WorldWideScience

Sample records for acetylcholinesterase

  1. Photodestruction of acetylcholinesterase

    Ultraviolet irradiation of 11S acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7) produces a loss of tryptophan fluorescence which is best described as the sum of two separable first-order processes, one much more rapid than the other. In addition, the enzyme undergoes an all-or-none inactivation that is monotonically first order. Simultaneous with activity loss, photoscission takes place and results in a molecular weight drop. The extreme sensitivity of acetylcholinesterase to photodestruction upon photon absorption and the several events that follow it not only suggest that these findings might be a basis for a useful molecular probe of the structure of this enzyme, but also indicate that additional care should be taken when conducting spectroscopic studies in the uv region

  2. Molecular Dynamics of Acetylcholinesterase

    Shen, T Y.; Tai, Kaihsu; Henchman, Richard H.; Mccammon, Andy

    2002-06-01

    Molecular dynamics simulations are leading to a deeper understanding of the activity of the enzyme acetylcholinesterase. Simulations have shown how breathing motions in the enzyme facilitate the displacement of substrate from the surface of the enzyme to the buried active site. The most recent work points to the complex and spatially extensive nature of such motions and suggests possible modes of regulation of the activity of the enzyme.

  3. 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...

  4. Acetylcholinesterase: From 3D Structure to Function

    Dvir, Hay; Silman, Israel; Harel, Michal; Rosenberry, Terrone L.; Sussman, Joel L.

    2010-01-01

    By rapid hydrolysis of the neurotransmitter, acetylcholine, acetylcholinesterase terminates neurotransmission at cholinergic synapses. Acetylcholinesterase is a very fast enzyme, functioning at a rate approaching that of a diffusion-controlled reaction. The powerful toxicity of organophosphate poisons is attributed primarily to their potent inhibition of acetylcholinesterase. Acetylcholinesterase inhibitors are utilized in the treatment of various neurological disorders, and are the principal...

  5. Disulfide bonds of acetylcholinesterase

    The positions of the inter- and intrasubunit disulfide bridges were established for the 11S form of acetylcholinesterase (AChE) isolated from Torpedo californica. A major form of AChE localized within the basal lamina of the synapse is a dimensionally asymmetric molecule which contains either two (13S) or three (17S) sets of catalytic subunits linked to collagenous and non-collagenous structural subunits. Limited proteolysis yields a tetramer of catalytic subunits which sediments at 11S. Each catalytic subunit contains 8 cysteine residues. Initially, these Cys residues were identified following trypsin digestion of the reduced protein alkylated with [14C]-iodoacetate. Peptides were resolved by gel filtration followed by reverse phase HPLC. To determine the disulfide bonding profile, native non-reduced 11S AChE was treated with a fluorescent, sulfhydryl-specific reagent, monobromobimane, prior to proteolytic digestion. One fluorescent Cys peptide was identified indicating that a single sulfhydryl residue was present in its reduced form. Three pairs of disulfide bonded peptides were identified, sequenced, and localized in the polypeptide chain. The Cys residue that is located in the C-terminal tryptic peptide was disulfide bonded to an identical peptide and thus forms the intersubunit crosslink. Finally, the cysteine positions have been compared with the sequence of the homologous protein, thyroglobulin. Both likely share a common pattern of folding

  6. 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.

  7. Acetylcholinesterase: Enhanced Fluctuations and Alternative

    Bui, Jennifer M.; Tai, Kaihsu; Mccammon, J Andrew A.

    2004-05-21

    A 15 ns molecular dynamics simulation is reported for the complex of mouse acetylcholinesterase (mAChE) and the protein neurotoxin fasciculin-2. As compared to a 15 ns simulation of apo-mAChE, the structural fluctuations of the enzyme are substantially increased in magnitude for the enzyme in the complex. Fluctuations of part of the long omega loop (residues 69-96) are particularly enhanced. This loop forms one wall of the active site, and the enhanced fluctuations lead to additional routes of access to the active site.

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

    Alžběta Kračmarová; Lucie Drtinová; Miroslav Pohanka

    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 choli...

  9. Cyanobacterial secondary metabolites as acetylcholinesterase inhibitors

    Zelík, Petr; Masojídek, Jiří; Štys, Dalibor; Kopecký, Jiří

    Kunming : Verlag, 2006, s. 52-53. [International Conference on Applied Phycology /10./. Kunming (CN), 24.07.2005-28.07.2005] Institutional research plan: CEZ:AV0Z50200510 Keywords : cyanobacteria * acetylcholinesterase inhibitors Subject RIV: EE - Microbiology, Virology

  10. Irreversible thermal denaturation of Torpedo californica acetylcholinesterase.

    Kreimer, D. I.; Shnyrov, V. L.; Villar, E.; Silman, I.; Weiner, L

    1995-01-01

    Thermal denaturation of Torpedo californica acetylcholinesterase, a disulfide-linked homodimer with 537 amino acids in each subunit, was studied by differential scanning calorimetry. It displays a single calorimetric peak that is completely irreversible, the shape and temperature maximum depending on the scan rate. Thus, thermal denaturation of acetylcholinesterase is an irreversible process, under kinetic control, which is described well by the two-state kinetic scheme N-->D, with activation...

  11. Histochemical demonstration of acetylcholinesterase in neuroblastoma.

    Variend, S; Loughlin, M A

    1984-01-01

    The presence of acetylcholinesterase in the tumour cells of neuroblastoma has been shown by enzyme histochemistry. For comparison, some other tumours likely to be found in children and commonly presenting histologically as small cell tumours have also been studied. Acetylcholinesterase activity was seen in rhabdomyosarcoma, but, compared with neuroblastoma, the activity was focal and sparse. One Ewing's tumour and a lymphoblastic lymphoma were negative for the enzyme reaction. Some of the ult...

  12. 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.

  13. Use of acetylcholinesterase inhibitors in Alzheimer's disease.

    Moghul, S; Wilkinson, D

    2001-09-01

    Alzheimer's disease is a growing problem in an aging Western world, estimated to have cost the US economy USD 1.75 trillion. Until recently, the management of Alzheimer's disease largely comprised support for the family, nursing care and the use of unlicensed medication to control behavioral disturbances. The three new acetylcholinesterase inhibitors licensed to treat Alzheimer's disease (donepezil, rivastigmine and galantamine) have provided clinicians with a major impetus to their desire to diagnose and treat this lethal disease. Their effects on cognition are proven. More recent work on the effects of acetylcholinesterase inhibitors on behavioral symptoms, activities of daily living and caregiver burden have also been encouraging. Emerging work indicates their likely efficacy in other dementias (e.g., vascular dementia, dementia with Lewy bodies). This review summarizes the evidence concerning the impact of acetylcholinesterase inhibitors in dementia both currently and over the next 5 years. PMID:19811047

  14. Inactivation of acetylcholinesterase by various fluorophores

    Guo, Lilu; Suarez, Alirica I.; Thompson, Charles M.

    2010-01-01

    The inhibition of recombinant mouse acetylcholinesterase (rMAChE) and electric eel acetylcholinesterase (EEAChE) by seven, structurally different chromophore-based (dansyl, pyrene, dabsyl, diethylamino- and methoxycoumarin, Lissamine rhodamine B, and Texas Red) propargyl carboxamides or sulfonamides was studied. Diethylaminocoumarin, Lissamine, and Texas Red amides inhibited rMAChE with IC50 values of 1.00 µM, 0.05 µM, and 0.70 µM, respectively. Lissamine and Texas Red amides inhibited EEAChE...

  15. Acetylcholinesterase and Butyrylcholinesterase Inhibited by Paraoxon

    Kuča, K.; Musilová, L.; Paleček, J.; Církva, Vladimír; Paar, M.; Musílek, K.; Hrabinová, M.; Pohanka, M.; Zdarová Karasová, J.; Jun, D.

    2009-01-01

    Roč. 14, č. 12 (2009), s. 4915-4921. ISSN 1420-3049 Grant ostatní: MO0(CZ) FZV0000604 Institutional research plan: CEZ:AV0Z40720504 Keywords : acetylcholinesterase * reactivator * oxime Subject RIV: CC - Organic Chemistry Impact factor: 1.738, year: 2009

  16. ACETYLCHOLINESTERASE HISTOCHEMISTRY OF THE THALAMUS IN THE PRIMATE

    2001-01-01

    Objective To observe the distribution of acetylcholinesterase activity in the thalamus of the monkey.Methods Histochemical method was used to detect the acetylcholinesterase activity in the thalamus.Results Acetylcholinesterase was found to be inhomogeneous distribution in the primate thalamus and to reveal previously uncovered inhomogeneity within certain thalamic nuclei and their subdivisions. The medial, ventral and posterior nuclear groups displayed markedly uneven acetylcholinesterase reaction.In the mediodorsal nucleus,three distinct sbudivisions were revealed by acetylcholinesterase histochemistry, medial magnocellular part, ventral sector of central parvicellular part and dorsolateral sector of lateral pars multiformity showed weak, moderate and strong acetylcholinesterase activity, respectively. In the ventral nuclear group, acetylcholinesterase histochemistry was strong in the medial part of ventral posterior nucleus, moderate in the magnocellular part of ventral anterior, caudal, medial, oral and pars postrema parts of ventral lateral nucleus, as well as lateral part of ventral posterior nucleus, poor and weak in the inferior part of ventral posterior nucleus, par compacta of the medial part of ventral posterior nucleus and parvicellular part of ventral anterior nucleus. In the pulvinar nucleus, acetylcholinesterase reaction ranged from weak, moderate to strong in the parts of the oral, medial and lateral, as well as inferior of this nucleus, respectively. Regional variations of acetylcholinesterase activity within the thalamic nuclei and their subdivisions can help to identify them by acetylcholinesterase histochemistry. In addition, the dark patches of strong acetylcholinesterase activity contrasting with a lighter surrounding matrix were revealed within the parvicellular part and pars multiformis of mediodorsal nucleus, paracentral nucleus, central lateral nucleus, pars postrema part of ventral lateral nucleus and medial habenula nucleus, as well as

  17. 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.

  18. Altered Levels of Acetylcholinesterase in Alzheimer Plasma

    García Ayllón, María Salud; Riba Llena, Iolanda; Serra Basante, Carol; Alom, Jordi; Boopathy, Rathnam; Sáez-Valero, Javier

    2010-01-01

    Background Many studies have been conducted in an extensive effort to identify alterations in blood cholinesterase levels as a consequence of disease, including the analysis of acetylcholinesterase (AChE) in plasma. Conventional assays using selective cholinesterase inhibitors have not been particularly successful as excess amounts of butyrylcholinesterase (BuChE) pose a major problem. Principal Findings Here we have estimated the levels of AChE activity in human plasma by first imm...

  19. Inhibitors of Acetylcholinesterase and Butyrylcholinesterase Meet Immunity

    Miroslav Pohanka

    2014-01-01

    Acetylcholinesterase (AChE) inhibitors are widely used for the symptomatic treatment of Alzheimer’s disease and other dementias. More recent use is for myasthenia gravis. Many of these inhibitors interact with the second known cholinesterase, butyrylcholinesterase (BChE). Further, evidence shows that acetylcholine plays a role in suppression of cytokine release through a “cholinergic anti-inflammatory pathway” which raises questions about the role of these inhibitors in the immune system. Thi...

  20. A simple radiometric in vitro assay for acetylcholinesterase inhibitors

    A radiometric method for screening acetylcholinesterase inhibitors has been described. The method is based on the production of [14C]carbon dioxide from the hydrolysis of acetylcholine. The inhibitory concentration at 50% (IC50) values for several known acetylcholinesterase inhibitors were in agreement with literature values. The new radiometric method is simple, inexpensive, and has the potential for automation

  1. Acetylcholinesterase: diffusional encounter rate constants for dumbbell models of ligand.

    Antosiewicz, J; Gilson, M K; Lee, I H; McCammon, J A

    1995-01-01

    For some enzymes, virtually every substrate molecule that encounters the entrance to the active site proceeds to reaction, at low substrate concentrations. Such diffusion-limited enzymes display high apparent bimolecular rate constants ((kcat/KM)), which depend strongly upon solvent viscosity. Some experimental studies provide evidence that acetylcholinesterase falls into this category. Interestingly, the asymmetric charge distribution of acetylcholinesterase, apparent from the crystallograph...

  2. Acetylcholinesterase-inhibiting Alkaloids from Zephyranthes concolor

    Sebastien Arseneau

    2011-11-01

    Full Text Available The bulbs and aerial parts of Zephyranthes concolor (Lindl. Benth. & Hook. f. (Amaryllidaceae, an endemic species to Mexico, were found to contain the alkaloids chlidanthine, galanthamine, galanthamine N-oxide, lycorine, galwesine, and epinorgalanthamine. Since currently only partial and low resolution 1H-NMR data for chlidanthine acetate are available, and none for chlidanthine, its 1D and 2D high resolution 1H- and 13C-NMR spectra were recorded. Unambiguous assignations were achieved with HMBC, and HSQC experiments, and its structure was corroborated by X-ray diffraction. Minimum energy conformation for structures of chlidanthine, and its positional isomer galanthamine, were calculated by molecular modelling. Galanthamine is a well known acetylcholinesterase inhibitor; therefore, the isolated alkaloids were tested for this activity. Chlidanthine and galanthamine N-oxide inhibited electric eel acetylcholinesterase (2.4 and 2.6 × 10−5 M, respectively, indicating they are about five times less potent than galanthamine, while galwesine was inactive at 10−3 M. Inhibitory activity of HIV-1 replication, and cytotoxicity of the isolated alkaloids were evaluated in human MT-4 cells; however, the alkaloids showed poor activity as compared with standard anti-HIV drugs, but most of them were not cytotoxic.

  3. Temperature and pressure adaptation of the binding site of acetylcholinesterase.

    Hochachka, P W

    1974-12-01

    1. Studies with a carbon substrate analogue, 3,3-dimethylbutyl acetate, indicate that the hydrophobic contribution to binding at the anionic site of acetylcholinesterase is strongly disrupted at low temperatures and high pressures. 2. Animals living in different physical environments circumvent this problem by adjusting the enthalpic and entropic contributions to binding. 3. An extreme example of this adaptational strategy is supplied by brain acetylcholinesterase extracted from an abyssal fish living at 2 degrees C and up to several hundred atmospheres of pressure. This acetylcholinesterase appears to have a smaller hydrophobic binding region in the anionic site, playing a measurably decreased role in ligand binding. PMID:4462739

  4. Inhibitors of Acetylcholinesterase and Butyrylcholinesterase Meet Immunity

    Miroslav Pohanka

    2014-06-01

    Full Text Available Acetylcholinesterase (AChE inhibitors are widely used for the symptomatic treatment of Alzheimer’s disease and other dementias. More recent use is for myasthenia gravis. Many of these inhibitors interact with the second known cholinesterase, butyrylcholinesterase (BChE. Further, evidence shows that acetylcholine plays a role in suppression of cytokine release through a “cholinergic anti-inflammatory pathway” which raises questions about the role of these inhibitors in the immune system. This review covers research and discussion of the role of the inhibitors in modulating the immune response using as examples the commonly available drugs, donepezil, galantamine, huperzine, neostigmine and pyridostigmine. Major attention is given to the cholinergic anti-inflammatory pathway, a well-described link between the central nervous system and terminal effector cells in the immune system.

  5. Inhibitors of acetylcholinesterase and butyrylcholinesterase meet immunity.

    Pohanka, Miroslav

    2014-01-01

    Acetylcholinesterase (AChE) inhibitors are widely used for the symptomatic treatment of Alzheimer's disease and other dementias. More recent use is for myasthenia gravis. Many of these inhibitors interact with the second known cholinesterase, butyrylcholinesterase (BChE). Further, evidence shows that acetylcholine plays a role in suppression of cytokine release through a "cholinergic anti-inflammatory pathway" which raises questions about the role of these inhibitors in the immune system. This review covers research and discussion of the role of the inhibitors in modulating the immune response using as examples the commonly available drugs, donepezil, galantamine, huperzine, neostigmine and pyridostigmine. Major attention is given to the cholinergic anti-inflammatory pathway, a well-described link between the central nervous system and terminal effector cells in the immune system. PMID:24893223

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

    Remya, C.; K V Dileep; I Tintu; Variyar, E. J.; Sadasivan, C.

    2014-01-01

    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 acetylc...

  7. Acetylcholinesterase-R increases germ cell apoptosis but enhances sperm motility

    Mor, I.; Sklan, EH; Podoly, E; Pick, M; Kirschner, M.; Yogev, L.; Bar-Sheshet Itach, S; Schreiber, L; B. Geyer; Mor, T.; Grisaru, D.; Soreq, H.

    2008-01-01

    Abstract Changes in protein subdomains through alternative splicing often modify protein-protein interactions, altering biological processes. A relevant example is that of the stress-induced up-regulation of the acetylcholinesterase (AChE-R) splice variant, a common response in various tissues. In germ cells of male transgenic TgR mice, AChE-R excess associates with reduced sperm differentiation and sperm counts. To explore the mechanism(s) by which AChE-R up-regulation affects spermatogenesi...

  8. The Effects of Exercise-induced Fatigue on Acetylcholinesterase Expression and Activity at Rat Neuromuscular Junctions

    Wen, Guo; Hui, Wang; Dan, Chen; Xiao-Qiong, Wu; Jian-Bin, Tong; Chang-Qi, Li; De-Liang, Lei; Wei-Jun, Cai; Zhi-Yuan, Li; Xue-Gang, Luo

    2009-01-01

    Acetylcholinesterase is the enzyme that terminates neurotransmission by hydrolyzing the acetylcholine released by the motoneurons at the neuromuscular junctions. Although acetylcholinesterase has been studied for almost a century, the underlying relationship between exercise-induced fatigue and acetylcholinesterase activity at the synaptic cleft is not clear. The purpose of this study was to assess the effects of exercise-induced fatigue on the expression and activity of acetylcholinesterase ...

  9. Mutation at codon 322 in the human acetylcholinesterase (ACHE) gene accounts for YT blood group polymorphism.

    Bartels, C F; Zelinski, T; Lockridge, O

    1993-01-01

    Acetylcholinesterase is present in innervated tissues, where its function is to terminate nerve impulse transmission. It is also found in the red blood cell membrane, where its function is unknown. We report the first genetic variant of human acetylcholinesterase and support the identity of acetylcholinesterase as the YT blood group antigen. DNA sequencing shows that the wild-type sequence of acetylcholinesterase with His322 (CAC) is the YT1 blood group antigen and that the rare variant of ac...

  10. Antioxidative/acetylcholinesterase inhibitory activity of some Asteraceae plants.

    Mekinić, Ivana Generalić; Burcul, Franko; Blazević, Ivica; Skroza, Danijela; Kerum, Daniela; Katalinić, Visnja

    2013-04-01

    The extracts obtained by 80% EtOH from some Asteraceae plants (Calendula officinalis, Inula helenium, Arctium lappa, Artemisia absinthium and Achillea millefolium) were studied. Rosmarinic acid, one of the main compounds identified in all extracts, was determined quantitatively by using HPLC. In addition, spectrophotometric methods were evaluated as an alternative for rosmarinic acid content determination. Total phenolic content was also established for all extracts. A. millefolium extract was found to have the highest content of rosmarinic acid as well as total phenols. All extracts were tested for antioxidant and acetylcholinesterase inhibitory activity. A. millefolium was shown to possess the best antioxidant activity (for all tested methods) as well as acetylcholinesterase inhibitory activity. Highly positive linear relationships were obtained between antioxidant/acetylcholinesterase inhibitory activity and the determined rosmarinic acid content indicating its significance for the observed activities. PMID:23738456

  11. 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.

  12. Altered levels of acetylcholinesterase in Alzheimer plasma.

    María-Salud García-Ayllón

    Full Text Available BACKGROUND: Many studies have been conducted in an extensive effort to identify alterations in blood cholinesterase levels as a consequence of disease, including the analysis of acetylcholinesterase (AChE in plasma. Conventional assays using selective cholinesterase inhibitors have not been particularly successful as excess amounts of butyrylcholinesterase (BuChE pose a major problem. PRINCIPAL FINDINGS: Here we have estimated the levels of AChE activity in human plasma by first immunoprecipitating BuChE and measuring AChE activity in the immunodepleted plasma. Human plasma AChE activity levels were approximately 20 nmol/min/mL, about 160 times lower than BuChE. The majority of AChE species are the light G(1+G(2 forms and not G(4 tetramers. The levels and pattern of the molecular forms are similar to that observed in individuals with silent BuChE. We have also compared plasma AChE with the enzyme pattern obtained from human liver, red blood cells, cerebrospinal fluid (CSF and brain, by sedimentation analysis, Western blotting and lectin-binding analysis. Finally, a selective increase of AChE activity was detected in plasma from Alzheimer's disease (AD patients compared to age and gender-matched controls. This increase correlates with an increase in the G(1+G(2 forms, the subset of AChE species which are increased in Alzheimer's brain. Western blot analysis demonstrated that a 78 kDa immunoreactive AChE protein band was also increased in Alzheimer's plasma, attributed in part to AChE-T subunits common in brain and CSF. CONCLUSION: Plasma AChE might have potential as an indicator of disease progress and prognosis in AD and warrants further investigation.

  13. The Dynamics of Ligand Barrier Crossing Inside the Acetylcholinesterase Gorge

    Bui, Jennifer M.(University of California, San Diego); Henchman, Richard H.(University of California, San Diego); Mccammon, Andy (University of California, San Diego)

    2003-10-01

    The dynamics of ligand movement through the constricted region of the acetylcholinesterase gorge is important in understanding how the ligand gains access to and is released from the active site of the enzyme. Molecular dynamics simulations of the simple ligand, tetramethylammonium, crossing this bottleneck region are conducted using umbrella potential sampling and activated .ux techniques. The low potential of mean force obtained is consistent with the fast reaction rate of acetylcholinesterase observed experimentally. From the results of the activated dynamics simulations, local conformational .uctuations of the gorge residues and larger scale collective motions of the protein are found to correlate highly with the ligand crossing.

  14. NEUROTOXICITY OF PARATHION-INDUCED ACETYLCHOLINESTERASE INHIBITION IN NEONATAL RATS

    The biochemical and morphological neurotoxic effects of postnatal acetylcholinesterase (AChE) inhibition were examined in rat pups dosed with parathion, at time points critical to hippocampal neurogenesis and synaptogenesis (i.e., D5-20). ippocampal cytopathology as assessed by l...

  15. Inhibition of acetylcholinesterase activity by essential oil from Citrus paradisi.

    Miyazawa, M; Tougo, H; Ishihara, M

    2001-01-01

    Inhibition of acetylcholinesterase (AChE) activity by essential oils of Citrus paradisi (grapefruit pink in USA) was studied. Inhibition of AChE was measured by the colorimetric method. Nootkatone and auraptene were isolated from C. paradisi oil and showed 17-24% inhibition of AChE activity at the concentration of 1.62 microg/mL. PMID:11858553

  16. Complexity of acetylcholinesterases in biting flies and ticks

    Acetylcholinesterase (AChE) inhibitors function as pesticides for invertebrates, vertebrate nerve agents, and medicine to reduce cognitive effects of Alzheimer’s disease. Organophosphate (OP) pesticides have been widely used to control biting flies and ticks, however, OP-resistance has compromised c...

  17. 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.

  18. 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.

  19. Presence of a soluble form of acetylcholinesterase in human ocular fluids.

    Appleyard, M E; McDonald, B.; Benjamin, L

    1991-01-01

    Samples of ocular fluid obtained from normal persons at necropsy and during eye surgery have been assayed for the presence of acetylcholinesterase. Measurable levels could be detected in all samples examined, but levels of acetylcholinesterase in vitreous humour were consistently higher than those in aqueous humour, indicating a possible retinal origin. Polyacrylamide gel electrophoresis revealed that the enzyme of ocular fluid had the same mobility as that of acetylcholinesterase from cerebr...

  20. Three-dimensional structures of Drosophila melanogaster acetylcholinesterase and of its complexes with two potent inhibitors.

    Harel, M; Kryger, G.; Rosenberry, T. L.; Mallender, W. D.; Lewis, T.; Fletcher, R. J.; Guss, J.M.; Silman, I.; Sussman, J. L.

    2000-01-01

    We have crystallized Drosophila melanogaster acetylcholinesterase and solved the structure of the native enzyme and of its complexes with two potent reversible inhibitors, 1,2,3,4-tetrahydro-N-(phenylmethyl)-9-acridinamine and 1,2,3,4-tetrahydro-N-(3-iodophenyl-methyl)-9-acridinamine--all three at 2.7 A resolution. The refined structure of D. melanogaster acetylcholinesterase is similar to that of vertebrate acetylcholinesterases, for example, human, mouse, and fish, in its overall fold, char...

  1. A human acetylcholinesterase gene identified by homology to the Ace region of Drosophila.

    Soreq, H.; Zevin-Sonkin, D; Avni, A.; Hall, L. M.; Spierer, P

    1985-01-01

    The Ace locus of the Drosophila genome controls biosynthesis of the neurotransmitter-hydrolyzing enzyme acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7). We injected the mRNA species hybridizing with DNA fragments from this region into Xenopus oocytes, in which acetylcholinesterase mRNA is translated into active acetylcholinesterase. A 2.0-kilobase (kb) fragment of DNA from this region selectively hybridizes with Drosophila mRNA capable of inducing the biosynthesis of acetylch...

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

    Lamouroux Lucille; Lougarre Andrée; Siadat Omid; Ladurantie Caroline; Fournier Didier

    2006-01-01

    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 p...

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

    M. Julia Arcos-Martínez; Olga Domínguez-Renedo; Silvia Sanllorente-Méndez

    2010-01-01

    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 concen...

  4. Development of translationally active mRNA for larval muscle acetylcholinesterase during ascidian embryogenesis.

    Meedel, T H; Whittaker, J R

    1983-01-01

    Relative quantities of translationally active acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7) mRNA present at various developmental stages were compared in embryos of the ascidian Ciona intestinalis. Purified RNA was tested for its translational capacity by microinjection into Xenopus laevis oocytes; the acetylcholinesterase produced was immunoprecipitated with antibody to Ciona acetylcholinesterase and enzyme activity was assayed radiometrically. With this protocol, enzyme s...

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

    2014-01-01

    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 an...

  6. Resistance-associated point mutations in insecticide-insensitive acetylcholinesterase.

    Mutero, A; Pralavorio, M; Bride, J M; D. Fournier

    1994-01-01

    Extensive utilization of pesticides against insects provides us with a good model for studying the adaptation of a eukaryotic genome to a strong selective pressure. One mechanism of resistance is the alteration of acetylcholinesterase (EC 3.1.1.7), the molecular target for organophosphates and carbamates. Here, we report the sequence analysis of the Ace gene in several resistant field strains of Drosophila melanogaster. This analysis resulted in the identification of five point mutations asso...

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

    Anders Jens; Pietsch Stefan; Bauer Heike I; Kluge Harald H; Kluge Wolfram H; Venbrocks Rudolf A

    2001-01-01

    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 Pharmaco...

  8. Acetylcholinesterase Biosensors for Electrochemical Detection of Organophosphorus Compounds: A Review

    Vikas Dhull; Anjum Gahlaut; Neeraj Dilbaghi; Vikas Hooda

    2013-01-01

    The exponentially growing population, with limited resources, has exerted an intense pressure on the agriculture sector. In order to achieve high productivity the use of pesticide has increased up to many folds. These pesticides contain organophosphorus (OP) toxic compounds which interfere with the proper functioning of enzyme acetylcholinesterase (AChE) and finally affect the central nervous system (CNS). So, there is a need for routine, continuous, on spot detection of OP compounds which ar...

  9. Latent acetylcholinesterase in secretory vesicles isolated from adrenal medulla

    Gratzl, Manfred; Krieger-Brauer, H.; Ekerdt, R

    1981-01-01

    A new procedure is described for the preparation of highly purified and stable secretory vesicles from adrenal medulla. Two forms of acetylcholinesterase, a membrane bound form as well as a soluble form, were found within these vesicles. The secretory vesicles, isolated by differential centrifugation, were further purified on a continuous isotonic Percoll™ gradient. In this way, secretory vesicles were separated from mitochondrial, microsomal and cell membrane contamination. The secretory ves...

  10. Geranylphenazinediol, an Acetylcholinesterase Inhibitor Produced by aStreptomycesSpecies

    Ohlendorf, Birgit; Schulz, Dirk; Erhard, Arlette; Nagel, Kerstin; Imhoff, Johannes F.

    2012-01-01

    Geranylphenazinediol (1), a new phenazine natural product, was produced by the Streptomyces sp. strain LB173, which was isolated from a marine sediment sample. The structure was established by analysis of NMR and MS data. 1 inhibited the enzyme acetylcholinesterase in the low micromolar range and showed weak antibacterial activity. In order to get a more detailed picture of the activity profile of 1, its inhibitory potential was compared to that of related structures

  11. The Dynamics of Ligand Barrier Crossing inside the Acetylcholinesterase Gorge

    Bui, Jennifer M.; Henchman, Richard H.; McCammon, J. Andrew

    2003-01-01

    The dynamics of ligand movement through the constricted region of the acetylcholinesterase gorge is important in understanding how the ligand gains access to and is released from the active site of the enzyme. Molecular dynamics simulations of the simple ligand, tetramethylammonium, crossing this bottleneck region are conducted using umbrella potential sampling and activated flux techniques. The low potential of mean force obtained is consistent with the fast reaction rate of acetylcholineste...

  12. Conformational preferences of a 14-residue fibrillogenic peptide from acetylcholinesterase

    Vijayan, Ranjit; Biggin, Philip C

    2010-01-01

    A 14-residue fragment from near the C-terminus of the enzyme acetylcholinesterase (AChE) is believed to have a neurotoxic/neurotrophic effect acting via an unknown pathway. While the peptide is α-helical in the full-length enzyme, the structure and association mechanism of the fragment are unknown. Using multiple molecular dynamics simulations, starting from a tetrameric complex of the association domain of AChE and systematically disassembled subsets that include the peptide fragment, we sho...

  13. Effects of gamma radiation on solutions of acetylcholinesterase

    Dilute solutions of bovine erythrocyte acetylcholinesterase were irradiated by 30, 60, 90, and 120 krad of 60Co gamma rays under air at around 50C. The enzyme activity decreased progressively with radiation dose. Ultraviolet spectra measurements indicated conformational changes in the enzyme with radiation dose. Part of the decrease in the activity of the enzyme after irradiation by 120 krad could be accounted for by the splitting of the enzyme into two pieces of molecular weights 73,000 and 7500

  14. Binding partners for mouse acetylcholinesterase in the central nervous system

    Paraoanu, Laura Elena

    2004-01-01

    Acetylcholinesterase (AChE) is the enzyme that hydrolyses the neurotransmitter acetylcholine at the cholinergic synapses. Besides this principal role, called the classical function, AChE shows also other non-classical functions related to processes during embryonic development and diseases. The existence of multiple molecular forms, the homology with other neuronal cell adhesion molecules, and the early expression pattern, suggest that AChE may function in cell adhesion, and thus in neurite g...

  15. Functional redundancy of acetylcholinesterase and neuroligin in mammalian neuritogenesis

    Grifman, Mirta; Galyam, Nilly; Seidman, Shlomo; Soreq, Hermona

    1998-01-01

    Accumulated evidence attributes noncatalytic morphogenic activitie(s) to acetylcholinesterase (AChE). Despite sequence homologies, functional overlaps between AChE and catalytically inactive AChE-like cell surface adhesion proteins have been demonstrated only for the Drosophila protein neurotactin. Furthermore, no mechanism had been proposed to enable signal transduction by AChE, an extracellular enzyme. Here, we report impaired neurite outgrowth and loss of neurexin Iα mRNA under antisense s...

  16. Acetylcholinesterase Clustering at the Neuromuscular Junction Involves Perlecan and Dystroglycan

    Peng, H. Benjamin; Xie, Hongbo; Rossi, Susanna G.; Rotundo, Richard L.

    1999-01-01

    Formation of the synaptic basal lamina at vertebrate neuromuscular junction involves the accumulation of numerous specialized extracellular matrix molecules including a specific form of acetylcholinesterase (AChE), the collagenic-tailed form. The mechanisms responsible for its localization at sites of nerve– muscle contact are not well understood. To understand synaptic AChE localization, we synthesized a fluorescent conjugate of fasciculin 2, a snake α-neurotoxin that tightly binds to the ca...

  17. Asymmetric acetylcholinesterase is assembled in the Golgi apparatus.

    Rotundo, R. L.

    1984-01-01

    The synthesis, assembly, and processing of the multiple molecular forms of acetylcholinesterase (AcChoEase; acetylcholine acetylhydrolase, EC 3.1.1.7) in quail muscle cultures was studied by using lectins to distinguish enzyme molecules residing in different subcellular compartments. Special emphasis was given to the assembly of asymmetric AcChoEase molecules because these appear to be the predominant, if not unique, forms of AcChoEase at the vertebrate neuromuscular junction. All cell surfac...

  18. Geranylphenazinediol, an acetylcholinesterase inhibitor produced by a Streptomyces species.

    Ohlendorf, Birgit; Schulz, Dirk; Erhard, Arlette; Nagel, Kerstin; Imhoff, Johannes F

    2012-07-27

    Geranylphenazinediol (1), a new phenazine natural product, was produced by the Streptomyces sp. strain LB173, which was isolated from a marine sediment sample. The structure was established by analysis of NMR and MS data. 1 inhibited the enzyme acetylcholinesterase in the low micromolar range and showed weak antibacterial activity. In order to get a more detailed picture of the activity profile of 1, its inhibitory potential was compared to that of related structures. PMID:22775474

  19. Enzymatic and biochemical characterization of Bungarus sindanus snake venom acetylcholinesterase

    M Ahmed

    2012-01-01

    Full Text Available This study analyses venom from the elapid krait snake Bungarus sindanus, which contains a high level of acetylcholinesterase (AChE activity. The enzyme showed optimum activity at alkaline pH (8.5 and 45ºC. Krait venom AChE was inhibited by substrate. Inhibition was significantly reduced by using a high ionic strength buffer; low ionic strength buffer (10 mM PO4 pH 7.5 inhibited the enzyme by 1. 5mM AcSCh, while high ionic strength buffer (62 mM PO4 pH 7.5 inhibited it by 1 mM AcSCh. Venom acetylcholinesterase was also found to be thermally stable at 45ºC; it only lost 5% of its activity after incubation at 45ºC for 40 minutes. The Michaelis-Menten constant (Km for acetylthiocholine iodide hydrolysis was found to be 0.068 mM. Krait venom acetylcholinesterase was also inhibited by ZnCl2, CdCl2, and HgCl2 in a concentrationdependent manner. Due to the elevated levels of AChE with high catalytic activity and because it is more stable than any other sources, Bungarus sindanus venom is highly valuable for biochemical studies of this enzyme.

  20. Induction of plasma acetylcholinesterase activity in mice challenged with organophosphorus poisons

    The restoration of plasma acetylcholinesterase activity in mice following inhibition by organophosphorus pesticides and nerve agents has been attributed to synthesis of new enzyme. It is generally assumed that activity levels return to normal, are stable and do not exceed the normal level. We have observed over the past 10 years that recovery of acetylcholinesterase activity levels in mice treated with organophosphorus agents (OP) exceeds pretreatment levels and remains elevated for up to 2 months. The most dramatic case was in mice treated with tri-cresyl phosphate and tri-ortho-cresyl phosphate, where plasma acetylcholinesterase activity rebounded to a level 250% higher than the pretreatment activity. The present report summarizes our observations on plasma acetylcholinesterase activity in mice treated with chlorpyrifos, chlorpyrifos oxon, diazinon, tri-ortho-cresyl phosphate, tri-cresyl phosphate, tabun thiocholine, parathion, dichlorvos, and diisopropylfluorophosphate. We have developed a hypothesis to explain the excess acetylcholinesterase activity, based on published observations. We hypothesize that acetylcholinesterase activity is induced when cells undergo apoptosis and that consequently there is a rise in the level of plasma acetylcholinesterase. - Highlights: → Acetylcholinesterase activity is induced by organophosphorus agents. → AChE induction is related to apoptosis. → Induction of AChE activity by OP is independent of BChE.

  1. Surface display and bioactivity of Bombyx mori acetylcholinesterase on Pichia pastoris

    To construct the Pichia pastoris (P. pastoris) cell surface display system of Bombyx mori acetylcholinesterase (BmAChE), the gene for the anchor protein (AGa1) was obtained from Saccharomyces cerevisiae and was fused with the modified Bombyx mori acetylcholinesterase gene (bmace) and transformed int...

  2. High Efficiency Acetylcholinesterase Immobilization on DNA Aptamer Modified Surfaces

    Orada Chumphukam; Thao T. Le; Cass, Anthony E. G.

    2014-01-01

    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 ...

  3. Acetylcholinesterase Modulates Presenilin-1 Levels and γ-Secretase Activity

    Campanari, María-Letizia; García Ayllón, María Salud; Belbin, Olivia; Galcerán, Joan; Lleó, Alberto; Sáez-Valero, Javier

    2014-01-01

    The cholinergic enzyme acetylcholinesterase (AChE) and the catalytic component of the ¿-secretase complex, presenilin-1 (PS1), are known to interact. In this study, we investigate the consequences of AChE-PS1 interactions, particularly the influence of AChE in PS1 levels and ¿-secretase activity. PS1 is able to co-immunoprecipitate all AChE variants (AChE-R and AChE-T) and molecular forms (tetramers and light subunits) present in the human brain. Overexpression of AChE-R or AChE-T, or their r...

  4. Assembly and regulation of acetylcholinesterase at the vertebrate neuromuscular junction

    Rotundo, R. L.; Ruiz, C.A.; Marrero, E.; Kimbell, L. M.; Rossi, S.G.; Rosenberry, T.; Darr, A; Tsoulfas, P.

    2008-01-01

    The collagen-tailed form of acetylcholinesterase (ColQ-AChE) is the major if not unique form of the enzyme associated with the neuromuscular junction (NMJ). This enzyme form consists of catalytic and non-catalytic subunits encoded by separate genes, assembled as three enzymatic tetramers attached to the three-stranded collagen-like tail (ColQ). This synaptic form of the enzyme is tightly attached to the basal lamina associated with the glycosaminoglycan perlecan. Fasciculin-2 is a snake toxin...

  5. Production of the Acetylcholinesterase Inhibitor from Yarrowia lipolytica S-3

    Lee, Dae-Hyung; Lee, Ji-Su; Yi, Sung-Hun; Lee, Jong-Soo

    2008-01-01

    The acetylcholinesterase (AChE) inhibitor of Yarrowia lipolytica S-3 was maximally produced when it was incubated at 30℃ for 36 h in an optimal medium containing 1% yeast extract, 2% peptone and 2% glucose, with an initial pH 6.0. The final AChE inhibitory activity under these conditions was an IC50 value of 64 mg/ml. After partial purification of the AChE inhibitor by means of systematic solvent extraction, the final IC50 value of the partially purified AChE inhibitor was 0.75 mg/ml. We prep...

  6. Anti-Acetylcholinesterase Alkaloids from Annona glabra Leaf.

    Lee, Shoei-Sheng; Wu, Dong-Yi; Tsai, Sheng-Fa; Chen, Chien-Kuang

    2015-06-01

    Bioassay guided fractionation and separation of the EtOH extract of Annona glabra leaf against acetylcholinesterse led to the characterization of 15 alkaloids. Among them, (-)-actinodaphnine (2) and (-)-(6aS,7R)-7-hydroxyactinodaphnine (9) are new aporphines, although (+)-2 and (±)-2 have been found in several plants. Their structures were established by spectroscopic analysis. (-)-Anolobine (5) and (-)-roemeroline (8) showed moderate inhibitory activity against eel acetylcholinesterase with IC50 values of 22.4 and 26.3 μM, respectively. PMID:26197510

  7. ACETYLCHOLINESTERASE LEVELS IN FARMERS EXPOSED TO PESTICIDES IN MALAYSIA

    Ismarulyusda Ishak; Syarif Husin Lubis; Zariyantey Abd Hamid; Nihayah Mohammad; Hidayatulfathi Othman; Ahmad Rohi Ghazali; Muhammad Faiz Mohd Ismail; Shobna Sasitharan

    2015-01-01

    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...

  8. Imaging and acetylcholinesterase inhibitor response in dementia with Lewy bodies.

    Graff-Radford, Jonathan; Boeve, Bradley F; Pedraza, Otto; Ferman, Tanis J; Przybelski, Scott; Lesnick, Timothy G; Vemuri, Prashanthi; Senjem, Matthew L; Smith, Glenn E; Knopman, David S; Lowe, Val; Jack, Clifford R; Petersen, Ronald C; Kantarci, Kejal

    2012-08-01

    Acetylcholinesterase inhibitors are commonly used to treat patients with dementia with Lewy bodies. Hippocampal atrophy on magnetic resonance imaging and amyloid-β load on positron emission tomography are associated with the Alzheimer's disease-related pathology in patients with dementia with Lewy bodies. To date, few studies have investigated imaging markers that predict treatment response in patients with dementia with Lewy bodies. Our objective was to determine whether imaging markers of Alzheimer's disease-related pathology such as hippocampal volume, brain amyloid-β load on (11)C Pittsburgh compound B positron emission tomography predict treatment response to acetylcholinesterase inhibitors in patients with dementia with Lewy bodies. We performed a retrospective analysis on consecutive treatment-naive patients with dementia with Lewy bodies (n = 54) from the Mayo Clinic Alzheimer's Disease Research Centre who subsequently received acetylcholinesterase inhibitors and underwent magnetic resonance imaging with hippocampal volumetry. Baseline and follow-up assessments were obtained with the Mattis Dementia Rating Scale. Subjects were divided into three groups (reliable improvement, stable or reliable decline) using Dementia Rating Scale reliable change indices determined previously. Associations between hippocampal volumes and treatment response were tested with analysis of covariance adjusting for baseline Dementia Rating Scale, age, gender, magnetic resonance field strength and Dementia Rating Scale interval. Seven subjects underwent (11)C Pittsburgh compound B imaging within 12 weeks of magnetic resonance imaging. Global cortical (11)C Pittsburgh compound B retention (scaled to cerebellar retention) was calculated in these patients. Using a conservative psychometric method of assessing treatment response, there were 12 patients with reliable decline, 29 stable cases and 13 patients with reliable improvement. The improvers had significantly larger

  9. Acetylcholinesterase inhibitory effects of some plants from Rosaceae

    S. Esmaeili

    2015-10-01

    Full Text Available Background and objectives: Alzheimer's disease (AD is an age dependent disorder. AD is associated with decrease of brain acetylcholine level. Nowadays, one of the methods for progression inhibition of AD is using acetylcholinesterase inhibitors. Rosaceae is a large plant family. Different biological effects of some species of this family have been reported. The aim of the present study was to assess the acetylcholinesterase inhibitory (AChEI activity of the selected plants belonging to Rosaceae family. Methods: AChEI activity of six species from Rosaceae including Cotoneaster nummularia, Cerasus microcarpa, Amygdalus scoparia, Agrimonia eupatoria, Rosa canina and Rosa damascena were evaluated based on Ellman’s method in concentration of 300 µg/mL using total extracts and methanol fractions which were obtained by maceration. Results: The results showed that the total extract and methanol fraction of the aerial parts of A. eupatoria demonstrated significant AChEI activity with 46.5% and 56.2% inhibition of the enzyme, respectively. Conclusion: According to the results of the AChEI activity of the methanol fraction of A. eupatoria, it seems that the polar components of the species such as flavonoids may be responsible for its effectiveness.

  10. 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.

  11. A congenital myasthenic syndrome refractory to acetylcholinesterase inhibitors.

    Triggs, W J; Beric, A; Butler, I J; Roongta, S M

    1992-03-01

    We studied 4 siblings (3 men and 1 woman), ages 22 to 43 years, with congenital ptosis, external ophthalmoplegia, proximal muscle weakness and fatigability unresponsive to acetylcholinesterase (AChE) inhibitors. Repetitive nerve stimulation showed a significant compound muscle action potential (CMAP) area decrement at 2 or 3 Hz. Nerve conduction studies and concentric needle electromyography were normal, and repetitive CMAPs to single nerve stimulation were not observed. Voluntary single fiber electromyography (SFEMG) showed increased jitter and blocking. Assessment of individual end-plates using SFEMG with intramuscular axonal microstimulation showed no uniform relationship between jitter and the rate of stimulation, consistent with a postsynaptic defect of neuromuscular transmission. Edrophonium eliminated the decremental response to repetitive nerve stimulation, but caused no significant clinical improvement, suggesting an additional mechanism for weakness in these patients. PMID:1313543

  12. 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.

  13. 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.

  14. Effect of fluorocarbons on acetylcholinesterase activity and some counter measures

    Young, W.; Parker, J. A.

    1975-01-01

    An isolated vagal sympathetic heart system has been successfully used for the study of the effect of fluorocarbons (FCs) on cardiac performance and in situ enzyme activity. Dichlorodifluoromethane sensitizes this preparation to sympathetic stimulation and to exogenous epinephrine challenge. Partial and complete A-V block and even cardiac arrest have been induced by epinephrine challenge in the FC sensitized heart. Potassium chloride alone restores the rhythmicity but not the normal contractility of the heart in such a situation. Addition of glucose will, however, completely restore the normal function of the heart which is sensitized by dichlorodifluoromethane. The ED 50 values of acetylcholinesterase activity which are used as a measure of relative effectiveness of fluorocarbons are compared with the maximum permissible concentration. Kinetic studies indicate that all the fluorocarbons tested so far are noncompetitive.

  15. Enzymatic and biochemical characterization of Bungarus sindanus snake venom acetylcholinesterase

    Ahmed, M; Latif, N.; Khan RA; Ahmad, A.; JBT Rocha; CM Mazzanti; MD Bagatini; VM Morsch; MRC Schetinger

    2012-01-01

    This study analyses venom from the elapid krait snake Bungarus sindanus, which contains a high level of acetylcholinesterase (AChE) activity. The enzyme showed optimum activity at alkaline pH (8.5) and 45ºC. Krait venom AChE was inhibited by substrate. Inhibition was significantly reduced by using a high ionic strength buffer; low ionic strength buffer (10 mM PO4 pH 7.5) inhibited the enzyme by 1. 5mM AcSCh, while high ionic strength buffer (62 mM PO4 pH 7.5) inhibited it by 1 mM AcSCh. Venom...

  16. Interleukin 6 modulates acetylcholinesterase activity of brain neurons

    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)

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

    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 × LD50 and 1.5 × LD50 of toxin and 10 min 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 200 mg/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 26.7 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 exhibited its safety, tolerability

  18. 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

  19. N-[11C]methylpiperidine esters as acetylcholinesterase substrates: an in vivo structure-reactivity study

    A series of simple esters incorporating the N-[11C]methylpiperidine structure were examined as in vivo substrates for acetylcholinesterase in mouse brain. 4-N-[11C]Methylpiperidinyl esters, including the acetate, propionate and isobutyrate esters, are good in vivo substrates for mammalian cholinesterases. Introduction of a methyl group at the 4-position of the 4-piperidinol esters, to form the ester of a teritary alcohol, effectively blocks enzymatic action. Methylation of 4- N-[11C]methylpiperidinyl propionate at the 3-position gives a derivative with increased in vivo reactivity toward acetylcholinesterase. Esters of piperidinecarboxylic acids (nipecotic, isonipecotic and pipecolinic acid ethyl esters) are not hydrolyzed by acetylcholinesterase in vivo, nor do they act as in vivo inhibitors of the enzyme. This study has identified simple methods to both increase and decrease the in vivo reactivity of piperidinyl esters toward acetylcholinesterase

  20. Simultaneous ultrastructural visualization of acetylcholinesterase activity and tritiated norepinephrine uptake in renal nerves

    In this investigation we have combined the methods of ultrastructural demonstration of acetylcholinesterase activity with electron microscopic autoradiography for the demonstration of norepinephrine uptake. The results show electron-dense deposits indicative of acetylcholinesterase activity associated with perivascular axons overlaid by concentrations of silver grains representing exogenous tritiated norepinephrine. Forty-five percent of the intervaricose regions and 19% of the varicosities overlaid by autoradiographic grains showed ''moderate'' amounts of cholinesterase staining. A greater proportion of autoradiographic grains was observed on the varicosities than in the intervaricose regions; however, the amount of acetylcholinesterase activity was greater in the intervaricose regions than in the varicosities. This investigation provides evidence for the presence of periaxonal acetylcholinesterase staining in adrenergic axons in the rat kidney

  1. 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...

  2. Degree of inhibition of cortical acetylcholinesterase activity and cognitive effects by donepezil treatment in Alzheimer's disease

    Bohnen, N; Kaufer, D; Hendrickson, R; Ivanco, L; Lopresti, B; Koeppe, R; Meltzer, C; Constantine, G; Davis, J.; Mathis, C.; DeKosky, S; Moore, R.

    2005-01-01

    Objectives: To determine in vivo cortical acetylcholinesterase (AChE) activity and cognitive effects in subjects with mild Alzheimer's disease (AD, n = 14) prior to and after 12 weeks of donepezil therapy.

  3. A Biosensor Using Poly(4-Aminophenol)/acetylcholinesterase modified graphite electrode for the detection of dichlorvos

    Edmar Isaías Melo; Diego Leoni Franco; André Santiago Afonso; Hélen Cristine Rezende; Ana Graci Brito-Madurro; João Marcos Madurro; Nívia Maria Melo Coelho

    2011-01-01

    The properties of poly(4-aminophenol) modified graphite electrode as material for the immobilization of acetylcholinesterase were investigated by the Cyclic Voltammetry, Electrochemical Impedance Spectroscopy and Atomic Force Microscopy. The polymer was deposited on graphite electrode surface by the oxidation of 4-aminophenol and then acetylcholinesterase was immobilized on the surface of the electrode. The biosensor coupled in the continuous flow system was employed for the detection of dich...

  4. Antioxidant and acetylcholinesterase inhibitory potential of Arnica montana cultivated in Bulgaria

    Zheleva-Dimitrova, Dimitrina; BALABANOVA, Vessela

    2012-01-01

    The antioxidant and acetylcholinesterase inhibitory potential of methanol extract from Arnica montana cultivated in Bulgaria was evaluated. For the determination of antioxidant activity 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) di-ammonium salt (ABTS) free radicals, and ferric reducing antioxidant power (FRAP) assay were used. Modified Ellman's colorimetric method was used for quantitative assessment of acetylcholinesterase inhibiti...

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

    Andre-Michael Beer; Julian Lukanov; Yordanka Uzunova; Plamen Sagortchev

    2012-01-01

    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. M...

  6. Specific photoaffinity labeling induced by energy transfer: application to irreversible inhibition of acetylcholinesterase.

    Goeldner, M P; Hirth, C G

    1980-01-01

    p-Dimethylaminobenzene diazonium fluoroborate belongs to a class of potential photoaffinity labeling reagents which, by irradiation, produces a highly reactive electrophilic species. In addition, it can be photodecomposed by photoexcited tryptophan derivatives (e.g., N-acetyltryptophanamide and tryptophan residues belonging to acetylcholinesterase) by an energy transfer reaction. This substance is a competitive inhibitor of acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7) and ...

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

    Carlos Areche; Patricia Cejas; Pablo Thomas; Aurelio San-Martín; Luis Astudillo; Margarita Gutiérrez; Luis A Loyola

    2009-01-01

    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 i...

  9. Design, expression and characterization of mutants of fasciculin optimized for interaction with its target, acetylcholinesterase

    Sharabi, Oz; Peleg, Yoav; Mashiach, Efrat; Vardy, Eyal; Ashani, Yacov; Silman, Israel; Sussman, Joel L.; Shifman, Julia M.

    2009-01-01

    Predicting mutations that enhance protein–protein affinity remains a challenging task, especially for high-affinity complexes. To test our capability to improve the affinity of such complexes, we studied interaction of acetylcholinesterase with the snake toxin, fasciculin. Using the program ORBIT, we redesigned fasciculin's sequence to enhance its interactions with Torpedo californica acetylcholinesterase. Mutations were predicted in 5 out of 13 interfacial residues on fasciculin, preserving ...

  10. Phenolic Lipids Affect the Activity and Conformation of Acetylcholinesterase from Electrophorus electricus (Electric eel)

    Maria Stasiuk; Alicja Janiszewska; Arkadiusz Kozubek

    2014-01-01

    Phenolic lipids were isolated from rye grains, cashew nutshell liquid (CNSL) from Anacardium occidentale, and fruit bodies of Merrulius tremellosus, and their effects on the electric eel acetylcholinesterase activity and conformation were studied. The observed effect distinctly depended on the chemical structure of the phenolic lipids that were available for interaction with the enzyme. All of the tested compounds reduced the activity of acetylcholinesterase. The degree of inhibition varied, ...

  11. Quantitative and Qualitative Changes in the Skeletal Muscle Acetylcholinesterase Activity of Oreochromis niloticus Exposed to Methylparathion

    Elena Catap; Glorina Pocsidio

    1994-01-01

    Spectrophotometric assays and histochemical tests for acetylcholinesterase activity in the epaxial skeletal muscle of maturing Oreochromis niloticus after in-vivo exposure to 0.10 mg/L methylparathion showed significant inhibition of the enzyme by the pesticide. The assays manifested enzyme inhibition, after 48 and 96 hours of exposure, of 43.19% and 56.62%, respectively. These results were confirmed by the occurrences of decreased sites of acetylcholinesterase activity in the muscle fibers a...

  12. Distribution pattern of acetylcholinesterase in the optic tectum of two Indian air breathing teleosts

    Tripathi, Anurag; Rahman, Matiur; Chakraborty, Balarko

    2013-01-01

    Background A histoenzymological study has been carried out on the distribution of enzyme acetylcholinesterase in the optic tectum of two Indian air breathing teleosts by employing a histochemical technique to visualize acetylcholinesterase containing neurons described by Hedreen, JC (1985). Purpose Data available on enzyme localizaton in the brain of fishes, particularly Indian teleosts is inadequate and scattered. Methods AChE distribution in the optic tectum shows a prevalent pattern charac...

  13. Kolaviron, isolated from Garcinia kola, inhibits acetylcholinesterase activities in the hippocampus and striatum of wistar rats

    Ijomone, Omamuyovwi M.; Obi, Augustine U.

    2013-01-01

    Background Kolaviron, isolated from seeds of Garcinia kola, have been shown to possess wide pharmacological properties. Purpose The present study examined the effect of kolaviron on acetylcholinesterase activities in the hippocampus and striatum of adult Wistar rats. Methods In this study, histological and histochemical methods were used to investigate the effects of kolaviron on the histology of the hippocampus and striatum and on acetylcholinesterase activities in these brain regions. Resul...

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

    Trifone Schettino; Maria Elena Giordano; Antonio Calisi; Maria Giulia Lionetto; Roberto Caricato

    2013-01-01

    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 follo...

  15. Improvement of Drosophila acetylcholinesterase stability by elimination of a free cysteine

    Ladurantie Caroline; Arnaud Muriel; Brisson-Lougarre Andrée; Mazères Serge; Fremaux Isabelle; Fournier Didier

    2002-01-01

    Abstract Background Acetylcholinesterase is irreversibly inhibited by organophosphate and carbamate insecticides allowing its use for residue detection with biosensors. Drosophila acetylcholinesterase is the most sensitive enzyme known and has been improved by in vitro mutagenesis. However, it is not sufficiently stable for extensive utilization. It is a homodimer in which both subunits contain 8 cysteine residues. Six are involved in conserved intramolecular disulfide bridges and one is invo...

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

    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)

  17. IN VITRO INHIBITION OF ACETYLCHOLINESTERASE ACTIVITY IN HUMAN RED BLOOD CELLS BY CADMIUM AND LEAD

    Abdollahi, M.; M. Biukabadi M. A. Ebrahimzadeh

    1998-01-01

    The effects of cadmium and lead on human erythrocyte acetylcholinesterase activity were studied. Blood used in this study was obtained from 24 healthy individuals, then after hemolysation, treated with 3 various concentrations of cadmium and lead. A strong inhibition of acetylcholinesterase was noted in treated samples by cadmium and lead. The remaining activity In the case of lead, the remaining activity was found to be 81% with the highest concentration , S7% with the middle and 94% with th...

  18. 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)

  19. 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.

  20. A Comparative Analysis of Perinatal Development of Barrel Cortex in Rat, Mouse and Guinea Pig Using Acetylcholinesterase Histochemistry

    ŞENDEMİR, Erdoğan

    2000-01-01

    The role of acetylcholinesterase (AChE) in the developing neocortex was reexamined by comparing its expression in rats, mice and guinea pigs, following the protocol for acetylcholinesterase histochemistry (described in Sendemir et al., 1996) in order to determine the suitability of the breeding colony at UludaÛ University for use as an animal model. A total of 103 pups as well as two adult animals of each species were used. In the rat pups, acetylcholinesterase-rich patches were d...

  1. 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.

  2. Sarin Assay using Acetylcholinesterases and Electrochemical Sensor Strip

    Miroslav Pohanka

    2009-05-01

    Full Text Available An electrochemical sensor strip was used for sarin assay. Three different acetylcholinesterases (AChEs were chosen as promising recognition elements. viz., human recombinant, electric eel, and bovine erythrocytes origin. Human recombinant AChE seems to be the most sensitive to inhibition by sarin when the achieved limit of detection (0.45×10-8 mol/l and IC50 [(9.77± 8.08×10-6 mol/l] are considered. On the contrary, AChE from bovine erythrocytes proved to reach highest IC50 (5.37± 4.52×10-7 mol/l and the one from electric eel reached the highest limit of detection 0.93×10-8 mol/l. From the AChEs tested as biorecognition element, human recombinant seems to be the best for construction of new ChE detectors.Defence Science Journal, 2009, 59(3, pp.300-304, DOI:http://dx.doi.org/10.14429/dsj.59.1525

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

    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

  4. 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. PMID:25365355

  5. Acetylcholinesterase in the human erythron. III. Regulation of differentiation.

    Barr, R D; Koekebakker, M

    1990-08-01

    Acetylcholinesterase (AChE) is present in both primitive and mature erythroid cells, but a role for the enzyme in human hematopoiesis has not been defined. This prospect represented the primary objective of the following study. In clonal culture of normal human bone marrow cells, a "wave" of AChE activity was demonstrated, rising from undetectable levels to a peak (of 1.48 femto-moles per min per cell) at 10 days in the course of progressive erythroid clonogenesis. At concentrations of enzyme inhibitor that clearly reduced AChE activity in a dose-dependent fashion, there was no overall effect on erythropoiesis in vitro, but the clones were generally smaller and significantly more often multi-focal than in control cultures. Furthermore, in the presence of AChE inhibitors, a concentration-dependent increase in the myeloid-erythroid ratios of the culture harvests was observed. Likewise, a clear reduction in hemoglobination was revealed, in cells of 10 day cultures, from a mean hemoglobin concentration of 35.0 pg per cell in controls to 20.1 pg per cell in the presence of the maximal concentration of the inhibitor (10(-6) M eserine). These data point to a role for AChE in the regulation of differentiation in the human erythron. PMID:2368693

  6. 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.

  7. Efforts toward treatments against aging of organophosphorus-inhibited acetylcholinesterase.

    Zhuang, Qinggeng; Young, Amneh; Callam, Christopher S; McElroy, Craig A; Ekici, Özlem Dogan; Yoder, Ryan J; Hadad, Christopher M

    2016-06-01

    Aging is a dealkylation reaction of organophosphorus (OP)-inhibited acetylcholinesterase (AChE). Despite many studies to date, aged AChE cannot be reactivated directly by traditional pyridinium oximes. This review summarizes strategies that are potentially valuable in the treatment against aging in OP poisoning. Among them, retardation of aging seeks to lower the rate of aging through the use of AChE effectors. These drugs should be administered before AChE is completely aged. For postaging treatment, realkylation of aged AChE by appropriate alkylators may pave the way for oxime treatment by neutralizing the oxyanion at the active site of aged AChE. The other two strategies, upregulation of AChE expression and introduction of exogenous AChE, cannot resurrect aged AChE but may compensate for lowered active AChE levels by in situ production or external introduction of active AChE. Upregulation of AChE expression can be triggered by some peptides. Sources of exogenous AChE can be whole blood or purified AChE, either from human or nonhuman species. PMID:27327269

  8. Chemical Constituents and Acetylcholinesterase Inhibition of Senecio ventanensis Cabrera (Asteraceae

    Natalia Paola Alza

    2016-01-01

    Full Text Available Chemical constituents and acetylcholinesterase inhibition was investigated in both essential oil and dichloromethane subextract obtained from the aerial parts of Senecio ventanensis, an endemic Asteraceae. The chemical composition of the oil was determined by GC and GC-MS. The major constituents were a -terpinene (12.2%, limonene (11.9%, -humulene (10.5%, sabinene (9.1%, terpinolene (8.8%, p-cymene (8.1% and a -ocimene (7.3%. The bioassay guided isolation of the constituents of the active dichloromethane subextract (IC 50 = 361.6 µg/mL led us to the isolation of two diastereoisomers of a sesquiterpene endoperoxide 3,6-epidioxy-1,10-bisaboladiene (1 and 2, reported here for the first time in S. ventanensis. The identification was achieved by comprehensive analyses of its 1H and 13C NMR spectroscopic data (including 2D experiments and mass spectrometric data. Their absolute configuration is proposed on the basis of AM1 calculations and NOESY experiments. This is the first time that compounds 1 and 2 have been separated as well as the first phytochemical investigation of S. ventanensis.

  9. Perspectives for the structure-based design of acetylcholinesterase reactivators.

    Ochoa, Rodrigo; Rodriguez, Carlos A; Zuluaga, Andres F

    2016-07-01

    Rational design of active molecules through structure-based methods has been gaining adepts during the last decades due to the wider availability of protein structures, most of them conjugated with relevant ligands. Acetylcholinesterase (AChE) is a molecular target with a considerable amount of data related to its sequence and 3-dimensional structure. In addition, there are structural insights about the mechanism of action of the natural substrate and drugs used in Alzheimer's disease, organophosphorus compounds, among others. We looked for AChE structural data useful for in silico design of potential interacting molecules. In particular, we focused on information regarding the design of ligands aimed to reactivate AChE catalytic activity. The structures of 178 AChE were annotated and categorized on different subsets according to the nature of the ligand, source organisms and experimental details. We compared sequence homology among the active site from Torpedo californica, Mus musculus and Homo sapiens with the latter two species having the closest relationship (88.9% identity). In addition, the mechanism of organophosphorus binding and the design of effective reactivators are reviewed. A curated data collection obtained with information from several sources was included for researchers working on the field. Finally, a molecular dynamics simulation with human AChE indicated that the catalytic pocket volume stabilizes around 600 Å(3), providing additional clues for drug design. PMID:27450771

  10. Mechanism of Acetylcholinesterase Inhibition by Fasciculin: A 5-ns Molecular Dynamics Simulation

    Tai, Kaihsu; Shen, T Y.; Henchman, Richard H.; Bourne, Yves; Marchot, Pascale; Mccammon, Andy

    2002-05-01

    Our previous molecular dynamics simulation (10 ns) of mouse acetylcholinesterase (EC 3.1.1.7) revealed complex fluctuation of the enzyme active site gorge. Now we report a 5-ns simulation of acetylcholinesterase complexed with fasciculin 2. Fasciculin 2 binds to the gorge entrance of acetylcholinesterase with excellent complementarity and many polar and hydrophobic interactions. In this simulation of the protein-protein complex, where fasciculin 2 appears to sterically block access of ligands to the gorge, again we observe a two-peaked probability distribution of the gorge width. When fasciculin is present, the gorge width distribution is altered such that the gorge is more likely to be narrow. Moreover, there are large increases in the opening of alternative passages, namely, the side door (near Thr 75) and the back door (near Tyr 449). Finally, the catalytic triad arrangement in the acetylcholinesterase active site is disrupted with fasciculin bound. These data support that, in addition to the steric obstruction seen in the crystal structure, fasciculin may inhibit acetylcholinesterase by combined allosteric and dynamical means. Additional data from these simulations can be found at http://mccammon.ucsd.edu/.

  11. A Biosensor Using Poly(4-Aminophenol/acetylcholinesterase modified graphite electrode for the detection of dichlorvos

    Edmar Isaías Melo

    2011-12-01

    Full Text Available The properties of poly(4-aminophenol modified graphite electrode as material for the immobilization of acetylcholinesterase were investigated by the Cyclic Voltammetry, Electrochemical Impedance Spectroscopy and Atomic Force Microscopy. The polymer was deposited on graphite electrode surface by the oxidation of 4-aminophenol and then acetylcholinesterase was immobilized on the surface of the electrode. The biosensor coupled in the continuous flow system was employed for the detection of dichlorvos. The detection and quantification limits were 0.8 and 2.4 μmol L-1 dichlorvos, respectively. Graphite electrodes modified with the poly(4-aminophenol showed to be an efficient and promising material for immobilization of acetylcholinesterase enzyme. The proposed method requires simple parts which are easy to build, involves only one biosensor and the potentiometric detection is simple.

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

    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. (paper)

  13. 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.

  14. 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.

  15. Evaluation of acetylcholinesterase inhibitory activity of Brazilian red macroalgae organic extracts

    Levi P. Machado

    2015-12-01

    Full Text Available Abstract Alzheimer's disease affects nearly 36.5 million people worldwide, and acetylcholinesterase inhibition is currently considered the main therapeutic strategy against it. Seaweed biodiversity in Brazil represents one of the most important sources of biologically active compounds for applications in phytotherapy. Accordingly, this study aimed to carry out a quantitative and qualitative assessment of Hypnea musciformis (Wulfen J.V. Lamouroux, Ochtodes secundiramea (Montagne M.A. Howe, and Pterocladiella capillacea (S.G. Gmelin Santelices & Hommersand (Rhodophyta in order to determine the AChE effects from their extracts. As a matter of fact, the O. secundiramea extract showed 48% acetylcholinesterase inhibition at 400 μg/ml. The chemical composition of the bioactive fraction was determined by gas chromatography–mass spectrometry (GC–MS; this fraction is solely composed of halogenated monoterpenes, therefore allowing assignment of acetylcholinesterase inhibition activity to them.

  16. 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.

  17. Acetylcholinesterase in the human erythron. II. Biochemical assay.

    Barr, R D; Koekebakker, M; Lawson, A A

    1988-08-01

    Acetylcholinesterase (AChE) is an integral erythrocyte membrane protein. A role for the enzyme in the developing human erythron is being explored. Assays of AchE by the standard Ellman technique overestimate the amount of enzyme by failing to account for the contribution of hemoglobin to the optical density of the reaction mixture. Furthermore, reliance on substrate selection alone for specificity is unsatisfactory. Incorporation of inhibitors of "true" AchE and of pseudocholinesterase confer greater ability to distinguish one enzyme from the other. In our experience, the inhibitor constant (Kl) for edrophonium, which is highly specific for AChE, is approximately 5 x 10(-5) M against adult human erythrocytes that contain significantly more total cholinesterase activity than do erythrocytes from umbilical cord blood. This consists of both "true" and "pseudo" enzyme, the former predominating and accounting for 0.75-1.65 (mean 1.02, median 0.87) femtomoles of substrate hydrolysed per min per cell in adult blood, with values of 0.15-1.04 (mean 0.71, median 0.73) obtained on cord blood. Moreover, the enzyme activity in neonatal erythrocytes has a rather different inhibitor profile from that of adult cells. AChE was also demonstrated in fresh (ALL) and cultured (K562 and HL60) human leukemic cells, as well as in primitive granulocyte-macrophage and erythroid cells cloned from normal human bone marrow. In the erythroid colonies the enzyme activity was 0-3.76 (mean 1.20, median 0.76) femtomoles per min per cell, apparently the first successful measurement of AChE in such cells. PMID:3166338

  18. Changes of acetylcholinesterase activity in different brain areas of the rat following head irradiation

    Changes of acetylcholinesterase activity in rat hemispheres, brainstem, cerebellum and pontomedullar part following irradiation of the head with 7.0 Gy and 20.0 Gy, resp., were studied. The activity was increased after irradiation; the greatest changes of activity were observed in the hemispheres from the 2nd to the 7th day after irradiation and no changes in the cerebellum were detected. The acetylcholinesterase activity reached the normal level 10-30 days after irradiation. These results suggest that local irradiation of the head, beside other changes, caused a damage of the central cholinergic function. (author)

  19. Antigenic and structural differences in the catalytic subunits of the molecular forms of acetylcholinesterase.

    Doctor, B. P.; Camp, S; Gentry, M. K.; Taylor, S S; Taylor, P

    1983-01-01

    A mixture of the 5.6S hydrophobic dimer and the asymmetric, tail-containing (17 + 13)S forms of acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7) from Torpedo californica was used to immunize mice, and spleen cells from these mice were used to produce nine hybridoma lines secreting antibodies against acetylcholinesterase. Antibodies from one of the lines showed a 100-fold greater affinity for the 5.6S species when compared with the catalytic subunits of the (17 + 13)S species. ...

  20. Quantitative and Qualitative Changes in the Skeletal Muscle Acetylcholinesterase Activity of Oreochromis niloticus Exposed to Methylparathion

    Elena Catap

    1994-12-01

    Full Text Available Spectrophotometric assays and histochemical tests for acetylcholinesterase activity in the epaxial skeletal muscle of maturing Oreochromis niloticus after in-vivo exposure to 0.10 mg/L methylparathion showed significant inhibition of the enzyme by the pesticide. The assays manifested enzyme inhibition, after 48 and 96 hours of exposure, of 43.19% and 56.62%, respectively. These results were confirmed by the occurrences of decreased sites of acetylcholinesterase activity in the muscle fibers as exhibited upon performance of histochemical tests.

  1. Pharmacokinetics and pharmacodynamics of a novel Acetylcholinesterase Inhibitor, DMNG-3.

    Xin-Guo, Zhang; Kou, Fei; Guo-Di, Ma; Tang, Peng; Zhong-Duo, Yang

    2016-01-01

    DMNG-3(3β-Methyl-[2-(4-nitrophenoxy)ethyl]-amino]con-5-enine), is a new and the potentially most potent acetylcholinesterase inhibitor recently obtained from conessine by N-demethylation and nucleophilic substitution reaction. In the present study, a step-down passive avoidance test was used to investigate whether DMNG-3 could modulate impairment of learning and memory induced by scopolamine, and a high performance liquid chromatography(HPLC) method for the determination of DMNG-3 in biological samples was applied to study its pharmacokinetics and tissues distribution. Separation was achieved on C18 column using a mobile phase consisting methanol-water (70:30, v/v) at a flow rate of 1.0ml/min. The intra- and inter-day precisions were good and the RSD was all lower than 1.30%. The mean absolute recovery of DMNG-3 in plasma ranged from 88.55 to 96.45 %. Our results showed oral administration of DMNG-3(10,25,50 mg/kg/day) can significantly improve the latency and number of errors and had a positive effect of improvement of learning and memory in mice in passive avoidance tests. The elimination half-life (T1/2) was 14.07±1.29, 15.87±1.03h, and the total clearance (CL) values were 0.70±0.11, 0.78±0.13 L/h/kg, respectively. The pharmacokinetic studies showed that DMNG-3 has a slowly clearance and large distribution volume in experimental animals, and its disposition is linear over the range of doses tested. The liver, small intestine, stomach, and large intestine were the major distribution tissues of DMNG-3 in mice. It was found that DMNG-3 could be detected in brain, suggesting that DMNG-3 can cross the blood-brain barrier. The present study shows that DMNG-3 can be possible developed as a new drug for the treatment of Alzheimer's disease in the future. PMID:27373949

  2. Screening for acetylcholinesterase inhibitory activity in cyanobacteria of the genus Nostoc

    Zelík, Petr; Lukešová, Alena; Voloshko, L. N.; Štys, D.; Kopecký, Jiří

    2009-01-01

    Roč. 24, č. 2 (2009), s. 531-536. ISSN 1475-6366 R&D Projects: GA MŠk ME 874 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z60660521 Keywords : acetylcholinesterase * bioactivity * inhibitors Subject RIV: EE - Microbiology, Virology Impact factor: 1.496, year: 2009

  3. Effect of X-irradiation on acetylcholinesterase activity in the brain of mouse Mus booduga

    Acetylcholinesterase (AChE; E.C. 1.1.7) activity in the brain of lethally X-irradiated mouse, Mus booduga decreased progressively from 2 hours to 5 days of post-irradiation periods. A general loss of affinity to substrate during early days of post-irradiation, and a subsequent tendency towards normalization were noticed. (auth.)

  4. Synthesis of Some Phenylpropanoid Glycosides (PPGs) and Their Acetylcholinesterase/Xanthine Oxidase Inhibitory Activities

    Jin-Hui Wang; Xiao-Dong Li; Shuai-Tao Kang; Guo-Yu Li; Xian Li

    2011-01-01

    In this research, three categories of phenylpropanoid glycosides (PPGs) were designed and synthesized with PPGs isolated from Rhodiola rosea L. as lead compounds. Their inhibitory abilities toward acetylcholinesterase (AChE) and xanthine oxidase (XOD) were also tested. Some of the synthetic PPGs exhibited excellent enzyme inhibitory abilities.

  5. EFFECTS OF WATER POLLUTANTS AND OTHER CHEMICALS ON FISH ACETYLCHOLINESTERASE (IN VITRO)

    Acetylcholinesterase (AChE) preparations from the muscle of the fathead minnow (Pimephales promelas Rafinesque) were treated (in vitro) with 74 chemicals of various classes, many of which are environmental contaminants, to determine their effect upon enzyme activity. A highly inh...

  6. Synthesis of Some Phenylpropanoid Glycosides (PPGs and Their Acetylcholinesterase/Xanthine Oxidase Inhibitory Activities

    Jin-Hui Wang

    2011-04-01

    Full Text Available In this research, three categories of phenylpropanoid glycosides (PPGs were designed and synthesized with PPGs isolated from Rhodiola rosea L. as lead compounds. Their inhibitory abilities toward acetylcholinesterase (AChE and xanthine oxidase (XOD were also tested. Some of the synthetic PPGs exhibited excellent enzyme inhibitory abilities.

  7. Adenosine triphosphatase, acetylcholinesterase and sulfhydryl groups of rat skin at local x-ray irradiation

    The activity of acetylcholinesterase (ACE), adenosine triphosphatase (ATPase), and sulfhydryl groups(SH-groups) in different structural elements of skin in the course of radiation epidermitis was studied. The posterior extremities of Wistar rats were exposed to single x-ray irradiation at a dose of 30 Gy

  8. 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.

  9. Bifunctional phenolic-choline conjugates as anti-oxidants and acetylcholinesterase inhibitors

    Šebestík, Jaroslav; Marques, S. M.; Falé, P. L.; Santos, S.; Arduíno, D. M.; Cardoso, S. M.; Oliveira, S. M.; Serralheiro, M. L. M.; Santos, A. M.

    Roč. 26, č. 4 (485), s. 497. ISSN 1475-6366 Institutional research plan: CEZ:AV0Z40550506 Keywords : acetylcholinesterase inhibitors * antioxidants * hybrid ligands * anti-neurodegeneratives * Alzheimer´s disease Subject RIV: CC - Organic Chemistry

  10. The interaction of quaternary reversible acetylcholinesterase inhibitors with the nicotinic receptor

    Šepsová, V.; Krůšek, Jan; Zdarová Karasová, J.; Zemek, F.; Musílek, K.; Kuča, K.; Soukup, O.

    2014-01-01

    Roč. 63, č. 6 (2014), s. 771-777. ISSN 0862-8408 R&D Projects: GA ČR(CZ) GBP304/12/G069 Institutional support: RVO:67985823 Keywords : acetylcholinesterase inhibitor * nicotin receptor Subject RIV: ED - Physiology Impact factor: 1.293, year: 2014

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

    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

  12. 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.

  13. INHIBITION OF ACETYLCHOLINESTERASE IN ALZHEIMER’S DISEASE- AN IN SILICO APPROACH

    S. Aishwarya

    2012-05-01

    Full Text Available Alzheimer's disease (AD is a progressive degenerative disease of the brain marked by gradual and irreversible declines in cognitive functions. Acetylcholinesterase plays a biological role in the termination of nerve impulse transmissions at cholinergic synapses by rapid hydrolysis of acetylcholine. The deficit levels of acetylcholine lead to poor nerve impulse transmission. Thus the cholinesterase inhibitors would reverse the deficit in acetylcholine levels and consequently reverse the memory impairments characteristic of the disease. In the present work, functionalized coumarin compounds and their derivatives were docked into active site of Acetylcholinesterase using the docking programs GOLD and GLIDE. The compounds were screened using High throughput screening, and further subjected to Induced Fit Docking studies. Further, the QSAR studies revealed the best structure activity relationship and 100% of human oral absorption. The inhibitor compounds also satisfied the PASS (Prediction of Activity Spectra for Substances results of inhibiting the activity of acetylcholinesterase. The type of interaction they exhibit and the residues with which they interact convey that both the compounds are good inhibitors of Acetylcholinesterase as they exhibit drug like activity.

  14. 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

  15. Acetylcholinesterase Inhibition and Antioxidant Activity of Syzygium cumini, S. aromaticum and S. polyanthum from Indonesia

    Wulan Tri Wahyuni

    2013-01-01

    Full Text Available Acetylcholinesterase inhibition and antioxidant activity are considered to be highly correlated with Alzheimer’s disease treatment. Plants from Syzygium genus reported as potential antioxidant, however the potency of plants as acetylcholinesterase inhibitor has not been properly investigated. The present study was design to investigate the antioxidant and acetylcholinesterase inhibitory activity of three Syzygium plants, Syzygium cumini, S. aromaticum and S. polyanthum. Leaves of S. cumini, S. aromaticum, S. polyanthum and bud of S. aromaticum extracted with gradient polarity solvent consist of n-hexane, ethyl acetate and methanol. Acetylcholinesterase inhibitory activity was measured with modified Ellman method at 412 nm and physostigmine was used as positive control, meanwhile antioxidant activity measured based on 1,1-diphenyl-2-picrylhydrazil free radical scavenging test. The methanol extract of S. aromaticum leaves, S. aromaticum bud, S. polyanthum leaves and the ethyl acetate extract of S. polyanthum leaves were potential as acetylcholinesterase inhibitors. The IC50 values of the extracts respectively were 42.10±1.41; 45.25±0.07; 47.30±3.54 and 45.10±8.06 μg mL-1 when IC50 value of physostigmine was 0.01±0.002 μg mL-1. Meanwhile, antioxidant activity of potential extracts successively were 11.43±0.88, 9.26±0.25, 21.24±1.14 and 13.70±0.24 μg mL-1.

  16. An evaluation of the inhibition of human butyrylcholinesterase and acetylcholinesterase by the organophosphate chlorpyrifos oxon

    Acetylcholinesterase (EC 3.1.1.7) and butyrylcholinesterase (EC 3.1.1.8) are enzymes that belong to the superfamily of α/β-hydrolase fold proteins. While they share many characteristics, they also possess many important differences. For example, whereas they have about 54% amino acid sequence identity, the active site gorge of acetylcholinesterase is considerably smaller than that of butyrylcholinesterase. Moreover, both have been shown to display simple and complex kinetic mechanisms, depending on the particular substrate examined, the substrate concentration, and incubation conditions. In the current study, incubation of butyrylthiocholine in a concentration range of 0.005-3.0 mM, with 317 pM human butyrylcholinesterase in vitro, resulted in rates of production of thiocholine that were accurately described by simple Michaelis-Menten kinetics, with a Km of 0.10 mM. Similarly, the inhibition of butyrylcholinesterase in vitro by the organophosphate chlorpyrifos oxon was described by simple Michaelis-Menten kinetics, with a ki of 3048 nM-1 h-1, and a KD of 2.02 nM. In contrast to inhibition of butyrylcholinesterase, inhibition of human acetylcholinesterase by chlorpyrifos oxon in vitro followed concentration-dependent inhibition kinetics, with the ki increasing as the inhibitor concentration decreased. Chlorpyrifos oxon concentrations of 10 and 0.3 nM gave kis of 1.2 and 19.3 nM-1 h-1, respectively. Although the mechanism of concentration-dependent inhibition kinetics is not known, the much smaller, more restrictive active site gorge of acetylcholinesterase almost certainly plays a role. Similarly, the much larger active site gorge of butyrylcholinesterase likely contributes to its much greater reactivity towards chlorpyrifos oxon, compared to acetylcholinesterase.

  17. Concentration-dependent interactions of the organophosphates chlorpyrifos oxon and methyl paraoxon with human recombinant acetylcholinesterase

    For many decades it has been thought that oxygen analogs (oxons) of organophosphorus insecticides phosphorylate the catalytic site of acetylcholinesterase by a mechanism that follows simple Michaelis-Menten kinetics. More recently, the interactions of at least some oxons have been shown to be far more complex and likely involve binding of oxons to a second site on acetylcholinesterase that modulates the inhibitory capacity of other oxon molecules at the catalytic site. The current study has investigated the interactions of chlorpyrifos oxon and methyl paraoxon with human recombinant acetylcholinesterase. Both chlorpyrifos oxon and methyl paraoxon were found to have k i's that change as a function of oxon concentration. Furthermore, 10 nM chlorpyrifos oxon resulted in a transient increase in acetylthiocholine hydrolysis, followed by inhibition. Moreover, in the presence of 100 nM chlorpyrifos oxon, acetylthiocholine was found to influence both the K d (binding affinity) and k 2 (phosphorylation constant) of this oxon. Collectively, these results demonstrate that the interactions of chlorpyrifos oxon and methyl paraoxon with acetylcholinesterase cannot be described by simple Michaelis-Menten kinetics but instead support the hypothesis that these oxons bind to a secondary site on acetylcholinesterase, leading to activation/inhibition of the catalytic site, depending on the nature of the substrate and inhibitor. Additionally, these data raise questions regarding the adequacy of estimating risk of low levels of insecticide exposure from direct extrapolation of insecticide dose-response curves since the capacity of individual oxon molecules at low oxon levels could be greater than individual oxon molecules in vivo associated with the dose-response curve

  18. Modification of radiation damage to acetylcholinesterase of shadow red discs by changing the osmotic power of the irradiation medium

    The model of erythrocyte membrane acetylcholinesterase was used to study the effect of the ion medium osmotic power, created by KCl, on radiation inactivation and postradiation additional damage to the enzyme in the course of ageing of shadow red discs

  19. 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

    2016-01-01

    The physically adsorbed acetylcholinesterase on mesoporous silicon surface is presented. The catalytic behavior of immobilized enzyme was assessed by spectrophotometric bioassay. The immobilization enhanced the reusability, shelf life and thermal as well as pH stability

  20. 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...

  1. Determination of Acetylcholinesterase activities in marine gastropod (Morula granulata) as a biomarker of neurotoxic contaminants along the Goan coast.

    Sarkar, A.; Tegur, P.M.; Jana, S.; Rao, P.V.S.S.D.P.

    Acetylcholinesterase (AChE) is an enzyme that degrades the neurotransmitter acetylcholine, producing choline and acetate. group. It is mainly found at neuromuscular junctions and cholinergic synapses in the central nervous system, where its activity...

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

    Kamilla Monteiro dos Santos; Priscila Sant'Ana Gonçalves; Maria José Nunes de Paiva; Guilherme Araújo Lacerda

    2011-01-01

    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 inhibit...

  3. Histochemical diagnosis of Hirschsprung's disease and a comparison of the histochemical and biochemical activity of acetylcholinesterase in rectal mucosal biopsies.

    Patrick, W. J.; Besley, G T; Smith, I. I.

    1980-01-01

    Three hundred and seventy-two rectal mucosal biopsies, taken from 150 children and young adults with chronic constipation, were subjected to histochemical and biochemical analysis of acetylcholinesterase to excude Hirschsprung's disease. The relative merits of the procedures were compared. The histochemical method was considered to be the most practical for laboratories handling small numbers of biopsies but the biochemical estimation of acetylcholinesterase activity was found to be a useful ...

  4. alpha-Bungarotoxin labeling and acetylcholinesterase localization at the Mauthner fiber giant synapse in the hatchetfish

    Autoradiographic and histochemical techniques have been used to characterize further the pharmacology of transmission at the Mauthner fiber giant synapse of the South American hatchetfish. [125I]alpha-Bungarotoxin was applied to hatchetfish medullae and a standard autoradiographic procedure was carried out on 3- to 4-microns sections of glutaraldehyde-fixed tissue. All Mauthner fiber giant synapses, as identified by light microscopic criteria, had closely associated silver grains. Labeling was blocked by d-tubocurarine. Glutaraldehyde-fixed slices of hatchetfish medulla were stained histochemically for acetylcholinesterase; all giant synapses that could be identified in the light microscope showed heavy deposits of reaction product. Staining was blocked by diisopropyl-fluorophosphate, which inhibits both pseudocholinesterase and acetylcholinesterase, but was not blocked by tetraisopropylpyrophosphoramide, a specific pseudocholinesterase inhibitor. This evidence strongly supports the suggestion that the Mauthner fiber giant synapse is nicotinic cholinergic

  5. Alpha-Bungarotoxin labeling and acetylcholinesterase localization at the Mauthner fiber giant synapse in the hatchetfish

    Autoradiographic and histochemical techniques have been used to characterize further the pharmacology of transmission at the Mauthner fiber giant synapse of the South American hatchetfish. [125I]alpha-Bungarotoxin was applied to hatchetfish medullae and a standard autoradiographic procedure was carried out on 3- to 4-microns sections of glutaraldehyde-fixed tissue. All Mauthner fiber giant synapses, as identified by light microscopic criteria, had closely associated silver grains. Labeling was blocked by d-tubocurarine. Glutaraldehyde-fixed slices of hatchetfish medulla were stained histochemically for acetylcholinesterase; all giant synapses that could be identified in the light microscope showed heavy deposits of reaction product. Staining was blocked by diisopropyl-fluorophosphate, which inhibits both pseudocholinesterase and acetylcholinesterase, but was not blocked by tetraisopropylpyrophosphoramide, a specific pseudocholinesterase inhibitor. This evidence strongly supports the suggestion that the Mauthner fiber giant synapse is nicotinic cholinergic

  6. Measurement of acetylcholinesterase inhibition using bienzymes immobilized monolith micro-reactor with integrated electrochemical detection

    He Ping; Davies, Joanna; Greenway, Gillian [Department of Chemistry, University of Hull, Hull HU6 7RX (United Kingdom); Haswell, Stephen J., E-mail: s.j.haswell@hull.ac.uk [Department of Chemistry, University of Hull, Hull HU6 7RX (United Kingdom)

    2010-02-05

    This paper reports a simple {mu}-FIA based method for the rapid evaluation of acetylcholinesterase inhibition based on bienzymes immobilized monolith micro-reactor, with integrated electrochemical detection. The monolith was prepared inside a micro-fluidic device from two precursors TMOS and MTMOS using a sol-gel method, followed by PEI polymer functionalization and subsequent enzyme immobilization via electrostatic attraction between electronegative enzymes and electropositive PEI polymers. A bienzyme system containing co-immobilized acetylcholinesterase and choline oxidase was used for the evaluation of enzyme inhibition induced by malaoxon, eserine and methomyl analytes. The proposed method, which gave a LOD of 0.5, 0.2 and 1.0 {mu}M for malaoxon, eserine and methomyl repeatedly, was found to offer several advantages over existing systems including efficient enzyme immobilization, minimal reagent consumption and rapid analysis capability.

  7. Measurement of acetylcholinesterase inhibition using bienzymes immobilized monolith micro-reactor with integrated electrochemical detection

    This paper reports a simple μ-FIA based method for the rapid evaluation of acetylcholinesterase inhibition based on bienzymes immobilized monolith micro-reactor, with integrated electrochemical detection. The monolith was prepared inside a micro-fluidic device from two precursors TMOS and MTMOS using a sol-gel method, followed by PEI polymer functionalization and subsequent enzyme immobilization via electrostatic attraction between electronegative enzymes and electropositive PEI polymers. A bienzyme system containing co-immobilized acetylcholinesterase and choline oxidase was used for the evaluation of enzyme inhibition induced by malaoxon, eserine and methomyl analytes. The proposed method, which gave a LOD of 0.5, 0.2 and 1.0 μM for malaoxon, eserine and methomyl repeatedly, was found to offer several advantages over existing systems including efficient enzyme immobilization, minimal reagent consumption and rapid analysis capability.

  8. IN VITRO INHIBITION OF ACETYLCHOLINESTERASE ACTIVITY IN HUMAN RED BLOOD CELLS BY CADMIUM AND LEAD

    M. Abdollahi

    1998-08-01

    Full Text Available The effects of cadmium and lead on human erythrocyte acetylcholinesterase activity were studied. Blood used in this study was obtained from 24 healthy individuals, then after hemolysation, treated with 3 various concentrations of cadmium and lead. A strong inhibition of acetylcholinesterase was noted in treated samples by cadmium and lead. The remaining activity In the case of lead, the remaining activity was found to be 81% with the highest concentration , S7% with the middle and 94% with the lowest one (30 fi g/dl, p<0.05. Cadmium showed a nearly linear correlation between doses used and decrease in activity (r- = 0.S3, lead showed a better correlation (r- = 0.92. The direct effect of metal ions on AChE, i.e. a decrease in quantity of the enzyme, may be a proposed mechanism for this depression.

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

    Vinicius Viana Pereira

    2015-10-01

    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. Anchorage of collagen-tailed acetylcholinesterase to the extracellular matrix is mediated by heparan sulfate proteoglycans

    1985-01-01

    Heparan sulfate and heparin, two sulfated glycosaminoglycans (GAGs), extracted collagen-tailed acetylcholinesterase (AChE) from the extracellular matrix (ECM) of the electric organ of Discopyge tschudii. The effect of heparan sulfate and heparin was abolished by protamine; other GAGs could not extract the esterase. The solubilization of the asymmetric AChE apparently occurs through the formation of a soluble AChE-GAG complex of 30S. Heparitinase treatment but not chondroitinase ABC treatment ...

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

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

    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...

  12. Kinetics of Acetylcholinesterase Inhibition by an Aqueous Extract of Mentha longifolia Leaves

    Chandra Shekhar; Suresh Kumar

    2014-01-01

    Cholinesterase inhibitors are the class of compounds which inhibit cholinesterase enzyme. These are used as drugs for symptomatic treatment of Alzheimer’s disease (AD). The present study, evaluate anti-cholinesterase property of an aqueous extract of Mentha longifolia leaves, which is an aromatic plant traditionally used for several medicinal properties. Ellman’s method was used to determine the acetylcholinesterase (AChE) enzyme inhibitory activity of an aqueous extracts of Mentha longifolia...

  13. 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.

  14. Selective and Irreversible Inhibitors of Aphid Acetylcholinesterases: Steps Toward Human-Safe Insecticides

    Yuan-Ping Pang; Singh, Sanjay K.; Yang Gao; T Leon Lassiter; MISHRA, Rajesh K.; Kun Yan Zhu; Stephen Brimijoin

    2009-01-01

    Aphids, among the most destructive insects to world agriculture, are mainly controlled by organophosphate insecticides that disable the catalytic serine residue of acetylcholinesterase (AChE). Because these agents also affect vertebrate AChEs, they are toxic to non-target species including humans and birds. We previously reported that a cysteine residue (Cys), found at the AChE active site in aphids and other insects but not mammals, might serve as a target for insect-selective pesticides. Ho...

  15. Performance evaluation of acetylcholinesterase-based biosensors for detection of heavy metals

    David, Melinda; Badea, Mihaela; Florescu, Monica

    2011-01-01

    In this work, mediated carbon-ink screen-printed electrodes are used to develop enzyme-based biosensors for detection of selected heavy metals. Two immobilisation methods were used for acetylcholinesterase (AChE) immobilisation on electrode surface together with two redox mediators. The methods used for the encapsulation of the enzyme were: cross-linking with bi-functional reagents like glutar-aldehyde (GA) and encapsulation with sol-gel method.The used mediators were TCNQ (tetracianoqu...

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

    2013-01-01

    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 structure...

  17. Back-Scattering Interferometry: An Ultrasensitive Method for the Unperturbed Detection of Acetylcholinesterase-Inhibitor Interactions

    Haddad, Gabrielle L.; Young, Sherri C.; Heindel, Ned D.; Bornhop, Darryl J.; Flowers, Robert A.

    2012-01-01

    A series of inhibitors of acetylcholinesterase (AChE) have been screened by back-scattering interferometry (BSI). Enzyme levels as low as 100 pM (22,000 molecules of AChE) can be detected. This method can be used to screen for mixed AChE inhibitors, agents that have shown high efficacy against Alzheimer's disease, by detecting dual-binding interactions.

  18. The human gene encoding acetylcholinesterase is located on the long arm of chromosome 7.

    Getman, D K; Eubanks, J H; Camp, S; Evans, G.A.; Taylor, P

    1992-01-01

    Acetylcholinesterase (AChE) is a secreted enzyme essential for regulating cholinergic neurotransmission at neuronal and neuromuscular synapses. In view of the altered expression of AChE in some central neurological and neuromuscular disorders with a probable genetic basis, we have identified the chromosomal location of the gene encoding AChE. Chromosomal in situ suppression hybridization analysis revealed a single gene to be at 7q22, a result which was confirmed by PCR analysis of genomic DNA...

  19. Brain acetylcholinesterase activity is markedly reduced in dominantly-inherited olivopontocerebellar atrophy.

    Kish, S J; Schut, L; Simmons, J.; Gilbert, J.; Chang, L. J.; Rebbetoy, M

    1988-01-01

    The activity was measured of the acetylcholine catabolising enzyme acetylcholinesterase (AChE) in brain after necropsy of seven patients from one established pedigree with dominantly-inherited olivopontocerebellar atrophy (OPCA), a cerebellar ataxia disorder in which neuropathological changes are assumed to be primarily restricted to cerebellum, lower brain stem and spinal cord. Mean AChE activity was significantly reduced in cerebral (-51% to 65%) and cerebellar (-47%) cortex with a less sev...

  20. An electrostatic mechanism for substrate guidance down the aromatic gorge of acetylcholinesterase.

    Ripoll, D. R.; Faerman, C H; Axelsen, P H; Silman, I.; Sussman, J. L.

    1993-01-01

    Electrostatic calculations based on the recently solved crystal structure of acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7) indicate that this enzyme has a strong electrostatic dipole. The dipole is aligned with the gorge leading to its active site, so that a positively charged substrate will be drawn to the active site by its electrostatic field. Within the gorge, aromatic side chains appear to shield the substrate from direct interaction with most of the negatively charged...

  1. Wild Argentinian Amaryllidaceae, a New Renewable Source of the Acetylcholinesterase Inhibitor Galanthamine and Other Alkaloids

    Feresin, Gabriela E.; Jaume Bastida; Alejandro Tapia; German Roitman; Cristina Theoduloz; Strahil Berkov; Natalia B. Pigni; Javier E. Ortiz

    2012-01-01

    The Amaryllidaceae family is well known for its pharmacologically active alkaloids. An important approach to treat Alzheimer’s disease involves the inhibition of the enzyme acetylcholinesterase (AChE). Galanthamine, an Amaryllidaceae alkaloid, is an effective, selective, reversible, and competitive AchE inhibitor. This work was aimed at studying the alkaloid composition of four wild Argentinian Amarillydaceae species for the first time, as well as analyzing their inhibitory activity...

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

    2015-01-01

    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 doc...

  3. In vitro acetylcholinesterase inhibition by psoralen using molecular docking and enzymatic studies

    Gauresh Somani; Chinmay Kulkarni; Prashant Shinde; Rupesh Shelke; Kirti Laddha; Sadhana Sathaye

    2015-01-01

    Introduction: Alzheimer′s disease (AD) has increased at an alarming rate and is now a worldwide health problem. Inhibitors of acetylcholinesterase (AChE) leading to inhibition of acetylcholine breakdown constitute the main therapeutic strategy for AD. Psoralen was investigated as inhibitor of AChE enzyme in an attempt to explore its potential for the management of AD. Materials and Methods: Psoralen was isolated from powdered Psoralea corylifolia fruits. AChE enzyme inhibitory activity of dif...

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

    Vivek Kumar Gupta; Rajnish Pal; Nikhat Jamal Siddiqi; Bechan Sharma

    2015-01-01

    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 sugge...

  5. Evaluation of Acetylcholinesterase Biosensor Based on Carbon Nanotube Paste in the Determination of Chlorphenvinphos

    Oliveira, A. C.; Mascaro, L. H.

    2011-01-01

    An amperometric biosensor for chlorphenvinphos (organophosphorus pesticide) based on carbon nanotube paste and acetylcholinesterase enzyme (CNTs-AChE biosensor) is described herein. This CNTs-AChE biosensor was characterized by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The SEM result shows the presence of CNTs and small lumps, due to the enzyme AChE, which has a type of cauliflower formation. From EIS analysis is possible to observe increased R tc fo...

  6. Bioactive Paper Sensor Based on the Acetylcholinesterase for the Rapid Detection of Organophosphate and Carbamate Pesticides

    2014-01-01

    In many countries, people are becoming more concerned about pesticide residues which are present in or on food and feed products. For this reason, several methods have been developed to monitor the pesticide residue levels in food samples. In this study, a bioactive paper-based sensor was developed for detection of acetylcholinesterase (AChE) inhibitors including organophosphate and carbamate pesticides. Based on the Ellman colorimetric assay, the assay strip is composed of a paper support (1...

  7. A photonic crystal based sensing scheme for acetylcholine and acetylcholinesterase inhibitors

    Fenzl, Christoph; Genslein, Christa; Zöpfl, Alexander; Baeumner, Antje; Hirsch, Thomas

    2015-01-01

    We present a new scheme for sensing biomolecules by combining an enzyme hydrogel with a photonic crystal hydrogel layer that responds to ionic strength and pH changes. We demonstrate this unique combination by successfully detecting acetylcholine (ACh) and acetylcholinesterase (AChE) inhibitors. Specifically, the sandwich assembly is composed of layers of photonic crystals and a polyacrylamide hydrogel functionalized with AChE. The photonic crystal film has a red color and turns dark purple w...

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

    Rene Kizek; Vojtech Adam; Miroslav Pohanka

    2013-01-01

    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 desc...

  9. Screening the methanol extracts of some Iranian plants for acetylcholinesterase inhibitory activity

    Gholamhoseinian, A; Moradi, M.N.; Sharifi-far, F.

    2009-01-01

    Acetylcholinesterase (AChE) is the main enzyme for the breakdown of acetylcholine. Nowadays, usage of the inhibitors of this enzyme is one of the most important types of treatment of mild to moderate neurodegenerative diseases such as Alzheimer’s disease. Herbal medicines can be a new source of inhibitors of this enzyme. In this study we examined around 100 different plants to evaluate their inhibitory properties for AChE enzyme. Plants were scientifically identified and their extracts were p...

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

    Shuping Zhang; Shaoyang Li; Jie Ma; Fei Xiong; Song Qu

    2013-01-01

    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 i...

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

    Shen-Ming Chen; Arun Prakash Periasamy; Yogeswaran Umasankar

    2009-01-01

    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 su...

  12. How Is Acetylcholinesterase Phosphonylated by Soman? An Ab Initio QM/MM Molecular Dynamics Study

    Sirin, Gulseher Sarah; Zhang, Yingkai

    2014-01-01

    Acetylcholinesterase (AChE) is a crucial enzyme in the cholinergic nerve system that hydrolyzes acetylcholine (ACh) and terminates synaptic signals by reducing the effective concentration of ACh in the synaptic clefts. Organophosphate compounds irreversibly inhibit AChEs, leading to irreparable damage to nerve cells. By employing Born–Oppenheimer ab initio QM/MM molecular dynamics simulations with umbrella sampling, a state-of-the-art approach to simulate enzyme reactions, we have characteriz...

  13. Mouse Acetylcholinesterase Enhances Neurite Outgrowth of Rat R28 Cells Through Interaction With Laminin-1

    Sperling, Laura E.; Klaczinski, Janine; Schütz, Corina; Rudolph, Lydia; Layer, Paul G.

    2012-01-01

    The enzyme acetylcholinesterase (AChE) terminates synaptic transmission at cholinergic synapses by hydrolyzing the neurotransmitter acetylcholine, but can also exert ‘non-classical’, morpho-regulatory effects on developing neurons such as stimulation of neurite outgrowth. Here, we investigated the role of AChE binding to laminin-1 on the regulation of neurite outgrowth by using cell culture, immunocytochemistry, and molecular biological approaches. To explore the role of AChE, we examined fib...

  14. Cell surface acetylcholinesterase molecules on multinucleated myotubes are clustered over the nucleus of origin

    1992-01-01

    Multinucleated skeletal muscle fibers are compartmentalized with respect to the expression and organization of several intracellular and cell surface proteins including acetylcholinesterase (AChE). Mosaic muscle fibers formed from homozygous myoblasts expressing two allelic variants of AChE preferentially translate and assemble the polypeptides in the vicinity of the nucleus encoding the mRNA (Rotundo, R. L. 1990. J. Cell Biol. 110:715-719). To determine whether the locally synthesized AChE m...

  15. AhR-Mediated Effects of Dioxin on Neuronal Acetylcholinesterase Expression in Vitro

    Xie, Heidi Qunhui; Xu, Hai-ming; Fu, Hua-Ling; Hu, Qin; Tian, Wen-Jing; Pei, Xin-Hui; Zhao, Bin

    2013-01-01

    Background: Deficits in cognitive functioning have been reported in humans exposed to dioxins and dioxin-like compounds. Evidence suggests that dioxins induce cholinergic dysfunction mediated by hypothyroidism. However, little is known about direct effects of dioxins on the cholinergic system. Objectives: We investigated the action of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on acetylcholinesterase (AChE), a key enzyme in cholinergic neurotransmission. Methods: We used SK-N-SH human-derived...

  16. Basal lamina directs acetylcholinesterase accumulation at synaptic sites in regenerating muscle

    1985-01-01

    In skeletal muscles that have been damaged in ways which spare the basal lamina sheaths of the muscle fibers, new myofibers develop within the sheaths and neuromuscular junctions form at the original synaptic sites on them. At the regenerated neuromuscular junctions, as at the original ones, the muscle fibers are characterized by junctional folds and accumulations of acetylcholine receptors and acetylcholinesterase (AChE). The formation of junctional folds and the accumulation of acetylcholin...

  17. Excess “read-through” acetylcholinesterase attenuates but the “synaptic” variant intensifies neurodeterioration correlates

    Sternfeld, Meira; Shoham, Shai; Klein, Omer; Flores-Flores, Cesar; Evron, Tamah; Idelson, Gregory H.; Kitsberg, Dani; Patrick, James W.; Soreq, Hermona

    2000-01-01

    Acute stress increases the risk for neurodegeneration, but the molecular signals regulating the shift from transient stress responses to progressive disease are not yet known. The “read-through” variant of acetylcholinesterase (AChE-R) accumulates in the mammalian brain under acute stress. Therefore, markers of neurodeterioration were examined in transgenic mice overexpressing either AChE-R or the “synaptic” AChE variant, AChE-S. Several observations demonstrate that excess AChE-R attenuates,...

  18. In vitro inhibition of acetylcholinesterase by crude plant extracts from Colombian flora.

    Niño, Jaime; Hernández, Jimmy A; Correa, Yaned M; Mosquera, Oscar M

    2006-11-01

    The methanol extracts from five different plant families (Asteraceae, Euphorbiaceae, Melastomataceae, Rubiaceae, and Solanaceae) collected at Regional Natural Park Ucumarí (Colombia), were screened for their acetylcholinesterase inhibitory activity through the modified Ellman's spectrophotometric method. The best inhibitory activities on this study were shown by the extracts of Solanum leucocarpum Dunal (IC50 = 204.59 mg/l) and Witheringia coccoloboides (Damm) (IC50 = 220.68 mg/l), both plants belonging to the Solanaceae family. PMID:17160288

  19. Biochemical and cytochemical evidence indicates that coated vesicles in chick embryo myotubes contain newly synthesized acetylcholinesterase

    1985-01-01

    We have isolated highly purified coated vesicles from 17-d-old chick embryo skeletal muscle. These isolated coated vesicles contain acetylcholinesterase (AChE) in a latent, membrane-protected form as demonstrated enzymatically and morphologically using the Karnovsky and Roots histochemical procedure (J. Histochem. Cytochem., 1964, 12:219- 221). By the use of appropriate inhibitors the cholinesterase activity can be shown to be specific for acetylcholine. It also can be concluded that most of ...

  20. Inhibitory Effects of Sodium Arsenite and Acacia Honey on Acetylcholinesterase in Rats

    Aliyu Muhammad; Oyeronke A Odunola; Michael A. Gbadegesin; Sallau, Abdullahi B.; Ndidi, Uche S.; Ibrahim, Mohammed A.

    2015-01-01

    This study was conducted to investigate the effect of sodium arsenite and Acacia honey on acetylcholinesterase (AChE) activity and electrolytes in the brain and serum of Wistar rats. Male Wistar albino rats in four groups of five rats each were treated with distilled water, sodium arsenite (5 mg/kg body weight), Acacia honey (20% v/v), and sodium arsenite and Acacia honey, daily for one week. The sodium arsenite and Acacia honey significantly P

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

    Shin-Ichi Yokota; Kaai Nakamura; Midori Ando; Hiroyasu Kamei; Fumihiko Hakuno; Shin-Ichiro Takahashi; Shigenobu Shibata

    2014-01-01

    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 hepa...

  2. Some novel antimicrobial therapeutic agents for acetylcholinesterase inhibitors; synthesis of hydroxyquinoline ester involving amino acid

    Şakıyan, İffet; Aynacı, Elif; Arslan, Fatma; Öğütcü, Hatice; Sarı, Nurşen

    2015-01-01

    The aim of this work was to investigate the new effective agents candidate for treatment of the Alzheimer’s disease. So, a series of new and highly active acetylcholinesterase inhibitors derived from hydroxyquinoline ester containing amino acid were synthesized. Antibacterial activities of the molecules were studied by the well-diffusion method against Listeria monocytogenes 4b, Staphylococcus aureus, Escherichia coli, Salmonella typhi H, Brucella abortus, Staphylococcus epidermis sp., ...

  3. Applications of Integrated Data Mining Methods to Exploring Natural Product Space for Acetylcholinesterase Inhibitors

    Schuster, Daniela; Kern, Lisa; Hristozov, Dimitar P.; Terfloth, Lothar; Bienfait, Bruno; Laggner, Christian; Kirchmair, Johannes; Grienke, Ulrike; Wolber, Gerhard; Langer, Thierry; Stuppner, Hermann; Gasteiger, Johann; Rollinger, Judith M.

    2010-01-01

    Nature, especially the plant kingdom, is a rich source for novel bioactive compounds that can be used as lead compounds for drug development. In order to exploit this resource, the two neural network-based virtual screening techniques novelty detection with self-organizing maps (SOMs) and counterpropagation neural network were evaluated as tools for efficient lead structure discovery. As application scenario, significant descriptors for acetylcholinesterase (AChE) inhibitors were determined a...

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

    Sanda Vladimir-Knežević; Biljana Blažeković; Marija Kindl; Jelena Vladić; Lower-Nedza, Agnieszka D.; Brantner, Adelheid H.

    2014-01-01

    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 ...

  5. Irradiation inactivation analysis of acetylcholinesterase and the effect of buffer salts

    Loss of function of membrane-bound proteins after bombardment with ionizing radiation has been used to obtain information about the size of such proteins. Human erythrocyte ghosts are a convenient source of acetylcholinesterase, a membrane-bound enzyme which has been studied with this technique and so could be used as an internal standard for calibration with the high doses required. After freeze-drying from buffers containing Tris, Hepes, or Bicine, irradiation of erythrocyte ghosts with increasing doses of 16-MeV electrons gave size estimates for acetylcholinesterase of between 56,000 and 80,000 molecular weight. These values are similar to those that have been reported in the literature. However, erythrocyte ghosts freeze dried from phosphate buffer gave larger size estimates for acetylcholinesterase of about twice that found in the other buffers. This value was close to the molecular weight of 154,000 reported for the purified enzyme. The different sizes did not appear to be due to different ionic strengths. The implications of these results for the interpretation of data from irradiation inactivation analysis are discussed

  6. 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.

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

    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.

  8. 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.

  9. 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.

  10. Stressing hematopoiesis and immunity: an acetylcholinesterase window into nervous and immune system interactions

    Hermona Soreq

    2012-03-01

    Full Text Available Hematopoietic stem cells (HSC differentiate and generate all blood cell lineages while maintaining self renewal ability throughout life. Systemic responses to stressful insults, either psychological or physical exert both stimulating and down-regulating effects on these dynamic members of the immune system. Stress-facilitated division and re-oriented differentiation of progenitor cells modifies hematopoietic cell type composition, while enhancing cytokine production and promoting inflammation. Inversely, stress-induced increases in the neurotransmitter acetylcholine act to mitigate inflammatory response and regain homeostasis. This signaling process is terminated when acetylcholine is hydrolyzed by acetylcholinesterase. Alternative splicing, which is stress-modified, changes the composition of acetylcholinesterase variants, modifying their terminal sequences, susceptibility for microRNA suppression and sub-cellular localizations. Intriguingly, the effects of stress and acetylcholinesterase variants on hematopoietic development and inflammation in health and disease are both subject to small molecule as well as oligonucleotide-mediated manipulations in vitro and in vivo. The therapeutic agents can thus be targeted to the enzyme protein, its encoding mRNA transcripts or the regulator microRNA-132, opening new venues for therapeutic interference with multiple nervous and immune system diseases.

  11. 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.

  12. 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.

  13. 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.

  14. Interaction of lobed kudzuvine root, rhizoma chuanxiong with both acetylcholinesterase and beta-amyloid (Aβ1-42

    Li Shuai

    2013-01-01

    Full Text Available Background: Lobed kudzuvine root and rhizoma chuanxiong are effective drugs in traditional Chinese medicine. Objective: Extracts of the two medicines were investigated for their in vitro of beta-amyloid (Aβ1-42-aggregation-and acetylcholinesterase (AChE-inhibitory activities. Materials and Methods: The interaction of lobed kudzuvine root, rhizoma chuanxiong with both acetylcholinesterase and beta-amyloid (Aβ1-42 were studied by Michaelis-Menten equations, Thioflavin T (ThT fluorescence analysis and transmission electron microscope (TEM. Results: Inhibition of acetylcholinesterase showed that 1-butanol fraction of the two medicines were noncompetitive inhibition, apparent inhibition constants were 9.947 and 7.1523. ThT fluorescence analysis and TEM results indicated that inhibition of the water fraction and 1-butanol fraction (both lobed kudzuvine root and rhizoma chuanxiong was better. Conclusion: The result supported further research on chemical constituents and pharmacological mechanisms.

  15. Effect of Moringa oleifera flower extract on larval trypsin and acetylcholinesterase activities in Aedes aegypti.

    Pontual, Emmanuel Viana; Napoleão, Thiago Henrique; Dias de Assis, Caio Rodrigo; de Souza Bezerra, Ranilson; Xavier, Haroudo Satiro; Navarro, Daniela Maria do Amaral Ferraz; Coelho, Luana Cassandra Breitenbach Barroso; Paiva, Patrícia Maria Guedes

    2012-03-01

    Aedes aegypti control is crucial to reducing dengue fever. Aedes aegypti larvae have developed resistance to organophosporous insecticides and the use of natural larvicides may help manage larval resistance by increasing elements in insecticide rotation programs. Here, we report on larvicidal activity of Moringa oleifera flower extract against A. aegypti L(1), L(2), L(3), and L(4) as well as the effect of flower extract on gut trypsin and whole-larval acetylcholinesterase from L(4.) In addition, the heated flower extract was investigated for larvicidal activity against L(4) and effect on larval gut trypsin. Moringa oleifera flower extract contains a proteinaceous trypsin inhibitor (M. oleifera flower trypsin inhibitor, MoFTI), triterpene (β-amyrin), sterol (β-sitosterol) as well as flavonoids (kaempferol and quercetin). Larvicidal activity was detected against L(2), L(3), and L(4) (LC(50) of 1.72%, 1.67%, and 0.92%, respectively). Flower extract inhibited L(4) gut trypsin (MoFTI K(i) = 0.6 nM) and did not affect acetylcholinesterase activity. In vivo assay showed that gut trypsin activity from L(4) treated with M. oleifera flower extract decreased over time (0-1,440 min) and was strongly inhibited (98.6%) after 310 min incubation; acetylcholinesterase activity was not affected. Thermal treatment resulted in a loss of trypsin inhibitor and larvicidal activities, supporting the hypothesis that flower extract contains a proteinaceous trypsin inhibitor that may be responsible for the deleterious effects on larval mortality. PMID:22392801

  16. Selective effects of carbamate pesticides on rat neuronal nicotinic acetylcholine receptors and rat brain acetylcholinesterase

    Effects of commonly used carbamate pesticides on rat neuronal nicotinic acetylcholine receptors expressed in Xenopus laevis oocytes have been investigated using the two-electrode voltage clamp technique. The potencies of these effects have been compared to the potencies of the carbamates to inhibit rat brain acetylcholinesterase. The potency order of six carbamates to inhibit α4β4 nicotinic receptors is fenoxycarb > EPTC > carbaryl, bendiocarb > propoxur > aldicarb with IC50 values ranging from 3 μM for fenoxycarb to 165 μM for propoxur and >1 mM for aldicarb. Conversely, the potency order of these carbamates to inhibit rat brain acetylcholinesterase is bendiocarb > propoxur, aldicarb > carbaryl >> EPTC, fenoxycarb with IC50 values ranging from 1 μM for bendiocarb to 17 μM for carbaryl and >>1 mM for EPTC and fenoxycarb. The α4β2, α3β4, and α3β2 nicotinic acetylcholine receptors are inhibited by fenoxycarb, EPTC, and carbaryl with potency orders similar to that for α4β4 receptors. Comparing the potencies of inhibition of the distinct subtypes of nicotinic acetylcholine receptors shows that the α3β2 receptor is less sensitive to inhibition by fenoxycarb and EPTC. The potency of inhibition depends on the carbamate as well as on a combination of α and β subunit properties. It is concluded that carbamate pesticides affect different subtypes of neuronal nicotinic receptors independently of acetylcholinesterase inhibition. This implicates that neuronal nicotinic receptors are additional targets for some carbamate pesticides and that these receptors may contribute to carbamate pesticide toxicology, especially after long-term exposure

  17. 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.

  18. Structural basis of femtomolar inhibitors for acetylcholinesterase subtype selectivity: insights from computational simulations.

    Zhu, Xiao-Lei; Yu, Ning-Xi; Hao, Ge-Fei; Yang, Wen-Chao; Yang, Guang-Fu

    2013-04-01

    Acetylcholinesterase (AChE) is a key enzyme of the cholinergic nervous system. More than one gene encodes the synaptic AChE target. As the most potent known AChE inhibitor, the syn1-TZ2PA6 isomer was recently shown to have higher affinity as a reversible organic inhibitor of acetylcholinesterase1 (AChE1) than the anti1-TZ2PA6 isomer. Opposite selectivity has been shown for acetylcholinesterase2 (AChE2). In an attempt to understand the selectivity of the syn1-TZ2PA6 and anti1-TZ2PA6 isomers for AChE1 and AChE2, six molecular dynamics (MD) simulations were carried out with mouse AChE (mAChE, type of AChE1), Torpedo californica AChE (TcAChE, type of AChE1), and Drosophila melanogaster AChE (DmAChE, type of AChE2) bound with syn1-TZ2PA6 and anti1-TZ2PA6 isomers. Within the structure of the inhibitor, the 3,8-diamino-6-phenylphenanthridinium subunit and 9-amino-1,2,3,4-tetrahydroacridine subunit, via π-π interactions, made more favorable contributions to syn1-TZ2PA6 or anti1-TZ2PA6 isomer binding in the mAChE/TcAChE enzyme than the 1,2,3-triazole subunit. Compared to AChE1, the triazole subunit had increased binding energy with AChE2 due to a greater negative charge in the active site. The binding free energy calculated using the MM/PBSA method suggests that selectivity between AChE1 and AChE2 is mainly attributed to decreased binding affinity for the inhibitor. PMID:23500627

  19. Thermal denaturation of Bungarus fasciatus acetylcholinesterase: Is aggregation a driving force in protein unfolding?

    Shin, I; Wachtel, E; Roth, E; Bon, C; Silman, I; Weiner, L

    2002-08-01

    A monomeric form of acetylcholinesterase from the venom of Bungarus fasciatus is converted to a partially unfolded molten globule species by thermal inactivation, and subsequently aggregates rapidly. To separate the kinetics of unfolding from those of aggregation, single molecules of the monomeric enzyme were encapsulated in reverse micelles of Brij 30 in 2,2,4-trimethylpentane, or in large unilamellar vesicles of egg lecithin/cholesterol at various protein/micelle (vesicle) ratios. The first-order rate constant for thermal inactivation at 45 degrees C, of single molecules entrapped within the reverse micelles (0.031 min(-1)), was higher than in aqueous solution (0.007 min(-1)) or in the presence of normal micelles (0.020 min(-1)). This clearly shows that aggregation does not provide the driving force for thermal inactivation of BfAChE. Within the large unilamellar vesicles, at average protein/vesicle ratios of 1:1 and 10:1, the first-order rate constants for thermal inactivation of the encapsulated monomeric acetylcholinesterase, at 53 degrees C, were 0.317 and 0.342 min(-1), respectively. A crosslinking technique, utilizing the photosensitive probe, hypericin, showed that thermal denaturation produces a distribution of species ranging from dimers through to large aggregates. Consequently, at a protein/vesicle ratio of 10:1, aggregation can occur upon thermal denaturation. Thus, these experiments also demonstrate that aggregation does not drive the thermal unfolding of Bungarus fasciatus acetylcholinesterase. Our experimental approach also permitted monitoring of recovery of enzymic activity after thermal denaturation in the absence of a competing aggregation process. Whereas no detectable recovery of enzymic activity could be observed in aqueous solution, up to 23% activity could be obtained for enzyme sequestered in the reverse micelles. PMID:12142456

  20. 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.

  1. 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.

  2. 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.

  3. Influence of differential expression of acetylcholinesterase in brain and muscle on respiration

    Boudinot, Eliane; Bernard, Véronique; Camp, Shelley; Taylor, Palmer; Champagnat, Jean; Krejci, Eric; Foutz, Arthur S.

    2008-01-01

    A mouse strain with a deleted acetylcholinesterase (AChE) gene (AChE knockout) shows a decreased inspiration time and increased tidal volume and ventilation. To investigate the respective roles of AChE in brain and muscle, we recorded respiration by means of whole-body plethysmography in knockout mice with tissue selective deletions in AChE expression. A mouse strain with the anchoring domains of AChE deleted (del E5+6 knockout mice) has very low activity in the brain and neuromuscular juncti...

  4. 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.

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

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

    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...

  6. Pharmacological evaluation of [11c]donepezil as tracer for visualization of acetylcholinesterase by PET

    Donepezil is a highly potent and selective reversible acetylcholinesterase inhibitor. [11C]Donepezil is prepared by methylation with [11C]CH3I 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 11C-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

  7. Acetylcholinesterase-Inhibiting Activity of Pyrrole Derivatives from a Novel Marine Gliding Bacterium, Rapidithrix thailandica

    Khanit Suwanborirux; Anuchit Plubrukarn; Kornkanok Ingkaninan; Akkharawit Kanjana-opas; Supreeya Yuenyongsawad; Oraphan Sakulkeo; Yutthapong Sangnoi

    2008-01-01

    Acetylcholinesterase-inhibiting activity of marinoquinoline A (1), a new pyrroloquinoline from a novel species of a marine gliding bacterium Rapidithrix thailandica, was assessed (IC50 4.9 mM). Two related pyrrole derivatives, 3-(2'-aminophenyl)-pyrrole (3) and 2,2-dimethyl-pyrrolo-1,2-dihydroquinoline (4), were also isolated from two other strains of R. thailandica. The isolation of 3 froma natural source is reported here for the first time. Compound 4 was proposed to be an isolation artifac...

  8. The effect of dichlorvos on acetylcholinesterase activity in some tissues in rats

    Dere E.; Ari Ferda; Ugur S.

    2010-01-01

    In this study, the changes with respect to time in the serum, brain, liver, kidney and small intestine acetylcholinesterase activities were investigated in both male and female rats administered dichlorvos intraperitoneally (i.p.). For this purpose, 4 mg kg-1 doses of dichlorvos were injected i.p. in the rats. The control groups, on the other hand, were administered physiological saline via the same route. Rats were killed by decapitation at 0, 2, 4, 8, 16, 32, 64 and 72 hours after administr...

  9. Acetylcholinesterase-Inhibiting Activity of Pyrrole Derivatives from a Novel Marine Gliding Bacterium, Rapidithrix thailandica

    Sangnoi, Yutthapong; Sakulkeo, Oraphan; Yuenyongsawad, Supreeya; Kanjana-opas, Akkharawit; Ingkaninan, Kornkanok; Plubrukarn, Anuchit; Suwanborirux, Khanit

    2008-01-01

    Acetylcholinesterase-inhibiting activity of marinoquinoline A (1), a new pyrroloquinoline from a novel species of a marine gliding bacterium Rapidithrix thailandica, was assessed (IC50 4.9 μM). Two related pyrrole derivatives, 3-(2′-aminophenyl)-pyrrole (3) and 2,2-dimethyl-pyrrolo-1,2-dihydroquinoline (4), were also isolated from two other strains of R. thailandica. The isolation of 3 from a natural source is reported here for the first time. Compound 4 was proposed to be an isolation artifa...

  10. Involvement of oxidative stress in the enhancement of acetylcholinesterase activity induced by amyloid beta-peptide

    de Melo, Joana Barbosa; Agostinho, Paula; Oliveira, Catarina Resende

    2003-01-01

    Acetylcholinesterase (AChE) activity is increased within and around amyloid plaques, which are present in Alzheimer's disease (AD) patient's brain. In this study, using cultured retinal cells as a neuronal model, we analyzed the effect of the synthetic peptide A[beta]25-35 on the activity of AChE, the degradation enzyme of acetylcholine, as well as the involvement of oxidative stress in this process. The activity of AChE was increased when retinal cells were incubated with A[beta]25-35 (25 [m...

  11. Increases in muscle Ca2+ mediate changes in acetylcholinesterase and acetylcholine receptors caused by muscle contraction.

    Rubin, L L

    1985-01-01

    The synthesis of acetylcholinesterase (AcChoE; acetylcholine acetylhydrolase, EC 3.1.1.7) and of acetylcholine receptors (AcChoR) by cultured rat muscle fibers is influenced strongly by the level of muscle contractile activity. If fibers are grown in the presence of tetrodotoxin (TTX) to block spontaneous contraction, the total amount of AcChoE decreases markedly, as does the percentage of AcChoE assembled as the collagen-tailed presumed synaptic form of the enzyme. Under these conditions, ho...

  12. Synaptic and epidermal accumulations of human acetylcholinesterase are encoded by alternative 3'-terminal exons.

    Seidman, S; Sternfeld, M; Ben Aziz-Aloya, R; Timberg, R; Kaufer-Nachum, D; Soreq, H.

    1995-01-01

    Tissue-specific heterogeneity among mammalian acetylcholinesterases (AChE) has been associated with 3' alternative splicing of the primary AChE gene transcript. We have previously demonstrated that human AChE DNA encoding the brain and muscle AChE form and bearing the 3' exon E6 (ACHE-E6) induces accumulation of catalytically active AChE in myotomes and neuromuscular junctions (NMJs) of 2- and 3-day-old Xenopus embryos. Here, we explore the possibility that the 3'-terminal exons of two altern...

  13. MuSK is required for anchoring acetylcholinesterase at the neuromuscular junction

    Cartaud, Annie; Strochlic, Laure; Guerra, Manuel; Blanchard, Benoît; Lambergeon, Monique; Krejci, Eric; Cartaud, Jean; Legay, Claire

    2004-01-01

    At the neuromuscular junction, acetylcholinesterase (AChE) is mainly present as asymmetric forms in which tetramers of catalytic subunits are associated to a specific collagen, collagen Q (ColQ). The accumulation of the enzyme in the synaptic basal lamina strictly relies on ColQ. This has been shown to be mediated by interaction between ColQ and perlecan, which itself binds dystroglycan. Here, using transfected mutants of ColQ in a ColQ-deficient muscle cell line or COS-7 cells, we report tha...

  14. Soluble monomeric acetylcholinesterase from mouse: expression, purification, and crystallization in complex with fasciculin.

    Marchot, P.; Ravelli, R. B.; Raves, M. L.; Bourne, Y.; Vellom, D. C.; Kanter, J.; Camp, S; Sussman, J. L.; Taylor, P

    1996-01-01

    A soluble, monomeric form of acetylcholinesterase from mouse (mAChE), truncated at its carboxyl-terminal end, was generated from a cDNA encoding the glycophospholipid-linked form of the mouse enzyme by insertion of an early stop codon at position 549. Insertion of the cDNA behind a cytomegalovirus promoter and selection by aminoglycoside resistance in transfected HEK cells yielded clones secreting large quantities of mAChE into the medium. The enzyme sediments as a soluble monomer at 4.8 S. H...

  15. Presenilin 1 Interacts with Acetylcholinesterase and Alters Its Enzymatic Activity and Glycosylation▿

    Silveyra, María-Ximena; Evin, Geneviève; Montenegro, María-Fernanda; Vidal, Cecilio J; Martínez, Salvador; Culvenor, Janetta G.; Sáez-Valero, Javier

    2008-01-01

    Presenilin 1 (PS1) plays a critical role in the γ-secretase processing of the amyloid precursor protein to generate the β-amyloid peptide, which accumulates in plaques in the pathogenesis of Alzheimer's disease (AD). Mutations in PS1 cause early onset AD, and proteins that interact with PS1 are of major functional importance. We report here the coimmunoprecipitation of PS1 and acetylcholinesterase (AChE), an enzyme associated with amyloid plaques. Binding occurs through PS1 N-terminal fragmen...

  16. Isolation, Identification and Characterization of a Antidementia Acetylcholinesterase Inhibitor-Producing Yarrowia lipolytica S-3

    Kang, Min-Gu; Yoon, Min-Ho; Choi, Young-Jun; Lee, Jong-Soo

    2012-01-01

    This report describes the isolation and identification of a potent acetylcholinesterase (AChE) inhibitor-producing yeasts. Of 731 species of yeast strain, the S-3 strain was selected as a potent producer of AChE inhibitor. The selected S-3 strain was investigated for its microbiological characteristics. The S-3 strain was found to be short-oval yeast that did not form an ascospore. The strain formed a pseudomycelium and grew in yeast malt medium containing 50% glucose and 10% ethanol. Finally...

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

    Xiao Ding; Ming-An Ouyang; Xiang Liu; Rei-Zhen Wang

    2013-01-01

    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 ra...

  18. 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.

  19. Sesquiterpenes produced by endophytic fungus Phomopsis cassiae with antifungal and acetylcholinesterase inhibition activities

    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)

  20. 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.

  1. 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.

  2. 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. PMID:26489065

  3. 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.

  4. The effect of dichlorvos on acetylcholinesterase activity in some tissues in rats

    Dere E.

    2010-01-01

    Full Text Available In this study, the changes with respect to time in the serum, brain, liver, kidney and small intestine acetylcholinesterase activities were investigated in both male and female rats administered dichlorvos intraperitoneally (i.p.. For this purpose, 4 mg kg-1 doses of dichlorvos were injected i.p. in the rats. The control groups, on the other hand, were administered physiological saline via the same route. Rats were killed by decapitation at 0, 2, 4, 8, 16, 32, 64 and 72 hours after administration of dichlorvos and tissues were harvested. Enzyme activities were determined following the necessary treatments. While a significant decrease in enzyme activities in the kidney and small intestine tissues with respect to time were not observed in either sex, a significant decrease in enzyme activities in the serum, as well as in the brain and liver tissues were observed. As a result of our study, acetylcholinesterase activity was found to be decreased compared to controls in both male and female rats from 2 and 4 hours. Enzyme inhibition continued for up to 72 hours.

  5. 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.

  6. Selective radiolabeling and isolation of the hydrophobic membrane-binding domain of human erythrocyte acetylcholinesterase

    The hydrophobic, membrane-binding domain of purified human erythrocyte acetylcholinesterase was labeled with the photoactivated reagent 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine. The radiolabel was incorporated when the enzyme was prepared in detergent-free aggregates, in detergent micelles, or in phospholipid liposomes, but the highest percentage of labeling occurred in the detergent-free aggregates. Papain digestion of the enzyme released the hydrophobic domain, and polyacrylamide gel electrophoresis in sodium dodecyl sulfate or gel exclusion chromatography demonstrated that the label was localized exclusively in the cleaved hydrophobic domain fragment. This fragment was purified in a three-step procedure. Digestion was conducted with papain attached to Sepharose CL-4B, and the supernatant was adsorbed to acridinium affinity resin to remove the hydrophilic enzyme fragment. The nonretained fragment associated with Triton X-100 micelles was then chromatographed on Sepharose CL-6B, and finally detergent was removed by chromatography on Sephadex LH-60 in an ethanol-formic acid solvent. The fragment exhibited an apparent molecular weight of 3100 on the Sephadex LH-60 column when compared with peptide standards. However, amino acid analysis of the purified fragment revealed only 1 mol each of histidine and glycine per mole of fragment in contrast to the 25-30 mole of amino acids expected on the basis of the molecular weight estimate. This result suggests a novel non-amino acid structure for the hydrophobic domain of human erythrocyte acetylcholinesterase

  7. Wild Argentinian Amaryllidaceae, a New Renewable Source of the Acetylcholinesterase Inhibitor Galanthamine and Other Alkaloids

    Gabriela E. Feresin

    2012-11-01

    Full Text Available The Amaryllidaceae family is well known for its pharmacologically active alkaloids. An important approach to treat Alzheimer’s disease involves the inhibition of the enzyme acetylcholinesterase (AChE. Galanthamine, an Amaryllidaceae alkaloid, is an effective, selective, reversible, and competitive AchE inhibitor. This work was aimed at studying the alkaloid composition of four wild Argentinian Amarillydaceae species for the first time, as well as analyzing their inhibitory activity on acetylcholinesterase. Alkaloid content was characterized by means of GC-MS analysis. Chloroform basic extracts from Habranthus jamesonii, Phycella herbertiana, Rhodophiala mendocina and Zephyranthes filifolia collected in the Argentinian Andean region all contained galanthamine, and showed a strong AChE inhibitory activity (IC50 between 1.2 and 2 µg/mL. To our knowledge, no previous reports on alkaloid profiles and AChEIs activity of wild Argentinian Amarillydaceae species have been publisihed. The demand for renewable sources of industrial products like galanthamine and the need to protect plant biodiversity creates an opportunity for Argentinian farmers to produce such crops.

  8. Acetylcholinesterase is associated with a decrease in cell proliferation of hepatocellular carcinoma cells.

    Pérez-Aguilar, Benjamín; Vidal, Cecilio J; Palomec, Guillermina; García-Dolores, Fernando; Gutiérrez-Ruiz, María Concepción; Bucio, Leticia; Gómez-Olivares, José Luis; Gómez-Quiroz, Luis Enrique

    2015-07-01

    Acetylcholinesterase (AChE), the enzyme that rapidly splits acetylcholine into acetate and choline, presents non-cholinergic functions through which may participate in the control of cell proliferation and apoptosis. These two features are relevant in cancer, particularly in hepatocellular carcinoma (HCC), a very aggressive liver tumor with high incidence and poor prognosis in advanced stages. Here we explored the relation between acetylcholinesterase and HCC growth by testing the influence of AChE on proliferation of Huh-7 and HepG2 cell lines, addressed in monolayer cultures, spheroid formation and human liver tumor samples. Results showed a clear relation in AChE expression and cell cycle progression, an effect which depended on cell confluence. Inhibition of AChE activity led to an increase in cell proliferation, which was associated with downregulation of p27 and cyclins. The fact that Huh-7 and HepG2 cell lines provided similar results lent weight to the relationship of AChE expression with cell cycle progression in hepatoma cell lines at least. Human liver tumor samples exhibited a decrease in AChE activity as compared with normal tissue. The evidence presented herein provides additional support for the proposed tumor suppressor role of AChE, which makes it a potential therapeutic target in therapies against hepatocellular carcinoma. PMID:25869328

  9. Dietary supplementation with fermented legumes modulate hyperglycemia and acetylcholinesterase activities in Streptozotocin-induced diabetes.

    Ademiluyi, Adedayo O; Oboh, Ganiyu; Boligon, Aline A; Athayde, Margareth L

    2015-12-01

    The study investigated the hypoglycemic and anticholinesterase activities of some fermented legumes (bambara groundnut and locust bean) in Streptozotocin (STZ)-induced diabetic rats. The rats were made diabetic by intraperitoneal administration of STZ (35mg/kg b.w.) and were fed diets containing fermented legumes (10% inclusion) for 14 days. The effect of the diets on blood glucose, pancreatic glutathione peroxidase (GPx) activity, reduced glutathione (GSH) and malondialdehyde (MDA) contents, α-amylase, intestinal α-glucosidase and acetylcholinesterase activities were studied. Significant (Pglucose, pancreatic MDA, α-amylase, intestinal α-glucosidase and acetylcholinesterase activities with concomitant decrease in pancreatic GPx and GSH contents were observed in diabetic rats. However, this trend was reversed in rats fed fermented legumes supplemented diets for 14 days. The HPLC-DAD finger printing revealed the presence of gallic acid, catechin, caffeic acid, epicatechin, rutin, isoquercitrin, quercitrin, quercetin and kaempferol as the dominant phenolic compounds of the fermented legumes. However, possible contributing role of some bioactive peptides could not be ruled out. Hence, the hypoglycemic and antiacetylcholinesterase activities of the fermented legume condiments could be attributed to their constituent phytochemicals. PMID:26349771

  10. Selective radiolabeling and isolation of the hydrophobic membrane-binding domain of human erythrocyte acetylcholinesterase

    Roberts, W.L.; Rosenberry, T.L.

    1986-06-03

    The hydrophobic, membrane-binding domain of purified human erythrocyte acetylcholinesterase was labeled with the photoactivated reagent 3-(trifluoromethyl)-3-(m-(/sup 125/I)iodophenyl)diazirine. The radiolabel was incorporated when the enzyme was prepared in detergent-free aggregates, in detergent micelles, or in phospholipid liposomes, but the highest percentage of labeling occurred in the detergent-free aggregates. Papain digestion of the enzyme released the hydrophobic domain, and polyacrylamide gel electrophoresis in sodium dodecyl sulfate or gel exclusion chromatography demonstrated that the label was localized exclusively in the cleaved hydrophobic domain fragment. This fragment was purified in a three-step procedure. Digestion was conducted with papain attached to Sepharose CL-4B, and the supernatant was adsorbed to acridinium affinity resin to remove the hydrophilic enzyme fragment. The nonretained fragment associated with Triton X-100 micelles was then chromatographed on Sepharose CL-6B, and finally detergent was removed by chromatography on Sephadex LH-60 in an ethanol-formic acid solvent. The fragment exhibited an apparent molecular weight of 3100 on the Sephadex LH-60 column when compared with peptide standards. However, amino acid analysis of the purified fragment revealed only 1 mol each of histidine and glycine per mole of fragment in contrast to the 25-30 mole of amino acids expected on the basis of the molecular weight estimate. This result suggests a novel non-amino acid structure for the hydrophobic domain of human erythrocyte acetylcholinesterase.

  11. 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)

  12. Post-irradiation changes in acetylcholinesterase and butyrylcholinesterase activity in blood platelets of whole-body irradiated rats

    After 24, 96 and 144 hours following whole-body irradiation of rats with 8 Gy an increased acetylcholinesterase activity was found in platelets. The activity of butyrylcholinesterase in platelets increased in all investigated intervals after whole-body irradiation of rats with 8 Gy. The highest values were recorded after 144, 192 and 264 hours. (author)

  13. Effects of hunger level and nutrient balance on survival and acetylcholinesterase activity of dimethoate exposed wolf spiders

    Pedersen, Lars-Flemming; Dall, Lars G.; Sorensen, Bo C.; Mayntz, David; Toft, Soren

    2002-01-01

    were created by feeding them fruit flies of either high or low nutrient content for 28 days. Both groups were then split into satiated and 14 days starved subgroups. Each of these was further divided into insecticide treated and control halves. Survivorship and acetylcholinesterase (AChE) activity...

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

    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)

  15. 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

  16. Use of cytectrene marked by the technetium 99 to study the activity of Acetylcholinesterase in the rat brain

    Alzheimer's disease is a degenerative neurological disorder that causes progressive and irreversible loss of mental functions. It is the most common form of dementia and is characterized by a decrease in serotonergic neurons that carry the 5HT1A receptors. Derivatives piperidine with a tertiary amine and ester are similar to acetylcholine [natural substrate of acetylcholinesterase)], we used the cytectrene [molecule based piperidine marked the technetium 99m] as a substrate to investigate the activity of Acetylcholinesterase in the brain. The use of cytectrene for the quantitative measurement of the activity of the Acetylcholinesterase in the brain depends on the rate of hydrolysis and the enzymatic specificity. The results showed that the cytectrene can be used as a substrate for a precise and quantitative determination of the activity of this enzyme. The use of cytectrene as a substrate of Acetylcholinesterase and determination of its activity can use this molecule as an agent for early diagnosis of Alzheimer's disease. The results will, therefore, not only their importance on a fundamental level but also on a plan applied in the medical field. (Author)

  17. 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.…

  18. Antidotal effects of varthemia persica DC extract in organophosphate poisoning or warfare agents by measuring whole blood acetylcholinesterase

    The organophosphates (ORPs) or war fare agents toxicity results from inhibition of acetylcholinesterase (AchE). phosphylation of the active serin of AchE leads to accumulation of acetylcholine in synaptic clefts leading to generalized cholinergic over-stimulation. Standard treatment of ORP poisoning includes a muscarinic antagonist such as Atropine, and acetylcholinesterase reactivator (oxime). Presently, oximes like abidoxime and pralidoxime are approved as antidotes against ORP poisoning but are considered to be rather ineffective against certain ORP. Like Soman. In this study, the protective effect of Varthemia persica DC extract on acetylcholinesterase was examined in rats. Animals in weight range of 200-225 g were divided in 8 groups. The negative control group received only 0.4 ml normal saline, reference group, received ethylparaoxone in dose of 50 percent of LD50, positive control group, received ethylparaoxone (50% LD50) and one minute later 50 mol of pralidoxime. Test group 1: received ethylparaoxone and one minute later single dose of methanolic extract of Varthemia persica (250 mg/kg), Test Group 2: daily received methanolic extract of V.persica (250 mg/kg) in six days and one minute after last dose of extract, ethylparaoxone (50% LD50) were injected, Test Group 3: received ethylparaoxone (50% LD50) and then six doses of methanolic extract of V.persica (250 mg/kg) in six continuous days. Test Group 4: received ethylparaoxone and then single dose of dichloromethane extract of V.persica (250 mg/kg). Test Group 5: received ethylparaoxone and one minute later single high dose of methanolic extract of V.persica (1000 mg/kg). Then blood withdrawn and acetylcholinesterase activity was measured according to modified Ellman's method. Only in groups which received extract of V. persica before and after injection of ethylparaoxone, the mean of acetylcholinesterase activity was significantly different with reference group (p 0.05) but no significant difference with

  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. The herbicide glyphosate is a weak inhibitor of acetylcholinesterase in rats.

    Larsen, Karen E; Lifschitz, Adrián L; Lanusse, Carlos E; Virkel, Guillermo L

    2016-07-01

    The current work evaluated the inhibitory potency of the herbicide glyphosate (GLP) on acetylcholinesterase (AChE) activity in male and female rat tissues. The AChE activity in brain was higher (p<0.05) than those observed in kidney (females: 2.2-fold; males: 1.9-fold), liver (females: 6-fold; males: 6.9-fold) and plasma (females: 14.7-fold; males: 25.3-fold). Enzyme activities were higher in presence of 10mM GLP compared to those measured at an equimolar concentration of the potent AChE inhibitor dichlorvos (DDVP). Moreover, IC50s for GLP resulted between 6×10(4)- and 6.8×10(5)-fold higher than those observed for DDVP. In conclusion, GLP is a weak inhibitor of AChE in rats. PMID:27258137

  1. 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.

  2. Altered expression of acetylcholinesterase gene in rice results in enhancement or suppression of shoot gravitropism.

    Yamamoto, Kosuke; Sakamoto, Hikaru; Momonoki, Yoshie S

    2016-04-01

    Acetylcholinesterase (AChE), an acetylcholine-hydrolyzing enzyme, exists widely in plants, although its role in plant signal transduction is still unclear. We have hypothesized that the plant AChE regulates asymmetric distribution of hormones and substrates due to gravity stimulus, based on indirect pharmacological experiments using an AChE inhibitor. As a direct evidence for this hypothesis, our recent study has shown that AChE overexpression causes an enhanced gravitropic response in rice seedlings and suggested that the function of the rice AChE relates to the promotion of shoot gravitropism in the seedlings. Here, we report that AChE suppression inhibited shoot gravitropism in rice seedlings, as supportive evidence demonstrating the role of AChE as a positive regulator of shoot gravitropic response in plants. PMID:26979939

  3. High-sensitivity pesticide detection via silicon nanowires-supported acetylcholinesterase-based electrochemical sensors

    Su, Shao; He, Yao; Zhang, Mingliang; Yang, Kun; Song, Shiping; Zhang, Xiaohong; Fan, Chunhai; Lee, Shuit-Tong

    2008-07-01

    We report the use of a silicon-based nanocomplex, i.e., gold nanoparticles-coated silicon nanowires, for the improvement of acetylcholinesterase (AChE)-based electrochemical sensors for pesticide detection. Owing to the high electrical conductivity of the nanocomplex and its compatibility with the enzyme, the sensor exhibited significantly enhanced performance. The AChE enzyme bound to the surface possessed Michaelis-Menton constant of 81μM, resembling that in its free form. The sensor showed rapid response toward substrate acetylcholine in the concentration range of 1.0μM-1.0mM. This AChE nanosensor could detect as low as 8ng/L dichlorvos, an organophosphate pesticide.

  4. 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).

  5. Catalytic recruitment in the inactivation of acetylcholinesterase by soman: temperature dependence of the solvent isotope effect

    3,3-Dimethyl-2-butyl methylphosphonofluoridate (soman) recruits at least 60-70% of the catalytic power of acetylcholinesterase during phosphonylation of the active-site serine, as compared with the acetylation by acetylcholine. The solvent isotope effect is 1.34 +/- 0.11 and is temperature independent within experimental error between 5 and 450C. This observation is quite similar to what has been found for the reactions of aryl acetates and anilides. Average activation parameters for the same temperature range are ΔH* = 7.3 +/- 0.6 kcal/mol and ΔS* = -4 +/- 2 eu (H2O) and ΔH* = 7.1 +/- 0.4 kcal/mol and ΔS* = -6 +/- 1 eu (D2O). A rate-limiting process with 50% contribution of an induced-fit conformational change is supported by the data

  6. A radiotracer for In vivo studies of acetylcholinesterase: p-[18F]fluorodonepezil

    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-[18F]fluorodonepezil in mice. Biodistribution studies demonstrated that p-[18F]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

  7. 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.

  8. 1H NMR Relaxation Investigation of Inhibitors Interacting with Torpedo californica Acetylcholinesterase

    Delfini, Maurizio; Gianferri, Raffaella; Dubbini, Veronica; Manetti, Cesare; Gaggelli, Elena; Valensin, Gianni

    2000-05-01

    Two naphthyridines interacting with Torpedo californica acetylcholinesterase (AChE) were investigated. 1H NMR spectra were recorded and nonselective, selective, and double-selective spin-lattice relaxation rates were measured. The enhancement of selective relaxation rates could be titrated by different ligand concentrations at constant AChE (yielding 0.22 and 1.53 mM for the dissociation constants) and was providing evidence of a diverse mode of interaction. The double-selective relaxation rates were used to evaluate the motional correlation times of bound ligands at 34.9 and 36.5 ns at 300 K. Selective relaxation rates of bound inhibitors could be interpreted also in terms of dipole-dipole interactions with protons in the enzyme active site.

  9. Computational studies of acetylcholinesterase complexed with fullerene derivatives: a new insight for Alzheimer disease treatment.

    da Silva Gonçalves, Arlan; França, Tanos Celmar Costa; Vital de Oliveira, Osmair

    2016-06-01

    Here, we propose five fullerene (C60) derivatives as new drugs against Alzheimer's disease (AD). These compounds were designed to act as new human acetylcholinesterase (HssAChE) inhibitors by blocking its fasciculin II (FASII) binding site. Docking and molecular dynamic results show that our proposals bind to the HssAChE tunnel entrance, forming stable complex, and further binding free energy calculations suggest that three of the derivatives proposed here could be potent HssAChE inhibitors. We found a region formed by a set of residues (Tyr72, Asp74, Trp286, Gln291, Tyr341, and Pro344) which can be further exploited in the drug design of new inhibitors of HssAChE based on C60 derivatives. Results presented here report for the first time by a new class of molecules that can become effective drugs against AD. PMID:26219766

  10. Molecular interaction of acetylcholinesterase with carnosic acid derivatives: a neuroinformatics study.

    Merad, M; Soufi, W; Ghalem, S; Boukli, F; Baig, M H; Ahmad, K; Kamal, Mohammad A

    2014-04-01

    Alzheimer's disease is a progressive degenerative disease of the brain marked by gradual and irreversible declines in cognitive functions. Acetylcholinesterase (AChE) plays a biological role in the termination of nerve impulse transmissions at cholinergic synapses by rapid hydrolysis of its substrate, "acetylcholine". The deficit level of acetylcholine leads to deprived nerve impulse transmission. Thus the cholinesterase inhibitors would reverse the deficit in acetylcholine level and consequently may reverse the memory impairments, which is characteristic of the Alzheimer's disease. The molecular interactions between AChE and Carnosic acid, a well known antioxidant substance found in the leaves of the rosemary plant has always been an area of interest. Here in this study we have performed in silico approach to identify carnosic acid derivatives having the potential of being a possible drug candidate against AChE. The best candidates were selected on the basis of the results of different scoring functions. PMID:24059305

  11. 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.

  12. False positive gel-acetylcholinesterase results in blood-stained amniotic fluids.

    Barlow, R D; Cuckle, H S; Wald, N J; Rodeck, C H

    1982-10-01

    The effect of blood contamination on the gel-acetylcholinesterase (AChE) test used in the diagnosis of fetal open neural-tube defects was studied with amniotic fluid samples artificially contaminated with fetal or maternal blood in concentrations covering a range exceeding that usually found in clinical practice. Amniotic fluid samples contaminated with maternal blood gave negative gel-AChE results at all concentrations. Contamination with fetal blood yielded positive results if the erythrocyte concentration was greater than about 60 x 10(6) cells/ml. Thus contamination of amniotic fluid with blood is only likely to cause false positive gel-AChE results if this critical concentration is exceeded. Such samples will occur only rarely in clinical practice but when they do the diagnosis should be made with caution. PMID:7126503

  13. Detection of Carbofuran with Immobilized Acetylcholinesterase Based on Carbon Nano tubes-Chitosan Modified Electrode

    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 10-10  g/L to 10-3 g/L with a detection limit of 10-12 g/L. This biosensor is a promising new method for pesticide analysis

  14. The inhibition activity of selected beta-carboline alkaloids on enzymes of acetylcholinesterase and butyrylcholinesterase.

    Krsková, Zuzana; Martin, Jan; Dusek, Jaroslav

    2011-06-01

    This thesis deals with testing of inhibition activity beta-carboline alkaloids on activity of enzymes acetylcholinesterase (ACHE) and butyrylcholinesterase (BUCHE) using test "Fast Blue B salt" at TLC desk and Ellman's test using spectrophotometer. It was also investigated how dimethylsulfoxide used as a solvent in combination with water affects activity of enzymes and alkaloids. Results show harmine in form of base and salt in water and in mixture of DMSO and water has the hightest inhibition activity on ACHE using eserine as reference substance. Harmalol in form of salt in water and harmine in form of base and salt in mixture of DMSO and water has the hightest activity on BUCHE. It was find out that DMSO considerably affects activity of enzymes and alkaloids. PMID:21838142

  15. Effects of endosulfan on brain acetylcholinesterase activity in juvenile bluegill sunfish

    The effects of endosulfan upon brain acetylcholinesterase (AChE) activity were measured in juvenile blue gill sunfish (Lepomis macrochirus). Based on exposure durations of 0, 24, 48, 72, and 96 h and 1 week at 1.0 μg/L (just below the LC50 of 1.2 μg/L for this species), step-wise decreases in AChE activity were noted, corresponding to 0%, 3.57%, 12.65%, 14.23%, 16.31%, and 3.11% inhibition, respectively. Total brain protein concentrations were measured to test the accuracy of the Ache data with no significant anomalies. The duration of exposure was related to the reduction in the AChE activities which reflected the biotoxicity of endosulfan. The changes in the AChE activities will certainly affect the normal behavior of the juvenile blue gill which is detrimental to their very existence in the natural habitat

  16. Evaluation of acetylcholinesterase source from fish, Tor tambroides for detection of carbamate.

    Ahmad, Siti Aqlima; Sabullah, Mohd Khalizan; Shamaan, Nor Aripin; Abd Shukor, Mohd Yunus; Jirangon, Hussain; Khalid, Ariff; Syed, Mohd Arif

    2016-07-01

    Acetylcholinesterase (AChE) from the brain tissue of local freshwater fish, Tor tambroides was isolated through affinity purification. Acetylthiocholine iodide (ATCi) was preferable synthetic substrate to purified AChE with highest maximal velocity (V(max)) and lowest biomolecular constant (K(m)) at 113.60 Umg(-1) and 0.0689 mM, respectively, with highest catalytic efficiency ratio (V(max)/K(m)) of 1648.77. The optimum pH was 7.5 with sodium phosphate buffer as medium, while optimal temperature was in the range of 25 to 35 degrees C. Bendiocarp, carbofuran, carbaryl, methomyl and propoxur significantly lowered the AChE activity greater than 50%, and the IC50 value was estimated at inhibitor concentration of 0.0758, 0.0643, 0.0555, 0.0817 and 0.0538 ppm, respectively. PMID:27498490

  17. Acetylcholinesterase inhibition and altered locomotor behavior in the carabid beetle pterostichus

    Jensen, Charlotte S.; Krause-Jensen, Lone; Baatrup, Erik

    1997-01-01

    The establishment of cause–effect relationships is fundamental for the interpretation and the predictive value of biomarker responses measured at all levels of biological complexity. In the present study, the biochemical exposure biomarker acetylcholinesterase (AChE) inhibition was related to...... locomotor behavior, representing a general effect biomarker at the organismal level. Both sexes of the carabid beetle Pterostichus cupreus were intoxicated with three doses of the organophosphorous insecticide dimethoate. Five elements of their locomotor behavior were measured for 4 h employing computer......-aided video tracking, whereupon the whole body AChE activity was measured in the individual beetle. AChE inhibition was strongly correlated with dimethoate dose in both sexes. Alterations in the locomotor behavior were directly correlated with AChE inhibition in male beetles, which responded by reducing the...

  18. 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.

  19. Acetylcholinesterase-catalyzed acetate - water oxygen exchange studied by 13C-NMR

    The kinetics of the oxygen exchange reaction between [l-13C,18O2]acetate and H216O catalyzed by homogeneous acetyl-cholinesterase from the electric eel, Electrophorus electricus, was studied using the 18O-isotope-induced shift on 13C-nuclear magnetic resonance spectra. Pseudo-first-order rate constants for the exchange reactions were determined at pH values from 4.5 to 8. The exchange reaction exhibits a maximum at pH 5.8. The apparent catalytic rate constant for the exchange reaction is 102 to 104 times smaller than that for the deacylation of the acetyl-enzyme intermediate over the pH range tested. Oxygen exchange occurs by a random sequential pathway rather than by multiple (coupled) exchange. The inhibition of acetylcholinesterase by sodium acetate showed a sigmoidal dependence on pH, with K/sub i/ increasing 2.5 orders of magnitude over the pH range. Protonation of an active site residue having an apparent pKa of 6.8 is associated with an increase in acetate binding. Deacylation also exhibits a sigmoidal dependence on [H+]. The experimental data fits titration curves with inflection points at 5.0 +/- 0.3 and 6.7 +/-0.1. Results support the role of histidine in acetylation of the active site serine, but the conjugate base of another active site residue with a pKa of 5.0 appears necessary for maximal catalytic activity in both the deacylation and exchange reactions

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

    Highlights: • We used an economical and effective method for surface modification. • Chitosan/PEO nanofibrous membranes were modified by air-DBD plasma. • The most NH3+ 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 NH3+ 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 NH3+ 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

  1. TMPyP4, a Stabilizer of Nucleic Acid Secondary Structure, Is a Novel Acetylcholinesterase Inhibitor.

    Nana Fujiwara

    Full Text Available The porphyrin compound, TMPyP4 (5,10,15,20-Tetrakis-(N-methyl-4-pyridylporphine, is widely used as a photosensitizer and a modulator of nucleic acid secondary structure stability. Our group recently showed in cultured cells and forebrain slice cultures that this compound can also down regulate expression of Tyrosine hydroxylase (Th, which encodes the rate-limiting enzyme in catecholamine biosynthesis, by stabilizing DNA secondary structures in the Th proximal promoter. The current study sought to establish whether treatment with TMPyP4 could modify mouse Th expression levels in vivo. Intraperitoneal administration of low TMPyP4 doses (10mg/kg, similar to those used for photosensitization, did not significantly reduce Th transcript levels in several catecholaminergic regions. Administration of a high dose (40 mg/kg, similar to those used for tumor xenograph reduction, unexpectedly induced flaccid paralysis in an age and sex-dependent manner. In vitro analyses revealed that TMPyP4, but not putative metabolites, inhibited Acetylcholinesterase activity and pre-treatment of TMPyP4 with Hemeoxygenase-2 (HO-2 rescued Acetylcholinesterase function. Age-dependent differences in HO-2 expression levels may account for some of the variable in vivo effects of high TMPyP4 doses. Together, these studies indicate that only low doses of TMPyP4, such as those typically used for photosensitization, are well tolerated in vivo. Thus, despite its widespread use in vitro, TMPyP4 is not ideal for modifying neuronal gene expression in vivo by manipulating nucleic acid secondary structure stability, which highlights the need to identify more clinically suitable compounds that can modulate nucleic acid secondary structure and gene expression.

  2. Quantitation of megakaryocytopoiesis in liquid culture by enzymatic determination of acetylcholinesterase.

    Burstein, S A; Boyd, C N; Dale, G L

    1985-01-01

    A method has been developed to quantitate megakaryocytopoiesis in culture by measuring acetylcholinesterase synthesized in vitro. Murine marrow cells, treated with diisopropylfluorosphosphate (DFP) to inactivate initial acetylcholinesterase (AchE) present in megakaryocytes and contaminating blood, were set up in Iscove's medium supplemented with 15% DFP-treated horse serum +/- pokeweed mitogen-stimulated spleen cell conditioned medium (PWM-SCM) in 96-well microplates. Following the culture period, Triton X-100, dithiobisnitrobenzoic acid (DTNB), and acetylthiocholine iodide were added to each well. AchE synthesized in culture cleaved acetylthiocholine to thiocholine, which stochiometrically reduced the colorless indicator DTNB to a highly colored product. Thirty minutes following the addition of substrate, the plates were assayed for activity with a vertical recording photometer. When platelets, freshly prepared bone marrow cells, or cultured marrow were assayed by this method, a linear relationship was observed between optical density (OD) and the number of cells assayed. Moreover, a linear relationship between the number of AchE-positive megakaryocytes determined histochemically and AchE activity determined spectrophotometrically was observed. Red cells exhibited no activity. Inhibitor studies demonstrated that the activity measured was true AchE. Separation of marrow by density gradient centrifugation showed that the megakaryocyte enriched fraction contained all the AchE while the megakaryocyte depleted fraction contained none. From the data we conclude that this rapid, semiautomated method quantitates megakaryocytic AchE synthesis in culture, and that this method will be a useful assay system for the detection of factors that influence megakaryocytopoiesis. PMID:3965482

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

    GeraldineAWright

    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.

  4. 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.

  5. 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.

  6. Antioxidant and acetylcholinesterase-inhibitory properties of long-term stored medicinal plants

    Amoo Stephen O

    2012-07-01

    Full Text Available Abstract Background Medicinal plants are possible sources for future novel antioxidant compounds in food and pharmaceutical formulations. Recent attention on medicinal plants emanates from their long historical utilisation in folk medicine as well as their prophylactic properties. However, there is a dearth of scientific data on the efficacy and stability of the bioactive chemical constituents in medicinal plants after prolonged storage. This is a frequent problem in African Traditional Medicine. Methods The phytochemical, antioxidant and acetylcholinesterase-inhibitory properties of 21 medicinal plants were evaluated after long-term storage of 12 or 16 years using standard in vitro methods in comparison to freshly harvested materials. Results The total phenolic content of Artemisia afra, Clausena anisata, Cussonia spicata, Leonotis intermedia and Spirostachys africana were significantly higher in stored compared to fresh materials. The flavonoid content were also significantly higher in stored A. afra, C. anisata, C. spicata, L. intermedia, Olea europea and Tetradenia riparia materials. With the exception of Ekebergia capensis and L. intermedia, there were no significant differences between the antioxidant activities of stored and fresh plant materials as measured in the β-carotene-linoleic acid model system. Similarly, the EC50 values based on the 2,2-diphenyl-1-picrylhydrazyl (DPPH free radical scavenging assay were generally lower for stored than fresh material. Percentage inhibition of acetylcholinesterase was generally similar for both stored and fresh plant material. Stored plant material of Tetradenia riparia and Trichilia dregeana exhibited significantly higher AChE inhibition than the fresh material. Conclusions The current study presents evidence that medicinal plants can retain their biological activity after prolonged storage under dark conditions at room temperature. The high antioxidant activities of stable bioactive compounds in

  7. Acetylcholinesterase inhibitors and memantine for neuroenhancement in healthy individuals: a systematic review.

    Repantis, Dimitris; Laisney, Oona; Heuser, Isabella

    2010-06-01

    The term neuroenhancement refers to improvement in the cognitive, emotional and motivational functions of healthy individuals through, inter alia, the use of drugs. Of known interventions, psychopharmacology provides readily available options, such as the anti-dementia drugs, e.g. acetylcholinesterase inhibitors (donepezil, galantamine, rivastigmine) and memantine. Based on a systematic review we found that expectations about the potential of these drugs exceed their actual effects, as has been demonstrated in randomised controlled trials. Both single and repeated dose trials were included in the systematic review, however repeated dose trials have only been conducted for donepezil. In six small trials lasting 14-42 days, the following results emerged: donepezil improved the retention of training on complex aviation tasks and verbal memory for semantically processed words. In one study episodic memory was improved, whereas in others it remained unaffected by donepezil. In a sleep deprivation trial, donepezil reduced the memory and attention deficits resulting from 24h of sleep deprivation. Two studies reported even transient negative effects. Regarding the safety profile of donepezil, these studies found that it was rather well tolerated. In any case, since large longitudinal studies are not available no conclusions can be drawn. Seven small studies about the effects of a single dose of memantine, and one study with a single dose of rivastigmine have been reported. Again, these studies are not adequate to answer our research question. If, as here and elsewhere suggested, the concept of pharmaceutical neuroenhancement is not to be rejected in principle, the decision of healthy individuals to take drugs for the purpose of neuroenhancement should be based on exhaustive information. At the moment, the research that would support or oppose the use of acetylcholinesterase inhibitors and memantine for neuroenhancement by healthy individuals has not yet been performed

  8. FOXO1 locus and acetylcholinesterase inhibitors in elderly patients with Alzheimer’s disease

    Paroni G

    2014-10-01

    Full Text Available Giulia Paroni,1 Davide Seripa,1 Andrea Fontana,2 Grazia D’Onofrio,1 Carolina Gravina,1 Maria Urbano,1 Leandro Cascavilla,2 Fabio Pellegrini,2,3 Antonio Greco,1 Alberto Pilotto1,4 1Gerontology and Geriatrics Research Laboratory, 2Unit of Biostatistics, 3Unit of Biostatistics, Fondazione Mario Negri Sud, Santa Maria Imbaro (CH, Italy; 4Geriatrics Unit, Azienda ULSS 16 Padova, San Antonio Hospital, Padova, ItalyObjective: Acetylcholinesterase inhibitors (AChEIs may reduce the oxidative stress in brain of Alzheimer’s disease (AD patients. Forkhead box O1 (FoxO1 protein has been reported as the link between oxidative stress and AD. We evaluated a potential association between FOXO1 gene locus and the response to AChEI treatment in patients with sporadic AD.Methods: In this prospective study, 109 Caucasian AD patients were treated with standard doses of donepezil, galantamine, or rivastigmine for 6 months. Functional and cognitive status were evaluated at baseline and after treatment. Response to therapy was defined according to the National Institute for Health and Clinical Excellence criteria. Genotype analyses, including the APOE polymorphism, were made in blinded fashion.Results: A significantly higher frequency of FOXO1 rs7981045 G/G genotype was observed in nonresponders compared with responders (17.14% versus 2.70%, P=0.010. Age, sex, and APOE-adjusted logistic regression analysis confirmed that patients with the G/G genotype had a significantly higher risk of poor response to AChEI treatment (odds ratio =10.310; 95% confidence interval, 1.510–70.362. Haplotype analysis revealed significant differences in haplotype frequency distribution between these groups.Conclusion: FOXO1 may influence the clinical response to AChEIs in AD patients. Keywords: forkhead box O1, acetylcholinesterase inhibitors, response to treatment

  9. 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...

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

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

    The aim of this study was to investigate structures and acetylcholinesterase inhibitory activities of lycopodane-type alkaloids isolated from an Icelandic collection of Lycopodium annotinum ssp. alpestre. Ten alkaloids were isolated, including annotinine, annotine, lycodoline, lycoposerramine M...... 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...... californica acetylcholinesterase provided rationale for low inhibitory activity of the isolated alkaloids as compared to huperzine A or B, which are potent acetylcholinesterase inhibitors belonging to the lycodine class. Based on the modelling studies the lycopodane-type alkaloids seem to fit well into the...

  11. Acetylcholinesterase (AChE) inhibition in striated and heart muscles by C-547 (a derivative of 6-methyluracil representing a new class of AChE inhibitors)

    Říčný, Jan; Nikolsky, E. E.; Vyskočil, František; Soukup, Tomáš

    2007. s. 46-46. [Myores Annual Congress /3./. 17.12.2007-20.12.2007, Venice] Institutional research plan: CEZ:AV0Z50110509 Keywords : spo2 * acetylcholinesterase inhibition * muscle * C-547 Subject RIV: FH - Neurology

  12. Effects of glycyl-L-glutamine in vitro on the molecular forms of acetylcholinesterase in the preganglionically denervated superior cervical ganglion of the cat.

    Koelle, G B; Massoulié, J; Eugène, D; Melone, M.A.

    1988-01-01

    Normal and preganglionically denervated cat superior cervical ganglia were sectioned and cultured for 24 or 48 hr, with or without preliminary inactivation of acetylcholinesterase, and in the presence or absence of 10(-5) M glycyl-L-glutamine. They were then homogenized, and the molecular forms of acetylcholinesterase were analyzed by sucrose gradient sedimentation. We observed an increased proportion of the globular monomeric G1 form, and to a lesser extent of the dimeric G2 and tetrameric m...

  13. 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.

  14. 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,; Lallement, Guy; Clarençon, Didier; Thiermann, Horst; Worek, Franz

    2009-01-01

    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...

  15. 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.

  16. Reaction dynamics and transition-state structures for acetylcholinesterase-catalyzed hydrolysis of aryl esters and anilides

    The acylation and deacylation stages of acetylcholinesterase-catalyzed hydrolysis of various aryl ester and anilide substrates were investigated. For the natural substrate of acetylcholinesterase (AChE), acetylcholine, diffusion or enzyme conformational processes limit the acylation rate. Several anilides and aryl esters have been synthesized and found to be substrates of AChE. The acylation and deacylation reactivities of o-nitroformanilide, p-methoxyphenyl formate and o-nitrophenyl acetate were characterized by measuring substrate secondary and solvent isotope effects and by determining pL(L = H,D)-rate profiles and Eyring plots. Substrate secondary deuterium kinetic isotope effects are consistent with decreasing nucleophilic interaction at the carbonyl carbon of the scissle bond of the substrate in the rate-determining transition state with increasing V/K. These results lend quantitative support to a model for acylation rate determination involving a virtual transition state that contains contributions from the transition states of sequential physical and chemical steps

  17. Acetylcholinesterase of Schistosoma mansoni--functional correlates. Contributed in honor of Professor Hans Neurath's 90th birthday.

    Arnon, R; Silman, I.; Tarrab-Hazdai, R

    1999-01-01

    Acetylcholinesterase (AChE) is an enzyme broadly distributed in many species, including parasites. It occurs in multiple molecular forms that differ in their quaternary structure and mode of anchoring to the cell surface. This review summarizes biochemical and immunological investigations carried out in our laboratories on AChE of the helmint, Schistosoma mansoni. AChE appears in S. mansoni in two principal molecular forms, both globular, with sedimentation coefficients of approximately 6.5 a...

  18. Determination of Parathion and Carbaryl Pesticides in Water and Food Samples Using a Self Assembled Monolayer/Acetylcholinesterase Electrochemical Biosensor

    Mauro Bertotti; Sergio A. S. Machado; Josiane Caetano; Pedrosa, Valber A.

    2008-01-01

    An acetylcholinesterase (AchE) based amperometric biosensor was developed by immobilisation of the enzyme onto a self assembled modified gold electrode. Cyclic voltammetric experiments performed with the SAM-AchE biosensor in phosphate buffer solutions (pH = 7.2) containing acetylthiocholine confirmed the formation of thiocholine and its electrochemical oxidation at Ep = 0.28 V vs Ag/AgCl. An indirect methodology involving the inhibition effect of parathion and carbaryl on the enzymatic react...

  19. Insights and Ideas Garnered from Marine Metabolites for Development of Dual-Function Acetylcholinesterase and Amyloid-β Aggregation Inhibitors

    Stoddard, Shana V.; Hamann, Mark T.; Wadkins, Randy M.

    2014-01-01

    Due to the diversity of biological activities that can be found in aquatic ecosystems, marine metabolites have been an active area of drug discovery for the last 30 years. Marine metabolites have been found to inhibit a number of enzymes important in the treatment of human disease. Here, we focus on marine metabolites that inhibit the enzyme acetylcholinesterase, which is the cellular target for treatment of early-stage Alzheimer’s disease. Currently, development of anticholinesterase drugs...

  20. Dynamique structurale de l'acetylcholinesterase et ses implications dans la conception de réactivateurs

    Santoni, Gianluca

    2015-01-01

    Acetylcholinesterase (AChE), one of nature fastest enzyme, is the target of multiple toxics,including organophosphate nerve agents (OP). In the first part of this thesis I present thestructure-based development of a new uncharged reactivator, which showed characteristicsbetter than any molecule commercially available to date. The molecule has been rationallydesigned to present both affinity to the inhibited enzyme and good reactivation capabilities.The interactions between the lead molecule K...

  1. In Vitro Ability of Currently Available Oximes to Reactivate Organophosphate Pesticide-Inhibited Human Acetylcholinesterase and Butyrylcholinesterase

    Kamil Musilek; Kamil Kuca; Daniel Jun; Lucie Musilova

    2011-01-01

    We have in vitro tested the ability of common, commercially available, cholinesterase reactivators (pralidoxime, obidoxime, methoxime, trimedoxime and HI-6) to reactivate human acetylcholinesterase (AChE), inhibited by five structurally different organophosphate pesticides and inhibitors (paraoxon, dichlorvos, DFP, leptophos-oxon and methamidophos). We also tested reactivation of human butyrylcholinesterase (BChE) with the aim of finding a potent oxime, suitable to serve as a “pseudocatalytic...

  2. Effect of Neemta 2100 toxicity on acetylcholinesterase and serum glutamate oxaloacetate transaminase enzymes in serum of fish, Oreochromis mossambicus

    Parveen, M.; Sharma, R.; Kumar, S.

    2004-01-01

    Acetylcholinesterase and serum glutamate oxaloacetate transaminase enzymes have been used as marker monitoring the effect of neem seed based pesticide Neemta 2100 on the fish, Oreochromis mossambicus. Fishes exposed to sublethal concentrations of Neemta 2100 for acute periods of 24 and 48 hours were sacrificed to determine enzyme activities in serum affected due to toxicity. Laboratory studies of in vivo exposure of this pesticide showed synergistic inhibitory effect during acute period of to...

  3. COMPARISON OF BIOCHEMICAL AND MOLECULAR TESTS FOR DETECTING INSECTICIDE RESISTANCE DUE TO INSENSITIVE ACETYLCHOLINESTERASE IN CULEX QUINQUEFASCIATUS1

    SCOTT, MARIAH L.; McALLISTER, JANET C.

    2012-01-01

    Insecticide resistance to organophosphates and carbamates can be the result of changes in acetylcholinesterase activity conferred by the ACE-1 mutation. Detection of this altered target site mutation is important in guiding informed decisions for resistance management. In this study we compared a competitive enzyme assay with a polymerase chain reaction assay utilizing a restriction enzyme. Both assays detected the ACE-1 mutation in Culex quinquefasciatus and agreement was 100%. The costs and...

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

    2014-01-01

    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...

  5. Detection of Anatoxin-a(s) in Environmental Samples of Cyanobacteria by Using a Biosensor with Engineered Acetylcholinesterases

    Devic, Eric; Li, Dunhai; Dauta, Alain; Henriksen, Peter; Codd, Geoffrey A.; Marty, Jean-Louis; Fournier, Didier

    2002-01-01

    Bioassays are little used to detect individual toxins in the environment because, compared to analytical methods, these assays are still limited by several problems, such as the sensitivity and specificity of detection. We tentatively solved these two drawbacks for detection of anatoxin-a(s) by engineering an acetylcholinesterase to increase its sensitivity and by using a combination of mutants to obtain increased analyte specificity. Anatoxin-a(s), a neurotoxin produced by some freshwater cy...

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

    Johannes Van Staden; Jeffrey F. Finnie; Ndhlala, Ashwell R.

    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...

  7. Cellular Localization of the Molecular Forms of Acetylcholinesterase in rat Pheochromocytoma Pc12 Cells Treated with Nerve Growth Factor1

    Inestrosa, Nibaldo C; Reiness, C. Gary; Reichardt, Louis F.; Hall, Zach W

    1981-01-01

    In rat pheochromocytoma (PC12) cells treated with nerve growth factor (NGF), there are several molecular forms of the enzyme acetylcholinesterase (AChE) which sediment on sucrose density gradients at 4 to 6, 10, and 16 S, respectively. We have investigated the cellular localization of these forms in PC12 cells. In order to determine which forms are soluble and which are membrane bound, we extracted PC12 cells in buffers of various ionic strengths and detergent compositions. To distinguish int...

  8. Limiting Role of Protein Disulfide Isomerase in the Expression of Collagen-tailed Acetylcholinesterase Forms in Muscle*

    Carlos A. Ruiz; Rotundo, Richard L.

    2009-01-01

    The expression of acetylcholinesterase (AChE) in skeletal muscle is regulated by muscle activity; however, the underlying molecular mechanisms are incompletely understood. We show here that the expression of the synaptic collagen-tailed AChE form (ColQ-AChE) in quail muscle cultures can be regulated by muscle activity post-translationally. Inhibition of thiol oxidoreductase activity decreases expression of all active AChE forms. Likewise, primary quail myotubes transfected with protein disulf...

  9. Acetylcholinesterase-positive afferent axons in mucosa of urinary bladder of adult cats: retrograde tracing and degeneration studies

    Wakabayashi, Y.; Kojima, Y.; Makiura, Y.; Tomoyoshi, T.; Maeda, T.

    1995-01-01

    Acetylcholinesterase (AchE)-positive afferent axons in the mucosa of the cat urinary bladder were examined in the present experiments. Smallsized dorsal root ganglion cells containing AchE enzyme activity were labelled by injection of retrograde tracer (wheat germ agglutinin conjugated to enzymatically inactive horseradish peroxidase gold complex) into the bladder mucosa of adult cats. Results show that 48.9% (901184) of the labelled ganglion cells possesse...

  10. Cloning of Two Acetylcholinesterase Genes and Analysis of Point Mutations Putatively Associated with Triazophos Resistance in Chilo auricilius (Lepidoptera: Pyralidae).

    Luo, Guang-Hua; Li, Xiao-Huan; Zhang, Zhi-Chun; Liu, Bao-Sheng; Huang, Shui-Jin; Fang, Ji-Chao

    2015-06-01

    Acetylcholinesterase (AChE) is the target of organophosphate (OP) and carbamate insecticides. Mutations in the AChE gene (ace) leading to decreased insecticide susceptibility is the main resistance mechanism in insects. In this study, two Chilo auricilius acetylcholinesterase genes, designated as Caace1 and Caace2, were cloned using RT-PCR and RACE. Caace1 cDNA is 2534 bp, with ORF of 2082 bp, and it encodes an acetylcholinesterase 1 (CaAChE1) protein comprising a calculated 693 amino acid (aa) residues. Caace2 cDNA contains 2280 bp, with a full-length ORF of 1917 bp, encoding acetylcholinesterase 2 (CaAChE2) comprising a calculated 638 aa residues. At the aa level, CaAChE1 displays the highest similarity (97%) with the Chilo suppressalis AChE1, and CaAChE2 shows the highest similarity with the C. suppressalis AChE2 (99%). From the restriction fragment length polymorphism (RFLP) PCR (RFLP-PCR) analysis, one mutation in Caace1, similar to the ace1 mutation associated with triazophos resistance in C. suppressalis, was detected. Detailed examination of field populations of C. auricilius indicated this resistance mutation in C. auricilius is still quite infrequent. Based on the assay of AChE activity and RFLP-PCR testing, an individual that contains resistance mutation has lower AChE activities, while the individual that does not contain the resistance mutation has higher AChE activities. This study provides a basis for future investigations into the mechanism of OP resistance in C. auricilius, as well as a guidance for C. auricilius control with reasonable choice of pesticides. PMID:26470257

  11. Effects of Androctonus crassicauda (Olivier, 1807) (scorpiones: buthidae) venom on rats: correlation among acetylcholinesterase activities and electrolytes levels

    O Ozkan; S. Adiguzel; Kar, S.; Kurt, M.; S. Yakistiran; Y Cesaretli; Orman, M; KARAER, Z.

    2007-01-01

    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 rec...

  12. An optimized extraction technique for acetylcholinesterase inhibitors from the Camellia japonica seed cake by using response surface methodology.

    Kim, Jae Kyeom; Kim, Cho Rong; Lim, Ho-Jeong; Nam, Sang Hae; Joo, Ok Soo; Shin, Dong-Hoon; Shin, Eui-Cheol

    2014-01-01

    The response surface methodology (RSM) was used to optimize the extraction conditions for the acetylcholinesterase (AchE) inhibitory activity and extraction yield from Camellia japonica seed cake. Predicted values for AchE inhibition and extraction yield were 19.41 and 13.35%, respectively, which are in good agreement with the experimental values from validation, suggesting that RSM may provide a useful tool to optimization processes. PMID:25229864

  13. 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, W.; 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 inhibitor sildenafil and AChE inhibitors metrifonate and donepezil in the object recognition task to find out whether acquisition or consolidation processes were affected by these drugs. Methods The objec...

  14. A Novel Application of Multiscale Entropy in Electroencephalography to Predict the Efficacy of Acetylcholinesterase Inhibitor in Alzheimer’s Disease

    Ping-Huang Tsai; Shih-Chieh Chang; Fang-Chun Liu; Jenho Tsao; Yung-Hung Wang; Men-Tzung Lo

    2015-01-01

    Alzheimer's disease (AD) is the most common form of dementia. According to one hypothesis, AD is caused by the reduced synthesis of the neurotransmitter acetylcholine. Therefore, acetylcholinesterase (AChE) inhibitors are considered to be an effective therapy. For clinicians, however, AChE inhibitors are not a predictable treatment for individual patients. We aimed to disclose the difference by biosignal processing. In this study, we used multiscale entropy (MSE) analysis, which can disclose ...

  15. Low 25OH vitamin D2 levels found in untreated Alzheimer's patients, compared to acetylcholinesterase-inhibitor treated and controls.

    Shah, Iltaf; Petroczi, Andrea; Tabet, Naji; Klugman, Anthony; Isaac, Mokhtar; Naughton, Declan P

    2012-11-01

    Following contradictory reports, the aim of this study was to apply our highly specific novel assay to delineate the relationship between vitamin D forms and Alzheimer's disease. The study incorporated patients, both untreated and treated with acetylcholinesterase inhibitors, along with controls. Patients were grouped as A: untreated (n=26) and B: treated with donepezil, rivastigmine or galantamine (n=44). The study included a control Group (C, n=35) with no cognitive impairment. Cognitive function was assessed using the MMSE. Levels of vitamin D forms were measured using liquid chromatography-mass spectrometry (LC-MS/MS) and calcium measurements were conducted using inductively coupled plasma-mass spectrometry (ICP-MS). In the cohort studied, no relationship was observed between MMSE score, calcium and any form of vitamin D. The indisputable finding is that the level of 25hydroxyvitamin D2 (25OHD2) (3.165 ± 6.352 nmol/L, p vitamin D2 and total vitamin D were the highest for the untreated group. Vitamin D levels, assessed as 25OHD are significantly lower in patients suffering from Alzheimer's disease arising from extremely low levels of 25OHD2 along with low levels of 25OHD3. Treatment with acetylcholinesterase inhibitors reverses this deficit. Further research is warranted to delineate the mode of action of acetylcholinesterase inhibitors with respect to normalising 25OHD2 levels. These observations resulted in the hypothesis that along with the common functions of vitamin D, different forms have distinct roles in health and disease. PMID:22876849

  16. 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.

  17. Inhibition of acetylcholinesterase by green and white tea and their simulated intestinal metabolites.

    Okello, Edward J; Leylabi, Ramin; McDougall, Gordon J

    2012-06-01

    By 2034 it is forecast that 5% of the global population will be aged 85 years or over--approximately two and half fold increase on present day figures--which will inevitably lead to an increase in age-associated disorders such as Alzheimer's disease. There is mounting evidence that green tea (Camellia sinensis) possesses numerous health-promoting properties, and may potentially be beneficial to those suffering from Alzheimer's and other diseases, including cardiovascular disease and cancer. These beneficial properties are largely attributed to the high polyphenol content, particularly the catechins. In this study, we measured acetylcholinesterase inhibition by white and green teas and their simulated intestinal digests. We found that the potency with which the white and green tea extracts inhibited acetylcholinesterase varied through the simulated digestion procedure. Initially, in the undigested extract form, potency was high with IC₅₀ values of 7.20 μg mL⁻¹ and 8.06 μg mL⁻¹ for green and white tea respectively.However, this decreased significantly after gastric digestion but activity was recovered after pancreatic digestion which could be related to relative increases in the levels of caffeine and specific phenolic components. Of the pure tea compounds tested, EGCG was the most potent with an IC₅₀ of 0.0096 μmol mL⁻¹ but its breakdown product; γ-valerolactone was the least potent analyte. Particularly interesting were the results of caffeine,which exhibited a strong inhibitory activity and pyrogallol, which recorded a much stronger potency than its parent compound gallic acid, suggesting a pro-drug-like relationship. Overall, the results indicate that further research is necessary to determine the full potential of digestion of tea and its metabolites and how inter-individual variation may indicate that some sections of society could potentially benefit more from drinking tea as a strategy to prevent the development of dementia. We have also

  18. Bioactive Paper Sensor Based on the Acetylcholinesterase for the Rapid Detection of Organophosphate and Carbamate Pesticides

    Mohamed E. I. Badawy

    2014-01-01

    Full Text Available In many countries, people are becoming more concerned about pesticide residues which are present in or on food and feed products. For this reason, several methods have been developed to monitor the pesticide residue levels in food samples. In this study, a bioactive paper-based sensor was developed for detection of acetylcholinesterase (AChE inhibitors including organophosphate and carbamate pesticides. Based on the Ellman colorimetric assay, the assay strip is composed of a paper support (1×10 cm, onto which a biopolymer chitosan gel immobilized in crosslinking by glutaraldehyde with AChE and 5,5′-dithiobis(2-nitrobenzoic acid (DTNB and uses acetylthiocholine iodide (ATChI as an outside reagent. The assay protocol involves introducing the sample to sensing zone via dipping of a pesticide-containing solution. Following an incubation period, the paper is placed into ATChI solution to initiate enzyme catalyzed hydrolysis of the substrate, causing a yellow color change. The absence or decrease of the yellow color indicates the levels of the AChE inhibitors. The biosensor is able to detect organophosphate and carbamate pesticides with good detection limits (methomyl=6.16×10-4 mM and profenofos=0.27 mM and rapid response times (~5 min. The results show that the paper-based biosensor is rapid, sensitive, inexpensive, portable, disposable, and easy-to-use.

  19. Acetylcholinesterase triggers the aggregation of PrP 106-126

    Acetylcholinesterase (AChE), a senile plaque component, promotes amyloid-β-protein (Aβ) fibril formation in vitro. The presence of prion protein (PrP) in Alzheimer's disease (AD) senile plaques prompted us to assess if AChE could trigger the PrP peptides aggregation as well. Consequently, the efficacy of AChE on the PrP peptide spanning-residues 106-126 aggregation containing a coumarin fluorescence probe (coumarin-PrP 106-126) was studied. Kinetics of coumarin-PrP 106-126 aggregation showed a significant increase of maximum size of aggregates (MSA), which was dependent on AChE concentration. AChE-PrP 106-126 aggregates showed the tinctorial and optical amyloid properties as determined by polarized light and electronic microscopy analysis. A remarkable inhibition of MSA was obtained with propidium iodide, suggesting that AChE triggers PrP 106-126 and Aβ aggregation through a similar mechanism. Huprines (AChE inhibitors) also significantly decreased MSA induced by AChE as well, unveiling the potential interest for some AChE inhibitors as a novel class of potential anti-prion drugs

  20. Cinnamomum loureirii Extract Inhibits Acetylcholinesterase Activity and Ameliorates Trimethyltin-Induced Cognitive Dysfunction in Mice.

    Kim, Cho Rong; Choi, Soo Jung; Kwon, Yoon Kyung; Kim, Jae Kyeom; Kim, Youn-Jung; Park, Gwi Gun; Shin, Dong-Hoon

    2016-01-01

    The pathogenesis of Alzheimer's disease (AD) has been linked to the deficiency of neurotransmitter acetylcholine (ACh) in the brain, and the main treatment strategy for improving AD symptoms is the inhibition of acetylcholinesterase (AChE) activity. In the present study, we aimed to identify potent AChE inhibitors from Cinnamomum loureirii extract via bioassay-guided fractionation. We demonstrated that the most potent AChE inhibitor present in the C. loureirii extract was 2,4-bis(1,1-dimethylethyl)phenol. To confirm the antiamnesic effects of the ethanol extract of C. loureirii, mice were intraperitoneally injected with the neurotoxin trimethyltin (2.5 mg/kg) to induce cognitive dysfunction, and performance in the Y-maze and passive avoidance tests was assessed. Treatment with C. loureirii extract significantly improved performance in both behavioral tests, suggesting that this extract may be neuroprotective and therefore beneficial in preventing or ameliorating the degenerative processes of AD, potentially by restoring cholinergic function. PMID:27374288

  1. Translational regulation of acetylcholinesterase by the RNA-binding protein Pumilio-2 at the neuromuscular synapse.

    Marrero, Emilio; Rossi, Susana G; Darr, Andrew; Tsoulfas, Pantelis; Rotundo, Richard L

    2011-10-21

    Acetylcholinesterase (AChE) is highly expressed at sites of nerve-muscle contact where it is regulated at both the transcriptional and post-transcriptional levels. Our understanding of the molecular mechanisms underlying its regulation is incomplete, but they appear to involve both translational and post-translational events as well. Here, we show that Pumilio-2 (PUM2), an RNA binding translational repressor, is highly localized at the neuromuscular junction where AChE mRNA concentrates. Immunoprecipitation of muscle cell extracts with a PUM2 specific antibody precipitated AChE mRNA, suggesting that PUM2 binds to the AChE transcripts in a complex. Gel shift assays using a bacterially expressed PUM2 RNA binding domain showed specific binding using wild type AChE 3'-UTR RNA segment that was abrogated by mutation of the consensus recognition site. Transfecting skeletal muscle cells with shRNAs specific for PUM2 up-regulated AChE expression, whereas overexpression of PUM2 decreased AChE activity. We conclude that PUM2 binds to AChE mRNA and regulates AChE expression translationally at the neuromuscular synapse. Finally, we found that PUM2 is regulated by the motor nerve suggesting a trans-synaptic mechanism for locally regulating translation of specific proteins involved in modulating synaptic transmission, analogous to CNS synapses. PMID:21865157

  2. Translational Regulation of Acetylcholinesterase by the RNA-binding Protein Pumilio-2 at the Neuromuscular Synapse*

    Marrero, Emilio; Rossi, Susana G.; Darr, Andrew; Tsoulfas, Pantelis; Rotundo, Richard L.

    2011-01-01

    Acetylcholinesterase (AChE) is highly expressed at sites of nerve-muscle contact where it is regulated at both the transcriptional and post-transcriptional levels. Our understanding of the molecular mechanisms underlying its regulation is incomplete, but they appear to involve both translational and post-translational events as well. Here, we show that Pumilio-2 (PUM2), an RNA binding translational repressor, is highly localized at the neuromuscular junction where AChE mRNA concentrates. Immunoprecipitation of muscle cell extracts with a PUM2 specific antibody precipitated AChE mRNA, suggesting that PUM2 binds to the AChE transcripts in a complex. Gel shift assays using a bacterially expressed PUM2 RNA binding domain showed specific binding using wild type AChE 3′-UTR RNA segment that was abrogated by mutation of the consensus recognition site. Transfecting skeletal muscle cells with shRNAs specific for PUM2 up-regulated AChE expression, whereas overexpression of PUM2 decreased AChE activity. We conclude that PUM2 binds to AChE mRNA and regulates AChE expression translationally at the neuromuscular synapse. Finally, we found that PUM2 is regulated by the motor nerve suggesting a trans-synaptic mechanism for locally regulating translation of specific proteins involved in modulating synaptic transmission, analogous to CNS synapses. PMID:21865157

  3. Effect of dichlorvos on the acetylcholinesterase from tambaqui (Colossoma macropomum) brain.

    Assis, Caio Rodrigo Dias; Amaral, Ian Porto Gurgel; Castro, Patrícia Fernandes; Carvalho, Luiz Bezerra Júnior; Bezerra, Ranilson Souza

    2007-07-01

    Dichlorvos is an acutely toxic organophosphorous pesticide that is known as a classical acetylcholinesterase (AChE; EC 3.1.1.7) inhibitor. Here, the brain AChE from the important Amazonian fish tambaqui (Colossoma macropomum) was assayed in the presence of this insecticide and also of deltamethrin, a classical sodium and potassium channel inhibitor (negative control). Four tissue homogenates were analyzed in triplicate for AChE activity using acetylthiocholine as the substrate and 5,5'-dithiobis(2-nitrobenzoic) acid (DTNB) as the color-developing agent. Each tissue homogenate represented pooled brains from five fish. The inhibitory effect of dichlorvos on AChE activities was determined at concentrations from 0.001 to 10 ppm and compared to controls. This effect followed an exponential decay model (y = 9.420 + 26.192e(-x/5.380); r2 = 0.989), presenting IC50 (the concentration of dichlorvos that is required for 50% of AChE inhibition) of 0.081 ppm (0.368 micromol/L). No effect was observed for the deltamethrin, and the concentration 0.0452 micromol/L of dichlorvos was significantly different from this control. These results suggest that tambaqui brain AChE can be proposed as a biomarker for dichlorvos and can be used as a tool for aquatic environment monitoring. PMID:17665685

  4. 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.

  5. 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.

  6. A sensitive acetylcholinesterase biosensor based on gold nanorods modified electrode for detection of organophosphate pesticide.

    Lang, Qiaolin; Han, Lei; Hou, Chuantao; Wang, Fei; Liu, Aihua

    2016-08-15

    A sensitive amperometric acetylcholinesterase (AChE) biosensor, based on gold nanorods (AuNRs), was developed for the detection of organophosphate pesticide. Compared with Au@Ag heterogeneous NRs, AuNRs exhibited excellent electrocatalytic properties, which can electrocatalytically oxidize thiocholine, the hydrolysate of acetylthiocholine chloride (ATCl) by AChE at +0.55V (vs. SCE). The AChE/AuNRs/GCE biosensor was fabricated on basis of the inhibition of AChE activity by organophosphate pesticide. The biosensor could detect paraoxon in the linear range from 1nM to 5μM and dimethoate in the linear range from 5nM to 1μM, respectively. The detection limits of paraoxon and dimethoate were 0.7nM and 3.9nM, which were lower than the reported AChE biosensor. The proposed biosensor could restore to over 95% of its original current, which demonstrated the good reactivation. Moreover, the biosensor can be applicable to real water sample measurement. Thus, the biosensor exhibited low applied potential, high sensitivity and good stability, providing a promising tool for analysis of pesticides. PMID:27260432

  7. 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.

  8. 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. PMID:25973480

  9. Nanoparticle-based immunosensor with apoferritin templated metallic phosphate label for quantification of phosphorylated acetylcholinesterase

    Du, Dan; Chen, Aiqiong; Xie, Yunying; Zhang, Aidong; Lin, Yuehe

    2011-05-15

    A new sandwich-like electrochemical immunosensor has been developed for quantification of organophosphorylated acetylcholinesterase (OP-AChE), an exposure biomarker of organophosphate pesticides and nerve agents. Zirconia nanoparticles (ZrO2 NPs) were anchored on a screen printed electrode (SPE) to preferably capture OP-AChE adducts by metal chelation with phospho-moieties, which was selectively recognized by lead phosphate-apoferritin labeled anti-AChE antibody (LPA-anti-AChE). The sandwich-like immunoreactions were performed among ZrO2 NPs, OP-AChE and LPA-anti-AChE to form ZrO2/OP-AChE/LPA-anti-AChE complex and the released lead ions were detected on a disposable SPE. The binding affinity was investigated by both square wave voltammetry (SWV) and quartz crystal microbalance (QCM) measurements. The proposed immunosensor yielded a linear response current over a broad OP-AChE concentrations range from 0.05 nM to 10 nM, with detection limit of 0.02 nM, which has enough sensitivity for monitoring of low-dose exposure to OPs. This method avoids the drawback of unavailability of commercial OP-specific antibody as well as amplifies detection signal by using apoferritin encoded metallic phosphate nanoparticle tags. This nanoparticle-based immunosensor offers a new method for rapid, sensitive, selective and inexpensive quantification of phosphorylated adducts for monitoring of OP pesticides and nerve agents exposures.

  10. Novel Selective and Irreversible Mosquito Acetylcholinesterase Inhibitors for Controlling Malaria and Other Mosquito-Borne Diseases

    Dou, Dengfeng; Park, Jewn Giew; Rana, Sandeep; Madden, Benjamin J.; Jiang, Haobo; Pang, Yuan-Ping

    2013-01-01

    We reported previously that insect acetylcholinesterases (AChEs) could be selectively and irreversibly inhibited by methanethiosulfonates presumably through conjugation to an insect-specific cysteine in these enzymes. However, no direct proof for the conjugation has been published to date, and doubts remain about whether such cysteine-targeting inhibitors have desirable kinetic properties for insecticide use. Here we report mass spectrometric proof of the conjugation and new chemicals that irreversibly inhibited African malaria mosquito AChE with bimolecular inhibition rate constants (kinact/KI) of 3,604-458,597 M-1sec-1 but spared human AChE. In comparison, the insecticide paraoxon irreversibly inhibited mosquito and human AChEs with kinact/KI values of 1,915 and 1,507 M-1sec-1, respectively, under the same assay conditions. These results further support our hypothesis that the insect-specific AChE cysteine is a unique and unexplored target to develop new insecticides with reduced insecticide resistance and low toxicity to mammals, fish, and birds for the control of mosquito-borne diseases.

  11. 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.

  12. Syntheses of carbon-11 labeled piperidine esters as potential in vivo substrates for acetylcholinesterase

    A series of carbon-11 labeled N-methylpiperidinyl esters were prepared as potential in vivo substrates for acetylcholinesterase (AChE). Target compounds were designed based on the structure of N-[11C]methylpiperidin-4-yl propionate, an ester currently used to measure AChE enzymatic activity in the human brain, to examine the structure-activity relationship for in vivo enzymatic hydrolysis. Changes in steric bulk and in the ester order ('reverse' esters) were made. Addition of methyl groups was made to both the acid side chain (synthesis of N-[11C]methylmethylpiperidin-4-yl isobutyrate) and to the piperidine ring (syntheses of N-[11C]methyl-4-methylpiperidin-4-yl propionate, N-[11C]methyl-4-methylpiperidin-4-yl acetate, and N-[11C]methyl-3-methylpiperidin-4-yl propionate). Alterations of the order of the ester heteroatoms was accomplished through syntheses of the N-[11C]methyl-2,3- and 4-piperidinecarboxylic acid ethyl esters. Finally, an additional piperidine-based ester (N-[11C]methylpiperidin-2-yl)methyl propionate was also prepared. All carbon-11-labeled esters were prepared by N-[11C]methylation reactions, using the desmethyl precursors and no-carrier-added [11C]methyltriflate, and were obtained in decay-corrected yields (not optimized) of 10-40% and high specific activities

  13. Blocked Enzymatic Etching of Gold Nanorods: Application to Colorimetric Detection of Acetylcholinesterase Activity and Its Inhibitors.

    Saa, Laura; Grinyte, Ruta; Sánchez-Iglesias, Ana; Liz-Marzán, Luis M; Pavlov, Valeri

    2016-05-01

    The anisotropic morphology of gold nanorods (AuNRs) has been shown to lead to nonuniform ligand distribution and preferential etching through their tips. We have recently demonstrated that this effect can be achieved by biocatalytic oxidation with hydrogen peroxide, catalyzed by the enzyme horseradish peroxidase (HRP). We report here that modification of AuNRs with thiol-containing organic molecules such as glutathione and thiocholine hinders enzymatic AuNR etching. Higher concentrations of thiol-containing molecules in the reaction mixture gradually decrease the rate of enzymatic etching, which can be monitored by UV-vis spectroscopy through changes in the AuNR longitudinal plasmon band. This effect can be applied to develop novel optical assays for acetylcholinesterase (AChE) activity. The biocatalytic hydrolysis of acetylthiocholine by AChE yields thiocholine, which prevents enzymatic AuNR etching in the presence of HRP. Additionally, the same bioassay can be used for the detection of nanomolar concentrations of AChE inhibitors such as paraoxon and galanthamine. PMID:27070402

  14. The Influence of Malathion and Its Decomposition Products on Free and Immobilized Acetylcholinesterase1

    Krstić, D.; Çolović, M.; Kralj, M. B.; Trebše, P.; Krinulović, K.; Vasić, V.

    2008-04-01

    The influence of malathion and its four main degradation products found in irradiated solutions (malaoxon, isomalathion, diethyl maleate and O,O-dimethyl phosphate) on acetylcholinesterase (AChE) of free and immobilized bovine erythrocytes was investigated. The concentration-dependent responses to malathion and related organophosphates, malaoxon and isomalathion, of both AChE bioassays used were obtained. The IC 50 values for free and immobilized AChE (3.7 ± 0.2) × 10-4 M/(1.6 ± 0.1) × 10-4, (2.4 ± 0.3) × 10-6/(3.4 ± 0.1) × 10-6 M, and (3.2 ± 0.3) × 10-6 M/(2.7 ± 0.2) × 10-6 M were obtained in the presence of malathion, malaoxon and isomalathion, respectively. However, diethyl maleate inhibited AChE activity at concentrations >-10 mM, while O,O-dimethyl phosphate did not noticeably affect enzyme activity at all investigated concentrations. The relation between the structure of the compounds and their ability to inhibit enzyme activity was discussed.

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

    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 [11C]methylisocyanate with eseroline. [11C]Methylisocyanate was obtained by heating [11C]acetylchloride with tetrabutylammonium azide in toluene. The synthesis of [11C]CH3COC1 involves the carbonation of methylmagnesium bromide in THF with cyclotron produced [11C]carbon dioxide and the addition of phthaloyl dichloride. The [11C]methylisocyanate is distilled into a solution of eseroline in ether with a small piece of sodium. After 10 minutes at 25oC, the solution is purified by HPLC and the appropriate fraction collected. Starting with 55.5 GBq (1.5 Ci) of [11C]carbon dioxide, 0.92-1.48 GBq (25-40 mCi) of [11C]Physostigmine are obtained 57 minutes after EOB. (author)

  16. Simplified methods for in vivo measurement of acetylcholinesterase activity in rodent brain

    Simplified methods for in vivo studies of acetylcholinesterase (AChE) activity in rodent brain were evaluated using N-[11C]methylpiperidinyl propionate ([11C]PMP) as an enzyme substrate. Regional mouse brain distributions were determined at 1 min (representing initial brain uptake) and 30 min (representing trapped product) after intravenous [11C]PMP administration. Single time point tissue concentrations (percent injected dose/gram at 30 min), tissue concentration ratios (striatum/cerebellum and striatum/cortex ratios at 30 min), and regional tissue retention fractions (defined as percent injected dose 30 min/percent injected dose 1 min) were evaluated as measures of AChE enzymatic activity in mouse brain. Studies were carried out in control animals and after dosing with phenserine, a selective centrally active AChE inhibitor; neostigmine, a peripheral cholinesterase inhibitor; and a combination of the two drugs. In control and phenserine-treated animals, absolute tissue concentrations and regional retention fractions provide good measures of dose-dependent inhibition of brain AChE; tissue concentration ratios, however, provide erroneous conclusions. Peripheral inhibition of cholinesterases, which changes the blood pharmacokinetics of the radiotracer, diminishes the sensitivity of all measures to detect changes in central inhibition of the enzyme. We conclude that certain simple measures of AChE hydrolysis rates for [11C]PMP are suitable for studies where alterations of the peripheral blood metabolism of the tracer are kept to a minimum

  17. 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.

  18. Toxicity of azodrin on the morphology and acetylcholinesterase activity of the earthworm Eisenia foetida

    The acute toxicity of azodrin (monocrotophos, an organophosphorus insecticide) was determined on a soil organism, Eisenia foetida. The median lethal concentrations (LC50) were derived from a 48-h paper contact test and from artificial soil tests. The LC50 of azodrin in the paper contact test was 0.46±0.1 μg cm-2 (23±6 mg L-1) and those in the 7- and 14-day artificial soil tests were 171±21 and 132±20 mg kg-1, respectively. The neurotoxic potentiality of azodrin was assessed by using a marker enzyme, acetylcholinesterase (AChE; EC 3.1.1.7) in both in vitro and in vivo experiments. The progressive signs of morphological destruction are correlated with percentage inhibition of AChE in the in vivo experiments. The kinetics of AChE activity in the presence and absence of azodrin indicated that the toxicant is competitive in nature. This study demonstrated that azodrin causes concentration-dependent changes in the morphology and AChE activity of the earthworm E. foetida

  19. Diallyl tetrasulfide improves cadmium induced alterations of acetylcholinesterase, ATPases and oxidative stress in brain of rats

    Cadmium (Cd) is a neurotoxic metal, which induces oxidative stress and membrane disturbances in nerve system. The garlic compound diallyl tetrasulfide (DTS) has the cytoprotective and antioxidant activity against Cd induced toxicity. The present study was carried out to investigate the efficacy of DTS in protecting the Cd induced changes in the activity of acetylcholinesterase (AChE), membrane bound enzymes, lipid peroxidation (LPO) and antioxidant status in the brain of rats. In rats exposed to Cd (3 mg/kg/day subcutaneously) for 3 weeks, a significant (P +K+-ATPase, Mg2+-ATPase and Ca2+-ATPase) were observed in brain tissue. Oral administration of DTS (40 mg/kg/day) with Cd significantly (P < 0.05) diminished the levels of LPO and protein carbonyls and significantly (P < 0.05) increased the activities of ATPases, antioxidant enzymes, GSH and TSH in brain. These results indicate that DTS attenuate the LPO and alteration of antioxidant and membrane bound enzymes in Cd exposed rats, which suggest that DTS protects the brain function from toxic effects of Cd

  20. 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. PMID:27180103

  1. Statistical analysis of the fractal gating motions of the enzyme acetylcholinesterase

    Shen, T. Y.; Tai, Kaihsu; McCammon, J. Andrew

    2001-04-01

    The enzyme acetylcholinesterase has an active site that is accessible only by a ``gorge'' or main channel from the surface, and perhaps by secondary channels such as the ``back door.'' Molecular-dynamics simulations show that these channels are too narrow most of the time to admit substrate or other small molecules. Binding of substrates is therefore ``gated'' by structural fluctuations of the enzyme. Here, we analyze the fluctuations of these possible channels, as observed in the 10.8-ns trajectory of the simulation. The probability density function of the gorge proper radius (defined in the text) was calculated. A double-peak feature of the function was discovered and therefore two states with a threshold were identified. The relaxation (transition probability) functions of these two states were also calculated. The results revealed a power-law decay trend and an oscillation around it, which show properties of fractal dynamics with a ``complex exponent.'' The cross correlation of potential energy versus proper radius was also investigated. We discuss possible physical models behind the fractal protein dynamics; the dynamic hierarchical model for glassy systems is evaluated in detail.

  2. 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

  3. Statistical Analysis of the Fractal Gating Motions of the Enzyme Acetylcholinesterase

    Shen, T Y.(University of California, San Diego); Tai, Kaihsu (University of California, San Diego); Mccammon, Andy (University of California, San Diego)

    2001-03-20

    The enzyme acetylcholinesterase has an active site that is accessible only by a gorge or main channel from the surface, and perhaps by secondary channels such as the back door. Molecular-dynamics simulations show that these channels are too narrow most of the time to admit substrate or other small molecules. Binding of substrates is therefore gated by structural fluctuations of the enzyme. Here, we analyze the fluctuations of these possible channels, as observed in the 10.8-ns trajectory of the simulation. The probability density function of the gorge proper radius (defined in the text) was calculated. A double-peak feature of the function was discovered and therefore two states with a threshold were identified. The relaxation (transition probability) functions of these two states were also calculated. The results revealed a power-law decay trend and an oscillation around it, which show properties of fractal dynamics with a complex exponent. The cross correlation of potential energy versus proper radius was also investigated. We discuss possible physical models behind the fractal protein dynamics; the dynamic hierarchical model for glassy systems is evaluated in detail.

  4. Acetylcholinesterase and carbonic anhydrase isoenzymes I and II inhibition profiles of taxifolin.

    Gocer, Hulya; Topal, Fevzi; Topal, Meryem; Küçük, Murat; Teke, Dilek; Gülçin, İlhami; Alwasel, Saleh H; Supuran, Claudiu T

    2016-06-01

    Taxifolin, also known as dihydroquercetin, is a flavonoid commonly found in plants. Carbonic anhydrase (CA, EC 4.2.1.1) plays an important role in many critical physiological events including carbon dioxide (CO2)/bicarbonate ([Formula: see text]) respiration and pH regulation. There are 16 known CA isoforms in humans, of which human hCA isoenzymes I and II (hCA I and II) are ubiquitous cytosolic isoforms. In this study, the inhibition properties of taxifolin against the slow cytosolic isoenzyme hCA I, and the ubiquitous and dominant rapid cytosolic isoenzyme hCA II were studied. Taxifolin, as a naturally bioactive flavonoid, has a Ki of 29.2 nM against hCA I, and 24.2 nM against hCA II. For acetylcholinesterase enzyme (AChE) inhibition, Ki parameter of taxifolin was determined to be 16.7 nM. These results clearly show that taxifolin inhibited both CA isoenzymes and AChE at the nM levels. PMID:25893707

  5. 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. PMID:26921554

  6. 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. PMID:26536397

  7. 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

  8. Identification of novel acetylcholinesterase inhibitors: Indolopyrazoline derivatives and molecular docking studies.

    Chigurupati, Sridevi; Selvaraj, Manikandan; Mani, Vasudevan; Selvarajan, Kesavanarayanan Krishnan; Mohammad, Jahidul Islam; Kaveti, Balaji; Bera, Hriday; Palanimuthu, Vasanth Raj; Teh, Lay Kek; Salleh, Mohd Zaki

    2016-08-01

    The synthesis of novel indolopyrazoline derivatives (P1-P4 and Q1-Q4) has been characterized and evaluated as potential anti-Alzheimer agents through in vitro Acetylcholinesterase (AChE) inhibition and radical scavenging activity (antioxidant) studies. Specifically, Q3 shows AChE inhibition (IC50: 0.68±0.13μM) with strong DPPH and ABTS radical scavenging activity (IC50: 13.77±0.25μM and IC50: 12.59±0.21μM), respectively. While P3 exhibited as the second most potent compound with AChE inhibition (IC50: 0.74±0.09μM) and with DPPH and ABTS radical scavenging activity (IC50: 13.52±0.62μM and IC50: 13.13±0.85μM), respectively. Finally, molecular docking studies provided prospective evidence to identify key interactions between the active inhibitors and the AChE that furthermore led us to the identification of plausible binding mode of novel indolopyrazoline derivatives. Additionally, in-silico ADME prediction using QikProp shows that these derivatives fulfilled all the properties of CNS acting drugs. This study confirms the first time reporting of indolopyrazoline derivatives as potential anti-Alzheimer agents. PMID:27231830

  9. 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.

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

    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 μg L-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 μg L-1 during 24 h, and measured the AchE activity in brain and muscle. At 0.072 μg L-1 EDS swimming motility decreased relative to the control group after 45 h, while at 1.4 μg L-1 EDS swimming motility decreased after 24 h. AchE activity significantly decreased in muscle when J. multidentata were exposed to EDS above 0.072 μg L-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.

  11. Inhibition of Acetylcholinesterase Modulates NMDA Receptor Antagonist Mediated Alterations in the Developing Brain

    Ivo Bendix

    2014-03-01

    Full Text Available Exposure to N-methyl-d-aspartate (NMDA receptor antagonists has been demonstrated to induce neurodegeneration in newborn rats. However, in clinical practice the use of NMDA receptor antagonists as anesthetics and sedatives cannot always be avoided. The present study investigated the effect of the indirect cholinergic agonist physostigmine on neurotrophin expression and the extracellular matrix during NMDA receptor antagonist induced injury to the immature rat brain. The aim was to investigate matrix metalloproteinase (MMP-2 activity, as well as expression of tissue inhibitor of metalloproteinase (TIMP-2 and brain-derived neurotrophic factor (BDNF after co-administration of the non-competitive NMDA receptor antagonist MK801 (dizocilpine and the acetylcholinesterase (AChE inhibitor physostigmine. The AChE inhibitor physostigmine ameliorated the MK801-induced reduction of BDNF mRNA and protein levels, reduced MK801-triggered MMP-2 activity and prevented decreased TIMP-2 mRNA expression. Our results indicate that AChE inhibition may prevent newborn rats from MK801-mediated brain damage by enhancing neurotrophin-associated signaling pathways and by modulating the extracellular matrix.

  12. Scapaundulin C, a novel labdane diterpenoid isolated from Chinese liverwort Scapania undulate, inhibits acetylcholinesterase activity.

    Kang, Ya-Qi; Zhou, Jin-Chuan; Fan, Pei-Hong; Wang, Shu-Qi; Lou, Hong-Xiang

    2015-12-01

    In the present study, scapaundulin C (1), a new labdane diterpenoid, and four related known compounds scapaundulin A (2), 5α, 8α, 9α-trihydroxy-13E-labden-12-one (3), 5α, 8α-dihydroxy-13E-labden-12-one (4), and (13S)-15-hydroxylabd-8 (17)-en-19-oic acid (5), were isolated from the Chinese liverwort Scapania undulate (L.) Dum., using column chromatography. The structures of these compounds were determined on the basis of 1D- and 2D-NMR analyses. The acetylcholinesterase (AchE) inhibitory activity was evaluated using a bioautographic TLC assay and the cytotoxic activity was evaluated by the MTT method. All the compounds were reported for the first time to exhibit moderate AchE inhibitory activity with minimal inhibitory quantities ranging from 250 to 500 ng. All the compounds were tested for their cytotoxicity against five human tumor cell lines, A549, K562, A2780, Hela, and HT29, and compounds 3 and 4 exhibited moderate inhibitory effects on the growth of A2780 cells. PMID:26721712

  13. Calcium-activated butyrylcholinesterase in human skin protects acetylcholinesterase against suicide inhibition by neurotoxic organophosphates

    The human epidermis holds an autocrine acetylcholine production and degradation including functioning membrane integrated and cytosolic butyrylcholinesterase (BuchE). Here we show that BuchE activities increase 9-fold in the presence of calcium (0.5 x 10-3M) via a specific EF-hand calcium binding site, whereas acetylcholinesterase (AchE) is not affected. 45Calcium labelling and computer simulation confirmed the presence of one EF-hand binding site per subunit which is disrupted by H2O2-mediated oxidation. Moreover, we confirmed the faster hydrolysis by calcium-activated BuchE using the neurotoxic organophosphate O-ethyl-O-(4-nitrophenyl)-phenylphosphonothioate (EPN). Considering the large size of the human skin with 1.8 m2 surface area with its calcium gradient in the 10-3M range, our results implicate calcium-activated BuchE as a major protective mechanism against suicide inhibition of AchE by organophosphates in this non-neuronal tissue

  14. 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

  15. Assessment of Acetylcholinesterase Activity Using Indoxylacetate and Comparison with the Standard Ellman’s Method

    Kamil Kuca

    2011-04-01

    Full Text Available Assay of acetylcholinesterase (AChE activity plays an important role in diagnostic, detection of pesticides and nerve agents, in vitro characterization of toxins and drugs including potential treatments for Alzheimer’s disease. These experiments were done in order to determine whether indoxylacetate could be an adequate chromogenic reactant for AChE assay evaluation. Moreover, the results were compared to the standard Ellman’s method. We calculated Michaelis constant Km (2.06 × 10−4 mol/L for acetylthiocholine and 3.21 × 10−3 mol/L for indoxylacetate maximum reaction velocity Vmax (4.97 × 10−7 kat for acetylcholine and 7.71 × 10−8 kat for indoxylacetate for electric eel AChE. In a second part, inhibition values were plotted for paraoxon, and reactivation efficacy was measured for some standard oxime reactivators: obidoxime, pralidoxime (2-PAM and HI-6. Though indoxylacetate is split with lower turnover rate, this compound appears as a very attractive reactant since it does not show any chemical reactivity with oxime antidots and thiol used for the Ellman’s method. Thus it can be advantageously used for accurate measurement of AChE activity. Suitability of assay for butyrylcholinesterase activity assessment is also discussed.

  16. 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.

  17. Maternal caffeine exposure alters neuromotor development and hippocampus acetylcholinesterase activity in rat offspring.

    Souza, Ana Claudia; Souza, Andressa; Medeiros, Liciane Fernandes; De Oliveira, Carla; Scarabelot, Vanessa Leal; Da Silva, Rosane Souza; Bogo, Mauricio Reis; Capiotti, Katiucia Marques; Kist, Luiza Wilges; Bonan, Carla D; Caumo, Wolnei; Torres, Iraci L S

    2015-01-21

    The objective of this study was to evaluate the effects of maternal caffeine intake on the neuromotor development of rat offspring and on acetylcholine degradation and acetylcholinesterase (AChE) expression in the hippocampus of 14-day-old infant rats. Rat dams were treated with caffeine (0.3g/L) throughout gestation and lactation until the pups were 14 days old. The pups were divided into three groups: (1) control, (2) caffeine, and (3) washout caffeine. The washout group received a caffeine solution until the seventh postnatal day (P7). Righting reflex (RR) and negative geotaxis (NG) were assessed to evaluate postural parameters as an index of neuromotor reflexes. An open-field (OF) test was conducted to assess locomotor and exploratory activities as well as anxiety-like behaviors. Caffeine treatment increased both RR and NG latency times. In the OF test, the caffeine group had fewer outer crossings and reduced locomotion compared to control, while the washout group showed increased inner crossings in relation to the other groups and fewer rearings only in comparison to the control group. We found decreased AChE activity in the caffeine group compared to the other groups, with no alteration in AChE transcriptional regulation. Chronic maternal exposure to caffeine promotes important alterations in neuromotor development. These results highlight the ability of maternal caffeine intake to interfere with cholinergic neurotransmission during brain development. PMID:25451122

  18. 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.

  19. Increased Acetylcholinesterase Expression in Bumble Bees During Neonicotinoid-Coated Corn Sowing.

    Samson-Robert, Olivier; Labrie, Geneviève; Mercier, Pierre-Luc; Chagnon, Madeleine; Derome, Nicolas; Fournier, Valérie

    2015-01-01

    While honey bee exposure to systemic insecticides has received much attention, impacts on wild pollinators have not been as widely studied. Neonicotinoids have been shown to increase acetylcholinesterase (AChE) activity in honey bees at sublethal doses. High AChE levels may therefore act as a biomarker of exposure to neonicotinoids. This two-year study focused on establishing whether bumble bees living and foraging in agricultural areas using neonicotinoid crop protection show early biochemical signs of intoxication. Bumble bee colonies (Bombus impatiens) were placed in two different agricultural cropping areas: 1) control (≥ 3 km from fields planted with neonicotinoid-treated seeds) or 2) exposed (within 500 m of fields planted with neonicotinoid-treated seeds), and maintained for the duration of corn sowing. As determined by Real Time qPCR, AChE mRNA expression was initially significantly higher in bumble bees from exposed sites, then decreased throughout the planting season to reach a similar endpoint to that of bumble bees from control sites. These findings suggest that exposure to neonicotinoid seed coating particles during the planting season can alter bumble bee neuronal activity. To our knowledge, this is the first study to report in situ that bumble bees living in agricultural areas exhibit signs of neonicotinoid intoxication. PMID:26223214

  20. 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. PMID:27176468

  1. 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).

  2. Sub-chronic effect of neem based pesticide (Vepacide) on acetylcholinesterase and ATPases in rat.

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

    1999-09-01

    Acetylcholinesterases (AChE), Na(+)-K+, Mg2+ and Ca(2+)-ATPases were monitored in rat brain when treated orally with 80, 160 and 320 mg/kg of Vepacide, an active ingredient from neem seed oil, daily for 90 days. Brain AChE, Na(+)-K+ and Ca(2+)-ATPases were inhibited whereas Mg(2+)-ATPase levels were enhanced in both the sexes after 45 and 90 days of treatment. The relative sensitivities of these ATPases to Vepacide indicated that Ca(2+)-ATPase being more sensitive than Na(+)-K(+)-ATPase in both the sexes. The magnitude of Ca(2+)-ATPase inhibited by this compound was higher than that of brain AChE. It appears to be sexual dimorphism in the alterations of brain AChE, Na(+)-K+ and Mg(2+)-ATPases by Vepacide with females being significant when compared with males. After 28 days of post treatment the alterations observed were approached to those of controls both in male and female rats showing reversal of the toxicity. These results indicated that the ATPases were potently inhibited by Vepacide and seemed to be its precise target among the enzyme studied. This can be used as biochemical marker of exposure to this neem derived product. PMID:10466107

  3. Radiosynthesis and in vivo evaluation of fluorinated huprine derivates as PET radiotracers of acetylcholinesterase

    Introduction: Developing positron emission tomography (PET) radiotracers for non-invasive study of the cholinergic system is crucial to the understanding of neurodegenerative diseases. Although several acetylcholinesterase (AChE) PET tracers radiolabeled with carbon-11 exist, no fluorinated radiotracer is currently used in clinical imaging studies. The purpose of the present study is to describe the first fluorinated PET radiotracer for this brain enzyme. Methods: Three structural analogs of huprine, a specific AChE inhibitor presenting high affinity towards AChE in vitro, were synthesized and labeled with fluorine-18 via a mesylate/fluoro-nucleophilic aliphatic substitution: ([18 F]-FHUa, [18 F]-FHUb and [18 F]-FHUc). Initial biological evaluation included in vitro autoradiography in rat with competition with an AChE inhibitor at different concentrations, and microPET-scan on anesthetized rats. In vivo PET studies in anesthetized cat focused on [18 F]-FHUa. Results and Conclusions: Although radiosynthesis of these huprine analogs was straightforward, they showed poor brain penetration potential, partially reversed after pharmacological inhibition of P-glycoprotein. These results indicated that current huprine analogs are not suitable for PET mapping of brain AChE receptors, but require physicochemical modulation in order to increase brain penetration

  4. 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.

  5. An acetylcholinesterase-based chronoamperometric biosensor for fast and reliable assay of nerve agents.

    Pohanka, Miroslav; Adam, Vojtech; Kizek, Rene

    2013-01-01

    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. PMID:23999806

  6. Intraclonal variability in Daphnia acetylcholinesterase activity: the implications for its applicability as a biomarker.

    Printes, Liane Biehl; Callaghan, Amanda

    2003-09-01

    The relationship between individual growth and acetylcholinesterase (AChE) activity was evaluated for Daphnia magna. Analysis on the influence of two different culture media on baseline AChE activity was performed with Daphnia similis. The results indicated an inverse relationship between D. magna body length and AChE activity. An increase in total protein, which was not proportional to an increase in the rate of the substrate hydrolysis (delta absorbance/min), seems to be the reason for this inverse size versus AChE activity relationship. Therefore, toxicants such as phenobarbital, which affect protein and size but not AChE activity directly, have an overall affect on AChE activity. In contrast, the AChE inhibitor parathion altered AChE activity but not protein. Culture medium also had a significant affect on AChE activity in D. similis. Changes in total protein seem to be the main reason for the variations in baseline AChE activity in Daphnia observed in the different evaluations performed in this work. Therefore, AChE activity in Daphnia must be interpreted carefully, and variations related to changes in total protein must be taken into account when applying this enzyme as a biomarker in biological monitoring. PMID:12959529

  7. Resveratrol- and α-viniferin-induced alterations of acetylcholinesterase and nitric oxide synthase in Raillietina echinobothrida.

    Giri, Bikash Ranjan; Roy, Bishnupada

    2015-10-01

    Phytostilbenes, like resveratrol and α-viniferin, which occur mainly in the plants and belong to the families Cyperaceae, Vitaceae, and Gnetaceae are extensively popular for their medicinal and nutritional properties. In Northeast India, the Jaintia tribes consume these phytochemicals through aqueous extract of the medicinal plant Carex baccans to control helminthiasis. The present study aimed to investigate the inhibitory effect of the phytochemicals on neurotransmitters and its related enzymes in helminth parasite Raillietina echinobothrida. Viability of the parasites exposed to the phytostilbenes and extent of inhibition of cholinergic and nitrergic enzymes were evaluated in comparison to reference anthelmintic drug praziquantel and two known enzyme inhibitors, namely Nω-nitro-L-arginine and pyridostigmine. On exposure to resveratrol, α-viniferin, and reference drug praziquantel, the parasites ceased movement at 9.37, 11.38, and 0.24 h followed by death at 23.65, 34.13, and 1.87 h, respectively. Exposed parasites also showed a significant decrease in the activity of acetylcholinesterase (46.101, 65.935, and 63.645%) and nitric oxide synthase (61.241, 55.046, and 29.618%) in comparison to the controls. In addition, a decreased trend in nitric oxide (NO) level was also detected in the tissue of different phytochemical-exposed parasites compared to control. The present study suggests that anthelmintic potential of both the phytochemicals is mediated through inhibition of two vital enzymes which play diverse role in intracellular communications through neuromuscular system. PMID:26141435

  8. 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. PMID:26585089

  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. 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.

  11. Immobilization of acetylcholinesterase via biocompatible interface of silk fibroin for detection of organophosphate and carbamate pesticides

    Xue, Rui; Kang, Tian-Fang; Lu, Li-Ping; Cheng, Shui-Yuan

    2012-06-01

    An amperometric biosensor for the detection of organophosphate and carbamate pesticides was developed based on the immobilization of acetylcholinesterase (AChE) on regenerated silk fibroin (SF) matrix by non-covalent adsorption. SF and AChE were coated sequentially on the surface of the glassy carbon electrode (GCE) which was modified with multiwall carbon nanotube (MWNTs). The obtained biosensor was denoted as AChE-SF/MWNTs/GCE. The atomic force microscopy images showed that the SF matrix provided a more homogeneous interface for the AChE immobilization. The aggregation of immobilizing AChE was therefore avoided. The cyclic voltammogram of thiocholine at this biosensor exhibited a well defined oxidation peak at 0.667 V (vs. SCE). The inhibition rate of methyl parathion to the immobilized AChE was proportional to the logarithm of the concentration of methyl parathion over the range of the concentration of methyl parathion from 3.5 × 10-6 to 2.0 × 10-3 M with a detection limit of 5.0 × 10-7 M. Similarly, the linearly response range of carbaryl was from 1.0 × 10-7 to 3.0 × 10-5 M with a detection limit of 6.0 × 10-8 M. The experimental results indicate that AChE not only can be immobilized steadily on the SF matrix, but also the bioactivity of immobilizing AChE can be preserved effectively.

  12. Nature of stress: differential effects on brain acetylcholinesterase activity and memory in rats.

    Das, Amitava; Rai, Deepak; Dikshit, Madhu; Palit, Gautam; Nath, Chandishwar

    2005-09-16

    Effect of acute, chronic-predictable and chronic-unpredictable stress on memory and acetylcholinesterase (AChE) was investigated in rats. The animals were subjected to 3 type of stressors--(1) acute immobilization stress, (2) chronic-predictable stress i.e., immobilization daily for 5 consecutive days and (3) chronic-unpredictable stress that included reversal of light/dark cycle, over-night fasting, forced-swimming, immobilization and forced exercise in random unpredictable manner daily for 5 consecutive days. Learning and memory function was studied by single trial Passive avoidance test. AChE activity was assayed spectrophotometrically in the detergent (DS) and salt (SS) soluble fractions in different brain regions. Learning was obtained in acute and chronic-predictable stress groups but not in chronic-unpredictable group. Acute, chronic-predictable and chronic-unpredictable stress caused significant decrease in AChE activity in the DS fraction of cortex, hippocampus and hypothalamus as compared to control. Results indicate that AChE in DS fraction is predominantly affected in stressed and stressed-trained group but cognition is affected only by chronic-unpredictable stress. In acute and chronic-predictable groups the decreased AChE activity in the hippocampal DS fraction during learning may be responsible to maintain cognitive function by enhancing the cholinergic activity. PMID:16098992

  13. Histochemical study of the pre—and postnatal development of acetylcholinesterase in the rat spinal cord

    ZHANGQIN; XINWENDONG; 等

    1993-01-01

    The distribution of acetylcholinesterase(AChE)-positive structures in the developing rat spinal cord was studied with AChE-histochemistry.AChE-positive perikarya were first seen on embryonic day 14(E14) in the ventrolateral portion of the spinal cord.From that time onward.AChE=containing cells appeared gradually in the intermediate gray,dorsal horn and lateral spinal nucleus of the spinal cord in a ventral-to-dorsal,and lateral-to-medial order.No obvious rostral-to-caudal sequence was found.At birth,the distribution pattern of AChE-positive perikarya was basically similar to that in adults.After birth a dramatic increase in the AChE staining intensity extended from postnatal day 5(P5) to postnatal day 21(P21),In addition,two phases of transient AChE staining were observed in the external surface of the dorsal horn from embryonic day 15(E15) to embryonic day 21(E21) and in the marginal layer from embryonic day 21(E21) to postnatal day 14(P14),respectively.

  14. 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. PMID:25342379

  15. 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. PMID:23424099

  16. 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. PMID:26516688

  17. 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.

  18. Inhibition of rainbow trout acetylcholinesterase by aqueous and suspended particle-associated organophosphorous insecticides.

    Sturm, Armin; Radau, Tanja S; Hahn, Torsten; Schulz, Ralf

    2007-06-01

    Spraydrift and edge-of-field runoff are important routes of pesticide entry into streams. Pesticide contamination originating from spraydrift usually resides in the water phase, while pesticides in contaminated runoff are to a large extent associated with suspended particles (SPs). The effects of two organophosphorous insecticides (OPs), chloropyrifos (CPF) and azinphos-methyl (AZP), on acetylcholinesterase (AChE) activity in rainbow trout were compared between two exposure scenarios, simulating spraydrift- and runoff-borne contamination events in the Lourens River (LR), Western Cape, South Africa. NOECs of brain AChE inhibition, determined after 1h of exposure followed by 24h of recovery, were 0.33microgl(-1) for aqueous CPF, 200mgkg(-1) for SP-associated CPF and 20mgkg(-1) for SP-associated AZP (at 0.5gl(-1) SP). The highest aqueous AZP concentration tested (3.3microgl(-1)) was without significant effects. Previously reported peak levels of aqueous CPF in the LR ( approximately 0.2microgl(-1)) are close to its NOEC (this study), suggesting a significant toxicological risk to fish in the LR. By contrast, reported levels of SP-associated OPs in the LR are 20-200-fold lower than their NOECs (this study). In a comparative in situ study, trout were exposed for seven days at agricultural (LR2, LR3) and upstream reference (LR1) sites. No runoff occurred during the study. Brain AChE was significantly inhibited at LR3. However, OP levels at LR3 (CPF 0.01microgl(-1); AZP 0.14microgl(-1)) were minor compared to concentrations having effects in the laboratory (see above). Additionally, muscle AChE activity was significantly higher in caged trout from LR1 than in animals maintained in laboratory tanks. PMID:17418885

  19. 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.

  20. Calretinin immunohistochemistry versus improvised rapid Acetylcholinesterase histochemistry in the evaluation of colorectal biopsies for Hirschsprung disease

    Lokendra Yadav

    2014-01-01

    Full Text Available Background: Acetylcholinesterase (AChE histochemistry on rectal mucosal biopsies accurately diagnoses Hirschsprung disease (HD, but is not widely employed as it requires special tissue handling and pathologist expertise. Calretinin immunohistochemistry (IHC has been reported to be comparable to AChE staining with the loss of expression correlating with aganglionosis. Aim: The aim was to evaluate calretinin IHC as a primary diagnostic tool in comparison to the improvised rapid AChE technique in the diagnosis of HD. Materials and Methods: A total of 74 rectal biopsies (18 fresh frozen - 18 cases, 56 formalin fixed - 33 cases from 51 cases of suspect HD were evaluated with hematoxylin and eosin/AChE/Calretinin. Ten biopsies each from ganglionated and aganglionated segments served as positive and negative controls. Ileal (3, appendiceal (3 and ring bowel (2 biopsies were also included. Two pathologists blinded to the clinical details evaluated the histomorphology with AChE and calretinin. Observations were statistically analyzed and Cohen′s k coefficient employed to assess agreement between two pathologists and calretinin and the AChE. Results: The study confirmed HD in 26 and non-HD in 25 cases. There were 7 neonates, 5 low level biopsies and 14 "inadequate" biopsies. The results of calretinin were comparable with AChE with a statistically significant measure of agreement of k = 0.973 between the two. One false-positive case of HD was noted with calretinin. The advantages and disadvantages of calretinin versus AChE are discussed. Conclusion: Calretinin is a reliable single immune marker for ruling out HD by its specific positive mucosal staining of formalin fixed rectal biopsy. The improvised AChE staining remains indispensable to confirm HD on fresh biopsies and thus, along with calretinin IHC maximizes the diagnostic accuracy of HD in difficult cases.

  1. 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. PMID:24479629

  2. Immobilization of acetylcholinesterase via biocompatible interface of silk fibroin for detection of organophosphate and carbamate pesticides

    Xue Rui [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Kang Tianfang, E-mail: kangtf@yahoo.cn [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Lu Liping; Cheng Shuiyuan [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China)

    2012-06-01

    An amperometric biosensor for the detection of organophosphate and carbamate pesticides was developed based on the immobilization of acetylcholinesterase (AChE) on regenerated silk fibroin (SF) matrix by non-covalent adsorption. SF and AChE were coated sequentially on the surface of the glassy carbon electrode (GCE) which was modified with multiwall carbon nanotube (MWNTs). The obtained biosensor was denoted as AChE-SF/MWNTs/GCE. The atomic force microscopy images showed that the SF matrix provided a more homogeneous interface for the AChE immobilization. The aggregation of immobilizing AChE was therefore avoided. The cyclic voltammogram of thiocholine at this biosensor exhibited a well defined oxidation peak at 0.667 V (vs. SCE). The inhibition rate of methyl parathion to the immobilized AChE was proportional to the logarithm of the concentration of methyl parathion over the range of the concentration of methyl parathion from 3.5 Multiplication-Sign 10{sup -6} to 2.0 Multiplication-Sign 10{sup -3} M with a detection limit of 5.0 Multiplication-Sign 10{sup -7} M. Similarly, the linearly response range of carbaryl was from 1.0 Multiplication-Sign 10{sup -7} to 3.0 Multiplication-Sign 10{sup -5} M with a detection limit of 6.0 Multiplication-Sign 10{sup -8} M. The experimental results indicate that AChE not only can be immobilized steadily on the SF matrix, but also the bioactivity of immobilizing AChE can be preserved effectively.

  3. 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.

  4. Characterization of acetylcholinesterase inhibition and energy allocation in Daphnia magna exposed to carbaryl.

    Jeon, Junho; Kretschmann, Andreas; Escher, Beate I; Hollender, Juliane

    2013-12-01

    The inhibition of acetylcholinesterase (AChE) activity and energy allocation in the freshwater organism Daphnia magna exposed to carbaryl and potential recovery from the effects was examined. The binding of carbaryl-AChE was characterized through in vitro assays. To evaluate the recovery from inhibition and the alteration in energy budget, in vivo exposure and recovery regime tests were conducted. In comparison to diazoxon, the active metabolite of the insecticide diazinon, the stability of enzyme-carbaryl complex was fifteen times lower and the reactivity toward the active site was two times lower, resulting in approximately 30 times lower overall inhibition rate than for diazoxon. The in vitro reactivation rate constant of the inhibited enzyme and the in vivo recovery rate constant of AChE activity were 1.9 h⁻¹ and 0.12 h⁻¹ for carbaryl, respectively, which are much higher than the corresponding rate constants for diazoxon. The lower AChE inhibition and greater reactivation/recovery rates are in accordance with the lower toxicity of carbaryl compared to diazinon. Carbaryl exposure also altered the profile of the energy reserve: the decrease in lipid and glycogen and the increase in protein content resulted in the reduction of the total energy budget by about 45 mJ/g(ww). This corresponds to 26 percent of the available energy, which might allocate for external stressors. The mechanistic model of AChE inhibition is helpful to get an insight into (eco-)toxicological effects of AChE inhibitors on freshwater crustaceans under environmentally realistic conditions. PMID:24139064

  5. In vitro inhibitory effect of aflatoxin B1 on acetylcholinesterase activity in mouse brain.

    Cometa, Maria Francesca; Lorenzini, Paola; Fortuna, Stefano; Volpe, Maria Teresa; Meneguz, Annarita; Palmery, Maura

    2005-01-01

    Growing concern on the problem of mycotoxins in the alimentary chain underlines the need to investigate the mechanisms explaining the cholinergic effects of aflatoxin B(1) (AFB(1)). We examined the effect of AFB(1), a mycotoxin produced by Aspergillus flavus, on mouse brain acetylcholinesterase (AChE) and specifically on its molecular isoforms (G(1) and G(4)) after in vitro exposure. AFB(1) (from 10(-9) to 10(-4)M), inhibited mouse brain AChE activity (IC(50) = 31.6 x 10(-6)M) and its G(1) and G(4) molecular isoforms in a dose-dependent manner. Michaelis-Menten parameters indicate that the K(m) value increased from 55.2 to 232.2% whereas V(max) decreased by 46.2-75.1%. The direct, the Lineweaver-Burk and the secondary plots indicated a non-competitive-mixed type antagonism, induced when the inhibitor binds to the free enzyme and to the enzyme-substrate complex. AFB(1)-inhibited AChE was partially reactivated by pyridine 2-aldoxime (2-PAM) (10(-4)M) but the AChE-inhibiting time courses of AFB(1) (10(-4)M) and diisopropylfluorophosphate (DFP) (2 x 10(-7)M) differed. Overall these data suggest that AFB(1) non-competitively inhibits mouse brain AChE by blocking access of the substrate to the active site or by inducing a defective conformational change in the enzyme through non-covalent binding interacting with the AChE peripheral binding site, or through both mechanisms. PMID:15590113

  6. 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.

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

    Yokota, Shin-Ichi; Nakamura, Kaai; Ando, Midori; Kamei, Hiroyasu; Hakuno, Fumihiko; Takahashi, Shin-Ichiro; Shibata, Shigenobu

    2014-01-01

    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. PMID:25383314

  8. Inhibition of acetylcholinesterase by two genistein derivatives: kinetic analysis, molecular docking and molecular dynamics simulation.

    Fang, Jiansong; Wu, Ping; Yang, Ranyao; Gao, Li; Li, Chao; Wang, Dongmei; Wu, Song; Liu, Ai-Lin; Du, Guan-Hua

    2014-12-01

    In this study two genistein derivatives (G1 and G2) are reported as inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), and differences in the inhibition of AChE are described. Although they differ in structure by a single methyl group, the inhibitory effect of G1 (IC50=264 nmol/L) on AChE was 80 times stronger than that of G2 (IC50=21,210 nmol/L). Enzyme-kinetic analysis, molecular docking and molecular dynamics (MD) simulations were conducted to better understand the molecular basis for this difference. The results obtained by kinetic analysis demonstrated that G1 can interact with both the catalytic active site and peripheral anionic site of AChE. The predicted binding free energies of two complexes calculated by the molecular mechanics/generalized born surface area (MM/GBSA) method were consistent with the experimental data. The analysis of the individual energy terms suggested that a difference between the net electrostatic contributions (ΔE ele+ΔG GB) was responsible for the binding affinities of these two inhibitors. Additionally, analysis of the molecular mechanics and MM/GBSA free energy decomposition revealed that the difference between G1 and G2 originated from interactions with Tyr124, Glu292, Val294 and Phe338 of AChE. In conclusion, the results reveal significant differences at the molecular level in the mechanism of inhibition of AChE by these structurally related compounds. PMID:26579414

  9. 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.

  10. Human serum albumin reduces the potency of acetylcholinesterase inhibitor based drugs for Alzheimer's disease.

    Islam, Mullah Muhaiminul; Gurung, Arun Bahadur; Bhattacharjee, Atanu; Aguan, Kripamoy; Mitra, Sivaprasad

    2016-04-01

    Human serum albumin (HSA) induced modulation of acetylcholinesterase (AChE) inhibition activity of four well-known cholinergic inhibitors like tacrine hydrochloride (TAC), donepezil hydrochloride monohydrate (DON), (-) Huperzine A (HuPA), eserine (ESE) was monitored quantitatively by Ellman's method. Kinetic analysis of enzyme hydrolysis reaction revealed that while the mechanism of inhibition does not change significantly, the inhibition efficiency changes drastically in presence of HSA, particularly for DON and TAC. However, interestingly, no notable difference was observed in the cases of HuPA and/or ESE. For example, the IC50 value of AChE inhibition increases by almost 135% in presence of ∼250 μM HSA (IC50 = 159 ± 8 nM) while comparing with aqueous buffer solution of pH 8.0 (IC50 = 68 ± 4 nM) in DON. On the other hand, the change is almost insignificant (<10%) in case of HuPA under the similar condition. The experimentally observed difference in the extent of modulatory effect was correlated with the sequestration ability of HSA towards different drugs predicted from molecular docking calculations. The result in this study demonstrates the importance to consider the plasma protein binding tendency of a newly synthesized AD drug before claiming its potency over the existing one. Further, development of new and intelligent delivery medium that shields the administered drugs from serum adsorption may reduce the optimal drug dose requirement. PMID:26902639

  11. Transcriptional activity of acetylcholinesterase gene is regulated by DNA methylation during C2C12 myogenesis.

    Lau, Kei M; Gong, Amy G W; Xu, Miranda L; Lam, Candy T W; Zhang, Laura M L; Bi, Cathy W C; Cui, D; Cheng, Anthony W M; Dong, Tina T X; Tsim, Karl W K; Lin, Huangquan

    2016-07-01

    The expression of acetylcholinesterase (AChE), an enzyme hydrolyzes neurotransmitter acetylcholine at vertebrate neuromuscular junction, is regulated during myogenesis, indicating the significance of muscle intrinsic factors in controlling the enzyme expression. DNA methylation is essential for temporal control of myogenic gene expression during myogenesis; however, its role in AChE regulation is not known. The promoter of vertebrate ACHE gene carries highly conserved CG-rich regions, implying its likeliness to be methylated for epigenetic regulation. A DNA methyltransferase inhibitor, 5-azacytidine (5-Aza), was applied onto C2C12 cells throughout the myotube formation. When DNA methylation was inhibited, the promoter activity, transcript expression and enzymatic activity of AChE were markedly increased after day 3 of differentiation, which indicated the putative role of DNA methylation. By bisulfite pyrosequencing, the overall methylation rate was found to peak at day 3 during C2C12 cell differentiation; a SP1 site located at -1826bp upstream of mouse ACHE gene was revealed to be heavily methylated. The involvement of transcriptional factor SP1 in epigenetic regulation of AChE was illustrated here: (i) the SP1-driven transcriptional activity was increased in 5-Aza-treated C2C12 culture; (ii) the binding of SP1 onto the SP1 site of ACHE gene was fully blocked by the DNA methylation; and (iii) the sequence flanking SP1 sites of ACHE gene was precipitated by chromatin immuno-precipitation assay. The findings suggested the role of DNA methylation on AChE transcriptional regulation and provided insight in elucidating the DNA methylation-mediated regulatory mechanism on AChE expression during muscle differentiation. PMID:27021952

  12. Design and prediction of new acetylcholinesterase inhibitor via quantitative structure activity relationship of huprines derivatives.

    Zhang, Shuqun; Hou, Bo; Yang, Huaiyu; Zuo, Zhili

    2016-05-01

    Acetylcholinesterase (AChE) is an important enzyme in the pathogenesis of Alzheimer's disease (AD). Comparative quantitative structure-activity relationship (QSAR) analyses on some huprines inhibitors against AChE were carried out using comparative molecular field analysis (CoMFA), comparative molecular similarity indices analysis (CoMSIA), and hologram QSAR (HQSAR) methods. Three highly predictive QSAR models were constructed successfully based on the training set. The CoMFA, CoMSIA, and HQSAR models have values of r (2) = 0.988, q (2) = 0.757, ONC = 6; r (2) = 0.966, q (2) = 0.645, ONC = 5; and r (2) = 0.957, q (2) = 0.736, ONC = 6. The predictabilities were validated using an external test sets, and the predictive r (2) values obtained by the three models were 0.984, 0.973, and 0.783, respectively. The analysis was performed by combining the CoMFA and CoMSIA field distributions with the active sites of the AChE to further understand the vital interactions between huprines and the protease. On the basis of the QSAR study, 14 new potent molecules have been designed and six of them are predicted to be more active than the best active compound 24 described in the literature. The final QSAR models could be helpful in design and development of novel active AChE inhibitors. PMID:26832327

  13. 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.

  14. Drosophila acetylcholinesterase: demonstration of a glycoinositol phospholipid anchor and an endogenous proteolytic cleavage

    The presence of a glycoinositol phospholipid anchor Drosophila acetylcholinesterase (AChE) was shown by several criteria. Chemical analysis of highly purified Drosophila AChE demonstrated approximately one residue of inositol per enzyme subunit. Selective cleavage by Staphylococcus aureus phosphatidylinositol-specific phospholipase C (PI-PLC) was tested with Drosophila AChE radiolabeled by the photoactivatable affinity probe 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine ([125I]TID), a reagent that specifically labels the lipid moiety of glycoinositol phospholipid-anchored proteins. Digestion with PI-PLC released 75% of this radiolabel from the protein. Gel electrophoresis of Drosophila AChE in sodium dodecyl sulfate indicated prominent 55- and 16-kDa bands and a faint 70-kDa band. The [125]I]TID label was localized on the 55-kDa fragment, suggesting that this fragment is the C-terminal portion of the protein. In support of this conclusion, a sensitive microsequencing procedure that involved manual Edman degradation combined with radiomethylation was used to determine residues 2-5 of the 16-kDa fragment. Comparison with the Drosophila AChE cDNA sequence confirmed that the 16-kDa fragment includes the N-terminus of AChE. Furthermore, the position of the N-terminal amino acid of the mature Drosophila AChE is closely homologous to that of Torpedo AChE. The presence of radiomethylatable ethanolamine in both 16- and 55-kDa fragments was also confirmed. Thus, Drosophila AChE may include a second posttranslational modification involving ethanolamine

  15. Mouse acetylcholinesterase enhances neurite outgrowth of rat R28 cells through interaction with laminin-1.

    Laura E Sperling

    Full Text Available The enzyme acetylcholinesterase (AChE terminates synaptic transmission at cholinergic synapses by hydrolyzing the neurotransmitter acetylcholine, but can also exert 'non-classical', morpho-regulatory effects on developing neurons such as stimulation of neurite outgrowth. Here, we investigated the role of AChE binding to laminin-1 on the regulation of neurite outgrowth by using cell culture, immunocytochemistry, and molecular biological approaches. To explore the role of AChE, we examined fiber growth of cells overexpressing different forms of AChE, and/or during their growth on laminin-1. A significant increase of neuritic growth as compared with controls was observed for neurons over-expressing AChE. Accordingly, addition of globular AChE to the medium increased total length of neurites. Co-transfection with PRIMA, a membrane anchor of AChE, led to an increase in fiber length similar to AChE overexpressing cells. Transfection with an AChE mutant that leads to the retention of AChE within cells had no stimulatory effect on neurite length. Noticeably, the longest neurites were produced by neurons overexpressing AChE and growing on laminin-1, suggesting that the AChE/laminin interaction is involved in regulating neurite outgrowth. Our findings demonstrate that binding of AChE to laminin-1 alters AChE activity and leads to increased neurite growth in culture. A possible mechanism of the AChE effect on neurite outgrowth is proposed due to the interaction of AChE with laminin-1.

  16. The protective role of tacrine and donepezil in the retina of acetylcholinesterase knockout mice

    Yun-Min Yi

    2015-10-01

    Full Text Available AIM:To determine the effect of different concentrations of the acetylcholinesterase (AChE inhibitors tacrine and donepezil on retinal protection in AChE+/- mice (AChE knockout mice of various ages.METHODS:Cultured ARPE-19 cells were treated with hydrogen peroxide (H2O2 at concentrations of 0, 250, 500, 1000 and 2000 μmol/L and protein levels were measured using Western blot. Intraperitoneal injections of tacrine and donepezil (0.1 mg/mL, 0.2 mg/mL and 0.4 mg/mL were respectively given to AChE+/- mice aged 2mo and 4mo and wild-type S129 mice for 7d; phosphate buffered saline (PBS was administered to the control group. The mice were sacrificed after 30d by in vitro cardiac perfusion and retinal samples were taken. AChE-deficient mice were identified by polymerase chain reaction (PCR analysis using specific genotyping protocols obtained from the Jackson Laboratory website. H&E staining, immunofluorescence and Western blot were performed to observe AChE protein expression changes in the retinal pigment epithelial (RPE cell layer.RESULTS:Different concentrations of H2O2 induced AChE expression during RPE cell apoptosis. AChE+/- mice retina were thinner than those in wild-type mice (P<0.05; the retinal structure was still intact at 2mo but became thinner with increasing age (P<0.05; furthermore, AChE+/- mice developed more slowly than wild-type mice (P<0.05. Increased concentrations of tacrine and donepezil did not significantly improve the protection of the retina function and morphology (P>0.05.CONCLUSION:In vivo, tacrine and donepezil can inhibit the expression of AChE; the decrease of AChE expression in the retina is beneficial for the development of the retina.

  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. Overexpression of acetylcholinesterase gene in rice results in enhancement of shoot gravitropism.

    Yamamoto, Kosuke; Shida, Satoshi; Honda, Yoshihiro; Shono, Mariko; Miyake, Hiroshi; Oguri, Suguru; Sakamoto, Hikaru; Momonoki, Yoshie S

    2015-09-25

    Acetylcholine (ACh), a known neurotransmitter in animals and acetylcholinesterase (AChE) exists widely in plants, although its role in plant signal transduction is unclear. We previously reported AChE in Zea mays L. might be related to gravitropism based on pharmacological study using an AChE inhibitor. Here we clearly demonstrate plant AChE play an important role as a positive regulator in the gravity response of plants based on a genetic study. First, the gene encoding a second component of the ACh-mediated signal transduction system, AChE was cloned from rice, Oryza sativa L. ssp. Japonica cv. Nipponbare. The rice AChE shared high homology with maize, siratro and Salicornia AChEs. Similar to animal and other plant AChEs, the rice AChE hydrolyzed acetylthiocholine and propionylthiocholine, but not butyrylthiocholine. Thus, the rice AChE might be characterized as an AChE (E.C.3.1.1.7). Similar to maize and siratro AChEs, the rice AChE exhibited low sensitivity to the AChE inhibitor, neostigmine bromide, compared with the electric eel AChE. Next, the functionality of rice AChE was proved by overexpression in rice plants. The rice AChE was localized in extracellular spaces of rice plants. Further, the rice AChE mRNA and its activity were mainly detected during early developmental stages (2 d-10 d after sowing). Finally, by comparing AChE up-regulated plants with wild-type, we found that AChE overexpression causes an enhanced gravitropic response. This result clearly suggests that the function of the rice AChE relate to positive regulation of gravitropic response in rice seedlings. PMID:26277389

  19. Human cerebral acetylcholinesterase activity measured with positron emission tomography: procedure, normal values and effect of age

    The regional cerebral metabolic rate of [11C]N-methyl-4-piperidyl acetate, which is nearly proportional to regional cerebral acetylcholinesterase (AChE) activity, was measured by dynamic positron emission tomography in 20 healthy subjects with a wide age range (24-89 years). Quantitative measurement was achieved using a kinetic model which consisted of arterial plasma and cerebral tissue compartments. The plasma input function was obtained using thin-layer chromatography and an imaging phosphor plate system at frequent sampling intervals to catch the rapid metabolism of the tracer in the blood. The distribution of the rate constant k3, an index of AChE activity, agreed well with reported post-mortem AChE distribution in the cerebral cortex (0.067-0.097 min-1) and thalamus (0.268 min-1), where AChE activity was low to moderate. The k3 values in the striatum and cerebellum, where AChE activity was very high, did not respond linearly to AChE activity because of increased flow dependency. No significant effect of age was found on AChE activity of the cerebral cortex, suggesting that the ascending central cholinergic system is preserved in normal aging. This study has shown that quantitative measurement of enzyme activity in the living brain is possible through appropriate modelling of tracer kinetics and accurate measurement of the input function. The method should be applicable to patients with Alzheimer's disease and those with other kinds of dementia whose central cholinergic system has been reported to be disturbed. (orig.)

  20. Human cerebral acetylcholinesterase activity measured with positron emission tomography: procedure, normal values and effect of age

    Namba, Hiroki [Advanced Technology for Medical Imaging, National Institute of Radiological Sciences, Chiba (Japan)]|[Division of Neurological Surgery, Chiba Cancer Center, Chiba (Japan); Iyo, Masaomi [Advanced Technology for Medical Imaging, National Institute of Radiological Sciences, Chiba (Japan)]|[Department of Psychiatry and Neurology, Hamamatsu University School of Medicine, Hamamatsu (Japan); Fukushi, Kiyoshi; Suhara, Tetsuya; Sudo, Yasuhiko; Suzuki, Kazutoshi; Irie, Toshiaki [Advanced Technology for Medical Imaging, National Institute of Radiological Sciences, Chiba (Japan); Shinotoh, Hitoshi [Advanced Technology for Medical Imaging, National Institute of Radiological Sciences, Chiba (Japan)]|[Department of Neurology, Chiba University School of Medicine, Chiba (Japan); Nagatsuka, Shin-ichiro [Advanced Technology for Medical Imaging, National Institute of Radiological Sciences, Chiba (Japan)]|[Tokai Research Laboratories, Daiichi Pure Chemical Co., Ltd., Ibaraki (Japan)

    1999-02-01

    The regional cerebral metabolic rate of [{sup 11}C]N-methyl-4-piperidyl acetate, which is nearly proportional to regional cerebral acetylcholinesterase (AChE) activity, was measured by dynamic positron emission tomography in 20 healthy subjects with a wide age range (24-89 years). Quantitative measurement was achieved using a kinetic model which consisted of arterial plasma and cerebral tissue compartments. The plasma input function was obtained using thin-layer chromatography and an imaging phosphor plate system at frequent sampling intervals to catch the rapid metabolism of the tracer in the blood. The distribution of the rate constant k{sub 3}, an index of AChE activity, agreed well with reported post-mortem AChE distribution in the cerebral cortex (0.067-0.097 min{sup -1}) and thalamus (0.268 min{sup -1}), where AChE activity was low to moderate. The k{sub 3} values in the striatum and cerebellum, where AChE activity was very high, did not respond linearly to AChE activity because of increased flow dependency. No significant effect of age was found on AChE activity of the cerebral cortex, suggesting that the ascending central cholinergic system is preserved in normal aging. This study has shown that quantitative measurement of enzyme activity in the living brain is possible through appropriate modelling of tracer kinetics and accurate measurement of the input function. The method should be applicable to patients with Alzheimer`s disease and those with other kinds of dementia whose central cholinergic system has been reported to be disturbed. (orig.) With 8 figs., 1 tab., 21 refs.

  1. Chlorpyrifos and chlorpyrifos-oxon inhibit axonal growth by interfering with the morphogenic activity of acetylcholinesterase

    A primary role of acetylcholinesterase (AChE) is regulation of cholinergic neurotransmission by hydrolysis of synaptic acetylcholine. In the developing nervous system, however, AChE also functions as a morphogenic factor to promote axonal growth. This raises the question of whether organophosphorus pesticides (OPs) that are known to selectively bind to and inactivate the enzymatic function of AChE also interfere with its morphogenic function to perturb axonogenesis. To test this hypothesis, we exposed primary cultures of sensory neurons derived from embryonic rat dorsal root ganglia (DRG) to chlorpyrifos (CPF) or its oxon metabolite (CPFO). Both OPs significantly decreased axonal length at concentrations that had no effect on cell viability, protein synthesis or the enzymatic activity of AChE. Comparative analyses of the effects of CPF and CPFO on axonal growth in DRG neurons cultured from AChE nullizygous (AChE-/-) versus wild type (AChE+/+) mice indicated that while these OPs inhibited axonal growth in AChE+/+ DRG neurons, they had no effect on axonal growth in AChE-/- DRG neurons. However, transfection of AChE-/- DRG neurons with cDNA encoding full-length AChE restored the wild type response to the axon inhibitory effects of OPs. These data indicate that inhibition of axonal growth by OPs requires AChE, but the mechanism involves inhibition of the morphogenic rather than enzymatic activity of AChE. These findings suggest a novel mechanism for explaining not only the functional deficits observed in children and animals following developmental exposure to OPs, but also the increased vulnerability of the developing nervous system to OPs

  2. Effects of Roundup Transorb on fish: hematology, antioxidant defenses and acetylcholinesterase activity.

    Modesto, Kathya A; Martinez, Cláudia B R

    2010-10-01

    Roundup Transorb(RDT) is a glyphosate-based herbicide containing a mixture of surfactants. The objective of this work was to evaluate the effects of this herbicide on the Neotropical fish Prochilodus lineatus. Juvenile fish were acutely exposed (6, 24 and 96 h) to 1 mg L(-1) of RDT (RDT 1), 5 mg L(-1) of RDT (RDT 5) or only water (control) and blood samples for hematological analysis, liver for antioxidants analysis, and brain and muscle for acetylcholinesterase (AChE) determination, were collected. RDT effects were more evident in fish exposed to the higher concentration of the herbicide. Hematologic alterations appeared only after 96 h exposure, when fish showed an increase in the hematocrit and in the number of both red and white blood cells. After 6h exposure fish showed a transient reduction in superoxide dismutase and catalase activity. RDT also inhibited glutathione-S-transferase, after 6 and 24h of exposure. The reduction in these enzymes is probably related to the occurrence of lipid peroxidation (LPO) in fish exposed to the herbicide for 6h. LPO returned to control levels after 24 and 96 h exposure to RDT, when fish showed an increased activity of glutathione peroxidase. The content of reduced glutathione also increased after 96 h exposure. Thus, after 24 and 96 h the antioxidant defenses were apparently enough to combat ROS, preventing the occurrence of oxidative damage. The exposure to RDT for 96 h led to an inhibition of AChE in brain and muscle at rates which may not be considered a life-threatening situation. PMID:20684975

  3. 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. PMID:26526348

  4. Effect of C-547 (a novel acetylcholinesterase inhibitor) on AChE activity in striated and heart muscles

    Říčný, Jan; Nikolsky, E. E.; Vyskočil, František; Soukup, Tomáš

    Les Arcs : EWCBR, 2008. s. 77-77. [European winter conference on brain research /28./. 08.03.2008-15.03.2008, Les Arcs] R&D Projects: GA ČR(CZ) GA304/05/0327; GA AV ČR(CZ) IAA5011411 Grant ostatní: Myores(XE) 511978 Institutional research plan: CEZ:AV0Z50110509 Source of funding: R - rámcový projekt EK Keywords : spo2 * acetylcholinesterase inhibitors * 6-methyluracil derivatives * skeletal muscles Subject RIV: ED - Physiology

  5. Effect of C-547 (a novel acetylcholinesterase inhibitor) on AChE activity in striated and heart muscles

    Říčný, Jan; Nikolsky, E. E.; Petrov, K. A.; Vyskočil, František; Soukup, Tomáš

    Fyziologický ústav AV ČR, v. v. i.. Roč. 57, č. 2 (2008), 29P-29P ISSN 0862-8408. [Fyziologické dny /84./. 06.02.2008-08.02.2008, Martin] R&D Projects: GA ČR(CZ) GA304/05/0327; GA AV ČR(CZ) IAA5011411 Grant ostatní: Myores(XE) 511978 Institutional research plan: CEZ:AV0Z50110509 Source of funding: R - rámcový projekt EK Keywords : cpo1 * acetylcholinesterase inhibitors * 6-methyluracil derivatives * skeletal muscles Subject RIV: FH - Neurology

  6. Effect of C-547 (a novel acetylcholinesterase inhibitor) on AChE activity in striated and heart muscles

    Říčný, Jan; Nikolsky, E. E.; Petrov, K. A.; Vyskočil, František; Soukup, Tomáš

    Martin : Univerzita Komenského, 2008. s. 111-111. [Fyziologické dny /84./. 06.02.2008-08.02.2008, Martin] R&D Projects: GA ČR(CZ) GA304/05/0327; GA AV ČR(CZ) IAA5011411 Grant ostatní: Myores(XE) 511978 Institutional research plan: CEZ:AV0Z50110509 Source of funding: R - rámcový projekt EK Keywords : spo2 * skeletal muscles * acetylcholinesterase * heart Subject RIV: FH - Neurology

  7. In vivo effects of metals on the acetylcholinesterase activity of the Perna perna mussel’s digestive gland

    Afonso Celso Dias Bainy; Marisa Helena Gennari de Medeiros; Paolo Di Mascio; Eduardo Alves de Almeida

    2006-01-01

    It has been demonstrated that the enzyme acetylcholinesterase (AChE) is strongly inhibited by organophosphate and carbamate pesticides, and also by metals. However, recent reports indicate that some metals can activate AChE during acute exposure. In this work, we were interested in evaluating the effect of trace metal exposure (12, 24, 72 and 120 h) on the AChE activity of Perna perna mussel’s digestive gland. Mussels exposed to Fe or Cu showed no changes in AChE activity during the whole per...

  8. An Expedient Synthesis, Acetylcholinesterase Inhibitory Activity, and Molecular Modeling Study of Highly Functionalized Hexahydro-1,6-naphthyridines

    Almansour, Abdulrahman I.; Raju Suresh Kumar; Natarajan Arumugam; Alireza Basiri; Yalda Kia; Mohamed Ashraf Ali

    2015-01-01

    A series of hexahydro-1,6-naphthyridines were synthesized in good yields by the reaction of 3,5-bis[(E)-arylmethylidene]tetrahydro-4(1H)-pyridinones with cyanoacetamide in the presence of sodium ethoxide under simple mixing at ambient temperature for 6–10 minutes and were assayed for their acetylcholinesterase (AChE) inhibitory activity using colorimetric Ellman’s method. Compound 4e with methoxy substituent at ortho-position of the phenyl rings displayed the maximum inhibitory activity with ...

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

    Gotkine Marc; Rozenstein Leah; Einstein Ofira; Abramsky Oded; Argov Zohar; Rosenmann Hanna

    2013-01-01

    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-...

  10. Pressure-induced molten globule state of human acetylcholinesterase: structural and dynamical changes monitored by neutron scattering.

    Marion, Jérémie; Trovaslet, Marie; N. Martinez; Masson, Patrick; Schweins, R.; Nachon, Florian; Trapp, M; Peters, Judith

    2015-01-01

    We used small-angle neutron scattering (SANS) to study the effects of high hydrostatic pressure on the structure of human acetylcholinesterase (hAChE). At atmospheric pressure, our SANS results obtained on D11 at ILL (Grenoble, France) give a radius of gyration close to that calculated for a mixture of monomers, dimers and tetramers of the enzyme, suggesting a good agreement between hAChE crystal structure and its conformation in solution. Applying high pressure to the sample we found a globa...

  11. Investigation of non-cholinergic acetylcholinesterase, and related peptides in an in vitro preparation of the substantia nigra

    Whyte, Kathryn Antonia.; Greenfield, Susan.; Susan Greenfield

    2001-01-01

    The primary role of acetylcholinesterase (AChE) is hydrolysis of acetylcholine (ACh). However, observations by numerous groups have suggested that AChE may have non-cholinergic functions. Furthermore, developmental roles for AChE and its related enzyme, butyrylcholinesterase (BuChE), which is also capable of ACh hydrolysis, have been postulated. One line of evidence to support a non-cholinergic role for AChE is the apparent disparity in several brain areas between the distribu...

  12. Regional variation in expression of acetylcholinesterase mRNA in adult rat brain analyzed by in situ hybridization.

    Hammond, P; Rao, R; Koenigsberger, C; Brimijoin, S

    1994-01-01

    To investigate the molecular basis of regional variation in expression of brain acetylcholinesterase (AChE; EC 3.1.1.7), steady-state levels of AChE activity and mRNA were examined. Relative AChE activity in Triton extracts from six areas of the rat brain varied as follows: cortex < cerebellum < medulla < pons-midbrain < thalamus < striatum. In contralateral samples from the same brains, AChE mRNA was assessed by Northern blotting with random-primed 32P-labeled cDNA. The regional abundance of...

  13. Short- and long-term influences of calcitonin gene-related peptide on the synthesis of acetylcholinesterase in mammalian myotubes

    da Costa, Valter Luiz; Lapa, Antonio José; Godinho, Rosely O.

    2001-01-01

    The present study analyses the short- (15 min – 2 h) and long-term (24 – 48 h) influences of calcitonin gene-related peptide (CGRP) on acetylcholinesterase (AChE) expression in the rat cultured skeletal muscle and the signal transduction events underlying CGRP actions.To assess the effect of CGRP on AChE synthesis, myotubes were pre-exposed to the irreversible AChE inhibitor diisopropyl fluorophosphate (DFP) and treated with CGRP or forskolin, an adenylyl cyclase (AC) activator. Treatment of ...

  14. An Acetylcholinesterase Antibody-Based Quartz Crystal Microbalance for the Rapid Identification of Spinal Ventral and Dorsal Roots

    Tao Sui; Yingbin Ge; Wujun Liu; Zhao, Zongbao K.; Ning Zhang; Xiaojian Cao

    2013-01-01

    Differences in the levels of acetylcholinesterase (AChE) in ventral and dorsal spinal roots can be used to differentiate the spinal nerves. Although many methods are available to assay AChE, a rapid and sensitive method has not been previously developed. Here, we describe an antibody-based quartz crystal microbalance (QCM) assay and its application for the quantification of AChE in the solutions of ventral and dorsal spinal roots. The frequency variation of the QCM device corresponds to the l...

  15. Plasma protein thiols, ceruloplasmin, C-reactive protein and red blood cell acetylcholinesterase in patients undergoing intrauterine insemination

    Krishnananda Prabhu; Pratap Kumar; Satish Kumar Adiga; Anjali Rao; Anupama Lanka; Jaipal Singh

    2009-01-01

    Objective: To estimate acetylcholinesterase (AChE), protein thiols (PT), ceruloplasmin (CP) and C-reactive proteins (CRPs) to assess any change in their levels following intrauterine insemination (IUI). Materials and Methods: Forty-two patients aged 31 ± 4.65 years (mean ± SD) with primary infertility selected for IUI. All of them had induced ovulation with clomiphene citrate 50 mg from day 2 to day 6. After taking the consent, 2 ml of blood was withdrawn before and after 24 h of IUI for bio...

  16. 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.

  17. 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 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. PMID:27121169

  18. 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.

  19. 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.

  20. Distribution of 125I-neurotensin binding sites in human forebrain: Comparison with the localization of acetylcholinesterase

    The distribution of 125I-neurotensin binding sites was compared with that of acetylcholinesterase reactivity in the human basal forebrain by using combined light microscopic radioautography/histochemistry. High 125I-neurotensin binding densities were observed in the bed nucleus of the stria terminalis, islands of Calleja, claustrum, olfactory tubercle, and central nucleus of the amygdala; lower levels were seen in the caudate, putamen, medial septum, diagonal band nucleus, and nucleus basalis of Meynert. Adjacent sections processed for cholinesterase histochemistry demonstrated a regional overlap between the distribution of labeled neurotensin binding sites and that of intense acetylcholinesterase staining in all of the above regions, except in the bed nucleus of the stria terminalis, claustrum, and central amygdaloid nucleus, where dense 125I-neurotensin labeling was detected over areas containing only weak to moderate cholinesterase staining. At higher magnification, 125I-neurotensin-labeled binding sites in the islands of Calleja, supraoptic nucleus of the hypothalamus, medial septum, diagonal band nucleus, and nucleus basalis of Meynert were selectively associated with neuronal perikarya found to be cholinesterase-positive in adjacent sections. Moderate 125I-neurotensin binding was also apparent over the cholinesterase-reactive neuropil of these latter three regions. These data suggest that neurotensin (NT) may directly influence the activity of magnocellular cholinergic neurons in the human basal forebrain, and may be involved in the physiopathology of dementing disorders such as Alzheimer's disease, in which these neurons have been shown to be affected

  1. Anti-acetylcholinesterase and Antioxidant Activity of Essential Oils from Hedychium gardnerianum Sheppard ex Ker-Gawl

    José Silvino Rosa

    2012-03-01

    Full Text Available Acetylcholinesterase inhibition, antioxidant and cytotoxic activities of Hedychium gardnerianum leaf essential oils from S. Miguel Island were determined. All the oils inhibited acetylcholinesterase, with IC50 values of approximately 1 mg/mL, showing no statistical differences between collection sites. Three oils presented mixed inhibition, whilst one was almost truly competitive. This activity can be attributed to the presence of sesquiterpenes, which constituted more than 60% of the composition of the oils. Regarding the antioxidant activity as measured by the DPPH method, all the oils presented activities similar to reference compounds, although with statistical differences between collection sites. Cytotoxicity measured using Artemia salina classified these oils as moderately toxic, with LC50 values ranging from 300 to 500 µg/mL. These results indicate a possible application of these oils in aromatherapy as coadjuvants in the treatment of cognitive diseases such as Alzheimer, since they may contribute to increase acetylcholine in cholinergic neurons and simultaneously fight deleterious oxidations responsible by neurological degeneration.

  2. Motional heterogeneity in human acetylcholinesterase revealed by a non-Gaussian model for elastic incoherent neutron scattering

    We study the dynamical transition of human acetylcholinesterase by analyzing elastic neutron scattering data with a simulation gauged analytical model that goes beyond the standard Gaussian approximation for the elastic incoherent structure factor [G. R. Kneller and K. Hinsen, J. Chem. Phys. 131, 045104 (2009)]. The model exploits the whole available momentum transfer range in the experimental data and yields not only a neutron-weighted average of the atomic mean square position fluctuations, but also an estimation for their distribution. Applied to the neutron scattering data from human acetylcholinesterase, it reveals a strong increase of the motional heterogeneity at the two transition temperatures T = 150 K and T = 220 K, respectively, which can be located with less ambiguity than with the Gaussian model. We find that the first transition is essentially characterized by a change in the form of the elastic scattering profile and the second by a homogeneous increase of all motional amplitudes. These results are in agreement with previous combined experimental and simulation studies of protein dynamics, which attribute the first transition to an onset of methyl rotations and the second to more unspecific diffusion processes involving large amplitude motions. (authors)

  3. 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

  4. 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

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

    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 IC50 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 [IC50(AChE) = 0.214 μM; IC50(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

  7. 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. PMID:27337188

  8. Measurement of acetylcholinesterase (AChE) activity in living brain by positron emission tomography (PET)

    Central cholinergic neuronal system has been known to be related to learning and memory, and its deficit is found in the brain of Alzheimer's disease (AD) and other degenerative disorders. Postmortem studies have shown that acetylcholinesterase (AChE), one of biochemical markers of central cholinergic nerve system, is consistently reduced in the cerebral cortex of patients with Alzheimer's disease (AD). Non-invasive mapping and/or measuring AChE activity in the living brain by positron emission tomography (PET) would be a useful tool for assessment of cholinergic dysfunction in AD and other disorders, and provide a direct method for validation of therapeutic efficacy of drugs, AChE inhibitors. We have challenged to measure AChE activity using tracers of substrate type, radiolabelled acetylcholine analogs, which are lipophilic enough to go across blood brain barrier and are metabolically trapped by AChE in the brain. The analogs designed, N-methylpiperidyl esters, were evaluated in terms of their metabolic rate and specificity against AChE. Studies examining the response to AChE activity showed metabolic accumulation of some analogs responded well to changes in cortical AChE activity in an animal model of AD. The study was further applied to living human by PET using [11C]N-methylpiperidyl-4-acetate (MP4A), which was chosen on the basis of its reactivity and specificity suitable for the human cortical AChE. Regional cerebral metabolic rate of MP4A reflecting AChE activity was quantitatively determined using three compartment model analysis of dynamic PET data and the arterial input function obtained by TLC-radioluminography or plasma samples. The kinetic analyses showed that AChE activities estimated were well agree with those of postmortem examination in cerebral cortices and thalamus in healthy subjects, and that there was significant reduction of cortical AChE activity in patients with AD. The results suggest feasibility of the present method for assessing ACh

  9. Is it possible to reverse aged acetylcholinesterase inhibited by organophosphorus compounds? Insight from the theoretical study.

    An, Yun; Zhu, Yali; Yao, Yuan; Liu, Junjun

    2016-04-14

    The main treatment for organophosphorus (OP) compound poisoning in clinics is to restore the activity of acetylcholinesterase (AChE) through oxime-induced reactivation of the phosphorylated OP-AChE adduct. It suffers from a competitive and irreversible aging reaction of the phosphorylated OP-AChE adduct, resulting in permanent inactivity of AChE. However, it was recently reported that N-methyl-2-methoxypyridinium species can act as methylating agents to methylate the methyl methane-phosphonate monoanion, in which the reaction mimics the reverse of the aging reaction of the phosphorylated OP-AChE adduct. If the aging reaction could be really reversed, the efficiency for the OP detoxification should be significantly improved, bringing up the possibility to develop an agent to reverse the aging process of the phosphorylated OP-AChE adduct. However, such a reaction with the N-methyl-2-methoxypyridinium species in the enzyme is still not reported so far. It is of great interest to know whether or not this reaction is observable in the enzyme, and more importantly, if it turns out to be not observable in the enzyme, why such a reaction proceeds quickly in aqueous solution but not in the enzyme. In the present study, we performed DFT calculations and quantum mechanical/molecular mechanical (QM/MM) calculations to reveal the fundamental mechanism for the methylation of both the methyl methane-phosphonate monoanion and the aged sarin-AChE adduct by N-methyl-2-methoxypyridinium species, respectively. The obtained results support the SN2 reaction mechanism, not the stepwise mechanism, for the methylation of the methyl methane-phosphonate monoanion by 9 reported N-methyl-2-methoxypyridinium compounds. The calculated free energy barriers are in good agreement with the experimental data. The methylation of the aged sarin-AChE adduct by one N-methyl-2-methoxypyridinium compound (labeled as compound 2) also employs the SN2 reaction mechanism with an extremely high free energy

  10. Effects of oximes on muscle force and acetylcholinesterase activity in isolated mouse hemidiaphragms exposed to paraoxon

    Toxicity of organophosphates (OP) is caused by inhibition of acetylcholinesterase (AChE), resulting in accumulation of acetylcholine. While cholinolytics such as atropine are able to counteract muscarinic symptoms, they are unable to restore the impaired neuromuscular transmission (NMT). Here, oximes as potential reactivators of inhibited AChE may be effective. Until now, no unequivocal relation between oxime-induced increase in muscle force and reactivation has been demonstrated. To address this issue the isolated circumfused mouse hemidiaphragm was used as an experimental model. The muscle force generation upon tetanic stimuli was recorded during AChE inhibition by 1 μM paraoxon and after a wash-out period in the presence of obidoxime, pralidoxime and the experimental oximes HI 6, and HLoe 7, 10 μM each. At the end of the experiments AChE activity was determined in the diaphragm homogenates by a radiometric assay. At 50-Hz stimulation, recovery was complete with obidoxime, nearly complete with HLoe 7 but incomplete with HI 6 and pralidoxime. Only with obidoxime a significant increase in AChE activity was found. An increase of AChE to 10% of normal was sufficient to allow normal muscle force generation. When paraoxon was still present, obidoxime and HLoe 7 were effective at 0.1 μM paraoxon, but failed so at paraoxon >1 μM. The data show different effectiveness of the oximes investigated in reactivation of muscle AChE and recovery of NMT after inhibition by paraoxon. Although an increase in muscle force by the oximes was accompanied by a measurable increase in AChE activity only in the case of obidoxime, the plot of muscle force against AChE activity as well as lacking evidence for a direct effect and adaptive processes indicate that reactivation of the enzyme is the main mechanism of NMT recovery. In agreement, in presence of AChE inhibitory concentrations of paraoxon during reactivation a reduced effectiveness of oximes was found

  11. 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. PMID:27337188

  12. In vitro oxime reactivation of red blood cell acetylcholinesterase inhibited by methyl-paraoxon.

    Petroianu, G A; Arafat, K; Nurulain, S M; Kuca, K; Kassa, J

    2007-01-01

    Oximes are cholinesterase reactivators of use in poisoning with organophosphorus ester enzyme inhibitors. Pralidoxime (PRX) is the oxime used in the United States. Clinical experience with pralidoxime (and other oximes) is disappointing and the routine use has been questioned. Furthermore oximes are not equally effective against all existent enzyme inhibitors. There is a clear demand for 'broad spectrum' cholinesterase reactivators with a higher efficacy than those clinically available. To meet this need over the years new reactivators of cholinesterase of potential clinical utility have been developed. The purpose of the study was to quantify 'in vitro' the extent of protection conferred by available (pralidoxime and methoxime) and experimental (K-27, K-33 and K-48) oximes, using methyl-paraoxon (methyl-POX) as an esterase inhibitor and to compare the results with those previously obtained using paraoxon (POX) as an inhibitor. Red blood cell (RBC) acetylcholinesterase (AChE) activities in whole blood were measured photometrically in the presence of different methyl-POX concentrations and IC(50) values calculated. Determinations were repeated in the presence of increasing oxime concentrations. The IC(50) of methyl-POX (59 nm) increased with the oxime concentration in a linear manner. The calculated IC(50) values were plotted against the oxime concentrations to obtain an IC(50) shift curve. The slope of the shift curve (tg alpha) was used to quantify the magnitude of the protective effect (nm IC(50) increase per microm reactivator). Based on our determinations the new K-series of reactivators is superior to pralidoxime (tg alpha = 1.9) and methoxime (tg alpha = 0.7), K-27 and K-48 being the outstanding compounds with a tg alpha value of 10 (nm IC(50) increase per microm reactivator), which is approximately five times the reactivator ability of PRX. The tg alpha value determined for K-33 was 6.3. The ranking of reactivator potencies of the examined oximes determined

  13. 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.

  14. Acetylcholinesterase capillary enzyme reactor for screening and characterization of selective inhibitors.

    da Silva, Joyce Izidoro; de Moraes, Marcela Cristina; Vieira, Lucas Campos Curcino; Corrêa, Arlene Gonçalves; Cass, Quezia Bezerra; Cardoso, Carmen Lucia

    2013-01-25

    The aim of the present work is to report on the optimized preparation of capillary enzyme reactors (ICERs) based on acetylcholinesterase (AChE, EC 3.1.1.7), for the screening of selective inhibitors. The AChE-ICERs were prepared by using the homobifunctional linker glutaraldehyde through Schiff base linkage. The enzyme was anchored onto a modified fused silica capillary and employed as an LC biochromatography column for online studies, with UV-vis detection. Not only did the tailored AChE-ICER result in maintenance of the activity of the immobilized enzyme, but it also significantly improved the stability of the enzyme in the presence of organic solvents. In addition, the kinetic studies demonstrated that the enzyme retained its activity with high stability, preserving its initial activity over 10months. The absence of non-specific matrix interactions, immediate recovery of the enzymatic activity, and short analysis time were the main advantages of this AChE-ICER. The use of AChE-ICER in the ligands recognition assay was validated by evaluation of four known reversible inhibitors (galanthamine, tacrine, propidium, and rivastigmine), and the same order of inhibitory potencies described in the literature was found. The immobilized enzyme was utilized in the screening of 21 coumarin derivatives. In this library, two new potent inhibitors were identified: coumarins 20 (IC(50) 17.14±3.50μM) and 21 (IC(50) 6.35±1.20μM), which were compared to the standard galanthamine (IC(50) 12.68±2.40μM). Considering the high inhibitory activities of these compounds, with respect to the AChE-ICER, the mechanism of action was investigated. Both coumarins 20 and 21 exhibited a competitive mechanism of action, furnishing K(i) values of 8.04±0.18 and 2.67±0.18μM, respectively. The results revealed that the AChE-ICER developed herein represents a useful tool for the biological screening of inhibitor candidates and evaluation of action mechanism. PMID:22391555

  15. Subchronic atrazine exposure changes defensive behaviour profile and disrupts brain acetylcholinesterase activity of zebrafish.

    Schmidel, Ademir J; Assmann, Karla L; Werlang, Chariane C; Bertoncello, Kanandra T; Francescon, Francini; Rambo, Cassiano L; Beltrame, Gabriela M; Calegari, Daiane; Batista, Cibele B; Blaser, Rachel E; Roman Júnior, Walter A; Conterato, Greicy M M; Piato, Angelo L; Zanatta, Leila; Magro, Jacir Dal; Rosemberg, Denis B

    2014-01-01

    Animal behaviour is the interaction between environment and an individual organism, which also can be influenced by its neighbours. Variations in environmental conditions, as those caused by contaminants, may lead to neurochemical impairments altering the pattern of the behavioural repertoire of the species. Atrazine (ATZ) is an herbicide widely used in agriculture that is frequently detected in surface water, affecting non-target species. The zebrafish is a valuable model organism to assess behavioural and neurochemical effects of different contaminants since it presents a robust behavioural repertoire and also all major neurotransmitter systems described for mammalian species. The goal of this study was to evaluate the effects of subchronic ATZ exposure in defensive behaviours of zebrafish (shoaling, thigmotaxis, and depth preference) using the split depth tank. Furthermore, to investigate a putative role of cholinergic signalling on ATZ-mediated effects, we tested whether this herbicide alters acetylcholinesterase (AChE) activity in brain and muscle preparations. Fish were exposed to ATZ for 14days and the following groups were tested: control (0.2% acetone) and ATZ (10 and 1000μg/L). The behaviour of four animals in the same tank was recorded for 6min and biological samples were prepared. Our results showed that 1000μg/L ATZ significantly increased the inter-fish distance, as well as the nearest and farthest neighbour distances. This group also presented an increase in the shoal area with decreased social interaction. No significant differences were detected for the number of animals in the shallow area, latency to enter the shallow and time spent in shallow and deep areas of the apparatus, but the ATZ 1000 group spent significantly more time near the walls. Although ATZ did not affect muscular AChE, it significantly reduced AChE activity in brain. Exposure to 10μg/L ATZ did not affect behaviour or AChE activity. These data suggest that ATZ impairs defensive

  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. 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.

  18. Anti-acetylcholinesterase and Antioxidant Activities of Inhaled Juniper Oil on Amyloid Beta (1-42)-Induced Oxidative Stress in the Rat Hippocampus.

    Cioanca, Oana; Hancianu, Monica; Mihasan, Marius; Hritcu, Lucian

    2015-05-01

    Juniper volatile oil is extracted from Juniperus communis L., of the Cupressaceae family, also known as common juniper. Also, in aromatherapy the juniper volatile oil is used against anxiety, nervous tension and stress-related conditions. In the present study, we identified the effects of the juniper volatile oil on amyloid beta (1-42)-induced oxidative stress in the rat hippocampus. Rats received a single intracerebroventricular injection of amyloid beta (1-42) (400 pmol/rat) and then were exposed to juniper volatile oil (200 μl, either 1 or 3 %) for controlled 60 min period, daily, for 21 continuous days. Also, the antioxidant activity in the hippocampus was assessed using superoxide dismutase, glutathione peroxidase and catalase specific activities, the total content of the reduced glutathione, protein carbonyl and malondialdehyde levels. Additionally, the acetylcholinesterase activity in the hippocampus was assessed. The amyloid beta (1-42)-treated rats exhibited the following: increase of the acetylcholinesterase, superoxide dismutase and catalase specific activities, decrease of glutathione peroxidase specific activity and the total content of the reduced glutathione along with an elevation of malondialdehyde and protein carbonyl levels. Inhalation of the juniper volatile oil significantly decreases the acetylcholinesterase activity and exhibited antioxidant potential. These findings suggest that the juniper volatile oil may be a potential candidate for the development of therapeutic agents to manage oxidative stress associated with Alzheimer's disease through decreasing the activity of acetylcholinesterase and anti-oxidative mechanism. PMID:25743585

  19. Development of 3D-QSAR model for acetylcholinesterase inhibitors using a combination of fingerprint, molecular docking, and structure-based pharmacophore approaches

    Acetylcholinesterase (AChE), a serine hydrolase vital for regulating the neurotransmitter acetylcholine in animals, has been used as a target for drugs and pesticides. With the increasing availability of AChE crystal structures, with or without ligands bound, structure-based appr...

  20. Development of a 3D-QSAR model for acetylcholinesterase inhibitors using a combination of fingerprint, docking, and structure-based pharmacophore approaches - Conference Abstract

    Acetylcholinesterase (AChE), a serine hydrolase vital for regulating the neurotransmitter acetylcholine in animals, has been used as a target for drugs and pesticides. With the increasing availability of AChE crystal structures, with or without ligands bound, structure-based appr...

  1. A Mechanism-based 3D-QSAR Approach for Classification and Prediction of Acetylcholinesterase Inhibitory Potency of Organophosphate and Carbamate Analogs

    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 understandi...

  2. Malathion Resistance Status and Mutations in Acetylcholinesterase Gene (Ace) in Japanese Encephalitis and Filariasis Vectors from Endemic Area in India.

    Misra, Brij Ranjan; Gore, Milind

    2015-05-01

    Japanese encephalitis (JE) and lymphatic filariasis (LF) are endemic in estern part of Uttar Pradesh in India and transmitted by Culex mosquitoes (Diptera: Culicidae). JE vaccination and mass drug administration for JE and LF management is being undertaken respectively. In addition to this, indoor residual spraying and fogging are used for the control of mosquito vectors. Organophosphate resistance in mosquito is dependent on alteration in acetylcholinesterase (Ace) gene. Hence, it is important to evaluate organophosphate resistance in Culex tritaeniorhynchus Giles (JE vector) and Culex quinquefasciatus Say (LF vector). The current study showed the presence of resistant populations and F331W mutation in Cx. tritaeniorhynchus and G119S mutation in Cx. quinquefasciatus insensitive Ace genes. Resistant populations of these two vectors increase the chances of spreading of resistance in the natural population and may cause failure of intervention programs that include organophosphates against these two vectors in future. PMID:26334819

  3. 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

    majority of pesticides used were WHO class II, classified as moderately hazardous. The mean numbers of personal protective equipment used by farmers were 2.22 (95% CI: 1.89; 2.54). Out of five hygienic practices asked, farmers followed 3.63 (95% CI: 3.40; 3.86) hygienic practices on the average. Farmers...... of healthy individuals. A lower mean haemoglobin-adjusted AChE level was seen among farmers compared to the controls. The use of highly toxic pesticides, inadequate use of personal protective equipment and poor hygienic practices might explain the reason for symptoms of pesticide intoxication and a...... 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...

  4. Acetylcholinesterase Biosensor Based on Poly (diallyldimethylammonium chloride)-multi-walled Carb on Nanotub es-graphene Hybrid Film

    Xia Sun; Zhili Gong; Yaoyao Cao; Xiangyou Wang∗

    2013-01-01

    In this paper, an amperometric acetylcholinesterase (AChE) biosensor for quantitative determi-nation of carbaryl was developed. Firstly, the poly (diallyldimethy-lammonium chloride)-multi-walled carbon nanotubes-graphene hybrid film was modified onto the glassy carbon electrode (GCE) surface, then AChE was immobilized onto the modified GCE to fabricate the AChE biosensor. The morphologies and electrochemistry properties of the prepared AChE biosensor were investigated by using scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. All variables involved in the preparation process and analytical performance of the biosensor were optimized. Based on the inhibition of pesticides on the AChE activity, using carbaryl as model compounds, the biosensor exhibited low detection limit, good reproducibility and high stability in a wide range. Moreover, the biosensor can also be used for direct analysis of practical samples, which would provide a new promising tool for pesticide residues analysis.

  5. In vivo effects of metals on the acetylcholinesterase activity of the Perna perna mussel’s digestive gland

    Afonso Celso Dias Bainy

    2006-03-01

    Full Text Available It has been demonstrated that the enzyme acetylcholinesterase (AChE is strongly inhibited by organophosphate and carbamate pesticides, and also by metals. However, recent reports indicate that some metals can activate AChE during acute exposure. In this work, we were interested in evaluating the effect of trace metal exposure (12, 24, 72 and 120 h on the AChE activity of Perna perna mussel’s digestive gland. Mussels exposed to Fe or Cu showed no changes in AChE activity during the whole period. Mussels exposed to Cd for 72 h or to Pb for 12 hours showed higher AChE activity than the control group. Based on these results, we hypothesize that under acute exposure, metals might interact with acetylcholine receptors, thereby affecting their binding efficiency and leading to a response involving an initial increase in AChE synthesis.

  6. 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. PMID:22617353

  7. A Further Investigation of the Effects of Extremely Low Frequency Magnetic Fields on Alkaline Phosphatase and Acetylcholinesterase.

    Gary Silkstone

    Full Text Available Using a custom build spectrophotometer equipped with Helmholtz coils and designed to study the effects of magnetic fields on enzyme reactions in real-time we have investigated the influence of fields, from 100 μT to 10 mT and at a variety of field frequencies, on the membrane bound enzymes alkaline phosphatase and acetylcholinesterase. We have also employed other methods to apply a magnetic field, e.g. Biostim. In contrast to earlier reports we have been unable to detect any field effects on these enzymes under any field/frequency regime. We discuss possible reasons for the discrepancy between this and earlier work and note the particularly complex influence of small temperature changes that may confound analysis.

  8. 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.

  9. Apparent target size of rat brain benzodiazepine receptor, acetylcholinesterase, and pyruvate kinase is highly influenced by experimental conditions

    Radiation inactivation is a method to determine the apparent target size of molecules. In this report we examined whether radiation inactivation of various enzymes and brain receptors is influenced by the preparation of samples preceding irradiation. The apparent target sizes of endogenous acetylcholinesterase and pyruvate kinase from rat brain and from rabbit muscle and benzodiazepine receptor from rat brain were investigated in some detail. In addition the target sizes of alcohol dehydrogenase (from yeast and horse liver), beta-galactosidase (from Escherichia coli), lactate dehydrogenase (endogenous from rat brain), and 5-HT2 receptors, acetylcholine muscarine receptors, and [35S] butyl bicyclophosphorothionate tertiary binding sites from rat brain were determined. The results show that apparent target sizes are highly influenced by the procedure applied for sample preparation before irradiation. The data indicate that irradiation of frozen whole tissue as opposed to lyophilized tissue or frozen tissue homogenates will estimate the smallest and most relevant functional target size of a receptor or an enzyme

  10. Graveoline Analogs Exhibiting Selective Acetylcholinesterase Inhibitory Activity as Potential Lead Compounds for the Treatment of Alzheimer’s Disease

    Zeng Li

    2016-01-01

    Full Text Available This study designed and synthesized a series of new graveoline analogs on the basis of the structural characteristics of acetylcholinesterase (AChE dual-site inhibitors. The activity of these analogs was also evaluated. Results showed that the synthesized graveoline analogs displayed stronger inhibitory activity against AChE and higher selectivity than butyrylcholine esterase (BuChE (Selectivity Index from 45 to 486. When the two sites in the graveoline parent ring substituting phenyl and amino terminal had six chemical bonds (n = 3 and the terminal amino was piperidine, compound 5c showed the best activity. Furthermore, the mechanism of action and binding mode were explored by enzyme kinetic simulation, molecular docking, and thioflavin T-based fluorometric assay. Cytotoxicity assay showed that the low concentration of the analogs did not affect the viability of the neurocyte SH-SY5Y.

  11. 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.

  12. 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.

  13. 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.

  14. 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. PMID:23210783

  15. 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.

  16. Plasma protein thiols, ceruloplasmin, C-reactive protein and red blood cell acetylcholinesterase in patients undergoing intrauterine insemination

    Krishnananda Prabhu

    2009-01-01

    Full Text Available Objective: To estimate acetylcholinesterase (AChE, protein thiols (PT, ceruloplasmin (CP and C-reactive proteins (CRPs to assess any change in their levels following intrauterine insemination (IUI. Materials and Methods: Forty-two patients aged 31 ± 4.65 years (mean ± SD with primary infertility selected for IUI. All of them had induced ovulation with clomiphene citrate 50 mg from day 2 to day 6. After taking the consent, 2 ml of blood was withdrawn before and after 24 h of IUI for biochemical estimations. Results: We observed a significant decrease in plasma CP, PT and RBC AChE ( P < 0.001 following IUI compared with the respective pre-procedure levels. Highly sensitive CRP showed a marginal increase after IUI. Conclusion: Fluctuations in levels of the above parameters point to their role in the female reproductive system and in the outcome of the IUI.

  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. Behavioral swimming effects and acetylcholinesterase activity changes in Jenynsia multidentata exposed to chlorpyrifos and cypermethrin individually and in mixtures.

    Bonansea, Rocío Inés; Wunderlin, Daniel Alberto; Amé, María Valeria

    2016-07-01

    The pesticides cypermethrin (CYP) and chlorpyrifos (CPF) were found together in water bodies located in agricultural and urban areas. However, the impact to non-target biota from exposure to mixtures has received little attention. In the current study, we evaluated changes in swimming behavior and cholinesterase enzymes activity in Jenynsia multidentata, to investigate the possible effects of these insecticides individually and in mixtures. Moreover, differences between technical and commercial mixtures of the pesticides were evaluated. Females of J. multidentata were exposed over 96-h to CYP (0.04 and 0.4µgL(-1)), CPF (0.4 and 4µgL(-1)), individually and in a technical and commercial mixtures. Swimming behavior was recorded after 24h and 96h of exposure. Also, we measured cholinesterase enzymes activity in brain and muscle after 96h of exposure. Exposure to CYP increased the exploratory activity of J. multidentata in the upper area of the aquarium. Fish exposed to CPF (4µg L(-1)) showed a decrease in swimming activity and an increase in the time spent at the bottom of the aquarium. Interestingly, fish exposed to the technical and commercial mixture of CYP and CPF displayed a different behavior based on the concentration of exposure. Low concentration of pesticides elicited an increase in J. multidentata swimming activity with preference for the upper area of the aquarium, and high concentrations caused decrease in swimming activity with preference for the bottom area of the aquarium. Based on the response of cholinesterase enzymes, acetylcholinesterase in muscle was more sensitive to exposure to CYP, CPF and their mixtures than in brain. A decrease in swimming behavior correlates significantly with the inhibition of acetylcholinesterase activity in muscle of J. multidentata exposed to high concentrations of pesticides. These results draw attention to the need of more studies on the potential ecotoxicological impact of pesticides and its mixtures at

  19. Acetylcholinesterase of Schistosoma mansoni--functional correlates. Contributed in honor of Professor Hans Neurath's 90th birthday.

    Arnon, R; Silman, I; Tarrab-Hazdai, R

    1999-12-01

    Acetylcholinesterase (AChE) is an enzyme broadly distributed in many species, including parasites. It occurs in multiple molecular forms that differ in their quaternary structure and mode of anchoring to the cell surface. This review summarizes biochemical and immunological investigations carried out in our laboratories on AChE of the helmint, Schistosoma mansoni. AChE appears in S. mansoni in two principal molecular forms, both globular, with sedimentation coefficients of approximately 6.5 and 8 S. On the basis of their substrate specificity and sensitivity to inhibitors, both are "true" acetylcholinesterases. Approximately half of the AChE activity of S. mansoni is located on the outer surface of the parasite, attached to the tegumental membrane via a covalently attached glycosylphosphatidylinositol anchor. The remainder is located within the parasite, mainly associated with muscle tissue. Whereas the internal enzyme is most likely involved in termination of neurotransmission at cholinergic synapses, the role of the surface enzyme remains to be established; there are, however, indications that it is involved in signal transduction. The two forms of AChE differ in their heparin-binding properties, only the internal 8 S form of the AChE being retained on a heparin column. The two forms differ also in their immunological specificity, since they are selectively recognized by different monoclonal antibodies. Polyclonal antibodies raised against S. mansoni AChE purified by affinity chromatography are specific for the parasite AChE, reacting with both molecular forms, but do not recognize AChE from other species. They interact with the surface-localized enzyme on the intact organism, and produce almost total complement-dependent killing of the parasite. S. mansoni AChE is thus demonstrated to be a functional protein, involved in multifaceted activities, which can serve as a suitable candidate for diagnostic purposes, vaccine development, and drug design. PMID:10631970

  20. 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

  1. 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

    2016-01-01

    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. PMID:26839417

  2. 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.

  3. 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

    2016-01-01

    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. PMID:26839417

  4. 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.

  5. 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.

  6. Sesquiterpenes and a monoterpenoid with acetylcholinesterase (AchE) inhibitory activity from Valeriana officinalis var. latiofolia in vitro and in vivo.

    Chen, Heng-Wen; He, Xuan-Hui; Yuan, Rong; Wei, Ben-Jun; Chen, Zhong; Dong, Jun-Xing; Wang, Jie

    2016-04-01

    Acetylcholinesterase Inhibitor (AchEI) is the most extensive in all anti-dementia drugs. The extracts and isolated compounds from the Valeriana genus have shown anti-dementia bioactivity. Four new sesquiterpenoids (1-4) and a new monoterpenoid (5) were isolated from the root of Valeriana officinalis var. latiofolia. The acetylcholinesterase (AchE) inhibitory activity of isolates was evaluated by modified Ellman method in vitro. Learning and memory ability of compound 4 on mice was evaluated by the Morris water maze. The contents of acetylcholine (Ach), acetylcholine transferase (ChAT) and AchE in mice brains were determined by colorimetry. The results showed IC50 of compound 4 was 0.161μM in vitro. Compared with the normal group, the learning and memory ability of mice and the contents of Ach and ChAT decreased in model group mice (Penzyme in the cholinergic system. PMID:26976216

  7. Effects of sodium pentobarbital anesthesia and neurotrophic factor on the maintenance of acetylcholinesterase and butyrylcholinesterase in the preganglionically denervated superior cervical ganglion of the cat.

    Koelle, G B; Ruch, G A; Uchida, E

    1983-01-01

    In continuation of a previously reported study, the superior cervical ganglia of cats were preganglionically denervated bilaterally under sodium pentobarbital anesthesia. The following day cats were reanesthetized and infused via the common carotid artery with an aqueous extract of cat brain, spinal cord, and sciatic nerves for periods of 24, 12, 6, and 3 hr, without ligation of the external carotid or lingual arteries as was done previously. Values for acetylcholinesterase and butyrylcholine...

  8. Aqueous Extracts from Tunisian Diplotaxis: Phenol Content, Antioxidant and Anti-Acetylcholinesterase Activities, and Impact of Exposure to Simulated Gastrointestinal Fluids

    Nada Bahloul; Sana Bellili; Smail Aazza; Ameur Chérif; Maria Leonor Faleiro; Maria Dulce Antunes; Maria Graça Miguel; Wissem Mnif

    2016-01-01

    Antioxidants have been considered essential for preventing cell damage by scavenging deleterious free radicals. The consumption of antioxidant-rich plants is associated with a reduced risk of some chronic diseases. This study evaluates the antioxidant and acetylcholinesterase inhibition activities of aqueous extracts obtained from different parts of Diplotaxis simplex and Diplotaxis harra from Tunisia. The study also aimed to investigate the action of simulated gastrointestinal juice on antio...

  9. Altered binding of thioflavin t to the peripheral anionic site of acetylcholinesterase after phosphorylation of the active site by chlorpyrifos oxon or dichlorvos

    The peripheral anionic site of acetylcholinesterase, when occupied by a ligand, is known to modulate reaction rates at the active site of this important enzyme. The current report utilized the peripheral anionic site specific fluorogenic probe thioflavin t to determine if the organophosphates chlorpyrifos oxon and dichlorvos bind to the peripheral anionic site of human recombinant acetylcholinesterase, since certain organophosphates display concentration-dependent kinetics when inhibiting this enzyme. Incubation of 3 nM acetylcholinesterase active sites with 50 nM or 2000 nM inhibitor altered both the Bmax and Kd for thioflavin t binding to the peripheral anionic site. However, these changes resulted from phosphorylation of Ser203 since increasing either inhibitor from 50 nM to 2000 nM did not alter further thioflavin t binding kinetics. Moreover, the organophosphate-induced decrease in Bmax did not represent an actual reduction in binding sites, but instead likely resulted from conformational interactions between the acylation and peripheral anionic sites that led to a decrease in the rigidity of bound thioflavin t. A drop in fluorescence quantum yield, leading to an apparent decrease in Bmax, would accompany the decreased rigidity of bound thioflavin t molecules. The organophosphate-induced alterations in Kd represented changes in binding affinity of thioflavin t, with diethylphosphorylation of Ser203 increasing Kd, and dimethylphosphorylation of Ser203 decreasing Kd. These results indicate that chlorpyrifos oxon and dichlorvos do not bind directly to the peripheral anionic site of acetylcholinesterase, but can affect binding to that site through phosphorylation of Ser203

  10. Aqueous Extracts from Tunisian Diplotaxis: Phenol Content, Antioxidant and Anti-Acetylcholinesterase Activities, and Impact of Exposure to Simulated Gastrointestinal Fluids

    Nada Bahloul

    2016-04-01

    Full Text Available Antioxidants have been considered essential for preventing cell damage by scavenging deleterious free radicals. The consumption of antioxidant-rich plants is associated with a reduced risk of some chronic diseases. This study evaluates the antioxidant and acetylcholinesterase inhibition activities of aqueous extracts obtained from different parts of Diplotaxis simplex and Diplotaxis harra from Tunisia. The study also aimed to investigate the action of simulated gastrointestinal juice on antioxidant activities of both extracts. The total phenolic, flavone and flavonol, and flavanone and dihydroflavonol contents were determined by Folin–Ciocalteau, aluminum chloride and 2,4-dinitrophenylhydrazine colorimetric methods, respectively. The metal ion chelating activity, acetylcholinesterase inhibition capacity, and free radical scavenging potential of the extracts towards ABTS (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid, DPPH (2,2-diphenyl-1-picrylhydrazyl, hydroxyl, superoxide and nitric oxide were also evaluated. The action of simulated gastro-intestinal fluids on the flavone and flavonol content and total antioxidant activity of the flower extracts was surveyed. Extracts from the seeds and flowers of D. simplex and D. harra displayed the highest amounts of phenols (2691.7 and 2694.5 mg Caffeic Acid Equivalent (CAE/100 mg; 3433.4 and 2647.2 mg CAE/100 mg, respectively and flavonols/flavones (2144.4 and 2061.1 mg Rutin Equivalent (RE/100 g; 1922.6 and 1461.1 mg RE/100 g, respectively. The flower and seed extracts exhibited the highest rates of antioxidant and acetylcholinesterase inhibition activities. A decrease in the flavonoid content and antioxidant activity was observed after extract exposure to simulated saliva. Antioxidant and acetylcholinesterase inhibition activities were noted to depend on plant species and plant parts. In vitro gastrointestinal digestion is useful in assessing the bio-accessibility of compounds with

  11. Aqueous Extracts from Tunisian Diplotaxis: Phenol Content, Antioxidant and Anti-Acetylcholinesterase Activities, and Impact of Exposure to Simulated Gastrointestinal Fluids.

    Bahloul, Nada; Bellili, Sana; Aazza, Smail; Chérif, Ameur; Faleiro, Maria Leonor; Antunes, Maria Dulce; Miguel, Maria Graça; Mnif, Wissem

    2016-01-01

    Antioxidants have been considered essential for preventing cell damage by scavenging deleterious free radicals. The consumption of antioxidant-rich plants is associated with a reduced risk of some chronic diseases. This study evaluates the antioxidant and acetylcholinesterase inhibition activities of aqueous extracts obtained from different parts of Diplotaxis simplex and Diplotaxis harra from Tunisia. The study also aimed to investigate the action of simulated gastrointestinal juice on antioxidant activities of both extracts. The total phenolic, flavone and flavonol, and flavanone and dihydroflavonol contents were determined by Folin-Ciocalteau, aluminum chloride and 2,4-dinitrophenylhydrazine colorimetric methods, respectively. The metal ion chelating activity, acetylcholinesterase inhibition capacity, and free radical scavenging potential of the extracts towards ABTS (2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid), DPPH (2,2-diphenyl-1-picrylhydrazyl), hydroxyl, superoxide and nitric oxide were also evaluated. The action of simulated gastro-intestinal fluids on the flavone and flavonol content and total antioxidant activity of the flower extracts was surveyed. Extracts from the seeds and flowers of D. simplex and D. harra displayed the highest amounts of phenols (2691.7 and 2694.5 mg Caffeic Acid Equivalent (CAE)/100 mg; 3433.4 and 2647.2 mg CAE/100 mg, respectively) and flavonols/flavones (2144.4 and 2061.1 mg Rutin Equivalent (RE)/100 g; 1922.6 and 1461.1 mg RE/100 g, respectively). The flower and seed extracts exhibited the highest rates of antioxidant and acetylcholinesterase inhibition activities. A decrease in the flavonoid content and antioxidant activity was observed after extract exposure to simulated saliva. Antioxidant and acetylcholinesterase inhibition activities were noted to depend on plant species and plant parts. In vitro gastrointestinal digestion is useful in assessing the bio-accessibility of compounds with biological activities from

  12. No Evidence to Suggest that the Use of Acetylcholinesterase Inhibitors Confounds the Results of Two Blood-Based Biomarker Studies in Alzheimer's Disease

    Chiam, Justin Tao Wen; Lunnon, Katie; Voyle, Nicola; Proitsi, Petroula; Coppola, Giovanni; Geschwind, Daniel,; Nelson, Sally; Johnston, Caroline; Soininen, Hilkka; Kłoszewska, Iwona; Mecocci, Patrizia; Tsolakik, Magda; Vellas, Bruno; Hodges, Angela; Lovestone, Simon

    2015-01-01

    Background: There is an urgent need to discover Alzheimer's disease (AD) biomarkers that are both easily measured and reliable. Research into blood-based biomarkers for AD using transcriptomics and proteomics has been an attractive and promising area of research. However, to date researchers have not looked into the possibility of AD medication being a confounding factor in these studies. Objective: This study explored whether acetylcholinesterase inhibitors (AChEIs), the main class of AD med...

  13. In vitro characterization of pralidoxime transport and acetylcholinesterase reactivation across MDCK cells and stem cell-derived human brain microvascular endothelial cells (BC1-hBMECs)

    Gallagher, Erin; Minn, IL; Chambers, Janice E.; Searson, Peter C.

    2016-01-01

    Background Current therapies for organophosphate poisoning involve administration of oximes, such as pralidoxime (2-PAM), that reactivate the enzyme acetylcholinesterase. Studies in animal models have shown a low concentration in the brain following systemic injection. Methods To assess 2-PAM transport, we studied transwell permeability in three Madin-Darby canine kidney (MDCKII) cell lines and stem cell-derived human brain microvascular endothelial cells (BC1-hBMECs). To determine whether 2-...

  14. Regulation of the NMDA Receptor-mediated Synaptic Response by Acetylcholinesterase Inhibitors and its Impairment in an Animal Model of Alzheimer’s Disease

    Chen, Guojun; Chen, Paul; Tan, Huibing; Ma, Da; Dou, Fei; FENG, JIAN; Yan, Zhen

    2007-01-01

    The cholinergic system is crucial for cognitive processes and the deficient acetylcholine (ACh) function has been implicated in Alzheimer’s disease (AD). Inhibitors of acetylcholinesterase (AChE), which act to enhance cholinergic function by prolonging the action of endogenously released ACh, have been used as the major therapy of AD. To understand the functional roles of cholinergic enhancement in prefrontal cortex (PFC), a key brain region for cognition, we examined the impact of AChE inhib...

  15. 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.

  16. In situ monitoring of myenteric neuron activity using acetylcholinesterase-modified AlGaN/GaN solution-gate field-effect transistors.

    Müntze, Gesche Mareike; Pouokam, Ervice; Steidle, Julia; Schäfer, Wladimir; Sasse, Alexander; Röth, Kai; Diener, Martin; Eickhoff, Martin

    2016-03-15

    The response characteristics of acetylcholinesterase-modified AlGaN/GaN solution-gate field-effect transistors (AcFETs) are quantitatively analyzed by means of a kinetic model. The characterization shows that the covalent enzyme immobilization process yields reproducible AcFET characteristics with a Michaelis constant KM of (122 ± 4) μM for the immobilized enzyme layer. The increase of KM by a factor of 2.4 during the first four measurement cycles is attributed to partial denaturation of the enzyme. The AcFETs were used to record the release of acetylcholine (ACh) by neuronal tissue cultivated on the gate area upon stimulation by rising the extracellular K(+) concentration. The neuronal tissue constituted of isolated myenteric neurons from four to 12 days old Wistar rats, or sections from the muscularis propria containing the myenteric plexus from adult rats. For both cases the AcFET response was demonstrated to be related to the activity of the immobilized acetylcholinesterase using the reversible acetylcholinesterase blocker donepezil. A concentration response curve of this blocking agent revealed a half maximal inhibitory concentration of 40 nM which is comparable to values measured by complementary in vitro methods. PMID:26547432

  17. Acetylcholinesterase activity in the terrestrial snail Xeropicta derbentina transplanted in apple orchards with different pesticide management strategies

    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.

  18. 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.

  19. 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; Linusson, Anna; Ekström, Fredrik J.

    2016-01-01

    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. PMID:27140636

  20. 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. PMID:25351962

  1. 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.

  2. Acetylcholinesterase biosensor for inhibitor measurements based on glassy carbon electrode modified with carbon black and pillar[5]arene.

    Shamagsumova, Rezeda V; Shurpik, Dmitry N; Padnya, Pavel L; Stoikov, Ivan I; Evtugyn, Gennady A

    2015-11-01

    New acetylcholinesterase (AChE) biosensor based on unsubstituted pillar[5]arene (P[5]A) as electron mediator was developed and successfully used for highly sensitive detection of organophosphate and carbamate pesticides. The AChE from electric eel was immobilized by carbodiimide binding on carbon black (CB) placed on glassy carbon electrode. The working potential of 200mV was obtained in chronoamperometric mode with the measurement time of 180 s providing best inter-biosensors precision of the results. The AChE biosensor developed made it possible to detect 1×10(-11)-1×10(-6) M of malaoxon, 1×10(-8)-7×10(-6) M of methyl-paraoxon, 1×10(-10)-2×10(-6) M of carbofuran and 7×10(-9)-1×10(-5) M of aldicarb with 10 min incubation. The limits of detection were 4×10(-12), 5×10(-9), 2×10(-11) and 6×10(-10) M, respectively. The AChE biosensor was tested in the analysis of pesticide residuals in spiked samples of peanut and beetroot. The protecting effect of P[5]A derivative bearing quaternary ammonia groups on malaoxon inhibition was shown. PMID:26452862

  3. 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. PMID:26948151

  4. Acetylcholinesterase and carbonic anhydrase inhibitory properties of novel urea and sulfamide derivatives incorporating dopaminergic 2-aminotetralin scaffolds.

    Özgeriş, Bünyamin; Göksu, Süleyman; Polat Köse, Leyla; Gülçin, İlhami; Salmas, Ramin Ekhteiari; Durdagi, Serdar; Tümer, Ferhan; Supuran, Claudiu T

    2016-05-15

    In the present study a series of urea and sulfamide compounds incorporating the tetralin scaffolds were synthesized and evaluated for their acetylcholinesterase (AChE), human carbonic anhydrase (CA, EC 4.2.1.1) isoenzyme I, and II (hCA I and hCA II) inhibitory properties. The urea and their sulfamide analogs were synthesized from the reactions of 2-aminotetralins with N,N-dimethylcarbamoyl chloride and N,N-dimethylsulfamoyl chloride, followed by conversion to the corresponding phenols via O-demethylation with BBr3. The novel urea and sulfamide derivatives were tested for inhibition of hCA I, II and AChE enzymes. These derivatives exhibited excellent inhibitory effects, in the low nanomolar range, with Ki values of 2.61-3.69nM against hCA I, 1.64-2.80nM against hCA II, and in the range of 0.45-1.74nM against AChE. In silico techniques such as, atomistic molecular dynamics (MD) and molecular docking simulations, were used to understand the scenario of the inhibition mechanism upon approaching of the ligands into the active site of the target enzymes. In light of the experimental and computational results, crucial amino acids playing a role in the stabilization of the enzyme-inhibitor adducts were identified. PMID:27068142

  5. Acetylcholinesterase(AChE)-catalyzed hydrolysis of long-chain thiocholine esters:shift to a new chemical mechanism

    The kinetic and chemical mechanisms of AChE-catalyzed hydrolysis of short-chain thiocholine esters are relatively well documented. Up to propanoylthiocholine (PrTCh) the chemical mechanism is general acid-base catalysis by the active site catalytic triad. The chemical mechanism for the enzyme-catalyzed butyrylthio-choline(BuTCh) hydrolysis shifts to a parallel mechanism in which general base catalysis by E199 of direct water attack to the carbonyl carbon of the substrate. (Selwood, T., et al. J. Am. Chem. Soc. 1993, 115, 10477-10482) The long chain thiocholine esters such as hexanoylthiocholine (HexTCh), heptanoylthiocholine (HepTCh), and octanoylthiocholine (OcTCh) are hydrolyzed by electric eel acetylcholinesterase (AChE). The kinetic parameters are determined to show that these compounds have a lower Michaelis constant than BuTCh and the pH-Rate profile showed that the mechanism is similar to that of BuTCh hydrolysis. The solvent isotope effect and proton inventory of AChE-catalyzed hydrolysis of HexTCh showed that one proton transfer is involved in the transition state of the acylation stage. The relationship between the dipole moment and the Michaelis constant of the long chain thiocholine esters showed that the dipole moment is the most important factor for the binding of a substrate to the enzyme active site

  6. 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. PMID:27140636

  7. Pre- and post-treatment effect of physostigmine on soman-inhibited human erythrocyte and muscle acetylcholinesterase in vitro

    Standard treatment of organophosphorus (OP) poisoning includes administration of an antimuscarinic (e.g., atropine) and of an oxime-based reactivator. However, successful oxime treatment in soman poisoning is limited due to rapid aging of phosphylated acetylcholinesterase (AChE). Hence, the inability of standard treatment procedures to counteract the effects of soman poisoning resulted in the search for alternative strategies. Recently, results of an in vivo guinea pig study indicated a therapeutic effect of physostigmine given after soman. The present study was performed to investigate a possible pre- and post-treatment effect of physostigmine on soman-inhibited human AChE given at different time intervals before or after perfusion with soman by using a well-established dynamically working in vitro model for real-time analysis of erythrocyte and muscle AChE. The major findings were that prophylactic physostigmine prevented complete inhibition of AChE by soman and resulted in partial spontaneous recovery of the enzyme by decarbamylation. Physostigmine given as post-treatment resulted in a time-dependent reduction of the protection from soman inhibition and recovery of AChE. Hence, these date indicate that physostigmine given after soman does not protect AChE from irreversible inhibition by the OP and that the observed therapeutic effect of physostigmine in nerve agent poisoning in vivo is probably due to other factors.

  8. Coamplification of human acetylcholinesterase and butyrylcholinesterase genes in blood cells: Correlation with various leukemias and abnormal megakaryocytopoiesis

    To study the yet unknown role of the ubiquitous family of cholinesterases (ChoEases) in developing blood cells, the recently isolated cDNAs encoding human acetylcholinesterase and butyrylcholinesterase were used in blot hybridization with peripheral blood DNA from various leukemic patients. Hybridization signals and modified restriction patterns were observed with both cDNA probes in 4 of the 16 leukemia DNA preparations examined. These reflected the amplification of the corresponding AcCho-Ease and BtChoEase genes (ACHE and CHE) and alteration in their structure. Parallel analysis of 30 control samples revealed nonpolymorphic, much weaker hybridization signals for each of the probes. In view of previous reports on the effect of acetylcholine analogs and ChoEase inhibitors in the induction of megakaryocytopoiesis and production of platelets in the mouse. The authors further searched for such phenomena in nonleukemic patients with platelet production disorders. Amplifications of both ACHE and CHE genes were found in 2 of the 4 patients so far examined. Pronounced coamplification of these two related but distinct genes in correlation with pathological production of blood cells suggests a functional role for members of the ChoEase family in megakaryocytopoiesis and raises the question whether the coamplification of these genes could be casually involved in the etiology of hemocytopoietic disorders

  9. Acetylcholinesterase(AChE)-catalyzed hydrolysis of long-chain thiocholine esters:shift to a new chemical mechanism

    Jung, Dai Il; Shin, Young Ju [Donga Univ., Busan (Korea, Republic of); Lee, Eun Seok; Lee, Bong Ho [Hanbat National Univ., Daejon (Korea, Republic of); Moon, Tae Sung; Yoon, Chang No [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

    2003-01-01

    The kinetic and chemical mechanisms of AChE-catalyzed hydrolysis of short-chain thiocholine esters are relatively well documented. Up to propanoylthiocholine (PrTCh) the chemical mechanism is general acid-base catalysis by the active site catalytic triad. The chemical mechanism for the enzyme-catalyzed butyrylthio-choline(BuTCh) hydrolysis shifts to a parallel mechanism in which general base catalysis by E199 of direct water attack to the carbonyl carbon of the substrate. (Selwood, T., et al. J. Am. Chem. Soc. 1993, 115, 10477-10482) The long chain thiocholine esters such as hexanoylthiocholine (HexTCh), heptanoylthiocholine (HepTCh), and octanoylthiocholine (OcTCh) are hydrolyzed by electric eel acetylcholinesterase (AChE). The kinetic parameters are determined to show that these compounds have a lower Michaelis constant than BuTCh and the pH-Rate profile showed that the mechanism is similar to that of BuTCh hydrolysis. The solvent isotope effect and proton inventory of AChE-catalyzed hydrolysis of HexTCh showed that one proton transfer is involved in the transition state of the acylation stage. The relationship between the dipole moment and the Michaelis constant of the long chain thiocholine esters showed that the dipole moment is the most important factor for the binding of a substrate to the enzyme active site.

  10. Development of a biosensing system for tacrine based on nitrogen-doped graphene quantum dots and acetylcholinesterase.

    Benítez-Martínez, S; Caballero-Díaz, E; Valcárcel, M

    2016-04-25

    This work presents a novel fluorescent sensor for the determination of tacrine by combining the magnificent fluorescence properties of nitrogen-doped graphene quantum dots (N-GQDs) with the high potential of acetylcholinesterase (AChE) enzyme for screening its inhibitors. Tacrine was the first drug approved for Alzheimer's disease and it is currently being used in several therapeutic treatments given its activity as a reversible inhibitor of AChE. The principle of the developed biosensor relies on the fact that the native fluorescence of the synthesized N-GQDs is quenched by interaction with enzymatic reaction products, and the inclusion of tacrine in assay solution results in the gradual recovery of the original fluorescence in an inhibitor concentration-dependent manner. While N-GQD fluorescence was not directly affected by tacrine, the inclusion of an AChE based-enzymatic system allowed for its determination with a detection limit (S/N = 3) of 1.22 μM. This biosensor was demonstrated to be simple, rapid and reproducible (%RSD 4.87, n = 7) for analysis of tacrine in aqueous solutions. PMID:27055393

  11. In Vitro Ability of Currently Available Oximes to Reactivate Organophosphate Pesticide-Inhibited Human Acetylcholinesterase and Butyrylcholinesterase

    Kamil Musilek

    2011-03-01

    Full Text Available We have in vitro tested the ability of common, commercially available, cholinesterase reactivators (pralidoxime, obidoxime, methoxime, trimedoxime and HI-6 to reactivate human acetylcholinesterase (AChE, inhibited by five structurally different organophosphate pesticides and inhibitors (paraoxon, dichlorvos, DFP, leptophos-oxon and methamidophos. We also tested reactivation of human butyrylcholinesterase (BChE with the aim of finding a potent oxime, suitable to serve as a “pseudocatalytic” bioscavenger in combination with this enzyme. Such a combination could allow an increase of prophylactic and therapeutic efficacy of the administered enzyme. According to our results, the best broad-spectrum AChE reactivators were trimedoxime and obidoxime in the case of paraoxon, leptophos-oxon, and methamidophos-inhibited AChE. Methamidophos and leptophos-oxon were quite easily reactivatable by all tested reactivators. In the case of methamidophos-inhibited AChE, the lower oxime concentration (10−5 M had higher reactivation ability than the 10−4 M concentration. Therefore, we evaluated the reactivation ability of obidoxime in a concentration range of 10−3–10−7 M. The reactivation of methamidophos-inhibited AChE with different obidoxime concentrations resulted in a bell shaped curve with maximum reactivation at 10−5 M. In the case of BChE, no reactivator exceeded 15% reactivation ability and therefore none of the oximes can be recommended as a candidate for “pseudocatalytic” bioscavengers with BChE.

  12. Highly sensitive electrochemiluminescenc assay of acetylcholinesterase activity based on dual biomarkers using Pd-Au nanowires as immobilization platform.

    Ye, Cui; Wang, Min-Qiang; Zhong, Xia; Chen, Shihong; Chai, Yaqin; Yuan, Ruo

    2016-05-15

    One-dimensional Pd-Au nanowires (Pd-Au NWs) were prepared and applied to fabricate an electrochemiluminescence (ECL) biosensor for the detection of acetylcholinesterase (AChE) activity. Compared with single-component of Pd or Au, the bimetallic nanocomposite of Pd-Au NWs offers a larger surface area for the immobilization of enzyme, and displays superior electrocatalytic activity and efficient electron transport capacity. In the presence of AChE and choline oxidase (ChOx), acetylcholine (ATCl) is hydrolyzed by AChE to generate thiocholine, then thiocholine is catalyzed by ChOx to produce H2O2 in situ, which serves as the coreactant to effectively enhance the ECL intensity in luminol-ECL system. The detection principle is based on the inhibited AChE and reactivated AChE as dual biomarkers, in which AChE was inhibited by organophosphorus (OP) agents, and then reactivated by obidoxime. Such dual biomarkers method can achieve credible evaluation for AChE activity via providing AChE activity before and after reactivation. The liner range for AChE activity detection was from 0.025 U L(-1) to 25 KU L(-1) with a low detection limit down to 0.0083 U L(-1). PMID:26686921

  13. Silibinin inhibits acetylcholinesterase activity and amyloid β peptide aggregation: a dual-target drug for the treatment of Alzheimer's disease.

    Duan, Songwei; Guan, Xiaoyin; Lin, Runxuan; Liu, Xincheng; Yan, Ying; Lin, Ruibang; Zhang, Tianqi; Chen, Xueman; Huang, Jiaqi; Sun, Xicui; Li, Qingqing; Fang, Shaoliang; Xu, Jun; Yao, Zhibin; Gu, Huaiyu

    2015-05-01

    Alzheimer's disease (AD) is characterized by amyloid β (Aβ) peptide aggregation and cholinergic neurodegeneration. Therefore, in this paper, we examined silibinin, a flavonoid extracted from Silybum marianum, to determine its potential as a dual inhibitor of acetylcholinesterase (AChE) and Aβ peptide aggregation for AD treatment. To achieve this, we used molecular docking and molecular dynamics simulations to examine the affinity of silibinin with Aβ and AChE in silico. Next, we used circular dichroism and transmission electron microscopy to study the anti-Aβ aggregation capability of silibinin in vitro. Moreover, a Morris Water Maze test, enzyme-linked immunosorbent assay, immunohistochemistry, 5-bromo-2-deoxyuridine double labeling, and a gene gun experiment were performed on silibinin-treated APP/PS1 transgenic mice. In molecular dynamics simulations, silibinin interacted with Aβ and AChE to form different stable complexes. After the administration of silibinin, AChE activity and Aβ aggregations were down-regulated, and the quantity of AChE also decreased. In addition, silibinin-treated APP/PS1 transgenic mice had greater scores in the Morris Water Maze. Moreover, silibinin could increase the number of newly generated microglia, astrocytes, neurons, and neuronal precursor cells. Taken together, these data suggest that silibinin could act as a dual inhibitor of AChE and Aβ peptide aggregation, therefore suggesting a therapeutic strategy for AD treatment. PMID:25771396

  14. Acetylcholinesterase-Fc Fusion Protein (AChE-Fc): A Novel Potential Organophosphate Bioscavenger with Extended Plasma Half-Life.

    Noy-Porat, Tal; Cohen, Ofer; Ehrlich, Sharon; Epstein, Eyal; Alcalay, Ron; Mazor, Ohad

    2015-08-19

    Acetylcholinesterase (AChE) is the physiological target of organophosphate nerve agent compounds. Currently, the development of a formulation for prophylactic administration of cholinesterases as bioscavengers in established risk situations of exposure to nerve agents is the incentive for many efforts. While cholinesterase bioscavengers were found to be highly effective in conferring protection against nerve agent exposure in animal models, their therapeutic use is complicated by short circulatory residence time. To create a bioscavenger with prolonged plasma half-life, compatible with biotechnological production and purification, a chimeric recombinant molecule of HuAChE coupled to the Fc region of human IgG1 was designed. The novel fusion protein, expressed in cultured cells under optimized conditions, maintains its full enzymatic activity, at levels similar to those of the recombinant AChE enzyme. Thus, this novel fusion product retained its binding affinity toward BW284c5 and propidium, and its bioscavenging reactivity toward the organophosphate-AChE inhibitors sarin and VX. Furthermore, when administered to mice, AChE-Fc exhibits exceptional circulatory residence longevity (MRT of 6000 min), superior to any other known cholinesterase-based recombinant bioscavengers. Owing to its optimized pharmacokinetic performance, high reactivity toward nerve agents, and ease of production, AChE-Fc emerges as a promising next-generation organophosphate bioscavenger. PMID:26121420

  15. Rescue and Stabilization of Acetylcholinesterase in Skeletal Muscle by N-terminal Peptides Derived from the Noncatalytic Subunits.

    Ruiz, Carlos A; Rossi, Susana G; Rotundo, Richard L

    2015-08-21

    The vast majority of newly synthesized acetylcholinesterase (AChE) molecules do not assemble into catalytically active oligomeric forms and are rapidly degraded intracellularly by the endoplasmic reticulum-associated protein degradation pathway. We have previously shown that AChE in skeletal muscle is regulated in part post-translationally by the availability of the noncatalytic subunit collagen Q, and others have shown that expression of a 17-amino acid N-terminal proline-rich attachment domain of collagen Q is sufficient to promote AChE tetramerization in cells producing AChE. In this study we show that muscle cells, or cell lines expressing AChE catalytic subunits, incubated with synthetic proline-rich attachment domain peptides containing the endoplasmic reticulum retrieval sequence KDEL take up and retrogradely transport them to the endoplasmic reticulum network where they induce assembly of AChE tetramers. The peptides act to enhance AChE folding thereby rescuing them from reticulum degradation. This enhanced folding efficiency occurs in the presence of inhibitors of protein synthesis and in turn increases total cell-associated AChE activity and active tetramer secretion. Pulse-chase studies of isotopically labeled AChE molecules show that the enzyme is rescued from intracellular degradation. These studies provide a mechanistic explanation for the large scale intracellular degradation of AChE previously observed and indicate that simple peptides alone can increase the production and secretion of this critical synaptic enzyme in muscle tissue. PMID:26139603

  16. The Nature of Activated Non-classical Hydrogen Bonds: A Case Study on Acetylcholinesterase-Ligand Complexes.

    Berg, Lotta; Mishra, Brijesh Kumar; Andersson, C David; Ekström, Fredrik; Linusson, Anna

    2016-02-01

    Molecular recognition events in biological systems are driven by non-covalent interactions between interacting species. Here, we have studied hydrogen bonds of the CH⋅⋅⋅Y type involving electron-deficient CH donors using dispersion-corrected density functional theory (DFT) calculations applied to acetylcholinesterase-ligand complexes. The strengths of CH⋅⋅⋅Y interactions activated by a proximal cation were considerably strong; comparable to or greater than those of classical hydrogen bonds. Significant differences in the energetic components compared to classical hydrogen bonds and non-activated CH⋅⋅⋅Y interactions were observed. Comparison between DFT and molecular mechanics calculations showed that common force fields could not reproduce the interaction energy values of the studied hydrogen bonds. The presented results highlight the importance of considering CH⋅⋅⋅Y interactions when analysing protein-ligand complexes, call for a review of current force fields, and opens up possibilities for the development of improved design tools for drug discovery. PMID:26751405

  17. Potential use of acetylcholinesterase, glutathione-S-transferase and metallothionein for assessment of contaminated sediment in tropical chironomid, Chironomus javanus.

    Somparn, A; Iwai, C B; Noller, B

    2015-11-01

    Heavy metals and organophosphorus insecticide is known to act as disruptors for the enzyme system, leading to physiologic disorders. The present study was conducted to investigate the potential use of these enzymes as biomarkers in assessment of contaminated sediments on tropical chironomid species. Acetylcholinesterase (AChE), glutathione-S-transferase (GST) and metallothionein (MT) activity was measured in the fourth-instar chironomid larvae, Chironomus javanus, Kieffer, after either 48-hr or 96-hr exposure to organophosphorus insecticide, chlorpyrifos (0.01- 0.25 mg kg(-1)) or heavy metal cadmium (0.1-25 mg kg(-1)). Exposure to chlorpyrifos (0.01 mg kg(-1)) at 48 and 96 hr significantly of AChE activity (64.2%-85.9%) and induced GST activity (33.9-63.8%) when compared with control (P GST activity (11.7-40%) and MT level (9.0%-70.5%) when compared with control (P impact of enzyme activity on chlorpyrifos and cadmium contamination. Activity of AChE, GST and MT could serve as potential biomarkers for assessment and biomonitoring the effects of insecticide and heavy metal contamination in tropical aquatic ecosystems. PMID:26688973

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

    Johannes Van Staden

    2010-10-01

    Full Text Available 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 extractTM showed potent activity against the RT enzyme. Nine mixtures (Imbiza ephuzwato, Umpatisa inkosi, African potato extractTM, 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.

  19. 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. PMID:26447952

  20. 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.

  1. 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. PMID:25978134

  2. 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.

  3. Fucoxanthin, a Marine Carotenoid, Reverses Scopolamine-Induced Cognitive Impairments in Mice and Inhibits Acetylcholinesterase in Vitro

    Lin, Jiajia; Huang, Ling; Yu, Jie; Xiang, Siying; Wang, Jialing; Zhang, Jinrong; Yan, Xiaojun; Cui, Wei; He, Shan; Wang, Qinwen

    2016-01-01

    Fucoxanthin, a natural carotenoid abundant in edible brown seaweeds, has been shown to possess anti-cancer, anti-oxidant, anti-obesity and anti-diabetic effects. In this study, we report for the first time that fucoxanthin effectively protects against scopolamine-induced cognitive impairments in mice. In addition, fucoxanthin significantly reversed the scopolamine-induced increase of acetylcholinesterase (AChE) activity and decreased both choline acetyltransferase activity and brain-derived neurotrophic factor (BDNF) expression. Using an in vitro AChE activity assay, we discovered that fucoxanthin directly inhibits AChE with an IC50 value of 81.2 μM. Molecular docking analysis suggests that fucoxanthin likely interacts with the peripheral anionic site within AChE, which is in accordance with enzymatic activity results showing that fucoxanthin inhibits AChE in a non-competitive manner. Based on our current findings, we anticipate that fucoxanthin might exhibit great therapeutic efficacy for the treatment of Alzheimer’s disease by acting on multiple targets, including inhibiting AChE and increasing BDNF expression. PMID:27023569

  4. A Novel Application of Multiscale Entropy in Electroencephalography to Predict the Efficacy of Acetylcholinesterase Inhibitor in Alzheimer's Disease.

    Tsai, Ping-Huang; Chang, Shih-Chieh; Liu, Fang-Chun; Tsao, Jenho; Wang, Yung-Hung; Lo, Men-Tzung

    2015-01-01

    Alzheimer's disease (AD) is the most common form of dementia. According to one hypothesis, AD is caused by the reduced synthesis of the neurotransmitter acetylcholine. Therefore, acetylcholinesterase (AChE) inhibitors are considered to be an effective therapy. For clinicians, however, AChE inhibitors are not a predictable treatment for individual patients. We aimed to disclose the difference by biosignal processing. In this study, we used multiscale entropy (MSE) analysis, which can disclose the embedded information in different time scales, in electroencephalography (EEG), in an attempt to predict the efficacy of AChE inhibitors. Seventeen newly diagnosed AD patients were enrolled, with an initial minimental state examination (MMSE) score of 18.8 ± 4.5. After 12 months of AChE inhibitor therapy, 7 patients were responsive and 10 patients were nonresponsive. The major difference between these two groups is Slope 2 (MSE6 to 20). The area below the receiver operating characteristic (ROC) curve of Slope 2 is 0.871 (95% CI = 0.69-1). The sensitivity is 85.7% and the specificity is 60%, whereas the cut-off value of Slope 2 is -0.024. Therefore, MSE analysis of EEG signals, especially Slope 2, provides a potential tool for predicting the efficacy of AChE inhibitors prior to therapy. PMID:26120358

  5. A Novel Application of Multiscale Entropy in Electroencephalography to Predict the Efficacy of Acetylcholinesterase Inhibitor in Alzheimer’s Disease

    Ping-Huang Tsai

    2015-01-01

    Full Text Available Alzheimer’s disease (AD is the most common form of dementia. According to one hypothesis, AD is caused by the reduced synthesis of the neurotransmitter acetylcholine. Therefore, acetylcholinesterase (AChE inhibitors are considered to be an effective therapy. For clinicians, however, AChE inhibitors are not a predictable treatment for individual patients. We aimed to disclose the difference by biosignal processing. In this study, we used multiscale entropy (MSE analysis, which can disclose the embedded information in different time scales, in electroencephalography (EEG, in an attempt to predict the efficacy of AChE inhibitors. Seventeen newly diagnosed AD patients were enrolled, with an initial minimental state examination (MMSE score of 18.8±4.5. After 12 months of AChE inhibitor therapy, 7 patients were responsive and 10 patients were nonresponsive. The major difference between these two groups is Slope 2 (MSE6 to 20. The area below the receiver operating characteristic (ROC curve of Slope 2 is 0.871 (95% CI = 0.69–1. The sensitivity is 85.7% and the specificity is 60%, whereas the cut-off value of Slope 2 is −0.024. Therefore, MSE analysis of EEG signals, especially Slope 2, provides a potential tool for predicting the efficacy of AChE inhibitors prior to therapy.

  6. [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. PMID:17675917

  7. Reactivation of organophosphate-inhibited human, Cynomolgus monkey, swine and guinea pig acetylcholinesterase by MMB-4: A modified kinetic approach

    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.

  8. Effects of chlorpyrifos ethyl on acetylcholinesterase activity in climbing perch cultured in rice fields in the Mekong Delta, Vietnam.

    Nguyen, Tam Thanh; Berg, Håkan; Nguyen, Hang Thi Thuy; Nguyen, Cong Van

    2015-07-01

    Climbing perch is commonly harvested in rice fields and associated wetlands in the Mekong Delta. Despite its importance in providing food and income to local households, there is little information how this fish species is affected by the high use of pesticides in rice farming. Organophosphate insecticides, such as chlorpyrifos ethyl, which are highly toxic to aquatic organisms, are commonly used in the Mekong Delta. This study shows that the brain acetylcholinesterase (AChE) activity in climbing perch fingerlings cultured in rice fields, was significantly inhibited by a single application of chlorpyrifos ethyl, at doses commonly applied by rice farmers (0.32-0.64 kg/ha). The water concentration of chlorpyrifos ethyl decreased below the detection level within 3 days, but the inhibition of brain AChE activity remained for more than 12 days. In addition, the chlorpyrifos ethyl treatments had a significant impact on the survival and growth rates of climbing perch fingerlings, which were proportional to the exposure levels. The results indicate that the high use of pesticides among rice farmers in the Mekong Delta could have a negative impact on aquatic organisms and fish yields, with implications for the aquatic biodiversity, local people's livelihoods and the aquaculture industry in the Mekong Delta. PMID:25828891

  9. A highly stable minimally processed plant-derived recombinant acetylcholinesterase for nerve agent detection in adverse conditions.

    Rosenberg, Yvonne J; Walker, Jeremy; Jiang, Xiaoming; Donahue, Scott; Robosky, Jason; Sack, Markus; Lees, Jonathan; Urban, Lori

    2015-01-01

    Although recent innovations in transient plant systems have enabled gram quantities of proteins in 1-2 weeks, very few have been translated into applications due to technical challenges and high downstream processing costs. Here we report high-level production, using a Nicotiana benthamiana/p19 system, of an engineered recombinant human acetylcholinesterase (rAChE) that is highly stable in a minimally processed leaf extract. Lyophylized clarified extracts withstand prolonged storage at 70 °C and, upon reconstitution, can be used in several devices to detect organophosphate (OP) nerve agents and pesticides on surfaces ranging from 0 °C to 50 °C. The recent use of sarin in Syria highlights the urgent need for nerve agent detection and countermeasures necessary for preparedness and emergency responses. Bypassing cumbersome and expensive downstream processes has enabled us to fully exploit the speed, low cost and scalability of transient production systems resulting in the first successful implementation of plant-produced rAChE into a commercial biotechnology product. PMID:26268538

  10. Template-Based de Novo Design for Type II Kinase Inhibitors and Its Extented Application to Acetylcholinesterase Inhibitors

    Bo-Han Su

    2013-10-01

    Full Text Available There is a compelling need to discover type II inhibitors targeting the unique DFG-out inactive kinase conformation since they are likely to possess greater potency and selectivity relative to traditional type I inhibitors. Using a known inhibitor, such as a currently available and approved drug or inhibitor, as a template to design new drugs via computational de novo design is helpful when working with known ligand-receptor interactions. This study proposes a new template-based de novo design protocol to discover new inhibitors that preserve and also optimize the binding interactions of the type II kinase template. First, sorafenib (Nexavar® and nilotinib (Tasigna®, two type II inhibitors with different ligand-receptor interactions, were selected as the template compounds. The five-step protocol can reassemble each drug from a large fragment library. Our procedure demonstrates that the selected template compounds can be successfully reassembled while the key ligand-receptor interactions are preserved. Furthermore, to demonstrate that the algorithm is able to construct more potent compounds, we considered kinase inhibitors and other protein dataset, acetylcholinesterase (AChE inhibitors. The de novo optimization was initiated using a template compound possessing a less than optimal activity from a series of aminoisoquinoline and TAK-285 inhibiting type II kinases, and E2020 derivatives inhibiting AChE respectively. Three compounds with greater potency than the template compound were discovered that were also included in the original congeneric series. This template-based lead optimization protocol with the fragment library can help to design compounds with preferred binding interactions of known inhibitors automatically and further optimize the compounds in the binding pockets.

  11. 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.

  12. Larvicidal and acetylcholinesterase inhibitory activities of apiaceae plant essential oils and their constituents against aedes albopictus and formulation development.

    Seo, Seon-Mi; Jung, Chan-Sik; Kang, Jaesoon; Lee, Hyo-Rim; Kim, Sung-Woong; Hyun, Jinho; Park, Il-Kwon

    2015-11-18

    This study evaluated the larvicidal activity of 12 Apiaceae plant essential oils and their components against the Asian tiger mosquito, Aedes albopictus, and the inhibition of acetylcholine esterase with their components. Of the 12 plant essential oils tested, ajowan (Trachyspermum ammi), caraway seed (Carum carvi), carrot seed (Daucus carota), celery (Apium graveolens), cumin (Cuminum cyminum), dill (Anethum graveolens), and parsley (Petroselinum sativum) resulted in >90% larval mortality when used at 0.1 mg/mL. Of the compounds identified, α-phellandrene, α-terpinene, p-cymene, (-)-limonene, (+)-limonene, γ-terpinene, cuminaldehyde, neral, (S)-+-carvone, trans-anethole, thymol, carvacrol, myristicin, apiol, and carotol resulted in >80% larval mortality when used at 0.1 mg/mL. Two days after treatment, 24.69, 3.64, and 12.43% of the original amounts of the celery, cumin, and parsley oils, respectively, remained in the water. Less than 50% of the original amounts of α-phellandrene, 1,8-cineole, terpinen-4-ol, cuminaldehyde, and trans-antheole were detected in the water at 2 days after treatment. Carvacrol, α-pinene, and β-pinene inhibited the activity of Ae. albopictus acetylcholinesterase with IC50 values of 0.057, 0.062, and 0.190 mg/mL, respectively. A spherical microemulsion of parsley essential oil-loaded poly(vinyl alcohol) (PVA) was prepared, and the larvicidal activity of this formulation was shown to be similar to that of parsley oil. PMID:26500081

  13. Effect of Acetylcholinesterase and Butyrylcholinesterase on Intrauterine Insemination, Contribution to Inflammations, Oxidative Stress and Antioxidant Status; A Preliminary Report

    Haghnazari, Lida; Vaisi-Raygani, Asad; Keshvarzi, Farahnaz; Ferdowsi, Farivar; Goodarzi, Massoud; Rahimi, Zohreh; Baniamerian, Hossin; Tavilani, Haidar; Vaisi-Raygani, Hadis; Vaisi-Raygani, Hessam; Pourmotabbed, Tayehbeh

    2016-01-01

    Background: Oxidative stress affects women fertility and influences on the sperm quality by alterating activities of cholinesterases, a molecular marker of stress-related infertility. The aim of the present study was to investigate the role of acetyl-cholinesterase (AChE), butyrylcholinesterase (BuChE) activities and phenotypes in patients with unexplained infertility (idiopathic). It’s possible association with inflammation marker C-reactive protein (CRP) and other oxidative stress markers, i.e. before and after intra uterine insemination (IUI). Methods: In this study, blood samples of 60 patients with unexplained infertility were collected the day before and 24 hr after IUI (between 8 AM and 9 AM after the overnight fasting) and activities of BuChE, AChE, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GpX) and serum levels of thiol proteins (TP), C-reactive protein (CRP), total antioxidant capacity (TAC) were measured. Statistical significance was assumed at pCAT activity between various BuChE (UU and non-UU) phenotypes. However, after IUI, a significant negative correlation between the AChE activity and BuChE activity was found (p=0.045) and the level of RBC AChE activity was significantly reduced (382.4± 163.19 vs. 586.7±384 IU/grHb, p=0.025). Meanwhile, after IUI, the activities of SOD (1568±847.5 IU/grHb vs. 1126±229.3, p=0.031) and CAT (310±53.4 IU/grHb vs. 338±73, p=0.025) were increased. Conclusion: This study suggests that decline in cholinesterases activities may be responsible for stimulation of oxidative stress and inflammation and reduction in fertility rates by IUI. PMID:27478769

  14. Chromogenic platform based on recombinant Drosophila melanogaster acetylcholinesterase for visible unidirectional assay of organophosphate and carbamate insecticide residues

    Highlight: ► A visible chromogenic platform for rapid analysis of OP and CM insecticide residues was developed. ► The assay has the capabilities of both qualitative measurement and quantitative analysis. ► The sensitivity, capabilities of resisting interferences and storage stability were desirable. ► 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 IC50 values against the tested six insecticides (0.06 μg mL−1 of carbofuran, 0.28 μg mL−1 of methomyl, 0.03 μg mL−1 of dichlorvos, 31.6 μg mL−1 of methamidophos, 2.0 μg mL−1 of monocrotophos, 6.3 μg mL−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 10−3 to 101 μg g−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.

  15. 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.

  16. Isolation of endocytic and exocytic populations of coated vesicles from perfused rat liver using an acetylcholinesterase mediated density shift technique

    Rat liver contains endogenous acetylcholinesterase (AChE). The authors have isolated rat liver coated vesicles (CVs) and incubated them with the Karnovsky-Roots reagents and the AChE substrate, acetylthiocholine. A dense iron-copper precipitate is deposited at hydrolysis sites. When the CVs are subjected to sucrose-Ficoll-D20 density gradient ultracentrifugation, the AChE containing CVs are shifted to a denser region of the gradient. The molecular forms of AChE present in the CVs resemble secretory AChE not serum AChE. CVs isolated from perfused liver, treated with diisopropylfluorophosphate (DFP), to inactivate endogenous AChE, and allowed to resynthesize AChE for 30 minutes, contain AChE which is shown to be exocytic. When 125I-insulin and gal-AChE are co-perfused into DFP treated liver for 3 minutes, the CVs isolated and density shifted, approximately 80% of both Gal-AChE and 125I-insulin are in the shifted fraction which also contains approximately 50% of the CVs. Similar experiments have been carried out using 35S-methionine to label newly synthesized secretory proteins. They have measured the diameter of the endocytic and exocytic CVs and have found that the endocytic CVs are significantly larger than the exocytic CVs and more heterogeneous in size. When the cholesterol/phospholipid ratio was compared in both populations, the endocytic CVs had a significantly higher ratio than the exocytic CVs. Finally both populations were subjected to one dimensional and two dimensional SDS gel electrophoresis and were found to be remarkably similar in protein composition

  17. 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

  18. Studies on the effects of some insecticides on the brain acetylcholinesterase activity of Tilapia zilli in two treated tropical rivers

    With a view to controlling onchocerciasis in West Africa, the Marahoue and Black Volta Rivers in Cote d'Ivoire were treated with chlorphoxim and temephos, respectively, at a concentration of 0.5 mg·L-1 per 10 minute application to kill the Simulium larvae. As part of the Onchocerciasis Control Programme, studies were conducted with caged Tilapia zilli to determine the effects of the two larvicides on the fishery resources in the treated rivers. These showed that chlorphoxim inhibits the brain acetylcholinesterase (AChE) activity of the caged T. zilli up to 1 km downstream of the breeding site. The highest level of reduction in AChE activity (32%) was recorded in the caged fish placed near the point of release of the chlorphoxim 24 hours after the river treatment. At 0.5 km downstream of the breeding site, the percentage enzyme reduction was 24%, and at the 1 km point the AChE activity was reduced by 17%. There was no significant reduction (P > 0.05) in the brain enzyme activity of the caged fish placed at a distance of about 3 km downstream of the breeding site. It was further observed that the caged fish had not recovered from the inhibitory effects of the chlorphoxim 48 hours after the river treatment. No evidence of any inhibitory effects on the brain AChE activity of the caged fish was found as a result of temephos treatment of the Black Volta River at any distance from the point of larvicide application. (author). 16 refs, 1 fig., 4 tabs

  19. Molecular docking and 3D-QSAR studies of 2-substituted 1-indanone derivatives as acetylcholinesterase inhibitors

    Liang-liang SHEN; Gui-xia LIU; Yun TANG

    2007-01-01

    Aim: To explore the binding mode of 2-substituted 1-indanone derivatives with acetylcholinesterase (ACHE) and provide hints for the future design of new de- rivatives with higher potency and specificity. Methods: The GOLD-docking con- formations of the compounds in the active site of the enzyme were used in subse- quent studies. The highly reliable and predictive three-dimensional quantitative structure-activity relationship (3D-QSAR) models were achieved by comparative molecular field analysis (CoMFA) and comparative molecular similarity analysis (CoMSIA) methods. The predictive capabilities of the models were validated by an external test set. Moreover, the stabilities of the 3D-QSAR models were veri- fied by the leave-4-out cross-validation method. Results: The CoMFA and CoMSIA models were constructed successfully with a good cross-validated coef- ficient (q2) and a non-cross-validated coefficient (r2). The q2 and r2 obtained from the leave-1-out cross validation method were 0.784 and 0.974 in the CoMFA model and 0.736 and 0.947 in the CoMSIA model, respectively. The coefficient isocontour maps obtained from these models were compatible with the geometrical and physi- cochemical properties of AChE. Conclusion: The contour map demonstrated that the binding affinity could be enhanced when the small protonated nitrogen moi- ety was replaced by a more hydrophobic and bulky group with a highly partial positive charge. The present study provides a better understanding of the inter- action between the inhibitors and ACHE, which is helpful for the discovery of new compounds with more potency and selective activity.

  20. Functional study on the mutations in the silkworm (Bombyx mori) acetylcholinesterase type 1 gene (ace1) and its recombinant proteins.

    Wang, Ju-mei; Wang, Bin-bin; Xie, Yi; Sun, Shan-shan; Gu, Zhi-ya; Ma, Lie; Li, Fan-chi; Zhao, Yi-fan; Yang, Bin; Shen, Wei-de; Li, Bing

    2014-01-01

    The acetylcholinesterase of Lepidoptera insects is encoded by two genes, ace1 and ace2. The expression of the ace1 gene is significantly higher than that of the ace2 gene, and mutations in ace1 are one of the major reasons for pesticide resistance in insects. In order to investigate the effects of the mutations in ace1's characteristic sites on pesticide resistance, we generated mutations for three amino acids using site-directed mutagenesis, which were Ala(GCG)303Ser(TCG), Gly(GGA)329Ala(GCA) and Leu (TCT)554Ser(TTC). The Baculovirus expression system was used for the eukaryotic expression of the wild type ace1 (wace1) and the mutant ace1 (mace1). SDS-PAGE and Western blotting were used to detect the targeting proteins with expected sizeof about 76 kDa. The expression products were purified for the determination of AChE activity and the inhibitory effects of physostigmine and phoxim. We observed no significant differences in the overall activity of the wild type and mutant AChEs. However, with 10 min of physostigmine (10 μM) inhibition, the remaining activity of the wild type AChE was significantly lower than that of the mutant AChE. Ten min inhibition with 33.4 μM phoxim also resulted in significantly lower remaining activity of the wild type AChE than that of the mutant AChE. These results indicated that mutations for the three amino acids reduced the sensitivity of AChE to physostigmine and phoxim, which laid the foundation for future in vivo studies on AChE's roles in pesticide resistance. PMID:24323194