negative than existing hAChE's inhibitors, such as tacrine, donepezil, etc.

  14. Insecticidal properties of essential oils against Tribolium castaneum (Herbst) and their inhibitory effects on acetylcholinesterase and adenosine triphosphatases.

    Abou-Taleb, Hamdy K; Mohamed, Magdy I E; Shawir, Mohamed S; Abdelgaleil, Samir A M

    2016-01-01

    Essential oils from 20 Egyptian plants were obtained by using hydrodistillation. The chemical composition of the isolated oils was identified by gas chromatograph/mass spectrometer. Fumigant and contact toxicities of the essential oils were evaluated against the adults of Tribolium castaneum. In fumigation assays, the oil of Origanum vulgare (LC50 = 9.97 mg/L air) displayed the highest toxicity towards the adults of T. castaneum. In contact assays, the oils of Artemisia monosperma (LC50 = 0.07 mg/cm(2)) and O. vulgare (LC50 = 0.07 mg/cm(2)) were the most potent toxicants against the adults of T. castaneum. Biochemical studies showed that the tested oils caused pronounced inhibition of acetylcholinesterase (AChE) and adenosine triphosphatases (ATPases) isolated from the larvae of T. castaneum. The oil Cupressus macrocarpa (IC50 = 12.3 mg/L) was the most potent inhibitor of AChE, while the oil of Calistemon viminals (IC50 = 4.4 mg/L) was the most potent inhibitor of ATPases.

  15. Effects of the herbicides clomazone, quinclorac, and metsulfuron methyl on acetylcholinesterase activity in the silver catfish (Rhamdia quelen) (Heptapteridae).

    dos Santos Miron, Denise; Crestani, Márcia; Rosa Shettinger, Maria; Maria Morsch, Vera; Baldisserotto, Bernardo; Angel Tierno, Miguel; Moraes, Gilberto; Vieira, Vania Lucia Pimentel

    2005-07-01

    Fingerlings of the silver catfish (Rhamdia quelen) were exposed to three herbicides widely used in rice culture in south Brazil: clomazone, quinclorac, and metsulfuron methyl. LC50 was determined and acetylcholinesterase (AChE) activity was evaluated in brain and muscle tissue of fish exposed to different herbicide concentrations after 96h (short term). The LC50 value (nominal concentration) was 7.32 mg/L for clomazone and 395 mg/L for quinclorac, but was not obtained for metsulfuron-methyl since all fingerlings survived the highest concentration of 1200 mg/L. Brain and muscle AChE activity in unexposed fish were 17.9 and 9.08 micromol/min/g protein, respectively. Clomazone significantly inhibited AChE activity in both tissues, achieving maximal inhibition of about 83% in brain and 89% in muscle tissue. In contrast, quinclorac and metsulfuron methyl caused increases in enzyme activity in the brain (98 and 179%, respectively) and inhibitions in muscle tissue (88 and 56%, respectively). This study demonstrated short-term effects of exposure to environmentally relevant concentrations of rice field herbicides on AChE activity in brain and muscle tissue of silver catfish.

  16. Benefits of statistical molecular design, covariance analysis, and reference models in QSAR: a case study on acetylcholinesterase.

    Andersson, C David; Hillgren, J Mikael; Lindgren, Cecilia; Qian, Weixing; Akfur, Christine; Berg, Lotta; Ekström, Fredrik; Linusson, Anna

    2015-03-01

    Scientific disciplines such as medicinal- and environmental chemistry, pharmacology, and toxicology deal with the questions related to the effects small organic compounds exhort on biological targets and the compounds' physicochemical properties responsible for these effects. A common strategy in this endeavor is to establish structure-activity relationships (SARs). The aim of this work was to illustrate benefits of performing a statistical molecular design (SMD) and proper statistical analysis of the molecules' properties before SAR and quantitative structure-activity relationship (QSAR) analysis. Our SMD followed by synthesis yielded a set of inhibitors of the enzyme acetylcholinesterase (AChE) that had very few inherent dependencies between the substructures in the molecules. If such dependencies exist, they cause severe errors in SAR interpretation and predictions by QSAR-models, and leave a set of molecules less suitable for future decision-making. In our study, SAR- and QSAR models could show which molecular sub-structures and physicochemical features that were advantageous for the AChE inhibition. Finally, the QSAR model was used for the prediction of the inhibition of AChE by an external prediction set of molecules. The accuracy of these predictions was asserted by statistical significance tests and by comparisons to simple but relevant reference models.

  17. Structure of a prereaction complex between the nerve agent sarin, its biological target acetylcholinesterase, and the antidote HI-6.

    Allgardsson, Anders; Berg, Lotta; Akfur, Christine; Hörnberg, Andreas; Worek, Franz; Linusson, Anna; Ekström, Fredrik J

    2016-05-17

    Organophosphorus nerve agents interfere with cholinergic signaling by covalently binding to the active site of the enzyme acetylcholinesterase (AChE). This inhibition causes an accumulation of the neurotransmitter acetylcholine, potentially leading to overstimulation of the nervous system and death. Current treatments include the use of antidotes that promote the release of functional AChE by an unknown reactivation mechanism. We have used diffusion trap cryocrystallography and density functional theory (DFT) calculations to determine and analyze prereaction conformers of the nerve agent antidote HI-6 in complex with Mus musculus AChE covalently inhibited by the nerve agent sarin. These analyses reveal previously unknown conformations of the system and suggest that the cleavage of the covalent enzyme-sarin bond is preceded by a conformational change in the sarin adduct itself. Together with data from the reactivation kinetics, this alternate conformation suggests a key interaction between Glu202 and the O-isopropyl moiety of sarin. Moreover, solvent kinetic isotope effect experiments using deuterium oxide reveal that the reactivation mechanism features an isotope-sensitive step. These findings provide insights into the reactivation mechanism and provide a starting point for the development of improved antidotes. The work also illustrates how DFT calculations can guide the interpretation, analysis, and validation of crystallographic data for challenging reactive systems with complex conformational dynamics.

  18. [Effects of the association of sulbutiamine with an acetylcholinesterase inhibitor in early stage and moderate Alzheimer disease].

    Ollat, H; Laurent, B; Bakchine, S; Michel, B-F; Touchon, J; Dubois, B

    2007-01-01

    The efficacy of the inhibitors of acetylcholinesterase in Alzheimer's Disease (AD) is moderated and some patients do not respond to these treatments. Sulbutiamine potentializes cholinergic and glutamatergic transmissions, mainly in hippocampus and prefrontal cortex. This multicentric, randomized and double-blind trial evaluates the effects of the association of sulbutiamine to an anticholinesterasic drug in cognitive functions in patients with AD at an early stage (episodic memory, working memory, executive functions, attention). Patients had first donepezil (D) or sulbutiamine (S) during three months. During this period, only attention improved in both groups. During the three following months, a placebo (P) in patients D and donepezil in patients S were added. Compared to entry results, episodic memory decreased in group D + P but improved in group S + D. At the same time the improvement of attention persisted in both groups. Daylife activities only improved in group S + D. In conclusion sulbutiamine can be an adjuvant to treatment in early stage and moderate AD by anticholinesterasic drugs.

  19. Reactivation of organophosphate-inhibited human, Cynomolgus monkey, swine and guinea pig acetylcholinesterase by MMB-4: a modified kinetic approach.

    Worek, Franz; Wille, Timo; Aurbek, Nadine; Eyer, Peter; Thiermann, Horst

    2010-12-15

    Treatment of poisoning by highly toxic organophosphorus compounds (OP, nerve agents) is a continuous challenge. Standard treatment with atropine and a clinically used oxime, obidoxime or pralidoxime is inadequate against various nerve agents. For ethical reasons testing of oxime efficacy has to be performed in animals. Now, it was tempting to investigate the reactivation kinetics of MMB-4, a candidate oxime to replace pralidoxime, with nerve agent-inhibited acetylcholinesterase (AChE) from human and animal origin in order to provide a kinetic basis for the proper assessment of in vivo data. By applying a modified kinetic approach, allowing the use of necessary high MMB-4 concentrations, it was possible to determine the reactivation constants with sarin-, cyclosarin-, VX-, VR- and tabun-inhibited AChE. MMB-4 exhibited a high reactivity and low affinity towards OP-inhibited AChE, except of tabun-inhibited enzyme where MMB-4 had an extremely low reactivity. Species differences between human and animal AChE were low (Cynomolgus) to moderate (swine, guinea pig). Due to the high reactivity of MMB-4 a rapid reactivation of inhibited AChE can be anticipated at adequate oxime concentrations which are substantially higher compared to HI-6. Additional studies are necessary to determine the in vivo toxicity, tolerability and pharmacokinetics of MMB-4 in humans in order to enable a proper assessment of the value of this oxime as an antidote against nerve agent poisoning.

  20. Kinetic analysis of interactions of paraoxon and oximes with human, Rhesus monkey, swine, rabbit, rat and guinea pig acetylcholinesterase.

    Worek, Franz; Aurbek, Nadine; Wille, Timo; Eyer, Peter; Thiermann, Horst

    2011-01-15

    Previous in vitro studies showed marked species differences in the reactivating efficiency of oximes between human and animal acetylcholinesterase (AChE) inhibited by organophosphorus (OP) nerve agents. These findings provoked the present in vitro study which was designed to determine the inhibition, aging, spontaneous and oxime-induced reactivation kinetics of the pesticide paraoxon, serving as a model compound for diethyl-OP, and the oximes obidoxime, pralidoxime, HI 6 and MMB-4 with human, Rhesus monkey, swine, rabbit, rat and guinea pig erythrocyte AChE. Comparable results were obtained with human and monkey AChE. Differences between human, swine, rabbit, rat and guinea pig AChE were determined for the inhibition and reactivation kinetics. A six-fold difference of the inhibitory potency of paraoxon with human and guinea pig AChE was recorded while only moderate differences of the reactivation constants between human and animal AChE were determined. Obidoxime was by far the most effective reactivator with all tested species. Only minor species differences were found for the aging and spontaneous reactivation kinetics. The results of the present study underline the necessity to determine the inhibition, aging and reactivation kinetics in vitro as a basis for the development of meaningful therapeutic animal models, for the proper assessment of in vivo animal data and for the extrapolation of animal data to humans.

  1. Cyclic voltammetric acetylcholinesterase biosensor for the detection of captan in apple samples with the aid of chemometrics.

    Nesakumar, Noel; Sethuraman, Swaminathan; Krishnan, Uma Maheswari; Rayappan, John Bosco Balaguru

    2015-06-01

    The presence of captan residues in apples shows high toxicity, which often causes eye and skin irritation, dermatitis, conjunctivitis, and vomiting in humans. In this context, an electrochemical biosensor based on acetylcholinesterase (AChE) immobilized on a ZnO nanorod interface has been proposed. In this work, Hill, dose-response, and first-, second-, and third-order polynomial regression models were successfully applied and the prediction ability of these models was tested with the use of current density obtained from the cyclic voltammograms of appropriate captan solutions. The Pt/ZnO/AChE bioelectrode showed a high sensitivity of 0.538 μA cm(-2) μM(-1) in the linear range from 0.05 to 25.0 μM with a limit of detection of 107 nM. The recovery results were observed between 98.4 and 102.4 % from the apple sample. This work provides a new promising tool for the detection of captan in apple samples.

  2. Local salt substitutes "Obu-otoyo" activate acetylcholinesterase and butyrylcholinesterase and induce lipid peroxidation in rat brain.

    Akinyemi, Ayodele J; Oboh, Ganiyu; Ademiluyi, Adedayo O

    2015-09-01

    Evidence has shown that ingestion of heavy metals can lead to neurodegenerative diseases. This study aimed to investigate the neurotoxic potential of salt substitutes (Obu-Otoyo); salt A (made by burning palm kernel shaft then soaked in water overnight and the extract from the resulting residue is used as the salt substitute) and salt B (an unrefined salt mined from a local site at Ilobu town, Osun-State, Nigeria) by assessing their effect on some key enzymes linked with neurodegenerative disease [acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities] as well as on malondialdehyde (MDA) content of the rat brain. Salt substitutes were fed to normal rats as dietary inclusion at doses of 0.5 and 1.0% for 30 days. Thereafter, the effect of the salt substitutes on AChE and BChE activities as well as on MDA level in the rat brain was determined. The results revealed that the salt substitutes caused a significant (psalt substitutes on AChE and BChE activities could be attributed to the presence of some toxic heavy metals. Therefore, the ability of the salt substitutes to induce lipid peroxidation and activate AChE and BChE activities could provide some possible mechanism for their neurotoxic effect.

  3. A comparative study on the relationship between acetylcholinesterase activity and acute toxicity in Daphnia magna exposed to anticholinesterase insecticides.

    Printes, Liane Biehl; Callaghan, Amanda

    2004-05-01

    Acetylcholinesterase (AChE) activity was measured in Daphnia magna that had been exposed to four organophosphates (OPs; parathion, chlorpyrifos, malathion, and acephate) and one carbamate (propoxur) for 48 h. These results were related to acute toxicity (median effective concentration [EC50] for immobility). For the four OPs, the EC50s were 7.03 pM, 3.17 pM, 10.56 pM, and 309.82 microM, respectively. The EC50 for propoxur was 449.90 pM. Reduction in AChE activity was directly related to an increase in immobility in all chemicals tested. However, the ratio between the EC50 and the AChE median inhibiting concentration ranged from 0.31 to 0.90. A 50% reduction in AChE activity generally was associated with detrimental effects on mobility. However, for acephate, high levels of AChE inhibition (70%) were observed in very low concentrations and were not associated with immobility. In addition, increasing the concentration of acephate further had a slight negative effect on AChE activity but a strong detrimental effect on mobility. Binding sites other than AChE possibly are involved in acephate toxicity to D. magna. Our findings demonstrate different associations between AChE inhibition and toxicity when different chemicals are compared. Therefore, the value of using AChE activity as a biomarker in D. magna will be dependent on the chemical tested.

  4. Exploring the physicochemical properties of oxime-reactivation therapeutics for cyclosarin, sarin, tabun, and VX inactivated acetylcholinesterase.

    Esposito, Emilio Xavier; Stouch, Terry R; Wymore, Troy; Madura, Jeffry D

    2014-01-21

    The inactivation of acetylcholinesterase (AChE) by organophosphorus agent (OP) compounds is a serious problem regardless of how the individual was exposed. The reactivation of OP-inactivated AChE is dependent on the OP conjugate, and commonly a specific oxime is better at reactivating a specific OP conjugate than several diverse OP conjugates. The presented research explores the physicochemical properties needed for the reactivation of OP-inactivated AChE. Four different OPs, cyclosarin, sarin, tabun, and VX, were analyzed using the same set of oxime reactivators. A trial descriptor pool of semiempirical, traditional, and molecular interaction field descriptors was used to construct an ensemble of QSAR models for each OP-conjugate pair. Based on the molecular information and the cross-validation ability, individual QSAR models were selected to be part of an OP-conjugate consensus model. The OP-conjugate specific models provide important insight into the physicochemical properties required to reactivate the OP conjugates of interest. The reactivation of AChE inactivated with either cyclosarin or tabun requires the oxime therapeutic to possess an overall polar-positive surface area. Oxime therapeutics for the reactivation of sarin-inactivated AChE are conformationally dependent while oxime reverse therapeutics for VX require a compact region with a highly hydrophilic region and two positively charged pyridine rings.

  5. Effect of five acetylcholinesterase reactivators on tabun-intoxicated rats: induction of oxidative stress versus reactivation efficacy.

    Pohanka, Miroslav; Karasova, Jana Zdarova; Musilek, Kamil; Kuca, Kamil; Kassa, Jiri

    2009-08-01

    Oxime reactivators HI-6, obidoxime, trimedoxime, K347 and K628 were investigated as drugs designed for treatment of tabun intoxication. The experiments were performed on rats in order to simulate real conditions. Rats were intoxicated with one LD(50 )of tabun and treated with atropine and mentioned reactivators. Activities of erythrocyte acetylcholinesterase (AChE), plasma butyrylcholinesterase (BChE) and brain AChE were measured as markers of reactivation efficacy. An estimation of low molecular weight antioxidant levels using cyclic voltammetry was the second examination parameter. The evaluation of cholinesterases activity showed good reactivation potency of blood AChE and plasma BChE by commercially available obidoxime and newly synthesized K347. The potency of oximes to reactivate brain AChE was lower due to the poor blood-brain barrier penetration of used compounds. Commercially available reactivator HI-6 and newly synthesized K628 caused oxidative stress measured by cyclic voltammetry as antioxidant level. The oxidative stress provoked by HI-6 and K628 was found to be significant on probability level P = 0.05. The others reactivators did not affect antioxidant levels.

  6. Synthesis and evaluation of novel analogues of vitamin B6 as reactivators of tabun and paraoxon inhibited acetylcholinesterase.

    Gaso-Sokac, Dajana; Katalinić, Maja; Kovarik, Zrinka; Busić, Valentina; Kovac, Spomenka

    2010-09-06

    A series of novel pyridinium oximes was prepared by reactions of quaternization of pyridoxal oxime with substituted phenacyl bromides in acetone at room temperature. The structures of compounds were determined according to the data obtained by IR spectroscopy, mass spectrometry, (1)H and (13)C nuclear magnetic resonance spectroscopy as well as by elemental analysis. We tested pyridoxal oxime (1) and five prepared oximes in 1mM concentration as reactivators of human erythrocytes acetylcholinesterase (AChE) inhibited by organophosphorus compounds tabun and paraoxon: 1-phenacyl-3-hydroxy-4-hydroxyiminomethyl-5-hydroxymethyl-2-methylpyridinium bromide (2), 1-(4'-chlorophenacyl)-3-hydroxy-4-hydroxyiminomethyl-5-hydroxymethyl-2-methylpyridinium bromide (3), 1-(4'-fluorophenacyl)-3-hydroxy-4-hydroxyiminomethyl-5-hydroxymethyl-2-methylpyridinium bromide (4), 3-hydroxy-4-hydroxyiminomethyl-5-hydroxymethyl-2-methyl-1-(4'-methylphenacyl)pyridinium bromide (5), 3-hydroxy-4-hydroxyiminomethyl-5-hydroxymethyl-2-methyl-1-(4'-methoxyphenacyl)pyridinium bromide (6). However, tested oximes were not efficient in reactivation of either tabun or paraoxon inhibited AChE. The maximum restored enzyme activity in 24h was below 25%. Therefore, this class of compounds cannot be considered as potential improvement in a search for new and more efficient antidotes against OP poisoning.

  7. Structural modifications of dicationic acetylcholinesterase reactivators studied under ion-pairing mechanism in reversed-phase liquid chromatography.

    Radulescu, Medeea; Kuca, Kamil; Musilek, Kamil; David, Victor

    2014-11-01

    A study focused on the chromatographic behavior of several acetylcholinesterase reactivators under ion-pairing mechanism is reported. Among these reactivators, dicationic oximes and carbamoyl-based pyridinium congeners were studied, which form ion pairs with alkylsulfonate anions. This mechanism was studied for some major experimental parameters, such as the chain length of the ion-pairing agent added to the aqueous phase, its concentration, temperature, and nature of the organic modifier from mobile phase. Retention data showed one or two possibilities of forming ion pairs and the tautomerism of the studied reactivators, for different pH values of the aqueous component. Double sigmoid shapes were obtained for the studied compounds for the dependence between retention factor and pH, indicating the possibility of one or two tautomeric equilibria: at pH close to 7 these compounds are not stable as dicationic species and they participate in the retention process as nitroso forms, which are not able to form ion pairs with alkylsulfonates. The dependences of the retention factor on the organic modifier content from mobile phase were linear. Two complementary theoretical models were used to explain the functional dependences for the retention data on the experimental parameters.

  8. Effects of Androctonus crassicauda (Olivier, 1807 (scorpiones: buthidae venom on rats: correlation among acetylcholinesterase activities and electrolytes levels

    O. Ozkan

    2007-01-01

    Full Text Available Scorpions can be considered living fossils because they have changed so little during the last 400 million years. They are venomous arthropods of the Arachnida class and regarded as relatives of spiders, ticks and mites. The aim of the present study was to evaluate the toxicity of Androctonus crassicauda (Olivier, 1807 venom and its effects on the acetylcholinesterase (AchE activity and on electrolytes levels in rats. Animals were divided into seven groups of five rats each. Test groups received 250µg/kg of venom solution while control group was treated with 200µl of physiological saline solution (PSS. Blood samples were collected from the animals on the 1st, 2nd 4th, 8th, 12th, and 24th hours after subcutaneous injection of venom. Animals were monitored for 24 hours. Androctonus crassicauda venom significantly reduced AchE activity on the 12th hour when compared with control group. A statistically negative correlation between Na+ and K+ (p<0.05 and a positive correlation between Na+ and CL- (p<0.001 ions levels were observed after the administration of A. crassiccauda venom to rats. We can conclude that the differences in the electrolytes levels are due to acute renal failure, since elimination of toxin occurs primarily via the kidney.

  9. Identification and Expression of Acetylcholinesterase in Octopus vulgaris Arm Development and Regeneration: a Conserved Role for ACHE?

    Fossati, Sara Maria; Candiani, Simona; Nödl, Marie-Therese; Maragliano, Luca; Pennuto, Maria; Domingues, Pedro; Benfenati, Fabio; Pestarino, Mario; Zullo, Letizia

    2015-08-01

    Acetylcholinesterase (ACHE) is a glycoprotein with a key role in terminating synaptic transmission in cholinergic neurons of both vertebrates and invertebrates. ACHE is also involved in the regulation of cell growth and morphogenesis during embryogenesis and regeneration acting through its non-cholinergic sites. The mollusk Octopus vulgaris provides a powerful model for investigating the mechanisms underlying tissue morphogenesis due to its high regenerative power. Here, we performed a comparative investigation of arm morphogenesis during adult arm regeneration and embryonic arm development which may provide insights on the conserved ACHE pathways. In this study, we cloned and characterized O. vulgaris ACHE, finding a single highly conserved ACHE hydrophobic variant, characterized by prototypical catalytic sites and a putative consensus region for a glycosylphosphatidylinositol (GPI)-anchor attachment at the COOH-terminus. We then show that its expression level is correlated to the stage of morphogenesis in both adult and embryonic arm. In particular, ACHE is localized in typical neuronal sites when adult-like arm morphology is established and in differentiating cell locations during the early stages of arm morphogenesis. This possibility is also supported by the presence in the ACHE sequence and model structure of both cholinergic and non-cholinergic sites. This study provides insights into ACHE conserved roles during processes of arm morphogenesis. In addition, our modeling study offers a solid basis for predicting the interaction of the ACHE domains with pharmacological blockers for in vivo investigations. We therefore suggest ACHE as a target for the regulation of tissue morphogenesis.

  10. Selection of insensitive acetylcholinesterase as a resistance mechanism in Aedes aegypti (Diptera: Culicidae) from Santiago de Cuba.

    Bisset, Juan; Rodríguez, María M; Fernández, Ditter

    2006-11-01

    A sample of Aedes aegypti (L.) (Diptera: Culicidae) from Santiago de Cuba, Cuba, with a high level of propoxur resistance compared with the reference susceptible Rockefeller strain (12.60 x at the 50% lethal concentration [LC50] and 18.08 at the 90% lethal concentration [LC90]), with a 4.3% frequency of insensitive acetylcholinesterase (AChE) frequency, was subjected to propoxur selection for 13 successive generations to increase the frequency of this resistance mechanism in Ae. aegypti. High resistance to propoxur was developed during this selection (41.73-fold), and the frequency of insensitive AChE mechanism was increased 13.25-fold. Other mechanisms (overproduced esterases, glutathione transferases, or monooxygenases) were not detected in the propoxur-selected strain. The selection of an insensitive AChE resistance mechanism in Ae. aegypti has important implications and will be a valuable resource for genetic studies and molecular characterization of the ace gene mutation(s) associated with insecticide resistance in Ae. aegypti.

  11. In vitro antioxidant properties, HIV-1 reverse transcriptase and acetylcholinesterase inhibitory effects of traditional herbal preparations sold in South Africa.

    Ndhlala, Ashwell R; Finnie, Jeffrey F; Van Staden, Johannes

    2010-10-08

    The antioxidant potentials for fourteen multipurpose traditional herbal preparations sold in South Africa were determined using the DPPH radical scavenging, ferric reducing power and β-carotene-linoleic acid model system, the anti-HIV-1 reverse transcriptase (RT) enzyme inhibitory effects using an ELISA kit and acetylcholinesterase (AChE) enzyme inhibition using the microtitre plate assay. Nine of the herbal mixtures (Umzimba omubi, Umuthi wekukhwehlela ne zilonda, Mvusa ukunzi, Umpatisa inkosi, Imbiza ephuzwato, Vusa umzimba, Supreme one hundred, Sejeso herbal mixture Ingwe® and Ingwe® special muti) exhibited higher antioxidant potentials, while only four (Imbiza ephuzwato, Ingwe® muthi mixture, Sejeso herbal mixture Ingwe® and African potato extract™ showed potent activity against the RT enzyme. Nine mixtures (Imbiza ephuzwato, Umpatisa inkosi, African potato extract™, Sejeso herbal mixture Ingwe®, Vusa umzimba; Ingwe® muthi mixture, Ibhubezi™, Lion izifozonke Ingwe® and Ingwe® special muti) showed AChE enzyme inhibitory activity greater than 50%. The observed activity exhibited by some of the herbal mixtures gives some credence to the manufacturers' claims and goes part of the way towards validating their use against certain conditions such as oxidative stress, HIV/AIDS proliferation and some mental conditions. It is however, desirable to carry out further studies to determine the effects of mixing plant species/parts in one mixture on the antioxidant potency as well as isolating active constituents from the herbal mixtures.

  12. Acetylcholinesterase activity in the terrestrial snail Xeropicta derbentina transplanted in apple orchards with different pesticide management strategies

    Mazzia, Christophe, E-mail: christophe.mazzia@univ-avignon.f [Universite d' Avignon et des Pays de Vaucluse, Laboratoire de Toxicologie Environnementale, UMR 406 UAPV/INRA, ' Abeilles et Environnement' , Domaine St Paul, Site Agroparc, 84914 Avignon Cedex 9 France (France); Capowiez, Yvan [INRA, UR 1115 ' Plante et Systemes Horticoles' , Domaine St Paul, Site Agroparc, 84914 Avignon Cedex 9 France (France); Sanchez-Hernandez, Juan C. [Laboratory of Ecotoxicology, Faculty of Environmental Science, University of Castilla-La Mancha, Avda. Carlos III s/n, 45071 Toledo (Spain); Koehler, Heinz-R. [Animal Physiological Ecology, Institute for Evolution and Ecology, University of Tuebingen, Konrad-Adenauer-Str. 20, D-72072 Tuebingen (Germany); Triebskorn, Rita [Animal Physiological Ecology, Institute for Evolution and Ecology, University of Tuebingen, Konrad-Adenauer-Str. 20, D-72072 Tuebingen (Germany); Steinbeis-Transfer Center for Ecotoxicology and Ecophysiology, Blumenstrasse 13, D-72108 Rottenburg (Germany); Rault, Magali [Universite d' Avignon et des Pays de Vaucluse, Laboratoire de Toxicologie Environnementale, UMR 406 UAPV/INRA, ' Abeilles et Environnement' , Domaine St Paul, Site Agroparc, 84914 Avignon Cedex 9 France (France)

    2011-01-15

    Apple orchards are highly manipulated crops in which large amounts of pesticides are used. Some of these pesticides lack target specificity and can cause adverse effects in non-target organisms. In order to evaluate the environmental risk of these products, the use of transplanted sentinel organisms avoids side-effects from past events and facilitate comparison of multiple sites in a short time. We released specimens of the terrestrial snail Xeropicta derbentina in each 5 of two kinds of apple orchards with either conventional or organic management strategies plus in a single abandoned orchard. After one month, individuals were retrieved in order to measure acetylcholinesterase (AChE) activity. Mean values of AChE activity were significantly reduced in all conventional apple orchards compared to the others. Results show that the measurement of biomarkers such as AChE inhibition in transplated X. derbentina could be useful in the environmental risk assessment of post-authorized pesticides. - Snails as sentinel species to evaluate insecticide impacts in apple orchards.

  13. Designing Second Generation Anti-Alzheimer Compounds as Inhibitors of Human Acetylcholinesterase: Computational Screening of Synthetic Molecules and Dietary Phytochemicals.

    Hafsa Amat-Ur-Rasool

    Full Text Available Alzheimer's disease (AD, a big cause of memory loss, is a progressive neurodegenerative disorder. The disease leads to irreversible loss of neurons that result in reduced level of acetylcholine neurotransmitter (ACh. The reduction of ACh level impairs brain functioning. One aspect of AD therapy is to maintain ACh level up to a safe limit, by blocking acetylcholinesterase (AChE, an enzyme that is naturally responsible for its degradation. This research presents an in-silico screening and designing of hAChE inhibitors as potential anti-Alzheimer drugs. Molecular docking results of the database retrieved (synthetic chemicals and dietary phytochemicals and self-drawn ligands were compared with Food and Drug Administration (FDA approved drugs against AD as controls. Furthermore, computational ADME studies were performed on the hits to assess their safety. Human AChE was found to be most approptiate target site as compared to commonly used Torpedo AChE. Among the tested dietry phytochemicals, berberastine, berberine, yohimbine, sanguinarine, elemol and naringenin are the worth mentioning phytochemicals as potential anti-Alzheimer drugs The synthetic leads were mostly dual binding site inhibitors with two binding subunits linked by a carbon chain i.e. second generation AD drugs. Fifteen new heterodimers were designed that were computationally more efficient inhibitors than previously reported compounds. Using computational methods, compounds present in online chemical databases can be screened to design more efficient and safer drugs against cognitive symptoms of AD.

  14. Acetylcholinesterases from the Disease Vectors Aedes aegypti and Anopheles gambiae: Functional Characterization and Comparisons with Vertebrate Orthologues.

    Engdahl, Cecilia; Knutsson, Sofie; Fredriksson, Sten-Åke; Linusson, Anna; Bucht, Göran; Ekström, Fredrik

    2015-01-01

    Mosquitoes of the Anopheles (An.) and Aedes (Ae.) genus are principal vectors of human diseases including malaria, dengue and yellow fever. Insecticide-based vector control is an established and important way of preventing transmission of such infections. Currently used insecticides can efficiently control mosquito populations, but there are growing concerns about emerging resistance, off-target toxicity and their ability to alter ecosystems. A potential target for the development of insecticides with reduced off-target toxicity is the cholinergic enzyme acetylcholinesterase (AChE). Herein, we report cloning, baculoviral expression and functional characterization of the wild-type AChE genes (ace-1) from An. gambiae and Ae. aegypti, including a naturally occurring insecticide-resistant (G119S) mutant of An. gambiae. Using enzymatic digestion and liquid chromatography-tandem mass spectrometry we found that the secreted proteins were post-translationally modified. The Michaelis-Menten constants and turnover numbers of the mosquito enzymes were lower than those of the orthologous AChEs from Mus musculus and Homo sapiens. We also found that the G119S substitution reduced the turnover rate of substrates and the potency of selected covalent inhibitors. Furthermore, non-covalent inhibitors were less sensitive to the G119S substitution and differentiate the mosquito enzymes from corresponding vertebrate enzymes. Our findings indicate that it may be possible to develop selective non-covalent inhibitors that effectively target both the wild-type and insecticide resistant mutants of mosquito AChE.

  15. A selective molecularly imprinted polymer for immobilization of acetylcholinesterase (AChE): an active enzyme targeted and efficient method.

    Demirci, Gökhan; Doğaç, Yasemin İspirli; Teke, Mustafa

    2015-11-01

    In the present study, we immobilized acetylcholinesterase (AChE) enzyme onto acetylcholine removed imprinted polymer and acetylcholine containing polymer. First, the polymers were produced with acetylcholine, substrate of AChE, by dispersion polymerization. Then, the enzyme was immobilized onto the polymers by using two different methods: In the first method (method A), acetylcholine was removed from the polymer, and then AChE was immobilized onto this polymer (acetylcholine removed imprinted polymer). In the second method (method B), AChE was immobilized onto acetylcholine containing polymer by affinity. In method A, enzyme-specific species (binding sites) occurred by removing acetylcholine from the polymer. The immobilized AChE reached 240% relative specific activity comparison with free AChE because the active enzyme molecules bounded onto the polymer. Transmission electron microscopy results were taken before and after immobilization of AChE for the assessment of morphological structure of polymer. Also, the experiments, which include optimum temperature (25-65 °C), optimum pH (3-10), thermal stability (4-70 °C), kinetic parameters, operational stability and reusability, were performed to determine the characteristic of the immobilized AChE.

  16. Intracerebroventricular D-galactose administration impairs memory and alters activity and expression of acetylcholinesterase in the rat.

    Rodrigues, André Felipe; Biasibetti, Helena; Zanotto, Bruna Stela; Sanches, Eduardo Farias; Pierozan, Paula; Schmitz, Felipe; Parisi, Mariana Migliorini; Barbé-Tuana, Florencia; Netto, Carlos Alexandre; Wyse, Angela T S

    2016-05-01

    Tissue accumulation of galactose is a hallmark in classical galactosemia. Cognitive deficit is a symptom of this disease which is poorly understood. The aim of this study was to investigate the effects of intracerebroventricular administration of galactose on memory (inhibitory avoidance and novel object recognition tasks) of adult rats. We also investigated the effects of galactose on acetylcholinesterase (AChE) activity, immunocontent and gene expression in hippocampus and cerebral cortex. Wistar rats received a single injection of galactose (4mM) or saline (control). For behavioral parameters, galactose was injected 1h or 24h previously to the testing. For biochemical assessment, animals were decapitated 1h, 3h or 24h after galactose or saline injection; hippocampus and cerebral cortex were dissected. Results showed that galactose impairs the memory formation process in aversive memory (inhibitory avoidance task) and recognition memory (novel object recognition task) in rats. The activity of AChE was increased, whereas the gene expression of this enzyme was decreased in hippocampus, but not in cerebral cortex. These findings suggest that these changes in AChE may, at least in part, to lead to memory impairment caused by galactose. Taken together, our results can help understand the etiopathology of classical galactosemia.

  17. Designing Second Generation Anti-Alzheimer Compounds as Inhibitors of Human Acetylcholinesterase: Computational Screening of Synthetic Molecules and Dietary Phytochemicals.

    Amat-Ur-Rasool, Hafsa; Ahmed, Mehboob

    2015-01-01

    Alzheimer's disease (AD), a big cause of memory loss, is a progressive neurodegenerative disorder. The disease leads to irreversible loss of neurons that result in reduced level of acetylcholine neurotransmitter (ACh). The reduction of ACh level impairs brain functioning. One aspect of AD therapy is to maintain ACh level up to a safe limit, by blocking acetylcholinesterase (AChE), an enzyme that is naturally responsible for its degradation. This research presents an in-silico screening and designing of hAChE inhibitors as potential anti-Alzheimer drugs. Molecular docking results of the database retrieved (synthetic chemicals and dietary phytochemicals) and self-drawn ligands were compared with Food and Drug Administration (FDA) approved drugs against AD as controls. Furthermore, computational ADME studies were performed on the hits to assess their safety. Human AChE was found to be most approptiate target site as compared to commonly used Torpedo AChE. Among the tested dietry phytochemicals, berberastine, berberine, yohimbine, sanguinarine, elemol and naringenin are the worth mentioning phytochemicals as potential anti-Alzheimer drugs The synthetic leads were mostly dual binding site inhibitors with two binding subunits linked by a carbon chain i.e. second generation AD drugs. Fifteen new heterodimers were designed that were computationally more efficient inhibitors than previously reported compounds. Using computational methods, compounds present in online chemical databases can be screened to design more efficient and safer drugs against cognitive symptoms of AD.

  18. Acetylcholinesterase Inhibitors (AChEI's for the treatment of visual hallucinations in schizophrenia: A review of the literature

    Patel Sachin S

    2010-09-01

    Full Text Available Abstract Background Visual hallucinations occur in various neurological diseases, but are most prominent in Lewy body dementia, Parkinson's disease and schizophrenia. The lifetime prevalence of visual hallucinations in patients with schizophrenia is much more common than conventionally thought and ranges from 24% to 72%. Cortical acetylcholine (ACh depletion has been associated with visual hallucinations; the level of depletion being related directly to the severity of the symptoms. Current understanding of neurobiological visual processing and research in diseases with reduced cholinergic function, suggests that AChEI's may prove beneficial in treating visual hallucinations. This offers the potential for targeted drug therapy of clinically symptomatic visual hallucinations in patients with schizophrenia using acetylcholinesterase inhibition. Methods A systematic review was carried out investigating the evidence for the effects of AChEI's in treating visual hallucinations in Schizophrenia. Results No evidence was found relating to the specific role of AChEI's in treating visual hallucinations in this patient group. Discussion Given the use of AChEI's in targeted, symptom specific treatment in other neuropsychiatric disorders, it is surprising to find no related literature in schizophrenia patients. The use of AChEI's in schizophrenia has investigated effects on cognition primarily with non cognitive effects measured more broadly. Conclusions We would suggest that more focused research into the effects of AChEI's on positive symptoms of schizophrenia, specifically visual hallucinations, is needed.

  19. Three-dimensional ordered macroporous (3DOM) composite for electrochemical study on acetylcholinesterase inhibition induced by endogenous neurotoxin.

    Teng, Yingqiao; Fu, Ying; Xu, Lili; Lin, Bin; Wang, Zhongchuan; Xu, Zhiai; Jin, Litong; Zhang, Wen

    2012-09-13

    In this paper, an electrochemical acetylcholinesterase (AChE) inhibition assay based on three-dimensional ordered macroporous (3DOM) composite was conducted. The 3DOM composite was first fabricated on the glassy carbon electrode by electropolymerization of aniline in the presence of ionic liquid (IL) on a sacrificial silica nanospheres template. After the silica nanospheres were etched, an IL-doped polyaniline (IL-PANI) film with 3DOM morphology was formed. Then, gold nanoparticles (AuNPs) were decorated on the IL-PANI film by electrodeposition. The immobilized AChE on the 3DOM composite displayed favorable affinity to substrate acetylthiocholine chloride (ATCh), and the 3DOM composite showed excellent electrocatalytic effect on thiocholine, the hydrolysis product of ATCh. The presence of IL and AuNPs could improve the sensitivity by accelerating the electron transfer. The designed AChE biosensor was successfully applied to evaluate the AChE inhibition induced by endogenous neurotoxin 1(R),2N-dimethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline [(R)-NMSal]. The results demonstrate that (R)-NMSal exerts a considerable effect on AChE activity, and the inhibition is reversible. The developed method offers a new approach for AChE inhibition assay, which is of great benefit in understanding the mechanism behind neurotoxin-induced neurodegenerative disorders.

  20. Pre-treatment with curcumin modulates acetylcholinesterase activity and proinflammatory cytokines in rats infected with Trypanosoma evansi.

    Wolkmer, Patrícia; Silva, Cássia B da; Paim, Francine C; Duarte, Marta M M F; Castro, Verônica; Palma, Heloisa E; França, Raqueli T; Felin, Diandra V; Siqueira, Lucas C; Lopes, Sonia T A; Schetinger, Maria Rosa C; Monteiro, Silvia G; Mazzanti, Cinthia M

    2013-04-01

    The potent activity against Trypanosomes and health beneficial effects of curcumin (Cur) has been demonstrated in various experimental models. In this study, we evaluated the in vivo effect of Cur as trypanocide and as potential anti-inflammatory agent, through the evaluation of immunomodulatory mechanisms in rats infected with Trypanosoma evansi. Daily oral Cur was administered at doses of 0, 20 or 60mg/kg as preventive treatment (30 and 15days pre infection) and as treatment (post infection). The treatment of the groups continued until the day of euthanasia. Fifteen days after inoculation, parasitemia, plasma proinflammatory cytokines (IFN-γ, TNF-α, IL-1, IL-6), anti-inflammatory cytokines (IL-10) and blood acetylcholinesterase activity (AChE) were analyzed. Pretreatment with Cur reduced parasitemia and lethality. Cur inhibited AChE activity and improved immunological response by cytokines proinflammatory, fundamental during T. evansi infection. We found that Cur is not so important as an antitrypanosomal activity but as immunomodulator agent. These findings reveal that the preventive use of Cur stimulates anti-inflammatory mechanisms, reducing an excessive inflammatory response.

  1. Different inhibition of acetylcholinesterase in selected parts of the rat brain following intoxication with VX and Russian VX.

    Hajek, Petr; Bajgar, Jiri; Slizova, Dasa; Krs, Otakar; Kuca, Kamil; Capek, Lukas; Fusek, Josef

    2009-01-01

    Differences between acetylcholinesterase (AChE) inhibition in the brain structures following VX and RVX exposure are not known as well as information on the possible correlation of biochemical and histochemical methods detecting AChE activity. Therefore, inhibition of AChE in different brain parts detected by histochemical and biochemical techniques was compared in rats intoxicated with VX and RVX. AChE activities in defined brain regions 30 min after treating rats with VX and Russian VX intramuscularly (1.0 x LD(50)) were determined by using biochemical and histochemical methods. AChE inhibition was less expressed for RVX, in comparison with VX. Frontal cortex and pontomedullar areas containing ncl. reticularis has been found as the most sensitive areas for the action of VX. For RVX, these structures were determined to be frontal cortex, dorsal septum, and hippocampus, respectively. Histochemical and biochemical results were in good correlation (R(xy) = 0.8337). Determination of AChE activity in defined brain structures was a more sensitive parameter for VX or RVX exposure than the determination of AChE activity in the whole-brain homogenate. This activity represents a "mean" of the activities in different structures. Thus, AChE activity is the main parameter investigated in studies searching for target sites following nerve-agent poisoning contributing to better understanding of toxicodynamics of nerve agents.

  2. Cognitive enhancing, anti-acetylcholinesterase, and antioxidant properties of Tagetes patula on scopolamine-induced amnesia in mice

    Prakash Ramakrishnan

    2015-01-01

    Full Text Available Background: Alzheimer′s disease is a progressive neurodegenerative disorder characterized by a gradual decline in memory associated with shrinkage of brain tissue and loss of neurons with a diminished level of the central cholinergic neurotransmitter acetylcholine. Objective: The present study was performed to examine the effect of ethanolic extract of Tagetes patula (EETP on cognitive impairment induced by scopolamine, a muscarinic antagonist, in mice. Materials and Methods: Rats were treated with EETP and donepezil for 15 successive days followed by treatment with scopolamine (1 mg/kg for 3 days. The changes in behavioral, biochemical, and neurotransmitters were assessed in rats. Cognitive functions were assessed using step-through latency on a passive avoidance apparatus and Morris water maze test. Antioxidants parametes such as superoxide dismutase (SOD, glutathione reductase (GR, lipid peroxidation (LPO, and nitrates were assessed. Neurotransmitters including acetylcholinesterase (AChE, dopamine (DA, and serotonin were also assessed, and neuronal damage was also analyzed. Results: Scopolamine-treated rats showed impaired learning and memory, increased activity of AChE, LPO and decreased levels of SOD, reduced glutathione, nitrates, serotonin, and DA. The EETP significantly reversed the scopolamine-induced cognitive impairment in mice was measured by the passive avoidance test. In addition, EETP decreased escape latency in the Morris water maze. In probe trail session, EETP increased the latency time in the target quadrant. Ex vivo EETP inhibited AChE activity in the mice brain. EETP treated mice significantly increased the SOD, GR, nitrates, DA, and serotonin levels, and decreased the level of LPO when compared with scopolamine-treated mice. Conclusion: These results indicate that EETP may exert anti-amnesic effect through both by anti-AChE and antioxidant mechanisms.

  3. Role of aqueous extract of Cynodon dactylon in prevention of carbofuran- induced oxidative stress and acetylcholinesterase inhibition in rat brain.

    Rai, D K; Sharma, R K; Rai, P K; Watal, G; Sharma, B

    2011-02-12

    The present study was designed to investigate the ameliorating effect of aqueous extract of C. dactylon on carbofuran induced oxidative stress (OS) and alterations in the activity of acetylcholinesterase (AChE) in the brain of rats. Vitamin C was used as a positive control. Wistar rats were administered with single sub-acute oral dose (1.6 mgkg-1 b.wt.) of carbofuran for 24 h. The OS parameters such as lipid peroxidation (LPO) and the activities of antioxidant enzymes including super oxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST), and that of AChE were studied in brain. Carbofuran treatment significantly increased the activities of SOD and CAT by 75 and 60%, respectively. It also induced the level of LPO by 113%. In contrast, the activities of GST and AChE were recorded to be diminished by 25 and 33%, respectively. Pretreatment of the rats with aqueous extract of C. dactylon (oral; 500mgkg-1) restored SOD activity completely but CAT activity only partially (7%). Carbofuran induced LPO was moderated by 95% in the brain of C. dactylon treated rats. The observed changes in OS parameters in C. dactylon treated group were comparable to that observed in vitamin C (200 mg-kg-1 b. wt.) treated group. Surprisingly, C. dactylon treatment significantly recovered the activity of AChE to a similar level as observed in the brain of control group. In contrast vitamin C treatment did not cause significant change in the activity of AChE in carbofuran treated group. There were no noticeable changes in the aforementioned study parameters in the brain of rats receiving C. dactylon and vitamin C, only. The results suggest that the study is extremely important in the context of development of new anticholinestesterase and antioxidant antidotes against carbofuran from C. dactylon.

  4. Transcriptional regulation of acetylcholinesterase-associated collagen ColQ in fast- and slow-twitch muscle fibers.

    Ting, Annie K L; Siow, Nina L; Kong, L W; Tsim, Karl W K

    2005-12-15

    The presence of a collagenous protein (ColQ) characterizes the collagen-tailed forms of acetylcholinesterase (AChE) and butyrylcholinesterase at vertebrate neuromuscular junctions, which is tethered in the synaptic basal lamina. ColQ subunits, differing mostly by their signal sequences, are encoded by transcripts ColQ-1 and ColQ-1a, which are differentially expressed in slow- and fast-twitch muscles in mammals, respectively. Both ColQ transcripts are derived from a single COLQ gene. Transcripts encoding ColQ increased during myogenic differentiation of C2C12 cells; the increase was in parallel with AChE catalytic subunit. Quantitative PCR analysis indicated that the increase during the myotube formation was due to the up regulation of ColQ-1 transcript instead of ColQ-1a. In order to reveal the regulatory mechanism of ColQ transcripts, two distinct promoters, pColQ-1 and pColQ-1a, were isolated from human COLQ gene. The ColQ promoters showed a muscle fiber type-specific expression pattern, and which was in line with the expression of endogenous transcript. After in vivo DNA transfection, pColQ-1 showed strong activity in slow-twitch muscle (e.g. soleus), while pColQ-1a was preferably expressed in fast-twitch muscle (e.g. tibialis). Mutation analysis of the ColQ promoters suggested that the muscle fiber type-specific expression pattern of ColQ transcripts was regulated by a slow upsteam regulatory element (SURE) and a fast intronic regulatory element (FIRE). These results explain the specific expression patterns of collagen-tailed AChE in slow and fast muscle fibers.

  5. The discovery of potential acetylcholinesterase inhibitors: A combination of pharmacophore modeling, virtual screening, and molecular docking studies

    Chuang Chih-Kuang

    2011-01-01

    Full Text Available Abstract Background Alzheimer's disease (AD is the most common cause of dementia characterized by progressive cognitive impairment in the elderly people. The most dramatic abnormalities are those of the cholinergic system. Acetylcholinesterase (AChE plays a key role in the regulation of the cholinergic system, and hence, inhibition of AChE has emerged as one of the most promising strategies for the treatment of AD. Methods In this study, we suggest a workflow for the identification and prioritization of potential compounds targeted against AChE. In order to elucidate the essential structural features for AChE, three-dimensional pharmacophore models were constructed using Discovery Studio 2.5.5 (DS 2.5.5 program based on a set of known AChE inhibitors. Results The best five-features pharmacophore model, which includes one hydrogen bond donor and four hydrophobic features, was generated from a training set of 62 compounds that yielded a correlation coefficient of R = 0.851 and a high prediction of fit values for a set of 26 test molecules with a correlation of R2 = 0.830. Our pharmacophore model also has a high Güner-Henry score and enrichment factor. Virtual screening performed on the NCI database obtained new inhibitors which have the potential to inhibit AChE and to protect neurons from Aβ toxicity. The hit compounds were subsequently subjected to molecular docking and evaluated by consensus scoring function, which resulted in 9 compounds with high pharmacophore fit values and predicted biological activity scores. These compounds showed interactions with important residues at the active site. Conclusions The information gained from this study may assist in the discovery of potential AChE inhibitors that are highly selective for its dual binding sites.

  6. In vitro and in vivo metabolism and inhibitory activities of vasicine, a potent acetylcholinesterase and butyrylcholinesterase inhibitor.

    Wei Liu

    Full Text Available Vasicine (VAS, a potential natural cholinesterase inhibitor, exhibited promising anticholinesterase activity in preclinical models and has been in development for treatment of Alzheimer's disease. This study systematically investigated the in vitro and in vivo metabolism of VAS in rat using ultra performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight mass spectrometry. A total of 72 metabolites were found based on a detailed analysis of their 1H- NMR and 13C NMR data. Six key metabolites were isolated from rat urine and elucidated as vasicinone, vasicinol, vasicinolone, 1,2,3,9-tetrahydropyrrolo [2,1-b] quinazolin-3-yl hydrogen sulfate, 9-oxo-1,2,3,9-tetrahydropyrrolo [2,1-b] quinazolin-3-yl hydrogen sulfate, and 1,2,3,9-tetrahydropyrrolo [2,1-b] quinazolin-3-β-D-glucuronide. The metabolic pathway of VAS in vivo and in vitro mainly involved monohydroxylation, dihydroxylation, trihydroxylation, oxidation, desaturation, sulfation, and glucuronidation. The main metabolic soft spots in the chemical structure of VAS were the 3-hydroxyl group and the C-9 site. All 72 metabolites were found in the urine sample, and 15, 25, 45, 18, and 11 metabolites were identified from rat feces, plasma, bile, rat liver microsomes, and rat primary hepatocyte incubations, respectively. Results indicated that renal clearance was the major excretion pathway of VAS. The acetylcholinesterase (AChE and butyrylcholinesterase (BChE inhibitory activities of VAS and its main metabolites were also evaluated. The results indicated that although most metabolites maintained potential inhibitory activity against AChE and BChE, but weaker than that of VAS. VAS undergoes metabolic inactivation process in vivo in respect to cholinesterase inhibitory activity.

  7. Chromogenic platform based on recombinant Drosophila melanogaster acetylcholinesterase for visible unidirectional assay of organophosphate and carbamate insecticide residues

    Han Zheng [Institute for Agri-food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, 1018 Jinqi Road, Shanghai 201403 (China); Chi Chensen [School of Life Science and Biotechnology, Bor Luh Food Safety Center, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Bai Bing; Liu Gang; Rao Qinxiong [Institute for Agri-food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, 1018 Jinqi Road, Shanghai 201403 (China); Peng Shaojie [Institute of Shanghai Food and Drug Supervision, 615 Liuzhou Road, Shanghai 200233 (China); Liu Hong [Shanghai Municipal Center for Disease Control and Prevention, 1380 Zhongshan West Road, Shanghai 200336 (China); Zhao Zhihui [Institute for Agri-food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, 1018 Jinqi Road, Shanghai 201403 (China); Zhang Dabing [School of Life Science and Biotechnology, Bor Luh Food Safety Center, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Wu Aibo, E-mail: wuaibo@saas.sh.cn [Institute for Agri-food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, 1018 Jinqi Road, Shanghai 201403 (China)

    2012-03-30

    Highlight: Black-Right-Pointing-Pointer A visible chromogenic platform for rapid analysis of OP and CM insecticide residues was developed. Black-Right-Pointing-Pointer The assay has the capabilities of both qualitative measurement and quantitative analysis. Black-Right-Pointing-Pointer The sensitivity, capabilities of resisting interferences and storage stability were desirable. Black-Right-Pointing-Pointer Matrix effects were acceptable and detection performance was satisfactory in real application. - Abstract: In this study we propose a chromogenic platform for rapid analysis of organophosphate (OP) and carbamate (CM) insecticide residues, based on recombinant Drosophila melanogaster acetylcholinesterase (R-DmAChE) as enzyme and indoxyl acetate as substrate. The visible chromogenic strip had the advantages identical to those of commonly used lateral flow assays (LFAs) with utmost simplicity in sample loading and result observation. After optimization, depending on the color intensity (CI) values, the well-established assay has the capabilities of both qualitative measurement via naked eyes and quantitative analysis by colorimetric reader with the desirable IC{sub 50} values against the tested six insecticides (0.06 {mu}g mL{sup -1} of carbofuran, 0.28 {mu}g mL{sup -1} of methomyl, 0.03 {mu}g mL{sup -1} of dichlorvos, 31.6 {mu}g mL{sup -1} of methamidophos, 2.0 {mu}g mL{sup -1} of monocrotophos, 6.3 {mu}g mL{sup -1} of omethoate). Acceptable matrix effects and satisfactory detection performance were confirmed by in-parallel LC-MS/MS analysis in different vegetable varieties at various spiked levels of 10{sup -3} to 10{sup 1} {mu}g g{sup -1}. Overall, the testified suitability and applicability of this novel platform meet the requirements for practical use in food safety management and environmental monitoring, especially in the developing world.

  8. Altered acetylcholinesterase levels in the spinal cord anterior horn and dorsal root ganglion following sciatic nerve ischemia

    Zhenjun Yang; Pei Wang; Songhe Yang; Jingfeng Xue

    2009-01-01

    BACKGROUND: Peripheral nerve ischemia has been shown to result in ischemic fiber degeneration and axoplasmic transport disturbance. However, the effect on acetylcholinesterase (AChE) expression in relevant cells following sciatic nerve ischemia remains unclear. OBJECTIVE: To observe AChE concentration changes following peripheral nerve ischemia. DESIGN, TIME AND SETTING: The present comparative observation, neuroanatomical experiment was performed at the Central Laboratory Animal of Chengde Medical College between 2006 and 2007. MATERIALS: A total of 20 healthy, adult, Wistar rats were randomized into two groups (n = 10): 8-day ischemia and 14-day ischemia. METHODS: Ischemia injury was induced in the unilateral sciatic nerve (experimental side) through ligation of the common iliac artery. The contralateral side received no intervention, and served as the control side. Rats in the 8-day ischemia and 14-day ischemia groups were allowed to survive for 8 and 14 days, respectively. MAIN OUTCOME MEASURES: The L5 lumbar spinal cord and the L5 dorsal root ganglion were removed from both sides and sectioned utilizing a Leica vibrating slicer. AChE cellular expression was detected using Karnovsky-Root, and the number of AChE-positive cells and average gray value were analyzed using a MiVnt image analysis system. RESULTS: In the 8-day ischemia group, AChE-positive cell numbers were significantly less in the dorsal root ganglion and spinal cord anterior horn of the experimental side, but the average gray value was significantly greater, compared with the control side (P < 0.05). These changes were more significant in the 14-day ischemia group than in the 8-day ischemia group (P < 0.01). CONCLUSION: Peripheral nerve ischemia leads to decreased AChE expression in the associated cells in a time-dependent manner.

  9. Acetylcholinesterase is associated with apoptosis in β cells and contributes to insulin-dependent diabetes mellitus pathogenesis

    Bao Zhang; QiOuyang; Bo Zhang; Lu Lu; Xuejun Zhang; Lei Yang; Luyang Yu; Bo Lin; Yanan Hou; Jun Wu; Qin Huang; Yifan Han; Lihe Guo

    2012-01-01

    Acetylcholinesterase (AChE) expression is pivotal during apoptosis.Indeed,AChE inhibitors partially protect cells from apoptosis.Insulin-dependent diabetes mellitus (IDDM)is characterized in part by pancreatic β-cell apoptosis.Here,we investigated the role of AChE in the development of IDDM and analyzed protective effects of AChE inhibitors.Multiple low-dose streptozotocin (MLD-STZ) administration resulted in IDDM in a mouse model.Western blot analysis, cytochemical staining, and immunofluorescence staining were used to detect AChE expression in MIN6 cells,primary β cells,and apoptotic pancreatic β cells of MLD-STZ-treated mice.AChE inhibitors were administered intraperitoneally to the MLD-STZ mice for 30 days.Blood glucose,plasma insulin,and creatine levels were measured,and glucose tolerance tests were performed.The effects of AChE inhibitors on MIN6 cells were also evaluated.AChE expression was induced in the apoptotic MIN6 cells and primary β cells in vitro and pancreatic islets in vivo when treated with STZ.Induction and progressive accumulation of AChE in the pancreatic islets were associated with apoptotic β cells during IDDM development.The administration of AChE inhibitors effectively decreased hyperglycemia and incidence of diabetes,and restored plasma insulin levels and plasma creatine clearance in the MLD-STZ mice.AChE inhibitors partially protected MIN6 cells from the damage caused by STZ treatment.Induction and accumulation of AChE in pancreatic islets and the protective effects of AChE inhibitors on the onset and development of IDDM indicate a close relationship between AChE and IDDM.

  10. Neuroprotective effects of pretreatment with quercetin as assessed by acetylcholinesterase assay and behavioral testing in poloxamer-407 induced hyperlipidemic rats.

    Braun, Josiane B S; Ruchel, Jader B; Adefegha, Stephen A; Coelho, Ana Paula V; Trelles, Kelly B; Signor, Cristiane; Rubin, Maribel A; Oliveira, Juliana S; Dornelles, Guilherme L; de Andrade, Cinthia M; Castilhos, Lívia G; Leal, Daniela B R

    2017-04-01

    Hyperlipidemia is a group of disorders characterized by excessive lipids in the bloodstream. It is associated with the incidence of cardiovascular diseases and recognized as the most important factor underlying the occurrence of atherosclerosis. This study was conducted to investigate whether pretreatment with quercetin can protect against possible memory impairment and deterioration of the cholinergic system in hyperlipidemic rats. Animals were divided into ten groups (n=7): saline/control, saline/quercetin 5mg/kg, saline/quercetin 25mg/kg, saline/quercetin 50mg/kg, saline/simvastatin (0.04mg/kg), hyperlipidemia, hyperlipidemia/quercetin 5mg/kg, hyperlipidemia/quercetin 25mg/kg, hyperlipidemia/quercetin 50mg/kg and hyperlipidemia/simvastatin. The animals were pretreated with quercetin by oral gavage for a period of 30days and hyperlipidemia was subsequently induced by intraperitoneal administration of a single dose of 500mg/kg of poloxamer-407. Simvastatin was administered after the induction of hyperlipidemia. The results demonstrated that hyperlipidemic rats had memory impairment compared with the saline control group (P<0.001). However, pretreatment with quercetin and simvastatin treatment attenuated the damage caused by hyperlipidemia compared with the hyperlipidemic group (P<0.05). Acetylcholinesterase (AChE) activity in the cerebral hippocampus was significantly (P<0.001) reduced in the hyperlipidemic group compared with the control saline group. Pretreatment with quercetin and simvastatin treatment in the hyperlipidemic groups significantly (P<0.05) increased AChE activity compared with the hyperlipidemic group. Our results thus suggest that quercetin may prevent memory impairment, alter lipid metabolism, and modulate AChE activity in an experimental model of hyperlipidemia.

  11. Hypothyroidism Enhanced Ectonucleotidases and Acetylcholinesterase Activities in Rat Synaptosomes can be Prevented by the Naturally Occurring Polyphenol Quercetin.

    Baldissarelli, Jucimara; Santi, Adriana; Schmatz, Roberta; Abdalla, Fátima Husein; Cardoso, Andréia Machado; Martins, Caroline Curry; Dias, Glaecir R Mundstock; Calgaroto, Nicéia Spanholi; Pelinson, Luana Paula; Reichert, Karine Paula; Loro, Vania Lucia; Morsch, Vera Maria Melchiors; Schetinger, Maria Rosa Chitolina

    2017-01-01

    Thyroid hormones have an influence on the functioning of the central nervous system. Furthermore, the cholinergic and purinergic systems also are extensively involved in brain function. In this context, quercetin is a polyphenol with antioxidant and neuroprotective properties. This study investigated the effects of (MMI)-induced hypothyroidism on the NTPDase, 5'-nucleotidase, adenosine deaminase (ADA), and acetylcholinesterase (AChE) activities in synaptosomes of rats and whether the quercetin can prevent it. MMI at a concentration of 20 mg/100 mL was administered for 90 days in the drinking water. The animals were divided into six groups: control/water (CT/W), control/quercetin 10 mg/kg, control/quercetin 25 mg/kg, methimazole/water (MMI/W), methimazole/quercetin 10 mg/kg (MMI/Q10), and methimazole/quercetin 25 mg/kg (MMI/Q25). On the 30th day, hormonal dosing was performed to confirm hypothyroidism, and the animals were subsequently treated with 10 or 25 mg/kg quercetin for 60 days. NTPDase activity was not altered in the MMI/W group. However, treatment with quercetin decreased ATP and ADP hydrolysis in the MMI/Q10 and MMI/Q25 groups. 5'-nucleotidase activity increased in the MMI/W group, but treatments with 10 or 25 mg/kg quercetin decreased 5'-nucleotidase activity. ADA activity decreased in the CT/25 and MMI/Q25 groups. Furthermore, AChE activity was reduced in all groups with hypothyroidism. In vitro tests also demonstrated that quercetin per se decreased NTPDase, 5'-nucleotidase, and AChE activities. This study demonstrated changes in the 5'-nucleotidase and AChE activities indicating that purinergic and cholinergic neurotransmission are altered in this condition. In addition, quercetin can alter these parameters and may be a promising natural compound with important neuroprotective actions in hypothyroidism.

  12. Neuroprotective effects of quercetin on memory and anxiogenic-like behavior in diabetic rats: Role of ectonucleotidases and acetylcholinesterase activities.

    Maciel, Roberto M; Carvalho, Fabiano B; Olabiyi, Ayodeji A; Schmatz, Roberta; Gutierres, Jessié M; Stefanello, Naiara; Zanini, Daniela; Rosa, Michelle M; Andrade, Cinthia M; Rubin, Maribel A; Schetinger, Maria Rosa; Morsch, Vera Maria; Danesi, Cristiane C; Lopes, Sonia T A

    2016-12-01

    The present study investigated the protective effect of quercetin (Querc) on memory, anxiety-like behavior and impairment of ectonucleotidases and acetylcholinesterase (AChE) activities in brain of streptozotocin-induced diabetic rats (STZ-diabetes). The type 1 diabetes mellitus was induced by an intraperitoneal injection of 70mg/kg of streptozotocin (STZ), diluted in 0.1M sodium-citrate buffer (pH 4.5). Querc was dissolved in 25% ethanol and administered by gavage at the doses of 5, 25 and 50mg/kg once a day during 40days. The animals were distributed in eight groups of ten animals as follows: vehicle, Querc 5mg/kg, Querc 25mg/kg, Querc 50mg/kg, diabetes, diabetes plus Querc 5mg/kg, diabetes plus Querc 25mg/kg and diabetes plus Querc 50mg/kg. Querc was able to prevent the impairment of memory and the anxiogenic-like behavior induced by STZ-diabetes. In addition, Querc prevents the decrease in the NTPDase and increase in the adenosine deaminase (ADA) activities in SN from cerebral cortex of STZ-diabetes. STZ-diabetes increased the AChE activity in SN from cerebral cortex and hippocampus. Querc 50mg/kg was more effective to prevent the increase in AChE activity in the brain of STZ-diabetes. Querc also prevented an increase in the malondialdehyde levels in all the brain structures. In conclusion, the present findings showed that Querc could prevent the impairment of the enzymes that regulate the purinergic and cholinergic extracellular signaling and improve the memory and anxiety-like behavior induced by STZ-diabetes.

  13. Effects of metals on blood oxidative stress biomarkers and acetylcholinesterase activity in dice snakes (Natrix tessellata from Serbia

    Gavrić Jelena P.

    2015-01-01

    Full Text Available The effects of waterborne metals in water on the activities of blood copper-zinc superoxide dismutase (CuZnSOD, catalase (CAT, glutathione peroxidase (GSH-Px, glutathione reductase (GR, glutathione-S-transferase (GST, and acetylcholinesterase (AChE, and on the concentrations of total glutathione (GSH and lipid peroxides (TBARS in the blood of dice snakes (Natrix tessellata caught in Obedska Bara, Sebia (control area, with snakes caught in Pančevački Rit, a contaminated area in Serbia were examined. The activities of CAT, GSH-Px, GR and AChE, and the concentration of TBARS were significantly decreased, while GST activity and GSH concentration were significantly increased in snakes from the contaminated area compared to specimens from the control area. Significantly increased concentrations of Al, As, B, Ba, Ca, Cu, Fe, K, Li, Mn, Na, Ni and Zn in the water at the contaminated area as compared to control area were detected. The metals Ag, Bi, Cd, Co, Hg, In and Tl were not observed in any of the localities. Cr, Mo and Pb were not detected at the control area but were observed at the contaminated area. The concentrations of Sr were similar at both sites. The concentration of Mg was 2-fold higher at the control site than at the contaminated area. The obtained results show that most of the investigated blood biomarkers correlate with concentrations of metals present in the environment. These findings suggest that dice snakes are sensitive bioindicator species for monitoring the effects of increased metal concentrations in the environment. [Projekat Ministarstva nauke Republike Srbije, br. 173041 i br. 173043

  14. Cerebrospinal fluid (CSF 25-hydroxyvitamin D concentration and CSF acetylcholinesterase activity are reduced in patients with Alzheimer's disease.

    Per Johansson

    Full Text Available BACKGROUND: Little is known of vitamin D concentration in cerebrospinal fluid (CSF in Alzheimer's disease (AD and its relation with CSF acetylcholinesterase (AChE activity, a marker of cholinergic function. METHODS: A cross-sectional study of 52 consecutive patients under primary evaluation of cognitive impairment and 17 healthy controls. The patients had AD dementia or mild cognitive impairment (MCI diagnosed with AD dementia upon follow-up (n = 28, other dementias (n = 12, and stable MCI (SMCI, n = 12. We determined serum and CSF concentrations of calcium, parathyroid hormone (PTH, 25-hydroxyvitamin D (25OHD, and CSF activities of AChE and butyrylcholinesterase (BuChE. FINDINGS: CSF 25OHD level was reduced in AD patients (P < 0.05, and CSF AChE activity was decreased both in patients with AD (P < 0.05 and other dementias (P < 0.01 compared to healthy controls. None of the measured variables differed between BuChE K-variant genotypes whereas the participants that were homozygous in terms of the apolipoprotein E (APOE ε4 allele had decreased CSF AChE activity compared to subjects lacking the APOE ε4 allele (P = 0.01. In AD patients (n=28, CSF AChE activity correlated positively with CSF levels of total tau (T-tau (r = 0.44, P < 0.05 and phosphorylated tau protein (P-tau (r = 0.50, P < 0.01, but CSF activities of AChE or BuChE did not correlate with serum or CSF levels of 25OHD. CONCLUSIONS: In this pilot study, both CSF 25OHD level and CSF AChE activity were reduced in AD patients. However, the lack of correlations between 25OHD levels and CSF activities of AChE or BuChE might suggest different mechanisms of action, which could have implications for treatment trials.

  15. Electrochemical Assay of Effects of Organophosphate Poisoning on Acetylcholinesterase from Pheretima via2,6-Dimethyl-p-benzoquinone

    WU Wu-ai; LI Jun; GAO Bao-ping; GUO Man-dong

    2012-01-01

    Electroanalytical techniques could be a reliable and promising alternative to classical and sophisticatcd methods because of their simplicity(small and portable),easy use,the ability to deliver fast response with high sensitivity and selectivity.A square wave voltammetric method was developed for the assessment of organophosphorus(OPs) compound impact on acetylcholinesterase(AChE) of Pheretima with 2,6-dimethyl-p-benzoquinone(2,6-DMBQ) as a redox indicator.The substrate of acetylthiocholine is hydrolyzed by AChE and the produced thiocholine reacts with 2,6-DMBQ to give an obvious shift of electrochemical signal.The reduction peak of 2,6-DMBQ is located at around -0.18 V which is far away from the oxidation potential of possible interference components often present in biosample.The decreased rate of reduction current was related with the activity of AChE.The inhibition of parathion-methyl on AChE was assessed.The inhibiton rate of OPs on AChE activity increased quickly during the first 10min inhibition,and after that the value of inhibition rate approached to be constant.AChE lost almost 29.3% of activity after 10 min incubation with 1 μg/mL parathion-methyl and 67.5% of activity with 10 μg/mL parathion-methyl,while the activity that corresponds to 40 μg/mL parathion-methyl was nearly completely inhibited(94.9%).Compared to cyclic voltammetry and amperometry,Square wave voltammetry(SWV) method is a high sensitive electroanalysis with fast scan-rate(only several seconds for one signal value) which is useful to prevent the electrodes from possible fouling or passivation.This method can be employed to assess the inhibition of organophosphate on AChE and investigate OPs impact on environmental animals.

  16. Correlation of acetylcholinesterase activity in the brain and blood of wistar rats acutely infected with Trypanosoma congolense

    Habila N; Inuwa HM; Aimola IA; Lasisi OI; Chechet DG; Okafor IA

    2012-01-01

    Objective: To investigate the neurotransmitter enzyme Acetylcholinesterase (AChE) activity in the brain and blood of rats infected with Trypanosoma congolense (T. congo). Methods: Presence and degree of parasitemia was determined daily for each rat by the rapid matching method. AChE activity was determined by preparing a reaction mixture of brain homogenate and whole blood with 5, 5-dithiobisnitrobenzioc acid (DTNB or Ellman’s reagent) and Acetylthiocholine (ATC). The increase in absorbance was recorded at 436 nm over 10 min at 2 min intervals. Trypanosome species identification (before inoculation and on day 10 post infection) was done by Polymerase chain reaction using specific primers. Results: The AChE activity in the brain and blood decreased significantly as compared with the uninfected control. The AChE activity dropped to 0.32 from 2.20 μmol ACTC min-1mg protein-1 in the brain and 4.57 to 0.76 μmol ACTC min-1mg protein-1 in the blood. The animals treated with Diminaveto at 3.5 mg/kg/d were observed to have recovered significantly from parasitemia and were able to regain AChE activity in the blood but not in the brain as compared to the control groups. We also observed, that progressive parasitemia resulted to alterations in PCV, Hb, RBC, WBC, neurophils, total protein, lymphocytes, monocytes and eosinophil in acute infections of T. congo. Polymerase chain reaction (PCR) of infected blood before inoculation and on day 10 post infection revealed 600 bp on agarose gel electrophoresis. Conclusions: This finding suggest that decrease in AChE activity increases acetylcholine concentration in the synaptic cleft resulting to neurological failures in impulse transfer in T. congo infection rats.

  17. Structural changes of phenylalanine 338 and histidine 447 revealed by the crystal structures of tabun-inhibited murine acetylcholinesterase.

    Ekström, Fredrik; Akfur, Christine; Tunemalm, Anna-Karin; Lundberg, Susanne

    2006-01-10

    Organophosphorus compounds (OPs) interfere with the catalytic mechanism of acetylcholinesterase (AChE) by rapidly phosphorylating the catalytic serine residue. The inhibited enzyme can at least partly be reactivated with nucleophilic reactivators such as oximes. The covalently attached OP conjugate may undergo further intramolecular dealkylation or deamidation reactions, a process termed "aging" that results in an enzyme considered completely resistant to reactivation. Of particular interest is the inhibition and aging reaction of the OP compound tabun since tabun conjugates display an extraordinary resistance toward most reactivators of today. To investigate the structural basis for this resistance, we determined the crystal structures of Mus musculus AChE (mAChE) inhibited by tabun prior to and after the aging reaction. The nonaged tabun conjugate induces a structural change of the side chain of His447 that uncouples the catalytic triad and positions the imidazole ring of His447 in a conformation where it may form a hydrogen bond to a water molecule. Moreover, an unexpected displacement of the side chain of Phe338 narrows the active site gorge. In the crystal structure of the aged tabun conjugate, the side chains of His447 and Phe338 are reversed to the conformation found in the apo structure of mAChE. A hydrogen bond between the imidazole ring of His447 and the ethoxy oxygen of the aged tabun conjugate stabilizes the side chain of His447. The displacement of the side chain of Phe338 into the active site gorge of the nonaged tabun conjugate may interfere with the accessibility of reactivators and thereby contribute to the high resistance of tabun conjugates toward reactivation.

  18. Inhibition of acetylcholinesterase in CSF versus brain assessed by 11C-PMP PET in AD patients treated with galantamine.

    Darreh-Shori, T; Kadir, A; Almkvist, O; Grut, M; Wall, A; Blomquist, G; Eriksson, B; Långström, B; Nordberg, A

    2008-02-01

    The relationship between acetylcholinesterase (AChE) activity in the CSF and brain of patients with Alzheimer's disease (AD) was investigated in 18 mild AD patients following galantamine treatment. The first 3 months of the study had a randomized double-blind placebo-controlled design, during which 12 patients received galantamine (16-24 mg/day) and six patients placebo. This was followed by 9 months galantamine treatment in all patients. Activities and protein levels of both the "read-through" AChE (AChE-R) and the synaptic (AChE-S) variants in CSF were assessed in parallel together with the regional brain AChE activity by (11)C-PMP and PET. The AChE-S inhibition was 30-36% in CSF, which correlated well with the in vivo AChE inhibition in the brain. No significant AChE inhibition was observed in the placebo group. The increased level of the AChE-R protein was 16% higher than that of AChE-S. Both the AChE inhibition and the increased level of AChE-R protein positively correlated with the patient's performance in cognitive tests associated with visuospatial ability and attention. In conclusion, AChE levels in CSF closely mirror in vivo brain AChE levels prior to and after treatment with the cholinesterase inhibitors. A positive cognitive response seems to dependent on the AChE inhibition level, which is balanced by an increased protein level of the AChE-R variant in the patients.

  19. Acetylcholinesterase inhibition in cognition-relevant brain areas of mice treated with a nootropic Amazonian herbal (Marapuama).

    Figueiró, M; Ilha, J; Pochmann, D; Porciúncula, L O; Xavier, L L; Achaval, M; Nunes, D S; Elisabetsky, E

    2010-10-01

    The goal of acetylcholinesterase inhibitors (AChEIs) used to treat Alzheimer's patients is an improvement in cholinergic transmission. While currently available AChEIs have limited success, a huge impediment to the development of newer ones is access to the relevant brain areas. Promnesic, anti-amnesic and AChEI properties were identified in a standardized ethanol extract from Ptychopetalum olacoides (POEE), a medicinal plant favored by the elderly in Amazon communities. The purpose of this study was to provide conclusive evidence that orally given POEE induces AChE inhibition in brain areas relevant to cognition. Histochemistry experiments confirmed that the anticholinesterase compound(s) present in POEE are orally bioavailable, inducing meaningful AChE inhibition in the hippocampus CA1 (∼33%) and CA3 (∼20%), and striatum (∼17%). Ellman's colorimetric analysis revealed that G1 and G4 AChE isoforms activities were markedly inhibited (66 and 72%, respectively) in hippocampus and frontal cortex (50 and 63%, respectively), while G4 appeared to be selectively inhibited (72%) in the striatum. Western blotting showed that POEE did not induce significant changes in the AChE immunocontent suggesting that its synthesis is not extensively modified. This study provides definitive proof of meaningful anticholinesterase activity compatible with the observed promnesic and anti-amnesic effects of POEE in mice, reaffirming the potential of this extract for treating neurodegenerative conditions where a hypofunctioning cholinergic neurotransmission is prominent. Adequate assessment of the safety and efficacy of this extract and/or its isolated active compound(s) are warranted.

  20. Identification of Potential Herbal Inhibitor of Acetylcholinesterase Associated Alzheimer’s Disorders Using Molecular Docking and Molecular Dynamics Simulation

    Chandrabhan Seniya

    2014-01-01

    Full Text Available Cholinesterase inhibitors (ChE-Is are the standard for the therapy of AD associated disorders and are the only class of approved drugs by the Food and Drug Administration (FDA. Additionally, acetylcholinesterase (AChE is the target for many Alzheimer’s dementia drugs which block the function of AChE but have some side effects. Therefore, in this paper, an attempt was made to elucidate cholinesterase inhibition potential of secondary metabolite from Cannabis plant which has negligible or no side effect. Molecular docking of 500 herbal compounds, against AChE, was performed using Autodock 4.2 as per the standard protocols. Molecular dynamics simulations have also been carried out to check stability of binding complex in water for 1000 ps. Our molecular docking and simulation have predicted high binding affinity of secondary metabolite (C28H34N2O6 to AChE. Further, molecular dynamics simulations for 1000 ps suggest that ligand interaction with the residues Asp72, Tyr70-121-334, and Phe288 of AChE, all of which fall under active site/subsite or binding pocket, might be critical for the inhibitory activity of AChE. This approach might be helpful to understand the selectivity of the given drug molecule in the treatment of Alzheimer's disease. The study provides evidence for consideration of C28H34N2O6 as a valuable small ligand molecule in treatment and prevention of AD associated disorders and further in vitro and in vivo investigations may prove its therapeutic potential.

  1. Brain acetylcholinesterase, malondialdehyde and reduced glutathione as biomarkers of continuous exposure of tench, Tinca tinca, to carbofuran or deltamethrin.

    Hernández-Moreno, D; Soler, F; Míguez, M P; Pérez-López, M

    2010-10-01

    In this study, the chronic effect of the insecticides carbofuran and deltamethrin on acetylcholinesterase (AChE) activity and malondialdehyde (MDA) and reduced glutathione (GSH) levels were examined in the brain of tench. Both pesticides were evaluated in two separate experiments, and animals were exposed in a continuous flow-system to three different concentrations of carbofuran (0, 10 and 100 microg/L) and deltamethrin (0, 0.0039 and 0.039 microg/L) for 60 days. After that period, animals were kept into pesticide-free water for other 30 days. In all cases, animals were sampled every 10 days all along the experience. AChE activity was significantly inhibited in fish exposed to 100 microg/L of carbofuran, during the first 30 days of exposition, returning to basal levels after this initial period. With respect to deltamethrin exposure, AChE activity was not significantly affected. When considering MDA levels, significant changes could only be detected during the recovery period for both pesticides, with a maximum of induction at 70 and 80 days, respectively associated to the highest dose of carbofuran and deltamethrin. Similarly, GSH levels varied all along the experience, with a maximum of significant increase at day 80 of exposition to the highest dose of both pesticides. This study shows that changes in AChE brain activity in tench can be used as a biomarker of early pesticide exposition in environmental monitoring programs, whereas MDA and GSH levels could be more associated to long-term expositions. The above results confirm and broaden former observations, suggesting that more investigations are needed before these biochemical parameters can be used as biomarkers.

  2. Therapeutic potential of Garcinia kola with reference to the restoration of inhibited acetylcholinesterase activities in induced Clarias gariepinus

    T.O. Ikpesu

    2014-12-01

    Full Text Available This study was conducted to assess the antidotal prospect of Garcinia kola seeds extract in restoring the activity of inhibited Acetylcholinesterase. This was done by inducing Clarias gariepinus with the enzyme inhibitor (glyphosate pesticide formulation. The fish divided into six groups were exposed different treatments; the pesticide alone, the G. kola seed extract alone and different mixture of the pesticide and G. kola seeds extract. AChE activities in the brain, liver and serum of the fish were measured in the experimental and control fish on day −7, 14, 21 and 28th by the colorimetric method. The enzyme was significantly (p < 0.05 inhibited in the glyphosate formulation test alone and in group IV treatment (0.16 mg/L glyphosate formulation with 150 mg/L of extract. The inhibition percentages of AChE ranged for the brain, liver and serum between 40.7–59.4%, 50–57% and 27.5–51.3%, respectively. The AChE activities were however, recovered in G. kola seeds extract treated aquaria, and were dose, time dependent and organ specific. Modifications of this enzyme may leads to increased perspiration, increased salivation, tearing, blurred vision, abdominal cramping, diarrhea, and if severe enough, death from respiratory depression. This investigation had revealed the therapeutic significance of G. kola seeds extract, by stabilizing the enzyme activity in the investigated fish. Further investigation is required to measure the concentrations of acetylcholine at cholinergic synaptic junction in fish and mammals induced with ant-cholinesterase agent and the possibility of its restoration using G. kola seeds.

  3. The application of HPLC with on-line coupled UV/MS-biochemical detection for isolation of an acetylcholinesterase inhibitor from narcissus 'Sir Winston Churchill'.

    Ingkaninan, K; Hazekamp, A; de Best, C M; Irth, H; Tjaden, U R; van der Heijden, R; van der Greef, J; Verpoorte, R

    2000-06-01

    An HPLC with on-line coupled UV/MS-biochemical detection method for acetylcholinesterase (AChE) inhibitors in natural sources has been developed. The potential of this method is shown by the isolation of a new AChE inhibitor from the alcoholic extract of Narcissus 'Sir Winston Churchill'. Combining a prefractionation technique using centrifugal partition chromatography with the on-line HPLC-UV/MS-biochemical detection resulted in the isolation of the active compound that was identified as ungiminorine. This alkaloid shows a mild inhibitory effect on AChE.

  4. Sesquiterpenes produced by endophytic fungus Phomopsis cassiae with antifungal and acetylcholinesterase inhibition activities; Sesquiterpenos produzidos pelo fungo endofitico Phomopsis cassiae com atividade antifungica e inibidora de acetilcolinesterase

    Zanardi, Lisineia M.; Bolzani, Vanderlan da S.; Cavalheiro, Alberto J.; Silva, Dulce H. Siqueira; Trevisan, Henrique C.; Araujo, Angela R. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica; Silva, Geraldo H. [Universidade Federal de Sergipe (UFS), Aracaju, SE (Brazil). Centro de Ciencias Exatas e Tecnologia; Teles, Helder L. [Universidade Federal do Mato Grosso (UFMT), Rondonopolis, MT (Brazil). Dept. de Ciencias Biologicas; Young, Maria Claudia M., E-mail: araujoar@iq.unesp.br [Instituto de Botanica, Sao Paulo, SP (Brazil). Seccao de Fisiologia e Bioquimica de Plantas

    2012-07-01

    Two new diastereoisomeric cadinanes sesquiterpenes 3,9-dihydroxycalamenene (1-2), along with the known 3-hydroxycalamen-8-one (3) and aristelegone-A (4), were isolated from ethyl acetate extract of Phomopsis cassiae, an endophytic fungus in Cassia spectabilis. Their structures, including relative stereochemistry, were determined on the basis of detailed interpretation of 2D NMR spectra and comparison with related known compounds. Compounds 1-4 displayed antifungal activity against the phytopathogenic fungi Cladosporium cladosporioides and C. sphaerospermum, as well as inhibition of acetylcholinesterase. (author)

  5. Phytoestrogens genistein and daidzin enhance the acetylcholinesterase activity of the rat pheochromocytoma cell line PC12 by binding to the estrogen receptor

    Isoda, Hiroko; Talorete, Terence P. N.; Kimura, Momoko; Maekawa, Takaaki; Inamori, Yuhei; Nakajima, Nobuyoshi; Seki, Humitake

    2002-01-01

    Some compounds derived from plants have been known to possess estrogenic properties and can thus alter the physiology of higher organisms. Genistein and daidzin are examples of these phytoestrogens, which have recently been the subject of extensive research. In this study, genistein and daidzin were found to enhance the acetylcholinesterase (AChE) activity of the rat neuronal cell line PC12 at concentrations as low as 0.08 μM by binding to the estrogen receptor (ER). Results have shown that t...

  6. Effect of propofol on the reactivity of acetylcholinesterase, N-methyl-D-aspartate receptors, and gamma-aminobutyric acid receptors in the hippocampus of aged rats after chronic cerebral ischemia

    Gang Chen; Jiangbei Cao; Weidong Mi

    2011-01-01

    We induced ischemic brain injury in aging rats to examine the effects of varying doses of propofol on hippocampal activities of acetylcholinesterase, N-methyl-D-aspartate receptors, and γ-aminobutyric acid receptors. Propofol exhibited no obvious impact on acetylcholinesterase activity, but directly activated the γ-aminobutyric acid receptor. The neuroprotective function of propofol on the hippocampus of aging rats following cerebral ischemic injury may be related to altered activities of γ-aminobutyric acid receptors and N-methyl-D-aspartate receptors.

  7. Biological evaluation of synthetic α,β-unsaturated carbonyl based cyclohexanone derivatives as neuroprotective novel inhibitors of acetylcholinesterase, butyrylcholinesterase and amyloid-β aggregation.

    Zha, Gao-Feng; Zhang, Cheng-Pan; Qin, Hua-Li; Jantan, Ibrahim; Sher, Muhammad; Amjad, Muhammad Wahab; Hussain, Muhammad Ajaz; Hussain, Zahid; Bukhari, Syed Nasir Abbas

    2016-05-15

    A series of new α,β-unsaturated carbonyl-based cyclohexanone derivatives was synthesized by simple condensation method and all compounds were characterized by using various spectroscopic techniques. New compounds were evaluated for their effects on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). These compounds were also screened for in vitro cytotoxicity and for inhibitory activity for self-induced Aβ1-42 aggregation. The effect of these compounds against amyloid β-induced cytotoxicity was also investigated. The findings of in vitro experiment revealed that most of these compounds exhibited potent inhibitory activity against AChE and self-induced Aβ1-42 aggregation. The compound 3o exhibited best AChE (IC50=0.037μM) inhibitory potential. Furthermore, compound 3o disassembled the Aβ fibrils produced by self-induced Aβ aggregation by 76.6%. Compounds containing N-methyl-4-piperidone linker, showed high acetylcholinesterase and self-induced Aβ aggregation inhibitory activities as compared to reference drug donepezil. The pre-treatment of cells with synthetic compounds protected them against Aβ-induced cell death by up to 92%. Collectively, these findings suggest that some compounds from this series have potential to be promising multifunctional agents for AD treatment and our study suggest the cyclohexanone derivatives as promising new inhibitors for AChE and BuChE, potentially useful to treat neurodegenerative diseases.

  8. Virtual screening using MTiOpenScreen and PyRx 0,8 revealed ZINC95486216 as a human acetylcholinesterase inhibitor candidate

    Sulistyo Dwi K., P.; Arindra Trisna, W.; Vindri Catur P., W.; Wijayanti, Erna; Ichsan, Mochammad

    2016-03-01

    One of the efforts to prevent Alzheimer's disease becomes more severe is by inhibiting the activity of Human acetylcholinesterase enzyme (PDB ID: 4BDT). In this study, virtual screening againts 885 natural compounds from AfroDB has been done using MTIOpenScreen and this step has been successful in identifying ZINC15121024 (-12,9) and ZINC95486216 (-12,7) as the top rank compounds. This data then strengthened by the results of second docking step using Autodock software that has been integrated in PyRx 0.8 software. From this stage, ZINC95486216 (-11,3 kcal/mol) is a compound with the most negative binding affinity compared with four Alzheimer's drugs that have been officially used to date including Rivastigmine (-6,3 Kcal/mol), Donepenzil (-7.9 kcal/mol), Galantamine (-8.4 kcal/mol), and Huprine W (-7.3 kcal/mol). In addition, based on the results of the 2D and 3D visualization using LigPlus and PyMol softwares, respectively, known that the five compounds above are equally capable of binding to several amino acids (Trp 286, Phe295, and Tyr341) located in the active site of Human Acetylcholinesterase enzyme.

  9. Synthesis, characterization, acetylcholinesterase inhibition, molecular modeling and antioxidant activities of some novel Schiff bases derived from 1-(2-ketoiminoethyl)piperazines.

    Salga, Saleh M; Ali, Hapipah M; Abdullah, Mahmood A; Abdelwahab, Siddig I; Wai, Lam Kok; Buckle, Michael J C; Sukumaran, Sri Devi; Hadi, A Hamid A

    2011-11-07

    Some novel Schiff bases derived from 1-(2-ketoiminoethyl)piperazines were synthesized and characterized by mass spectroscopy, FTIR, UV-Visible, 1H and 13C-NMR. The compounds were tested for inhibitory activities on human acetylcholinesterase (hAChE), antioxidant activities, acute oral toxicity and further studied by molecular modeling techniques. The study identified the compound (DHP) to have the highest activity among the series in hAChE inhibition and DPPH assay while the compound LP revealed the highest activity in the FRAP assay. The hAChE inhibitory activity of DHP is comparable with that of propidium, a known AChE inhibitor. This high activity of DHP was checked by molecular modeling which showed that DHP could not be considered as a bivalent ligand due to its incapability to occupy the esteratic site (ES) region of the 3D crystal structure of hAChE. The antioxidant study unveiled varying results in 1,1-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. This indicates mechanistic variations of the compounds in the two assays. The potential therapeutic applications and safety of these compounds were suggested for use as human acetylcholinesterase inhibitors and antioxidants.

  10. Syntheses of coumarin-tacrine hybrids as dual-site acetylcholinesterase inhibitors and their activity against butylcholinesterase, Aβ aggregation, and β-secretase.

    Sun, Qi; Peng, Da-Yong; Yang, Sheng-Gang; Zhu, Xiao-Lei; Yang, Wen-Chao; Yang, Guang-Fu

    2014-09-01

    Exploring small-molecule acetylcholinesterase (AChE) inhibitors to slow the breakdown of acetylcholine (Ach) represents the mainstream direction for Alzheimer's disease (AD) therapy. As the first acetylcholinesterase inhibitor approved for the clinical treatment of AD, tacrine has been widely used as a pharmacophore to design hybrid compounds in order to combine its potent AChE inhibition with other multi-target profiles. In present study, a series of novel tacrine-coumarin hybrids were designed, synthesized and evaluated as potent dual-site AChE inhibitors. Moreover, compound 1g was identified as the most potent candidate with about 2-fold higher potency (Ki=16.7nM) against human AChE and about 2-fold lower potency (Ki=16.1nM) against BChE than tacrine (Ki=35.7nM for AChE, Ki=8.7nM for BChE), respectively. In addition, some of the tacrine-coumarin hybrids showed simultaneous inhibitory effects against both Aβ aggregation and β-secretase. We therefore conclude that tacrine-coumarin hybrid is an interesting multifunctional lead for the AD drug discovery.

  11. In vitro anti-acetylcholinesterase activity of an aqueous extract of Unicaria tomentosa and in silico study of its active constituents

    Chowdhury, Suman; Shivani; Kumar, Suresh

    2016-01-01

    Depletion of acetylcholine in the central nervous system (CNS) is responsible for memory loss and cognition deficit. Enzyme acetylcholinesterase (AChE) is responsible for destruction of acetylcholine (Ach) in the brain. Many herbal plant extracts have been investigated for their potential use in the treatment of Alzheimer’s disease (AD) by inhibiting AChE and upregulating the levels of Ach. The current study investigated the anti-acetylcholinesterase (AChE) activity of an aqueous extract of Unicaria tomentosa bark which has not been reported so far in the literature. The in vitro study of an aqueous extract of U. tomentosa showed maximum inhibition of 76.2±0.002 % at 0.4mg/ml of final concentration with an IC50 = 0.112 mg/ml. The mechanism of inhibition was elucidated by kinetic study which showed mixed type of inhibition, this might be due to the presence of various phytoconstituents such as oxindole alkaloids present in an aqueous extract. Based on molecular structure of phytoconstituents obtained from U. tomentosa known from the relevant literature, in-silico molecular docking study was performed against AChE protein to validate the results. PMID:28149044

  12. Effects of immature cashew nut-shell liquid (Anacardium occidentale) against oxidative damage in Saccharomyces cerevisiae and inhibition of acetylcholinesterase activity.

    De Lima, S G; Feitosa, C M; Citó, A M G L; Moita Neto, J M; Lopes, J A D; Leite, A S; Brito, M C; Dantas, S M M; Cavalcante, A A C Melo

    2008-09-09

    The cashew tree (Anacardium occidentale) represents one of the major cheapest sources of non-isoprenoid phenolic lipids, which have a variety of biological properties: they can act as molluscicides, insecticides, fungicides, have anti-termite properties, have medicinal applications, and demonstrate antioxidant activity in vitro. Immature cashew nut-shell liquid (iCNSL) is a unique natural source of unsaturated long-chain phenols. Their use has stimulated much research in order to prepare drug analogues for application in several fields. The objective of the present study was to determine whether iCNSL has antioxidant properties when used in strains of the yeast Saccharomyces cerevisiae and to measure the inhibitory activity of acetylcholinesterase. The constituents were identified using thin-layer chromatography, gas chromatography-mass spectrometry, Fourier transform infrared spectroscopy, and (1)H and (13)C nuclear magnetic resonance. The iCNSL contains anacardic acid, cardanol, cardol, and 2-methyl cardol. Immature cashew nut oil contains triacylglycerols, fatty acids, alkyl-substituted phenols, and cholesterol. The main constituents of the free fatty acids are palmitic (C(16:0)) and oleic acid (C(18:1)). iCNSL has excellent protective activities in strains of S. cerevisiae against oxidative damage induced by hydrogen peroxide and inhibits acetylcholinesterase activity. iCNSL may have an important role in protecting DNA against damage induced by reactive oxygen species, as well as hydrogen peroxide, generated by intra- and extracellular mechanisms.

  13. Multiple Mutations on the Second Acetylcholinesterase Gene Associated With Dimethoate Resistance in the Melon Aphid, Aphis gossypii (Hemiptera: Aphididae).

    Lokeshwari, D; Krishna Kumar, N K; Manjunatha, H

    2016-04-01

    The melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is an important cosmopolitan and extremely polyphagous species capable of causing direct and indirect damage to various crops. Insecticide resistance in melon aphids is of particular concern. To determine the basis of resistance, organophosphate (OP)-resistant strains of A. gossypii were obtained by continuous selection with dimethoate in the laboratory, and resistance mechanisms were investigated along with susceptible strains. Three resistant strains LKR-1, LKR-2, and LKR-3 exhibiting 270-, 243-, and 210-fold resistance obtained after 30 generations of selection with dimethoate, respectively, were utilized in this study. The role of acetylcholinesterase (AChE), a target enzyme for OPs and carbamates (CMs), was investigated. AChE enzyme assay revealed that there was no significant change in the activities of AChE in resistant and susceptible strains. However, AChE inhibitory assay showed that 50% of the enzyme activity in resistant strains was inhibited at significantly higher concentration of dimethoate (131.87, 158.65, and 99.29 µmolL(−1)) as compared with susceptible strains (1.75 and 2.01 µmolL(−1)), indicating AChE insensitivity owing to altered AChE. Molecular diagnostic tool polymerase chain reaction-restriction fragment length polymorphism revealed the existence of two consistent non-synonymous point mutations, single-nucleotide polymorphism, viz., A302S (equivalent to A201 in Torpedo californica Ayres) and S431F (equivalent to F331 in T. californica), in the AChE gene Ace2 of resistant strains. Further, cloning and sequencing of a partial fragment of Ace2 (897 bp) gene from susceptible and resistant strains revealed an additional novel mutation G221A in resistant strains, LKR-1 and LKR-2. Susceptible Ace2 genes shared 99.6 and 98.9% identity at the nucleic acid and amino acid levels with resistant ones, respectively. Functional analysis of these point mutations was assessed by in

  14. The non-competitive acetylcholinesterase inhibitor APS12-2 is a potent antagonist of skeletal muscle nicotinic acetylcholine receptors

    Grandič, Marjana [Institute of Physiology, Pharmacology and Toxicology, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, SI-1000 Ljubljana (Slovenia); Aráoz, Romulo; Molgó, Jordi [CNRS, Institut de Neurobiologie Alfred Fessard, FRC 2118, Laboratoire de Neurobiologie et Développement, UPR 3294, F-91198 Gif-sur-Yvette Cedex (France); Turk, Tom; Sepčić, Kristina [Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, SI-1000 Ljubljana (Slovenia); Benoit, Evelyne [CNRS, Institut de Neurobiologie Alfred Fessard, FRC 2118, Laboratoire de Neurobiologie et Développement, UPR 3294, F-91198 Gif-sur-Yvette Cedex (France); Frangež, Robert, E-mail: robert.frangez@vf.uni-lj.si [Institute of Physiology, Pharmacology and Toxicology, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, SI-1000 Ljubljana (Slovenia)

    2012-12-01

    APS12-2, a non-competitive acetylcholinesterase inhibitor, is one of the synthetic analogs of polymeric alkylpyridinium salts (poly-APS) isolated from the marine sponge Reniera sarai. In the present work the effects of APS12-2 were studied on isolated mouse phrenic nerve–hemidiaphragm muscle preparations, using twitch tension measurements and electrophysiological recordings. APS12-2 in a concentration-dependent manner blocked nerve-evoked isometric muscle contraction (IC{sub 50} = 0.74 μM), without affecting directly-elicited twitch tension up to 2.72 μM. The compound (0.007–3.40 μM) decreased the amplitude of miniature endplate potentials until a complete block by concentrations higher than 0.68 μM, without affecting their frequency. Full size endplate potentials, recorded after blocking voltage-gated muscle sodium channels, were inhibited by APS12-2 in a concentration-dependent manner (IC{sub 50} = 0.36 μM) without significant change in the resting membrane potential of the muscle fibers up to 3.40 μM. The compound also blocked acetylcholine-evoked inward currents in Xenopus oocytes in which Torpedo (α1{sub 2}β1γδ) muscle-type nicotinic acetylcholine receptors (nAChRs) have been incorporated (IC{sub 50} = 0.0005 μM), indicating a higher affinity of the compound for Torpedo (α1{sub 2}β1γδ) than for the mouse (α1{sub 2}β1γε) nAChR. Our data show for the first time that APS12-2 blocks neuromuscular transmission by a non-depolarizing mechanism through an action on postsynaptic nAChRs of the skeletal neuromuscular junction. -- Highlights: ► APS12-2 produces concentration-dependent inhibition of nerve-evoked muscle contraction in vitro. ► APS12-2 blocks MEPPs and EPPs at the neuromuscular junction. APS12-2 blocks ACh-activated current in Xenopus oocytes incorporated with Torpedo nAChRs.

  15. Rapid eye movement (REM sleep deprivation reduces rat frontal cortex acetylcholinesterase (EC 3.1.1.7 activity

    Camarini R.

    1997-01-01

    Full Text Available Rapid eye movement (REM sleep deprivation induces several behavioral changes. Among these, a decrease in yawning behavior produced by low doses of cholinergic agonists is observed which indicates a change in brain cholinergic neurotransmission after REM sleep deprivation. Acetylcholinesterase (Achase controls acetylcholine (Ach availability in the synaptic cleft. Therefore, altered Achase activity may lead to a change in Ach availability at the receptor level which, in turn, may result in modification of cholinergic neurotransmission. To determine if REM sleep deprivation would change the activity of Achase, male Wistar rats, 3 months old, weighing 250-300 g, were deprived of REM sleep for 96 h by the flower-pot technique (N = 12. Two additional groups, a home-cage control (N = 6 and a large platform control (N = 6, were also used. Achase was measured in the frontal cortex using two different methods to obtain the enzyme activity. One method consisted of the obtention of total (900 g supernatant, membrane-bound (100,000 g pellet and soluble (100,000 g supernatant Achase, and the other method consisted of the obtention of a fraction (40,000 g pellet enriched in synaptic membrane-bound enzyme. In both preparations, REM sleep deprivation induced a significant decrease in rat frontal cortex Achase activity when compared to both home-cage and large platform controls. REM sleep deprivation induced a significant decrease of 16% in the membrane-bound Achase activity (nmol thiocholine formed min-1 mg protein-1 in the 100,000 g pellet enzyme preparation (home-cage group 152.1 ± 5.7, large platform group 152.7 ± 24.9 and REM sleep-deprived group 127.9 ± 13.8. There was no difference in the soluble enzyme activity. REM sleep deprivation also induced a significant decrease of 20% in the enriched synaptic membrane-bound Achase activity (home-cage group 126.4 ± 21.5, large platform group 127.8 ± 20.4, REM sleep-deprived group 102.8 ± 14.2. Our results

  16. A Novel Acetylcholinesterase Biosensor: Core-Shell Magnetic Nanoparticles Incorporating a Conjugated Polymer for the Detection of Organophosphorus Pesticides.

    Dzudzevic Cancar, Hurija; Soylemez, Saniye; Akpinar, Yeliz; Kesik, Melis; Göker, Seza; Gunbas, Gorkem; Volkan, Murvet; Toppare, Levent

    2016-03-01

    To construct a sensing interface, in the present work, a conjugated polymer and core-shell magnetic nanoparticle containing biosensor was constructed for the pesticide analysis. The monomer 4,7-di(furan-2-yl)benzo[c][1,2,5]thiadiazole (FBThF) and core-shell magnetic nanoparticles were designed and synthesized for fabrication of the biosensing device. The magnetic nanoparticles were first treated with silica and then modified using carboxyl groups, which enabled binding of the biomolecules covalently. For the construction of the proposed sensor a two-step procedure was performed. First, the poly(FBThF) was electrochemically generated on the electrode surface. Then, carboxyl group modified magnetic nanoparticles (f-MNPs) and acetylcholinesterase (AChE), the model enzyme, were co-immobilized on the polymer-coated surface. Thereby, a robust and novel surface, conjugated polymer bearing magnetic nanoparticles with pendant carboxyl groups, was constructed, which was characterized using Fourier transform infrared spectrometer, cyclic voltammetry, scanning electron microscopy, and contact angle measurements. This novel architecture was then applied as an immobilization platform to detect pesticides. To the best of our knowledge, a sensor design that combines both conjugated polymer and magnetic nanoparticles was attempted for the first time, and this approach resulted in improved biosensor characteristics. Hence, this approach opens a new perspective in the field of enzyme immobilization and sensing applications. Paraoxon and trichlorfon were selected as the model toxicants. To obtain best biosensor performance, optimization studies were performed. Under optimized conditions, the biosensor in concern revealed a rapid response (5 s), a low detection limit (6.66 × 10(-3) mM), and high sensitivity (45.01 μA mM(-1) cm(-2)). The KM(app) value of poly(FBThF)/f-MNPs/AChE were determined as 0.73 mM. Furthermore, there was no considerable activity loss for 10 d for poly

  17. Combined effects of chlorpyriphos, copper and temperature on acetylcholinesterase activity and toxicokinetics of the chemicals in the earthworm Eisenia fetida.

    Bednarska, Agnieszka J; Choczyński, Maciej; Laskowski, Ryszard; Walczak, Marcin

    2017-01-01

    In polluted environments organisms are commonly exposed to a combination of chemicals with different modes of action, and their effects can be additionally modified by natural abiotic conditions. One possible mechanism for interactions in mixtures is via toxicokinetics, as chemicals may alter the uptake, distribution, biotransformation and/or elimination of each other, and all these processes can be affected by temperature. In this study, the effect of temperature (T) on the toxicokinetics of copper (Cu) and chlorpyriphos (CHP), applied either singly or in binary mixtures, was studied in the earthworm Eisenia fetida. The experiments were conducted at 10 or 20 °C and the earthworms were exposed to environmentally realistic concentrations of Cu and/or CHP for 16 d, followed by a depuration period of 4 d in uncontaminated soil. The earthworms were sampled for body Cu and/or CHP concentrations and acetylcholinesterase (AChE) activity measurements. The CHP degradation rate in the soil was substantially higher at 20 °C and in soil treated with Cu. The significant (p < 0.05) inhibition of AChE activity in the earthworms exposed to CHP was found. The effect of Cu was significant only at p < 0.1. No synergistic effect of the parallel CHP and Cu exposure was found. Four days after transferring the earthworms to uncontaminated soil, the AChE activity recovered to the level observed in control animals. The temperature effect on the toxicokinetic parameters was more pronounced for CHP than for Cu. In the case of CHP, the assimilation rate constant (kA) was significantly higher at 20 °C than at 10 °C, both in CHP-only and CHP + Cu treatments. A similar trend was found for the elimination rate constant (kE), but the difference was statistically significant only for non-Cu treatments. In the case of Cu, the general trend of higher kA and kE at 20 °C and in the absence of CHP was observed.

  18. Acetylcholinesterase and Acetylcholine Receptor

    1989-01-30

    placing the ester group at th- estera - tic site. K. values for AcCh and DMBAc are similar, indicating no substantial coulombic effe,-t, and the...V. P. (1950) Biochim. BioDhys. Acta 4, 543-558. 2. "Studies on Cholinesterase. VII. The Active Surface of Acetylcholine Esterase Derived from Effects...L., Chang, H. W., and Chen-, Y. T. (1972) J. Biol. Chem. 247, 1555-1565. 42. "Rapid and Complete Purification of Acetylcholin- esterases of Electric

  19. Detoxification of Acetylcholinesterase Inhibitors.

    1987-02-19

    herbicides and as other biological control agents. Although some of the modern organophosphates are thought to be among the safest of all chenical...organophosphates including parathion and amino-parathion. The esterase hydrolyzes parathion to diethylthio- phosphate and p- nitrophenol . Several of these parathion...in the presence of water will ’esult in the 0-18 exclusively associated with p- nitrophenol , whereas mechanism A or B will leave the label associated

  20. Differential Effects of Acetylcholinesterase Inhibitors on Clinical Responses and Cerebral Blood Flow Changes in Patients with Alzheimer's Disease: A 12-Month, Randomized, and Open-Label Trial

    Soichiro Shimizu

    2015-04-01

    Full Text Available Background/Aims: The present study evaluated the differences in treatment outcomes and brain perfusion changes among 3 types of acetylcholinesterase inhibitors (AchEIs, i.e. donepezil, rivastigmine, and galantamine. Methods: This was a prospective, longitudinal, randomized, open-label, 3-arm (donepezil, rivastigmine, or galantamine, parallel-group, 12-month clinical trial carried out in 55 patients with AD. Results: At 6 months, the results of the Mini-Mental State Examination (MMSE and the Trail Making Test (TMT-Part A showed an improvement versus baseline in the donepezil treatment group. All groups showed a significant increase in regional cerebral blood flow (rCBF, mainly in the frontal lobe. Significant rCBF reduction was observed in the temporal lobe and cingulate gyrus in all 3 groups. Conclusion: AchEI treatment prevents the progression of cognitive impairment and increases the relative rCBF in the frontal lobe.

  1. C- and O-glycosyl flavonoids in Sanguinello and Tarocco blood orange (Citrus sinensis (L.) Osbeck) juice: Identification and influence on antioxidant properties and acetylcholinesterase activity.

    Barreca, Davide; Gattuso, Giuseppe; Laganà, Giuseppina; Leuzzi, Ugo; Bellocco, Ersilia

    2016-04-01

    Sanguinello and Tarocco are the blood orange (Citrus sinensis (L.) Osbeck) cultivars most diffused worldwide. Reversed phase liquid chromatography coupled with MS-MS analysis showed that these two varieties have a similar chromatographic pattern, characterised by the presence of C- and O-glycosyl flavonoids. Of the two, Sanguinello was found to be far richer in flavonoids than Tarocco. In the juices, twelve individual components were identified for the first time, namely, four C-glycosyl flavones (lucenin-2, vicenin-2, stellarin-2, lucenin-2 4'-methyl ether and scoparin), three flavonol derivatives (quercetin-3-O-(2-rhamnosyl)-rutinoside, quercetin-3-O-hexoside, quercetin 3-hydroxy-3-methylglutaryl-glycoside), an O-triglycosyl flavanone (narirutin 4'-O-glucoside) and a flavone O-glycosides (chrysoeriol 7-O-neoesperidoside). Moreover, the influence of the identified C- and O-glycosyl flavonoids on the antioxidant and acetylcholinesterase activity of these juices has been evaluated.

  2. A conformational restriction approach to the development of dual inhibitors of acetylcholinesterase and serotonin transporter as potential agents for Alzheimer's disease.

    Toda, Narihiro; Tago, Keiko; Marumoto, Shinji; Takami, Kazuko; Ori, Mayuko; Yamada, Naho; Koyama, Kazuo; Naruto, Shunji; Abe, Kazumi; Yamazaki, Reina; Hara, Takao; Aoyagi, Atsushi; Abe, Yasuyuki; Kaneko, Tsugio; Kogen, Hiroshi

    2003-10-01

    Alzheimer's disease (AD) has been treated with acetylcholinesterase (AChE) inhibitors such as donepezil. However, the clinical usefulness of AChE inhibitors is limited mainly due to their adverse peripheral effects. Depression seen in AD patients has been treated with serotonin transporter (SERT) inhibitors. We considered that combining SERT and AChE inhibition could improve the clinical usefulness of AChE inhibitors. In a previous paper, we found a potential dual inhibitor, 1, of AChE (IC50=101 nM) and SERT (IC50=42 nM), but its AChE inhibition activity was less than donepezil (IC50=10 nM). Here, we report the conformationally restricted (R)-18a considerably enhanced inhibitory activity against AChE (IC50=14 nM) and SERT (IC50=6 nM).

  3. Design, synthesis and structure-activity relationships of dual inhibitors of acetylcholinesterase and serotonin transporter as potential agents for Alzheimer's disease.

    Toda, Narihiro; Tago, Keiko; Marumoto, Shinji; Takami, Kazuko; Ori, Mayuko; Yamada, Naho; Koyama, Kazuo; Naruto, Shunji; Abe, Kazumi; Yamazaki, Reina; Hara, Takao; Aoyagi, Atsushi; Abe, Yasuyuki; Kaneko, Tsugio; Kogen, Hiroshi

    2003-05-01

    We have designed and synthesized a dual inhibitor of acetylcholinesterase (AChE) and serotonin transporter (SERT) as a novel class of treatment drugs for Alzheimer's disease on the basis of a hypothetical model of the AChE active site. Dual inhibitions of AChE and SERT would bring about greater therapeutic effects than AChE inhibition alone and avoid adverse peripheral effects caused by excessive AChE inhibition. Compound (S)-6j exhibited potent inhibitory activities against AChE (IC(50)=101 nM) and SERT (IC(50)=42 nM). Furthermore, (S)-6j showed inhibitory activities of both AChE and SERT in mice brain following oral administration.

  4. Synthesis and Acetylcholinesterase Inhibitory Evaluation of 4-(1,3-Dioxoisoindolin-2-yl)-N-Phenyl Benzamide Derivatives as Potential Anti-Alzheimer Agents

    Mohammadi-Farani, Ahmad; Soltani Darbandi, Samira; Aliabadi, Alireza

    2016-01-01

    Alzheimer᾽s disease is characterized by cognitive deficits, impaired long-term potentiation of learning and memory. A progressive reduction in cholinergic neurons in some areas of the brain such as cortex and hippocampus is related to the deficits in memory and cognitive function in Alzheimer’s disease (AD). In the current project a new series of phthalimide derivatives were synthesized. Phthalic anhydride was reacted with 4-aminobenzoic acid in the presence of triethylamine under reflux condition. Then, the obtained acidic derivative was utilized for preparation of final compounds via an amidation reaction through a carbodiimde coupling reaction. Anti-acetylcholinesterase activity of synthesized derivatives was assessed by Ellman᾽s test. Compound 4g in this series exhibited the highest inhibitory potency (IC50 = 1.1 ± 0.25 µM) compared to donepezil (IC50 = 0.41 ± 0.12 µM) as reference drug. PMID:27980565

  5. Development of fluorescent array based on sol-gel/chitosan encapsulated acetylcholinesterase and pH sensitive oxazol-5-one derivative.

    Ozturk, Gulsiye; Feller, Karl-Heinz; Dornbusch, Kay; Timur, Suna; Alp, Serap; Ergun, Yavuz

    2011-01-01

    A highly sensitive fluorescent enzyme array for quantitative acetylcholine detection is developed. The enzyme array has been constructed by spotting of pH sensitive fluorophore 2-phenyl-4-[4-(1,4,7,10-tetraoxa-13-azacycloopentadecyl)benzylidene]oxazol-5-one and acetylcholinesterase doped in tetraethoxysilane/chitosan matrix via a microarrayer. The constructed tetraethoxysilane/chitosan network provided a microenvironment in which the enzyme molecule was active biologically. The optimal operational conditions for the array developed were investigated. The response of the developed biosensor array to acetylcholine was highly reproducible (RSD = 3.27%, n = 6). A good linearity was observed for acetylcholine in the concentrations up to 1 × 10(-8) M, with a detection limit of 0.27 × 10(-8) M.

  6. Zephycandidine A, the First Naturally Occurring Imidazo[1,2-f]phenanthridine Alkaloid from Zephyranthes candida, Exhibits Significant Anti-tumor and Anti-acetylcholinesterase Activities

    Zhan, Guanqun; Qu, Xiaolan; Liu, Junjun; Tong, Qingyi; Zhou, Junfei; Sun, Bin; Yao, Guangmin

    2016-09-01

    Zephycandidine A (1), the first naturally occurring imidazo[1,2-f]phenanthridine alkaloid, was isolated from Zephyranthes candida (Amaryllidaceae). The structure of 1 was elucidated by spectroscopic analyses and NMR calculation, and a plausible biogenetic pathway for zephycandidine A (1) was proposed. Zephycandidine A (1) exhibited significant cytotoxicity against five cancer cell lines with IC50 values ranging from 1.98 to 7.03 μM with selectivity indices as high as 10 when compared to the normal Beas-2B cell. Further studies suggested that zephycandidine A (1) induces apoptosis in leukemia cells by the activation of caspase-3, upregulation of Bax, downregulation of Bcl-2, and degradation of PARP expression. In addition, zephycandidine A (1) showed acetylcholinesterase (AChE) inhibitory activity, and the docking studies of zephycandidine A (1) and galanthamine (2) with AChE revealed that interactions with W286 and Y337 are necessary.

  7. Bioaccumulation of PCB-153 and effects on molecular biomarkers acetylcholinesterase, glutathione-S-transferase and glutathione peroxidase in Mytilus galloprovincialis mussels.

    Vidal-Liñán, Leticia; Bellas, Juan; Soriano, José Antonio; Concha-Graña, Estefanía; Muniategui, Soledad; Beiras, Ricardo

    2016-07-01

    In this study, PCB-153 bioaccumulation kinetics and concentration-response experiments were performed employing wild Mytilus galloprovincialis mussels. In addition, the activity of three enzymatic biomarkers: glutathione S-transferase (GST), glutathione peroxidase (GPx) and acetylcholinesterase (AChE), were measured in the mussel gills. The experimental data fitted well to an asymptotic accumulation model with a high bioconcentration factor (BCF) of 9324 L kg(-1) and a very limited depuration capacity, described by a low excretion rate coefficient (Kd = 0.083 d(-1)). This study reports by first time in mussels significant inhibition of GST activity and significant induction of GPx activity as a result of exposure to dissolved PCB-153. In contrast, AChE activity was unaffected at all concentrations and exposure times tested. The effects on both enzymes are time-dependent, which stresses the difficulties inherent to the use of these biomarkers in chemical pollution monitoring programs.

  8. Bioaccumulation of BDE-47 and effects on molecular biomarkers acetylcholinesterase, glutathione-S-transferase and glutathione peroxidase in Mytilus galloprovincialis mussels.

    Vidal-Liñán, Leticia; Bellas, Juan; Fumega, José; Beiras, Ricardo

    2015-03-01

    Mussels, Mytilus galloprovincialis, showed a high bioaccumulation ability when exposed to waterborne tetrabromodiphenyl ether (BDE-47), with a bioconcentration factor of 10,900 L Kg(-1) wet weight, and slow depuration rates in clean seawater. Kinetic and concentration-response experiments were performed measuring in the exposed mussel the activities of three molecular biomarkers: glutathione S-transferase (GST), glutathione peroxidase (GPx) and acetylcholinesterase (AChE). The long term (30 days) exposure of mussels to all concentrations (2-15 µg L(-1)) of BDE-47 significantly inhibited the AChE and GST activities, a result that supports the suitability of these biomarkers in marine pollution monitoring programs. However, GPx activity showed a less consistent pattern of response depending on the concentration and the duration of exposure.

  9. Bioaccumulation of 4-nonylphenol and effects on biomarkers, acetylcholinesterase, glutathione-S-transferase and glutathione peroxidase, in Mytilus galloprovincialis mussel gilla.

    Vidal-Liñán, Leticia; Bellas, Juan; Salgueiro-González, Noelia; Muniategui, Soledad; Beiras, Ricardo

    2015-05-01

    Wild marine mussels, Mytilus galloprovincialis showed a moderate bioaccumulation ability when exposed to waterborne 4-nonylphenol (4-NP), with a bioconcentration factor (BCF) of 6850 L Kg(-1) (dry weight). Kinetic and concentration-response experiments were performed and three enzymatic biomarkers in mussel gills were measured: Glutathione S-transferase (GST), glutathione peroxidase (GPx) and acetylcholinesterase (AChE). Exposure of mussels to environmentally relevant concentrations (25-100 μg L(-1)) of 4-nonylphenol significantly inhibited the AChE activity and induced the GST and GPx activities. GST induction was dose dependent whilst GPx activity showed a less consistent pattern, but in both cases the induction remained after a 10 d depuration period. Mussels seem capable of eliminating 4-NP from their tissues through a mechanism involving GST induction.

  10. In vitro reactivation potency of acetylcholinesterase reactivators--K074 and K075--to reactivate tabun-inhibited human brain cholinesterases.

    Kuca, Kamil; Cabal, Jiri; Jun, Daniel; Musilek, Kamil

    2007-02-01

    In this work, two oximes for the treatment of tabun-inhibited acetylcholinesterase (AChE; EC 3.1.1.7), K074 (1,4-bis(4-hydroxyiminomethylpyridinium)butane dibromide) and K075 ((E)-1,4-bis(4-hydroxyiminomethylpyridinium)but-2-en dibromide), were tested in vitro as reactivators of AChE. Comparison was made with currently used AChE reactivators (pralidoxime, HI-6, methoxime and obidoxime). Human brain homogenate was taken as an appropriate source of the cholinesterases. As resulted, oxime K074 appears to be the most potent reactivator of tabun-inhibited AChE, with reactivation potency comparable to that of obidoxime. A second AChE reactivator, K075, does not attain as great a reactivation potency as K074, although its maximal reactivation (17%) was achieved at relevant concentrations for humans.

  11. In vitro studies on the effect of beta-carbolines on the activities of acetylcholinesterase and choline acetyltransferase and on the muscarinic receptor binding of the rat brain.

    Skup, M; Oderfeld-Nowak, B; Rommelspacher, H

    1983-07-01

    Acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7) activity and muscarinic receptor binding of homogenates from several brain structures were inhibited by beta-carbolines. The inhibition was of the noncompetitive type in the case of the enzyme and of the mixed type in the case of the receptor binding. This effect was most strongly manifested by pyridoindoles(harmane, norharmane), i.e., carbolines containing an aromatic C ring than by the corresponding piperidoindoles (tetrahydroharmane, tetrahydronorharmane), i.e., those with a reduced C ring. The activity of choline acetyltransferase (acetyl-CoA:choline O-acetyltransferase, EC 2.3.1.6) was not altered. These data are further evidence of the interactions between indoleamine derivatives and the cholinergic system. The results are discussed in terms of their possible biological significance.

  12. Ultra-sensitive biosensor based on genetically engineered acetylcholinesterase immobilized in poly (vinyl alcohol)/Fe-Ni alloy nanocomposite for phosmet detection in olive oil.

    El-Moghazy, A Y; Soliman, E A; Ibrahim, H Z; Noguer, T; Marty, J-L; Istamboulie, G

    2016-07-15

    An ultra-sensitive screen-printed biosensor was successfully developed for phosmet detection in olive oil, based on a genetically-engineered acetylcholinesterase (AChE) immobilized in a azide-unit water-pendant polyvinyl alcohol (PVA-AWP)/Fe-Ni alloy nanocomposite. Fe-Ni not only allowed amplifying the response current but also lowering the applied potential from 80 mV to 30 mV vs Ag/AgCl. The biosensor showed a very good analytical performance for phosmet detection, with a detection limit of 0.1 nM. This detection limit is lower than the allowable concentrations set by international regulations. In addition to the good reproducibility, operational and storage stability, the developed biosensor was successfully used for the determination of phosmet in olive oil samples without any laborious pre-treatment. The phosmet recovery rate was about 96% after a simple liquid-liquid extraction.

  13. Comparison of in vitro potency of oximes (pralidoxime, obidoxime, HI-6) to reactivate sarin-inhibited acetylcholinesterase in various parts of pig brain.

    Kuca, Kamil; Cabal, Jiri; Kassa, Jiri; Jun, Daniel; Hrabinová, Martina

    2005-01-01

    The potency of currently used oximes to reactivate sarin-inhibited acetylcholinesterase (AChE) in various parts of pig brain and whole pig brain was evaluated using in vitro methods. Significant differences in reactivation potency among all tested oximes were observed. At concentrations (10(-4) M) corresponding to recommended doses in vivo, the oxime HI-6 seems to be a more efficacious reactivator of sarin-inhibited AChE in whole pig brain as well as in cerebral hemispheres and cerebellum compared with the other oximes studied. Nevertheless, there are not any differences in the potency of oximes tested to reactivate sarin-inhibited AChE in medulla oblongata. Thus, the oxime HI-6 appears to be the most promising oxime among currently available oximes for the antidotal treatment of acute sarin poisoning, although it is not more efficacious than other currently used oximes in medulla oblongata, whose function is necessary for the vital functions of respiration and circulation.

  14. Effects of sub-lethal neurite outgrowth inhibitory concentrations of chlorpyrifos oxon on cytoskeletal proteins and acetylcholinesterase in differentiating N2a cells

    Flaskos, J., E-mail: flaskos@vet.auth.gr [Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Nikolaidis, E. [Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Harris, W. [School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS (United Kingdom); Sachana, M. [Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Hargreaves, A.J., E-mail: alan.hargreaves@ntu.ac.uk [School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS (United Kingdom)

    2011-11-15

    Previous work in our laboratory has shown that sub-lethal concentrations (1-10 {mu}M) of chlorpyrifos (CPF), diazinon (DZ) and diazinon oxon (DZO) inhibit the outgrowth of axon-like neurites in differentiating mouse N2a neuroblastoma cells concomitant with altered levels and/or phosphorylation state of axonal cytoskeleton and growth-associated proteins. The aim of the present work was to determine whether chlorpyrifos oxon (CPO) was capable of inhibiting N2a cell differentiation in a similar manner. Using experimental conditions similar to our previous work, sub-lethal concentrations (1-10 {mu}M) of CPO were found to inhibit N2a cell differentiation. However, unlike previous studies with DZ and DZO, there was a high level of sustained inhibition of acetylcholinesterase (AChE) in CPO treated cells. Impairment of neurite outgrowth was also associated with reduced levels of growth associated protein-43 and neurofilament heavy chain (NFH), and the distribution of NFH in cells stained by indirect immunofluorescence was disrupted. However, in contrast to previous findings for DZO, the absolute level of phosphorylated NFH was unaffected by CPO exposure. Taken together, the findings suggest that sub-lethal concentrations of CPO inhibit axon outgrowth in differentiating N2a cells and that this effect involves reduced levels of two proteins that play key roles in axon outgrowth and maintenance. Although the inhibition of neurite outgrowth is unlikely to involve AChE inhibition directly, further work will help to determine whether the persistent inhibition of AChE by CPO can account for the different effects induced by CPO and DZO on the levels of total and phosphorylated NFH. -- Highlights: Black-Right-Pointing-Pointer Sub-lethal levels of chlorpyrifos oxon inhibit neurite outgrowth in N2a cells Black-Right-Pointing-Pointer Acetylcholinesterase exhibits sustained inhibition throughout exposure Black-Right-Pointing-Pointer The levels of neurofilament heavy chain and GAP-43

  15. An amperometric biosensor based on acetylcholinesterase immobilized onto iron oxide nanoparticles/multi-walled carbon nanotubes modified gold electrode for measurement of organophosphorus insecticides

    Chauhan, Nidhi [Department of Biochemistry, M.D. University, Rohtak 124001, Haryana (India); Pundir, Chandra Shekhar, E-mail: pundircs@rediffmail.com [Department of Biochemistry, M.D. University, Rohtak 124001, Haryana (India)

    2011-09-02

    Graphical abstract: The stepwise amperometric biosensor fabrication process and immobilized acetylcholinesterase inhibition in pesticide solution. Highlights: {center_dot} Constructed a novel composite material using Fe{sub 3}O{sub 4}NP and c-MWCNT at Au electrode for electrocatalysis. {center_dot} The properties of nanoparticles modified electrodes were studied by SEM, FTIR, CVs and EIS. {center_dot} The biosensor exhibited good sensitivity (0.475 mA {mu}M{sup -1}) {center_dot} The half life of electrode was 2 months. {center_dot} The sensor was suitable for trace detection of OP pesticide residues in milk and water. - Abstract: An acetylcholinesterase (AChE) purified from maize seedlings was immobilized covalently onto iron oxide nanoparticles (Fe{sub 3}O{sub 4}NP) and carboxylated multi walled carbon nanotubes (c-MWCNT) modified Au electrode. An organophosphorus (OP) biosensor was fabricated using this AChE/Fe{sub 3}O{sub 4}/c-MWCNT/Au electrode as a working electrode, Ag/AgCl as standard and Pt wire as an auxiliary electrode connected through a potentiostat. The biosensor was based on inhibition of AChE by OP compounds/insecticides. The properties of nanoparticles modified electrodes were studied by scanning electron microscopy (SEM), Fourier transform infrared (FTIR), cyclic voltammograms (CVs) and electrochemical impedance spectroscopy (EIS). The synergistic action of Fe{sub 3}O{sub 4}NP and c-MWCNT showed excellent electrocatalytic activity at low potential (+0.4 V). The optimum working conditions for the sensor were pH 7.5, 35 deg. C, 600 {mu}M substrate concentration and 10 min for inhibition by pesticide. Under optimum conditions, the inhibition rates of OP pesticides were proportional to their concentrations in the range of 0.1-40 nM, 0.1-50 nM, 1-50 nM and 10-100 nM for malathion, chlorpyrifos, monocrotophos and endosulfan respectively. The detection limits were 0.1 nM for malathion and chlorpyrifos, 1 nM for monocrotophos and 10 nM for endosulfan. The

  16. Combined 3D-QSAR, molecular docking, and molecular dynamics study of tacrine derivatives as potential acetylcholinesterase (AChE) inhibitors of Alzheimer's disease.

    Zhou, An; Hu, Jianping; Wang, Lirong; Zhong, Guochen; Pan, Jian; Wu, Zeyu; Hui, Ailing

    2015-10-01

    Acetylcholinesterase (AChE) is one of the key targets of drugs for treating Alzheimer's disease (AD). Tacrine is an approved drug with AChE-inhibitory activity. In this paper, 3D-QSAR, molecular docking, and molecular dynamics were carried out in order to study 60 tacrine derivatives and their AChE-inhibitory activities. 3D-QSAR modeling resulted in an optimal CoMFA model with q(2) = 0.552 and r(2) = 0.983 and an optimal CoMSIA model with q(2) = 0.581 and r(2) = 0.989. These QSAR models also showed that the steric and H-bond fields of these compounds are important influences on their activities. The interactions between these inhibitors and AChE were further explored through molecular docking and molecular dynamics simulation. A few key residues (Tyr70, Trp84, Tyr121, Trp279, and Phe330) at the binding site of AChE were identified. The results of this study improve our understanding of the mechanisms of AChE inhibitors and afford valuable information that should aid the design of novel potential AChE inhibitors. Graphical Abstract Superposition of backbone atoms of the lowest-energy structure obtained from MD simulation (magenta) onto those of the structure of the initial molecular docking model (green).

  17. Molecular assembly and biosynthesis of acetylcholinesterase in brain and muscle: The roles of t-peptide, FHB domain and N-linked glycosylation

    Vicky P. Chen

    2011-10-01

    Full Text Available Acetylcholinesterase (AChE is responsible for the hydrolysis of the neurotransmitter, acetylcholine, in the nervous system. The functional localization and oligomerization of AChE T variant are depending primarily on the association of their anchoring partners, either collagen tail (ColQ or proline rich membrane anchor (PRiMA. Complexes with ColQ represent the asymmetric forms (A12 in muscle, while complexes with PRiMA represent tetrameric globular forms (G4 mainly found in brain and muscle. Apart from these traditional molecular forms, a ColQ-linked asymmetric form and a PRiMA-linked globular form of hybrid cholinesterases (ChEs, having both AChE and BChE catalytic subunits, were revealed in chicken brain and muscle. The similarity of various molecular forms of AChE and BChE raises interesting question regarding to their possible relationship in enzyme assembly and localization. The focus of this review is to provide current findings about the biosynthesis of different forms of ChEs together with their anchoring proteins.

  18. Computational analysis of novel drugs designed for use as acetylcholinesterase inhibitors and histamine H3 receptor antagonists for Alzheimer's disease by docking, scoring and de novo evolution.

    Chen, Po-Yuan; Tsai, Ching-Tsan; Ou, Che-Yen; Hsu, Wei-Tse; Jhuo, Mien-De; Wu, Chieh-Hsi; Shih, Tzu-Ching; Cheng, Tzu-Hurng; Chung, Jing-Gung

    2012-04-01

    Alzheimer's disease (AD) was first described by Alois Alzheimer in 1907. AD is the most prevalent dementia- related disease, affecting over 20 million individuals worldwide. Currently, however, only a handful of drugs are available and they are at best only able to offer some relief of symptoms. Acetylcholinesterase (AChE) inhibitors, antioxidants, metal chelators, monoamine oxidase inhibitors, anti-inflammatory drugs and NMDA inhibitors are usually used to attempt to cure this disease. AChE inhibitors are the most effective therapy for AD at present. Researchers have found that histamine H3 receptor antagonists decrease re-uptake of acetylcholine and the nervous transmitter substance acetylcholine increases. In this study, we designed compounds by using docking, de novo evolution and adsorption, distribution, metabolism, excretion and toxicity (ADMET) analysis to AChE inhibitors as well as histamine H3 receptor antagonists to forward drug research and investigate the potent compounds which can pass through the blood-brain barrier. The novel drugs may be useful for the treatment of AD, based on the results of this theoretical calculation study. We will subsequently examine them in future experiments.

  19. Pharmacological characterization of RS-1259, an orally active dual inhibitor of acetylcholinesterase and serotonin transporter, in rodents: possible treatment of Alzheimer's disease.

    Abe, Yasuyuki; Aoyagi, Atsushi; Hara, Takao; Abe, Kazumi; Yamazaki, Reina; Kumagae, Yoshihiro; Naruto, Shunji; Koyama, Kazuo; Marumoto, Shinji; Tago, Keiko; Toda, Narihiro; Takami, Kazuko; Yamada, Naho; Ori, Mayuko; Kogen, Hiroshi; Kaneko, Tsugio

    2003-09-01

    A dual inhibitor of acetylcholinesterase (AChE) and serotonin transporter (SERT), RS-1259 (4-[1S)-methylamino-3-(4-nitrophenoxy)]propylphenyl N,N-dimethylcarbamate (fumaric acid)(1/2)salt), was newly synthesized. RS-1259 simultaneously inhibited AChE and SERT in the brain following an oral administration in mice and rats. Actual simultaneous elevation of extracellular levels of 5-HT and ACh in the rat hippocampus was confirmed by microdialysis. The compound was as effective as SERT inhibitors such as fluoxetine and fluvoxamine in a 5-hydroxytryptophan-enhancing test in mice. Spatial memory deficits in the two-platform task of a water maze in aged rats were ameliorated by RS-1259 as well as donepezil. Both RS-1259 and donepezil increased the awake episodes in the daytime electroencephalogram of rats. Although RS-1259 was weaker than donepezil in enhancing central cholinergic transmission, as observed by ACh elevation in the hippocampus and memory enhancement in aged rats, the efficacy of RS-1259 on the consciousness level, which reflects the whole activity in the brain, was almost the same as that of donepezil. These results suggest that both cholinergic and serotonergic systems are involved in maintaining brain arousal and that a dual inhibitor of AChE and SERT may be useful for the treatment of cognitive disorders associated with reduced brain activity such as in Alzheimer's disease.

  20. Nickel in Soil Modifies Sensitivity to Diazinon Measured by the Activity of Acetylcholinesterase, Catalase, and Glutathione S-Transferase in Earthworm Eisenia fetida

    Agnieszka Zawisza-Raszka

    2013-01-01

    Full Text Available Nickel in typical soils is present in a very low concentration, but in the contaminated soils it occurs in locally elevated concentrations. The aim of this study was to examine the effect of nickel in the concentrations of 300 (very high, close to LOEC for reproduction and 900 (extremely high, close to LOEC for mortality mg/kg dry soil on the life history and acetylcholinesterase, catalase, and glutathione S-transferase activities in earthworm Eisenia fetida and to establish how nickel modifies the sensitivity to organophosphorous pesticide—diazinon. Cocoons production and juveniles’ number were significantly lower only in groups exposed to Ni in the concentration of 900 mg/kg dry soil for two months. Diazinon administration diminished the AChE activity in the GI tract and in the body wall. The interaction between diazinon and nickel was observed, and, in consequence, the AChE activity after the pesticide treatment was similar to controls in worms preexposed to nickel. Both pesticide administration and exposure to nickel caused an increase in the GST activity in examined organs and CAT activity in body wall. Both biometric and development data and simple enzymatic analysis, especially the AChE and GST, show a Ni pretreatment effect on the subsequent susceptibility to pesticide.

  1. Genotoxicity biomarkers and acetylcholinesterase activity in natural populations of Mytilus galloprovincialis along a pollution gradient in the Gulf of Oristano (Sardinia, western Mediterranean)

    Magni, P. [IMC - International Marine Centre, Localita Sa Mardini, 09072 Torregrande-Oristano (Italy); De Falco, G. [IMC - International Marine Centre, Localita Sa Mardini, 09072 Torregrande-Oristano (Italy); Falugi, C. [DIBISAA - Dipartimento di Biologia Sperimentale, Ambientale, Applicata, Universita di Genova, V.le Benedetto XV, 16132 Genoa (Italy); Franzoni, M. [DIBISAA - Dipartimento di Biologia Sperimentale, Ambientale, Applicata, Universita di Genova, V.le Benedetto XV, 16132 Genoa (Italy); Monteverde, M. [DIBISAA - Dipartimento di Biologia Sperimentale, Ambientale, Applicata, Universita di Genova, V.le Benedetto XV, 16132 Genoa (Italy); Perrone, E. [Environmental Carcinogenesis Unit, National Cancer Research Institute, Largo Rosanna Benzi 10, 16132 Genoa (Italy); Sgro, M. [DIBISAA - Dipartimento di Biologia Sperimentale, Ambientale, Applicata, Universita di Genova, V.le Benedetto XV, 16132 Genoa (Italy); Bolognesi, C. [Environmental Carcinogenesis Unit, National Cancer Research Institute, Largo Rosanna Benzi 10, 16132 Genoa (Italy)]. E-mail: claudia.bolognesi@istge.it

    2006-07-15

    A year-round biomonitoring study on blue mussels (Mytilus galloprovincialis) was carried out in 4 selected sites along the Gulf of Oristano (Sardinia, Italy): a commercial port (Port), the outlet of the S'Ena Arrubia and Marceddi lagoons (in the catchment area of intensive agricultural and diary activities, and abandoned mining), and a reference site (North). Heavy metal concentrations in sediments from Marceddi were 2-3 to 10-20 times higher in Pb, Cd and Zn, respectively, than those found at North and S'Ena Arrubia. Higher values (P < 0.05) of micronuclei frequency were detected in mussels from Marceddi and Port compared to those detected in mussels from North and S'Ena Arrubia. DNA damage in animals from North was significantly lower than that at the other sites. Results of acetylcholinesterase inhibition consistently showed the strongest effects in mussels from Port and Marceddi. Our results suggest that these biomarkers can be used in coastal marine biomonitoring as early signals of exposure and adverse effects along a pollution gradient. - Biomarkers can be useful in coastal marine biomonitoring.

  2. DEVELOPMENT OF REFERENCE RANGES FOR PLASMA TOTAL CHOLINESTERASE AND BRAIN ACETYLCHOLINESTERASE ACTIVITY IN FREE-RANGING CARNABY'S BLACK-COCKATOOS (CALYPTORHYNCHUS LATIROSTRIS).

    Vaughan-Higgins, Rebecca; Vitali, Simone; Reiss, Andrea; Besier, Shane; Hollingsworth, Tom; Smith, Gerard

    2016-07-01

    Published avian reference ranges for plasma cholinesterase (ChE) and brain acetylcholinesterase (AChE) are numerous. However, a consistently reported recommendation is the need for species- and laboratory-specific reference ranges because of variables, including assay methods, sample storage conditions, season, and bird sex, age, and physiologic status. We developed normal reference ranges for brain AChE and plasma total ChE (tChE) activity for Carnaby's Black-Cockatoos (Calyptorhynchus latirostris) using a standardized protocol (substrate acetylthiocholine at 25 C). We report reference ranges for brain AChE (19-41 μmol/min per g, mean 21±6.38) and plasma tChE (0.41-0.53 μmol/min per mL, mean 0.47±0.11) (n=15). This information will be of use in the ongoing field investigation of a paresis-paralysis syndrome in the endangered Carnaby's Black-Cockatoos, suspected to be associated with exposure to anticholinesterase compounds and add to the paucity of reference ranges for plasma tChE and brain AChE in Australian psittacine birds.

  3. 3-Oxoisoxazole-2(3H)-carboxamides and isoxazol-3-yl carbamates: Resistance-breaking acetylcholinesterase inhibitors targeting the malaria mosquito, Anopheles gambiae

    Verma, Astha; Wong, Dawn M.; Islam, Rafique; Tong, Fan; Ghavami, Maryam; Mutunga, James M.; Slebodnick, Carla; Li, Jianyong; Viayna, Elisabet; Lam, Polo C.-H.; Totrov, Maxim M.; Bloomquist, Jeffrey R.; Carlier, Paul R.

    2015-01-01

    To identify potential selective and resistance-breaking mosquitocides against the African malaria vector Anopheles gambiae, we investigated the acetylcholinesterase (AChE) inhibitory and mosquitocidal properties of isoxazol-3-yl dimethylcarbamates (15), and the corresponding 3-oxoisoxazole-2(3H)-dimethylcarboxamide isomers (14). In both series, compounds were found with excellent contact toxicity to wild-type susceptible (G3) strain and multiply resistant (Akron) strain mosquitoes that carry the G119S resistance mutation of AChE. Compounds possessing good to excellent toxicity to Akron strain mosquitoes inhibit the G119S mutant of An. gambiae AChE (AgAChE) with ki values at least 10- to 600-fold higher than that of propoxur, a compound that does not kill Akron mosquitoes at the highest concentration tested. On average, inactivation of WT AgAChE by dimethylcarboxamides 14 was 10-20 fold faster than that of the corresponding isoxazol-3-yl dimethylcarbamates 15. X-ray crystallography of dimethylcarboxamide 14d provided insight into that reactivity, a finding that may explain the inhibitory power of structurally-related inhibitors of hormone-sensitive lipase. Finally, human/An. gambiae AChE inhibition selectivities of these compounds were low, suggesting the need for additional structural modification. PMID:25684426

  4. A comparison of tabun-inhibited rat brain acetylcholinesterase reactivation by three oximes (HI-6, obidoxime, and K048) in vivo detected by biochemical and histochemical techniques.

    Bajgar, Jiri; Hajek, Petr; Zdarova, Jana Karasova; Kassa, Jiri; Paseka, Antonin; Slizova, Dasa; Krs, Otakar; Kuca, Kamil; Jun, Daniel; Fusek, Josef; Capek, Lukas

    2010-12-01

    Tabun belongs to the most toxic nerve agents. Its mechanism of action is based on acetylcholinesterase (AChE) inhibition at the peripheral and central nervous systems. Therapeutic countermeasures comprise administration of atropine with cholinesterase reactivators able to reactivate the inhibited enzyme. Reactivation of AChE is determined mostly biochemically without specification of different brain structures. Histochemical determination allows a fine search for different structures but is performed mostly without quantitative evaluation. In rats intoxicated with tabun and treated with a combination of atropine and HI-6, obidoxime, or new oxime K048, AChE activities in different brain structures were determined using biochemical and quantitative histochemical methods. Inhibition of AChE following untreated tabun intoxication was different in the various brain structures, having the highest degree in the frontal cortex and reticular formation and lowest in the basal ganglia and substantia nigra. Treatment resulted in an increase of AChE activity detected by both methods. The highest increase was observed in the frontal cortex. This reactivation was increased in the order HI-6 tabun, reactivation in various parts of the brain is not of the same physiological importance. AChE activity in the pontomedullar area and frontal cortex seems to be the most important for the therapeutic effect of the reactivators. HI-6 was not a good reactivator for the treatment of tabun intoxication.

  5. Kinetic analysis of interactions of different sarin and tabun analogues with human acetylcholinesterase and oximes: is there a structure-activity relationship?

    Aurbek, Nadine; Herkert, Nadja M; Koller, Marianne; Thiermann, Horst; Worek, Franz

    2010-09-06

    The repeated misuse of highly toxic organophosphorus compound (OP) based chemical warfare agents in military conflicts and terrorist attacks poses a continuous threat to the military and civilian sector. The toxic symptomatology of OP poisoning is mainly caused by inhibition of acetylcholinesterase (AChE, E.C. 3.1.1.7) resulting in generalized cholinergic crisis due to accumulation of the neurotransmitter acetylcholine (ACh) in synaptic clefts. Beside atropine as competitive antagonist of ACh at muscarinic ACh receptors oximes as reactivators of OP-inhibited AChE are a mainstay of standard antidotal treatment. However, human AChE inhibited by certain OP is rather resistant to oxime-induced reactivation. The development of more effective oxime-based reactivators may fill the gaps. To get more insight into a potential structure-activity relationship between human AChE, OPs and oximes in vitro studies were conducted to investigate interactions of different tabun and sarin analogues with human AChE and the oximes obidoxime and HI 6 by determination of various kinetic constants. Rate constants for the inhibition of human AChE by OPs, spontaneous dealkylation and reactivation as well as reactivation by obidoxime and HI 6 of OP-inhibited human AChE were determined. The recorded kinetic data did not allow a general statement concerning a structure-activity relationship between human AChE, OP and oximes.

  6. Novel nerve-agent antidote design based on crystallographic and mass spectrometric analyses of tabun-conjugated acetylcholinesterase in complex with antidotes.

    Ekström, F J; Astot, C; Pang, Y-P

    2007-09-01

    Organophosphorus compound-based nerve agents inhibit the essential enzyme acetylcholinesterase (AChE) causing acute toxicity and death. Clinical treatment of nerve-agent poisoning is to use oxime-based antidotes to reactivate the inhibited AChE. However, the nerve agent tabun is resistant to oximes. To design improved oximes, crystal structures of a tabun-conjugated AChE in complex with different oximes are needed to guide the structural modifications of known antidotes. However, this type of structure is extremely challenging to obtain because both deamidation of the tabun conjugate and reactivation of AChE occur during crystallographic experiments. Here we report, for the first time, the crystal structures of Ortho-7 and HLö-7 in complex with AChE that is conjugated to an intact tabun. These structures were determined by our new strategy of combining crystallographic and mass spectrometric analyses of AChE crystals. The results explain the relative reactivation potencies of the two oximes and offer insights into improving known medical antidotes.

  7. Enzyme immunoassay of benzyl penicilloyl (BPO) groups using acetylcholinesterase as label. Application to the study of the BPO-binding sites on albumin.

    Wal, J M; Yvon, M; Pradelles, P; Grassi, J

    1991-01-01

    Benzyl penicilloyl groups (BPO) derive from penicillin G by cleavage of the beta lactam ring; they covalently bind to proteins to give conjugates which have lost all antibiotic properties but are considered as the major allergenic determinants in penicillin allergy. A solid-phase Enzyme Immuno Assay (EIA) of BPO groups in different biological fluids is described. It is a competitive immunoassay using acetylcholinesterase as label. In all biological fluids, very low non-specific binding values are observed. The sensitivity and the precision of the assay are good since ca. 0.5 ng/ml can be measured with a coefficient of variation less than 10%. Cross reactions between BPO and penicillin or penicillin derivatives are nil or very low. This assay is more sensitive, much more rapid and easier to handle than the other methods available and is thus suitable for routine determinations. In association with reversed-phase high performance liquid chromatography this EIA has allowed an initial investigation of the location of BPO-binding sites on micro quantities of serum albumin (ca. 1 mg) from penicillin treated patients.

  8. Acetylcholinesterase activity in the brain of alloxan diabetic albino rats: Presence of an inhibitor of this enzyme activity in the cerebral extract

    Ahmed, Nayeemunnisa; Tarannum, Suraiya

    2009-01-01

    Background and Aim: Ischemic manifestations and cerebral dysfunction have been demonstrated in diabetes. However, the pathogenesis of diabetes-induced cerebral dysfunction still remains to be elucidated. Hence, the present study was initiated. Materials and Methods: Type-2 diabetes was induced in albino rats (280–300g) with alloxan monohydrate (40 mg/Kg i.v.,) and the cerebrum, cerebellum and medulla oblongata of the brain were used 48 h after alloxan injection for modulations in acetylcholinesterase (AChE, EC 3.1.1.7) activity. Results: AChE activity in the discrete regions of the brain of rats decreased significantly (P<0.01, 0.05 and 0.05 respectively) in diabetes. In vitro studies using cerebral extract from alloxan diabetic rats demonstrated significant (P<0.05) inhibition of AChE activity in the brain of normal animals. Feeding with Cichorium intybus (chicory) leaf extract (500 mg/Kg) for 10 days resulted in an increase in AChE activity. Conclusion: The impairment in the glycemic control is the basic mechanism causing inhibition of neuronal activity. Cerebral extract from alloxan diabetic rats significantly inhibited the brain AChE activity of normal animals, indicating the presence of an inhibiting factor in the cerebrum of diabetic rats. Cichorium intybus when fed for 10 days offered neuroprotection by stimulating AChE activity. PMID:20336201

  9. Intraperitoneal Exposure to Nano/Microparticles of Fullerene (C60 Increases Acetylcholinesterase Activity and Lipid Peroxidation in Adult Zebrafish (Danio rerio Brain

    Gonzalo Ogliari Dal Forno

    2013-01-01

    Full Text Available Even though technologies involving nano/microparticles have great potential, it is crucial to determine possible toxicity of these technological products before extensive use. Fullerenes C60 are nanomaterials with unique physicochemical and biological properties that are important for the development of many technological applications. The aim of this study was to evaluate the consequences of nonphotoexcited fullerene C60 exposure in brain acetylcholinesterase expression and activity, antioxidant responses, and oxidative damage using adult zebrafish as an animal model. None of the doses tested (7.5, 15, and 30 mg/kg altered AChE activity, antioxidant responses, and oxidative damage when zebrafish were exposed to nonphotoexcited C60 nano/microparticles during 6 and 12 hours. However, adult zebrafish exposed to the 30 mg/kg dose for 24 hours have shown enhanced AChE activity and augmented lipid peroxidation (TBARS assays in brain. In addition, the up-regulation of brain AChE activity was neither related to the transcriptional control (RT-qPCR analysis nor to the direct action of nonphotoexcited C60 nano/microparticles on the protein (in vitro results but probably involved a posttranscriptional or posttranslational modulation of this enzymatic activity. Taken together these findings provided further evidence of toxic effects on brain after C60 exposure.

  10. Water Extractable Phytochemicals from Peppers (Capsicum spp. Inhibit Acetylcholinesterase and Butyrylcholinesterase Activities and Prooxidants Induced Lipid Peroxidation in Rat Brain In Vitro

    Omodesola O. Ogunruku

    2014-01-01

    Full Text Available Background. This study sought to investigate antioxidant capacity of aqueous extracts of two pepper varieties (Capsicum annuum var. accuminatum (SM and Capsicum chinense (RO and their inhibitory effect on acetylcholinesterase and butyrylcholinesterase activities. Methods. The antioxidant capacity of the peppers was evaluated by the 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS radical scavenging ability and ferric reducing antioxidant property. The inhibition of prooxidant induced lipid peroxidation and cholinesterase activities in rat brain homogenates was also evaluated. Results. There was no significant difference (P>0.05 in the total phenol contents of the unripe and ripe Capsicum spp. extracts. Ripe and unripe SM samples had significantly higher (P<0.05 ABTS* scavenging ability than RO samples, while the ripe fruits had significantly higher (P<0.05 ferric reducing properties in the varieties. Furthermore, the extracts inhibited Fe2+ and quinolinic acid induced lipid peroxidation in rats brain homogenates in a dose-dependent manner. Ripe and unripe samples from SM had significantly higher AChE inhibitory abilities than RO samples, while there was no significant difference in the BuChE inhibitory abilities of the pepper samples. Conclusion. The antioxidant and anticholinesterase properties of Capsicum spp. may be a possible dietary means by which oxidative stress and symptomatic cognitive decline associated with neurodegenerative conditions could be alleviated.

  11. Synthesis and in-vitro reactivation screening of imidazolium aldoximes as reactivators of sarin and VX-inhibited human acetylcholinesterase (hAChE).

    Sharma, Rahul; Gupta, Bhanushree; Sahu, Arvind Kumar; Acharya, Jyotiranjan; Satnami, Manmohan L; Ghosh, Kallol K

    2016-11-25

    Post-treatment of organophosphate (OP) poisoning involves the application of oxime reactivator as an antidote. Structurally different oximes are widely studied to examine their kinetic and mechanistic behavior against OP-inhibited cholinesterase enzyme. A series of structurally related 1,3-disubstituted-2-[(hydroxyiminomethyl)alkyl]imidazolium halides (5a-5e, 9a-9c) were synthesized and further evaluated for their in-vitro reactivation ability to reactivate sarin- and VX-inhibited human acetylcholinesterase (hAChE). The observed results were compared with the reactivation efficacy of standard reactivators; 2-PAM, obidoxime and HI-6. Amongst the synthesized oximes, 5a, 9a and 9b were found to be most potent reactivators against sarin-inhibited hAChE while in case of VX only 9a exhibited comparable reactivity with 2-PAM. Incorporation of pyridinium ring to the imidazole ring resulted in substantial increase in the reactivation strength of prepared reactivator. Physicochemical properties of synthesized reactivators have also been evaluated.

  12. Avaliação da inibição da acetilcolinesterase por extratos de plantas medicinais Evaluation of acetylcholinesterase inhibition by extracts from medicinal plants

    W.M. Mota

    2012-01-01

    Full Text Available Neste trabalho foi avaliada a atividade inibitória da acetilcolinesterase (AChE pelo método de Ellman, modificado por Rhee, de extratos aquosos e etanólicos de oito plantas utilizadas na medicina popular da região Nordeste do Brasil. O extrato aquoso de E. velutina não apresentou atividade inibitória enquanto o extrato aquoso de Maytenus rigida apresentou baixa atividade inibitória (percentual de inibição de 4%. Detectou-se atividade inibitória moderada com o extrato aquoso de P. piperoides (percentual de inibição de 40 %, enquanto o extrato de V. agnus-castus L. inibiu 74% da atividade da AChE, caracterizando-se como potente atividade inibitória. A avaliação da inibição da AChE com os extratos etanólicos demonstrou que os extratos de Sideroxylon obtusifolium, Erythrina velutina, Vitex agnus-castus, Phoradendron piperoides, Chrysobalanus icaco, Bauhinia cheilantha e Orbignya phalerata não apresentaram atividade inibitória. Baixa atividade inibitória foi observada com os extratos etanólicos de Maytenus rigida (percentual de inibição de 7% e de Hyptis fruticosa (percentual de inibição de 11%. O extrato etanólico de Moringa oleifera apresentou atividade inibitória moderada, inibindo 47% da atividade dessa enzima. Nenhum dos extratos etanólicos testados apresentou atividade inibitória potente da AChE. Os resultados dos estudos de inibição da acetilcolinesterase permitem concluir que o extrato aquoso de V. agnus-castus L. mostrou-se o mais eficaz quanto a inibição da AChE. Este resultado reforça a necessidade da continuidade do estudo desse extrato, de forma a realizar a partição do extrato e a purificação das frações para isolar a molécula responsável pela inibição observada.In this study, we evaluated the inhibitory activity against acetylcholinesterase (AChE according to Ellman's method, modified by Rhee, for ethanol and aqueous extracts from eight plants used in folk medicine in the northeast region of

  13. Evaluation of the binding characteristics of [5-{sup 11}C-methoxy]donepezil in the rat brain for in vivo visualization of acetylcholinesterase

    Funaki, Yoshihito; Iwata, Ren; Ido, Tatsuo [Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center; Kato, Motohisa; Sakurai, Eiko; Tashiro, Manabu; Yanai, Kazuhiko [Tohoku Univ., Sendai (Japan). Graduate School of Medicine; Sakurai, Eiichi [Tohoku Coll. of Pharmacy, Sendai (Japan)

    2003-02-01

    Donepezil, an acetylcholinesterase (AChE) inhibitor, has not been evaluated for its binding characteristics using a radioactive tracer, although its inhibitory action on AChE has been studied. The aim of this research is to examine whether AChE can be visualized in vivo and in vitro with [{sup 11}C]donepezil. [5-{sup 11}C-methoxy]donepezil was synthesized by O-methylation using [{sup 11}C]methyl triflate. The binding of [{sup 11}C]donepezil to brain homogenates was higher in the brain stem and striatum, and it was lowest in the cerebellum. The in vitro autoradiographic study successfully demonstrated the specific binding of [{sup 11}C]donepezil to AChE in the rat brain. The IC{sub 50} value of binding was approximately 10 nM, which is comparable to the reported value for inhibiting enzyme activity (6 nM). Saturation experiments revealed that the B{sub max} and K{sub d} of [{sup 11}C]donepezil binding in vitro are 65 fmol/mg tissue and 39.8 nM, respectively. In accordance with the in vitro bindings, the in vivo distribution of [{sup 11}C]donepezil was heterogeneous in the rat brain. In the blocking experiments, the heterogeneous distribution disappeared in the presence of a large amount of unlabeled donepezil. These data suggest that [5-{sup 11}C-methoxy]donepezil can be potentially useful to image AChE non-invasively in the human brain by positron emission tomography. (author)

  14. Effects of exposure to oxamyl, carbofuran, dichlorvos, and lindane on acetylcholinesterase activity in the gills of the Pacific oyster Crassostrea gigas.

    Anguiano, Gerardo A; Amador, Alejandro; Moreno-Legorreta, Manuel; Arcos-Ortega, Fabiola; Vazquez-Boucard, Celia

    2010-08-01

    Acetylcholinesterase (AChE) activity has been used to test the exposure of mollusk bivalves to pesticides and other pollutants. The Pacific oyster Crassostrea gigas is a species with a worldwide distribution, and it has a high commercial value. The use of this species as a bioindicator in the marine environment, and the use of measurements of AChE activity in tissues of C. gigas require prior evaluation of organisms exposed to several toxic compounds in the laboratory. In our study, the effects of pesticides on AChE activity in the gills and mantle tissues of C. gigas were analyzed by exposing animals to organophosphate (dichlorvos), carbamate (carbofuran and oxamyl), and organochlorine (lindane) pesticides. Adult Pacific oysters were exposed to several concentrations (0.1-200 microM) of dichlorvos, carbofuran, and oxamyl for 96 h, and lindane (1.0 and 2.5 microM) was applied for 12 days. In gill tissues, all pesticides analyzed caused a decrease in AChE activity when compared to the control unexposed group. The mean inhibition concentration (IC(50)) values were determined for dichlorvos, carbofuran, and oxamyl pesticides. Dichlorvos had the highest toxic effect, with an IC(50) of 1.08 microM; lesser effects were caused by oxamyl and carbofuran, with IC(50)s of 1.67 and 3.03 microM, respectively. This study reports the effects of pesticides with several chemical structures and validates measurement of AChE activity in the gill tissues of C. gigas for use in environmental evaluations or food quality tests.

  15. Highly Sensitive and Selective Immuno-capture/Electrochemical Assay of Acetylcholinesterase Activity in Red Blood Cells: A Biomarker of Exposure to Organophosphorus Pesticides and Nerve Agents

    Chen, Aiqiong; Du, Dan; Lin, Yuehe

    2012-02-09

    Acetylcholinesterase (AChE) enzyme activity in red blood cells (RBCs) is a useful biomarker for biomonitoring of exposures to organophosphorus (OP) pesticides and chemical nerve agents. In this paper, we reported a new method for AChE activity assay based on selective immuno-capture of AChE from biological samples followed by enzyme activity assay of captured AChE using a disposable electrochemical sensor. The electrochemical sensor is based on multiwalled carbon nanotubes-gold nanocomposites (MWCNTs-Au) modified screen printed carbon electrode (SPCE). Upon the completion of immunoreaction, the target AChE (including active and inhibited) is captured onto the electrode surface and followed by an electrochemical detection of enzymatic activity in the presence of acetylthiocholine. A linear response is obtained over standard AChE concentration range from 0.1 to 10 nM. To demonstrate the capability of this new biomonitoring method, AChE solutions dosed with different concentration of paraoxon were used to validate the new AChE assay method. AChE inhibition in OP dosed solutions was proportional to its concentration from 0.2 to 50 nM. The new AChE activity assay method for biomonitoring of OP exposure was further validated with in-vitro paraoxon-dosed RBC samples. The established electrochemical sensing platform for AChE activity assay not only avoids the problem of overlapping substrate specificity with esterases by using selective antibody, but also eliminates potential interference from other electroactive species in biological samples. It offers a new approach for sensitive, selective, and rapid AChE activity assay for biomonitoring of exposures to OPs.

  16. A mechanism-based 3D-QSAR approach for classification and prediction of acetylcholinesterase inhibitory potency of organophosphate and carbamate analogs

    Lee, Sehan; Barron, Mace G.

    2016-04-01

    Organophosphate (OP) and carbamate esters can inhibit acetylcholinesterase (AChE) by binding covalently to a serine residue in the enzyme active site, and their inhibitory potency depends largely on affinity for the enzyme and the reactivity of the ester. Despite this understanding, there has been no mechanism-based in silico approach for classification and prediction of the inhibitory potency of ether OPs or carbamates. This prompted us to develop a three dimensional prediction framework for OPs, carbamates, and their analogs. Inhibitory structures of a compound that can form the covalent bond were identified through analysis of docked conformations of the compound and its metabolites. Inhibitory potencies of the selected structures were then predicted using a previously developed three dimensional quantitative structure-active relationship. This approach was validated with a large number of structurally diverse OP and carbamate compounds encompassing widely used insecticides and structural analogs including OP flame retardants and thio- and dithiocarbamate pesticides. The modeling revealed that: (1) in addition to classical OP metabolic activation, the toxicity of carbamate compounds can be dependent on biotransformation, (2) OP and carbamate analogs such as OP flame retardants and thiocarbamate herbicides can act as AChEI, (3) hydrogen bonds at the oxyanion hole is critical for AChE inhibition through the covalent bond, and (4) π-π interaction with Trp86 is necessary for strong inhibition of AChE. Our combined computation approach provided detailed understanding of the mechanism of action of OP and carbamate compounds and may be useful for screening a diversity of chemical structures for AChE inhibitory potency.

  17. Synthesis and in silico evaluation of 1N-methyl-1S-methyl-2-nitroethylene (NMSM) derivatives against Alzheimer disease: to understand their interacting mechanism with acetylcholinesterase.

    Kannan, M; Manivel, P; Geetha, K; Muthukumaran, J; Rao, H Surya Prakash; Krishna, R

    2012-01-01

    Anomalous action of human acetylcholinesterase (hAChE) in Alzheimer's disease (AD) was restrained by various AChE inhibitors, of which the specific and potent lead candidate Donepezil is used for treating the disease AD. Besides the specificity, the observed undesirable side effects caused by Donepezil invoked the quest for new lead molecules with the increased potency and specificity for AChE. The present study elucidates the potency of six 1N-methyl-1S-methyl-2-nitroethylene (NMSM) derivatives to form a specific interaction with the peripheral anionic site and catalytic anionic subsite residues of hAChE. The NMSMs were prepared in good yield from 1,1-di(methylsulfanyl)-2-nitroethylene and primary amine (or) amino acid esters. In silico interaction analysis reveals specific and potent interactions between hAChE and selected ligand molecules. The site-specific interactions formed between these molecules also results in a conformational change in the orientation of active site residues of hAChE, which prevents them from being accessed by beta-amyloid protein (Aβ), which is a causative agent for amyloid plaque formation and acetylcholine (ACh). In silico interaction analysis between the ligand-bounded hAChE with Aß and ACh confirms this observation. The variation in the conformation of hAChE associated with the decreased ability of Aβ and ACh to access the respective functional residues of hAChE induced by the novel NMSMs favors their selection for in vivo analysis to present themselves as new members of hAChE inhibitors.

  18. Inhibition of acetylcholinesterase activity in the central nervous system of the red swamp crayfish, Procambarus clarkii, by mercury, cadmium, and lead

    Devi, M.; Fingerman, M. [Tulane Univ., New Orleans, LA (United States)

    1995-11-01

    The toxicological, physiological and biochemical responses of aquatic crustaceans to heavy metals have been reported by several investigators. Levels of glucose, lactic acid, sodium, potassium, aspartate aminotransferase and alanine aminotransferase in the blood of the crab Scylla serrata increased, while glycogen levels in hepatopancreas and muscle decreased after a four-week exposure to mercuric chloride. In fiddler crab, Uca pugilator, enzyme activity was observed to decrease in the hepatopancreas but increased in abdominal muscle after 48 hr cadmium exposure. In the red swamp crayfish, Procambarus clarkii, exposed for 96 hr to cadmium, glutahione (GSH) level and GSH S-transferase activity deceased in the midgut. In crayfish Astacus astacus exposed to sublethal concentrations of lead and cadmium, oxidative enzyme (succine dehydrogenase and NADPH-cytochrome P450 reductase) activities in gills and hepatopancrease decreased. Acetylcholinesterase (AChE) inhibition by organophosphates and organocarbamates in various crustaceans has bee reported. In vivo cadmium exposure caused increases in esterase activities, but mercury exposure decreases these activities in the hepatopancreas of the shrimp Callianassa tyrrhena. The freshwater crab, Barytelphusa guerini, exposed to 0.6 ppm cadmium showed reduced oxygen consumption throughout the experiment whereas AChE activity increased after 4 days but decreased after 15 days. The authors wanted to determine the effects of cadmium, lead and mercury on AChE activity in central nervous tissue of Procambarus clarkii. This enzyme has the potential for serving both as a biochemical indicator of toxic stress and a sensitive parameter for testing water for the presence of toxicants. These three biologically silent metals have, according to Schweinsberg and Karsa great toxicological significance to humans because their use is widespread. 14 refs., 4 figs.

  19. Naturally Occurring Genetic Variants of Human Acetylcholinesterase and Butyrylcholinesterase and Their Potential Impact on the Risk of Toxicity from Cholinesterase Inhibitors

    2016-01-01

    Acetylcholinesterase (AChE) is the physiologically important target for organophosphorus toxicants (OP) including nerve agents and pesticides. Butyrylcholinesterase (BChE) in blood serves as a bioscavenger that protects AChE in nerve synapses from inhibition by OP. Mass spectrometry methods can detect exposure to OP by measuring adducts on the active site serine of plasma BChE. Genetic variants of human AChE and BChE do exist, but loss of function mutations have been identified only in the BCHE gene. The most common AChE variant, His353Asn (H322N), also known as the Yt blood group antigen, has normal AChE activity. The most common BChE variant, Ala567Thr (A539T) or the K-variant in honor of Werner Kalow, has 33% reduced plasma BChE activity. The genetic variant most frequently associated with prolonged response to muscle relaxants, Asp98Gly (D70G) or atypical BChE, has reduced activity and reduced enzyme concentration. Early studies in young, healthy males, performed at a time when it was legal to test nerve agents in humans, showed that individuals responded differently to the same low dose of sarin with toxic symptoms ranging in severity from minimal to moderate. Additionally, animal studies indicated that BChE protects from toxicants that have a higher reactivity with AChE than with BChE (e.g., nerve agents) but not from toxicants that have a higher reactivity with BChE than with AChE (e.g., OP pesticides). As a corollary, we hypothesize that individuals with genetic variants of BChE may be at increased risk of toxicity from nerve agents but not from OP pesticides. PMID:27551784

  20. Synthesis and evaluation of 2-[{sup 18}F]fluoro-CP-118,954 for the in vivo mapping of acetylcholinesterase

    Kyoung Ryu, Eun [Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 135-710 Seoul (Korea, Republic of); Choe, Yearn Seong [Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 135-710 Seoul (Korea, Republic of)]. E-mail: ysnm.choe@samsung.com; Park, Eun Young [Department of Nuclear Medicine, Seoul National University College of Medicine, 110-744 Seoul (Korea, Republic of); Paik, Jin-Young [Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 135-710 Seoul (Korea, Republic of); Kim, Yu Ri [Department of Nuclear Medicine, Seoul National University College of Medicine, 110-744 Seoul (Korea, Republic of); Lee, Kyung-Han [Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 135-710 Seoul (Korea, Republic of); Choi, Yong [Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 135-710 Seoul (Korea, Republic of); Kim, Sang Eun [Department of Nuclear Medicine, Seoul National University College of Medicine, 110-744 Seoul (Korea, Republic of); Kim, Byung-Tae [Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 135-710 Seoul (Korea, Republic of)

    2005-02-01

    5,7-Dihydro-3-[2-[1-(2-fluorobenzyl)-4-piperidinyl]ethyl]-6H-pyrrolo[3,2,f= ] - 1,2-benzisoxazol-6-one (2-fluoro-CP-118,954; 1), a potent acetylcholinesterase (AChE) inhibitor, was prepared as a radioligand by reductive alkylation of CP-144,885 the debenzylated form of CP 118,954, with 2-[{sup 18}F]fluorobenzaldehyde. The decay-corrected radiochemical yield was 25-30% and the effective specific activity was 41-53 GBq/{mu}mol. Tissue distribution studies of 2-[{sup 18}F]fluoro-CP-118,954 ([{sup 18}F]) in mice showed that the regional brain distribution correlated well with the known density of AChE in the mouse brain. A high level of uptake in the striatum was also shown at all time points in the olfactory tubercle, which is known to have dopaminergic neurons. Blocking studies showed that radioligand uptake in all brain regions was not altered by either the dopamine receptor antagonists or the sigma receptor agonist. On the other hand, radioligand uptake in both the striatum and the olfactory tubercle was significantly blocked (80%) by ligand . The low level of bone uptake over time suggested that [{sup 18}F] underwent little in vivo metabolic defluorination. The lack of metabolite formation in the mouse brain indicated that the regional distribution was attributed to [{sup 18}F]. These results demonstrated that [{sup 18}F] binds specifically and selectively to AChE in mice and appears to be a suitable radioligand for the in vivo mapping of AChE.

  1. A sensitive magnetic nanoparticle-based immunoassay of phosphorylated acetylcholinesterase using protein cage templated lead phosphate for signal amplification with graphite furnace atomic absorption spectrometry detection.

    Liang, Pei; Kang, Caiyan; Yang, Enjian; Ge, Xiaoxiao; Du, Dan; Lin, Yuehe

    2016-04-01

    We developed a new magnetic nanoparticle sandwich-like immunoassay using protein cage nanoparticles (PCN) for signal amplification together with graphite furnace atomic absorption spectrometry (GFAAS) for the quantification of an organophosphorylated acetylcholinesterase adduct (OP-AChE), the biomarker of exposure to organophosphate pesticides (OPs) and nerve agents. OP-AChE adducts were firstly captured by titanium dioxide coated magnetic nanoparticles (TiO2-MNPs) from the sample matrixes through metal chelation with phospho-moieties, and then selectively recognized by anti-AChE antibody labeled on PCN which was packed with lead phosphate in its cavity (PCN-anti-AChE). The sandwich-like immunoreaction was performed among TiO2-MNPs, OP-AChE and PCN-anti-AChE to form a TiO2-MNP/OP-AChE/PCN-anti-AChE immunocomplex. The complex could be easily isolated from the sample solution with the help of magnet, and the released lead ions from PCN were detected by GFAAS for the quantification of OP-AChE. Greatly enhanced sensitivity was achieved because PCN increased the amount of metal ions in the cavity of each apoferritin. The proposed immunoassay yielded a linear response over a broad range of OP-AChE concentrations from 0.01 nM to 2 nM, with a detection limit of 2 pM, which has enough sensitivity for monitoring of low-dose exposure to OPs. This new method showed an acceptable stability and reproducibility and was validated with OP-AChE spiked human plasma.

  2. Sensitive magnetic nanoparticle-based immunoassay of phosphorylated acetylcholinesterase using protein cage templated lead phosphate for signal amplification with graphite furnace atomic absorption spectrometry detection

    Liang, Pei; Kang, Caiyan; Yang, Enjian; Ge, Xiaoxiao; Du, Dan; Lin, Yuehe

    2016-01-01

    We developed a new magnetic nanoparticles sandwich-like immunoassay using protein cage nanoparticles (PCN) for signal amplification together with graphite furnace atomic absorption spectrometry (GFAAS) for quantification of organophosphorylated acetylcholinesterase adduct (OP-AChE), the biomarker of exposure to organophosphate pesticides (OPs) and nerve agents. OP-AChE adducts were firstly captured by titanium dioxide coated magnetic nanoparticles (TiO2-MNPs) from the sample matrixes through metal chelation with phospho-moieties, and then selectively recognized by anti-AChE antibody labeled on PCN which was packed with lead phosphate in its cavity (PCN-anti-AChE). The sandwich-like immunoreaction was performed among TiO2-MNPs, OP-AChE and PCN-anti-AChE to form TiO2-MNPs/OP-AChE/PCN-anti-AChE immunocomplex. The complex could be easily isolated from the sample solution with the help of magnet, and the released lead ions from PCN were detected by GFAAS for the quantification of OP-AChE. Greatly enhanced sensitivity was achieved because PCN increased the amount of metal ions in the cavity of each apoferritin. The proposed immunoassay yielded a linear response over a broad OP-AChE concentrations from 0.01 nM to 2 nM, with a detection limit of 2 pM, which has enough sensitivity for monitoring of low-dose exposure to OPs. This new method showed an acceptable stability and reproducibility and was validated with OP-AChE spiked human plasma. PMID:26953358

  3. Silicon Reverses Lipid Peroxidation but not Acetylcholinesterase Activity Induced by Long-Term Exposure to Low Aluminum Levels in Rat Brain Regions.

    Noremberg, Simone; Bohrer, Denise; Schetinger, Maria R C; Bairros, André V; Gutierres, Jessié; Gonçalves, Jamile F; Veiga, Marlei; Santos, Francielli W

    2016-01-01

    Aluminum (Al) is the most widely distributed metal in the environment and is extensively used in daily life leading to easy exposure to human beings. Besides not having a recognized physiological role, Al may produce adverse effects through the interaction with the cholinergic system contributing to oxidative stress. The present study evaluated, in similar conditions of parenteral nutrition, whether the reaction of silicon (SiO2) with Al(3+) to form hydroxyaluminosilicates (HAS) reduces its bioavailability and toxicity through intraperitoneal administrations of 0.5 mg Al/kg/day and/or 2 mg Si/kg/day in Wistar rats. Al and Si concentrations were determined in rat brain tissue and serum. Acetylcholinesterase (AChE) activity and lipid peroxidation (LPO) were analyzed in the cerebellum, cortex, hippocampus, striatum, hypothalamus, and blood. An increase in the Al concentration was verified in the Al + Si group in the brain. All the groups demonstrated enhanced Si compared to the control animals. Al(3+) increased LPO measured by thiobarbituric acid reactive substances (TBARS) in cerebellum and hippocampus, whereas SiO2 reduced it when compared with the control group. An increase of AChE activity was observed in the Al-treated group in the cerebellum whereas a decrease of this enzyme activity was observed in the cortex and hippocampus in the Al and Al + Si groups. Al and Si concentrations increased in rat serum; however, no effect was observed in blood TBARS levels and AChE activity. SiO2 showed a protective effect in the hippocampus and cerebellum against cellular damage caused by Al(3+)-induced lipid peroxidation. Thus, SiO2 may be considered an important protector in LPO induced by Al(3+).

  4. Structure of HI-6*sarin-acetylcholinesterase determined by X-ray crystallography and molecular dynamics simulation: reactivator mechanism and design.

    Fredrik Ekström

    Full Text Available Organophosphonates such as isopropyl metylphosphonofluoridate (sarin are extremely toxic as they phosphonylate the catalytic serine residue of acetylcholinesterase (AChE, an enzyme essential to humans and other species. Design of effective AChE reactivators as antidotes to various organophosphonates requires information on how the reactivators interact with the phosphonylated AChEs. However, such information has not been available hitherto because of three main challenges. First, reactivators are generally flexible in order to change from the ground state to the transition state for reactivation; this flexibility discourages determination of crystal structures of AChE in complex with effective reactivators that are intrinsically disordered. Second, reactivation occurs upon binding of a reactivator to the phosphonylated AChE. Third, the phosphorous conjugate can develop resistance to reactivation. We have identified crystallographic conditions that led to the determination of a crystal structure of the sarin(nonaged-conjugated mouse AChE in complex with [(E-[1-[(4-carbamoylpyridin-1-ium-1-ylmethoxymethyl]pyridin-2-ylidene]methyl]-oxoazanium dichloride (HI-6 at a resolution of 2.2 A. In this structure, the carboxyamino-pyridinium ring of HI-6 is sandwiched by Tyr124 and Trp286, however, the oxime-pyridinium ring is disordered. By combining crystallography with microsecond molecular dynamics simulation, we determined the oxime-pyridinium ring structure, which shows that the oxime group of HI-6 can form a hydrogen-bond network to the sarin isopropyl ether oxygen, and a water molecule is able to form a hydrogen bond to the catalytic histidine residue and subsequently deprotonates the oxime for reactivation. These results offer insights into the reactivation mechanism of HI-6 and design of better reactivators.

  5. In vivo labelling of hippocampal beta-amyloid in triple-transgenic mice with a fluorescent acetylcholinesterase inhibitor released from nanoparticles.

    Härtig, Wolfgang; Kacza, Johannes; Paulke, Bernd-Reiner; Grosche, Jens; Bauer, Ute; Hoffmann, Anke; Elsinghorst, Paul W; Gütschow, Michael

    2010-01-01

    The drastic loss of cholinergic projection neurons in the basal forebrain is a hallmark of Alzheimer's disease (AD), and drugs most frequently applied for the treatment of dementia include inhibitors of the acetylcholine-degrading enzyme acetylcholinesterase (AChE). This protein is known to act as a ligand of beta-amyloid (Abeta) in senile plaques, a further neuropathological sign of AD. Recently, we have shown that the fluorescent, heterodimeric AChE inhibitor PE154 allows for the histochemical staining of cortical Abeta plaques in triple-transgenic (TTG) mice with age-dependent beta-amyloidosis and tau hyperphosphorylation, an established animal model for aspects of AD. In the present study, we have primarily demonstrated the targeting of Abeta-immunopositive plaques with PE154 in vivo for 4 h up to 1 week after injection into the hippocampi of 13-20-month-old TTG mice. Numerous plaques, double-stained for PE154 and Abeta-immunoreactivity, were revealed by confocal laser-scanning microscopy. Additionally, PE154 targeted hippocampal Abeta deposits in aged TTG mice after injection of carboxylated polyglycidylmethacrylate nanoparticles delivering the fluorescent marker in vivo. Furthermore, biodegradable core-shell polystyrene/polybutylcyanoacrylate nanoparticles were found to be suitable, alternative vehicles for PE154 as a useful in vivo label of Abeta. Moreover, we were able to demonstrate that PE154 targeted Abeta, but neither phospho-tau nor reactive astrocytes surrounding the plaques. In conclusion, nanoparticles appear as versatile carriers of AChE inhibitors and other promising drugs for the treatment of AD.

  6. Catalytic-site conformational equilibrium in nerve-agent adducts of acetylcholinesterase: possible implications for the HI-6 antidote substrate specificity.

    Artursson, Elisabet; Andersson, Per Ola; Akfur, Christine; Linusson, Anna; Börjegren, Susanne; Ekström, Fredrik

    2013-05-01

    Nerve agents such as tabun, cyclosarin and Russian VX inhibit the essential enzyme acetylcholinesterase (AChE) by organophosphorylating the catalytic serine residue. Nucleophiles, such as oximes, are used as antidotes as they can reactivate and restore the function of the inhibited enzyme. The oxime HI-6 shows a notably low activity on tabun adducts but can effectively reactivate adducts of cyclosarin and Russian VX. To examine the structural basis for the pronounced substrate specificity of HI-6, we determined the binary crystal structures of Mus musculus AChE (mAChE) conjugated by cyclosarin and Russian VX and found a conformational mobility of the side chains of Phe338 and His447. The interaction between HI-6 and tabun-adducts of AChE were subsequently investigated using a combination of time resolved fluorescence spectroscopy and X-ray crystallography. Our findings show that HI-6 binds to tabun inhibited Homo sapiens AChE (hAChE) with an IC50 value of 300μM and suggest that the reactive nucleophilic moiety of HI-6 is excluded from the phosphorus atom of tabun. We propose that a conformational mobility of the side-chains of Phe338 and His447 is a common feature in nerve-agent adducts of AChE. We also suggest that the conformational mobility allow HI-6 to reactivate conjugates of cyclosarin and Russian VX while a reduced mobility in tabun conjugated AChE results in steric hindrance that prevents efficient reactivation.

  7. COOH-terminal collagen Q (COLQ) mutants causing human deficiency of endplate acetylcholinesterase impair the interaction of ColQ with proteins of the basal lamina.

    Arredondo, Juan; Lara, Marian; Ng, Fiona; Gochez, Danielle A; Lee, Diana C; Logia, Stephanie P; Nguyen, Joanna; Maselli, Ricardo A

    2014-05-01

    Collagen Q (ColQ) is a key multidomain functional protein of the neuromuscular junction (NMJ), crucial for anchoring acetylcholinesterase (AChE) to the basal lamina (BL) and accumulating AChE at the NMJ. The attachment of AChE to the BL is primarily accomplished by the binding of the ColQ collagen domain to the heparan sulfate proteoglycan perlecan and the COOH-terminus to the muscle-specific receptor tyrosine kinase (MuSK), which in turn plays a fundamental role in the development and maintenance of the NMJ. Yet, the precise mechanism by which ColQ anchors AChE at the NMJ remains unknown. We identified five novel mutations at the COOH-terminus of ColQ in seven patients from five families affected with endplate (EP) AChE deficiency. We found that the mutations do not affect the assembly of ColQ with AChE to form asymmetric forms of AChE or impair the interaction of ColQ with perlecan. By contrast, all mutations impair in varied degree the interaction of ColQ with MuSK as well as basement membrane extract (BME) that have no detectable MuSK. Our data confirm that the interaction of ColQ to perlecan and MuSK is crucial for anchoring AChE to the NMJ. In addition, the identified COOH-terminal mutants not only reduce the interaction of ColQ with MuSK, but also diminish the interaction of ColQ with BME. These findings suggest that the impaired attachment of COOH-terminal mutants causing EP AChE deficiency is in part independent of MuSK, and that the COOH-terminus of ColQ may interact with other proteins at the BL.

  8. Changes in Behavior and Brain Acetylcholinesterase Activity in Mosquito Fish, Gambusia affinis in Response to the Sub-Lethal Exposure to Chlorpyrifos

    R. Nageswara Rao

    2005-12-01

    Full Text Available Sub-lethal studies of chlorpyrifos, O,O-diethyl-O-(3,5,6-trichloro-2-pyridyl phosphorothioate on mosquito fish, Gambusia affinis were carried out in vivo, for 20 days to assess the locomotor behavior in relation to bioaccumulation and interaction with a targeted enzyme, acetylcholinesterase (AChE, EC: 3.1.1.7. Fish exposed to sub-lethal concentration of 60 Ag/L (1/5 of LC50 were under stress, and reduced their locomotor behavior like distance travelled per unit time (m/min and swimming speed (cm/sec with respect to the length of exposure. The alteration in locomotor behavior of fish may be due to an accumulation of acetylcholine (ACh, a neurotransmitter at synaptic junctions, due to the inhibition of AChE enzyme activity (40 to 55% in brain and also bioaccumulation of the toxicant in different parts of fish. The bioaccumulation values indicated that the accumulation of chlorpyrifos was maximum in viscera followed by head and body. The average bioconcentration values are 0.109, 0.009 and 0.004 Ag/g for viscera, head and body with depuration rates of 2.24, 1.69 and 0.39 ng/h respectively. It is evident from the results that the sub-lethal concentration [1/5 of LC50; equivalent to Lowest Observed Effect Concentration (LOEC] of chlorpyrifos can able to alter the locomotor behavior of G. affinis in relation to the length of exposure. The findings revealed that the locomotor activity of test organism could be considered as a suitable marker to evaluate the affect of toxicant even at LOEC levels.

  9. Aphicidal Activity of Illicium verum Fruit Extracts and Their Effects on the Acetylcholinesterase and Glutathione S-transferases Activities in Myzus persicae (Hemiptera: Aphididae).

    Zhou, Ben-Guo; Wang, Sa; Dou, Ting-Ting; Liu, Su; Li, Mao-Ye; Hua, Ri-Mao; Li, Shi-Guang; Lin, Hua-Feng

    2016-01-01

    This study aims to explore the aphicidal activity and underlying mechanism of Illicium verum Hook. f. that is used as both food and medicine. The contact toxicity of the extracts from I. verum fruit with methyl alcohol (MA), ethyl acetate (EA), and petroleum ether (PE) against Myzus persicae (Sulzer), and the activities of acetylcholinesterase (AChE) and glutathione S-transferases (GSTs) of M. persicae after contact treatment were tested. The results showed that MA, EA, and PE extracts of 1.000 mg/l caused, respectively, M. persicae mortalities of 68.93%, 89.95% and 74.46%, and the LC50 of MA, EA, and PE extracts were 0.31, 0.14 and 0.27 mg/l at 72 h after treatment, respectively; the activities of AChE and GSTs in M. persicae were obviously inhibited by the three extracts, as compared with the control, with strong dose and time-dependent effects, the inhibition rates on the whole reached more than 50.00% at the concentration of 1.000 mg/l at 72 h after treatment. The inhibition of the extracts on AChE and GSTs activities (EA extract > PE extract > MA extract) were correlated with theirs contact toxic effects, so it is inferred that the decline of the metabolic enzymes activities may be one of important reasons of M. persicae death. The study results suggested that I. verum extracts have potential as a eco-friendly biopesticide in integrated pest management against M. persicae.

  10. Application of a dynamic in vitro model with real-time determination of acetylcholinesterase activity for the investigation of tabun analogues and oximes.

    Worek, Franz; Herkert, Nadja M; Koller, Marianne; Thiermann, Horst; Wille, Timo

    2015-12-25

    Tabun-inhibited acetylcholinesterase (AChE) is rather resistant towards reactivation by oximes in vitro while in vivo experiments showed some protection of animals poisoned by this chemical warfare nerve agent after treatment with an oxime and atropine. In addition, AChE inhibited by close tabun analogues, N,N-diethyltabun and N,N-di-n-propyltabun was completely resistant towards reactivation by oximes. In order to get more insight into potential mechanisms of this oxime resistance experiments with these toxic agents and the oximes obidoxime, 2-PAM, MMB-4 and HI-6 were performed utilizing a dynamic model with real-time determination of AChE activity. This experimental setup allowed the investigation of reactivation with minimized side reactions. The determined reactivation constants with tabun-inhibited human AChE were in good agreement with previously reported constants determined with a static model. N,N-diethyl- and N,N-di-n-propyltabun-inhibited human AChE could not be reactivated by oximes which indicates that the inadequate oxime effect was not due to re-inhibition by phosphonyloximes. Additional experiments with tabun-inhibited human and Rhesus monkey AChE revealed that no reactivation occurred with HI-6. These data give further support to the assumption that an interaction of tabun with residues in the active site gorge of AChE prevents effective reactivation by oximes, a mechanism which may also be the reason for the total oxime resistance of N,N-diethyl- and N,N-di-n-propyltabun-inhibited human AChE.

  11. Nicotinic and muscarinic agonists and acetylcholinesterase inhibitors stimulate a common pathway to enhance GluN2B-NMDAR responses

    Ishibashi, Masaru; Yamazaki, Yoshihiko; Miledi, Ricardo; Sumikawa, Katumi

    2014-01-01

    Nicotinic and muscarinic ACh receptor agonists and acetylcholinesterase inhibitors (AChEIs) can enhance cognitive function. However, it is unknown whether a common signaling pathway is involved in the effect. Here, we show that in vivo administration of nicotine, AChEIs, and an m1 muscarinic (m1) agonist increase glutamate receptor, ionotropic, N-methyl D-aspartate 2B (GluN2B)-containing NMDA receptor (NR2B-NMDAR) responses, a necessary component in memory formation, in hippocampal CA1 pyramidal cells, and that coadministration of the m1 antagonist pirenzepine prevents the effect of cholinergic drugs. These observations suggest that the effect of nicotine is secondary to increased release of ACh via the activation of nicotinic ACh receptors (nAChRs) and involves m1 receptor activation through ACh. In vitro activation of m1 receptors causes the selective enhancement of NR2B-NMDAR responses in CA1 pyramidal cells, and in vivo exposure to cholinergic drugs occludes the in vitro effect. Furthermore, in vivo exposure to cholinergic drugs suppresses the potentiating effect of Src on NMDAR responses in vitro. These results suggest that exposure to cholinergic drugs maximally stimulates the m1/guanine nucleotide-binding protein subunit alpha q/PKC/proline-rich tyrosine kinase 2/Src signaling pathway for the potentiation of NMDAR responses in vivo, occluding the in vitro effects of m1 activation and Src. Thus, our results indicate not only that nAChRs, ACh, and m1 receptors are on the same pathway involving Src signaling but also that NR2B-NMDARs are a point of convergence of cholinergic and glutamatergic pathways involved in learning and memory. PMID:25114227

  12. The effects of rivastigmine plus selegiline on brain acetylcholinesterase, (Na+, K+-, Mg2+-ATPase activities, antioxidant status, and learning performance of aged rats

    Haris Carageorgiou

    2008-09-01

    Full Text Available Haris Carageorgiou1, Antonios C Sideris1, Ioanna Messari1, Chrissoula I Liakou1, Stylianos Tsakiris21Department of Pharmacology, 2Department of Physiology, Medical School, University of Athens, Athens, GreeceAbstract: We investigated the effects of rivastigmine (a cholinesterase inhibitor and selegiline ((-deprenyl, an irreversible inhibitor of monoamineoxidase-B, alone and in combination, on brain acetylcholinesterase (AChE, (Na+, K+-, Mg2+-ATPase activities, total antioxidant status (TAS, and learning performance, after long-term drug administration in aged male rats. The possible relationship between the biochemical and behavioral parameters was evaluated.Methods: Aged rats were treated (for 36 days with rivastigmine (0.3 mg/kg rat/day ip, selegiline (0.25 mg/kg rat/day im, rivastigmine plus selegiline in the same doses and way of administration as separately. Aged and adult control groups received NaCl 0.9% 0.5 ml ip.Results: TAS was lower in aged than in adult rats, rivastigmine alone does not affect TAS, decreases AChE activity, increases (Na+, K+-ATPase and Mg2+-ATPase activity of aged rat brain and improves cognitive performance. Selegiline alone decreases free radical production and increases AChE activity and (Na+, K+-ATPase activity, improving cognitive performance as well. In the combination: rivastigmine seems to cancel selegiline action on TAS and AChE activity, while it has additive effect on (Na+, K+-ATPase activity. In the case of Mg2+-ATPase selegiline appears to attenuate rivastigmine activity. No statistically significant difference was observed in the cognitive performance.Conclusion: Reduced TAS, AChE activity and learning performance was observed in old rats. Both rivastigmine and selesiline alone improved performance, although they influenced the biochemical parameters in a different way. The combination of the two drugs did not affect learning performance.Keywords: aged rat, brain enzymes, TAS, learning, rivastigmine

  13. Phytoestrogens genistein and daidzin enhance the acetylcholinesterase activity of the rat pheochromocytoma cell line PC12 by binding to the estrogen receptor.

    Isoda, Hiroko; Talorete, Terence P N; Kimura, Momoko; Maekawa, Takaaki; Inamori, Yuhei; Nakajima, Nobuyoshi; Seki, Humitake

    2002-11-01

    Some compounds derived from plants have been known to possess estrogenic properties and can thus alter the physiology of higher organisms. Genistein and daidzin are examples of these phytoestrogens, which have recently been the subject of extensive research. In this study, genistein and daidzin were found to enhance the acetylcholinesterase (AChE) activity of the rat neuronal cell line PC12 at concentrations as low as 0.08 muM by binding to the estrogen receptor (ER). Results have shown that this enhancement was effectively blocked by the known estrogen receptor antagonist tamoxifen, indicating the involvement of the ER in AChE induction. That genistein and daidzin are estrogenic were confirmed in a cell proliferation assay using the human breast cancer cell line MCF7. This proliferation was also blocked by tamoxifen, again indicating the involvement of the ER. On the other hand, incubating the PC12 cells in increasing concentrations of 17 beta-estradiol (E2) did not lead to enhanced AChE activity, even in the presence of genistein or daidzin. This suggests that mere binding of an estrogenic compound to the ER does not necessarily lead to enhanced AChE activity. Moreover, the effect of the phytoestrogens on AChE activity cannot be expressed in the presence of E2 since they either could not compete with the natural ligand in binding to the ER or that E2 down-regulates its own receptor. This study clearly suggests that genistein and daidzin enhance AChE activityin PC12 cells by binding to the ER; however, the actual mechanism of enhancement is not known.

  14. 植物寄生线虫乙酰胆碱酯酶结构与功能研究进展%Research progress on structure and function of acetylcholinesterase in plant parasitic nematodes

    吴青松; 彭德良; 黄文坤

    2016-01-01

    乙酰胆碱酯酶通过水解神经递质乙酰胆碱使得神经信号能够在生物体内进行正常的传递,从而有效调节正常的肌肉活动,在生物体神经传导的过程中发挥着重要作用。植物寄生线虫乙酰胆碱酯酶具有由多种基因编码的不同分子型,在线虫化感、运动、取食、抗药性等多个方面承担着不同的功能。本文简要综述了植物寄生线虫乙酰胆碱酯酶分子型、基因结构、基因功能、组织表达及其在线虫抗药性中的作用等方面的研究进展。%The acetylcholinesterase hydrolyzes the concerned neurotransmitter acetylcholine to ensure the normal delivery of nerve signals in the organism and regulates the normal muscle activity,which plays an important role in the process of biological nerve conduction.Acetylcholinesterases of plant parasitic nematodes exist in diverse mo-lecular forms,which are encoded by different genes.Those forms undertake different functions such as chemore-ceptivity,movement,feeding,and resistance of nematicides.This review gives a brief introduction on the ad-vance of molecular forms,structure,function,histochemical expression and nematicidal resistance of acetylcho-linesterase in plant parasitic nematodes.

  15. Design of a potent reactivator of tabun-inhibited acetylcholinesterase--synthesis and evaluation of (E)-1-(4-carbamoylpyridinium)-4-(4-hydroxyiminomethylpyridinium)-but-2-ene dibromide (K203).

    Musilek, Kamil; Jun, Daniel; Cabal, Jiri; Kassa, Jiri; Gunn-Moore, Frank; Kuca, Kamil

    2007-11-01

    Acetylcholinesterase reactivators are crucial antidotes for the treatment of organophosphate intoxication. Among the organophosphates, with the exception of soman, tabun (GA) intoxications are the least responsive to treatment with commercially available therapeutics. A rational design was used to increase reactivation ability and decrease the toxicity of the novel reactivator. (E)-1-(4-carbamoylpyridinium)-4-(4-hydroxyiminomethylpyridinium)-but-2-ene dibromide (K203) has better properties than previously tested compounds in vitro and, therefore, is a potential candidate for the treatment of GA intoxication in vivo.

  16. Seleção de plantas com atividade anticolinasterase para tratamento da doença de Alzheimer Screening for acetylcholinesterase inhibitors from plants to treat Alzheimer's disease

    Maria Teresa Salles Trevisan

    2003-05-01

    Full Text Available Alzheimer's disease (AD is a neurodegenerative disease characterized by cognite impairment and personality changes. The development of drugs for the treatment of the cognitive deficits of AD has focused on agents which counteract loss in cholinergic activities. These symptons of AD have been successfully treated with acetylcholinesterase (AchE inhibitors (eg. galanthamine. There still is great interest in finding better AchE inhibitors. We use Ellmann's microplate assay and silica gel thin-layer chromatography (TLC to screen natural products from plants as new sources of AchE inhibitors.

  17. Study on Immobilization of Acetylcholinesterase with Filter Paper Coated with Chitosan%滤纸壳聚糖膜固定乙酰胆碱酯酶的研究

    郭尽力; 姜爱莉; 于贞; 郑舒文

    2012-01-01

    [目的]探索滤纸壳聚糖膜固定乙酰胆碱酯酶( AChE)的最佳条件.[方法]以滤纸壳聚糖膜为我体,戊二醛为交联剂,牛血清白蛋白( BSA)为保护剂,进行AChE的固定.并对固定化酶的理化性质进行研究.[结果]固定AChE的最佳条件为将50μl150 U/mlAChE液,50 μl 5%(V/V)戊二醛溶液,100μl1%(W/W) BSA,pH 8.0的0.2 mol/L的PBS缓冲液配制成1 ml酶液,滤纸壳聚糖膜浸于该酶液4℃固定8h.固定化酶的最适反应温度为37℃,最适pH为8.0,能够重复利用4次以上.[结论]该研究为利用AChE快速检测蔬菜水果中有机磷农药残留提供了理论依据.%[Objective] The aim was to explore the optimum immobilized conditions of acetylcholinesterase on filter paper coated with chitosan. [Method] Acetylcholinesterase was immobilized on filter paper coated with chitosan using glutaraldehyde as cross-linking reagent, bovine serum albumin as protective agent. And the physical and chemical properties of the immobilized enzyme were studied. [Result] The optimal immobilized conditions were as follows: 1 ml solution was prepared with 50 μl 150 U/ml acetylcholinesterase solution, 50 μl 5% ( V/V) glutaraldehyde, 100 μl 1% (W/W) BSA and 0.2 mol/L phosphate buffer(pH 8.0) , and then the filter paper coated with chitosan was immersed for 8 h at 4 ℃.. The optimum temperature of the immobilized acetylcholinesterase was 37 ℃ , the optimum pH was 8.0, and its could be reused four times. [ Conclusion] The study provides a theory basis for rapid determination of organophosphorus pesticide residues in vegetables and fruits.

  18. 蚊虫乙酰胆碱酯酶的真核表达、纯化及活性测定%Expression and purification of acetylcholinesterase from culex by Bac-to-Bac baculovirus system and the activity determination

    谭烽; 兰文升; 崔峰; 乔传令; 陈雯莉

    2012-01-01

    利用Trizol法从尖音库蚊中提取总RNA,构建cDNA文库,并克隆出乙酰胆碱酯酶外显子序列;利用Bac-to-Bac杆状病毒表达系统对蚊虫乙酰胆碱酯酶进行真核表达,并利用Ni-琼脂糖对酶进行纯化.采用SDS-PAGE对纯化产物进行检测,结果表明得到了纯度较高的乙酰胆碱酯酶.参照Ellman法对酶的活性进行测定,结果显示纯酶的活力为2.219×10-4mol/(min·g).%The residues of the high toxic organophosphorous can cause chronic poisoning. At present, the detection of organophosphorous residue needs complicated operation, time consuming and high cost. Here,we harvested total RNA of mosquito by Trizol methods, constructed cDNA library, and got the exon of acetylcholinesterase. The acetylcholinesterase from culex was expressed by Bac-to-Bac system, then the enzyme was purified using Ni-sepharose. The crude and purified enzyme was tested and verified by SDS-PAGE. The enzyme activity was determined by Ellman methods. It will be of great significance to biosensors in organophosphorous pesticides detection.

  19. No significant effects of single intravenous, single oral and subchronic oral administration of acetylcholinesterase inhibitors on striatal [{sup 123}I]FP-CIT binding in rats

    Knol, R.J.J.; Booij, J. [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Center, Amsterdam (Netherlands); Graduate School of Neurosciences, Amsterdam (Netherlands); Bruin, K. de; Eck-Smit, B.L.F. van [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Center, Amsterdam (Netherlands)

    2008-03-15

    [{sup 123}I]FP-CIT SPECT is a valuable diagnostic tool to discriminate Lewy body dementia from Alzheimer's dementia. To date, however, it is uncertain whether the frequently used acetylcholinesterase inhibitors (AChEIs) by demented patients, have an effect on [{sup 123}I]FP-CIT binding to dopamine transporters (DATs). Earlier animal studies showed a decline of DAT availability after acute intravenous injection of AChEIs. The aim of this study was to investigate effects of single intravenous, single oral and subchronic oral administration of AChEIs on DAT availability in the rat brain as measured by [{sup 123}I]FP-CIT. Biodistribution studies were performed in Wistar rats (n = 5-16 per group). Before [{sup 123}I]FP-CIT injection, rats were injected intravenously with a single dose of the AChEI rivastigmine (2.5 mg/kg body weight) or donepezil (0.5 mg/kg), the DAT-blocker methylphenidate (10 mg/kg) or saline. A second group was orally treated with a single dose of rivastigmine or donepezil (2.5 mg/kg), methylphenidate (10 mg/kg) or saline before injection of [{sup 123}I]FP-CIT. Studies were also performed in rats that were orally treated during 14 consecutive days with either rivastigmine (1 mg/kg daily), donepezil (1.5 mg/kg daily), methylphenidate (2.5 mg/kg) or saline. Brain parts were assayed in a gamma counter, and specific striatum/cerebellum ratios were calculated for the [{sup 123}I]FP-CIT binding to DATs. No significant effects of either single intravenous, single oral or subchronic oral administration of AChEIs on striatal FP-CIT binding could be detected. Single pretreatment with methylphenidate resulted in an expected significantly lower striatal FP-CIT binding. We conclude that in rats, single intravenous and single or subchronic oral administration of the tested AChEIs does not lead to an important alteration of [{sup 123}I]FP-CIT binding to striatal DATs. Therefore, it is unlikely that these drugs will induce large effects on the interpretation of

  20. Binding of 2-[{sup 18}F]fluoro-CP-118,954 to mouse acetylcholinesterase: microPET and ex vivo Cerenkov luminescence imaging studies

    Kim, Dong Hyun [Center for Molecular and Cellular Imaging, Samsung Biomedical Research Institute, 50 Ilwon-dong, Kangnam-ku, Seoul 135-710 (Korea, Republic of); Choe, Yearn Seong, E-mail: ysnm.choe@samsung.co [Center for Molecular and Cellular Imaging, Samsung Biomedical Research Institute, 50 Ilwon-dong, Kangnam-ku, Seoul 135-710 (Korea, Republic of); Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Kangnam-ku, Seoul 135-710 (Korea, Republic of); Choi, Joon Young [Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Kangnam-ku, Seoul 135-710 (Korea, Republic of); Lee, Kyung-Han; Kim, Byung-Tae [Center for Molecular and Cellular Imaging, Samsung Biomedical Research Institute, 50 Ilwon-dong, Kangnam-ku, Seoul 135-710 (Korea, Republic of); Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Kangnam-ku, Seoul 135-710 (Korea, Republic of)

    2011-05-15

    Acetylcholinesterase (AChE) has been an important cholinergic factor for the diagnosis of Alzheimer's disease (AD), because of reduced AChE activity in the postmortem brains of AD patients. We previously developed 5,7-dihydro-3-(2-(1-(2-[{sup 18}F]fluorobenzyl)-4-piperidinyl)ethyl)-6H-pyrrolo (3,2,f)-1,2-benzisoxazol-6-one (2-[{sup 18}F]fluoro-CP-118,954) for in vivo studies of AChE in mice. In the present study, we automated the synthesis of 2-[{sup 18}F]fluoro-CP-118,954 for the routine use and evaluated the radioligand by microPET and ex vivo Cerenkov luminescence imaging of mouse AChE. 4-[{sup 18}F]Fluoro-donepezil, another AChE inhibitor, was used for comparison. Automated syntheses of 2-[{sup 18}F]fluoro-CP-118,954 and 4-[{sup 18}F]fluoro-donepezil resulted in high radiochemical yields (25-33% and 30-40%) and high specific activity (27.1-35.4 and 29.7-37.3 GBq/{mu}mol). Brain microPET images of two ICR mice injected with 2-[{sup 18}F]fluoro-CP-118,954 demonstrated high uptake in the striatum (ROI analysis: 5.1 %ID/g for the first 30 min and 4.1 %ID/g for another 30 min), and a blocking study with injection of CP-118,954 into one of the mice at 30 min after radioligand injection led to complete blocking of radioligand uptake in the striatum (ROI analysis: 1.9 %ID/g), whereas {sup 18}F-labeled donepezil did not show specific uptake in the striatum. In another set of experiments, the brain tissues (striatum, parietal cortex, frontal cortex and cerebellum) were excised after brain microPET/CT imaging of mouse injected with 2-[{sup 18}F]fluoro-CP-118,954, and a high striatal uptake was also detected in ex vivo optical and microPET images (ROI analysis: 1.4 %ID/g) and in {gamma}-counting data (2.1 %ID/g at 50 min post-injection) of the brain tissues. Taken together, these results demonstrated that 2-[{sup 18}F]fluoro-CP-118,954 specifically binds to AChE in mouse brains.

  1. Resolving pathways of interaction of mipafox and a sarin-analog with human acetylcholinesterase by kinetics, mass spectrometry and molecular modeling approaches

    Mangas, I; Taylor, P; Vilanova, E; Estévez, J; Franca, T; Radić, Z

    2016-01-01

    The hydroxyl oxygen of the catalytic triad serine in the active center of serine hydrolase acetylcholinesterase (AChE) attacks organophosphorus compounds (OPs) at the phosphorus atom to displace the primary leaving group and to form a covalent bond. Inhibited AChE can be reactivated by cleavage of the Ser-phosphorus bond either spontaneously or through a reaction with nucleophilic agents, such as oximes. At the same time, the inhibited AChE adduct can lose part of the molecule by progressive dealkylation over time in a process called aging. Reactivation of the aged enzyme has not yet been demonstrated. Here our goal was to study oxime reactivation and aging reactions of human AChE inhibited by mipafox or a sarin analog (Flu-MPs, fluorescent methylphosphonate). Progressive reactivation was observed after Flu-MPs inhibition using oxime 2-PAM. However, no reactivation was observed after mipafox inhibition with 2-PAM or the more potent oximes used. A peptide mass fingerprinted mass spectrometry (MS) method, which clearly distinguished the peptide with the active serine (active center peptide, ACP) of the human AChE adducted with OPs, was developed by MALDI-TOF and MALDI-TOF-TOF. The ACP was detected with a diethyl phosphorylated adduct after paraoxon inhibition, and with an isopropylmethyl phosphonylated and a methyl phosphonylated adduct after Flu-MPs inhibition and subsequent aging. Nevertheless, nonaged nonreactivated complexes were seen after mipafox inhibition and incubation with oximes, where MS data showed an ACP with an NN diidopropyl phosphoryl adduct. The kinetic experiments showed no reactivation of activity. The computational molecular model analysis of the mipafox-inhibited hAChE plots of energy versus distance between the atoms separated by dealkylation showed a high energy demand, thus little aging probability. However with Flu-MPs and DFP, where aging was observed in our MS data and in previously published crystal structures, the energy demand

  2. Resolving pathways of interaction of mipafox and a sarin analog with human acetylcholinesterase by kinetics, mass spectrometry and molecular modeling approaches.

    Mangas, I; Taylor, P; Vilanova, E; Estévez, J; França, T C C; Komives, E; Radić, Z

    2016-03-01

    The hydroxyl oxygen of the catalytic triad serine in the active center of serine hydrolase acetylcholinesterase (AChE) attacks organophosphorus compounds (OPs) at the phosphorus atom to displace the primary leaving group and to form a covalent bond. Inhibited AChE can be reactivated by cleavage of the Ser-phosphorus bond either spontaneously or through a reaction with nucleophilic agents, such as oximes. At the same time, the inhibited AChE adduct can lose part of the molecule by progressive dealkylation over time in a process called aging. Reactivation of the aged enzyme has not yet been demonstrated. Here, our goal was to study oxime reactivation and aging reactions of human AChE inhibited by mipafox or a sarin analog (Flu-MPs, fluorescent methylphosphonate). Progressive reactivation was observed after Flu-MPs inhibition using oxime 2-PAM. However, no reactivation was observed after mipafox inhibition with 2-PAM or the more potent oximes used. A peptide fingerprinted mass spectrometry (MS) method, which clearly distinguished the peptide with the active serine (active center peptide, ACP) of the human AChE adducted with OPs, was developed by MALDI-TOF and MALDI-TOF/TOF. The ACP was detected with a diethyl-phosphorylated adduct after paraoxon inhibition, and with an isopropylmethyl-phosphonylated and a methyl-phosphonylated adduct after Flu-MPs inhibition and subsequent aging. Nevertheless, nonaged nonreactivated complexes were seen after mipafox inhibition and incubation with oximes, where MS data showed an ACP with an NN diisopropyl phosphoryl adduct. The kinetic experiments showed no reactivation of activity. The computational molecular model analysis of the mipafox-inhibited hAChE plots of energy versus distance between the atoms separated by dealkylation showed a high energy demand, thus little aging probability. However, with Flu-MPs and DFP, where aging was observed in our MS data and in previously published crystal structures, the energy demand calculated

  3. Morphological alterations and acetylcholinesterase and monoamine oxidase inhibition in liver of zebrafish exposed to Aphanizomenon flos-aquae DC-1 aphantoxins

    Zhang, De Lu, E-mail: deluzh@163.com [Department of Lifescience and Biotechnology, School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070 (China); Zhang, Jing [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Hu, Chun Xiang, E-mail: cxhu@ihb.ac.cn [Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072 (China); Wang, Gao Hong; Li, Dun Hai; Liu, Yong Ding [Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072 (China)

    2014-12-15

    Highlights: • Aphantoxins induced zebrafish hepatic physiological and morphological changes. • AChE and MAO inhibition reflected abnormality of neurotransmitter inactivation. • ROS advance and T-AOC reduction suggested oxidative stress. • ALT, AST, histological and ultrastructural alterations indicated hepatic damage. - Abstract: Aphanizomenon flos-aquae is a cyanobacterium that produces neurotoxins or paralytic shellfish poisons (PSPs) called aphantoxins, which present threats to environmental safety and human health via eutrophication of water bodies worldwide. Although the molecular mechanisms of this neurotoxin have been studied, many questions remain unsolved, including those relating to in vivo hepatic neurotransmitter inactivation, physiological detoxification and histological and ultrastructural alterations. Aphantoxins extracted from the natural strain of A. flos-aquae DC-1 were analyzed by high-performance liquid chromatography. The main components were gonyautoxins 1 and 5 (GTX1, GTX5) and neosaxitoxin (neoSTX), which comprised 34.04%, 21.28%, and 12.77% respectively. Zebrafish (Danio rerio) were exposed intraperitoneally to 5.3 or 7.61 μg STX equivalents (eq)/kg (low and high doses, respectively) of A. flos-aquae DC-1 aphantoxins. Morphological alterations and changes in neurotransmitter conduction functions of acetylcholinesterase (AChE) and monoamine oxidase (MAO) in zebrafish liver were detected at different time points 1–24 h post-exposure. Aphantoxin significantly enhanced hepatic alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and histological and ultrastructural damage in zebrafish liver at 3–12 h post-exposure. Toxin exposure increased the reactive oxygen species content and reduced total antioxidative capacity in zebrafish liver, suggesting oxidative stress. AChE and MAO activities were significantly inhibited, suggesting neurotransmitter inactivation/conduction function abnormalities in zebrafish

  4. Slow-binding inhibition of acetylcholinesterase by an alkylammonium derivative of 6-methyluracil: mechanism and possible advantages for myasthenia gravis treatment.

    Kharlamova, Alexandra D; Lushchekina, Sofya V; Petrov, Konstantin A; Kots, Ekaterina D; Nachon, Florian; Villard-Wandhammer, Marielle; Zueva, Irina V; Krejci, Eric; Reznik, Vladimir S; Zobov, Vladimir V; Nikolsky, Evgeny E; Masson, Patrick

    2016-05-01

    Inhibition of human AChE (acetylcholinesterase) and BChE (butyrylcholinesterase) by an alkylammonium derivative of 6-methyluracil, C-547, a potential drug for the treatment of MG (myasthenia gravis) was studied. Kinetic analysis of AChE inhibition showed that C-547 is a slow-binding inhibitor of type B, i.e. after formation of the initial enzyme·inhibitor complex (Ki=140 pM), an induced-fit step allows establishment of the final complex (Ki*=22 pM). The estimated koff is low, 0.05 min(-1) On the other hand, reversible inhibition of human BChE is a fast-binding process of mixed-type (Ki=1.77 μM; Ki'=3.17 μM). The crystal structure of mouse AChE complexed with C-547 was solved at 3.13 Å resolution. The complex is stabilized by cation-π, stacking and hydrogen-bonding interactions. Molecular dynamics simulations of the binding/dissociation processes of C-547 and C-35 (a non-charged analogue) to mouse and human AChEs were performed. Molecular modelling on mouse and human AChE showed that the slow step results from an enzyme conformational change that allows C-547 to cross the bottleneck in the active-site gorge, followed by formation of tight complex, as observed in the crystal structure. In contrast, the related non-charged compound C-35 is not a slow-binding inhibitor. It does not cross the bottleneck because it is not sensitive to the electrostatic driving force to reach the bottom of the gorge. Thus C-547 is one of the most potent and selective reversible inhibitors of AChE with a long residence time, τ=20 min, longer than for other reversible inhibitors used in the treatment of MG. This makes C-547 a promising drug for the treatment of this disease.

  5. Factors associated with response to acetylcholinesterase inhibition in dementia: a cohort study from a secondary mental health care case register in london.

    Gayan Perera

    Full Text Available Acetylcholinesterase inhibitors (AChEIs are widely used to delay cognitive decline in Alzheimer's disease. Observational studies in routine clinical practice have shown cognitive improvement in some groups of patients receiving these agents but longitudinal trajectories before and after AChEI initiation have not previously been considered.To compare trajectories of cognitive function before and after AChEI initiation and investigate predictors of these differences.A retrospective longitudinal study was constructed using data from 2460 patients who received AChEIs and who had routine data on cognitive function (Mini-Mental State Examination; MMSE before and after AChEI initiation. Longitudinal MMSE change was modelled using three-piece linear mixed models with the following segments: 0-12 months prior to AChEI initiation, 0-6 months and 6-36 months after initiation.MMSE decline was reversed (in that the slope was improved by an average 4.2 units per year, 95% CI 3.5-4.8 during the 6-month period following AChEI initiation compared with the slope in the one year period before AChEI initiation. The slope in the period from 6-36 months following AChEI initiation returned to the pre-initiation downward trajectory. The differences in slopes in the 1 year period prior to AChEI initiation and in the 6 months after initiation were smaller among those with higher MMSE scores at the time of AChEI initiation, among those who received a vascular dementia diagnosis at any point, and among those receiving antipsychotic agents.In this naturalistic observational study, changes in cognitive trajectories around AChEI initiation were similar to those reported in randomised controlled trials. The magnitude of the difference in slopes between the 1 year period prior to AChEI initiation and the 6 month period after AChEI initiation was related to level of cognitive function at treatment initiation, vascular comorbidity and antipsychotic use.

  6. Factors Associated with Response to Acetylcholinesterase Inhibition in Dementia: A Cohort Study from a Secondary Mental Health Care Case Register in London

    Perera, Gayan; Khondoker, Mizanur; Broadbent, Matthew; Breen, Gerome; Stewart, Robert

    2014-01-01

    Background Acetylcholinesterase inhibitors (AChEIs) are widely used to delay cognitive decline in Alzheimer's disease. Observational studies in routine clinical practice have shown cognitive improvement in some groups of patients receiving these agents but longitudinal trajectories before and after AChEI initiation have not previously been considered. Objectives To compare trajectories of cognitive function before and after AChEI initiation and investigate predictors of these differences. Method A retrospective longitudinal study was constructed using data from 2460 patients who received AChEIs and who had routine data on cognitive function (Mini-Mental State Examination; MMSE) before and after AChEI initiation. Longitudinal MMSE change was modelled using three-piece linear mixed models with the following segments: 0–12 months prior to AChEI initiation, 0–6 months and 6–36 months after initiation. Results MMSE decline was reversed (in that the slope was improved by an average 4.2 units per year, 95% CI 3.5–4.8) during the 6-month period following AChEI initiation compared with the slope in the one year period before AChEI initiation. The slope in the period from 6–36 months following AChEI initiation returned to the pre-initiation downward trajectory. The differences in slopes in the 1 year period prior to AChEI initiation and in the 6 months after initiation were smaller among those with higher MMSE scores at the time of AChEI initiation, among those who received a vascular dementia diagnosis at any point, and among those receiving antipsychotic agents. Conclusion In this naturalistic observational study, changes in cognitive trajectories around AChEI initiation were similar to those reported in randomised controlled trials. The magnitude of the difference in slopes between the 1 year period prior to AChEI initiation and the 6 month period after AChEI initiation was related to level of cognitive function at treatment initiation, vascular comorbidity and

  7. In-vitro screening of acetylcholinesterase inhibitory activity of extracts from Palestinian indigenous flora in relation to the treatment of Alzheimer’s disease

    Mohammed Saleem Ali-Shtayeh

    2014-09-01

    Full Text Available Background: Cholinesterase inhibitory therapy serves as a strategy for the treatment of Alzheimer’s disease (AD. Several acetylcholinesterase inhibitors (AChEIs are used for the symptomatic treatment of AD. These compounds have been reported to have adverse effects, including gastrointestinal disturbances. This study was therefore partly aimed at investigating in vitro possible AChEIs in herbal medicines traditionally used in Palestine to treat cognitive disorders, and to point out the role of these plants as potential sources for development of newly potent and safe natural therapeutic agents of AD. Assay of AChE activity plays an important role in vitro characterization of drugs including potential treatments for AD. The most widely used method, is based on Ellman’s method. The reactant used in this method shows chemical reactivity with oxime antidots and thiol leading to false positive reactions. A new alternative assay could be of high interest. Methods: The effect on AChE activity of 92 extracts of 47 medicinal plants were evaluated using a new micro-well plate AChE activity (NA-FB and Ellman’s assays. In addition, antioxidant activity using DPPH was determined. Results: The main advantages of the new method (NA-FB is that the colorimetric change is better observable visually allowing spectrophotometric as well as colorimetric assay, and does not show any chemical reactivity with thiol. 67.4% and 37% of extracts inhibited AChE by >50% using the NA-FB and Ellman’s assays, respectively. Using NA-FB assay, 84 extracts interacted reversibly with the enzyme, of which Mentha spicata (94.8%, Foeniculum vulgare (89.81, and Oxalis pes-caprae (89.21 were most potent, and 8 showed irreversible inhibition of which leaves of Lupinus pilosus (92.02% were most active. Antioxidant activity was demonstrated by 73 extracts Majorana syriaca (IC50 0.21mg/ml, and Rosmarinus officinalis (0.38 were the most active. Conclusions: NA-FB assay has shown to be

  8. Invokana (Canagliflozin) as a dual inhibitor of acetylcholinesterase and sodium glucose co-transporter 2: advancement in Alzheimer's disease- diabetes type 2 linkage via an enzoinformatics study.

    Rizvi, Syed M D; Shakil, Shahnawaz; Biswas, Deboshree; Shakil, Shazi; Shaikh, Sibhghatulla; Bagga, Paramdeep; Kamal, Mohammad A

    2014-04-01

    Acetylcholinesterase (AChE) is a primary target for Alzheimer's therapy while recently sodium glucose cotransporter 2 (SGLT2) has gained importance as a potential target for Type 2 Diabetes Mellitus (T2DM) therapy. The present study emphasizes the molecular interactions between a new Food and Drug Administration (FDA) approved antidiabetic drug 'Invokana' (chemically known as Canagliflozin) with AChE and SGLT2 to establish a link between the treatment of T2DM and Alzheimer's Disease (AD). Docking study was performed using 'Autodock4.2'. Both hydrophobic and π-π interactions play an important role in the correct positioning of Canagliflozin within SGLT2 and catalytic site (CAS) of AChE to permit docking. Free energy of binding (ΔG) for 'Canagliflozin-SGLT2' interaction and 'Canagliflozin - CAS domain of AChE' interaction were found to be -10.03 kcal/mol and -9.40 kcal/mol, respectively. During 'Canagliflozin-SGLT2' interaction, Canagliflozin was found to interact with the most important amino acid residue Q457 of SGLT2. This residue is known for its interaction with glucose during reabsorption in kidney. However, 'Canagliflozin-CAS domain of AChE' interaction revealed that out of the three amino acids constituting the catalytic triad (S203, H447 and E334), two amino acid residues (S203 and H447) interact with Canagliflozin. Hence, Invokana (Canagliflozin) might act as a potent dual inhibitor of AChE and SGLT2. However, scope still remains in the determination of the three-dimensional structure of SGLT2-Canagliflozin and AChE-Canagliflozin complexes by X-ray crystallography to validate the described data. Since the development of diabetes is associated with AD, the design of new AChE inhibitors based on antidiabetic drug scaffolds would be particularly beneficial. Moreover, the present computational study reveals that Invokana (Canagliflozin) is expected to form the basis of a future dual therapy against diabetes associated neurological disorders.

  9. In vitro and in vivo evaluation of pyridinium oximes: mode of interaction with acetylcholinesterase, effect on tabun- and soman-poisoned mice and their cytotoxicity.

    Calić, Maja; Vrdoljak, Ana Lucić; Radić, Bozica; Jelić, Dubravko; Jun, Daniel; Kuca, Kamil; Kovarik, Zrinka

    2006-02-15

    The increased concern about terrorist use of nerve agents prompted us to search for new more effective oximes against tabun and soman poisoning. We investigated the interactions of five bispyridinium oximes: K027 [1-(4-hydroxyiminomethylpyridinium)-3-(4-carbamoylpyridinium) propane dibromide], K048 [1-(4-hydroxyiminomethylpyridinium)-4-(4-carbamoylpyridinium) butane dibromide], K033 [1,4-bis(2-hydroxyiminomethylpyridinium) butane dibromide], TMB-4 [1,3-bis(4-hydroxyiminomethylpyridinium) propane dibromide] and HI-6 [(1-(2-hydroxyiminomethylpyridinium)-3-(4-carbamoylpyridinium)-2-oxapropane dichloride)] with human erythrocyte acetylcholinesterase (AChE; E.C. 3.1.1.7) and their effects on tabun- and soman-poisoned mice. All the oximes reversibly inhibited AChE, and the enzyme-oxime dissociation constants were between 17 and 180 microM. Tabun-inhibited AChE was completely reactivated by TMB-4, K027 and K048, with the overall reactivation rate constants of 306, 376 and 673 min(-1)M(-1), respectively. The reactivation of tabun-inhibited AChE by K033 reached 50% after 24h, while HI-6 failed to reactivate any AChE at all. Soman-inhibited AChE was resistant to reactivation by 1mM oximes. All studied oximes protected AChE from phosphorylation with both soman and tabun. In vivo experiments showed that the studied oximes were relatively toxic to mice; K033 was the most toxic (LD50=33.4 mg/kg), while K027 was the least toxic (LD50=672.8 mg/kg). The best antidotal efficacy was obtained with K048, K027 and TMB-4 for tabun poisoning, and HI-6 for soman poisoning. Moreover, all tested oximes showed no cytotoxic effect on several cell lines in concentrations up to 0.8mM. The potency of the oximes K048 and K027 to protect mice from five-fold LD50 of tabun and their low toxicity make these compounds leading in the therapy of tabun poisoning. The combination of HI-6 and atropine is the therapy of choice for soman poisoning.

  10. Micropropagation of Ficus religiosa L. via leaf explants and comparative evaluation of acetylcholinesterase inhibitory activity in the micropropagated and conventionally grown plants.

    Siwach, Priyanka; Gill, Anita Rani

    2014-10-01

    A high-frequency, season-independent, in vitro regeneration of Ficusreligiosa was developed, followed by comparative acetylcholinesterase inhibitory (AChEI) activity assay of the in vitro raised and conventionally grown plants. The use of AChEI activity is the most accepted strategy for the treatment of Alzheimer disease. Fully expanded, mature leaves were cut into different segments to initiate the cultures. The middle section of the leaf in vertical orientation with cut portion inserted inside the medium was found most suitable for direct shoot regeneration. Leaf explants responded with nearly consistent frequency (60-66.67 %) throughout the year. To obtain high frequency response with enhanced shoot multiplication rate, 32 plant growth regulator regimes were screened amongst which benzylaminopurine at 5.0 mg/l was found most suitable, yielding 100 % response and maximum number of shoots per explant (7.93); same concentration was also most supportive for repeated multiplication (6.53 shoots). The quality of the shoots and multiplication rate could be significantly enhanced (24.35 shoots) when adenine sulphate, glutamine and phloroglucinol, in an optimised concentration, were additionally supplemented. The clonal nature of the micropropagated plants was confirmed by random amplified polymorphic DNA analysis. A comparative analysis of AChEI activity was carried out amongst the methanolic extracts of stem segments of the mother plant, randomly selected seedlings of different age (4 and 6 months old) of the same mother plant and randomly selected micropropagated plants of different age (3 and 6 months age). The mother plant sample showed effective AChEI activity, with IC50 of 66.46 μg/ml while seedlings, of different age groups, performed poorly (6-month-old seedlings, Se-16M, yielded IC50 of 20,538.46 μg/ml, while two randomly selected 4 months' aged seedlings, Se-24M and Se-34M exhibited IC50 of 19,341.03 and 24,281.70 μg/ml). On the other hand, various

  11. Satellite cells in slow and fast rat muscles differ in respect to acetylcholinesterase regulation mechanisms they convey to their descendant myofibers during regeneration.

    Dolenc, I; Crne-Finderle, N; Erzen, I; Sketelj, J

    1994-02-01

    The hypothesis of satellite cell diversity in slow and fast mammalian muscles was tested by examining acetylcholinesterase (AChE) regulation in muscles regenerating 1) under conditions of muscle disuse (tenotomy, leg immobilization) in which the pattern of neural stimulation is changed, and 2) after cross-transplantation when the regenerating muscle develops under a foreign neural stimulation pattern. Soleus (SOL) and extensor digitorum longus (EDL) muscles of the rat were allowed to regenerate after ischemic-toxic injury either in their own sites or had been cross-transplanted to the site of the other muscle. Molecular forms of AChE in regenerating muscles were analyzed by velocity sedimentation in linear sucrose gradients. Neither tenotomy nor limb immobilization significantly affected the characteristic pattern of AChE molecular forms in regenerating SOL muscles, suggesting that the neural stimulation pattern is probably not decisive for its induction. During an early phase of regeneration, the general pattern of AChE molecular forms in the cross-transplanted regenerating muscle was predominantly determined by the type of its muscle of origin, and much less by the innervating nerve which exerted only a modest modifying effect. However, alkali-resistant myofibrillar ATPase activity on which the separation of muscle fibers into type I and type II is based, was determined predominantly by the motor nerve innervating the regenerating muscle. Mature regenerated EDL muscles (13 weeks after injury) which had been innervated by the SOL nerve became virtually indistinguishable from the SOL muscles in regard to their pattern of AChE molecular forms. However, AChE patterns of mature regenerated SOL muscles that had been innervated by the EDL nerve still displayed some features of the SOL pattern. In regard to AChE regulation, muscle satellite cells from slow or fast rat muscles convey to their descendant myotubes the information shifting their initial development in the

  12. Exploring the Effect of Phyllanthus emblica L. on Cognitive Performance, Brain Antioxidant Markers and Acetylcholinesterase Activity in Rats: Promising Natural Gift for the Mitigation of Alzheimer's Disease

    Uddin, Md. Sahab; Mamun, Abdullah Al; Hossain, Md. Sarwar; Akter, Farjana; Iqbal, Mohammed Ashraful; Asaduzzaman, Md.

    2016-01-01

    Neurodegenerative diseases are incurable and debilitating conditions that result in the progressive degeneration of nerve cells, which affect the cognitive activity. Currently, as a result of multiple studies linking Alzheimer's disease (AD) to oxidative damage, the uses of natural antioxidant to prevent, delay, or enhance the pathological changes underlying the progression of AD has received considerable attention. Therefore, this study was aimed at examining the effect of ethanolic extracts of Phyllanthus emblica (EEPE) ripe (EEPEr) and EEPE unripe (EEPEu) fruits on cognitive functions, brain antioxidant enzymes, and acetylcholinesterase (AChE) activity in rat. The effects of EEPEr and EEPEu fruits (i.e., 100 and 200 mg/kg b.w.) were examined in Swiss albino male rats for 12 days and its effect on cognitive functions, brain antioxidant enzymes, and AChE activity determined. Learning and memory enhancing activity of EEPE fruit was examined by using passive avoidance test and rewarded alternation test. Antioxidant potentiality was evaluated by measuring the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase, reduced glutathione (GSH), glutathione-S-transferase, and the contents of thiobarbituric acid reactive substances (TBARS) in entire brain tissue homogenates. AChE activity was determined using colorimetric method. Administration of the highest dose (i.e., 200 mg/kg b.w.) of EEPEr fruit significantly (p < 0.01) and both lowest and highest doses (i.e., 100 and 200 mg/kg b.w.) of EEPEu fruit markedly (p < 0.05, p < 0.001) increased step-through latency in rats on 6th, 11th, and 12th day with respect to the control group. For aforementioned doses, the percentage of memory retention (MR) was considerably (p < 0.05, p < 0.01) increased in rats on 10th, 11th, and 12th days with respect to the control group. The extract, particularly highest dose (i.e., 200 mg/kg b.w.) of EEPEr

  13. Characteristics of acetylcholinesterase from sea cucumber%海参乙酰胆碱酯酶的酶学特性研究

    杜英; 朱蓓薇; 吴海涛; 柴晓倩

    2011-01-01

    The enzymic characteristics of crude acetylcholinesterase (AChE) from sea cucumber were studied.The crude AChE was extracted from the gut or body wall of sea cucumber with PBS buffer containing 0.1 % Triton X-100, and the activity of AChE was determined by the method of Ellman.The results indicated that AChEs from the gut and body wall of sea cucumber have the similar enzymatic characteristics.The crude AChE displayed maximum activity at pH 8.0 and over 35 ℃, and showed high stability in the range of pH 6.0~8.0 and favorable temperature 25~45 ℃.AChE from sea cucumber hydrolyzed acetylthiocholine iodide (AcSChI) effectively, but showed little effect on butyrylthiocholine iodide (BuSChI).At a concentration higher than 50 mM, AcSChI inhibited the enzyme activity obviously.The activity of AChE was inhibited by Sn2+ ,Zn2+ , Hg2+ ,Ag+ , Cr6+ , Cu2+ and some inhibitors such as Eserine and BW284c51.%对海参乙酰胆碱酯酶(AChE)粗酶的酶学性质进行研究.采用含0.1% Triton X-100 的PBS缓冲液(0.1 M,PH7.4)分别从海参肠和海参体壁中提取 AChE,配合Ellman法测定AChE酶活力.结果表明,海参肠与体壁 AChE 具有相似的酶学性质,其最适反应 pH 值为8.0,pH在6~8时稳定;最适反应温度为35℃左右,在25~45℃内热稳定性较好.海参乙酰胆碱酯酶粗酶液能有效水解碘化硫代乙酰胆碱(AcSChI),但对碘化硫代丁酰胆碱(BuSChI)的作用较弱.当底物AcSChI浓度大于50 mM时产生明显的底物过量抑制效应.金属离子 Sn、Zn、Hg、Ag、Cr、Cu及毒扁豆碱和BW284c51均对海参肠和海参体壁乙酰胆碱酯酶有不同程度的抑制作用.

  14. Effect of Schisandra chinensis polysaccharide on intracerebral acetylcholinesterase and monoamine neurotransmitters in a D-galactose-induced aging brain mouse model

    Mingsan Miao; Jianlian Gao; Guangwei Zhang; Xiao Ma; Ying Zhang

    2009-01-01

    BACKGROUND: The most prominent characteristic of brain aging is decreased learning and memory ability. The functions of learning and memory are closely related to intracerebral acetylcholinesterase (ACHE) and monoamine neurotransmitter activity. Previous studies have shown that Schisandra chinensis potysaccharide has an anti-aging effect. OBJECTIVE: To explore the effects of Schisandra chinensis polysaccharide on AChE activity and monoamine neurotransmitter content, as well as learning and memory ability in a D-galactose-induced aging mouse brain model compared with the positive control drug Kangnaoling. DESIGN, TIME AND SETTING: Completely randomized, controlled experiment based on neurobiochemistry was performed at the Pharmacological Laboratory, Henan University of Traditional Chinese Medicine from September to December 2003.MATERIALS: Schisandra chinensis was purchased from Henan Provincial Medicinal Company. Schisandra chinensis polysaccharide was obtained by water extraction and alcohol precipitation. Kangnaoling pellets were provided by Liaoning Tianlong Pharmaceutical (batch No. 20030804;state drug permit No. H21023095). A total of 50 six-week-old Kunming mice were randomly divided into five groups: blank control, model, Kangnaoling, high and low dosage Schisandra chinensis polysaccharide groups, with 10 mice per group. METHODS: Mice in the blank control group were subcutaneously injected with 0.5 mL/20 g normal saline into the nape of the neck each day, while the remaining mice were subcutaneously injected with 5% D-galactose saline solution (0.5 mL/20 g) in the nape for 40 days to induce a brain aging model. On day 11, mice in the high and low dosage Schisandra chinensis polysaccharide groups were intragastrically infused with 20 mg/mL and 10 mg/mL Schisandra chinensis polysaccharide solution (0.2 mL/10 g), respectively. Mice from the Kangnaoling group were intragastrically infused with 35 mg/mL Kangnaoling suspension (0.2 mL/10 g), and the mice in the

  15. Synthesis and biological evaluation of 1-(4-[{sup 18}f]fluorobenzyl)-4-[(5,6-dimethoxy-1-oxoindan-2-yl)methyl]piperidine for in vivo studies of acetylcholinesterase

    Leea, Sang-Yoon; Choe, Yearn Seong E-mail: yschoe@samsung.co.kr; Sugimoto, Hachiro; Kim, Sang Eun; Hwang, Sae Hwan; Lee, Kyung-Han; Choi, Yong; Lee, Jeewoo; Kim, Byung-Tae

    2000-11-01

    We synthesized and evaluated 1-(4-fluorobenzyl)-4-[(5,6-dimethoxy-1-oxoindan-2-yl)methyl]piperidine (4-FDP), which is an analog of donepezil. The 4-[{sup 18}F]FDP was prepared by reductive alkylation of debenzylated donepezil with 4-[{sup 18}F]fluorobenzaldehyde in high radiochemical yield (decay-corrected, 40-52%) and with high effective specific activity (30-38 GBq/{mu}mol). Tissue distribution studies in mice demonstrated nonspecific distribution of the 4-[{sup 18}F]FDP in brain regions, suggesting that this radioligand may not be a suitable agent for in vivo studies of acetylcholinesterase (AChE), despite its potent in vitro biological activity.

  16. Syntheses and biological evaluation of {sup 18}F-labeled 3-(1-benzyl-piperidin-4-yl)-1-(1-methyl-1H-indol-3-yl)propan-1-ones for in vivo mapping of acetylcholinesterase

    Choe, Y.-S. E-mail: yschoe@samsung.co.kr; Oh, S.-J.; Shim, Insop; Naruto, Shunji; Chi, Dae Yoon; Kim, Sang Eun; Lee, Kyung-Han; Choi, Yong; Kim, B.-T

    2000-04-01

    We synthesized novel {sup 18}F-labeled acetylcholinesterase (AChE) inhibitors, 3-[1-(3- and 4-[{sup 18}F]fluoromethylbenzyl)piperidin-4-yl]-1-(1-methyl-1H-indol-3-yl)propan- 1-ones ([{sup 18}F]1 and [{sup 18}F]2) and 3-[1-(4-[{sup 18}F]fluorobenzyl)piperidin-4-yl]-1-(1-methyl-1H-indol-3-yl)propan- 1-one ([{sup 18}F]3) in high yields (decay-corrected, 25%-40%) and with high effective specific activities (>37 GBq/{mu}mol). Tissue distribution studies of the [{sup 18}F]1 and the [{sup 18}F]3 in mice showed the nonspecific bindings in brain regions, with metabolic defluorination of the [{sup 18}F]1. The result suggests that these radioligands may not be suitable agents for in vivo mapping of AChE, despite their potent in vitro anti-AChE activities.

  17. 抗药性与敏感性德国小蠊乙酰胆碱酶的活性比较%A comparative study on the activity of acetylcholinesterase in the pesticides resistant strains of Blattella germanica

    王式春; 林琳; 刘渠; 张起文; 沈培林; 韦薇; 王德全

    2011-01-01

    目的 研究德国小蠊抗药性与乙酰胆碱酯酶活性的关系.方法 采用化学比色方法对敏感品系和抗性品系的德国小蠊分别测试乙酰胆碱酯酶,对比两者的测定值,分析抗性品系和敏感品系德国小蠊乙酰胆碱酯酶的差异.结果 敏感品系和抗性品系德国小蠊的乙酰胆碱酯酶活性分别是2.863和5.609,抗性品系德国小蠊酶活性显著高于敏感品系,两者酶活性比值为1.96.结论 乙酰胆碱酯酶活性与德国小蠊抗药性有关.%Objective To study the activity of acetylcholinesterase (AChE) in insecticide resistant German cockroaches.Methods Different strains and gender of German cockroaches were used in this study. Colorimetric method was used to determine the activity of acetylcholinesternse. Results Blattella germanica were studied for their acetylcholinesterase activity.AChE activity in the insecticide resistant and insecticide sensitive strains was 2.863 and 5.609, respectively. AChE activity of the field strain was significantly higher than the susceptible strain. And the ratio of AChE activity between the resistant and the sensitive strain was 1.96. Conclusion The activity of AChE from the field strains was correlated with the pesticides resistance.

  18. Chemical composition and acetylcholinesterase inhibitory activity of essential oils of Myrceugenia myrcioides(Cambess.) O. Berg and Eugenia riedelianaO. Berg, Myrtaceae Composição química e atividade inibidora de acetilcolinesterase de óleos voláteis de Myrceugenia myrcioides(Cambess.) O. Berg and Eugenia riedeliana O. Berg, Myrtaceae

    2010-01-01

    The chemical composition of volatile oils from two Myrtaceae species, Myrceugenia myrcioidesand Eugenia riedeliana, both native from the Brazilian Atlantic Rain Forest, was analyzed by GC-MS. Acetylcholinesterase inhibitory activity was colorimetrically evaluated for these oils. For M. myrcioides, monoterpene hydrocarbons represented the major class in the volatile oil, with α-pinene as the most abundant component and a weak inhibitory activity was observed, whilst for E. riedeliana sesq...

  19. Correlation of cognitive function with acetylcholinesterase activity and P300 event-related potential of patients with type 2 diabetes mellitus

    Suguo Yu; Yingxue Wang; Jihua Sun; Xuewen Han

    2006-01-01

    BACKGROUND: At present, central cholinergic neuron system is regarded the most major structural basis of cognitive function. Changes in structure of cholinergic neuron system of brain and receptor expression after brain injury can cause cognitive impairment.OBJECTIVE: To comparatively observe the intelligence quotient (IQ), latent period and wave amplitude of P300 event-related potential and the difference of activity of acetylcholinesterase (AChE) in blood and cerebrospinal fluid between patients with type 2 diabetes mellitus and with non-diabetes mellitus, and analyze the correlation of IQ of cognitive impairment patients with diabetes mellitus with AChE activity, latent period and wave amplitude of P300 event-related potential in cerebrospinal fluid.DESIGN: Correlation analysis of contrast observation.SETTING: Department of Endocrinology, Affiliated Hospital of Binzhou Medical College.PARTICIPANTS: Totally 32 patients with type 2 diabetes mellitus who received the treatment in the Department of Endocrinology, Affiliated Hospital of Binzhou Medical College between April 2004 and April 2005 were recruited, serving as diabetes mellitus group. They, including 19 male and 13 female, aged 49 to 73 years, with disease course of 4 to 11 years, all met the diagnostic criteria of diabetes mellitus revised by World Health Organization in 1999. Another 30 patients with non-diabetes mellitus who homeochronously underwent lumbar anesthesia in the Department of Surgery and Department of Gynecology were recruited, serving as non-diabetes mellitus group. The 30 patients included 18 male and 12 female,and their age ranged from 46 to 71 years. Informed consents of detected items were obtained from the involved patients.METHODS: ① Evaluation,on IQ: The IQ of involved subjects was evaluated with Chinese Version of the Wechsler Adult Intelligence Scale revised by Gong Yao-xian (WAIS-RC). WAIS-RC included 6 verbal subscales and 5 performance subscales. The test scores of the 11

  20. Biochemical effects of glyphosate based herbicide, Excel Mera 71 on enzyme activities of acetylcholinesterase (AChE), lipid peroxidation (LPO), catalase (CAT), glutathione-S-transferase (GST) and protein content on teleostean fishes.

    Samanta, Palas; Pal, Sandipan; Mukherjee, Aloke Kumar; Ghosh, Apurba Ratan

    2014-09-01

    Effects of glyphosate based herbicide, Excel Mera 71 at a dose of 17.20mg/l on enzyme activities of acetylcholinesterase (AChE), lipid peroxidation (LPO), catalase (CAT), glutathione-S-transferase (GST) and protein content were measured in different tissues of two Indian air-breathing teleosts, Anabas testudineus (Bloch) and Heteropneustes fossilis (Bloch) during an exposure period of 30 days under laboratory condition. AChE activity was significantly increased in all the investigated tissues of both fish species and maximum elevation was observed in brain of H. fossilis, while spinal cord of A. testudineus showed minimum increment. Fishes showed significant increase LPO levels in all the tissues; highest was observed in gill of A. testudineus but lowest LPO level was observed in muscle of H. fossilis. CAT was also enhanced in both the fishes, while GST activity in liver diminished substantially and minimum was observed in liver of A. testudineus. Total protein content showed decreased value in all the tissues, maximum reduction was observed in liver and minimum in brain of A. testudineus and H. fossilis respectively. The results indicated that Excel Mera 71 caused serious alterations in the enzyme activities resulting into severe deterioration of fish health; so, AChE, LPO, CAT and GST can be used as suitable indicators of herbicidal toxicity.

  1. Synthesis and screening for acetylcholinesterase inhibitor activity of some novel 2-butyl-1,3-diaza-spiro[4,4]non-1-en-4-ones: derivatives of irbesartan key intermediate.

    Kavitha, C V; Gaonkar, S L; Narendra Sharath Chandra, J N; Sadashiva, C T; Rangappa, K S

    2007-12-01

    The association of bioactive nucleus with other pharmacological agents is hoped to improve the efficacy of the treatment by combining the effects of different pharmacological mechanisms of action. Keeping this in view, a series of 2-butyl-1,3-diaza-spiro[4,4]non-1-en-4-one derivatives have been synthesized by interaction of 2-butyl-1,3-diaza-spiro[4,4]non-1-en-4-one with different bioactive aralkyl halides in presence of powdered potassium carbonate by two different methods viz., conventional and microwave irradiation. The yields under conventional and microwave irradiation methods were in the range of 60-65% and 80-90%, respectively. The structure elucidation of the new compounds has been carried out with the help of elemental analysis and spectral data. All the synthesized compounds have been screened for their efficacy as acetylcholinesterase (AChE) inhibitor. AChE inhibitory activity study was carried out by using Ellman colorimetric assay with neostigmine as a reference standard against targets from different species, such as pure electric eel AChE, human serum AChE, and rat brain AChE. Among the compounds synthesized, compounds 5a, 5b, 5j showed good inhibition against AChE.

  2. Synthesis and biological activity of 3,6-diaryl-7H-thiazolo[3,2-b][1,2,4]triazin-7-one derivatives as novel acetylcholinesterase inhibitors

    WAN; David; ChiCheong

    2010-01-01

    Acetylcholinesterase inhibitors played significant roles in treatment of Alzheimer’s disease.Based on the research foundation of our previous work and molecular modeling,twelve 3,6-diaryl-7H-thiazolo[3,2-b][1,2,4]triazin-7-one derivatives were synthesized and characterized by mass spectra,infrared spectra,NMR and elemental analyses.The study of AChE inhibitory activity was carried out using the Ellman colorimetric assay with huperzine-A as the positive control.All target compounds exhibited more than 40% inhibition at 10 μM.Some target compounds showed good inhibition against AChE.The preliminary structure-activity relationships were the halogen atoms at the phenyl ring at the C6 position,the hydroxy groups and the long side chains at the phenyl ring at the C3 position of the parent nucleus played significant roles in the AChE inhibitory activity of the target compounds.

  3. Design, synthesis characterization and in vitro biological activity of a series of 3-aryl-6-(bromoarylmethyl)-7H-thiazolo[3,2-b]-1, 2, 4-triazin-7-one derivatives as the novel acetylcholinesterase inhibitors

    He Nan Xu; Zhe Jin; Si Jie Liu; Hong Min Liu; Shuo Li; Huang Quan Lin; David Chicheong Wan; Chun Hu

    2012-01-01

    Bromination is used as a strategy to improve biological activity in medicinal chemistry.In order to study on the structure-activity relationships of the novel acetylcholinesterase inhibitors with 7H-thiazolo[3,2-b]-1,2,4-triazin-7-one scaffold,based on our previous work and molecular modeling,a series of novel 3-aryl-6-(bromoarylmethyl)-7H-thiazolo[3,2-b]-1,2,4-triazin-7-one derivatives were designed by molecular docking,synthesized and characterized by mass spectra,infrared spectra,proton NMR and elemental analyses.The study of AChE inhibitory activity was carried out using the Ellman colorimetric assay with huperzine-A as the positive control.Most of all target compounds exhibited more than 45% inhibition at 10 μmol/L.The preliminary structure-activity relationship was the bromine atoms and the hydroxyl group at the phenyl ring at the C6 position of the parent nucleus played significant roles in the AChE inhibitory activity of the target compounds.

  4. Laboratory and Simulated Field Bioassays to Evaluate Larvicidal Activity of Pinus densiflora Hydrodistillate, Its Constituents and Structurally Related Compounds against Aedes albopictus, Aedes aegypti and Culex pipiens pallens in Relation to Their Inhibitory Effects on Acetylcholinesterase Activity

    Young-Joon Ahn

    2013-05-01

    Full Text Available The toxicity of Pinus densiflora (red pine hydrodistillate, its 19 constituents and 28 structurally related compounds against early third-instar larvae of Aedes albopictus (Ae. albopictus, Aedes aegypti (Ae. aegypti and Culex pipiens palles (Cx. p. pallens was examined using direct-contact bioassays. The efficacy of active compounds was further evaluated in semi-field bioassays using field-collected larval Cx. p. pallens. Results were compared with those of two synthetic larvicides, temephos and fenthion. In laboratory bioassays, Pinus densiflora hydrodistillate was found to have 24 h LC50 values of 20.33, 21.01 and 22.36 mg/L against larval Ae. albopictus, Ae. aegypti and Cx. p. pallens respectively. Among the identified compounds, thymol, δ-3-carene and (+-limonene exhibited the highest toxicity against all three mosquito species. These active compounds were found to be nearly equally effective in field trials as well. In vitro bioassays were conducted to examine the acetylcholinesterase (AChE inhibitory activity of 10 selected compounds. Results showed that there is a noticeable correlation between larvicidal activity and AChE inhibitory activity. In light of global efforts to find alternatives for currently used insecticides against disease vector mosquitoes, Pinus densiflora hydrodistillate and its constituents merit further research as potential mosquito larvicides.

  5. Laboratory and Simulated Field Bioassays to Evaluate Larvicidal Activity of Pinus densiflora Hydrodistillate, Its Constituents and Structurally Related Compounds against Aedes albopictus, Aedes aegypti and Culex pipiens pallens in Relation to Their Inhibitory Effects on Acetylcholinesterase Activity.

    Lee, Dong Chan; Ahn, Young-Joon

    2013-05-30

    The toxicity of Pinus densiflora (red pine) hydrodistillate, its 19 constituents and 28 structurally related compounds against early third-instar larvae of Aedes albopictus (Ae. albopictus), Aedes aegypti (Ae. aegypti) and Culex pipiens palles (Cx. p. pallens) was examined using direct-contact bioassays. The efficacy of active compounds was further evaluated in semi-field bioassays using field-collected larval Cx. p. pallens. Results were compared with those of two synthetic larvicides, temephos and fenthion. In laboratory bioassays, Pinus densiflora hydrodistillate was found to have 24 h LC50 values of 20.33, 21.01 and 22.36 mg/L against larval Ae. albopictus, Ae. aegypti and Cx. p. pallens respectively. Among the identified compounds, thymol, δ-3-carene and (+)-limonene exhibited the highest toxicity against all three mosquito species. These active compounds were found to be nearly equally effective in field trials as well. In vitro bioassays were conducted to examine the acetylcholinesterase (AChE) inhibitory activity of 10 selected compounds. Results showed that there is a noticeable correlation between larvicidal activity and AChE inhibitory activity. In light of global efforts to find alternatives for currently used insecticides against disease vector mosquitoes, Pinus densiflora hydrodistillate and its constituents merit further research as potential mosquito larvicides.

  6. Pyridine sulfonamide as a small key organic molecule for the potential treatment of type-II diabetes mellitus and Alzheimer's disease: In vitro studies against yeast α-glucosidase, acetylcholinesterase and butyrylcholinesterase.

    Riaz, Sadaf; Khan, Islam Ullah; Bajda, Marek; Ashraf, Muhammad; Qurat-Ul-Ain; Shaukat, Ayesha; Rehman, Tanzeel Ur; Mutahir, Sadaf; Hussain, Sajjad; Mustafa, Ghulam; Yar, Muhammad

    2015-12-01

    This paper presents the efficient high yield synthesis of novel pyridine 2,4,6-tricarbohydrazide derivatives (4a-4i) along with their α-glucosidase, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition activities. The enzymes inhibition results showed the potential of synthesized compounds in controlling both type-II diabetes mellitus and Alzheimer's disease. In vitro biological investigations revealed that most of compounds were more active against yeast α-glucosidase than the reference compound acarbose (IC50 38.25±0.12μM). Among the tested series the compound 4c bearing 4-flouro benzyl group was noted to be the most active (IC50 25.6±0.2μM) against α-glucosidase, and it displayed weak inhibition activities against AChE and BChE. Compound 4a exhibited the most desired results against all three enzymes, as it was significantly active against all the three enzymes; α-glucosidase (IC50 32.2±0.3μM), AChE (IC50 50.2±0.8μM) and BChE (IC50 43.8±0.8μM). Due to the most favorable activity of 4a against the tested enzymes, for molecular modeling studies this compound was selected to investigate its pattern of interaction with α-glucosidase and AChE targets.

  7. Effect of sublethal doses of imidacloprid on Acetylcholinesterase activity inApis mellifera%吡虫啉对意大利蜜蜂乙酰胆碱酯酶的亚致死效应

    靳三省; 孟丽峰; 刁青云

    2015-01-01

    [目的]确定吡虫啉对意大利蜜蜂Apis mellifera的致死中浓度,探究吡虫啉对意大利蜜蜂乙酰胆碱酯酶的亚致死效应.[方法]本文采用药膜法、点滴法和饲喂法测定吡虫啉对意大利蜜蜂的毒力曲线,及蜜蜂接触吡虫啉后头部乙酰胆碱酯酶活性的变化.应用 RT-qPCR技术研究饲喂 LC5浓度吡虫啉后,蜜蜂乙酰胆碱酯酶基因Ace1和Ace2的mRNA相对表达量.[结果] 饲喂法、点滴法和药膜法3种方法测定的吡虫啉对意大利蜜蜂的致死中浓度分别是7.15 mg/L、0.078 ng/蜂和51 ng/cm2.3种作用方式下,吡虫啉均抑制了乙酰胆碱酯酶活性;随着浓度增加,AChE 酶活性处于下降状态,但降低较少.LC5浓度的吡虫啉对蜜蜂AChE活性具有明显影响,24 h内AChE活性呈现增强-抑制-增强的趋势.饲喂蜜蜂LC5亚致死浓度的吡虫啉后,Ace1和Ace2被诱导表达,但在1、2和16 h与对照无明显差异.[结论]亚致死浓度的吡虫啉对蜜蜂乙酰胆碱酯活性具有抑制作用,并且存在明显的剂量效应和时间效应,对Ace1和Ace2具有诱导效应,酶活性水平和mRNA相对表达水平不一致.%[Objectives]To determine the median lethal concentration of imidacloprid and explore the sublethal effect of imidacloprid on acetylcholinesterase (AChE) inApis mellifera. [Methods]The toxicity of imidacloprid was determined by feeding trials, topical application and the residual film method. AChE activity and the relative expression of acetylcholinesterase mRNA genes (Ace1 andAce2) in the head ofA. Mellifera were measured after exposure to different concentrations of imidacloprid after different periods of time.[Results] LC50values determined by the three methods were 7.15 mg/L、0.078 ng/bee and 51 ng/cm2, respectively. Imidacloprid inhibited AChE activity within 24 h. The enzymatic activity of AChE was volatile with increasing pesticide concentration, fluctuating with the dose and period of imidacloprid exposure. m

  8. 重组人乙酰胆碱酯酶的表达及其抑制剂的筛选%Expression of recombinant human acetylcholinesterase and its application in screening its inhibitors

    王向军; 吴怀秀; 叶珊珊; 潘兰英; 钱永常

    2014-01-01

    本研究旨在表达重组人乙酰胆碱酯酶(recombinant human acetylcholinesterase,rhAChE)并应用于乙酰胆碱酯酶抑制剂筛选研究.利用质粒pCMV-AChE瞬时转染HEK293细胞,分泌表达rhAChE.考察rhAChE的酶活性:以碘化硫代乙酰胆碱(ATCh)为底物进行酶底物动力学研究获得rhAChE的米氏常数Km,以多奈哌齐(donepezil)为抑制剂进行酶抑制作用动力学研究获得Ki、Ki’等参数.利用rhAChE测定新化合物的IC50值,评价新化合物的抑制活性,同时将研究结果与文献报道的提取大鼠AChE的抑制活性进行比较.结果测得rhAChE的Km为151.9 μtmol·L-1,多奈哌齐对rhAChE的抑制作用为竞争性和非竞争性结合的混合类型(Ki=16.03 nmol·L-1,Ki'=18.36 nmol·L-1),rhAChE可应用于抑制剂筛选研究.

  9. Screening of Some Medicinal Plants for Acetylcholinesterase Inhibition and Antioxidant Activity%药用植物中乙酰胆碱酯酶抑制活性和抗氧化活性的筛选

    杨赟; 刘敏; 李建; 张玉强; 陆亮

    2013-01-01

    目的:对24种药用植物醇提物的乙酰胆碱酯酶抑制活性和抗氧化活性进行筛选研究.方法:70%乙醇回流提取植物粗提物;目标粗提物采用氯仿、乙酸乙酯、正丁醇依次萃取,得到氯仿、乙酸乙酯、正丁醇和水部位;乙酰胆碱酯酶抑制活性测定采用改良的Ellman法和薄层色谱(TLC)生物自显影法相结合的方法;抗氧化活性采用清除DPPH自由基能力进行评价.结果:结合改良Ellman法和TLC生物自显影法对24种植物的醇提物的抗乙酰胆碱酯酶抑制活性进行评价,结果表明红毛七、金不换、飞龙掌血、白花映山红和八角枫5种植物粗提物具有显著的抑制活性,在终浓度为1g·L-1时,其抑制率分别为(88.72±1.47)%,(82.25±1.32)%,(77.71±1.61)%,(77.00±1.38)%,(75.22±1.28)%,其清除DPPH自由基IC50分别为153.75,74.95,50.00,10.87,24.40mg·L-1.在这5种植物粗提物不同萃取部位中,红毛七和金不换氯仿部位对乙酰胆碱酯酶抑制活性最强,其IC50为33.97,38.79mg·L-1,其清除DPPH自由基的IC50为302.95,79.45 mg·L-1.结论:金不换和红毛七粗提物氯仿部位具有较强的乙酰胆碱酯酶抑制活性和抗氧化活性,可进行进一步的追踪分离研究.%Objective: The ethanol extracts of 24 medicinal plants were screened for their anti-acetylcholinesterase ( AChE) activity and antioxidant activity. Method: The medicinal plants were extracted by ethanol (70%) under reflux. The objective extracts would be extracted by different solvents-dichloromethane, ethyl acetate, rc-butanol, and water respectively, in order to obtain their dichloromethane, ethyl acetate, n-butanol, and aqueous-soluble fractions. The AChE inhibitory activity was tested by TLC bioautographic method combined with modified Ellman's colorimetric method; Antioxidant activity was evaluated by 2, 2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. Result; On the basis of the evaluation of 24 medicinal

  10. Resistance detection of Musca domestica in various habitats with the method of acetylcholinesterase%乙酰胆碱酯酶用于不同生境家蝇抗药性研究

    陶卉英; 马红梅; 柳小青; 陈海婴; 熊志伟; 郭学俭; 李卫民

    2009-01-01

    Objective To detect the resistance of Musca domestics in various habitats in early phase with the method of acetylcholinesterase. Methods The traditional assay method and acetylcholinesterase were used to detect the resistance of M. domestica in various habitats to dichlorvos (DDVP) and propoxur. Results The bioassay results showed that 4 strains of M. domestics in the residential areas, restaurants, refuse transfer stations and agricultural fair had different resistance to DDVP, and the resistance ratio were 34.07, 22.57,20.05 and 17.43, respectively. The resistance ratio to propoxur was 2.68, 3.48, 2.15 and 2.74, respectively. The DDVP-resistanee individual rates of 4 strains in the residential areas, restaurants, refuse transfer stations and agricultural fair were 100%, 82%, 55% and 29%, while propoxur-resistant individual rates of them were 28%, 42%, 12% and 27%, respectively. Except for the strain in refuse transfer stations, the others had resistance to DDVP and propoxur. Conclusion The detection results of acetylcholinesterase were basically consistent with that of bioaasays, and it could be used to the early detection of resistance. The 4 resistant strains had middle or high resistance to DDVP and low resistance to propoxur. So, DDVP should be inhibited, and the mixed and rotational use measure could be taken to avoid and delay the development of resistance.%目的 应用一种家蝇抗药性早期检测方法即乙酰胆碱酯酶(AChE)法,了解南昌市不同生境家蝇对常用的有机磷和氨基甲酸酯类杀虫剂的抗性现状及其发展趋势.方法 采用微量点滴法进行生物测定,同时采用AChE检测不同生境家蝇对敌敌畏和残杀威的抗性水平.结果 生物测定结果表明,居民区、餐饮店、垃圾中转站和农贸市场4个家蝇品系对敌敌晨和残杀威产生了不同程度的抗性,对敌敌畏的抗性指数依次为34.07、22.57、20.05、17.43倍,其中农贸市场品系为中抗水平,其余3个品

  11. Chemical composition and acetylcholinesterase inhibitory activity of essential oils of Myrceugenia myrcioides(Cambess. O. Berg and Eugenia riedelianaO. Berg, Myrtaceae Composição química e atividade inibidora de acetilcolinesterase de óleos voláteis de Myrceugenia myrcioides(Cambess. O. Berg and Eugenia riedeliana O. Berg, Myrtaceae

    Amanda de Souza

    2010-05-01

    Full Text Available The chemical composition of volatile oils from two Myrtaceae species, Myrceugenia myrcioidesand Eugenia riedeliana, both native from the Brazilian Atlantic Rain Forest, was analyzed by GC-MS. Acetylcholinesterase inhibitory activity was colorimetrically evaluated for these oils. For M. myrcioides, monoterpene hydrocarbons represented the major class in the volatile oil, with α-pinene as the most abundant component and a weak inhibitory activity was observed, whilst for E. riedeliana sesquiterpenes were found in higher amounts, being valerianol the major compound, and this oil presented a strong acetylcholinesterase inhibition.A composição química dos óleos voláteis de duas espécies de Myrtaceae, Myrceugenia myrcioidese Eugenia riedeliana, ambas nativas da Mata Atlântica, foi analisada por CG-EM. A atividade inibidora de acetilcolinesterase foi determinada colorimetricamente para estes óleos. Em M. myrcioides, hidrocarbonetos monoterpênicos representaram a classe majoritária de compostos presentes no óleo volátil, sendo α-pineno o componente mais abundante e a atividade inibidora de acetilcolinesterase foi baixa, enquanto para E. riedelianaos sesquiterpenos foram observados em maiores concentrações, sendo o valerianol o componente majoritário, e este óleo apresentou uma forte atividade inibidora da enzima.

  12. Temperature rise and microplastics interact with the toxicity of the antibiotic cefalexin to juveniles of the common goby (Pomatoschistus microps): Post-exposure predatory behaviour, acetylcholinesterase activity and lipid peroxidation.

    Fonte, Elsa; Ferreira, Pedro; Guilhermino, Lúcia

    2016-11-01

    The goal of this study was to investigate the toxicity of cefalexin to Pomatoschistus microps juveniles in relation to the presence of microplastics in the water and temperature rise. After acclimatization, groups of wild juveniles were exposed for 96h to artificial salt water (control), microplastics alone (0.184mg/l), cefalexin alone (1.3-10mg/l) and in mixture with microplastics (cefalexin: 1.3-10mg/l; microplastics: 0.184mg/l) at 20 and 25°C. Effect criteria were mortality, post-exposure predatory performance (PEPP), acetylcholinesterase activity (AChE) and lipid peroxidation levels (LPO). At 20°C, concentrations of cefalexin alone≥5mg/l significantly reduced PEPP (up to 56%; 96h-EC50=8.4mg/l), indicating toxicity of the antibiotic to juveniles after short-term exposure to water concentrations in the low ppm range. At 20°C, fish exposed to microplastics alone did not have significant differences in any of the parameters tested relative to the control group but tended to have an inhibition of the PEPP (23%) and AChE (21%); at 25°C, microplastics alone caused mortality (33%) and PEPP inhibition (28%). Thus, microplastics are toxic to P. microps juveniles. At 20°C, under simultaneous exposure to cefalexin and microplastics, the PEPP was significantly reduced (at cefalexin concentrations≥1.25mg/l). Moreover, at 25°C, the toxicity curves of cefalexin (PEPP based), alone and in mixture with microplastics, were significantly different (pmicroplastics in the water influenced the toxicity of cefalexin. The rise of water temperature (from 20°C to 25°C), increased the microplastics-induced mortality (from 8 to 33%), and the inhibitory effects of cefalexin on the PEPP (up to 70%). Significant differences (pmicroplastics and of cefalexin, alone and in mixture with microplastics, to P. microps juveniles. These findings raise concern on the long-term exposure of wild populations to complex mixtures of pollutants, likely decreasing their fitness, and highlight the

  13. Efeito do extrato da casca de Syzygium cumini sobre a atividade da acetilcolinesterase em ratos normais e diabéticos Syzygium cumini bark extract effect on acetylcholinesterase activity in normal and diabetic rats

    Cinthia Melazzo Mazzanti

    2004-06-01

    Full Text Available Este estudo verificou a eficiência do extrato etanólico da casca de Syzygium cumini sobre o sistema colinérgico de ratos normais e diabéticos induzidos com aloxano. Os animais foram divididos em grupo controle (C, tratado com Syzygium cumini (TS, diabético (D e diabético tratado com Syzygium cumini (DS. A atividade da acetilcolinesterase (AChE foi analisada nas seguintes estruturas cerebrais: cerebelo, córtex, estriado e hipocampo. O extrato etanólico da casca de Syzygium cumini na dose de 1g.kg-1 foi administrado diariamente por um período de trinta dias. Foi verificado após este período que o extrato inibiu a atividade da AChE no cerebelo e córtex cerebral dos ratos do grupo DS (PThe present study verified the efficiency of the bark ethanol extract of Syzygium cumini on the cholinergic system of normal and alloxan induced diabetic rats. Thirty-nine female rats were divided in control (C, treated with Syzygium cumini (TS, diabetic (D and diabetic treated with Syzygium cumini (DS. The activity of acetylcholinesterase (AChE was analyzed in the following cerebral structures: cerebellum, cortex, striatum and hippocampus. The extract of the bark of Syzygium cumini in the dose of 1g.kg-1 was administered orally daily for a period of thirty days. After this period the extract inhibited the activity of the AChE in the cerebellum and cerebral cortex of the rats in the DS group (P<0.05 as, compared to TS. In the striatum there was a significant increase in the activity of the AChE in rats of the TS group (P<0.01 when compared to the C group, and in the hippocampus there was no significant variation. These results indicate that the bark extract of "Jambolão"has an inhibitory effect on AChE in the cerebellum and cerebral cortex and an stimulatory effect on striatum, indicating a possible alteration in the functionality of the cholinergic system in such cerebral structures.

  14. Acetylcholinesterase enzyme activity in carp brain and muscle after acute exposure to diafuran Atividade da enzima acetilcolinesterase em cérebro e músculo de carpas após exposição aguda ao diafuran

    Jaqueline Ineu Golombieski

    2008-01-01

    Full Text Available Sublethal adverse effects may result from exposure of aquatic organisms to insecticides at environmentally relevant concentrations. Fingerlings of the common carp (Cyprinus carpio, Linnaeus, 1758, grass carp (Ctenopharyngodon idella, Valenciennes, 1844, and bighead carp (Aristichthys nobilis, Richardson, 1845 were exposed to diafuran, an insecticide widely used during rice cultivation in Southern Brazil. The aim of this study was to verify the relationship between the lethal concentration (LC50 of diafuran and the acetylcholinesterase (AChE activity in brain and muscle tissues of these species as a possible early biomarker of exposure to this insecticide. LC50 was determined for fish exposed to diafuran concentrations during 96 h (short term: common carp: control, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mg L-1; grass carp: control, 1.0, 2.0, 3.0 and 3.5 mg L-1 and, bighead carp: control, 0.5, 1.0, 1.5, 2.0, 3.0 and 4.0 mg L-1, as well as the determination of AChE at concentrations near LC50 for these species. LC50 values (nominal concentrations were 1.81 mg L-1 for the common carp, 2.71 mg L-1 for the grass carp and, 2.37 mg L-1 for the bighead carp. All carps exposed to diafuran were lethargic (lower concentrations or immobile. Diafuran inhibited the acetylcholinesterase activity in brain (~38% and muscle (~50% of all species. Muscle of bighead carp under control treatment showed higher specific AChE activity than brain (14.44 against 5.94 µmol min-1 g protein-1, respectively. Concentrations of diafuran used for rice cropping may affect Cyprinus carpio, Ctenopharyngodon idella and Aristichthys nobilis behaviors and the AChE activities in brain and muscle of these species may be an early biomarker of toxicity of this insecticide.Exposição a inseticidas em concentrações elevadas no ambiente podem ocasionar efeitos adversos subletais em organismos aquáticos. Alevinos de carpa húngara (Cyprinus carpio, Linnaeus, 1758, carpa capim (Ctenopharyngodon

  15. Musical hallucinations treated with acetylcholinesterase inhibitors

    Blom, Jan Dirk; Coebergh, Jan Adriaan F; Lauw, René; Sommer, Iris E C

    2015-01-01

    Musical hallucinations are relatively rare auditory percepts which, due to their intrusive nature and the accompanying fear of impending mental decline, tend to cause significant distress and impairment. Although their etiology and pathophysiology appear to be heterogeneous and no evidence-based tre

  16. Bridged Bicyclic Oximes as Acetylcholinesterase Reactivators

    1988-04-03

    i3co "i 0 OC, NO 4 Nol NH1 NO" 49 Finally we have developed a synthesis for diaryl 1,4- diketones (51). This synthesis involves the coupling of...Discussion of Kinetic Data 24 8. Conclussions 24 9. Synthesis and Characterization of Compounds 25 10. References 44 11. Publications From the Two Years 49...methiodide. f. Synthesis of a-hydroxyketones. a-methoxy ketones has been achieved using hvper valent iodine oxidation of trimethyl silyl enol ethers of

  17. Acetylcholinesterase Inhibitors on the Spinal Cord.

    1991-11-22

    in vitro. J. Pharmacol. Exp. Ther. 248, 1048-1053. 19. Cheney, P.D., Kasser , R.J., and Holsapple, J. (1987) Effects of DFP on unit activity in rat... Kasser , R.J., and Cheney, P.D. (1987) DFP action on rat superior colliculus: localization and role of cholinergic receptors. Neurotoxicology 8, 607

  18. Acetylcholinesterase inhibition ameliorates deficits in motivational drive

    Martinowich Keri

    2012-03-01

    Full Text Available Abstract Background Apathy is frequently observed in numerous neurological disorders, including Alzheimer's and Parkinson's, as well as neuropsychiatric disorders including schizophrenia. Apathy is defined as a lack of motivation characterized by diminished goal-oriented behavior and self-initiated activity. This study evaluated a chronic restraint stress (CRS protocol in modeling apathetic behavior, and determined whether administration of an anticholinesterase had utility in attenuating CRS-induced phenotypes. Methods We assessed behavior as well as regional neuronal activity patterns using FosB immunohistochemistry after exposure to CRS for 6 h/d for a minimum of 21 d. Based on our FosB findings and recent clinical trials, we administered an anticholinesterase to evaluate attenuation of CRS-induced phenotypes. Results CRS resulted in behaviors that reflect motivational loss and diminished emotional responsiveness. CRS-exposed mice showed differences in FosB accumulation, including changes in the cholinergic basal forebrain system. Facilitating cholinergic signaling ameliorated CRS-induced deficits in initiation and motivational drive and rescued immediate early gene activation in the medial septum and nucleus accumbens. Conclusions Some CRS protocols may be useful for studying deficits in motivation and apathetic behavior. Amelioration of CRS-induced behaviors with an anticholinesterase supports a role for the cholinergic system in remediation of deficits in motivational drive.

  19. Reactivation of Aged Organophosphorus Inhibited Acetylcholinesterase

    1986-08-31

    oximes followed, for the most part, reactions for which significant precedent exists. 8 Th yntheses toDate : (1) The Initial Coriensation Reaction...crude mixture into pyridine and, although yields from the sulfur method were slightly higher than those by nitric acid oxidation, work- up was far more...worked up as indicated above and, without further purification, 25, in acetic anhydride (10 mL) was added dropwise to an additional portCon (30 mL

  20. Potent acetylcholinesterase inhibitory compounds from Myristica fragrans.

    Cuong, To Dao; Hung, Tran Manh; Han, Hyoung Yun; Roh, Hang Sik; Seok, Ji-Hyeon; Lee, Jong Kwon; Jeong, Ja Young; Choi, Jae Sue; Kim, Jeong Ah; Min, Byung Sun

    2014-04-01

    The anti-cholinesterase activity was evaluated of the ethyl acetate fraction of the methanol extract of Myristica fragrans Houtt (Myristicaceae) seeds and of compounds isolated from it by various chromatographic techniques. The chemical structures of the compounds were determined from spectroscopic analyses (NMR data). Thirteen compounds (1-13) were isolated and identified. Compound 8 { [(7S)-8'-(4'-hydroxy-3'-methoxyphenyl)-7-hydroxypropyl]benzene-2,4-diol) showed the most effective activity with an IC50 value of 35.1 microM, followed by compounds 2 [(8R,8'S)-7'-(3',4'-methylenedioxyphenyl)-8,8'-dimethyl-7-(3,4-dihydroxyphenyl)-butane] and 11 (malabaricone C) with IC50 values of 42.1 and 44.0 pM, respectively. This is the first report of significant anticholinesterase properties of M. fragrans seeds. The findings demonstrate that M. fragrans could be used beneficially in the treatment of Alzheimer's disease.