Inhibitory effect of ebselen on cerebral acetylcholinesterase activity in vitro: kinetics and reversibility of inhibition.

Science.gov (United States)

Martini, Franciele; Bruning, César Augusto; Soares, Suelen Mendonca; Nogueira, Cristina Wayne; Zeni, Gilson

2015-01-01

Ebselen is a synthetic organoselenium compound that has been considered a potential pharmacological agent with low toxicity, showing antioxidant, anti-inflammatory and neuroprotective effects. It is bioavailable, blood-brain barrier permeant and safe based on cellular toxicity and Phase I-III clinical trials. There is evidence that ebselen inhibits acetylcholinesterase (AChE) activity, an enzyme that plays a key role in the cholinergic system by hydrolyzing acetylcholine (ACh), in vitro and ex vivo. This system has a well-known relationship with cognitive process, and AChE inhibitors, such as donepezil and galantamine, have been used to treat cognitive deficits, mainly in the Alzheimer's Disease (AD). However, these drugs have poor bioavailability and a number of side effects, including gastrointestinal upsets and hepatotoxicity. In this way, this study aimed to evaluate the effect of ebselen on cerebral AChE activity in vitro and to determine the kinetic profile and the reversibility of inhibition by dialysis. Ebselen inhibited the cerebral AChE activity with an IC50 of 29 µM, similar to IC50 found with pure AChE from electric eel, demonstrating a mixed and reversible inhibition of AChE, since it increased Km and decreased Vmax. The AChE activity was recovered within 60 min of dialysis. Therefore, the use of ebselen as a therapeutic agent for treatment of AD should be considered, although memory behavior tasks are needed to support such hypothesis.

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

OpenAIRE

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...

Acetylcholinesterase Inhibitors (AChEI's for the treatment of visual hallucinations in schizophrenia: A review of the literature

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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.

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

International Nuclear Information System (INIS)

Yang Dongren; Howard, Angela; Bruun, Donald; Ajua-Alemanj, Mispa; Pickart, Cecile; Lein, Pamela J.

2008-01-01

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

Quantitative structure-activity analysis of acetylcholinesterase inhibition by oxono and thiono analogues of organophosphorus compounds. (Reannouncement with new availability information)

Energy Technology Data Exchange (ETDEWEB)

Maxwell, D.M.; Brecht, K.M.

1992-02-01

A comparison of the bimolecular rate constants (ki) for inhibition of electric eel acetylcholinesterase (AChE) by the oxono (i.e., P=O) and thiono (i.e., P=S) analogues of parathion, methylparathion, leptophos, fonofos, sarin, and soman revealed that the oxono/thiono ratios of ki values varied from 14 for soman to 1240 for parathion. Analysis of the relative importance of the dissociation equilibrium constant and the phosphorylation rate constant in producing this variation in ki values indicated that the oxono analogues had phosphorylation rate constant values that varied in a narrow range from 8- to 14-fold greater than their thiono counterparts, while the oxono/thiono ratios for dissociation constants varied widely from 1 for soman to 82 for fonofos. The lower affinities of thiono analogues for AChE probably resulted from differences in the hydrophobic binding of oxono and thiono analogues to the active site of AChE, inasmuch as the hydrophobicities (i.e., octanol/water partition coefficients) of thiono organophosphorus compounds were much greater than the hydrophobicities of their oxono analogues. Quantitative structure-activity analysis indicated that the hydrophobic effects of oxono and thiono moieties correlated with log ki for AChE inhibition to a greater extent (r2 = 0.79) than their electronic effects (r2 equal to or less than 0.48). These observations suggest that the differences in hydrophobicity of oxono and thiono analogues of organophosphorus compounds may be as important as their electronic differences in determining their effectiveness as AChE inhibitors. Acetylcholinesterase, soman (GD), structure-activity analysis inhibition, oxono analogues, thiono analogues.

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

International Nuclear Information System (INIS)

Herkert, N.M.; Schulz, S.; Wille, T.; Thiermann, H.; Hatz, R.A.; Worek, F.

2011-01-01

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.

Dual Inhibition of AChE and BChE with the C-5 Substituted Derivative of Meldrum’s Acid: Synthesis, Structure Elucidation, and Molecular Docking Studies

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Haroon Mehfooz

2017-07-01

Full Text Available Alzheimer’s disease (AD lies in the category of those diseases which are still posing challenges to medicinal chemists, and the search for super-effective drugs for the treatment of AD is a work in progress. The inhibition of cholinesterase is considered a viable strategy to enhance the level of acetylcholine in the brain. The C-5 substituted derivative of Meldrum’s acid was synthesized and screened against acetylcholinesterase (AChE and butyrylcholinesterase (BChE enzyme inhibition activity. The simple and unique structure of synthesized derivative 3 was found to be good for the dual inhibition of both enzymes (AChE and BChE. 2,2-Dimethyl-5-(([2-(trifluoromethyl phenyl]aminomethylidene-1,3-dioxane-4,6-dione (3 showed significant inhibition against AChE, with an IC50 value of 1.13 ± 0.03 µ M (Standard Neostigmine 22.2 ± 3.2 µM, and moderate inhibition against BChE, with an IC50 value of 2.12 ± 1.22 µM (Standard Neostigmine 49.6 ± 6.11 µM. The structural insights reveal that compound 3 possesses intriguing reactive groups, which can potentially evoke the non-covalent interactions and possibly assist by binding in the active site of the target protein. Docking simulations revealed that the compound 3 showed binding inside the active site gorges of both AChE and BChE. An excellent agreement was obtained, as the best docked poses showed important binding features mostly based on interactions due to oxygen atoms and the aromatic moieties of the compound. The docking computations coupled with the experimental findings ascertained that the compound 3 can serve as a scaffold for the dual inhibitors of the human acetylcholine esterases.

Effects of EGCG and Chlorpyrifos on the Mortality, AChE and GSH of Adult Zebrafish: Independent and Combination

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Zhang, Rong; Zhang, Jian; Gao, Qian; Guo, Nichun

2018-01-01

Chlorpyrifos is a neurotoxic agent and also causes oxidative stress in the body. EGCG is a typical strong antioxidant and has been reported to be neuroprotective. Our study investigated the mortality, the activity of acetylcholinesterase (AChE) in the brain and glutathione (GSH) in the liver of the adult Zebrafish in present of Chlorpyrifos and EGCG independent and combination. The results indicated that after the addition of EGCG, the mortality of zebrafish induced by Chlorpyrifos was reduced and the activity of AChE and glutathione (GSH) inhibited by Chlorpyrifos in zebrafish was significantly increased, which demonstrated that EGCG inhibited the toxicity Chlorpyrifos to zebrafish. The inhibition was dependent on the concentration of EGCG and Chlorpyrifos, which was not shown a gradual change trend but a complex situation.

Synthesis, Biological Evaluation, and Docking Studies of Novel Bisquaternary Aldoxime Reactivators on Acetylcholinesterase and Butyrylcholinesterase Inhibited by Paraoxon

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Kamil Kuca

2018-05-01

Full Text Available Nerve agents and oxon forms of organophosphorus pesticides act as strong irreversible inhibitors of two cholinesterases in the human body: acetylcholinesterase (AChE; EC 3.1.1.7 and butyrylcholinesterase (BChE; EC 3.1.1.8, and are therefore highly toxic compounds. For the recovery of inhibited AChE, antidotes from the group of pyridinium or bispyridinium aldoxime reactivators (pralidoxime, obidoxime, HI-6 are used in combination with anticholinergics and anticonvulsives. Therapeutic efficacy of reactivators (called “oximes” depends on their chemical structure and also the type of organophosphorus inhibitor. Three novel oximes (K131, K142, K153 with an oxime group in position four of the pyridinium ring were designed and then tested for their potency to reactivate human (Homo sapiens sapiens AChE (HssACHE and BChE (HssBChE inhibited by the pesticide paraoxon (diethyl 4-nitrophenyl phosphate. According to the obtained results, none of the prepared oximes were able to satisfactorily reactivate paraoxon-inhibited cholinesterases. On the contrary, extraordinary activity of obidoxime in the case of paraoxon-inhibited HssAChE reactivation was confirmed. Additional docking studies pointed to possible explanations for these results.

In Search of an Effective in vivo Reactivator for Organophosphorus Nerve Agent-Inhibited Acetylcholinesterase in the Central Nervous System

Science.gov (United States)

2012-01-01

nerve agents, such as sarin (GB), cyclosarin (GF), and VX, are potent inhibitors of the enzyme cholinesterase (ChE). Their toxic effects are due to...three nerve agents. Keywords: acetylcholinesterase; brain; cholinesterase inhibition; cholinesterase reactivation; cyclosarin; diacetylmonoxime...attributed, at least in part, to nuclophilic impedance [Ekstrom et al., 2006a; b; Hoskovcova et al., 2007]. Other AChE- inhibitors , such as soman, become

Revealing the importance of linkers in K-series oxime reactivators for tabun-inhibited AChE using quantum chemical, docking and SMD studies.

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Ghosh, Shibaji; Chandar, Nellore Bhanu; Jana, Kalyanashis; Ganguly, Bishwajit

2017-08-01

Inhibition of acetylcholinesterase (AChE) with organophosphorus compounds has a detrimental effect on human life. Oxime K203 seems to be one of the promising reactivators for tabun-inhibited AChE than (K027, K127, and K628). These reactivators differ only in the linker units between the two pyridinium rings. The conformational analyses performed with quantum chemical RHF/6-31G* level for K027, K127, K203 and K628 showed that the minimum energy conformers have different orientations of the active and peripheral pyridinium rings for these reactivator molecules. K203 with (-CH 2 -CH=CH-CH 2 -) linker unit possesses more open conformation compared to the other reactivators. Such orientation of K203 experiences favorable interaction with the surrounding residues of catalytic anionic site (CAS) and peripheral anionic site (PAS) of tabun-inhibited AChE. From the steered molecular dynamics simulations, it has been observed that the oxygen atom of the oxime group of K203 reactivator approaches nearest to the P-atom of the SUN203 (3.75 Å) at lower time scales (less than ~1000 ps) as compared to the other reactivators. K203 experiences less number of hydrophobic interaction with the PAS residues which is suggested to be an important factor for the efficient reactivation process. In addition, K203 crates large number of H-bonding with CAS residues SUN203, Phe295, Tyr337, Phe338 and His447. K203 barely changes its conformation during the SMD simulation process and hence the energy penalty to adopt any other conformation is minimal in this case as compared to the other reactivators. The molecular mechanics and Poisson-Boltzmann surface area binding energies obtained for the interaction of K203 inside the gorge of tabun inhibited AChE is substantially higher (-290.2 kcal/mol) than the corresponding K628 reactivator (-260.4 kcal/mol), which also possess unsaturated aromatic linker unit.

Revealing the importance of linkers in K-series oxime reactivators for tabun-inhibited AChE using quantum chemical, docking and SMD studies

Science.gov (United States)

Ghosh, Shibaji; Chandar, Nellore Bhanu; Jana, Kalyanashis; Ganguly, Bishwajit

2017-08-01

Inhibition of acetylcholinesterase (AChE) with organophosphorus compounds has a detrimental effect on human life. Oxime K203 seems to be one of the promising reactivators for tabun-inhibited AChE than (K027, K127, and K628). These reactivators differ only in the linker units between the two pyridinium rings. The conformational analyses performed with quantum chemical RHF/6-31G* level for K027, K127, K203 and K628 showed that the minimum energy conformers have different orientations of the active and peripheral pyridinium rings for these reactivator molecules. K203 with (-CH2-CH=CH-CH2-) linker unit possesses more open conformation compared to the other reactivators. Such orientation of K203 experiences favorable interaction with the surrounding residues of catalytic anionic site (CAS) and peripheral anionic site (PAS) of tabun-inhibited AChE. From the steered molecular dynamics simulations, it has been observed that the oxygen atom of the oxime group of K203 reactivator approaches nearest to the P-atom of the SUN203 (3.75 Å) at lower time scales (less than 1000 ps) as compared to the other reactivators. K203 experiences less number of hydrophobic interaction with the PAS residues which is suggested to be an important factor for the efficient reactivation process. In addition, K203 crates large number of H-bonding with CAS residues SUN203, Phe295, Tyr337, Phe338 and His447. K203 barely changes its conformation during the SMD simulation process and hence the energy penalty to adopt any other conformation is minimal in this case as compared to the other reactivators. The molecular mechanics and Poisson-Boltzmann surface area binding energies obtained for the interaction of K203 inside the gorge of tabun inhibited AChE is substantially higher (-290.2 kcal/mol) than the corresponding K628 reactivator (-260.4 kcal/mol), which also possess unsaturated aromatic linker unit.

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

Directory of Open Access Journals (Sweden)

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.

Stabilizing Acetylcholinesterase on Carbon Electrodes Using Peptide Nanotubes to Produce Effective Biosensors

Science.gov (United States)

2012-03-22

disposable, inhibition 1. Introduction Organophosphates (OPs) are acetyl cholinesterase (AChE) inhibitors with a broad range of potency and toxicity...5 Cholinesterase Biosensors...BIOSENSORS I. Introduction Background Organophosphates (OPs) are acetylcholinesterase (AChE) inhibitors with a broad range of potency and

Chemical composition and acetylcholinesterase inhibitory activity of Artemisia maderaspatana essential oil.

Science.gov (United States)

Jyotshna; Srivastava, Nidhi; Singh, Bhuwanendra; Chanda, Debabrata; Shanker, Karuna

2015-01-01

To date, there are no reports to validate the Indian traditional and folklore claims of Artemisia maderaspatana L. (syn. Grangea maderaspatana L.) (Asteraceae) for the treatment of Alzheimer's disease. The present study characterizes the volatile components (non-polar compounds) of A. maderaspatana and evaluates its acetylcholinesterase inhibition potential. The essential oils (yield 0.06% v/w) were obtained from fresh aerial part of A. maderaspatana. The characterization of volatile components (non-polar compounds) was performed by GC-MS data and with those of reference compounds compiled in the spectral library of in-house database. The in vitro acetylcholinesterase (AChE) inhibition of the volatile organic constituents (VOC's) of A. maderaspatana aerial part was evaluated in varying concentration ranges (0.70-44.75 µg/mL) with Ellman's method. The major components were α-humulene (46.3%), β-caryophyllene (9.3%), α-copaene (8.2%), β-myrcene (4.3%), Z(E)-α-farnesene (3.7%), and calarene (3.5%). Chemical variability among other Artemisia spp. from different climatic regions of India and countries namely Iran and France was observed. The experimental results showed that diverse volatile organic constituents of A. maderaspatana have significant acetylcholinesterase inhibitory activity (an IC50 value of 31.33 ± 1.03 µg/mL). This is the first report on the inhibition of acetylcholinesterase properties of essential oil of A. maderaspatana obtained from fresh aerial part. The present results indicate that essential oil of A. maderaspatana isolated from the northern region of India could inhibit AChE moderately. Therefore, the possibility of novel AChE inhibitors might exist in VOCs of this plant.

Inactivation of acetylcholinesterase by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride.

Science.gov (United States)

Zang, Lun-Yi; Misra, Hara P

2003-12-01

The neurotoxicant 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) has been shown to reversibly inhibit the activity of acetylcholinesterase. The inactivation of the enzyme was detected by monitoring the accumulation of yellow color produced from the reaction between thiocholine and dithiobisnitrobenzoate ion. The kinetic parameter, Km for the substrate (acetylthiocholine), was found to be 0.216 mM and Ki for MPTP inactivation of acetylcholinesterase was found to be 2.14 mM. The inactivation of enzyme by MPTP was found to be dose-dependent. It was found that MPTP is neither a substrate of AChE nor the time-dependent inactivator. The studies of reaction kinetics indicate the inactivation of AChE to be a linear mixed-type inhibition. The dilution assays indicate that MPTP is a reversible inhibitor for AChE. These data suggest that once MPTP enters the basal ganglia of the brain, it can inactivate the acetylcholinesterase enzyme and thereby increase the acetylcholine level in the basal ganglia of brain, leading to potential cell dysfunction. It appears that the nigrostriatal toxicity by MPTP leading to Parkinson's disease-like syndrome may, in part, be mediated via the acetylcholinesterase inactivation.

Acetylcholinesterase inhibition in cognition-relevant brain areas of mice treated with a nootropic Amazonian herbal (Marapuama).

Science.gov (United States)

Figueiró, M; Ilha, J; Pochmann, D; Porciúncula, L O; Xavier, L L; Achaval, M; Nunes, D S; Elisabetsky, E

2010-10-01

The goal of acetylcholinesterase inhibitors (AChEIs) used to treat Alzheimer's patients is an improvement in cholinergic transmission. While currently available AChEIs have limited success, a huge impediment to the development of newer ones is access to the relevant brain areas. Promnesic, anti-amnesic and AChEI properties were identified in a standardized ethanol extract from Ptychopetalum olacoides (POEE), a medicinal plant favored by the elderly in Amazon communities. The purpose of this study was to provide conclusive evidence that orally given POEE induces AChE inhibition in brain areas relevant to cognition. Histochemistry experiments confirmed that the anticholinesterase compound(s) present in POEE are orally bioavailable, inducing meaningful AChE inhibition in the hippocampus CA1 (∼33%) and CA3 (∼20%), and striatum (∼17%). Ellman's colorimetric analysis revealed that G1 and G4 AChE isoforms activities were markedly inhibited (66 and 72%, respectively) in hippocampus and frontal cortex (50 and 63%, respectively), while G4 appeared to be selectively inhibited (72%) in the striatum. Western blotting showed that POEE did not induce significant changes in the AChE immunocontent suggesting that its synthesis is not extensively modified. This study provides definitive proof of meaningful anticholinesterase activity compatible with the observed promnesic and anti-amnesic effects of POEE in mice, reaffirming the potential of this extract for treating neurodegenerative conditions where a hypofunctioning cholinergic neurotransmission is prominent. Adequate assessment of the safety and efficacy of this extract and/or its isolated active compound(s) are warranted. 2010 Elsevier GmbH. All rights reserved.

Screening of acetylcholinesterase inhibitors in snake venom by electrospray mass spectrometry

NARCIS (Netherlands)

Liesener, A.; Perchuc, Anna-Maria; Schöni, Reto; Schebb, Nils Helge; Wilmer, Marianne; Karst, U.

2007-01-01

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

New Acetylcholinesterase Inhibitors for Alzheimer's Disease

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Mona Mehta

2012-01-01

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

The role of the oximes HI-6 and HS-6 inside human acetylcholinesterase inhibited with nerve agents: a computational study.

Science.gov (United States)

Cuya, Teobaldo; Gonçalves, Arlan da Silva; da Silva, Jorge Alberto Valle; Ramalho, Teodorico C; Kuca, Kamil; C C França, Tanos

2017-10-27

The oximes 4-carbamoyl-1-[({2-[(E)-(hydroxyimino) methyl] pyridinium-1-yl} methoxy) methyl] pyridinium (known as HI-6) and 3-carbamoyl-1-[({2-[(E)-(hydroxyimino) methyl] pyridinium-1-yl} methoxy) methyl] pyridinium (known as HS-6) are isomers differing from each other only by the position of the carbamoyl group on the pyridine ring. However, this slight difference was verified to be responsible for big differences in the percentual of reactivation of acetylcholinesterase (AChE) inhibited by the nerve agents tabun, sarin, cyclosarin, and VX. In order to try to find out the reason for this, a computational study involving molecular docking, molecular dynamics, and binding energies calculations, was performed on the binding modes of HI-6 and HS-6 on human AChE (HssAChE) inhibited by those nerve agents.

Comparison of Chlorpyrifos-Oxon and Paraoxon Acetylcholinesterase Inhibition Dynamics: Potential role of a peripheral binding site

Energy Technology Data Exchange (ETDEWEB)

Kousba, Ahmed A.; Sultatos, L G.; Poet, Torka S.; Timchalk, Chuck

2004-08-02

The primary mechanism of action for organophosphorus (OP) insecticides involves the inhibition of acetylcholinesterase (AChE) by oxygenated metabolites (oxons). This inhibition has been attributed to the phosphorylation of the serine hydroxyl group located in the active site of the AChE molecule. The rate of phosphorylation is described by the bimolecular inhibitory rate constant (ki), which has been utilized for quantification of OP inhibitory capacity. It has been previously proposed that a peripheral binding site exists on the AChE molecule, which when occupied, reduces the capacity of additional oxon molecules to phosphorylate the active site. The objective of the current study was to evaluate the interaction of chlorpyrifos oxon (CPO) and paraoxon (PO) with rat brain AChE using a modified Ellman assay in conjunction with a pharmacodynamic model to further assess the dynamics of AChE inhibition and the potential role of a peripheral binding site. The ki for AChE inhibition determined at oxon concentrations of 5 x 10{sup -4} 100 nM were 0.212 and 0.0216 nM-1h-1 for CPO and PO, respectively. The spontaneous reactivation rates of the inhibited AChE for CPO and PO were 0.087 and 0.078 h-1, respectively. In contrast, the ki estimated at a low oxon concentration (1 pM) were {approx} 1,000 and 10,000 -fold higher than those determined at high CPO and PO concentrations, respectively. At these low concentrations, the ki estimates were approximately similar for both CPO and PO (180 and 250 nM-1h-1, respectively). This implies that at low exposure concentrations, both oxons exhibited similar inhibitory potency in contrast to the marked difference exhibited at higher concentrations, which is consistent with the presence of a peripheral binding site on the AChE enzyme. These results support the potential importance of a secondary binding site associated with AChE kinetics, particularly at low environmentally relevant concentrations.

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

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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.

Reactivation of organophosphate-inhibited human, Cynomolgus monkey, swine and guinea pig acetylcholinesterase by MMB-4: A modified kinetic approach

International Nuclear Information System (INIS)

Worek, Franz; Wille, Timo; Aurbek, Nadine; Eyer, Peter; Thiermann, Horst

2010-01-01

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.

Reactivation of organophosphate-inhibited human, Cynomolgus monkey, swine and guinea pig acetylcholinesterase by MMB-4: a modified kinetic approach.

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Worek, Franz; Wille, Timo; Aurbek, Nadine; Eyer, Peter; Thiermann, Horst

2010-12-15

Treatment of poisoning by highly toxic organophosphorus compounds (OP, nerve agents) is a continuous challenge. Standard treatment with atropine and a clinically used oxime, obidoxime or pralidoxime is inadequate against various nerve agents. For ethical reasons testing of oxime efficacy has to be performed in animals. Now, it was tempting to investigate the reactivation kinetics of MMB-4, a candidate oxime to replace pralidoxime, with nerve agent-inhibited acetylcholinesterase (AChE) from human and animal origin in order to provide a kinetic basis for the proper assessment of in vivo data. By applying a modified kinetic approach, allowing the use of necessary high MMB-4 concentrations, it was possible to determine the reactivation constants with sarin-, cyclosarin-, VX-, VR- and tabun-inhibited AChE. MMB-4 exhibited a high reactivity and low affinity towards OP-inhibited AChE, except of tabun-inhibited enzyme where MMB-4 had an extremely low reactivity. Species differences between human and animal AChE were low (Cynomolgus) to moderate (swine, guinea pig). Due to the high reactivity of MMB-4 a rapid reactivation of inhibited AChE can be anticipated at adequate oxime concentrations which are substantially higher compared to HI-6. Additional studies are necessary to determine the in vivo toxicity, tolerability and pharmacokinetics of MMB-4 in humans in order to enable a proper assessment of the value of this oxime as an antidote against nerve agent poisoning. Copyright © 2010 Elsevier Inc. All rights reserved.

Centrally Acting Oximes in Reactivation of Tabun-Phosphoramidated AChE

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Kovarik, Zrinka; Maček, Nikolina; Sit, Rakesh K.; Radić, Zoran; Fokin, Valery V.; Sharpless, K. Barry; Taylor, Palmer

2012-01-01

Organophosphates (OP) inhibit acetylcholinesterase (AChE, E.C.3.1.1.7), both in peripheral tissues and central nervous system (CNS), causing adverse and sometimes fatal effects due to the accumulation of neurotransmitter acetylcholine (ACh). The currently used therapy, focusing on the reactivation of inhibited AChE, is limited to peripheral tissues because commonly used quaternary pyridinium oxime reactivators do not cross the blood brain barrier (BBB) at therapeutically relevant levels. A directed library of thirty uncharged oximes that contain tertiary amine or imidazole protonable functional groups that should cross the BBB as unionized species was tested as tabun-hAChE conjugate reactivators along with three reference oximes: DAM (diacetylmonoxime), MINA (monoisonitrosoacetone), and 2-PAM. The oxime RS150D [N-((1-(3-(2-((hydroxyimino)methyl)-1H-imidazol-1-yl)propyl)-1H-1,2,3-triazol-4-yl)methyl)benzamide] was highlighted as the most promising reactivator of the tabun-hAChE conjugate. We also observed that oximes RS194B [N-(2-(azepan-1-yl)ethyl)-2-(hydroxyimino)acetamide] and RS41A [2-(hydroxyimino)-N-(2-(pyrrolidin-1-yl)ethyl)acetamide], which emerged as lead uncharged reactivators of phosphylated hAChE with other OPs (sarin, cyclosarin and VX), exhibited only moderate reactivation potency for tabun inhibited hAChE. This implies that geometry of oxime access to the phosphorus atom conjugated to the active serine is an important criterion for efficient reactivation, along with the chemical nature of the conjugated moiety: phosphorate, phosphonate, or phosphoramidate. Moreover, modification of the active center through mutagenesis enhances the rates of reactivation. The phosphoramidated-hAChE choline-binding site mutant Y337A showed three-times enhanced reactivation capacity with non-triazole imidazole containing aldoximes (RS113B, RS113A and RS115A) and acetamide derivative (RS194B) than with 2PAM. PMID:22960624

Evaluation of acetylcholinesterase inhibitory activity of Brazilian red macroalgae organic extracts

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Levi P. Machado

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.

Variation of Musca domestica L. acetylcholinesterase in Danish housefly populations

DEFF Research Database (Denmark)

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

2006-01-01

Anti-cholinesterase resistance is in many cases caused by modified acetylcholinesterase (MACE). A comparison was made of toxicological data and AChE activity gathered from 21 field populations and nine laboratory strains of houseflies, Musca domestica L., to elucidate the best way of generating...... data to provide advice for management strategies and gathering information for resistance risk assessment on the organophosphates azamethiphos and dimethoate and the carbamate methomyl, which have been the primary insecticides used against adult houseflies in Denmark. Cluster analysis was performed...... and > 2000 houseflies were assigned to one of three phenotypes based on total acetylcholinesterase activity as well as inhibition by azamethiphos, methomyl or omethoate. A cluster, i.e. a phenotype, with high total AChE activity and high sensitivity to azamethiphos and less sensitivity to inhibition...

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.

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

2009-04-28

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

Acetylcholinesterase inhibition and locomotor function after motor-sensory cortex impact injury.

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Holschneider, Daniel P; Guo, Yumei; Roch, Margareth; Norman, Keith M; Scremin, Oscar U

2011-09-01

Traumatic brain injury (TBI) induces transient or persistent dysfunction of gait and balance. Enhancement of cholinergic transmission has been reported to accelerate recovery of cognitive function after TBI, but the effects of this intervention on locomotor activity remain largely unexplored. The hypothesis that enhancement of cholinergic function by inhibition of acetylcholinesterase (AChE) improves locomotion following TBI was tested in Sprague-Dawley male rats after a unilateral controlled cortical impact (CCI) injury of the motor-sensory cortex. Locomotion was tested by time to fall on the constant speed and accelerating Rotarod, placement errors and time to cross while walking through a horizontal ladder, activity monitoring in the home cages, and rearing behavior. Assessments were performed the 1st and 2nd day and the 1st, 2nd, and 3rd week after TBI. The AChE inhibitor physostigmine hemisulfate (PHY) was administered continuously via osmotic minipumps implanted subcutaneously at the rates of 1.6-12.8 μmol/kg/day. All measures of locomotion were impaired by TBI and recovered to initial levels between 1 and 3 weeks post-TBI, with the exception of the maximum speed achievable on the accelerating Rotarod, as well as rearing in the open field. PHY improved performance in the accelerating Rotarod at 1.6 and 3.2 μmol/kg/day (AChE activity 95 and 78% of control, respectively), however, higher doses induced progressive deterioration. No effect or worsening of outcomes was observed at all PHY doses for home cage activity, rearing, and horizontal ladder walking. Potential benefits of cholinesterase inhibition on locomotor function have to be weighed against the evidence of the narrow range of useful doses.

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

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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.

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

International Nuclear Information System (INIS)

Schallreuter, Karin U.; University of Bradford; Elwary, Souna M.; Parkin, Susan M.; Wood, John M.

2007-01-01

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 -3 M) via a specific EF-hand calcium binding site, whereas acetylcholinesterase (AchE) is not affected. 45 Calcium labelling and computer simulation confirmed the presence of one EF-hand binding site per subunit which is disrupted by H 2 O 2 -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 m 2 surface area with its calcium gradient in the 10 -3 M range, our results implicate calcium-activated BuchE as a major protective mechanism against suicide inhibition of AchE by organophosphates in this non-neuronal tissue

Acute Toxicity of Organophosphorus Compounds in Guinea Pigs Is Sex- and Age-Dependent and Cannot Be Solely Accounted for by Acetylcholinesterase Inhibition

OpenAIRE

Fawcett, William P.; Aracava, Yasco; Adler, Michael; Pereira, Edna F. R.; Albuquerque, Edson X.

2008-01-01

This study was designed to test the hypothesis that the acute toxicity of the nerve agents S-[2-(diisopropylamino)ethyl]-O-ethyl methylphosphonothioate (VX), O-pinacolyl methylphosphonofluoridate (soman), and O-isopropyl methylphosphonofluoridate (sarin) in guinea pigs is age- and sex-dependent and cannot be fully accounted for by the irreversible inhibition of acetylcholinesterase (AChE). The subcutaneous doses of nerve agents needed to decrease 24-h survival of guine...

Acotiamide hydrochloride (Z-338) enhances gastric motility and emptying by inhibiting acetylcholinesterase activity in rats.

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Kawachi, Masanao; Matsunaga, Yugo; Tanaka, Takao; Hori, Yuko; Ito, Katsunori; Nagahama, Kenji; Ozaki, Tomoko; Inoue, Naonori; Toda, Ryoko; Yoshii, Kazuyoshi; Hirayama, Masamichi; Kawabata, Yoshihiro; Takei, Mineo

2011-09-01

In clinical trials, acotiamide hydrochloride (acotiamide: Z-338) has been reported to be useful in the treatment of functional dyspepsia. Here, we investigated the effects of acotiamide on gastric contraction and emptying activities in rats in comparison with itopride hydrochloride (itopride) and mosapride citrate (mosapride). We also examined in vitro the compound's inhibitory effect on acetylcholinesterase (AChE) activity derived from rat stomach. In in vivo studies, acotiamide (30 and 100mg/kg s.c.) and itopride (100mg/kg s.c.) markedly enhanced normal gastric antral motility in rats. In gastric motility dysfunction models, acotiamide (100mg/kg s.c.) and itopride (100mg/kg s.c.) improved both gastric antral hypomotility and the delayed gastric emptying induced by clonidine, an α(2)-adrenoceptor agonist. In contrast, mosapride (10mg/kg s.c.) had no effect on these models. Like the AChE inhibitors itopride (30 mg/kg s.c.) and neostigmine (10 μg/kg s.c.), acotiamide (10mg/kg s.c.) also clearly enhanced gastric body contractions induced by electrical stimulation of the vagus, which were abolished by atropine and hexamethonium, whereas mosapride (3 and 10mg/kg s.c.) did not. In in vitro studies, acotiamide concentration-dependently inhibited rat stomach-derived AChE activity (IC(50)=2.3 μmol/l). In addition, stomach tissue concentrations of acotiamide after administration at 10mg/kg s.c. were sufficient to produce inhibition of AChE activity in rat stomach. These results suggest that acotiamide stimulates gastric motility and improves gastric motility dysfunction in rats by inhibiting AChE activity, and may suggest a role for acotiamide in improving gastric motility dysfunction in patients with functional dyspepsia. Copyright © 2011 Elsevier B.V. All rights reserved.

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

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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.

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

Science.gov (United States)

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.

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

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Yves Bourne

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

New Cinchona Oximes Evaluated as Reactivators of Acetylcholinesterase and Butyrylcholinesterase Inhibited by Organophosphorus Compounds

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Maja Katalinić

2017-07-01

Full Text Available For the last six decades, researchers have been focused on finding efficient reactivators of organophosphorus compound (OP-inhibited acetylcholinesterase (AChE and butyrylcholinesterase (BChE. In this study, we have focused our research on a new oxime scaffold based on the Cinchona structure since it was proven to fit the cholinesterases active site and reversibly inhibit their activity. Three Cinchona oximes (C1, C2, and C3, derivatives of the 9-oxocinchonidine, were synthesized and investigated in reactivation of various OP-inhibited AChE and BChE. As the results showed, the tested oximes were more efficient in the reactivation of BChE and they reactivated enzyme activity to up to 70% with reactivation rates similar to known pyridinium oximes used as antidotes in medical practice today. Furthermore, the oximes showed selectivity towards binding to the BChE active site and the determined enzyme-oxime dissociation constants supported work on the future development of inhibitors in other targeted studies (e.g., in treatment of neurodegenerative disease. Also, we monitored the cytotoxic effect of Cinchona oximes on two cell lines Hep G2 and SH-SY5Y to determine the possible limits for in vivo application. The cytotoxicity results support future studies of these compounds as long as their biological activity is targeted in the lower micromolar range.

Xanthone and Flavone Derivatives as Dual Agents with Acetylcholinesterase Inhibition and Antioxidant Activity as Potential Anti-Alzheimer Agents

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Inês Cruz

2017-01-01

Full Text Available Alzheimer’s disease (AD is a multifactorial neurodegenerative disorder that is associated with the elderly. The current therapy that is used to treat AD is based mainly on the administration of acetylcholinesterase (AChE inhibitors. Due to their low efficacy there is a considerable need for other therapeutic strategies. Considering that the malfunctions of different, but interconnected, biochemical complex pathways play an important role in the pathogenesis of this disease, a promising therapy may consist in administration of drugs that act on more than a target on biochemical scenery of AD. In this work, the synthesis and evaluation of xanthone and flavone derivatives as antioxidants with AChE inhibitory activity were accomplished. Among the obtained compounds, Mannich bases 3 and 14 showed capacity to inhibit AChE and antioxidant property, exerting dual activity. Moreover, for the most promising AChE inhibitors, docking studies on the target have been performed aiming to predict the binding mechanism. The results presented here may help to identify new xanthone and flavone derivatives as dual anti-Alzheimer agents with AChE inhibitory and antioxidant activities.

Discovery of potent and selective acetylcholinesterase (AChE) inhibitors: acacetin 7-O-methyl ether Mannich base derivatives synthesised from easy access natural product naringin.

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Liu, Hao-Ran; Men, Xue; Gao, Xiao-Hui; Liu, Lin-Bo; Fan, Hao-Qun; Xia, Xin-Hua; Wang, Qiu-An

2018-03-01

Naringin, as a component universal existing in the peel of some fruits or medicinal plants, was usually selected as the material to synthesise bioactive derivates since it was easy to gain with low cost. In present investigation, eight new acacetin-7-O-methyl ether Mannich base derivatives (1-8) were synthesised from naringin. The bioactivity evaluation revealed that most of them exhibited moderate or potent acetylcholinesterase (AChE) inhibitory activity. Among them, compound 7 (IC 50 for AChE = 0.82 ± 0.08 μmol•L -1 , IC 50 for BuChE = 46.30 ± 3.26 μmol•L -1 ) showed a potent activity and high selectivity compared with the positive control Rivastigmine (IC 50 for AChE = 10.54 ± 0.86 μmol•L -1 , IC 50 for BuChE = 0.26 ± 0.08 μmol•L -1 ). The kinetic study suggested that compound 7 bind to AChE with mix-type inhibitory profile. Molecular docking study revealed that compound 7 could combine both catalytic active site (CAS) and peripheral active site (PAS) of AChE with four points (Trp84, Trp279, Tyr70 and Phe330), while it could bind with BuChE via only His 20.

Synthesis and Biological Evaluation of Novel Jatrorrhizine Derivatives with Amino Groups Linked at the 3-Position as Inhibitors of Acetylcholinesterase

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Xiaofei Jiang

2017-01-01

Full Text Available Jatrorrhizine was considered as one of the active constituents of Coptis chinensis Franch. Herein, jatrorrhizine derivatives with substituted amino groups linked at the 3-position were designed, synthesized, and biologically evaluated as inhibitors of acetylcholinesterase. Jatrorrhizine derivatives inhibited the activity of acetylcholinesterase (AChE to a greater extent than the lead compound jatrorrhizine. All these jatrorrhizine derivatives were proved to be potent inhibitors of acetylcholinesterase (AChE with submicromolar IC50 values, but less sensitive to butyrylcholinesterase (BuChE, which suggests that these jatrorrhizine derivatives are selective for AChE/BuChE. Compound 3g gave the most potent inhibitor activity for AChE (IC50 = 0.301 μM, which is greater than the lead compound jatrorrhizine. All these results demonstrated that these jatrorrhizine derivatives are potential inhibitors for AChE.

Acute toxicity of organophosphorus compounds in guinea pigs is sex- and age-dependent and cannot be solely accounted for by acetylcholinesterase inhibition.

Science.gov (United States)

Fawcett, William P; Aracava, Yasco; Adler, Michael; Pereira, Edna F R; Albuquerque, Edson X

2009-02-01

This study was designed to test the hypothesis that the acute toxicity of the nerve agents S-[2-(diisopropylamino)ethyl]-O-ethyl methylphosphonothioate (VX), O-pinacolyl methylphosphonofluoridate (soman), and O-isopropyl methylphosphonofluoridate (sarin) in guinea pigs is age- and sex-dependent and cannot be fully accounted for by the irreversible inhibition of acetylcholinesterase (AChE). The subcutaneous doses of nerve agents needed to decrease 24-h survival of guinea pigs by 50% (LD(50) values) were estimated by probit analysis. In all animal groups, the rank order of LD(50) values was sarin > soman > VX. The LD(50) value of soman was not influenced by sex or age of the animals. In contrast, the LD(50) values of VX and sarin were lower in adult male than in age-matched female or younger guinea pigs. A colorimetric assay was used to determine the concentrations of nerve agents that inhibit in vitro 50% of AChE activity (IC(50) values) in guinea pig brain extracts, plasma, red blood cells, and whole blood. A positive correlation between LD(50) values and IC(50) values for AChE inhibition would support the hypothesis that AChE inhibition is a major determinant of the acute toxicity of the nerve agents. However, such a positive correlation was found only between LD(50) values and IC(50) values for AChE inhibition in brain extracts from neonatal and prepubertal guinea pigs. These results demonstrate for the first time that the lethal potencies of some nerve agents in guinea pigs are age- and sex-dependent. They also support the contention that mechanisms other than AChE inhibition contribute to the lethality of nerve agents.

Acetylcholinesterase inhibitory effects of some plants from Rosaceae

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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.

Old and new acetylcholinesterase inhibitors for Alzheimer's disease.

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Galimberti, Daniela; Scarpini, Elio

2016-10-01

To date, pharmacological treatment of Alzheimer's disease (AD) includes Acetylcholinesterase Inhibitors (AChEIs) for mild-to-moderate AD, and memantine for moderate-to-severe AD. AChEIs reversibly inhibit acetylcholinesterase (AChE), thus increasing the availability of acetylcholine in cholinergic synapses, enhancing cholinergic transmission. These drugs provide symptomatic short-term benefits, without clearly counteracting the progression of the disease. On the wake of successful clinical trials which lead to the marketing of AChEIs donepezil, rivastigmine and galantamine, many compounds with AChEI properties have been developed and tested mainly in Phase I-II clinical trials in the last twenty years. Here, we review clinical trials initiated and interrupted, and those ongoing so far. Despite many clinical trials with novel AChEIs have been carried out after the registration of those currently used to treat mild to moderate AD, none so far has been successful in a Phase III trial and marketed. Alzheimer's disease is a complex multifactorial disorder, therefore therapy should likely address not only the cholinergic system but also additional neurotransmitters. Moreover, such treatments should be started in very mild phases of the disease, and preventive strategies addressed in elderly people.

Novel bis-(−)-nor-meptazinol derivatives act as dual binding site AChE inhibitors with metal-complexing property

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Zheng, Wei [Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 200032 (China); NPFPC Key Laboratory of Contraceptives and Devices, Shanghai Institute of Planned Parenthood Research, 2140 Xietu Road, Shanghai 200032 (China); Li, Juan [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Qiu, Zhuibai [Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 200032 (China); Xia, Zheng [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Li, Wei [Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 200032 (China); Yu, Lining; Chen, Hailin; Chen, Jianxing [NPFPC Key Laboratory of Contraceptives and Devices, Shanghai Institute of Planned Parenthood Research, 2140 Xietu Road, Shanghai 200032 (China); Chen, Yan; Hu, Zhuqin; Zhou, Wei; Shao, Biyun; Cui, Yongyao [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Xie, Qiong, E-mail: xiejoanxq@gmail.com [Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 200032 (China); Chen, Hongzhuan, E-mail: yaoli@shsmu.edu.cn [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China)

2012-10-01

The strategy of dual binding site acetylcholinesterase (AChE) inhibition along with metal chelation may represent a promising direction for multi-targeted interventions in the pathophysiological processes of Alzheimer's disease (AD). In the present study, two derivatives (ZLA and ZLB) of a potent dual binding site AChE inhibitor bis-(−)-nor-meptazinol (bis-MEP) were designed and synthesized by introducing metal chelating pharmacophores into the middle chain of bis-MEP. They could inhibit human AChE activity with IC{sub 50} values of 9.63 μM (for ZLA) and 8.64 μM (for ZLB), and prevent AChE-induced amyloid-β (Aβ) aggregation with IC{sub 50} values of 49.1 μM (for ZLA) and 55.3 μM (for ZLB). In parallel, molecular docking analysis showed that they are capable of interacting with both the catalytic and peripheral anionic sites of AChE. Furthermore, they exhibited abilities to complex metal ions such as Cu(II) and Zn(II), and inhibit Aβ aggregation triggered by these metals. Collectively, these results suggest that ZLA and ZLB may act as dual binding site AChEIs with metal-chelating potency, and may be potential leads of value for further study on disease-modifying treatment of AD. -- Highlights: ► Two novel bis-(−)-nor-meptazinol derivatives are designed and synthesized. ► ZLA and ZLB may act as dual binding site AChEIs with metal-chelating potency. ► They are potential leads for disease-modifying treatment of Alzheimer's disease.

Novel bis-(−)-nor-meptazinol derivatives act as dual binding site AChE inhibitors with metal-complexing property

International Nuclear Information System (INIS)

Zheng, Wei; Li, Juan; Qiu, Zhuibai; Xia, Zheng; Li, Wei; Yu, Lining; Chen, Hailin; Chen, Jianxing; Chen, Yan; Hu, Zhuqin; Zhou, Wei; Shao, Biyun; Cui, Yongyao; Xie, Qiong; Chen, Hongzhuan

2012-01-01

The strategy of dual binding site acetylcholinesterase (AChE) inhibition along with metal chelation may represent a promising direction for multi-targeted interventions in the pathophysiological processes of Alzheimer's disease (AD). In the present study, two derivatives (ZLA and ZLB) of a potent dual binding site AChE inhibitor bis-(−)-nor-meptazinol (bis-MEP) were designed and synthesized by introducing metal chelating pharmacophores into the middle chain of bis-MEP. They could inhibit human AChE activity with IC 50 values of 9.63 μM (for ZLA) and 8.64 μM (for ZLB), and prevent AChE-induced amyloid-β (Aβ) aggregation with IC 50 values of 49.1 μM (for ZLA) and 55.3 μM (for ZLB). In parallel, molecular docking analysis showed that they are capable of interacting with both the catalytic and peripheral anionic sites of AChE. Furthermore, they exhibited abilities to complex metal ions such as Cu(II) and Zn(II), and inhibit Aβ aggregation triggered by these metals. Collectively, these results suggest that ZLA and ZLB may act as dual binding site AChEIs with metal-chelating potency, and may be potential leads of value for further study on disease-modifying treatment of AD. -- Highlights: ► Two novel bis-(−)-nor-meptazinol derivatives are designed and synthesized. ► ZLA and ZLB may act as dual binding site AChEIs with metal-chelating potency. ► They are potential leads for disease-modifying treatment of Alzheimer's disease.

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

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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. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of viologen-phosphorus dendrimers on acetylcholinesterase and butyrylcholinesterase activities.

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Ciepluch, Karol; Weber, Monika; Katir, Nadia; Caminade, Anne-Marie; El Kadib, Abdelkrim; Klajnert, Barbara; Majoral, Jean Pierre; Bryszewska, Maria

2013-03-01

The inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) is the first step in checking whether new compounds can be considered as drugs for treating neurodegenerative diseases. The effect of viologen-phosphorus dendrimers on AChE and BChE activities was studied. The results show that the effects on the cholinesterase activities depend on dendrimer type and size. Viologen dendrimers can interact with the enzymes in two ways: they can bind either to a peripheral site of the enzyme or to amino acids located near the active site, inhibiting catalysis by both cholinesterases. All tested non-toxic viologen-phosphorus dendrimers inhibited the activities of both cholinesterases, showing their potential as new drugs for treating neurodegenerative diseases. Copyright © 2012 Elsevier B.V. All rights reserved.

Design, synthesis and structure-activity relationships of dual inhibitors of acetylcholinesterase and serotonin transporter as potential agents for Alzheimer's disease.

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

2003-05-01

We have designed and synthesized a dual inhibitor of acetylcholinesterase (AChE) and serotonin transporter (SERT) as a novel class of treatment drugs for Alzheimer's disease on the basis of a hypothetical model of the AChE active site. Dual inhibitions of AChE and SERT would bring about greater therapeutic effects than AChE inhibition alone and avoid adverse peripheral effects caused by excessive AChE inhibition. Compound (S)-6j exhibited potent inhibitory activities against AChE (IC(50)=101 nM) and SERT (IC(50)=42 nM). Furthermore, (S)-6j showed inhibitory activities of both AChE and SERT in mice brain following oral administration.

Brain acetylcholinesterase activity controls systemic cytokine levels through the cholinergic anti-inflammatory pathway

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Pavlov, Valentin A.; Parrish, William R.; Rosas-Ballina, Mauricio; Ochani, Mahendar; Puerta, Margot; Ochani, Kanta; Chavan, Sangeeta; Al-Abed, Yousef; Tracey, Kevin J.

2015-01-01

The excessive release of cytokines by the immune system contributes importantly to the pathogenesis of inflammatory diseases. Recent advances in understanding the biology of cytokine toxicity led to the discovery of the “cholinergic anti-inflammatory pathway,” defined as neural signals transmitted via the vagus nerve that inhibit cytokine release through a mechanism that requires the alpha7 subunit-containing nicotinic acetylcholine receptor (α7nAChR). Vagus nerve regulation of peripheral functions is controlled by brain nuclei and neural networks, but despite considerable importance, little is known about the molecular basis for central regulation of the vagus nerve-based cholinergic anti-inflammatory pathway. Here we report that brain acetylcholinesterase activity controls systemic and organ specific TNF production during endotoxemia. Peripheral administration of the acetylcholinesterase inhibitor galantamine significantly reduced serum TNF levels through vagus nerve signaling, and protected against lethality during murine endotoxemia. Administration of a centrally-acting muscarinic receptor antagonist abolished the suppression of TNF by galantamine, indicating that suppressing acetylcholinesterase activity, coupled with central muscarinic receptors, controls peripheral cytokine responses. Administration of galantamine to α7nAChR knockout mice failed to suppress TNF levels, indicating that the α7nAChR-mediated cholinergic anti-inflammatory pathway is required for the anti-inflammatory effect of galantamine. These findings show that inhibition of brain acetylcholinesterase suppresses systemic inflammation through a central muscarinic receptor-mediated and vagal- and α7nAChR-dependent mechanism. Our data also indicate that a clinically used centrally-acting acetylcholinesterase inhibitor can be utilized to suppress abnormal inflammation to therapeutic advantage. PMID:18639629

Acotiamide Hydrochloride, a Therapeutic Agent for Functional Dyspepsia, Enhances Acetylcholine-induced Contraction via Inhibition of Acetylcholinesterase Activity in Circular Muscle Strips of Guinea Pig Stomach.

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Ito, K; Kawachi, M; Matsunaga, Y; Hori, Y; Ozaki, T; Nagahama, K; Hirayama, M; Kawabata, Y; Shiraishi, Y; Takei, M; Tanaka, T

2016-04-01

Acotiamide is a first-in-class prokinetic drug approved in Japan for the treatment of functional dyspepsia. Given that acotiamide enhances gastric motility in conscious dogs and rats, we assessed the in vitro effects of this drug on the contraction of guinea pig stomach strips and on acetylcholinesterase (AChE) activity in stomach homogenate following fundus removal. We also investigated the serotonin 5-HT4 receptor agonist mosapride, dopamine D2 receptor and AChE inhibitor itopride, and representative AChE inhibitor neostigmine. Acotiamide (0.3 and 1 μM) and itopride (1 and 3 μM) significantly enhanced the contraction of gastric body strips induced by electrical field stimulation (EFS), but mosapride (1 and 10 μM) did not. Acotiamide and itopride significantly enhanced the contraction of gastric body and antrum strips induced by acetylcholine (ACh), but not that induced by carbachol (CCh). Neostigmine also significantly enhanced the contraction of gastric body strips induced by ACh, but not that by CCh. In contrast, mosapride failed to enhance contractions induced by either ACh or CCh in gastric antrum strips. Acotiamide exerted mixed inhibition of AChE, and the percentage inhibition of acotiamide (100 μM) against AChE activity was markedly reduced after the reaction mixture was dialyzed. In contrast, itopride exerted noncompetitive inhibition on AChE activity. These results indicate that acotiamide enhances ACh-dependent contraction in gastric strips of guinea pigs via the inhibition of AChE activity, and that it exerts mixed and reversible inhibition of AChE derived from guinea pig stomach. © Georg Thieme Verlag KG Stuttgart · New York.

Molecular interaction studies of acetylcholinesterase with potential acetylcholinesterase inhibitors from the root of Rhodiola crenulata using molecular docking and isothermal titration calorimetry methods.

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Li, Fa-Jie; Liu, Yuan; Yuan, Yuan; Yang, Bin; Liu, Zhen-Ming; Huang, Lu-Qi

2017-11-01

(-)-Epicatechin gallate ((-)-ECG), 1,2,3,4,6-O-pentagalloylglucose (PGG), rhodionin, herbacetin and rhodiosin isolated from the root of Rhodiola crenulata exhibited potent, dose-dependent inhibitory effects on acetylcholinesterase (AChE) with IC 50 ranged from 57.50±5.83 to 2.43±0.34μg/mL. With the aim of explaining the differences in activity of these active ingredients and clarifying how they inhibit AChE, the AChE-inhibitor interactions were further explored using molecular docking and isothermal titration calorimetry (ITC) methods in the present study. Molecular docking studies revealed that all compounds except PGG showed binding energy values ranging from -10.30 to -8.00kcal/mol while the binding energy of galantamine, a known AChE inhibitor, was -9.53kcal/mol; they inhibited the AChE by binding into the ligand pocket with the similar binding pattern to that of galantamine by interacting with Glu199 of AChE. Inhibition constant of these active ingredients had a positive correlation with binding energy. The interaction between AChE and PGG was further evaluated with the ITC method and the results indicated that the PGG-AChE interaction was relevant to AChE concentration. The results revealed a possible mechanism for the AChE inhibition activity of these bioactive ingredients, which may provide some help in lead compounds optimization in the future. Copyright © 2017 Elsevier B.V. All rights reserved.

Acetylcholinesterase Inhibition and Antioxidant Activity of N-trans-Caffeoyldopamine and N-trans-Feruloyldopamine

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Muamer Dizdar

2018-04-01

Full Text Available Phenolic acids and their derivatives found in nature are well-known for their potential biological activity. In this study, two amides derived from trans-caffeic/ferulic acid and dopamine were synthesized and characterized by Fourier-transform infrared spectroscopy (FTIR, mass spectrometry, proton and carbon-13 nuclear magnetic resonance spectroscopy. The compounds were tested for the inhibition of acetylcholinesterase (AChE from Electrophorus electricus and for antioxidant activity by scavenging 2,2-diphenyl-1-pycrylhydrazyl free radical (DPPH• and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid radical cation (ABTS•+, reducing ferric ions, and ferrous ions chelation. N-trans-Feruloyldopamine displayed the highest inhibitory effect on AChE with half-maximal inhibitory concentration (IC50 values of 8.52 μM. In addition, an in silico study was done to determine the most favorable AChE cluster with the synthesized compounds. Further, these clusters were investigated for binding positions at the lowest free binding energy. Both synthesized hydroxycinnamates were found to be better antioxidants than the parent acids in in vitro tests applied. N-trans-Caffeoyldopamine showed the best antioxidant activity in the three tested methods—against non-biological stable free radicals IC50 5.95 μM for DPPH•, 0.24 μM for the ABTS•+ method, and for reducing power (ascorbic acid equivalent (AAE 822.45 μmol/mmol—while for chelation activity against Fe2+ ions N-trans-feruloyldopamine had slightly better antioxidant activity (IC50 3.17 mM.

Avaliação da inibição da acetilcolinesterase por extratos de plantas medicinais Evaluation of acetylcholinesterase inhibition by extracts from medicinal plants

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W.M. Mota

2012-01-01

Brazil. E. velutina aqueous extract did not have inhibitory activity, while Maytenus rigida aqueous extract showed low inhibitory activity (percentage of inhibition of 4%. Moderate inhibitory activity was detected for Phoradendron piperoides aqueous extract (percentage of inhibition of 40%, while V. agnus castus L. extract inhibited 74% AChE activity, characterized as a potent inhibitory activity. Evaluation of AChE inhibition by ethanol extracts indicated that the extracts from Sideroxylon obtusifolium, Erythrina velutina, Vitex agnus-castus L., Phoradendron piperoides, Chrysobalanus icaco, Bauhinia cheilantha and Orbignya phalerata did not show inhibitory activity. A low inhibitory activity was observed for ethanol extracts from Maytenus rigida (percentage of inhibition of 7% and Hyptis fruticosa (percentage of inhibition of 11%. Moringa oleifera ethanol extract showed moderate inhibitory activity, inhibiting 47% of the activity of this enzyme. None of the tested ethanol extracts showed potent inhibitory activity against AChE. Results of the studies of acetylcholinesterase inhibition allow the conclusion that V. agnus-castus L. aqueous extract showed to be most effective in inhibiting AChE. This result reinforces the need for continued study of this extract in order to make the partition and the purification of fractions to isolate the molecule responsible for the observed inhibition.

High Efficiency Acetylcholinesterase Immobilization on DNA Aptamer Modified Surfaces

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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.

Can hydroxylamine be a more potent nucleophile for the reactivation of tabun-inhibited AChE than prototype oxime drugs? An answer derived from quantum chemical and steered molecular dynamics studies.

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Lo, Rabindranath; Ganguly, Bishwajit

2014-07-29

Organophosphorus nerve agents are highly toxic compounds which strongly inhibit acetylcholinesterase (AChE) in the blood and in the central nervous system (CNS). Tabun is one of the highly toxic organophosphorus (OP) compounds and is resistant to many oxime drugs formulated for the reactivation of AChE. The reactivation mechanism of tabun-conjugated AChE with various drugs has been examined with density functional theory and ab initio quantum chemical calculations. The presence of a lone-pair located on the amidic group resists the nucleophilic attack at the phosphorus center of the tabun-conjugated AChE. We have shown that the newly designed drug candidate N-(pyridin-2-yl)hydroxylamine, at the MP2/6-31+G*//M05-2X/6-31G* level in the aqueous phase with the polarizable continuum solvation model (PCM), is more effective in reactivating the tabun-conjugated AChE than typical oxime drugs. The rate determining activation barrier with N-(pyridin-2-yl)hydroxylamine was found to be ∼1.7 kcal mol(-1), which is 7.2 kcal mol(-1) lower than the charged oxime trimedoxime (one of the most efficient reactivators in tabun poisonings). The greater nucleophilicity index (ω(-)) and higher CHelpG charge of pyridinylhydroxylamine compared to TMB4 support this observation. Furthermore, we have also examined the reactivation process of tabun-inhibited AChE with some other bis-quaternary oxime drug candidates such as methoxime (MMB4) and obidoxime. The docking analysis suggests that charged bis-quaternary pyridinium oximes have greater binding affinity inside the active-site gorge of AChE compared to the neutral pyridinylhydroxylamine. The peripheral ligand attached to the neutral pyridinylhydroxylamine enhanced the binding with the aromatic residues in the active-site gorge of AChE through effective π-π interactions. Steered molecular dynamics (SMD) simulations have also been performed with the charged oxime (TMB4) and the neutral hydroxylamine. From protein-drug interaction

Identification and Expression of Acetylcholinesterase in Octopus vulgaris Arm Development and Regeneration: a Conserved Role for ACHE?

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Fossati, Sara Maria; Candiani, Simona; Nödl, Marie-Therese; Maragliano, Luca; Pennuto, Maria; Domingues, Pedro; Benfenati, Fabio; Pestarino, Mario; Zullo, Letizia

2015-08-01

Acetylcholinesterase (ACHE) is a glycoprotein with a key role in terminating synaptic transmission in cholinergic neurons of both vertebrates and invertebrates. ACHE is also involved in the regulation of cell growth and morphogenesis during embryogenesis and regeneration acting through its non-cholinergic sites. The mollusk Octopus vulgaris provides a powerful model for investigating the mechanisms underlying tissue morphogenesis due to its high regenerative power. Here, we performed a comparative investigation of arm morphogenesis during adult arm regeneration and embryonic arm development which may provide insights on the conserved ACHE pathways. In this study, we cloned and characterized O. vulgaris ACHE, finding a single highly conserved ACHE hydrophobic variant, characterized by prototypical catalytic sites and a putative consensus region for a glycosylphosphatidylinositol (GPI)-anchor attachment at the COOH-terminus. We then show that its expression level is correlated to the stage of morphogenesis in both adult and embryonic arm. In particular, ACHE is localized in typical neuronal sites when adult-like arm morphology is established and in differentiating cell locations during the early stages of arm morphogenesis. This possibility is also supported by the presence in the ACHE sequence and model structure of both cholinergic and non-cholinergic sites. This study provides insights into ACHE conserved roles during processes of arm morphogenesis. In addition, our modeling study offers a solid basis for predicting the interaction of the ACHE domains with pharmacological blockers for in vivo investigations. We therefore suggest ACHE as a target for the regulation of tissue morphogenesis.

Geissoschizine methyl ether, a corynanthean-type indole alkaloid from Uncaria rhynchophylla as a potential acetylcholinesterase inhibitor.

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Yang, Zhong-Duo; Duan, Dong-Zhu; Du, Juan; Yang, Ming-Jun; Li, Shuo; Yao, Xiao-Jun

2012-01-01

Geissoschizine methyl ether (1), a newly discovered strong acetylcholinesterase (AChE) inhibitor, along with six weakly active alkaloids, vallesiachotamine (2), hisuteine (3), hirsutine (4), isorhynchophylline (5), cisocorynoxeine (6) and corynoxeine (7) have been isolated from Uncaria rhynchophylla. Geissoschizine methyl ether (1) inhibited 50% of AChE activity at concentrations of 3.7 ± 0.3 µg mL(-1) while the IC(50) value of physostigmine as a standard was 0.013 ± 0.002 µg mL(-1). The mode of AChE inhibition by 1 was reversible and non-competitive. In addition, molecular modelling was performed to explore the binding mode of inhibitor 1 at the active site of AChE.

The Role of AChE in Swimming Behavior of Daphnia magna: Correlation Analysis of Both Parameters Affected by Deltamethrin and Methomyl Exposure

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Qing Ren

2017-01-01

Full Text Available The unpredictable toxicity of insecticides may cause behavior disorder of biological organisms. In order to assess the role of acetylcholinesterase (AChE in swimming behavior of Daphnia magna, a correlation analysis of both parameters in 24 h exposure of deltamethrin (DM and methomyl (MT was investigated. The behavior responses of D. magna in DM (13.36 μg/L and 33.40 μg/L and MT (19.66 μg/L and 49.15 μg/L suggested that recovery behavior in the adjustment phase was crucial, and behavior homeostasis provided them with an optimal way to achieve a wider tolerance against environmental stress. During the experiment, positive effects on AChE activity occurred in the beginning of the exposure. Even though the de novo synthesis of AChE in D. magna might help it recover, the AChE inhibition in different treatments could be observed. Some induction effects on AChE activity at the beginning of exposure occurred, and a 50% decrease may cause toxic effects on behavior. In most treatments, the results showed that both behavior strength and AChE activity stayed in the same field within a correlation circle. These results illustrated that the environmental stress caused by both DM and MT could inhibit AChE activity and subsequently induce a stepwise behavior response, though both pesticides affect it as direct and indirect inhibitors, respectively.

Impaired terrestrial and arboreal locomotor performance in the western fence lizard (Sceloporus occidentalis) after exposure to an AChE-inhibiting pesticide

International Nuclear Information System (INIS)

DuRant, Sarah E.; Hopkins, William A.; Talent, Larry G.

2007-01-01

We examined the effects of a commonly used AChE-inhibiting pesticide on terrestrial and arboreal sprint performance, important traits for predator avoidance and prey capture, in the western fence lizard (Sceloporus occidentalis). Lizards were exposed to carbaryl (2.5, 25, and 250 μg/g) and were raced before and 4, 24, and 96 h after dosing. In the terrestrial setting, exposure to low concentrations of carbaryl had stimulatory effects on performance, but exposure to the highest concentration was inhibitory. No stimulatory effects of carbaryl were noted in the arboreal environment and performance in lizards was reduced after exposure to both the medium and highest dose of carbaryl. Our findings suggest that acute exposure to high concentrations of carbaryl can have important sublethal consequences on fitness-related traits in reptiles and that arboreal locomotor performance is a more sensitive indicator of AChE-inhibiting pesticide poisoning than terrestrial locomotor performance. - Exposure to an acetylcholinesterase-inhibiting pesticide alters locomotor performance in western fence lizards

Impaired terrestrial and arboreal locomotor performance in the western fence lizard (Sceloporus occidentalis) after exposure to an AChE-inhibiting pesticide

Energy Technology Data Exchange (ETDEWEB)

DuRant, Sarah E. [Wildlife Ecotoxicology and Physiological Ecology Program, Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University, 444 Latham Hall, Blacksburg, VA 24061 (United States); University of Georgia, Savannah River Ecology Laboratory, PO Drawer E, Aiken, SC 29802 (United States); Hopkins, William A. [Wildlife Ecotoxicology and Physiological Ecology Program, Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University, 444 Latham Hall, Blacksburg, VA 24061 (United States) and University of Georgia, Savannah River Ecology Laboratory, PO Drawer E, Aiken, SC 29802 (United States)]. E-mail: hopkinsw@vt.edu; Talent, Larry G. [Department of Zoology, Oklahoma State University, Stillwater, OK 74078 (United States)

2007-09-15

We examined the effects of a commonly used AChE-inhibiting pesticide on terrestrial and arboreal sprint performance, important traits for predator avoidance and prey capture, in the western fence lizard (Sceloporus occidentalis). Lizards were exposed to carbaryl (2.5, 25, and 250 {mu}g/g) and were raced before and 4, 24, and 96 h after dosing. In the terrestrial setting, exposure to low concentrations of carbaryl had stimulatory effects on performance, but exposure to the highest concentration was inhibitory. No stimulatory effects of carbaryl were noted in the arboreal environment and performance in lizards was reduced after exposure to both the medium and highest dose of carbaryl. Our findings suggest that acute exposure to high concentrations of carbaryl can have important sublethal consequences on fitness-related traits in reptiles and that arboreal locomotor performance is a more sensitive indicator of AChE-inhibiting pesticide poisoning than terrestrial locomotor performance. - Exposure to an acetylcholinesterase-inhibiting pesticide alters locomotor performance in western fence lizards.

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

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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.

Probing the reactivation process of sarin-inhibited acetylcholinesterase with α-nucleophiles: hydroxylamine anion is predicted to be a better antidote with DFT calculations.

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Khan, Md Abdul Shafeeuulla; Lo, Rabindranath; Bandyopadhyay, Tusar; Ganguly, Bishwajit

2011-08-01

Inactivation of acetylcholinesterase (AChE) due to inhibition by organophosphorus (OP) compounds is a major threat to human since AChE is a key enzyme in neurotransmission process. Oximes are used as potential reactivators of OP-inhibited AChE due to their α-effect nucleophilic reactivity. In search of more effective reactivating agents, model studies have shown that α-effect is not so important for dephosphylation reactions. We report the importance of α-effect of nucleophilic reactivity towards the reactivation of OP-inhibited AChE with hydroxylamine anion. We have demonstrated with DFT [B3LYP/6-311G(d,p)] calculations that the reactivation process of sarin-serine adduct 2 with hydroxylamine anion is more efficient than the other nucleophiles reported. The superiority of hydroxylamine anion to reactivate the sarin-inhibited AChE with sarin-serine adducts 3 and 4 compared to formoximate anion was observed in the presence and absence of hydrogen bonding interactions of Gly121 and Gly122. The calculated results show that the rates of reactivation process of adduct 4 with hydroxylamine anion are 261 and 223 times faster than the formoximate anion in the absence and presence of such hydrogen bonding interactions. The DFT calculated results shed light on the importance of the adjacent carbonyl group of Glu202 for the reactivation of sarin-serine adduct, in particular with formoximate anion. The reverse reactivation reaction between hydroxylamine anion and sarin-serine adduct was found to be higher in energy compared to the other nucleophiles, which suggests that this α-nucleophile can be a good antidote agent for the reactivation process. Copyright © 2011 Elsevier Inc. All rights reserved.

An acetylcholinesterase biosensor based on graphene-gold nanocomposite and calcined layered double hydroxide.

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Zhai, Chen; Guo, Yemin; Sun, Xia; Zheng, Yuhe; Wang, Xiangyou

2014-05-10

In this study, a novel acetylcholinesterase-based biosensor was fabricated. Acetylcholinesterase (AChE) was immobilized onto a glassy carbon electrode (GCE) with the aid of Cu-Mg-Al calcined layered double hydroxide (CLDH). CLDH can provide a bigger effective surface area for AChE loading, which could improve the precision and stability of AChE biosensor. However, the poor electroconductibility of CLDHs could lead to the low sensitivity of AChE biosensor. In order to effectively compensate the disadvantages of CLDHs, graphene-gold nanocomposites were used for improving the electron transfer rate. Thus, the graphene-gold nanocomposite (GN-AuNPs) was firstly modified onto the GCE, and then the prepared CLDH-AChE composite was immobilized onto the modified GCE to construct a sensitive AChE biosensor for pesticides detection. Relevant parameters were studied in detail and optimized, including the pH of the acetylthiocholine chloride (ATCl) solution, the amount of AChE immobilized on the biosensor and the inhibition time governing the analytical performance of the biosensor. The biosensor detected chlorpyrifos at concentrations ranging from 0.05 to 150μg/L. The detection limit for chlorpyrifos was 0.05μg/L. Copyright © 2014 Elsevier Inc. All rights reserved.

Cyclovoltammetric acetylcholinesterase activity assay after inhibition and subsequent reactivation by using a glassy carbon electrode modified with palladium nanorods composited with functionalized C60 fullerene

International Nuclear Information System (INIS)

Ye, Cui; Zhong, Xia; Chai, Yaqin; Yuan, Ruo; Wang, Min-Qiang

2016-01-01

A glassy carbon electrode (GCE) was modified with a nanocomposite consisting of tetraoctylammonium bromide (TOAB), C 60 fullerene, and palladium nanorods (PdNRs). The PdNRs were hydrothermally prepared and had a typical width of 20 ± 2 nm. The nanocomposite forms stable films on the GCE and exhibits a reversible redox pair for the C 60 /C 60 − system while rendering the surface to be positively charged. The modified GCE was applied to fabricate an electrochemical biosensor for detecting acetylcholinesterase (AChE) by measurement of the amount of thiocholine formed from acetylthiocholine, best at a working voltage of −0.19 V (vs. SCE). The detection scheme is based on (a) measurement of the activity of ethyl paraoxon-inhibited AChE, and (b) measurement of AChE activity after reactivation with pralidoxime (2-PAM). Compared to the conventional methods using acetylthiocholine as a substrate, the dual method presented here provides data on the AChE activity after inhibition and subsequent reactivation, thereby yielding credible data on reactivated enzyme activity. The linear analytical range for AChE activity extends from 2.5 U L −1 to 250 kU·L −1 , and the detection limit is 0.83 U L −1 . (author)

Natural sesquiterpen lactones as acetylcholinesterase inhibitors

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HOMA HAJIMEHDIPOOR

2014-06-01

Full Text Available Background and the purpose of the study: The amount of elder people who suffer from Alzheimer disease is continuously increasing every year. Cholinesterase inhibitors have shown to be effective in alleviating the symptoms of the disease, thus opening a field of research for these treatments. Herbal products, owning a reputation as effective agents in many biological studies are now drawing attention for inhibiting acetylcholinesterase, in other words, Alzheimer disease. In the present study, the ability of three sesquiterpene lactones from Inula oculus-christi and I. aucheriana to inhibit AChE has been evaluated through Ellman assay.Materials and Methods: Gaillardin and pulchellin C were obtained from I. oculus-christi and britannin from I. aucheriana by chromatographic methods. They were dissolved in methanol in concentration of 3 mg/mL and the AChEI activity of the compounds was determined by Ellman method using Acethylthiocholine iodide as the substrate and 5, 5′-dithiobis-2-nitrobenzoic acid as the reagent, in 96-well plates at 405 nm.Results: AChEI activity of the examined compounds was obtained as 67.0, 25.2 and 10.9% in concentration of 300 µg/L for gaillardin, britannin and pulchellin C, respectively.Conclusion: Among the three sesquiterpene lactones, gaillardin with 67% inhibition of AChE could be considered a good candidate for future Alzheimer studies.

Synthesis and study of thiocarbonate derivatives of choline as potential inhibitors of acetylcholinesterase.

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Boyle, N A; Talesa, V; Giovannini, E; Rosi, G; Norton, S J

1997-09-12

Fourteen alkyl and aryl thiocarbonate derivatives of choline were synthesized and studied as potential inhibitors of acetylcholinesterase (AChE). Twelve of the compounds inhibited AChEs derived from calf forebrain, human red blood cells, and octopus brain ranging from low to moderately high inhibition potency. The concentration of each inhibitory compound giving 50% inhibition of enzyme activity (IC50 values, which ranged from 1 x 10(-2) to 8 x 10(-7) M) was determined and is reported; inhibitor constants (Ki values) for the most inhibitory compounds, (1-pentylthiocarbonyl)choline chloride and (1-heptylthiocarbonyl)choline chloride, were calculated from kinetic data and are also reported. The inhibitors are competitive with substrate, and they are not hydrolyzed by the AChE activities. Certain of these new compounds may provide direction for the development of new drugs that have anticholinesterase activity and may be used for the treatment of Alzheimer's disease.

Rivastigmine: the advantages of dual inhibition of acetylcholinesterase and butyrylcholinesterase and its role in subcortical vascular dementia and Parkinson’s disease dementia

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Kandiah N

2017-04-01

Full Text Available Nagaendran Kandiah,1,2 Ming-Chyi Pai,3,4 Vorapun Senanarong,5 Irene Looi,6,7 Encarnita Ampil,8 Kyung Won Park,9 Ananda Krishna Karanam,10 Stephen Christopher11 1Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, 2Duke-NUS, Graduate Medical School, Singapore; 3Division of Behavioral Neurology, Department of Neurology, 4Alzheimer’s Disease Research Center, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan City, Taiwan; 5Division of Neurology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand; 6Clinical Research Centre, 7Department of Medicine, Hospital Seberang Jaya, Penang, Malaysia; 8Department of Neurology and Psychiatry, Faculty of Medicine and Surgery, University of Santo Tomas, Manila, Philippines; 9Department of Neurology and Cognitive Disorders and Dementia Center, Institute of Convergence Bio-Health, Dong-A University College of Medicine, Busan, Republic of Korea; 10Novartis Healthcare Private Limited, Hyderabad, India; 11Novartis (Singapore Pte. Ltd., Singapore Abstract: Several studies have demonstrated clinical benefits of sustained cholinesterase inhibition with rivastigmine in Alzheimer’s disease (AD and Parkinson’s disease dementia (PDD. Unlike donepezil and galantamine that selectively inhibit acetylcholinesterase (AChE; EC 3.1.1.7, rivastigmine is a unique cholinesterase inhibitor with both AChE and butyrylcholinesterase (BuChE; EC 3.1.1.8 inhibitory activity. Rivastigmine is also available as transdermal patch that has been approved by the US Food and Drug Administration for the treatment of mild, moderate, and severe AD as well as mild-to-moderate PDD. In this review, we explore the role of BuChE inhibition in addition to AChE inhibition with rivastigmine in the outcomes of cognition, global function, behavioral symptoms, and activities of daily living. Additionally, we review the evidence supporting the use of dual

Screen-printed electrode modified with carbon black and chitosan: a novel platform for acetylcholinesterase biosensor development.

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Talarico, Daria; Arduini, Fabiana; Amine, Aziz; Cacciotti, Ilaria; Moscone, Danila; Palleschi, Giuseppe

2016-10-01

We report a screen-printed electrode (SPE) modified with a dispersion of carbon black (CB) and chitosan by drop casting. A cyclic voltammetry technique towards ferricyanide, caffeic acid, hydroquinone, and thiocholine was performed and an improvement of the electrochemical response with respect to bare SPE as well as SPE modified only with chitosan was observed. The possibility to detect thiocholine at a low applied potential with high sensitivity was exploited and an acetylcholinesterase (AChE) biosensor was developed. A dispersion of CB, chitosan, and AChE was used to fabricate this biosensor in one step by drop casting. The enzymatic activity of the immobilized AChE was determined measuring the enzymatic product thiocholine at +300 mV. Owing to the capability of organophosphorus pesticides to inhibit AChE, this biosensor was used to detect these pollutants, and paraoxon was taken as model compound. The enzyme inhibition was linearly related to the concentration of paraoxon up to 0.5 μg L(-1), and a low detection limit equal to 0.05 μg L(-1) (calculated as 10% of inhibition) was achieved. This biosensor was challenged for paraoxon detection in drinking waters with satisfactory recovery values. The use of AChE embedded in a dispersion of CB and chitosan allowed an easy and fast production of a sensitive biosensor suitable for paraoxon detection in drinking waters at legal limit levels. Graphical Abstract Biosensors based on screen-printed electrodes modified with Acetylcholinesterase, Carbon Black, and Chitosan for organophosphorus pesticide detection.

Rapid Screening and Characterization of Acetylcholinesterase Inhibitors from Yinhuang Oral Liquid Using Ultrafiltration-liquid Chromatography-electrospray Ionization Tandem Mass Spectrometry.

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Zhang, Haomin; Guo, Yinan; Meng, Lingwen; Sun, Hui; Yang, Yinping; Gao, Ying; Sun, Jiaming

2018-01-01

At present, approximately 17-25 million people in the world suffer from Alzheimer's disease (AD). The most efficacious and acceptable therapeutic drug clinically are the acetylcholinesterase inhibitors (AChEIs). Yinhuang oral liquid is a Chinese medicine preparation which contains AChEIs according to the literatures. However, no strategy has been presented for rapid screening and identification of AChEIs from Yinhuang oral liquid. To develop a method for rapid screening and identification of AChEIs from Yinhuang oral liquid using ultrafiltration-liquid chromatography-electrospray ionization tandem mass spectrometry (UF-LC-ESI-MS/MS). In this study, UF incubation conditions such as enzyme concentration, incubation time, and incubation temperature were optimized so as to get better screening results. The AChEIs from Yinhuang oral liquid were identified by high-performance liquid chromatography-ESI-MS and the improved Ellman method was used for the AChE inhibitory activity test in vitro . The results showed that Yinhuang oral liquid can inhibit the activity of AChE. We screened and identified seven compounds with potential AChE inhibitory activity from Yinhuang oral liquid, which provided experimental basis for the treatment and prevention of AD. The current technique was used to directly screen the active ingredients with acetylcholinesterase inhibition from complex traditional Chinese medicine, which was simple, rapid, accurate, and suitable for high-throughput screening of AChEI from complex systems. A UF-LC-ESI-MS/MS method for rapid screening and identification of AChEIs from Yinhuang oral liquid was developedSeven compounds were screened and identified with potential AChE inhibitory activity from Yinhuang oral liquidIt provided experimental basis of Yinhuang oral liquid for the treating and preventing AD. Abbreviations used: (AD): Alzheimer's disease; (UF-LC-ESI-MS/MS): ultrafiltration-liquid chromatography-electrospray ionization tandem mass spectrometry; (ACh

Rapid Screening and Characterization of Acetylcholinesterase Inhibitors from Yinhuang Oral Liquid Using Ultrafiltration-liquid Chromatography-electrospray Ionization Tandem Mass Spectrometry

Science.gov (United States)

Zhang, Haomin; Guo, Yinan; Meng, Lingwen; Sun, Hui; Yang, Yinping; Gao, Ying; Sun, Jiaming

2018-01-01

Background: At present, approximately 17–25 million people in the world suffer from Alzheimer's disease (AD). The most efficacious and acceptable therapeutic drug clinically are the acetylcholinesterase inhibitors (AChEIs). Yinhuang oral liquid is a Chinese medicine preparation which contains AChEIs according to the literatures. However, no strategy has been presented for rapid screening and identification of AChEIs from Yinhuang oral liquid. Objective: To develop a method for rapid screening and identification of AChEIs from Yinhuang oral liquid using ultrafiltration–liquid chromatography–electrospray ionization tandem mass spectrometry (UF-LC-ESI-MS/MS). Materials and Methods: In this study, UF incubation conditions such as enzyme concentration, incubation time, and incubation temperature were optimized so as to get better screening results. The AChEIs from Yinhuang oral liquid were identified by high-performance liquid chromatography-ESI-MS and the improved Ellman method was used for the AChE inhibitory activity test in vitro. Results: The results showed that Yinhuang oral liquid can inhibit the activity of AChE. We screened and identified seven compounds with potential AChE inhibitory activity from Yinhuang oral liquid, which provided experimental basis for the treatment and prevention of AD. Conclusion: The current technique was used to directly screen the active ingredients with acetylcholinesterase inhibition from complex traditional Chinese medicine, which was simple, rapid, accurate, and suitable for high-throughput screening of AChEI from complex systems. SUMMARY A UF-LC-ESI-MS/MS method for rapid screening and identification of AChEIs from Yinhuang oral liquid was developedSeven compounds were screened and identified with potential AChE inhibitory activity from Yinhuang oral liquidIt provided experimental basis of Yinhuang oral liquid for the treating and preventing AD. Abbreviations used: (AD): Alzheimer's disease; (UF

Relationship between calcium entry and ACh release in K+ -stimulated rat brain synaptosomes

International Nuclear Information System (INIS)

Suszkiw, J.B.; O'Leary, M.E.; Toth, G.P.

1986-01-01

This paper examines the pattern of Ca ++ entry-dependent ACh release in relation to the kinetics of Ca ++ entry, and its inactivation in rat brain synaptosomes exposed to 50 mM K 0 + for short and prolonged durations. Intrasynaptosomal ACh was radiolabeled from tritium-choline in the presence of 20 um Paraoxon to inhibit the acetylcholinesterase activity. The release of tritium-ACh was studied in superfused synaptosomal beds formed on glass microfiber filters and by rapid filtration. The intermittent stimulation of superfused synaptosomal beds by 3-min pulses of 50 mM K + evoked decremental output of tritium-ACh which reached nearly undetectable levels after the fifth stimulus

Docking and molecular dynamics studies of peripheral site ligand–oximes as reactivators of sarin-inhibited human acetylcholinesterase

NARCIS (Netherlands)

Almeida, J.S.F.D. de; Cuya Guizado, T.R.; Guimarães, A.P.; Ramalho, T.C.; Gonçalves, A.S.; Koning, M.C. de; França, T.C.C.

2016-01-01

In the present work, we performed docking and molecular dynamics simulations studies on two groups of long-tailored oximes designed as peripheral site binders of acetylcholinesterase (AChE) and potential penetrators on the blood brain barrier. Our studies permitted to determine how the tails anchor

Acetylcholinesterase triggers the aggregation of PrP 106-126

International Nuclear Information System (INIS)

Pera, M.; Roman, S.; Ratia, M.; Camps, P.; Munoz-Torrero, D.; Colombo, L.; Manzoni, C.; Salmona, M.; Badia, A.; Clos, M.V.

2006-01-01

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

Acetyl-cholinesterase Enzyme Inhibitory Effect of Calophyllum species

African Journals Online (AJOL)

Purpose: To search for new acetylcholinesterase enzyme inhibitors from Calopyllum species. Methods: Six stem bark extracts of Calophyllum inophyllum, C. soulattri, C. teysmannii, C. lowii, C. benjaminum and C. javanicum were subjected to anti-cholinesterase analysis against acetylcholinesterase (AChE) enzyme using ...

Polypyridylruthenium(II complexes exert anti-schistosome activity and inhibit parasite acetylcholinesterases.

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Madhu K Sundaraneedi

2017-12-01

Full Text Available Schistosomiasis affects over 200 million people and there are concerns whether the current chemotherapeutic control strategy (periodic mass drug administration with praziquantel (PZQ-the only licenced anti-schistosome compound is sustainable, necessitating the development of new drugs.We investigated the anti-schistosome efficacy of polypyridylruthenium(II complexes and showed they were active against all intra-mammalian stages of S. mansoni. Two compounds, Rubb12-tri and Rubb7-tnl, which were among the most potent in their ability to kill schistosomula and adult worms and inhibit egg hatching in vitro, were assessed for their efficacy in a mouse model of schistosomiasis using 5 consecutive daily i.v. doses of 2 mg/kg (Rubb12-tri and 10 mg/kg (Rubb7-tnl. Mice treated with Rubb12-tri showed an average 42% reduction (P = 0.009, over two independent trials, in adult worm burden. Liver egg burdens were not significantly decreased in either drug-treated group but ova from both of these groups showed significant decreases in hatching ability (Rubb12-tri-68%, Rubb7-tnl-56% and were significantly morphologically altered (Rubb12-tri-62% abnormal, Rubb7-tnl-35% abnormal. We hypothesize that the drugs exerted their activity, at least partially, through inhibition of both neuronal and tegumental acetylcholinesterases (AChEs, as worms treated in vitro showed significant decreases in activity of these enzymes. Further, treated parasites exhibited a significantly decreased ability to uptake glucose, significantly depleted glycogen stores and withered tubercules (a site of glycogen storage, implying drug-mediated interference in this nutrient acquisition pathway.Our data provide compelling evidence that ruthenium complexes are effective against all intra-mammalian stages of schistosomes, including schistosomula (refractory to PZQ and eggs (agents of disease transmissibility. Further, the results of this study suggest that schistosome AChE is a target of

Acetylcholinesterase inhibition and antibacterial activity of Mondia whitei adventitious roots and ex vitro-grown somatic embryogenic-biomass

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Ponnusamy Baskaran

2016-10-01

Full Text Available Mondia whitei (Hook.f. Skeels is an important endangered medicinal and commercial plant in South Africa. In vitro propagation systems are required for biomass production and bioactivity analysis to supplement wild resources/stocks. Adventitious roots from somatic embryogenic explants using suspension culture and ex vitro-grown plants produced via somatic embryogenesis were established using different plant growth regulator treatments. The adventitious root biomass and different parts of ex vitro-grown and mother plants were used to investigate the potential for acetylcholinesterase (AChE and antibacterial activities. Adventitious roots derived from 2.5 µM indole-3-acetic acid (IAA treatments and ex vitro-grown plants derived from meta-topolin riboside (mTR and IAA treatments gave the best AChE and antibacterial activities. The in vitro-established M. whitei and ex vitro biomass have comparable ability to function as inhibitors of acetylcholinesterase and antibacterial agents, and can be used as potent bioresources in traditional medicine

Crystal structure of snake venom acetylcholinesterase in complex with inhibitory antibody fragment Fab410 bound at the peripheral site: evidence for open and closed states of a back door channel.

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Bourne, Yves; Renault, Ludovic; Marchot, Pascale

2015-01-16

The acetylcholinesterase found in the venom of Bungarus fasciatus (BfAChE) is produced as a soluble, non-amphiphilic monomer with a canonical catalytic domain but a distinct C terminus compared with the other vertebrate enzymes. Moreover, the peripheral anionic site of BfAChE, a surface site located at the active site gorge entrance, bears two substitutions altering sensitivity to cationic inhibitors. Antibody Elec410, generated against Electrophorus electricus acetylcholinesterase (EeAChE), inhibits EeAChE and BfAChE by binding to their peripheral sites. However, both complexes retain significant residual catalytic activity, suggesting incomplete gorge occlusion by bound antibody and/or high frequency back door opening. To explore a novel acetylcholinesterase species, ascertain the molecular bases of inhibition by Elec410, and document the determinants and mechanisms for back door opening, we solved a 2.7-Å resolution crystal structure of natural BfAChE in complex with antibody fragment Fab410. Crystalline BfAChE forms the canonical dimer found in all acetylcholinesterase structures. Equally represented open and closed states of a back door channel, associated with alternate positions of a tyrosine phenol ring at the active site base, coexist in each subunit. At the BfAChE molecular surface, Fab410 is seated on the long Ω-loop between two N-glycan chains and partially occludes the gorge entrance, a position that fully reflects the available mutagenesis and biochemical data. Experimentally based flexible molecular docking supports a similar Fab410 binding mode onto the EeAChE antigen. These data document the molecular and dynamic peculiarities of BfAChE with high frequency back door opening, and the mode of action of Elec410 as one of the largest peptidic inhibitors targeting the acetylcholinesterase peripheral site. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

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

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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.

Assessing the reactivation efficacy of hydroxylamine anion towards VX-inhibited AChE: a computational study.

Science.gov (United States)

Khan, Md Abdul Shafeeuulla; Ganguly, Bishwajit

2012-05-01

Oximate anions are used as potential reactivating agents for OP-inhibited AChE because of they possess enhanced nucleophilic reactivity due to the α-effect. We have demonstrated the process of reactivating the VX-AChE adduct with formoximate and hydroxylamine anions by applying the DFT approach at the B3LYP/6-311 G(d,p) level of theory. The calculated results suggest that the hydroxylamine anion is more efficient than the formoximate anion at reactivating VX-inhibited AChE. The reaction of formoximate anion and the VX-AChE adduct is a three-step process, while the reaction of hydroxylamine anion with the VX-AChE adduct seems to be a two-step process. The rate-determining step in the process is the initial attack on the VX of the VX-AChE adduct by the nucleophile. The subsequent steps are exergonic in nature. The potential energy surface (PES) for the reaction of the VX-AChE adduct with hydroxylamine anion reveals that the reactivation process is facilitated by the lower free energy of activation (by a factor of 1.7 kcal mol(-1)) than that of the formoximate anion at the B3LYP/6-311 G(d,p) level of theory. The higher free energy of activation for the reverse reactivation reaction between hydroxylamine anion and the VX-serine adduct further suggests that the hydroxylamine anion is a very good antidote agent for the reactivation process. The activation barriers calculated in solvent using the polarizable continuum model (PCM) for the reactivation of the VX-AChE adduct with hydroxylamine anion were also found to be low. The calculated results suggest that V-series compounds can be more toxic than G-series compounds, which is in accord with earlier experimental observations.

Toxicological effect of herbicides (diuron and bentazon) on snake venom and electric eel acetylcholinesterase.

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Ahmed, Mushtaq; Latif, Nadia; Khan, Rehmat Ali; Ahmad, Akhlaq

2012-08-01

The toxicological effects of the active ingredients of the herbicides diuron and bentazon on the activity of acetylcholinesterase (AChE) of krait (Bungarus sindanus) venom and electric eel (Electrophorus electricus) were studied. The diuron and entazon caused non-competitive inhibition of AChE from both species. For the venom AChE, the calculated IC50 for diuron and bentazon were found to be 3.25 and 0.14 μM, while for eel AChE, the respective IC50 values were 3.6 and 0.135 μM. In comparison, bentazon was a more potent inhibitor than diuron of AChE from both species. The insecticide lindane did not have any inhibitory effect on AChE activity in either species, even when tested at high concentrations (200-800 μM).

A conformational restriction approach to the development of dual inhibitors of acetylcholinesterase and serotonin transporter as potential agents for Alzheimer's disease.

Science.gov (United States)

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

2003-10-01

Alzheimer's disease (AD) has been treated with acetylcholinesterase (AChE) inhibitors such as donepezil. However, the clinical usefulness of AChE inhibitors is limited mainly due to their adverse peripheral effects. Depression seen in AD patients has been treated with serotonin transporter (SERT) inhibitors. We considered that combining SERT and AChE inhibition could improve the clinical usefulness of AChE inhibitors. In a previous paper, we found a potential dual inhibitor, 1, of AChE (IC50=101 nM) and SERT (IC50=42 nM), but its AChE inhibition activity was less than donepezil (IC50=10 nM). Here, we report the conformationally restricted (R)-18a considerably enhanced inhibitory activity against AChE (IC50=14 nM) and SERT (IC50=6 nM).

Arisugacins A and B, novel and selective acetylcholinesterase inhibitors from Penicillium sp. FO-4259. I. Screening, taxonomy, fermentation, isolation and biological activity.

Science.gov (United States)

Kuno, F; Otoguro, K; Shiomi, K; Iwai, Y; Omura, S

1996-08-01

An in vitro screening method for selective acetylcholinesterase (AChE) inhibitors was established. Inhibitory activity of AChE and butyrylcholinesterase (BuChE) was measured and the culture broths of microorganisms that showed selective inhibition against AChE were characterized. By using this method, a strain producing the novel and selective inhibitors of AChE, arisugacins A and B, was picked out among over seven thousand microorganisms tested. Arisugacins were obtained as white powders from the culture broth together with three known compounds, territrems B and C and cyclopenin that also showed selective inhibition against AChE. Arisugacins and territrems are members of the meroterpenoid compounds. They showed potent inhibitory activities against AChE with IC50 values in range of 1.0 approximately 25.8 nM. Furthermore, they showed greater than 2,000-fold more potent inhibition against AChE than BuChE.

Synthesis, DNA Cleavage Activity, Cytotoxicity, Acetylcholinesterase Inhibition, and Acute Murine Toxicity of Redox-Active Ruthenium(II) Polypyridyl Complexes.

Science.gov (United States)

Alatrash, Nagham; Narh, Eugenia S; Yadav, Abhishek; Kim, Mahn-Jong; Janaratne, Thamara; Gabriel, James; MacDonnell, Frederick M

2017-07-06

Four mononuclear [(L-L) 2 Ru(tatpp)] 2+ and two dinuclear [(L-L) 2 Ru(tatpp)Ru(L-L) 2 ] 4+ ruthenium(II) polypyridyl complexes (RPCs) containing the 9,11,20,22-tetraazatetrapyrido[3,2-a:2',3'-c:3'',2''-l:2''',3'''-n]pentacene (tatpp) ligand were synthesized, in which L-L is a chelating diamine ligand such as 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen), 3,4,7,8-tetramethyl-1,10-phenanthroline (Me 4 phen) or 4,7-diphenyl-1,10-phenanthroline (Ph 2 phen). These Ru-tatpp analogues all undergo reduction reactions with modest reducing agents, such as glutathione (GSH), at pH 7. These, plus several structurally related but non-redox-active RPCs, were screened for DNA cleavage activity, cytotoxicity, acetylcholinesterase (AChE) inhibition, and acute mouse toxicity, and their activities were examined with respect to redox activity and lipophilicity. All of the redox-active RPCs show single-strand DNA cleavage in the presence of GSH, whereas none of the non-redox-active RPCs do. Low-micromolar cytotoxicity (IC 50 ) against malignant H358, CCL228, and MCF7 cultured cell lines was mainly restricted to the redox-active RPCs; however, they were substantially less toxic toward nonmalignant MCF10 cells. The IC 50 values for AChE inhibition in cell-free assays and the acute toxicity of RPCs in mice revealed that whereas most RPCs show potent inhibitory action against AChE (IC 50 values <15 μm), Ru-tatpp complexes as a class are surprisingly well tolerated in animals relative to other RPCs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of endosulfan on brain acetylcholinesterase activity in juvenile bluegill sunfish

International Nuclear Information System (INIS)

Dutta, Hiran M.; Arends, Dane A.

2003-01-01

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

Assisted inhibition effect of acetylcholinesterase with n-octylphosphonic acid and application in high sensitive detection of organophosphorous pesticides by matrix-assisted laser desorption/ionization Fourier transform mass spectrometry.

Science.gov (United States)

Cai, Tingting; Zhang, Li; Wang, Haoyang; Zhang, Jing; Guo, Yinlong

2011-11-14

A simple and practical approach to improve the sensitivity of acetylcholinesterase (AChE)-inhibited method has been developed for monitoring organophosphorous (OP) pesticide residues. In this work, matrix-assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS) was used to detect AChE activity. Due to its good salt-tolerance and low sample consumption, MALDI-FTMS facilitates rapid and high-throughput screening of OP pesticides. Here we describe a new method to obtain low detection limits via employing external reagents. Among candidate compounds, n-octylphosphonic acid (n-Octyl-PA) displays assistant effect to enhance AChE inhibition by OP pesticides. In presence of n-Octyl-PA, the percentages of AChE inhibition still kept correlation with OP pesticide concentrations. The detection limits were improved significantly even by 10(2)-10(3) folds in comparison with conventional enzyme-inhibited methods. Different detection limits of OP pesticides with different toxicities were as low as 0.005 μg L(-1) for high toxic pesticides and 0.05 μg L(-1) for low toxic pesticides. Besides, the reliability of results from this method to analyze cowpea samples had been demonstrated by liquid-chromatography tandem mass spectrometry (LC-MS/MS). The application of this commercial available assistant agent shows great promise to detect OP compounds in complicated biological matrix and broadens the mind for high sensitivity detection of OP pesticide residues in agricultural products. Copyright © 2011 Elsevier B.V. All rights reserved.

Acute effects of chlorpyryphos-ethyl and secondary treated effluents on acetylcholinesterase and butyrylcholinesterase activities in Carcinus maenas

Institute of Scientific and Technical Information of China (English)

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.

Comparative effect of pesticides on brain acetylcholinesterase in tropical fish.

Science.gov (United States)

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

2012-12-15

Monitoring of pesticides based on acetylcholinesterase (AChE; EC 3.1.1.7) inhibition in vitro avoids interference of detoxification defenses and bioactivation of some of those compounds in non-target tissues. Moreover, environmental temperature, age and stress are able to affect specific enzyme activities when performing in vivo studies. Few comparative studies have investigated the inter-specific differences in AChE activity in fish. Screening studies allow choosing the suitable species as source of AChE to detect pesticides in a given situation. Brain AChE from the tropical fish: pirarucu (Arapaima gigas), cobia (Rachycentron canadum) and Nile tilapia (Oreochromis niloticus) were characterized and their activities were assayed in the presence of pesticides (the organophosphates: dichlorvos, diazinon, chlorpyrifos, temephos, tetraethyl pyrophosphate- TEPP and the carbamates: carbaryl and carbofuran). Inhibition parameters (IC₅₀ and Ki) for each species were found and compared with commercial AChE from electric eel (Electrophorus electricus). Optimal pH and temperature were found to be 8.0 and 35-45 °C, respectively. A. gigas AChE retained 81% of the activity after incubation at 50 °C for 30 min. The electric eel enzyme was more sensitive to the compounds (mainly carbofuran, IC₅₀ of 5 nM), excepting the one from A. gigas (IC₅₀ of 9 nM) under TEPP inhibition. These results show comparable sensitivity between purified and non-purified enzymes suggesting them as biomarkers for organophosphorus and carbamate detection in routine environmental and food monitoring programs for pesticides. Copyright © 2012 Elsevier B.V. All rights reserved.

Chitooligosaccharides suppress the level of protein expression and acetylcholinesterase activity induced by Abeta25-35 in PC12 cells.

Science.gov (United States)

Lee, Sang-Hoon; Park, Jin-Sook; Kim, Se-Kwon; Ahn, Chang-Bum; Je, Jae-Young

2009-02-01

Clinical applications of acetylcholinesterase (AChE) inhibitors are widespread in Alzheimer's sufferers in order to activate central cholinergic system and alleviate cognitive deficits by inhibiting the hydrolysis of acetylcholine. In this study, six kinds of chitooligosaccharides (COSs) with different molecular weight and degree of deacetylation were examined for their inhibitory effects against AChE. The 90-COSs exhibited potent AChE inhibitory activities compared to 50-COSs, while 90-MMWCOS (1000-5000 Da) in the 90-COSs showed the highest activity. Cell culture experiment revealed that 90-MMWCOS suppressed the level of AChE protein expression and AChE activity induced by Abeta(25-35) in PC12 cell lines.

Morphological alterations and acetylcholinesterase and monoamine oxidase inhibition in liver of zebrafish exposed to Aphanizomenon flos-aquae DC-1 aphantoxins

Energy Technology Data Exchange (ETDEWEB)

Zhang, De Lu, E-mail: deluzh@163.com [Department of Lifescience and Biotechnology, School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070 (China); Zhang, Jing [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Hu, Chun Xiang, E-mail: cxhu@ihb.ac.cn [Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072 (China); Wang, Gao Hong; Li, Dun Hai; Liu, Yong Ding [Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072 (China)

2014-12-15

Highlights: • Aphantoxins induced zebrafish hepatic physiological and morphological changes. • AChE and MAO inhibition reflected abnormality of neurotransmitter inactivation. • ROS advance and T-AOC reduction suggested oxidative stress. • ALT, AST, histological and ultrastructural alterations indicated hepatic damage. - Abstract: Aphanizomenon flos-aquae is a cyanobacterium that produces neurotoxins or paralytic shellfish poisons (PSPs) called aphantoxins, which present threats to environmental safety and human health via eutrophication of water bodies worldwide. Although the molecular mechanisms of this neurotoxin have been studied, many questions remain unsolved, including those relating to in vivo hepatic neurotransmitter inactivation, physiological detoxification and histological and ultrastructural alterations. Aphantoxins extracted from the natural strain of A. flos-aquae DC-1 were analyzed by high-performance liquid chromatography. The main components were gonyautoxins 1 and 5 (GTX1, GTX5) and neosaxitoxin (neoSTX), which comprised 34.04%, 21.28%, and 12.77% respectively. Zebrafish (Danio rerio) were exposed intraperitoneally to 5.3 or 7.61 μg STX equivalents (eq)/kg (low and high doses, respectively) of A. flos-aquae DC-1 aphantoxins. Morphological alterations and changes in neurotransmitter conduction functions of acetylcholinesterase (AChE) and monoamine oxidase (MAO) in zebrafish liver were detected at different time points 1–24 h post-exposure. Aphantoxin significantly enhanced hepatic alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and histological and ultrastructural damage in zebrafish liver at 3–12 h post-exposure. Toxin exposure increased the reactive oxygen species content and reduced total antioxidative capacity in zebrafish liver, suggesting oxidative stress. AChE and MAO activities were significantly inhibited, suggesting neurotransmitter inactivation/conduction function abnormalities in zebrafish

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

International Nuclear Information System (INIS)

Kilbourn, Michael R.; Sherman, Phillip S.; Snyder, Scott E.

1999-01-01

Simplified methods for in vivo studies of acetylcholinesterase (AChE) activity in rodent brain were evaluated using N-[ 11 C]methylpiperidinyl propionate ([ 11 C]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 [ 11 C]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 [ 11 C]PMP are suitable for studies where alterations of the peripheral blood metabolism of the tracer are kept to a minimum

Biosensor for pesticide triazophos based on its inhibition of acetylcholinesterase and using a glassy carbon electrode modified with coral-like gold nanostructures supported on reduced graphene oxide

International Nuclear Information System (INIS)

Ju, Ke-Jian; Feng, Jin-Xia; Zhang, Qian-Li; Xu, Tian-Qi; Wei, Jie; Feng, Jiu-Ju; Wang, Ai-Jun

2015-01-01

A nanocomposite consisting of coral-like gold nanostructures on reduced graphene oxide (RGO) was synthesized with the assistance of dimethylbiguanide (DMBG). It was then fabricated on a glassy carbon electrode, coating with cysteamine in order to enable the immobilization of acetylcholinesterase (AChE) as a model enzyme whose activity of hydrolyzing the substrate of acetylthiocholine is inhibited by the pesticide triazophos. The biosensor has response to acetylthiocholine in the 0.3 ∼ 300 μM concentration range at 0.65 V (vs. SCE). The inhibition of the enzyme by triazophos can be determined in concentrations of up to 210 ppb, with a detection limit of 0.35 ppb of triazophos (S/N = 3). The biosensor is highly reproducible and acceptably stable. (author)

Biochemical effects of glyphosate based herbicide, Excel Mera 71 on enzyme activities of acetylcholinesterase (AChE), lipid peroxidation (LPO), catalase (CAT), glutathione-S-transferase (GST) and protein content on teleostean fishes.

Science.gov (United States)

Samanta, Palas; Pal, Sandipan; Mukherjee, Aloke Kumar; Ghosh, Apurba Ratan

2014-09-01

Effects of glyphosate based herbicide, Excel Mera 71 at a dose of 17.20mg/l on enzyme activities of acetylcholinesterase (AChE), lipid peroxidation (LPO), catalase (CAT), glutathione-S-transferase (GST) and protein content were measured in different tissues of two Indian air-breathing teleosts, Anabas testudineus (Bloch) and Heteropneustes fossilis (Bloch) during an exposure period of 30 days under laboratory condition. AChE activity was significantly increased in all the investigated tissues of both fish species and maximum elevation was observed in brain of H. fossilis, while spinal cord of A. testudineus showed minimum increment. Fishes showed significant increase LPO levels in all the tissues; highest was observed in gill of A. testudineus but lowest LPO level was observed in muscle of H. fossilis. CAT was also enhanced in both the fishes, while GST activity in liver diminished substantially and minimum was observed in liver of A. testudineus. Total protein content showed decreased value in all the tissues, maximum reduction was observed in liver and minimum in brain of A. testudineus and H. fossilis respectively. The results indicated that Excel Mera 71 caused serious alterations in the enzyme activities resulting into severe deterioration of fish health; so, AChE, LPO, CAT and GST can be used as suitable indicators of herbicidal toxicity. Copyright © 2014 Elsevier Inc. All rights reserved.

Coconut (Cocos nucifera) Ethanolic Leaf Extract Reduces Amyloid-β (1-42) Aggregation and Paralysis Prevalence in Transgenic Caenorhabditis elegans Independently of Free Radical Scavenging and Acetylcholinesterase Inhibition.

Science.gov (United States)

Manalo, Rafael Vincent; Silvestre, Maries Ann; Barbosa, Aza Lea Anne; Medina, Paul Mark

2017-04-21

Virgin coconut oil (VCO) has been the subject of several studies which have aimed to alleviate Alzheimer's disease (AD) pathology, focusing on in vitro antioxidant and acetylcholinesterase (AChE) inhibitory activities. Here, we studied an underutilized and lesser-valued part of the coconut tree, specifically the leaves, using in vitro and in vivo approaches. Coconut leaf extract (CLE) was screened for antioxidant and AChE inhibitory properties in vitro and therapeutic effects in two strains of transgenic Caenorhabditis elegans expressing amyloid-β 1-42 (Aβ 1-42 ) in muscle cells. CLE demonstrated free radical scavenging activity with an EC 50 that is 79-fold less compared to ascorbic acid, and an AChE inhibitory activity that is 131-fold less compared to Rivastigmine. Surprisingly, in spite of its low antioxidant activity and AChE inhibition, CLE reduced Aβ deposits by 30.31% in CL2006 in a dose-independent manner, and reduced the percentage of paralyzed nematodes at the lowest concentration of CLE (159.38 μg/mL), compared to dH₂O/vehicle (control). Phytochemical analysis detected glycosides, anthocyanins, and hydrolyzable tannins in CLE, some of which are known to be anti-amyloidogenic. Taken together, these findings suggest that CLE metabolites alternatively decrease AB 1-42 aggregation and paralysis prevalence independently of free radical scavenging and AChE inhibition, and this warrants further investigation on the bioactive compounds of CLE.

Acetylcholinesterase concentrations in heparinized blood of Hispaniolan Amazon parrots (Amazona ventralis).

Science.gov (United States)

Tully, Thomas N; Osofsky, Anna; Jowett, Peter L H; Hosgood, Giselle

2003-12-01

Organophosphate and carbamate pesticides inhibit acetylcholinesterase (AChE) at nerve synapses. Blood samples from 22 Hispaniolan Amazon parrots (Amazona ventralis) were assayed for cholinesterase levels by two different techniques. Using the modified Michel method, the whole-blood cholinesterase activity levels ranged from 0.082 to 0.616 deltapH/hr with a mean value of 0.35 deltapH/hr. A reference range (0.08-0.62 deltapH/hr) for cholinesterase was established in birds. The modified Ellman spectrophotometric method was used to measure AChE activity by adding acetylthiocholine or pseudocholinesterase (plasma cholinesterase) activity by adding butyrylthiocholine. The reference range of the AChE activity using the modified Ellman spectrophotometric method was 0-1.12 micromol/ml/min with a mean of 0.48 micromol/ml/min, and for pseudocholinesterase the range was 0.09-0.98 micromol/ml/min with a mean of 0.53 micromol/ml/min.

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

Energy Technology Data Exchange (ETDEWEB)

Kilbourn, Michael R. E-mail: mkilbour@umich.edu; Sherman, Phillip S.; Snyder, Scott E

1999-07-01

Simplified methods for in vivo studies of acetylcholinesterase (AChE) activity in rodent brain were evaluated using N-[{sup 11}C]methylpiperidinyl propionate ([{sup 11}C]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 [{sup 11}C]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 [{sup 11}C]PMP are suitable for studies where alterations of the peripheral blood metabolism of the tracer are kept to a minimum.

Linarin Inhibits the Acetylcholinesterase Activity In-vitro and Ex-vivo

Science.gov (United States)

Feng, Xinchi; Wang, Xin; Liu, Youping; Di, Xin

2015-01-01

Linarin is a flavone glycoside in the plants Flos chrysanthemi indici, Buddleja officinalis, Cirsium setosum, Mentha arvensis and Buddleja davidii, and has been reported to possess analgesic, antipyretic, anti-inflammatory and neuroprotective activities. In this paper, linarin was investigated for its AChE inhibitory potential both in-vitro and ex-vivo. Ellman’s colorimetric method was used for the determination of AChE inhibitory activity in mouse brain. In-vitro assays revealed that linarin inhibited AChE activity with an IC50 of 3.801 ± 1.149 μM. Ex-vivo study showed that the AChE activity was significantly reduced in both the cortex and hippocampus of mice treated intraperitoneally with various doses of linarin (35, 70 and 140 mg/Kg). The inhibition effects produced by high dose of linarin were the same as that obtained after huperzine A treatment (0.5 mg/Kg). Molecular docking study revealed that both 4’-methoxyl group and 7-O-sugar moiety of linarin played important roles in ligand-receptor binding and thus they are mainly responsible for AChE inhibitory activity. In view of its potent AChE inhibitory activity, linarin may be a promising therapeutic agent for the treatment of some diseases associated with AChE, such as glaucoma, myasthenia gravis, gastric motility and Alzheimer’s disease. PMID:26330885

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

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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.

Evaluation of the Toxicity, AChE Activity and DNA Damage Caused by Imidacloprid on Earthworms, Eisenia fetida.

Science.gov (United States)

Wang, Kai; Qi, Suzhen; Mu, Xiyan; Chai, Tingting; Yang, Yang; Wang, Dandan; Li, Dongzhi; Che, Wunan; Wang, Chengju

2015-10-01

Imidacloprid is a well-known pesticide and it is timely to evaluate its toxicity to earthworms (Eisenia fetida). In the present study, the effect of imidacloprid on reproduction, growth, acetylcholinesterase (AChE) and DNA damage in earthworms was assessed using an artificial soil medium. The median lethal concentration (LC50) and the median number of hatched cocoons (EC50) of imidacloprid to earthworms was 3.05 and 0.92 mg/kg respectively, the lowest observed effect concentration of imidacloprid about hatchability, growth, AChE activity and DNA damage was 0.02, 0.5, 0.1 and 0.5 mg/kg, respectively.

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

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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

Effects of carbofuran, diuron, and nicosulfuron on acetylcholinesterase activity in goldfish (Carassius auratus).

Science.gov (United States)

Bretaud, S; Toutant, J P; Saglio, P

2000-10-01

Juvenile goldfish (Carassius auratus) were exposed to three widely used pesticides; carbofuran, diuron, and nicosulfuron. Acetylcholinesterase (AChE) activity and molecular forms of AChE were first characterized in brain and skeletal muscle of unexposed fish. Skeletal muscle had higher AChE activity than brain (306 and 215 nmol/min/mg protein, respectively). In brain, four molecular forms of AChE were found: A12, G4, G2, and G1. In the muscle, three molecular forms were found A12, A8, and G2. AChE activity was then evaluated in both tissues of fish exposed to different concentration of pesticides (5, 50, and 500 microg/L) for 6, 12, 24, and 48 h. In brain, AChE activity was significantly inhibited during all the periods of exposure in response to 50 microg/L (19-28%) and 500 microg/L (85-87%) carbofuran. Such effect was observed in the muscle only at 500 microg/L (86-92%). Carbofuran had no effect on the distribution of molecular forms. Significant inhibitions (9-12%) of brain AChE activity were also observed in response to diuron and nicosulfuron at 500 microg/L during all periods of exposure and for 50 microg/L nicosulfuron after 24 and 48 h. This study pointed out short-term effects of exposure to sublethal concentrations of the three pesticides, ranging among different chemical families, on brain and muscle AChE in goldfish. Copyright 2000 Academic Press.

Amperometric Acetylcholinesterase Biosensor Based on Multilayer Multiwall Carbon Nanotubes-chitosan Composite

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Xia SUN

2011-11-01

Full Text Available A simple method for immobilization of acetylcholinesterase (AChE onto the glassy carbon electrode (GCE modified with five layers of multiwall carbon nanotubes (MWNTs-chitosan (CHIT composite was proposed, and thus a fast, sensitive and stable amperometric sensor for quantitative determination of pesticides was developed. Five layers of MWNTs-CHIT promoted electron transfer reactions at a lower potential and catalyzed the electro-oxidation of thiocholine, thus, it improved the detection sensitivity of biosensor. Based on the inhibition of pesticides to the enzymatic activity of AChE, using carbofuran as a model compound, under optimal conditions, the inhibition of carbofuran was proportional to its concentration in two ranges, from 5×10-4 to 7.5 μg/mL and 7.5 to 20 μg/mL with a detection limit of 1×10-4 μg/mL. The constructed biosensor showed prominent characteristics and performances such as good precision, acceptable stability, fast response and low detection limit, which provided a new promising tool for pesticide analysis.

Assessing joint toxicity of four organophosphate and carbamate insecticides in common carp (Cyprinus carpio) using acetylcholinesterase activity as an endpoint.

Science.gov (United States)

Wang, Yanhua; Chen, Chen; Zhao, Xueping; Wang, Qiang; Qian, Yongzhong

2015-07-01

Mixtures of organophosphate (OP) and carbamate (CB) pesticides are commonly detected in freshwater ecosystems. These pesticides inhibit the activity of acetylcholinesterase (AChE) and have potential to interfere with behaviors that may be essential for the survival of species. Although the effects of individual anticholinesterase insecticides on aquatic species have been studied for decades, the neurotoxicity of mixtures is still poorly understood. In the present study, brain AChE inhibition in carp (Cyprinus carpio) exposed to a series of concentrations of the organophosphates (malathion and triazophos) as well as the carbamates (fenobucarb and carbosulfan) was measured. In equitoxic mixtures, the observed AChE activity inhibition of the malathion plus triazophos, and triazophos plus carbosulfan mixtures, was synergism. In equivalent concentration mixtures, the combination of malathion plus fenobucarb mixture conformed to synergism, while the observed AChE activity inhibition of the remaining pairings was less than additive. Single pesticide risk assessments are likely to underestimate the impacts of these insecticides on carps in aquatic environment where mixtures occur. Moreover, mixtures of pesticides that have been commonly reported in aquatic ecosystems may pose a more important challenge than previously anticipated. Copyright © 2014 Elsevier Inc. All rights reserved.

Peripheral Inhibitor of AChE, Neostigmine, Prevents the Inflammatory Dependent Suppression of GnRH/LH Secretion during the Follicular Phase of the Estrous Cycle

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Andrzej P. Herman

2017-01-01

Full Text Available The study was designed to test the hypothesis that the inhibition of acetylcholinesterase (AChE activity at the periphery by Neostigmine (0.5 mg/animal will be sufficient to prevent inflammatory dependent suppression of the gonadotropin-releasing hormone (GnRH/luteinising hormone (LH secretion in ewes in the follicular phase of the estrous cycle, and this effect will be comparable with the systemic AChE inhibitor, Donepezil (2.5 mg/animal. An immune/inflammatory challenge was induced by peripheral administration of lipopolysaccharide (LPS; 400 ng/kg. Peripheral treatment with Donepezil and Neostigmine prevented the LPS-induced decrease (P<0.05 in LHβ gene expression in the anterior pituitary gland (AP and in LH release. Moreover, Donepezil completely abolished (P<0.05 the suppressory effect of inflammation on GnRH synthesis in the preoptic area, when pretreatment with Neostigmine reduced (P<0.05 the decrease in GnRH content in this hypothalamic structure. Moreover, administration of both AChE inhibitors diminished (P<0.05 the inhibitory effect of LPS treatment on the expression of GnRH receptor in the AP. Our study shows that inflammatory dependent changes in the GnRH/LH secretion may be eliminated or reduced by AChE inhibitors suppressing inflammatory reaction only at the periphery such as Neostigmine, without the need for interfering in the central nervous system.

Acetylcholinesterase assay for cerebrospinal fluid using bupivacaine to inhibit butyrylcholinesterase

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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.

Kinetic analysis of interactions of paraoxon and oximes with human, Rhesus monkey, swine, rabbit, rat and guinea pig acetylcholinesterase.

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Worek, Franz; Aurbek, Nadine; Wille, Timo; Eyer, Peter; Thiermann, Horst

2011-01-15

Previous in vitro studies showed marked species differences in the reactivating efficiency of oximes between human and animal acetylcholinesterase (AChE) inhibited by organophosphorus (OP) nerve agents. These findings provoked the present in vitro study which was designed to determine the inhibition, aging, spontaneous and oxime-induced reactivation kinetics of the pesticide paraoxon, serving as a model compound for diethyl-OP, and the oximes obidoxime, pralidoxime, HI 6 and MMB-4 with human, Rhesus monkey, swine, rabbit, rat and guinea pig erythrocyte AChE. Comparable results were obtained with human and monkey AChE. Differences between human, swine, rabbit, rat and guinea pig AChE were determined for the inhibition and reactivation kinetics. A six-fold difference of the inhibitory potency of paraoxon with human and guinea pig AChE was recorded while only moderate differences of the reactivation constants between human and animal AChE were determined. Obidoxime was by far the most effective reactivator with all tested species. Only minor species differences were found for the aging and spontaneous reactivation kinetics. The results of the present study underline the necessity to determine the inhibition, aging and reactivation kinetics in vitro as a basis for the development of meaningful therapeutic animal models, for the proper assessment of in vivo animal data and for the extrapolation of animal data to humans. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Synthesis, spectroscopic, computational (DFT/B3LYP), AChE inhibition and antioxidant studies of imidazole derivative

Science.gov (United States)

Ahmad, Faheem; Alam, Mohammad Jane; Alam, Mahboob; Azaz, Shaista; Parveen, Mehtab; Park, Soonheum; Ahmad, Shabbir

2018-01-01

The present study reports the synthesis and evaluation of biological properties of 3a,8a-dihydroxy-8-oxo-1,3,3a,8a-tetrahydroindeno[1,2-d]imidazol-2(1H)-iminium chloride (3). The structure was confirmed by the FTIR, NMR, MS, CHN microanalysis and X-ray crystallographic analysis. Quantum chemical calculations have been performed at B3LYP-D3/6-311++G(d,p) level of theory to study the molecular geometry, IR, (1H and 13C) NMR, UV/Vis spectra and other molecular parameters of the asymmetric unit of crystal of imidazole compound (3). An empirical dispersion correction to hybrid functional (B3LYP-D3) has been incorporated in the present calculations due to presence of non-covalent interaction, Cl⋯H-O, in the present compound. The remarkable agreement has been observed between theoretical data and those measured experimentally. Moreover, the Hirshfeld analysis was carried out to ascertain the secondary interactions and associated 2D fingerprint plots. The synthesized imidazole derivative showed promising antioxidant property and inhibitory activity against acetylcholinesterase (AChE). Molecular docking was also performed in order to explain in silico antioxidant studies and to ascertain the probable binding mode of compound with the amino acid residues of protein.

Acetylcholinesterase and Butyrylcholinesterase Inhibitory Activities of β-Carboline and Quinoline Alkaloids Derivatives from the Plants of Genus Peganum

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Ting Zhao

2013-01-01

Full Text Available It was reported that the main chemical constituents in plants of genus Peganum were a serial of β-carboline and quinoline alkaloids. These alkaloids were quantitatively assessed for selective inhibitory activities on acetylcholinesterase (AChE and butyrylcholinesterase (BChE by in vitro Ellman method. The results indicated that harmane was the most potent selective AChE inhibitor with an IC50 of 7.11 ± 2.00 μM and AChE selectivity index (SI, IC50 of BChE/IC50 of AChE of 10.82. Vasicine was the most potent BChE inhibitor with feature of dual AChE/BChE inhibitory activity, with an IC50 versus AChE/BChE of 13.68 ± 1.25/2.60 ± 1.47 μM and AChE SI of 0.19. By analyzing and comparing the IC50 and SI of those chemicals, it was indicated that the β-carboline alkaloids displayed more potent AChE inhibition but less BChE inhibition than quinoline alkaloids. The substituent at the C7 position of the β-carboline alkaloids and C3 and C9 positions of quinoline alkaloids played a critical role in AChE or BChE inhibition. The potent inhibition suggested that those alkaloids may be used as candidates for treatment of Alzheimer’s disease. The analysis of the quantitative structure-activity relationship of those compounds investigated might provide guidance for the design and synthesis of AChE and BChE inhibitors.

Effects of sub-lethal neurite outgrowth inhibitory concentrations of chlorpyrifos oxon on cytoskeletal proteins and acetylcholinesterase in differentiating N2a cells

Energy Technology Data Exchange (ETDEWEB)

Flaskos, J., E-mail: flaskos@vet.auth.gr [Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Nikolaidis, E. [Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Harris, W. [School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS (United Kingdom); Sachana, M. [Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Hargreaves, A.J., E-mail: alan.hargreaves@ntu.ac.uk [School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS (United Kingdom)

2011-11-15

Previous work in our laboratory has shown that sub-lethal concentrations (1-10 {mu}M) of chlorpyrifos (CPF), diazinon (DZ) and diazinon oxon (DZO) inhibit the outgrowth of axon-like neurites in differentiating mouse N2a neuroblastoma cells concomitant with altered levels and/or phosphorylation state of axonal cytoskeleton and growth-associated proteins. The aim of the present work was to determine whether chlorpyrifos oxon (CPO) was capable of inhibiting N2a cell differentiation in a similar manner. Using experimental conditions similar to our previous work, sub-lethal concentrations (1-10 {mu}M) of CPO were found to inhibit N2a cell differentiation. However, unlike previous studies with DZ and DZO, there was a high level of sustained inhibition of acetylcholinesterase (AChE) in CPO treated cells. Impairment of neurite outgrowth was also associated with reduced levels of growth associated protein-43 and neurofilament heavy chain (NFH), and the distribution of NFH in cells stained by indirect immunofluorescence was disrupted. However, in contrast to previous findings for DZO, the absolute level of phosphorylated NFH was unaffected by CPO exposure. Taken together, the findings suggest that sub-lethal concentrations of CPO inhibit axon outgrowth in differentiating N2a cells and that this effect involves reduced levels of two proteins that play key roles in axon outgrowth and maintenance. Although the inhibition of neurite outgrowth is unlikely to involve AChE inhibition directly, further work will help to determine whether the persistent inhibition of AChE by CPO can account for the different effects induced by CPO and DZO on the levels of total and phosphorylated NFH. -- Highlights: Black-Right-Pointing-Pointer Sub-lethal levels of chlorpyrifos oxon inhibit neurite outgrowth in N2a cells Black-Right-Pointing-Pointer Acetylcholinesterase exhibits sustained inhibition throughout exposure Black-Right-Pointing-Pointer The levels of neurofilament heavy chain and GAP-43

Effects of sub-lethal neurite outgrowth inhibitory concentrations of chlorpyrifos oxon on cytoskeletal proteins and acetylcholinesterase in differentiating N2a cells

International Nuclear Information System (INIS)

Flaskos, J.; Nikolaidis, E.; Harris, W.; Sachana, M.; Hargreaves, A.J.

2011-01-01

Previous work in our laboratory has shown that sub-lethal concentrations (1–10 μM) of chlorpyrifos (CPF), diazinon (DZ) and diazinon oxon (DZO) inhibit the outgrowth of axon-like neurites in differentiating mouse N2a neuroblastoma cells concomitant with altered levels and/or phosphorylation state of axonal cytoskeleton and growth-associated proteins. The aim of the present work was to determine whether chlorpyrifos oxon (CPO) was capable of inhibiting N2a cell differentiation in a similar manner. Using experimental conditions similar to our previous work, sub-lethal concentrations (1–10 μM) of CPO were found to inhibit N2a cell differentiation. However, unlike previous studies with DZ and DZO, there was a high level of sustained inhibition of acetylcholinesterase (AChE) in CPO treated cells. Impairment of neurite outgrowth was also associated with reduced levels of growth associated protein-43 and neurofilament heavy chain (NFH), and the distribution of NFH in cells stained by indirect immunofluorescence was disrupted. However, in contrast to previous findings for DZO, the absolute level of phosphorylated NFH was unaffected by CPO exposure. Taken together, the findings suggest that sub-lethal concentrations of CPO inhibit axon outgrowth in differentiating N2a cells and that this effect involves reduced levels of two proteins that play key roles in axon outgrowth and maintenance. Although the inhibition of neurite outgrowth is unlikely to involve AChE inhibition directly, further work will help to determine whether the persistent inhibition of AChE by CPO can account for the different effects induced by CPO and DZO on the levels of total and phosphorylated NFH. -- Highlights: ► Sub-lethal levels of chlorpyrifos oxon inhibit neurite outgrowth in N2a cells ► Acetylcholinesterase exhibits sustained inhibition throughout exposure ► The levels of neurofilament heavy chain and GAP-43 protein are reduced ► Neurofilament heavy chain forms aggregates in cell

Introducing Dynamic Combinatorial Chemistry: Probing the Substrate Selectivity of Acetylcholinesterase

Science.gov (United States)

Angelin, Marcus; Larsson, Rikard; Vongvilai, Pornrapee; Ramstrom, Olof

2010-01-01

In this laboratory experiment, college students are introduced to dynamic combinatorial chemistry (DCC) and apply it to determine the substrate selectivity of acetylcholinesterase (AChE). Initially, the students construct a chemical library of dynamically interchanging thioesters and thiols. Then, AChE is added and allowed to select and hydrolyze…

Acetylcholinesterase inhibition and altered locomotor behavior in the carabid beetle pterostichus

DEFF Research Database (Denmark)

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

1997-01-01

-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...... 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...... the time in locomotion, average velocity, and path length and by increasing the turning rate and frequency of stops. Females responded similarly at the two highest doses, whereas their locomotor behavior was not significantly different from the control group at the lowest dimethoate dose, suggesting a sex...

Antimicrobial activity and acetylcholinesterase inhibition by extracts from chromatin modulated fungi

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Matheus Thomaz Nogueira Silva Lima

Full Text Available ABSTRACT Major health challenges as the increasing number of cases of infections by antibiotic multiresistant microorganisms and cases of Alzheimer's disease have led to searching new control drugs. The present study aims to verify a new way of obtaining bioactive extracts from filamentous fungi with potential antimicrobial and acetylcholinesterase inhibitory activities, using epigenetic modulation to promote the expression of genes commonly silenced. For such finality, five filamentous fungal species (Talaromyces funiculosus, Talaromyces islandicus, Talaromyces minioluteus, Talaromyces pinophilus, Penicillium janthinellum were grown or not with DNA methyltransferases inhibitors (procainamide or hydralazine and/or a histone deacetylase inhibitor (suberohydroxamic acid. Extracts from T. islandicus cultured or not with hydralazine inhibited Listeria monocytogenes growth in 57.66 ± 5.98% and 15.38 ± 1.99%, respectively. Increment in inhibition of acetylcholinesterase activity was observed for the extract from P. janthinellum grown with procainamide (100%, when compared to the control extract (39.62 ± 3.76%. Similarly, inhibition of acetylcholinesterase activity increased from 20.91 ± 3.90% (control to 92.20 ± 3.72% when the tested extract was obtained from T. pinophilus under a combination of suberohydroxamic acid and procainamide. Concluding, increases in antimicrobial activity and acetylcholinesterase inhibition were observed when fungal extracts in the presence of DNA methyltransferases and/or histone deacetylase modulators were tested.

Synthesis and biological evaluation of phloroglucinol derivatives possessing α-glycosidase, acetylcholinesterase, butyrylcholinesterase, carbonic anhydrase inhibitory activity.

Science.gov (United States)

Burmaoglu, Serdar; Yilmaz, Ali O; Taslimi, Parham; Algul, Oztekin; Kilic, Deryanur; Gulcin, Ilhami

2018-02-01

A series of novel phloroglucinol derivatives were designed, synthesized, characterized spectroscopically and tested for their inhibitory activity against selected metabolic enzymes, including α-glycosidase, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and human carbonic anhydrase I and II (hCA I and II). These compounds displayed nanomolar inhibition levels and showed K i values of 1.14-3.92 nM against AChE, 0.24-1.64 nM against BChE, 6.73-51.10 nM against α-glycosidase, 1.80-5.10 nM against hCA I, and 1.14-5.45 nM against hCA II. © 2018 Deutsche Pharmazeutische Gesellschaft.

Curcumin improves episodic memory in cadmium induced memory impairment through inhibition of acetylcholinesterase and adenosine deaminase activities in a rat model.

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Akinyemi, Ayodele Jacob; Okonkwo, Princess Kamsy; Faboya, Opeyemi Ayodeji; Onikanni, Sunday Amos; Fadaka, Adewale; Olayide, Israel; Akinyemi, Elizabeth Olufisayo; Oboh, Ganiyu

2017-02-01

Curcumin, the main polyphenolic component of turmeric (Curcuma longa) rhizomes has been reported to exert cognitive enhancing potential with limited scientific basis. Hence, this study sought to evaluate the effect of curcumin on cerebral cortex acetylcholinesterase (AChE) and adenosine deaminase (ADA) activities in cadmium (Cd)-induced memory impairment in rats. Animals were divided into six groups (n = 6): saline/vehicle, saline/curcumin 12.5 mg/kg, saline/curcumin 25 mg/kg, Cd/vehicle, Cd/curcumin 12.5 mg/kg, and Cd/curcumin 25 mg/kg. Rats received Cd (2.5 mg/kg) and curcumin (12.5 and 25 mg/kg, respectively) by gavage for 7 days. The results of this study revealed that cerebral cortex AChE and ADA activities were increased in Cd-poisoned rats, and curcumin co-treatment reversed these activities to the control levels. Furthermore, Cd intoxication increased the level of lipid peroxidation in cerebral cortex with a concomitant decreased in functional sulfuhydryl (-SH) group and nitric oxide (NO), a potent neurotransmitter and neuromodulatory agent. However, the co-treatment with curcumin at 12.5 and 25 mg/kg, respectively increased the non-enzymatic antioxidant status and NO in cerebral cortex with a decreased in malondialdehyde (MDA) level. Therefore, inhibition of AChE and ADA activities as well as increased antioxidant status by curcumin in Cd-induced memory dysfunction could suggest some possible mechanism of action for their cognitive enhancing properties.

DNA damage, acetylcholinesterase activity and lysosomal stability in native and transplanted mussels (Mytilus edulis) in areas close to coastal chemical dumping sites in Denmark

DEFF Research Database (Denmark)

Rank, Jette; Lehtonen, Kari K.; Strand, Jakob

2007-01-01

Biomarkers of genotoxicity (DNA damage, measured as tail moment in the Comet assay), neurotoxicity (acetylcholinesterase inhibition, AChE) and general stress (lysosomal membrane stability, LMS) were studied in native and transplanted blue mussels (Mytilus edulis) in coastal areas of western Denmark...... of chemical pollution complex, as seen especially in the variability in results on DNA damage, and also in regard to AChE activity. These investigations further stress the importance of understanding the effects of natural factors (salinity, temperature, water levels, rain and storm events) in correct...

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

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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.

Research Advances and Detection Methodologies for Microbe-Derived Acetylcholinesterase Inhibitors: A Systemic Review

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Jingqian Su

2017-01-01

Full Text Available Acetylcholinesterase inhibitors (AChEIs are an attractive research subject owing to their potential applications in the treatment of neurodegenerative diseases. Fungi and bacteria are major producers of AChEIs. Their active ingredients of fermentation products include alkaloids, terpenoids, phenylpropanoids, and steroids. A variety of in vitro acetylcholinesterase inhibitor assays have been developed and used to measure the activity of acetylcholinesterases, including modified Ellman’s method, thin layer chromatography bioautography, and the combined liquid chromatography-mass spectrometry/modified Ellman’s method. In this review, we provide an overview of the different detection methodologies, the microbe-derived AChEIs, and their producing strains.

Acetylcholinesterase inhibition and gill lesions in Rasbora caverii, an indigenous fish inhabiting rice field associated waterbodies in Sri Lanka.

Science.gov (United States)

Wijeyaratne, W M D N; Pathiratne, Asoka

2006-10-01

The present study was aimed at applying condition factor (CF), brain acetylcholinesterase (AChE) and gill histology as biomarkers for detecting possible exposure/effect induced by pesticides in fish residing rice field associated waterbodies in Sri Lanka. Biomarkers of an indigenous fish, Rasbora caverii collected from five sampling sites including canals near rice fields, a river and a reservoir (the reference site) were evaluated at four sampling stages covering pesticide application periods during rice cultivation season in 2004. Results indicated that CF of the fish did not show significant alterations regardless of the sampling sites or sampling stages. Site specific differences in AChE activities of the fish were not evident either prior to application of pesticides or at 7 days after Paraquat application to the rice fields. Two days after the application of a mixture of Fenthion and Phenthoate to the rice fields, AChE activity of the fish collected from canals near rice fields was significantly depressed (65-75%) compared to the fish in the reference site. The activities remain depressed to 50-56% even at 65 days after the insecticides application. Laboratory studies showed that prior exposure of R. caverii to Paraquat (2 microg l(-1), 7 days) enhanced the extent of inhibition of brain AChE activity induced by Fenthion (3 microg l(-1)) or a mixture of Fenthion (3 microg l(-1)) and Phenthoate (5 microg l(-1)). Gills of fish collected from canals near rice fields exhibited abnormal multiple divisions at the tips of some secondary lamellae in addition to hyperplasia, hypertrophy and club shaped deformities. Results indicate that application of pesticides in rice culture could manifest a threat to native fish populations residing rice field associated waterbodies. The response of brain AChE and histological changes in the gills of R. caverii allowed differentiating sampling sites after insecticide applications to the rice fields. Hence, R. caverii may be

The inhibitory effect of manganese on acetylcholinesterase activity enhances oxidative stress and neuroinflammation in the rat brain

International Nuclear Information System (INIS)

Santos, Dinamene; Milatovic, Dejan; Andrade, Vanda; Batoreu, M. Camila; Aschner, Michael; Marreilha dos Santos, A.P.

2012-01-01

Highlights: ► Acetylcholinesterase (AChE) is a target of Mn in the central nervous system. ► Mn inhibits AChE, representing a novel mechanistic finding for its mode of action. ► AChE inhibition may trigger or contribute to the development of oxidative stress. ► Excess Mn can trigger the release of inflammatory mediators. ► AChE activity may serve as an early biomarker of Mn neurotoxicity. -- Abstract: Background: Manganese (Mn) is a naturally occurring element and an essential nutrient for humans and animals. However, exposure to high levels of Mn may cause neurotoxic effects. The pathological mechanisms associated with Mn neurotoxicity are poorly understood, but several reports have established it is mediated, at least in part, by oxidative stress. Objectives: The present study was undertaken to test the hypothesis that a decrease in acetylcholinesterase (AChE) activity mediates Mn-induced neurotoxicity. Methods: Groups of 6 rats received 4 or 8 intraperitoneal (i.p.) injections of 25 mg MnCl 2 /kg/day, every 48 h. Twenty-four hours after the last injection, brain AChE activity and the levels of F 2 -isoprostanes (F 2 -IsoPs) and F 4 -neuroprostanes (F 4 -NPs) (biomarkers of oxidative stress), as well as prostaglandin E 2 (PGE 2 ) (biomarker of neuroinflammation) were analyzed. Results: The results showed that after either 4 or 8 Mn doses, brain AChE activity was significantly decreased (p 2 -IsoPs and PGE 2 levels, but only after 8 doses. In rats treated with 4 Mn doses, a significant increase (p 4 -NPs levels was found. To evaluate cellular responses to oxidative stress, we assessed brain nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) and Mn-superoxide dismutase (Mn-SOD, SOD2) protein expression levels. A significant increase in Mn-SOD protein expression (p < 0.05) and a trend towards increased Nrf2 protein expression was noted in rat brains after 4 Mn doses vs. the control group, but the expression of these proteins was decreased after 8 Mn

Rosmarinus officinalis L. leaf extract improves memory impairment and affects acetylcholinesterase and butyrylcholinesterase activities in rat brain.

Science.gov (United States)

Ozarowski, Marcin; Mikolajczak, Przemyslaw L; Bogacz, Anna; Gryszczynska, Agnieszka; Kujawska, Malgorzata; Jodynis-Liebert, Jadwiga; Piasecka, Anna; Napieczynska, Hanna; Szulc, Michał; Kujawski, Radoslaw; Bartkowiak-Wieczorek, Joanna; Cichocka, Joanna; Bobkiewicz-Kozlowska, Teresa; Czerny, Boguslaw; Mrozikiewicz, Przemyslaw M

2013-12-01

Rosmarinus officinalis L. leaf as part of a diet and medication can be a valuable proposal for the prevention and treatment of dementia. The aim of the study was to assess the effects of subchronic (28-fold) administration of a plant extract (RE) (200 mg/kg, p.o.) on behavioral and cognitive responses of rats linked with acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity and their mRNA expression level in the hippocampus and frontal cortex. The passive avoidance test results showed that RE improved long-term memory in scopolamine-induced rats. The extract inhibited the AChE activity and showed a stimulatory effect on BuChE in both parts of rat brain. Moreover, RE produced a lower mRNA BuChE expression in the cortex and simultaneously an increase in the hippocampus. The study suggests that RE led to improved long-term memory in rats, which can be partially explained by its inhibition of AChE activity in rat brain. © 2013. Published by Elsevier B.V. All rights reserved.

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

International Nuclear Information System (INIS)

Petzer, Anél; Harvey, Brian H.; Petzer, Jacobus P.

2014-01-01

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 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 50 (AChE) = 0.214 μM; IC 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

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

Science.gov (United States)

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

2015-07-24

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

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

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Joana R. Almeida

2015-07-01

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

Binding free energy calculations to rationalize the interactions of huprines with acetylcholinesterase.

Science.gov (United States)

Nascimento, Érica C M; Oliva, Mónica; Andrés, Juan

2018-05-01

In the present study, the binding free energy of a family of huprines with acetylcholinesterase (AChE) is calculated by means of the free energy perturbation method, based on hybrid quantum mechanics and molecular mechanics potentials. Binding free energy calculations and the analysis of the geometrical parameters highlight the importance of the stereochemistry of huprines in AChE inhibition. Binding isotope effects are calculated to unravel the interactions between ligands and the gorge of AChE. New chemical insights are provided to explain and rationalize the experimental results. A good correlation with the experimental data is found for a family of inhibitors with moderate differences in the enzyme affinity. The analysis of the geometrical parameters and interaction energy per residue reveals that Asp72, Glu199, and His440 contribute significantly to the network of interactions between active site residues, which stabilize the inhibitors in the gorge. It seems that a cooperative effect of the residues of the gorge determines the affinity of the enzyme for these inhibitors, where Asp72, Glu199, and His440 make a prominent contribution.

Binding free energy calculations to rationalize the interactions of huprines with acetylcholinesterase

Science.gov (United States)

Nascimento, Érica C. M.; Oliva, Mónica; Andrés, Juan

2018-05-01

In the present study, the binding free energy of a family of huprines with acetylcholinesterase (AChE) is calculated by means of the free energy perturbation method, based on hybrid quantum mechanics and molecular mechanics potentials. Binding free energy calculations and the analysis of the geometrical parameters highlight the importance of the stereochemistry of huprines in AChE inhibition. Binding isotope effects are calculated to unravel the interactions between ligands and the gorge of AChE. New chemical insights are provided to explain and rationalize the experimental results. A good correlation with the experimental data is found for a family of inhibitors with moderate differences in the enzyme affinity. The analysis of the geometrical parameters and interaction energy per residue reveals that Asp72, Glu199, and His440 contribute significantly to the network of interactions between active site residues, which stabilize the inhibitors in the gorge. It seems that a cooperative effect of the residues of the gorge determines the affinity of the enzyme for these inhibitors, where Asp72, Glu199, and His440 make a prominent contribution.

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

Science.gov (United States)

Tappayuthpijarn, Pimolvan; Itharat, Arunporn; Makchuchit, Sunita

2011-12-01

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

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

International Nuclear Information System (INIS)

Rao, J.V.; Kavitha, P.

2004-01-01

The acute toxicity of azodrin (monocrotophos, an organophosphorus insecticide) was determined on a soil organism, Eisenia foetida. The median lethal concentrations (LC 50 ) were derived from a 48-h paper contact test and from artificial soil tests. The LC 50 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

Interleukin 6 modulates acetylcholinesterase activity of brain neurons

International Nuclear Information System (INIS)

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

1995-01-01

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)

Preliminary Screening a Potential AChE Inhibitor in Thai Golden Shower (Leguminosae mimosoideae Extracts

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Jakkaphun Nanuam

2013-07-01

Full Text Available Pesticides are used to control pests of agriculture products in many countries including Thailand. Since they can exert harmful effects not only on target pests but also on other useful organisms, alternative agents are investigated. We studied the capacity of the Thai golden shower (Leguminosae mimosoideae extracts (root and pod to inhibit acetyl cholinestarese (AChE in the golden apple snail (Pomacea canaliculata as a pest representative. The results showed that the percentage of AChE inhibition increased with increasing in exposure times. The inhibition expressed the same trend in both male and female apple snails. AChE inhibition was higher in extracts from root than from pod. Chromatography-Mass Spectrometer (GC-MS chromatograms demonstrated anthraquinone, an AChE inhibitor, in extracts of golden shower. Our data indicate that a potential AChE inhibitor tends to accumulate more in the root part than in the pod.

Inhibition on cholinesterase and tyrosinase by alkaloids and phenolics from Aristotelia chilensis leaves.

Science.gov (United States)

Cespedes, Carlos L; Balbontin, Cristian; Avila, Jose G; Dominguez, Mariana; Alarcon, Julio; Paz, Cristian; Burgos, Viviana; Ortiz, Leandro; Peñaloza-Castro, Ignacio; Seigler, David S; Kubo, Isao

2017-11-01

It is reported in this study the effect of isolates from leaves of Aristotelia chilensis as inhibitors of acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and tyrosinase enzymes. The aim of the paper was to evaluate the activity of A. chilensis towards different enzymes. In addition to pure compounds, extracts rich in alkaloids and phenolics were tested. The most active F5 inhibited AChE (79.5% and 89.8% at 10.0 and 20.0 μg/mL) and against BChE (89.5% and 97.8% at 10.0 and 20.0 μg/mL), showing a strong mixed-type inhibition against AChE and BChE. F3 (a mixture of flavonoids and phenolics acids), showed IC 50 of 90.7 and 59.6 μg/mL of inhibitory activity against AChE and BChE, inhibiting the acetylcholinesterase competitively. Additionally, F3 showed and high potency as tyrosinase inhibitor with IC 50 at 8.4 μg/mL. Sample F4 (anthocyanidins and phenolic composition) presented a complex, mixed-type inhibition of tyrosinase with a IC 50 of 39.8 μg/mL. The findings in this investigation show that this natural resource has a strong potential for future research in the search of new phytotherapeutic treatments for cholinergic deterioration ailments avoiding the side effects of synthetic drugs. This is the first report as cholinesterases and tyrosinase inhibitors of alkaloids and phenolics from A. chilensis leaves. Copyright © 2017 Elsevier Ltd. All rights reserved.

Insect-specific irreversible inhibitors of acetylcholinesterase in pests including the bed bug, the eastern yellowjacket, German and American cockroaches, and the confused flour beetle.

Science.gov (United States)

Polsinelli, Gregory A; Singh, Sanjay K; Mishra, Rajesh K; Suranyi, Robert; Ragsdale, David W; Pang, Yuan-Ping; Brimijoin, Stephen

2010-09-06

Insecticides directed against acetylcholinesterase (AChE) are facing increased resistance among target species as well as increasing concerns for human toxicity. The result has been a resurgence of disease vectors, insects destructive to agriculture, and residential pests. We previously reported a free cysteine (Cys) residue at the entrance to the AChE active site in some insects but not higher vertebrates. We also reported Cys-targeting methanethiosulfonate molecules (AMTSn), which, under conditions that spared human AChE, caused total irreversible inhibition of aphid AChE, 95% inhibition of AChE from the malaria vector mosquito (Anopheles gambia), and >80% inhibition of activity from the yellow fever mosquito (Aedes aegypti) and northern house mosquito (Culex pipiens). We now find the same compounds inhibit AChE from cockroaches (Blattella germanica and Periplaneta americana), the flour beetle (Tribolium confusum), the multi-colored Asian ladybird beetle (Harmonia axyridis), the bed bug (Cimex lectularius), and a wasp (Vespula maculifrons), with IC(50) values of approximately 1-11muM. Our results support further study of Cys-targeting inhibitors as conceptually novel insecticides that may be free of resistance in a range of insect pests and disease vectors and, compared with current compounds, should demonstrate much lower toxicity to mammals, birds, and fish. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Acetylcholinesterase and butyrylcholinesterase inhibitory activity of Pinus species essential oils and their constituents.

Science.gov (United States)

Bonesi, Marco; Menichini, Federica; Tundis, Rosa; Loizzo, Monica R; Conforti, Filomena; Passalacqua, Nicodemo G; Statti, Giancarlo A; Menichini, Francesco

2010-10-01

This study aimed to investigate the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity of the essential oils from Pinus nigra subsp. nigra, P. nigra var. calabrica, and P. heldreichii subsp. leucodermis. This activity is relevant to the treatment of Alzheimer's disease (AD), since cholinesterase drugs are currently the only drugs available to treat AD. P. heldreichii subsp. leucodermis exhibited the most promising activity, with IC(50) values of 51.1 and 80.6 microg/mL against AChE and BChE, respectively. An interesting activity against AChE was also observed with P. nigra subsp. nigra essential oil, with an IC(50) value of 94.4 microg/mL. Essential oils were analyzed by GC and GC-MS with the purpose of investigating their relationships with the observed activities. Among the identified constituents, terpinolene, beta-phellandrene, linalyl acetate, trans-caryophyllene, and terpinen-4-ol were tested. trans-Caryophyllene and terpinen-4-ol inhibited BChE with IC(50) values of 78.6 and 107.6 microg/mL, respectively. beta-Phellandrene was selective against AChE (IC(50) value of 120.2 microg/mL).

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

Energy Technology Data Exchange (ETDEWEB)

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

1995-12-31

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

Bivalent ligands derived from Huperzine A as acetylcholinesterase inhibitors.

Science.gov (United States)

Haviv, H; Wong, D M; Silman, I; Sussman, J L

2007-01-01

The naturally occurring alkaloid Huperzine A (HupA) is an acetylcholinesterase (AChE) inhibitor that has been used for centuries as a Chinese folk medicine in the context of its source plant Huperzia Serrata. The potency and relative safety of HupA rendered it a promising drug for the ameliorative treatment of Alzheimer's disease (AD) vis-à-vis the "cholinergic hypothesis" that attributes the cognitive decrements associated with AD to acetylcholine deficiency in the brain. However, recent evidence supports a neuroprotective role for HupA, suggesting that it could act as more than a mere palliative. Biochemical and crystallographic studies of AChE revealed two potential binding sites in the active-site gorge of AChE, one of which, the "peripheral anionic site" at the mouth of the gorge, was implicated in promoting aggregation of the beta amyloid (Abeta) peptide responsible for the neurodegenerative process in AD. This feature of AChE facilitated the development of dual-site binding HupA-based bivalent ligands, in hopes of concomitantly increasing AChE inhibition potency by utilizing the "chelate effect", and protecting neurons from Abeta toxicity. Crystal structures of AChE allowed detailed modeling and docking studies that were instrumental in enhancing the understanding of underlying principles of bivalent inhibitor-enzyme dynamics. This monograph reviews two categories of HupA-based bivalent ligands, in which HupA and HupA fragments serve as building blocks, with a focus on the recently solved crystallographic structures of Torpedo californica AChE in complex with such bifunctional agents. The advantages and drawbacks of such structured-based drug design, as well as species differences, are highlighted and discussed.

Native and tabun-inhibited cholinesterase interactions with oximes

International Nuclear Information System (INIS)

Kovarik, Z.; Katalinic, M.; Sinko, G.

2009-01-01

The phosphorylation of the serine hydroxyl group in the active site of acetylcholinesterase (AChE) inactivates this essential enzyme in neurotransmission. Its related enzyme butyrylcholinesterase (BChE) also interacts with organophosphorus compounds (OP) scavenging anti-cholinesterase agents and protects synaptic AChE from inhibition. Oximes are reactivators of AChE phosphorylated by OP including insecticides and nerve agents. The effectiveness of oxime-assisted reactivation is primarily attributed to the nucleophilic displacement rate of organophosphate, but efficiency varies with the structure of the bound organophosphate, the structure of the oxime as well as rates of several other cholinesterase's reactions. Besides reactivating cholinesterases, oximes also reversibly inhibit both cholinesterases and protect them from phosphorylation by OP. We tested oximes varying in the type of ring (pyridinium and/or imidazolium), the length and type of the linker between rings, and in the position of the oxime group on the ring to find more effective oximes to reactivate tabun-inhibited human erythrocyte AChE and plasma BChE. Herein we bring an overview of in vitro interactions of native and tabun-inhibited AChE and BChE with oximes together with conformational analysis of the oximes relating molecular properties to their reactivation potency.(author)

Performance Evaluation of Monolith Based Immobilized Acetylcholinesterase Flow-Through Reactor for Copper(II Determination with Spectrophotometric Detection

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Parawee Rattanakit

2014-01-01

Full Text Available A monolith based immobilized acetylcholinesterase (AChE flow-through reactor has been developed for the determination of copper(II using flow injection spectrophotometric system. The bioreactor was prepared inside a microcapillary column by in situ polymerization of butyl methacrylate, ethylene dimethacrylate, and 2,2-dimethoxy-1,2-diphynyletane-1-one in the presence of 1-decanol, followed by vinyl azlactone functionalization and AChE immobilization. The behavior of AChE before and after being immobilized on the monolith was evaluated by kinetic parameters from Lineweaver and Burk equation. The detection was based on measuring inhibition effect on the enzymatic activity of AChE by copper(II using Ellman’s reaction with spectrophotometric detection at 410 nm. The linear range of the calibration graph was obtained over the range of 0.02–3.00 mg L−1. The detection limit, defined as 10% inhibition (I10, was found to be 0.04 mg L−1. The repeatability was 3.35 % (n=5 for 1.00 mg L−1 of copper(II. The proposed method was applied to the determination of copper(II in natural water samples with sampling rate of 4 h−1.

Repetitive obidoxime treatment induced increase of red blood cell acetylcholinesterase activity even in a late phase of a severe methamidophos poisoning: A case report.

Science.gov (United States)

Steinritz, Dirk; Eyer, Florian; Worek, Franz; Thiermann, Horst; John, Harald

2016-02-26

Accidental self-poisoning or deliberate use in suicidal intent of organophosphorus pesticides (OPP), which are widely used in agriculture, represent a health problem worldwide. Symptoms of poisoning are characterized by acute cholinergic crisis caused by inhibition of acetylcholinesterase. A 75-year-old male patient ingested 20ml of an OPP solution containing 10% methamidophos in suicidal intent. In the course of poisoning typical clinical symptoms of cholinergic crisis (miosis, bradycardia, hypotension, hypersalivation and impairment of neurologic status) were evident. Butyryl (plasma) cholinesterase (BChE) and red blood cell acetylcholinesterase (RBC-AChE) revealed decreased activities, thus specific treatment with the enzyme reactivator obidoxime was started. Inhibitory activity of the patient's plasma indicated significant amounts of persisting methamidophos in the circulation and was still found on day 4 after ingestion. Due to missing spontaneous breathing on day 6, obidoxime was administered again. Afterwards a significant increase of RBC-AChE activity was found. The patient was extubated on day 10 and a restitution ad integrum was achieved. In conclusion, obidoxime is a potent reactivator of OPP-inhibited AChE. A repetitive and prolonged administration of obidoxime should be considered in cases of severe methamidophos poisoning and should be tailored with an advanced analytical biomonitoring. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Interactions of AChE with Aβ Aggregates in Alzheimer’s Brain: Therapeutic Relevance of IDN 5706

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Francisco Javier Carvajal

2011-09-01

Full Text Available Acetylcholinesterase (AChE; EC 3.1.1.7 plays a crucial role in the rapid hydrolysis of the neurotransmitter acetylcholine, in the central and peripheral nervous system and might also participate in non-cholinergic mechanism related to neurodegenerative diseases. Alzheimer’s disease (AD is a neurodegenerative disorder characterized by a progressive deterioration of cognitive abilities, amyloid-β peptide (Aβ accumulation and synaptic alterations. We have previously shown that AChE is able to accelerate the Aβ peptide assembly into Alzheimer-type aggregates increasing its neurotoxicity. Furthermore, AChE activity is altered in brain and blood of Alzheimer’s patients. The enzyme associated to amyloid plaques changes its enzymatic and pharmacological properties, as well as, increases its resistant to low pH, inhibitors and excess of substrate. Here, we reviewed the effects of IDN 5706, a hyperforin derivative that has potential preventive effects on the development of AD. Our results show that treatment with IDN5706 for 10 weeks increases brain AChE activity in seven month-old double transgenic mice (APPswe - PS1 and decreases the content of AChE associated with different types of amyloid plaques in this Alzheimer’s model. We concluded that early treatment with IDN 5706 decreases AChE-Aβ interaction and this effect might be of therapeutic interest in the treatment of AD.

Research of small quaternary AChE inhibitors as pretreatment of OP poisoning

International Nuclear Information System (INIS)

Musilek, K.; Komloova, M.; Holas, O.; Opletalova, V.; Pohanka, M.; Kuca, K.

2009-01-01

Small quaternary AChE inhibitors are used (e.g. pyridostigmine) or scoped (e.g. SAD-128) for pretreatment against organophosphate intoxication [1]. The pretreatment is based on competitive inhibition of AChE prior to organophosphate (OP) poisoning. Consequently, the OP can not influence the inhibited AChE and is degraded by other esterases. Although various competitive inhibitors are used globally, pyridostigmine still remains the most broaden. Its side effects including gastrointestinal effects (nausea, intestinal obstruction), increased bronchial secretion, cardiac arrhythmia or cholinergic crisis are well described. Moreover, some bisquaternary competitive inhibitors (e.g. SAD-128) were used to decrease lethal effects of OP poisoning in vivo. The further studies dealing with SAD-128 showed its increased ability to interact with brain muscarinic acetylcholine receptors as allosteric inhibitors [2]. The small molecules derived from quaternized pyridine, quinoline and isoquinoline were designed as AChE inhibitors. Their ability to inhibit AChE or BChE was determined in vitro using IC50. The IC50 data were compared within each group of compounds with emphasis on selectivity AChE versus BChE. The overall study will be presented. The work was supported by Ministry of Defence of Czech Republic No. OVUOFVZ200805.(author)

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

International Nuclear Information System (INIS)

Kalantari, H.; Siahapoosh, A.; Farsani, K. M.

2009-01-01

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

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

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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.

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

Science.gov (United States)

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. Copyright © 2016 Elsevier B.V. All rights reserved.

X-ray crystallographic studies on acetylcholinesterase and on its interaction with anticholinesterase agents. Final report, 30 April 1993-30 September 1995, FLD33 ERR CHK FLD04

Energy Technology Data Exchange (ETDEWEB)

Silman, I.; Sussman, J.

1995-12-01

The objective of this project was to solve, for the first time, by X-ray crystallography, the three-dimensional structure of acetylcholinesterase (AChE) and to learn from this structure the reaction mechanism, inhibition modes and other structural and functional properties of the enzyme. The principal objectives of the current project included: (1) Attempts to obtain crystals of cholinesterases other than T. californica AChE, in particular of AChE of human origin. (2) Collection of improved data sets, viz. at higher resolution than previously, for crystals of Torpedo AChE. (3) Determination of complexes of Torpedo AChE with various ligands, including orgamophosphates. In the this project, we have made progress towards all three objectives, as well as in additional areas related to the long-term aims of our research program.

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

International Nuclear Information System (INIS)

Mazzia, Christophe; Capowiez, Yvan; Sanchez-Hernandez, Juan C.; Koehler, Heinz-R.; Triebskorn, Rita; Rault, Magali

2011-01-01

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.

Effect of carbaryl (carbamate insecticide) on acetylcholinesterase activity of two strains of Daphnia magna (Crustacea, Cladocera).

Science.gov (United States)

Toumi, Hela; Bejaoui, Mustapha; Touaylia, Samir; Burga Perez, Karen F; Ferard, Jean François

2016-11-01

The present study was designed to investigate the effect of carbaryl (carbamate insecticide) on the acetylcholinesterase activity in two strains (same clone A) of the crustacean cladoceran Daphnia magna. Four carbaryl concentrations (0.4, 0.9, 1.8 and 3.7 µg L(-1)) were compared against control AChE activity. Our results showed that after 48 h of carbaryl exposure, all treatments induced a significant decrease of AChE activities whatever the two considered strains. However, different responses were registered in terms of lowest observed effect concentrations (LOEC: 0.4 µg L(-1) for strain 1 and 0.9 µg L(-1) for strains 2) revealing differences in sensitivity among the two tested strains of D. magna. These results suggest that after carbaryl exposure, the AChE activity responses can be also used as a biomarker of susceptibility. Moreover, our results show that strain1 is less sensitive than strain 2 in terms of IC50-48 h of AChE activity. Comparing the EC50-48 h of standard ecotoxicity test and IC50-48 h of AChE inhibition, there is the same order of sensitivity with both strains.

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

Science.gov (United States)

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.

A small-volume bioassay for quantification of the esterase inhibiting potency of mixtures of organophosphate and carbamate insecticides in rainwater : development and optimization

NARCIS (Netherlands)

Hamers, T.; Molin, K.R.J.; Koeman, J.H.; Murk, A.J.

2000-01-01

The goal of this study was to develop a sensitive in vitro bioassay for quantification of the total esterase inhibiting potency of low concentrations of organophosphate and carbamate insecticides in relatively small rainwater samples. Purified acetylcholinesterase (AChE) from electric eel

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

Science.gov (United States)

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

2002-10-03

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

Protection from the toxicity of diisopropylfluorophosphate by adeno-associated virus expressing acetylcholinesterase

International Nuclear Information System (INIS)

Li Bin; Duysen, Ellen G.; Poluektova, Larisa Y.; Murrin, L. Charles; Lockridge, Oksana

2006-01-01

Organophosphorus esters (OP) are highly toxic chemicals used as pesticides and nerve agents. Their acute toxicity is attributed to inhibition of acetylcholinesterase (AChE, EC 3.1.1.7) in nerve synapses. Our goal was to find a new therapeutic for protection against OP toxicity. We used a gene therapy vector, adeno-associated virus serotype 2 (AAV-2), to deliver murine AChE to AChE-/- mice that have no endogenous AChE activity. The vector encoded the most abundant form of AChE: exons 2, 3, 4, and 6. Two-day old animals, with an immature immune system, were injected. AChE delivered intravenously was expressed up to 5 months in plasma, liver, heart, and lung, at 5-15% of the level in untreated wild-type mice. A few mice formed antibodies, but antibodies did not block AChE activity. The plasma AChE was a mixture of dimers and tetramers. AChE delivered intramuscularly had 40-fold higher activity levels than in wild-type muscle. None of the AChE was collagen-tailed. No retrograde transport through the motor neurons to the central nervous system was detected. AChE delivered intrastriatally assembled into tetramers. In brain, the AAV-2 vector transduced neurons, but not astrocytes and microglia. Vector-treated AChE-/- mice lived longer than saline-treated controls. AChE-/- mice were protected from diisopropylfluorophosphate-induced respiratory failure when the vector was delivered intravenously, but not intrastriatally. Since vector-treated animals had no AChE activity in diaphragm muscle, protection from respiratory failure came from AChE in other tissues. We conclude that AChE scavenged OP and in this way protected the activity of butyrylcholinesterase (BChE, EC 3.1.1.8) in motor endplates

The activity of detoxifying enzymes in the infective juveniles of Heterorhabditis bacteriophora strains: Purification and characterization of two acetylcholinesterases.

Science.gov (United States)

Mohamed, Magda A; Mahdy, El-Sayed M E; Ghazy, Abd-El-Hady M; Ibrahim, Nihal M; El-Mezayen, Hatem A; Ghanem, Manal M E

2016-02-01

The infectivity and detoxifying enzyme activities including glutathione-S-transferase (GST), acetylcholinesterase (AChE) and carboxylesterase (CaE) are investigated in the infective juveniles (IJs) of six different strains of Heterorhabditis bacteriophora as a biocontrol agent against insect pests. The specific activities ranged from 10.8-29.8 and 50-220units/mg protein for GST and AChE, respectively; and from 24.7-129 and 22.6-77.3units/mg protein for CaE as estimated by P-nitrophenyl and α-naphthyl acetates, respectively. H. bacteriophora EM2 strain has the highest infectivity and the highest enzymatic activities as well. AChE is the predominant detoxifying enzyme that might imply its major role in the detoxification of insecticide(s). The isoenzyme pattern demonstrated two major slow-moving isoforms in all EPN strains examined. Purification of two AChE isoforms, AChEAII and AChEBI, from H. bacteriophora EM2 strain is performed by ammonium sulfate precipitation, gel filtration on Sephacryl S-200 and chromatography on DEAE-Sepharose. AChEAII and AChEBII have specific activities of 1207 and 1560unit/mg protein, native molecular weights of 180 and 68kDa, and are found in dimeric and monomeric forms, respectively. Both isoforms showed optimum activity at pH8.5 and 35°C. AChEBI exhibited higher thermal stability and higher activation energy than AChEAII. The enzymatic activities of purified AChEs are completely inhibited by Hg(+2) and Ni(+2) and greatly enhanced by Mn(+2). The substrate specificity, the relative efficiency of substrates hydrolysis, substrate inhibition and inhibition by BW284C51, but not by iso-OMPA, clearly indicated that they are true AChEs; their properties are compared with those recorded for insects as target hosts for H. bacteriophora EM2. Copyright © 2015 Elsevier Inc. All rights reserved.

Surface display and bioactivity of Bombyx mori acetylcholinesterase on Pichia pastoris

Science.gov (United States)

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...

Acetylcholinesterase and Nissl staining in the same histological section.

Science.gov (United States)

Shipley, M T; Ennis, M; Behbehani, M M

1989-12-18

Acetylcholinesterase (AChE) enzyme histochemistry and Nissl staining are commonly utilized in neural architectonic studies. However, the opaque reaction deposit produced by the most commonly used AChE histochemical methods is not compatible with satisfactory Nissl staining. As a result, precise correlation of AChE and Nissl staining necessitates time-consuming comparisons of adjacent sections which may have differential shrinkage. Here, we have modified the Koelle-Friedenwald histochemical reaction for AChE by omitting the final intensification steps. The modified reaction yields a non-opaque reaction product that is selectively visualized by darkfield illumination. This non-intensified darkfield AChE (NIDA) reaction allows clear visualization of Nissl staining in the same histological section. This combined AChE-Nissl method greatly facilitates detailed correlation of enzyme and cytoarchitectonic organization.

Acetylcholinesterase activity of electric eel is increased or decreased by selected monoterpenoids and phenylpropanoids in a concentration-dependent manner.

Science.gov (United States)

López, María Dolores; Campoy, Francisco J; Pascual-Villalobos, María Jesús; Muñoz-Delgado, Encarnación; Vidal, Cecilio J

2015-03-05

The profitable insecticidal action of monoterpenoids prompted us to test their efficiency against stored-grain beetle species, via inhibition of acetylcholinesterase (AChE). For this, we first studied the ability of the monoterpenoids geraniol, linalool, camphor, fenchone, carvone and γ-terpinene, besides the phenylpropanoids trans-anethole and estragole to inhibit Electrophorus AChE. The results indicated that while AChE activity increased (15-35%) with 40 μM geraniol, camphor, γ-terpinene and linalool, the activity decreased (60-40%) with 5mM carvone, γ-terpinene, and fenchone. The Km for AChE was 0.52 ± 0.02 mM in control assays, which fell to 0.28 ± 0.01 mM or 0.32 ± 0.01 mM in assays with 20 μM linalool or γ-terpinene added. In the millimolar range, the terpenoids behaved as weak inhibitors. Unexpectedly, AChE inhibition by camphor, carvone, γ-terpinene, and fenchone gave Hill numbers ranging 2.04-1.57, supporting the idea that AChE was able to lodge more than one monoterpenoid molecule. The plots of 1/v vs. 1/S at varying monoterpenoid provided straight lines, fenchone and γ-terpinene acting as competitive inhibitors and carvone and camphor as non-competitive inhibitors. Moreover, the secondary plots of the slope KM(app)/Vmax(app) vs. [I] and of 1/Vmax(app) vs. [I] gave parabolic curves, which lent support to the proposed capacity of AChE to bind more than one monoterpenoid molecule. The fitting of the curves to a second-order polynomial equation allowed us to calculate the inhibition constants for the interaction of AChE with fenchone, γ-terpinene, carvone and camphor. The previously unnoticed increase in AChE activity with monoterpenoids should be considered as a reminder when advising the use of essential oils of plants or their constituents as anti-AChE agents to attenuate pathological signs of Alzheimer's disease. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A fluorescence assay for measuring acetylcholinesterase activity in rat blood and a human neuroblastoma cell line (SH-SY5Y).

Science.gov (United States)

Santillo, Michael F; Liu, Yitong

2015-01-01

Acetylcholinesterase (AChE) is an enzyme responsible for metabolism of the neurotransmitter acetylcholine, and inhibition of AChE can have therapeutic applications (e.g., drugs for Alzheimer's disease) or neurotoxic consequences (e.g., pesticides). A common absorbance-based AChE activity assay that uses 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) can have limited sensitivity and be prone to interference. Therefore, an alternative assay was developed, in which AChE activity was determined by measuring fluorescence of resorufin produced from coupled enzyme reactions involving acetylcholine and Amplex Red (10-acetyl-3,7-dihydroxyphenoxazine). The Amplex Red assay was used for two separate applications. First, AChE activity was measured in rat whole blood, which is a biomarker for exposure to AChE inhibitor pesticides. Activity was quantified from a 10(5)-fold dilution of whole blood, and there was a linear correlation between Amplex Red and DTNB assays. For the second application, Amplex Red assay was used to measure AChE inhibition potency in a human neuroblastoma cell line (SH-SY5Y), which is important for assessing pharmacological and toxicological potential of AChE inhibitors including drugs, phytochemicals, and pesticides. Five known reversible inhibitors were evaluated (IC50, 7-225 nM), along with irreversible inhibitors chlorpyrifos-oxon (ki=1.01 nM(-1)h(-1)) and paraoxon (ki=0.16 nM(-1)h(-1)). Lastly, in addition to inhibition, AChE reactivation was measured in SH-SY5Y cells incubated with pralidoxime chloride (2-PAM). The Amplex Red assay is a sensitive, specific, and reliable fluorescence method for measuring AChE activity in both rat whole blood and cultured SH-SY5Y cells. Published by Elsevier Inc.

beta-Aminoalcohols as Potential Reactivators of Aged Sarin-/Soman-Inhibited Acetylcholinesterase

Science.gov (United States)

2017-02-08

The calculations suggest that the designed b-aminoalcohol can selectively reactivate aged sarin-/soman-inhibited AChE. Fur - thermore, unlike existing...Kolossv#ry, K. F. Wong, F. Paesani, J. Vanicek, X. Wu, S. R. Brozell, T. Steinbrecher, H. Gohlke, L. Yang, C. Tan , J. Mongan, V. Hornak, G. Cui, D. H

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

OpenAIRE

ŞENDEMİR, Erdoğan

2014-01-01

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...

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

DEFF Research Database (Denmark)

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

2001-01-01

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

Benefits of statistical molecular design, covariance analysis, and reference models in QSAR: a case study on acetylcholinesterase

Science.gov (United States)

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.

Acetylcholinesterase of Rhipicephalus (Boophilus) microplus and Phlebotomus papatasi: Gene identification, expression, and biochemical properties of recombinant proteins

Science.gov (United States)

Rhipicephalus (Boophilus) microplus (Bm) ticks are vectors of bovine babesiosis and anaplasmosis. Tick resistance to organophosphate (OP) acaricide involves acetylcholinesterase (AChE) insensitivity to OP and metabolic detoxification. Sequencing and in vitro expression of Bm genes encoding AChE allo...

Acetylcholinesterases of Rhipicephalus (Boophilus) microplus and Phlebotomus papatasi: Gene identification, expression and biochemical properties of recombinant proteins

Science.gov (United States)

Rhipicephalus (Boophilus) microplus (Bm) is a vector of bovine babesiosis and anaplasmosis. Tick resistance to organophosphate (OP) acaricide involves acetylcholinesterase (AChE) insensitivity to OP and metabolic detoxification. In vitro expression of Bm genes encoding AChE allowed biochemical chara...

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

International Nuclear Information System (INIS)

Shenouda, Josephine; Green, Paula; Sultatos, Lester

2009-01-01

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 K m 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 k i of 3048 nM -1 h -1 , and a K D 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 k i increasing as the inhibitor concentration decreased. Chlorpyrifos oxon concentrations of 10 and 0.3 nM gave k i s 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.

Integrated Use of Biomarkers (O : N Ratio and Acetylcholinesterase Inhibition) on Aulacomya ater (Molina, 1782) (Bivalvia: Mytilidae) as a Criteria for Effects of Organophosphate Pesticide Exposition

Science.gov (United States)

Führer, Eduardo; Rudolph, Anny; Espinoza, Claudio; Díaz, Rodrigo; Gajardo, Marisol; Camaño, Nuria

2012-01-01

The effect of residual concentrations of organophosphate pesticide chlorpyrifos (Lorsban 4E) on the activity of the acetylcholinesterase enzyme and oxygen : nitrogen ratio in the mussel Aulacomya ater was analyzed. Toxicity tests show a sensitivity to the pesticide in the bivalve estimated at 16 μg L−1 (LC50−96 hours). Concentrations between 0.2 and 1.61 μg L−1 were able to inhibit significantly the AChE activity, and concentrations between 0.8 and 1.61 μg L−1 stimulate ammonia excretion and decrease oxygen : ammonia-N (O : N) ratio, with respect to the control group. A. ater proved to be a species sensitive to pesticide exposure and easy to handle in lab conditions. Thus, it is recommended as a bioindicator for use in programs of environmental alertness in the Eastern South Pacific coastal zone. PMID:22619673

Metformin and Its Sulfenamide Prodrugs Inhibit Human Cholinesterase Activity

Directory of Open Access Journals (Sweden)

Magdalena Markowicz-Piasecka

2017-01-01

Full Text Available The results of epidemiological and pathophysiological studies suggest that type 2 diabetes mellitus (T2DM may predispose to Alzheimer’s disease (AD. The two conditions present similar glucose levels, insulin resistance, and biochemical etiologies such as inflammation and oxidative stress. The diabetic state also contributes to increased acetylcholinesterase (AChE activity, which is one of the factors leading to neurodegeneration in AD. The aim of this study was to assess in vitro the effects of metformin, phenformin, and metformin sulfenamide prodrugs on the activity of human AChE and butyrylcholinesterase (BuChE and establish the type of inhibition. Metformin inhibited 50% of the AChE activity at micromolar concentrations (2.35 μmol/mL, mixed type of inhibition and seemed to be selective towards AChE since it presented low anti-BuChE activity. The tested metformin prodrugs inhibited cholinesterases (ChE at nanomolar range and thus were more active than metformin or phenformin. The cyclohexyl sulfenamide prodrug demonstrated the highest activity towards both AChE (IC50 = 890 nmol/mL, noncompetitive inhibition and BuChE (IC50 = 28 nmol/mL, mixed type inhibition, while the octyl sulfenamide prodrug did not present anti-AChE activity, but exhibited mixed inhibition towards BuChE (IC50 = 184 nmol/mL. Therefore, these two bulkier prodrugs were concluded to be the most selective compounds for BuChE over AChE. In conclusion, it was demonstrated that biguanides present a novel class of inhibitors for AChE and BuChE and encourages further studies of these compounds for developing both selective and nonselective inhibitors of ChEs in the future.

Upregulation of α7 Nicotinic Receptors by Acetylcholinesterase C-Terminal Peptides

Science.gov (United States)

Bond, Cherie E.; Zimmermann, Martina; Greenfield, Susan A.

2009-01-01

Background The alpha-7 nicotinic acetylcholine receptor (α7-nAChR) is well known as a potent calcium ionophore that, in the brain, has been implicated in excitotoxicity and hence in the underlying mechanisms of neurodegenerative disorders such as Alzheimer's disease. Previous research implied that the activity of this receptor may be modified by exposure to a peptide fragment derived from the C-terminal region of the enzyme acetylcholinesterase. This investigation was undertaken to determine if the functional changes observed could be attributed to peptide binding interaction with the α7-nAChR, or peptide modulation of receptor expression. Methodology/Principal Findings This study provides evidence that two peptides derived from the C-terminus of acetylcholinesterase, not only selectively displace specific bungarotoxin binding at the α7-nAChR, but also alter receptor binding properties for its familiar ligands, including the alternative endogenous agonist choline. Of more long-term significance, these peptides also induce upregulation of α7-nAChR mRNA and protein expression, as well as enhancing receptor trafficking to the plasma membrane. Conclusions/Significance The results reported here demonstrate a hitherto unknown relationship between the α7-nAChR and the non-enzymatic functions of acetylcholinesterase, mediated independently by its C-terminal domain. Such an interaction may prove valuable as a pharmacological tool, prompting new approaches for understanding, and combating, the process of neurodegeneration. PMID:19287501

High-performance liquid chromatography-mass spectrometry-based acetylcholinesterase assay for the screening of inhibitors in natural extracts

NARCIS (Netherlands)

de Jong, C.F.; Derks, R.J.E.; Bruyneel, B.; Niessen, W.M.A.; Irth, H.

2006-01-01

The present paper describes a High-performance liquid chromatography-mass spectrometry (LC-MS) methodology for the screening of acetylcholinesterase (AChE) inhibitors in natural extracts. AChE activity of sample components is monitored by a post-column biochemical assay that is based on the

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

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Ilkay Erdogan Orhan

2011-01-01

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

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

Directory of Open Access Journals (Sweden)

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.

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

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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.

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

NARCIS (Netherlands)

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

2008-01-01

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

Is acetylcholinesterase a biomarker of susceptibility in Daphnia magna (Crustacea, Cladocera) after deltamethrin exposure?

Science.gov (United States)

Toumi, Héla; Boumaiza, Moncef; Millet, Maurice; Radetski, Claudemir Marcos; Felten, Vincent; Férard, Jean François

2015-02-01

In the present study, we explored the possibility of using the acetylcholinesterase (AChE) as a biomarker after deltamethrin (pyrethroid insecticide) exposure with three strains of the cladoceran Daphnia magna. Four calculated time-weighted deltamethrin concentrations (20.1, 40.3, 80.6 and 161.3 ng L(-1)) were compared against control acetylcholinesterase activity. Our results showed that after 48 h of deltamethrin exposure, all treatments induced a significant decrease of AChE activities whatever the three considered strains. However, diverse responses were registered in terms of lowest observed effect concentrations (LOEC: 80.6 ng L(-1) for strain 1 and 20.1 ng L(-1) for strains 2 and 3) revealing differences in sensitivity among the three tested strains of D. magna. Our results suggest that after deltamethrin exposure, the AChE activity responses can be also used as a biomarker of susceptibility (i.e., variation of strain specific response). Moreover, our results show that strain 1 is the less sensitive in terms of IC50-48 h of AChE, whereas it became the most sensitive when considering the EC50-48 h estimated in the standard ecotoxicity test. Copyright © 2014 Elsevier Ltd. All rights reserved.

Inhibition of cholinesterase activity by extracts, fractions and compounds from Calceolaria talcana and C. integrifolia (Calceolariaceae: Scrophulariaceae).

Science.gov (United States)

Cespedes, Carlos L; Muñoz, Evelyn; Salazar, Juan R; Yamaguchi, Lydia; Werner, Enrique; Alarcon, Julio; Kubo, Isao

2013-12-01

Extracts, fractions and compounds from Calceolaria talcana and C. integrifolia exhibited strong inhibitory effects of the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes using the in vitro Ellman's method. The most active samples were from the ethyl acetate extract, which caused a mixed-type inhibition against AChE (69.8% and 79.5% at 100 and 200 μg/ml, respectively) and against BChE (98.5% and 99.8% at 100 and 200 μg/ml, respectively) and its major components verbascoside 8 (50.9% and 70.0% at 200 μg/ml, against AChE and BChE, respectively), martynoside 9, and fraction F-7 (which corresponds to a mixture of 8, 9, and other phenylethanoids and phenolics that remain unidentified) (80.2% and 85.3% at 100 and 200 μg/ml, against AChE, respectively and 99.1% and 99.7% at 100 and 200 μg/ml, against BChE, respectively) inhibited the acetylcholinesterase enzyme competitively. The most polar fraction F-5 from n-hexane extract (a mixture of naphthoquinones: 2-hydroxy-3-(1,1-dimethylallyl-1,4-naphthoquinone) 6, α-dunnione 7 and other polar compounds that remain unidentified) showed a mixed-type inhibition (71.5% and 72.1% against AChE and BChE at 200 μg/ml, respectively). Finally, the methanol-soluble residue presented a complex, mixed-type inhibition (39.9% and 67.9% against AChE and BChE at 200 μg/ml, respectively). The mixture F-3 with diterpenes was obtained from the n-hexane extract: (1,10-cyclopropyl-9-epi-ent-isopimarol) 1, 19-α-hydroxy-abietatriene 2, and F-4 a mixture of triterpenes α-lupeol 3, β-sitosterol 4, ursolic acid 5 together with a complex mixture of terpenes that did not show activity. In summary, extracts and natural compounds from C. talcana and C. integrifolia were isolated, identified and characterized as cholinesterase inhibitors.

Antioxidant and acetylcholinesterase inhibitory activities of ginger root (Zingiber officinale Roscoe) extract.

Science.gov (United States)

Tung, Bui Thanh; Thu, Dang Kim; Thu, Nguyen Thi Kim; Hai, Nguyen Thanh

2017-05-04

Background Zingiber officinale Roscoe has been used in traditional medicine for the treatment of neurological disorder. This study aimed to investigate the phenolic contents, antioxidant, acetylcholinesterase enzyme (AChE) inhibitory activities of different fraction of Z. officinale root grown in Vietnam. Methods The roots of Z. officinale are extracted with ethanol 96 % and fractionated with n-hexane, ethyl acetate (EtOAc) and butanol (BuOH) solvents. These fractions evaluated the antioxidant activity by 1,1-Diphenyl -2-picrylhydrazyl (DPPH) assay and AChE inhibitory activity by Ellman's colorimetric method. Results Our data showed that the total phenolic content of EtOAc fraction was highest equivalents to 35.2±1.4 mg quercetin/g of fraction. Our data also demonstrated that EtOAc fraction had the strongest antioxidant activity with IC50 was 8.89±1.37 µg/mL and AChE inhibitory activity with an IC50 value of 22.85±2.37 μg/mL in a dose-dependent manner, followed by BuOH fraction and the n-hexane fraction is the weakest. Detailed kinetic analysis indicated that EtOAc fraction was mixed inhibition type with Ki (representing the affinity of the enzyme and inhibitor) was 30.61±1.43 µg/mL. Conclusions Our results suggest that the EtOAc fraction of Z. officinale may be a promising source of AChE inhibitors for Alzheimer's disease.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Inhibition of Acetylcholinesterase and Fatty Acid Composition in Theobroma grandiflorum Seeds

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Casandra Valentina Itriago

2017-07-01

Full Text Available Theobroma grandiflorum is an important fruit tree from Sterculiaceae family, native to the Brazilian Amazon, known in the region as cupuaçu. The seeds have a high fat content (24% with characteristics that resemble those of cocoa (Theobroma cacao butter with potential applications in the cosmetic, pharmaceutical and food industries. The main objective of this work was to explore the seed fats from T. grandiflorum that were analyzed for fatty acid composition by Gas Chromatography with Flame Ionization Detector (GC-FID and to analyze their activity for acetylcholinesterase inhibition. Chromatographic analysis provided detection of nine fatty acids. The major fatty acids found in the species were oleic (40.0%, stearic (32.7%, arachidic (10.4% and palmitic (8.0%. The acetylcholinesterase inhibition by fats from seeds was over 40.48%. DOI: http://dx.doi.org/10.17807/orbital.v0i0.894 

Inhibition of Cholinesterases and Some Pro-Oxidant induced Oxidative Stress in Rats Brain by Two Tomato (Lycopersicon Esculentum) Varieties

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Oboh, G.; Bakare, O.O.; Ademosun, A.O.; Akinyemi, A.J.; Olasehinde, T.A.

2015-01-01

This study sought to investigate the effects of two tomato varieties [Lycopersicon esculentum Mill. var. esculentum (ESC) and Lycopersicon esculentum Mill. var. cerasiforme (CER)] on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities in vitro. Phenolics content, carotenoids characterisation, inhibition of Fe2+ and quinolinic acid-induced malondialdehyde (MDA) production in rats brain homogenate and NO* scavenging abilities were also assesed in addition to the AChE and BChE inhibition assays. There was no significant difference in the AChE inhibitory ability of the samples, while CER had significantly higher BChE inhibitory activity. Furthermore, the tomatoes inhibited Fe2+ and quinolinic acid-induced MDA production and further exhibited antioxidant activities through their NO* scavenging abilities. There was no significant difference in the phenolic content of the samples, while significantly high amounts of lycopene were detected in the tomatoes. The cholinesterase-inhibition and antioxidant properties of the “tomatoes” could make them good dietary means for the management of neurodegenerative disorders.

Chemical Composition and Acetylcholinesterase Inhibitory Activity of Essential Oils from Piper Species.

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Xiang, Cai-Peng; Han, Jia-Xin; Li, Xing-Cong; Li, Yun-Hui; Zhang, Yi; Chen, Lin; Qu, Yan; Hao, Chao-Yun; Li, Hai-Zhou; Yang, Chong-Ren; Zhao, San-Jun; Xu, Min

2017-05-10

The essential oils (EOs) derived from aromatic plants such as Piper species are considered to play a role in alleviating neuronal ailments that are associated with inhibition of acetylcholinesterase (AChE). The chemical compositions of 23 EOs prepared from 16 Piper spp. were analyzed by both gas chromatography with a flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). A total of 76 compounds were identified in the EOs from the leaves and stems of 19 samples, while 30 compounds were detected in the EOs from the fruits of four samples. Sesquiterpenes and phenylpropanoids were found to be rich in these EOs, of which asaricin, caryophyllene, caryophyllene oxide, isospathulenol, (+)-spathulenol, and β-bisabolene are the major constituents. The EOs from the leaves and stems of Piper austrosinense, P. puberulum, P. flaviflorum, P. betle, and P. hispidimervium showed strong AChE inhibitory activity with IC 50 values in the range of 1.51 to 13.9 mg/mL. A thin-layer chromatography (TLC) bioautography assay was employed to identify active compound(s) in the most active EO from P. hispidimervium. The active compound was isolated and identified as asaricin, which gave an IC 50 value of 0.44 ± 0.02 mg/mL against AChE, comparable to galantamine with an IC 50 0.15 ± 0.01 mg/mL.

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

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Lotta Berg

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

Design, synthesis and biological activity of novel donepezil derivatives bearing N-benzyl pyridinium moiety as potent and dual binding site acetylcholinesterase inhibitors.

Science.gov (United States)

Lan, Jin-Shuai; Zhang, Tong; Liu, Yun; Yang, Jing; Xie, Sai-Sai; Liu, Jing; Miao, Ze-Yang; Ding, Yue

2017-06-16

A series of new donepezil derivatives were designed synthesized and evaluated as multifunctional cholinesterase inhibitors against Alzheimer's disease (AD). In vitro studies showed that most of them exhibited significant potency to inhibit acetylcholinesterase and self-induced β-amyloid (Aβ) aggregation, and moderate antioxidant activity. Especially, compound 5b presented the greatest ability to inhibit cholinesterase (IC 50 , 1.9 nM for eeAChE and 0.8 nM for hAChE), good inhibition of Aβ aggregation (53.7% at 20 μM) and good antioxidant activity (0.54 trolox equivalents). Kinetic and molecular modeling studies indicated that compound 5b was a mixed-type inhibitor, binding simultaneously to the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE. In addition, compound 5b could reduce PC12 cells death induced by oxidative stress and Aβ (1-42). Moreover, in vivo experiments showed that compound 5b was nontoxic and tolerated at doses up to 2000 mg/kg. These results suggested that compound 5b might be an excellent multifunctional agent for AD treatment. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Acetylcholinesterase and butyrylcholinesterase inhibitory activity of some selected Nigerian medicinal plants

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Taiwo O. Elufioye

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.

Donepezil prevents RANK-induced bone loss via inhibition of osteoclast differentiation by downregulating acetylcholinesterase

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Tsuyoshi Sato

2015-09-01

Conclusions: AChE promotes osteoclast differentiation in vitro. Donepezil inhibits osteoclast function in vitro and prevents bone loss by suppressing bone resorption in vivo, suggesting the possibility that donepezil reduces fracture risk in patients with Alzheimer's disease.

Toxicological and biochemical characterizations of AChE in phosalone-susceptible and resistant populations of the common pistachio psyllid, Agonoscena pistaciae

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Alizadeh, Ali; Talebi-Jahromi, Khalil; Hosseininaveh, Vahid; Ghadamyari, Mohammad

2014-01-01

Abstract The toxicological and biochemical characteristics of acetylcholinesterases (AChE) in nine populations of the common pistachio psyllid, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Psyllidae), were investigated in Kerman Province, Iran. Nine A. pistaciae populations were collected from pistachio orchards, Pistacia vera L. (Sapindales: Anacardiaceae), located in Rafsanjan, Anar, Bam, Kerman, Shahrbabak, Herat, Sirjan, Pariz, and Paghaleh regions of Kerman province. The previous bioassay results showed these populations were susceptible or resistant to phosalone, and the Rafsanjan population was most resistant, with a resistance ratio of 11.3. The specific activity of AChE in the Rafsanjan population was significantly higher than in the susceptible population (Bam). The affinity ( KM ) and hydrolyzing efficiency ( Vmax ) of AChE on acetylthiocholine iodide, butyrylthiocholine iodide, and propionylthiocholine odide as artificial substrates were clearly lower in the Bam population than that in the Rafsanjan population. These results indicated that the AChE of the Rafsanjan population had lower affinity to these substrates than that of the susceptible population. The higher Vmax value in the Rafsanjan population compared to the susceptible population suggests a possible over expression of AChE in the Rafsanjan population. The in vitro inhibitory effect of several organophosphates and carbamates on AChE of the Rafsanjan and Bam populations was determined. Based on I50, the results showed that the ratios of AChE insensitivity of the resistant to susceptible populations were 23 and 21.7-fold to monocrotophos and phosphamidon, respectively. Whereas, the insensitivity ratios for Rafsanjan population were 0.86, 0.8, 0.78, 0.46, and 0.43 for carbaryl, eserine, propoxur, m-tolyl methyl carbamate, and carbofuran, respectively, suggesting negatively correlated sensitivity to organophosphate-insensitive AChE. Therefore, AChE from the Rafsanjan population showed

Two Bombyx mori acetylcholinesterase genes influence motor control and development in different ways

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Among its other biological roles, acetylcholinesterase (AChE, EC 3.1.1.7), encoded by two ace genes in most insects, catalyses the breakdown of acetylcholine, thereby terminating synaptic transmission. ace1 encodes the synaptic enzyme and ace2 has other essential actions in many insect species, such...

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

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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.

Ebselen inhibits the activity of acetylcholinesterase globular isoform G4 in vitro and attenuates scopolamine-induced amnesia in mice.

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Martini, Franciele; Pesarico, Ana P; Brüning, César A; Zeni, Gilson; Nogueira, Cristina W

2018-02-05

There is a well-known relationship between the cholinergic system and learning, memory, and other common cognitive processes. The process for researching and developing new drugs has lead researchers to repurpose older ones. This study investigated the effects of ebselen on the activity of acethylcholinesterase (AChE) isoforms in vitro and in an amnesia model induced by scopolamine in Swiss mice. In vitro, ebselen at concentrations equal or higher than 10 μM inhibited the activity of cortical and hippocampal G4/AChE, but not G1/AChE isoform. Treatment of mice with ebselen (50 mg/kg, i.p.) was effective against impairment of spatial recognition memory in both Y-maze and novel object recognition tests induced by scopolamine (1 mg/kg, i.p.). Ebselen (50 mg/kg) inhibited hippocampal AChE activity in mice. The present study demonstrates that ebselen inhibited the G4/AChE isoform in vitro and elicited an anti-amnesic effect in a mouse model induced by scopolamine. These findings reveal ebselen as a potential compound in terms of opening up valid therapeutic avenues for the treatment of memory impairment diseases. © 2018 Wiley Periodicals, Inc.

Catalytic soman scavenging by Y337A/F338A acetylcholinesterase mutant assisted with novel site-directed aldoximes

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Kovarik, Zrinka; Hrvat, Nikolina Maček; Katalinić, Maja; Sit, Rakesh K.; Paradyse, Alexander; Žunec, Suzana; Musilek, Kamil; Fokin, Valery V.; Taylor, Palmer; Radić, Zoran

2016-01-01

Exposure to the nerve agent soman is difficult to treat due to the rapid dealkylation of soman-acetylcholinesterase (AChE) conjugate known as aging. Oxime antidotes commonly used to reactivate organophosphate inhibited AChE are ineffective against soman, while the efficacy of the recommended nerve agent bioscavenger butyrylcholinesterase is limited by strictly stoichiometric scavenging. To overcome this limitation, we tested ex vivo, in human blood, and in vivo, in soman exposed mice, the capacity of aging-resistant human AChE mutant Y337A/F338A in combination with oxime HI-6 to act as a catalytic bioscavenger of soman. HI-6 was previously shown in vitro to efficiently reactivate this mutant upon soman, as well as VX, cyclosarin, sarin and paraoxon inhibition. We here demonstrate that ex vivo, in whole human blood, 1 μM soman was detoxified within 30 minutes when supplemented with 0.5 μM Y337A/F338A AChE and 100 μM HI-6. This combination was further tested in vivo. Catalytic scavenging of soman in mice improved the therapeutic outcome and resulted in the delayed onset of toxicity symptoms. Furthermore, in a preliminary in vitro screen we identified an even more efficacious oxime than HI-6, in a series of forty-two pyridinium aldoximes, and five imidazole 2-aldoxime N-propyl pyridinium derivatives. One of the later imidazole aldoximes, RS-170B, was a 2–3 –fold more effective reactivator of Y337A/F338A AChE than HI-6 due to the smaller imidazole ring, as indicated by computational molecular models, that affords a more productive angle of nucleophilic attack. PMID:25835984

Acetylcholinesterase inhibition by somes promising Brazilian medicinal plants.

Science.gov (United States)

Feitosa, C M; Freitas, R M; Luz, N N N; Bezerra, M Z B; Trevisan, M T S

2011-08-01

A microplate assay and a thin-layer chromatography (TLC) "in situ" assay based on the Ellman assay was used to screen for acetylcholinesterase inhibitors from ethyl acetate and methanol extracts of Brazilian medicinal plants of families that, according to the literature, have traditional uses that might be connected with acetylcholinesterase inhibition. Eighteen species belonging to Convolvulaceae, Crassulaceae, Euphorbiaceae, Leguminosae, Malvaceae, Moraceae, Nyctaginaceae and Rutaceae families were tested. The most active plants were Ipomoea asarifolia (IC50 = 0.12 mg/mL), Jatropha curcas (IC50 = 0.25 mg/mL), Jatropha gossypiifolia (IC50 = 0.05 mg/mL), Kalanchoe brasiliensis (IC50 = 0.16 mg/mL) and Senna alata (IC50 = 0.08 mg/mL). The most promising extracts were the Jatropha gossypiifolia and Senna alata species assuming there were compounds with a similar activity to galanthamine, which should contain about 1% of an active compound, or if present at lower levels even more active compounds than galanthamine (IC50 = 0.37 x 10-3 mg/mL) should be present.

Acetylcholinesterase inhibition by somes promising Brazilian medicinal plants

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CM. Feitosa

Full Text Available A microplate assay and a thin-layer chromatography (TLC "in situ" assay based on the Ellman assay was used to screen for acetylcholinesterase inhibitors from ethyl acetate and methanol extracts of Brazilian medicinal plants of families that, according to the literature, have traditional uses that might be connected with acetylcholinesterase inhibition. Eighteen species belonging to Convolvulaceae, Crassulaceae, Euphorbiaceae, Leguminosae, Malvaceae, Moraceae, Nyctaginaceae and Rutaceae families were tested. The most active plants were Ipomoea asarifolia (IC50 = 0.12 mg/mL, Jatropha curcas (IC50 = 0.25 mg/mL, Jatropha gossypiifolia (IC50 = 0.05 mg/mL, Kalanchoe brasiliensis (IC50 = 0.16 mg/mL and Senna alata (IC50 = 0.08 mg/mL. The most promising extracts were the Jatropha gossypiifolia and Senna alata species assuming there were compounds with a similar activity to galanthamine, which should contain about 1% of an active compound, or if present at lower levels even more active compounds than galanthamine (IC50 = 0.37 x 10-3 mg/mL should be present.

Essential oil from lemon peels inhibit key enzymes linked to neurodegenerative conditions and pro-oxidant induced lipid peroxidation.

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Oboh, Ganiyu; Olasehinde, Tosin A; Ademosun, Ayokunle O

2014-01-01

This study sought to investigate the effects of essential oil from lemon (Citrus limoni) peels on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities in vitro. The essential oil was extracted by hydrodistillation, dried with anhydrous Na2SO4 and characterized using gas chromatography. Antioxidant properties of the oil and inhibition of pro-oxidant-induced lipid peroxidation in rats brain homogenate were also assessed. The essential oil inhibited AChE and BChE activities in a concentration-dependent manner. GC analysis revealed the presence of sabinene, limonene, α-pinene, β-pinene, neral, geranial, 1,8-cineole, linalool, borneol, α-terpineol, terpinen-4-ol, linalyl acetate and β-caryophyllene. Furthermore, the essential oil exhibited antioxidant activities as typified by ferric reducing property, Fe(2+)-chelation and radicals [DPPH, ABTS, OH, NO] scavenging abilities. The inhibition of AChE and BChE activities, inhibition of pro-oxidant induced lipid peroxidation and antioxidant activities could be possible mechanisms for the use of the essential oil in the management and prevention of oxidative stress-induced neurodegeneration.

Phytochemical Quantification and the In Vitro Acetylcholinesterase Inhibitory Activity of Phellodendron chinense and Its Components.

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Kim, Yu Jin; Lim, Hye-Sun; Kim, Yoonju; Lee, Jun; Kim, Bu-Yeo; Jeong, Soo-Jin

2017-06-02

The dried bark of Phellodendron chinense has been used as a traditional herbal medicine to remove damp heat, relieve consumptive fever, and cure dysentery and diarrhea. In the present study, we performed quantitative analyses of the two components of P. chinense , phellodendrine and berberine, using high-performance liquid chromatography. A 70% ethanol extract of P. chinense was prepared and the two components were separated on a C-18 analytical column using a gradient solvent system of acetonitrile and 0.1% ( v / v ) aqueous trifluoroacetic acid. The ultraviolet wavelength used for detection was 200 nm for phellodendrine and 226 nm for berberine. The analytical method established here showed high linearity (correlation coefficient, ≥0.9991). The amount of phellodendrine and berberine used was 22.255 ± 0.123 mg/g and 269.651 ± 1.257 mg/g, respectively. Moreover, we performed an in vitro acetylcholinesterase (AChE) activity assay and an amyloid-β aggregation test to examine the biological properties of phellodendrine and berberine as therapeutic drugs for Alzheimer's disease. Phellodendrine and berberine inhibited AChE activity in a dose-dependent manner (IC 50 = 36.51 and 0.44 μM, respectively). In contrast, neither phellodendrine nor berberine had an effect on amyloid-β aggregation. The P. chinense extract and phellodendrine, but not berberine, exhibited antioxidant activity by increasing radical scavenging activity. Moreover, P. chinense demonstrated a neuroprotective effect in hydrogen peroxide-treated HT22 hippocampal cells. Overall, our findings suggest that P. chinense has potential as an anti-Alzheimer's agent via the suppression of the enzymatic activity of acetylcholinesterase and the stimulation of antioxidant activity.

Avoidance behaviour response and esterase inhibition in the earthworm, Lumbricus terrestris, after exposure to chlorpyrifos.

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Martínez Morcillo, S; Yela, J L; Capowiez, Y; Mazzia, C; Rault, M; Sanchez-Hernandez, Juan C

2013-05-01

The avoidance response of earthworms to polluted soils has been standardised using a simple and low-cost test, which facilitates soil toxicity screening. In this study, the avoidance response of Lumbricus terrestris was quantified in chlorpyrifos-spiked soils, depending on the pesticide concentration and exposure duration. The inhibition of acetylcholinesterase (AChE) and carboxylesterase (CbE) activities was also determined as indirect measures of pesticide bioavailability. The effects of different chlorpyrifos concentrations were examined in a standardised test (two-chamber system) with 0.6, 3 and 15 mg/kg chlorpyrifos. A modification of the test involved a pre-exposure step (24, 48 or 72 h) in soils spiked with 15 mg/kg. In both protocols, earthworms were unable to avoid the contaminated soils. However, the esterase activities showed that all earthworms were exposed to chlorpyrifos. Acetylcholinesterase activity did not change in earthworms in the standardised behavioural test (0.58 ± 0.20 U/mg protein, mean ± SD; n = 72), whereas the CbE activity was significantly inhibited (62-87 % inhibition) in earthworms exposed to 3 and 15 mg/kg. In the modified test, earthworms had greatly inhibited AChE activity (0.088 ± 0.034 U/mg protein, n = 72), which was supported by reactivation of the inhibited enzyme activity in the presence of pralidoxime (2-PAM). Similarly, the CbE activity was significantly inhibited in earthworms with all treatments. This study suggests that the avoidance behaviour test for organophosphorus-contaminated soils could be supported by specific biomarkers to facilitate a better understanding of pesticide exposure and toxicity during this test.

DNA damage, acetylcholinesterase activity and lysosomal stability in native and transplanted mussels (Mytilus edulis) in areas close to coastal chemical dumping sites in Denmark

DEFF Research Database (Denmark)

Rank, J.; Lehtonen, K. K.; Strand, J.

2007-01-01

of chemical pollution complex, as seen especially in the variability in results on DNA damage, and also in regard to AChE activity. These investigations further stress the importance of understanding the effects of natural factors (salinity, temperature, water levels, rain and storm events) in correct......Biomarkers of genotoxicity (DNA damage, measured as tail moment in the Comet assay), neurotoxicity (acetylcholinesterase inhibition, AChE) and general stress (lysosomal membrane stability, LMS) were studied in native and transplanted blue mussels (Mytilus edulis) in coastal areas of western Denmark...... potentially affected by anthropogenic pollution originating from chemical dumping sites. The results indicate responses to pollution in all the biomarkers applied at the suspected areas, but the results were not consistent. Seasonal fluctuations in exposure situations at the study sites make interpretation...

Toxicodynamic analysis of the inhibition of isolated human acetylcholinesterase by combinations of methamidophos and methomyl in vitro

International Nuclear Information System (INIS)

Bosgra, Sieto; Eijkeren, Jan C.H. van; Schans, Marcel J. van der; Langenberg, Jan P.; Slob, Wout

2009-01-01

The applicability of dose addition to combinations of OP-esters and carbamates has been questioned based on theoretical considerations, but these have not been well supported by experimental findings. In the present study, the inhibition of AChE by combinations of methamidophos (an OP-ester) and methomyl (a carbamate) was examined in vitro. AChE inhibition was measured by the Ellman assay. We addressed the question of interaction between the OP-ester and carbamate by a toxicodynamic (TD) model reflecting the mechanism of action of the individual chemicals, without incorporating any interactions between them. The model was extended by including the experimental actions in the Ellman assay to correct for the difference in reactivation rates between phosphorylated and carbamylated AChE, which caused a bias in the observations from the assay. This zero-interactive TD model described the observations well, indicating that the OP-ester and carbamate did not interact. The applicability of dose addition was further explored by applying dose addition to the predicted inhibition by the TD model. Despite the differences in dynamics between methamidophos and methomyl, their dose-response curves were close to parallel, and dose addition gave a reasonably accurate prediction of the combined effects

Rapid Screening of Acetylcholinesterase Inhibitors by Effect-Directed Analysis Using LC × LC Fractionation, a High Throughput in Vitro Assay, and Parallel Identification by Time of Flight Mass Spectrometry.

Science.gov (United States)

Ouyang, Xiyu; Leonards, Pim E G; Tousova, Zuzana; Slobodnik, Jaroslav; de Boer, Jacob; Lamoree, Marja H

2016-02-16

Effect-directed analysis (EDA) is a useful tool to identify bioactive compounds in complex samples. However, identification in EDA is usually challenging, mainly due to limited separation power of the liquid chromatography based fractionation. In this study, comprehensive two-dimensional liquid chromatography (LC × LC) based microfractionation combined with parallel high resolution time of flight (HR-ToF) mass spectrometric detection and a high throughput acetylcholinesterase (AChE) assay was developed. The LC × LC fractionation method was validated using analytical standards and a C18 and pentafluorophenyl (PFP) stationary phase combination was selected for the two-dimensional separation and fractionation in four 96-well plates. The method was successfully applied to identify AChE inhibitors in a wastewater treatment plant (WWTP) effluent. Good orthogonality (>0.9) separation was achieved and three AChE inhibitors (tiapride, amisulpride, and lamotrigine), used as antipsychotic medicines, were identified and confirmed by two-dimensional retention alignment as well as their AChE inhibition activity.

An amperometric biosensor based on acetylcholinesterase immobilized onto iron oxide nanoparticles/multi-walled carbon nanotubes modified gold electrode for measurement of organophosphorus insecticides

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Chauhan, Nidhi [Department of Biochemistry, M.D. University, Rohtak 124001, Haryana (India); Pundir, Chandra Shekhar, E-mail: pundircs@rediffmail.com [Department of Biochemistry, M.D. University, Rohtak 124001, Haryana (India)

2011-09-02

Graphical abstract: The stepwise amperometric biosensor fabrication process and immobilized acetylcholinesterase inhibition in pesticide solution. Highlights: {center_dot} Constructed a novel composite material using Fe{sub 3}O{sub 4}NP and c-MWCNT at Au electrode for electrocatalysis. {center_dot} The properties of nanoparticles modified electrodes were studied by SEM, FTIR, CVs and EIS. {center_dot} The biosensor exhibited good sensitivity (0.475 mA {mu}M{sup -1}) {center_dot} The half life of electrode was 2 months. {center_dot} The sensor was suitable for trace detection of OP pesticide residues in milk and water. - Abstract: An acetylcholinesterase (AChE) purified from maize seedlings was immobilized covalently onto iron oxide nanoparticles (Fe{sub 3}O{sub 4}NP) and carboxylated multi walled carbon nanotubes (c-MWCNT) modified Au electrode. An organophosphorus (OP) biosensor was fabricated using this AChE/Fe{sub 3}O{sub 4}/c-MWCNT/Au electrode as a working electrode, Ag/AgCl as standard and Pt wire as an auxiliary electrode connected through a potentiostat. The biosensor was based on inhibition of AChE by OP compounds/insecticides. The properties of nanoparticles modified electrodes were studied by scanning electron microscopy (SEM), Fourier transform infrared (FTIR), cyclic voltammograms (CVs) and electrochemical impedance spectroscopy (EIS). The synergistic action of Fe{sub 3}O{sub 4}NP and c-MWCNT showed excellent electrocatalytic activity at low potential (+0.4 V). The optimum working conditions for the sensor were pH 7.5, 35 deg. C, 600 {mu}M substrate concentration and 10 min for inhibition by pesticide. Under optimum conditions, the inhibition rates of OP pesticides were proportional to their concentrations in the range of 0.1-40 nM, 0.1-50 nM, 1-50 nM and 10-100 nM for malathion, chlorpyrifos, monocrotophos and endosulfan respectively. The detection limits were 0.1 nM for malathion and chlorpyrifos, 1 nM for monocrotophos and 10 nM for endosulfan. The

Methyl jasmonate enhances memory performance through inhibition of oxidative stress and acetylcholinesterase activity in mice.

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Eduviere, Anthony T; Umukoro, S; Aderibigbe, Adegbuyi O; Ajayi, Abayomi M; Adewole, Folashade A

2015-07-01

Current research effort focuses on the development of safer natural compounds with multipronged mechanisms of action that could be used to ameliorate memory deficits in patients with Alzheimer's disease, as cure for the disease still remains elusive. In this study, we evaluated the effect of methyl jasmonate (MJ), a naturally occurring bioactive compound on memory, acetylcholinesterase activity and biomarkers of oxidative stress in mice. Male Swiss mice were treated with intraperitoneal injection of MJ (10-40 mg/kg) alone or in combination with scopolamine (3mg/kg) once daily for 7 days. Thirty minutes after the last treatment, memory functions were assessed using Y-maze and object recognition tests. Thereafter, acetylcholinesterase activity and levels of biomarkers of oxidative stress were assessed in mice brains using standard biochemical procedures. MJ significantly enhanced memory performance and reversed scopolamine-induced cognitive impairment in mice. MJ demonstrated significant inhibition of acetylcholinesterase activity suggesting increased cholinergic neurotransmission. It further decreased malondialdehyde concentrations in mouse brain indicating antioxidant activity. Moreover, MJ significantly increased glutathione levels and activity of antioxidant enzymes (catalase and superoxide dismutase) in mice brains. The increased oxidative stress; evidenced by elevated levels of malondialdehyde and decreased antioxidant defense systems in scopolamine-treated mice was attenuated by MJ. The results of this study suggest that MJ may be useful in conditions associated with memory dysfunctions or age-related cognitive decline. The positive effect of MJ on memory may be related to inhibition of oxidative stress and enhancement of cholinergic neurotransmission through inhibition of acetylcholinesterase activity. Copyright © 2015 Elsevier Inc. All rights reserved.

Synthesis and biological evaluation of lycorine derivatives as dual inhibitors of human acetylcholinesterase and butyrylcholinesterase

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Wang Yue-Hu

2012-09-01

Full Text Available Abstract Background Alzheimer’s disease (AD is a neurologically degenerative disorder that affects more than 20 million people worldwide. The selective butyrylcholinesterase (BChE inhibitors and bivalent cholinesterase (ChE inhibitors represent new treatments for AD. Findings A series of lycorine derivatives (1–10 were synthesized and evaluated for anti-cholinesterase activity. Result showed that the novel compound 2-O-tert-butyldimethylsilyl-1-O-(methylthiomethyllycorine (7 was a dual inhibitor of human acetylcholinesterase (hAChE and butyrylcholinesterase (hBChE with IC50 values of 11.40 ± 0.66 μM and 4.17 ± 0.29 μM, respectively. The structure-activity relationships indicated that (i the 1-O-(methylthiomethyl substituent in lycorine was better than the 1-O-acetyl group for the inhibition of cholinesterase; (ii the acylated or etherified derivatives of lycorine and lycorin-2-one were more potent against hBChE than hAChE; and (iii the oxidation of lycorine at C-2 decreases the activity. Conclusion Acylated or etherified derivatives of lycorine are potential dual inhibitors of hBChE and hAChE. Hence, further study on the modification of lycorine for ChE inhibition is necessary.

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

Energy Technology Data Exchange (ETDEWEB)

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

1999-05-01

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

Role of aqueous extract of Cynodon dactylon in prevention of carbofuran- induced oxidative stress and acetylcholinesterase inhibition in rat brain.

Science.gov (United States)

Rai, D K; Sharma, R K; Rai, P K; Watal, G; Sharma, B

2011-02-12

The present study was designed to investigate the ameliorating effect of aqueous extract of C. dactylon on carbofuran induced oxidative stress (OS) and alterations in the activity of acetylcholinesterase (AChE) in the brain of rats. Vitamin C was used as a positive control. Wistar rats were administered with single sub-acute oral dose (1.6 mgkg-1 b.wt.) of carbofuran for 24 h. The OS parameters such as lipid peroxidation (LPO) and the activities of antioxidant enzymes including super oxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST), and that of AChE were studied in brain. Carbofuran treatment significantly increased the activities of SOD and CAT by 75 and 60%, respectively. It also induced the level of LPO by 113%. In contrast, the activities of GST and AChE were recorded to be diminished by 25 and 33%, respectively. Pretreatment of the rats with aqueous extract of C. dactylon (oral; 500mgkg-1) restored SOD activity completely but CAT activity only partially (7%). Carbofuran induced LPO was moderated by 95% in the brain of C. dactylon treated rats. The observed changes in OS parameters in C. dactylon treated group were comparable to that observed in vitamin C (200 mg-kg-1 b. wt.) treated group. Surprisingly, C. dactylon treatment significantly recovered the activity of AChE to a similar level as observed in the brain of control group. In contrast vitamin C treatment did not cause significant change in the activity of AChE in carbofuran treated group. There were no noticeable changes in the aforementioned study parameters in the brain of rats receiving C. dactylon and vitamin C, only. The results suggest that the study is extremely important in the context of development of new anticholinestesterase and antioxidant antidotes against carbofuran from C. dactylon.

Altered levels of acetylcholinesterase in Alzheimer plasma.

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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.

Chlorpyrifos and Malathion have opposite effects on behaviors and brain size that are not correlated to changes in AChE activity

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Richendrfer, Holly; Creton, Robbert

2015-01-01

Organophosphates, a type of neurotoxicant pesticide, are used globally for the treatment of pests on croplands and are therefore found in a large number of conventional foods. These pesticides are harmful and potentially deadly if ingested or inhaled in large quantities by causing a significant reduction in acetylcholinesterase (AChE) activity in the central and peripheral nervous system. However, much less is known about the effects of exposure to small quantities of the pesticides on neural systems and behavior during development. In the current study we used zebrafish larvae in order to determine the effects of two of the most widely used organophosphates, chlorpyrifos and malathion, on zebrafish behavior and AChE activity. Embryos and larvae were exposed to the organophosphates during different time points in development and then tested at 5 days post-fertilization for behavioral, neurodevelopmental and AChE abnormalities. The results of the study indicate that chlorpyrifos and malathion cause opposing behaviors in the larvae such as swim speed (hypoactivity vs. hyperactivity) and rest. Additionally, the pesticides affect only certain behaviors, such as thigmotaxis, during specific time points in development that are unrelated to changes in AChE activity. Larvae treated with malathion but not chlorpyrifos also had significantly smaller forebrain and hindbrain regions compared to controls by 5 days post-fertilization. We conclude that exposure to very low concentrations of organophosphate pesticides during development cause abnormalities in behavior and brain size. PMID:25983063

Chlorpyrifos and malathion have opposite effects on behaviors and brain size that are not correlated to changes in AChE activity.

Science.gov (United States)

Richendrfer, Holly; Creton, Robbert

2015-07-01

Organophosphates, a type of neurotoxicant pesticide, are used globally for the treatment of pests on croplands and are therefore found in a large number of conventional foods. These pesticides are harmful and potentially deadly if ingested or inhaled in large quantities by causing a significant reduction in acetylcholinesterase (AChE) activity in the central and peripheral nervous system. However, much less is known about the effects of exposure to small quantities of the pesticides on neural systems and behavior during development. In the current study we used zebrafish larvae in order to determine the effects of two of the most widely used organophosphates, chlorpyrifos and malathion, on zebrafish behavior and AChE activity. Embryos and larvae were exposed to the organophosphates during different time points in development and then tested at 5 days post-fertilization for behavioral, neurodevelopmental and AChE abnormalities. The results of the study indicate that chlorpyrifos and malathion cause opposing behaviors in the larvae such as swim speed (hypoactivity vs. hyperactivity) and rest. Additionally, the pesticides affect only certain behaviors, such as thigmotaxis, during specific time points in development that are unrelated to changes in AChE activity. Larvae treated with malathion but not chlorpyrifos also had significantly smaller forebrain and hindbrain regions compared to controls by 5 days post-fertilization. We conclude that exposure to very low concentrations of organophosphate pesticides during development cause abnormalities in behavior and brain size. Copyright © 2015 Elsevier Inc. All rights reserved.

The application of HPLC with on-line coupled UV/MS-biochemical detection for isolation of an acetylcholinesterase inhibitor from Narcissus 'Sir Winston Churchill'

NARCIS (Netherlands)

Ingkaninan, K.; Hazekamp, A.; de Best, C.M.; Irth, H.; Tjaden, U.R.; van der Heijden, R.; van der Greef, J.; Verpoorte, R.

2000-01-01

An HPLC with on-line coupled UV/MS-biochemical detection method for acetylcholinesterase (AChE) inhibitors in natural sources has been developed. The potential of this method is shown by the isolation of a new AChE inhibitor from the alcoholic extract of Narcissus 'Sir Winston Churchill'. Combining

Rosuvastatin ameliorates cognitive impairment in rats fed with high-salt and cholesterol diet via inhibiting acetylcholinesterase activity and amyloid beta peptide aggregation.

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Husain, I; Akhtar, M; Abdin, M Zainul; Islamuddin, M; Shaharyar, M; Najmi, A K

2018-04-01

Amyloid beta (Aβ) peptide aggregation and cholinergic neurodegeneration are involved in the development of cognitive impairment. Therefore, in this article, we examined rosuvastatin (RSV), an oral hypolipidemic drug, to determine its potential as a dual inhibitor of acetylcholinesterase (AChE) and Aβ peptide aggregation for the treatment of cognitive impairment. Molecular docking study was done to examine the affinity of RSV with Aβ 1-42 and AChE in silico. We also employed neurobehavioral activity tests, biochemical estimation, and histopathology to study the anti-Aβ 1-42 aggregation capability of RSV in vivo. Molecular docking study provided evidence that RSV has the best binding conformer at its receptor site or active site of an enzyme. The cognitive impairment in female Wistar rats was induced by high-salt and cholesterol diet (HSCD) ad libitum for 8 weeks. RSV ameliorated serum cholesterol level, AChE activity, and Aβ 1-42 peptide aggregations in HSCD induced cognitive impairment. In addition, RSV-treated rats showed greater scores in the open field (locomotor activity) test. Moreover, the histopathological studies in the hippocampus and cortex of rat brain also supported that RSV markedly reduced the cognitive impairment and preserved the normal histoarchitectural pattern of the hippocampus and cortex. Taken together, these data indicate that RSV may act as a dual inhibitor of AChE and Aβ 1-42 peptide aggregation, therefore suggesting a therapeutic strategy for cognitive impairment treatment.

Novel coumarin derivatives bearing N-benzyl pyridinium moiety: potent and dual binding site acetylcholinesterase inhibitors.

Science.gov (United States)

Alipour, Masoumeh; Khoobi, Mehdi; Foroumadi, Alireza; Nadri, Hamid; Moradi, Alireza; Sakhteman, Amirhossein; Ghandi, Mehdi; Shafiee, Abbas

2012-12-15

A novel series of coumarin derivatives linked to benzyl pyridinium group were synthesized and biologically evaluated as inhibitors of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The enzyme inhibitory activity of synthesized compounds was measured using colorimetric Ellman's method. It was revealed that compounds 3e, 3h, 3l, 3r and 3s have shown higher activity compared with donepezil hydrochloride as standard drug. Most of the compounds in these series had nanomolar range IC(50) in which compound 3r (IC(50) = 0.11 nM) was the most active compound against acetylcholinesterase enzyme. Copyright © 2012 Elsevier Ltd. All rights reserved.

Dihydroagarofuranoid Sesquiterpenes as Acetylcholinesterase Inhibitors from Celastraceae Plants: Maytenus disticha and Euonymus japonicus.

Science.gov (United States)

Alarcón, Julio; Cespedes, Carlos L; Muñoz, Evelyn; Balbontin, Cristian; Valdes, Francisco; Gutierrez, Margarita; Astudillo, Luis; Seigler, David S

2015-12-02

Natural cholinesterase inhibitors have been found in many biological sources. Nine compounds with agarofuran (epoxyeudesmane) skeletons were isolated from seeds and aerial parts of Maytenus disticha and Euonymus japonicus. The identification and structural elucidation of compounds were based on spectroscopic data analyses. All compounds had inhibitory acetylcholinesterase (AChE) activity. These natural compounds, which possessed mixed or uncompetitive mechanisms of inhibitory activity against AChE, may be considered as models for the design and development of new naturally occurring drugs for management strategies for neurodegenerative diseases. This is the first report of these chemical structures for seeds of M. disticha.

Inhibition pathways of the potent organophosphate CBDP with cholinesterases revealed by X-ray crystallographic snapshots and mass spectrometry

International Nuclear Information System (INIS)

Carletti, Eugenie; Santoni, Gianluca; Colletier, Jacques-Philippe; Schopfer, Lawrence M.; Lockridge, Oksana; Masson, Patrick; Nachon, Florian; Weik, Martin

2013-01-01

Tri-o-cresyl-phosphate (TOCP) is a common additive in jet engine lubricants and hydraulic fluids suspected to have a role in aero-toxic syndrome in humans. TOCP is metabolized to cresyl saligenin phosphate (CBDP), a potent irreversible inhibitor of butyrylcholinesterase (BChE), a natural bio-scavenger present in the bloodstream, and acetylcholinesterase (AChE), the off-switch at cholinergic synapses. Mechanistic details of cholinesterase (ChE) inhibition have, however, remained elusive. Also, the inhibition of AChE by CBDP is unexpected, from a structural standpoint, i.e., considering the narrowness of AChE active site and the bulkiness of CBDP. In the following, we report on kinetic X-ray crystallography experiments that provided 2.7-3.3 Angstroms snapshots of the reaction of CBDP with mouse AChE and human BChE. The series of crystallographic snapshots reveals that AChE and BChE react with the opposite enantiomers and that an induced-fit rearrangement of Phe297 enlarges the active site of AChE upon CBDP binding. Mass spectrometry analysis of aging in either H 2 16 O or H 2 18 O furthermore allowed us to identify the inhibition steps, in which water molecules are involved, thus providing insights into the mechanistic details of inhibition. X-ray crystallography and mass spectrometry show the formation of an aged end product formed in both AChE and BChE that cannot be reactivated by current oxime-based therapeutics. Our study thus shows that only prophylactic and symptomatic treatments are viable to counter the inhibition of AChE and BChE by CBDP. (authors)

Antioxidant and Acetylcholinesterase Inhibiting Activity of Several Aqueous Tea Infusions in vitro

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Višnja Katalinić

2008-01-01

Full Text Available A study of antioxidant activity and acetylcholineste ase (AChE inhibitory activity of aqueous tea infusions prepared from walnut (Juglans regia L., peppermint (Mentha×piperita L., strawberry (Fragaria×ananassa L., lemon balm (Melissa officinalis L., sage (Salvia officinalis L., and immortelle (Helichrysum arenarium (L. Moench. is presented here. Chemical composition of selected aqueous tea infusions was determined by high-performance liquid chromatography with photodiode-array method (HPLC-PDA, and the following phenolic compounds were identified as dominant: rosmarinic acid, gallic acid (not identified in walnut and sage, caffeic acid (in sage and peppermint, neochlorogenic acid, 3-p-coumaroylquinic acid and quercetin 3-galactoside (in walnut and luteolin 7-O-glucoside (in sage. Antioxidant activity of the selected aqueous tea infusions was measured using low-density lipoprotein (LDL oxidation method, 2,2'-diphenyl-1-picrylhydrazyl (DPPH radical scavenging test, β-carotene bleaching method, and Rancimat method (induction period of lard oxidation. Strawberry and lemon balm aqueous infusions completely inhibited LDL oxidation at the concentration of 0.005 g/L in the reacting system. Very long prolongation of the lag phase was achieved with peppermint and sage aqueous infusions. All tested infusions in the concentration range of 0.05–2.85 g/L showed very pronounced effect of DPPH scavenging activity (90–100 % as well as the inhibition of β-carotene bleaching (89–100 %. In pure lipid medium, used in Rancimat method, sage and immortelle at the concentration of 0.16 % (by mass had the highest ability to inhibit lipid peroxidation process. Screening of the AChE inhibitory activity by Ellman´s method showed that the strongest inhibition was obtained with walnut and strawberry aqueous infusions at the concentration of 1.36 g/L in the reacting system. The presented results suggest that natural antioxidants could be useful and merit further

Identification of Potential Herbal Inhibitor of Acetylcholinesterase Associated Alzheimer’s Disorders Using Molecular Docking and Molecular Dynamics Simulation

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Chandrabhan Seniya

2014-01-01

Full Text Available Cholinesterase inhibitors (ChE-Is are the standard for the therapy of AD associated disorders and are the only class of approved drugs by the Food and Drug Administration (FDA. Additionally, acetylcholinesterase (AChE is the target for many Alzheimer’s dementia drugs which block the function of AChE but have some side effects. Therefore, in this paper, an attempt was made to elucidate cholinesterase inhibition potential of secondary metabolite from Cannabis plant which has negligible or no side effect. Molecular docking of 500 herbal compounds, against AChE, was performed using Autodock 4.2 as per the standard protocols. Molecular dynamics simulations have also been carried out to check stability of binding complex in water for 1000 ps. Our molecular docking and simulation have predicted high binding affinity of secondary metabolite (C28H34N2O6 to AChE. Further, molecular dynamics simulations for 1000 ps suggest that ligand interaction with the residues Asp72, Tyr70-121-334, and Phe288 of AChE, all of which fall under active site/subsite or binding pocket, might be critical for the inhibitory activity of AChE. This approach might be helpful to understand the selectivity of the given drug molecule in the treatment of Alzheimer's disease. The study provides evidence for consideration of C28H34N2O6 as a valuable small ligand molecule in treatment and prevention of AD associated disorders and further in vitro and in vivo investigations may prove its therapeutic potential.

Novel acetylcholinesterase target site for malaria mosquito control.

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Yuan-Ping Pang

2006-12-01

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.

Novel hybrids of oxoisoaporphine-tryptamine as acetylcholinesterase-induced β-amyloid aggregation inhibitors with improved antioxidant properties

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Zhao Hai-Tao

2015-01-01

Full Text Available A series of dual binding site acetylcholinesterase (AChE inhibitors have been designed, synthesized, and tested for their antioxidant ability and inhibitory potency on AChE and AChE-induced b-amyloid (Ab aggregation. The new hybrids consist of a unit of 1-azabenzanthrone and a tryptamine or its derivative, connected through a a,w - alkyldiamide bridge. These hybrids exhibit moderate AChE inhibitory activity with IC50 values in the micromolar range and significant in vitro inhibitory activity toward the AChE-induced Ab aggregation. Moreover, six out of the nine hybrids of this series exhibit a higher oxygen radical absorbance capacity than trolox, which makes them promising anti-Alzheimer drug candidates.

Facile synthesis of new carbon-11 labeled conformationally restricted rivastigmine analogues as potential PET agents for imaging AChE and BChE enzymes

International Nuclear Information System (INIS)

Wang Min; Wang Jiquan; Gao Mingzhang; Zheng Qihuang

2008-01-01

Rivastigmine is a newer-generation inhibitor with a dual inhibitory action on both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes, and is used for the treatment of AChE- and BChE-related diseases such as brain Alzheimer's disease and cardiovascular disease. New carbon-11 labeled conformationally restricted rivastigmine analogues radiolabeled quaternary ammonium triflate salts, (3aR,9bS)-1-[ 11 C]methyl-1-methyl-6-(methylcarbamoyloxy)-2,3,3a,4,5, 9b-hexahy dro-1H-benzo[g]indolium triflate ([ 11 C]8) and (3aR,9bS)-1-[ 11 C]methyl-1-methyl-6-(heptylcarbamoyloxy)-2,3,3a,4,5, 9b-hexahy dro-1H-benzo[g]indolium triflate ([ 11 C]9), were designed and synthesized as potential positron emission tomography (PET) agents for imaging AChE and BChE enzymes. The appropriate precursors were labeled with [ 11 C]CH 3 OTf through N-[ 11 C]methylation, and the target tracers were isolated by solid-phase extraction (SPE) using a cation-exchange CM Sep-Pak cartridge in 40-50% radiochemical yields decay corrected to end of bombardment (EOB), 15-20 min overall synthesis time, and 148-222 GBq/μmol specific activity at EOB

Hydrogen peroxide modifies both activity and isoforms of acetylcholinesterase in human neuroblastoma SH-SY5Y cells

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Alba Garcimartín

2017-08-01

Full Text Available The involvement of cholinergic system and the reactive oxygen species (ROS in the pathogenesis of some degenerative diseases has been widely reported; however, the specific impact of hydrogen peroxide (H2O2 on the acetylcholinesterase (AChE activity as well as AChE isoform levels has not been clearly established. Hence, the purpose of present study is to clarify whether H2O2 alters these parameters.Human neuroblastoma SH-SY5Y cells were treated with H2O2 (1–1000 µM for 24 h and AChE activity and AChE and cytochrome c levels were evaluated. AChE activity was strongly increased from 1 µM to 1000 µM of H2O2. The results of the kinetic study showed that H2O2 affected Vmax but not Km; and also that H2O2 changed the sigmoid kinetic observed in control samples to hyperbolic kinetic. Thus, results suggest that H2O2 acts as an allosteric activators. In addition, H2O2, (100–1000 µM reduced the total AChE content and modified its isoform profile (mainly 50-, 70-, and 132-kDa·H2O2 from 100 µM to 1000 µM induced cytochrome c release confirming cell death by apoptosis. All these results together suggest: a the involvement of oxidative stress in the imbalance of AChE; and b treatment with antioxidant agents may be a suitable strategy to protect cholinergic system alterations promoted by oxidative stress. Keywords: Acetylcholinesterase, Hydrogen peroxide, Alternative splicing, Cell culture, Cell death

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

Science.gov (United States)

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.

Acetylcholinesterase Inhibitory Activity of Green Tea Polyphenols ...

African Journals Online (AJOL)

Inhibition of acetylcholinesterase activity is one of the most popular approaches for treatment of neurological disorders such as Alzheimer's disease and others. In the present study, we evaluated inhibition of acetylcholinesterase activity by different concentrations of green tea (Camellia sinensis L.) extract using ...

Acetylcholinesterase-independent protective effects of huperzine A against iron overload-induced oxidative damage and aberrant iron metabolism signaling in rat cortical neurons.

Science.gov (United States)

Tao, Ling-Xue; Huang, Xiao-Tian; Chen, Yu-Ting; Tang, Xi-Can; Zhang, Hai-Yan

2016-11-01

Iron dyshomeostasis is one of the primary causes of neuronal death in Alzheimer's disease (AD). Huperzine A (HupA), a natural inhibitor of acetylcholinesterase (AChE), is a licensed anti-AD drug in China and a nutraceutical in the United Sates. Here, we investigated the protective effects of HupA against iron overload-induced injury in neurons. Rat cortical neurons were treated with ferric ammonium citrate (FAC), and cell viability was assessed with MTT assays. Reactive oxygen species (ROS) assays and adenosine triphosphate (ATP) assays were performed to assess mitochondrial function. The labile iron pool (LIP) level, cytosolic-aconitase (c-aconitase) activity and iron uptake protein expression were measured to determine iron metabolism changes. The modified Ellman's method was used to evaluate AChE activity. HupA significantly attenuated the iron overload-induced decrease in neuronal cell viability. This neuroprotective effect of HupA occurred concurrently with a decrease in ROS and an increase in ATP. Moreover, HupA treatment significantly blocked the upregulation of the LIP level and other aberrant iron metabolism changes induced by iron overload. Additionally, another specific AChE inhibitor, donepezil (Don), at a concentration that caused AChE inhibition equivalent to that of HupA negatively, influenced the aberrant changes in ROS, ATP or LIP that were induced by excessive iron. We provide the first demonstration of the protective effects of HupA against iron overload-induced neuronal damage. This beneficial role of HupA may be attributed to its attenuation of oxidative stress and mitochondrial dysfunction and elevation of LIP, and these effects are not associated with its AChE-inhibiting effect.

Comedication and Treatment Length in Users of Acetylcholinesterase Inhibitors

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Anne Sverdrup Efjestad

2017-02-01

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

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

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2013-01-01

reactivated than AChE conjugates inhibited by the corresponding Rp enantiomers and this effect is enhanced as the size of the O-alkyl substituents of OP...Organophosphates and Carbamates, Butterworth & Heinemann , Oxford, 1992. pp. 555–577. [2] P. Taylor, Anticholinesterase agents, in: L.L. Brunton, J.S...application of the Hammett equation with the constants rph in the chemistry of organophosphorus compounds, Russ. Chem. Rev. 38 (1969) 795–811. [13

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

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Xin Wang

2016-03-01

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

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

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Diansan Su

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

Bioassay-Guided Isolated Compounds from Morinda officinalis Inhibit Alzheimer’s Disease Pathologies

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Yoon Kyoung Lee

2017-09-01

Full Text Available Due to the side effects of synthetic drugs, the therapeutic potential of natural products for Alzheimer’s disease (AD has gained interest. Morinda officinalis has demonstrated inhibitory effects on geriatric diseases, such as bone loss and osteoporosis. However, although AD is a geriatric disease, M. officinalis has not been evaluated in an AD bioassay. Therefore, M. officinalis extracts and fractions were tested for AD-related activity, including inhibition of acetylcholinesterase (AChE, butyrylcholinesterase (BChE, β-site amyloid precursor protein cleaving enzyme 1 (BACE1, and advanced glycation end-product (AGE formation. A bioassay-guided approach led to isolation of 10 active compounds, eight anthraquinones (1–8, one coumarin (9, and one phytosterol (10, from n-hexane and ethyl acetate fractions of M. officinalis. The five anthraquinones (4–8 were stronger inhibitors of AChE than were other compounds. Compounds 3 and 9 were good inhibitors of BChE, and compounds 3 and 8 were good inhibitors of BACE1. Compounds 1–5 and 7–9 were more active than the positive control in inhibiting AGE formation. In addition, we first suggested a structure-activity relationship by which anthraquinones inhibit AChE and BACE1. Our findings demonstrate the preventive and therapeutic efficacy of M. officinalis for AD and its potential use as a natural alternative medicine.

Brain regional acetylcholinesterase activity and muscarinic acetylcholine receptors in rats after repeated administration of cholinesterase inhibitors and its withdrawal

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Kobayashi, Haruo; Suzuki, Tadahiko; Sakamoto, Maki; Hashimoto, Wataru; Kashiwada, Keiko; Sato, Itaru; Akahori, Fumiaki; Satoh, Tetsuo

2007-01-01

Activity of acetylcholinesterase (AChE) and specific binding of [ 3 H]quinuclidinyl benzilate (QNB), [ 3 H]pirenzepine (PZP) and [ 3 H]AF-DX 384 to muscarinic acetylcholine receptor (mAChR) preparations in the striatum, hippocampus and cortex of rats were determined 1, 6 and 11 days after the last treatment with an organophosphate DDVP, a carbamate propoxur or a muscarinic agonist oxotremorine as a reference for 7 and 14 days. AChE activity was markedly decreased in the three regions 1 day after the treatment with DDVP for 7 and 14 days with a gradual recovery 6 to 11 days, and much less decreased 1, 6 and 11 days after the treatment with propoxur for 7 days but not for 14 days in the hippocampus and cortex. The binding of [ 3 H]-QNB, PZP and AF-DX 384 in the three regions was generally decreased by the treatment with DDVP for 7 and 14 days. Such down-regulations were generally restored 6 or 11 days after the treatment for 7 but not for 14 days. The down-regulation or up-regulation as measured by [ 3 H]-QNB, PZP and AF-DX 384 was observed 1, 6 or 11 days after treatment with propoxur for 7 days and/or 14 days. Repeated treatment with oxotremorine produced similar effects except AChE activity to DDVP. These results suggest that repeated inhibition of AChE activity may usually cause down-regulation of mAChRs with some exception in the hippocampus when a reversible antiChE propoxur is injected

Kinetics of Huperzine A Dissociation from Acetylcholinesterase via Multiple Unbinding Pathways.

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Rydzewski, Jakub; Jakubowski, Rafal; Nowak, Wieslaw; Grubmüller, Helmut

2018-05-01

The dissociation of huperzine A (hupA) from Torpedo californica acetylcholinesterase (TcAChE) was investigated by 4-microsecond unbiased and biased all-atom molecular dynamics (MD) simulations in explicit solvent. We performed our study using memetic sampling (MS) for the determination of reaction pathways (RPs), metadynamics to calculate free energy, and maximum-likelihood estimation (MLE) to recover kinetic rates from unbiased MD simulations. Our simulations suggest that the dissociation of hupA occurs mainly via two RPs: a front-door along the axis of the active-site gorge (pwf) and through a new transient side-door (pws), i.e., formed by the Omega-loop (residues 67--94 of TcAChE). Analysis of the inhibitor unbinding along the RPs suggests that pws is opened transiently after hupA and the Omega-loop reach a low free-energy transition state characterized by the orientation of the pyridone group of the inhibitor directed toward the Omega-loop plane. Unlike pws, pwf does not require large structural changes of TcAChE to be accessible. The estimated free energies and rates agree well with available experimental data. The dissociation rates along the unbinding pathways are similar, suggesting that the dissociation of hupA along pws is likely to be relevant. This indicates that perturbations to hupA-TcAChE interactions could potentially induce pathway hopping. In summary, out results characterize the slow-onset inhibition of TcAChE by hupA, which may provide the structural and energetic basis for the rational design of the next-generation slow-onset inhibitors with optimized pharmacokinetic properties for the treatment of Alzheimer's disease.

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

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Zhang, Sh.; Li, Sh.; Ma, J.; Xiong, F.; Qu, S.; Zhang, Sh.; Li, Sh.

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 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

Sublethal Effects of Insecticide Exposure on Megacopta cribraria (Fabricius) Nymphs: Key Biological Traits and Acetylcholinesterase Activity.

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Miao, Jin; Reisig, Dominic D; Li, Guoping; Wu, Yuqing

2016-01-01

Megacopta cribraria F. (Hemiptera: Plataspidae), the kudzu bug, is an invasive insect pest of U.S. soybean. At present, insecticide application is the primary and most effective control option for M. cribraria In this study, the potential effects of sublethal and low-lethal concentrations (LC10 and LC40) of three common insecticides on key biological traits and acetylcholinesterase (AChE) activity of the treated nymphal stage of insect were assessed. The results show that the sublethal concentration of imidacloprid significantly reduced adult emergence rate of M. cribraria A low-lethal concentration of imidacloprid significantly increased nymphal development time, but significantly decreased adult emergence rate and adult longevity. Both sublethal and low-lethal concentrations of acephate caused an increase in nymphal development time and a reduction in adult emergence rate and adult longevity. Fecundity of females was significantly reduced only by exposure to low-lethal concentrations of acephate. Sublethal and low-lethal concentrations of bifenthrin increased nymphal development time, but significantly decreased adult emergence rate. In addition, we found that the AChE activity of M. cribraria was significantly increased only by LC40 imidacloprid, but strongly inhibited by acephate. © The Author 2016. Published by Oxford University Press on behalf of the Entomological Society of America.

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

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

2011-01-01

A treatment to the Alzheimer's disease consists inhibition of the acetylcholinesterase, which is responsible for the acetylcholine control in the synapses. 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. Retention factor analysis shows values of 0.31aA, 0.31aA, and 0.46aB for flowers B. variegata, B. var. candida, and B. ungulata, respectively. The flower extract of B. ungulata is the most suitable for further studies on this inhibition.

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

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Sri Devi Sukumaran

2016-07-01

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

Pharmacological characterization of RS-1259, an orally active dual inhibitor of acetylcholinesterase and serotonin transporter, in rodents: possible treatment of Alzheimer's disease.

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

2003-09-01

A dual inhibitor of acetylcholinesterase (AChE) and serotonin transporter (SERT), RS-1259 (4-[1S)-methylamino-3-(4-nitrophenoxy)]propylphenyl N,N-dimethylcarbamate (fumaric acid)(1/2)salt), was newly synthesized. RS-1259 simultaneously inhibited AChE and SERT in the brain following an oral administration in mice and rats. Actual simultaneous elevation of extracellular levels of 5-HT and ACh in the rat hippocampus was confirmed by microdialysis. The compound was as effective as SERT inhibitors such as fluoxetine and fluvoxamine in a 5-hydroxytryptophan-enhancing test in mice. Spatial memory deficits in the two-platform task of a water maze in aged rats were ameliorated by RS-1259 as well as donepezil. Both RS-1259 and donepezil increased the awake episodes in the daytime electroencephalogram of rats. Although RS-1259 was weaker than donepezil in enhancing central cholinergic transmission, as observed by ACh elevation in the hippocampus and memory enhancement in aged rats, the efficacy of RS-1259 on the consciousness level, which reflects the whole activity in the brain, was almost the same as that of donepezil. These results suggest that both cholinergic and serotonergic systems are involved in maintaining brain arousal and that a dual inhibitor of AChE and SERT may be useful for the treatment of cognitive disorders associated with reduced brain activity such as in Alzheimer's disease.

A method for acetylcholinesterase staining of brain sections previously processed for receptor autoradiography.

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Lim, M M; Hammock, E A D; Young, L J

2004-02-01

Receptor autoradiography using selective radiolabeled ligands allows visualization of brain receptor distribution and density on film. The resolution of specific brain regions on the film often can be difficult to discern owing to the general spread of the radioactive label and the lack of neuroanatomical landmarks on film. Receptor binding is a chemically harsh protocol that can render the tissue virtually unstainable by Nissl and other conventional stains used to delineate neuroanatomical boundaries of brain regions. We describe a method for acetylcholinesterase (AChE) staining of slides previously processed for receptor binding. AChE staining is a useful tool for delineating major brain nuclei and tracts. AChE staining on sections that have been processed for receptor autoradiography provides a direct comparison of brain regions for more precise neuroanatomical description. We report a detailed thiocholine protocol that is a modification of the Koelle-Friedenwald method to amplify the AChE signal in brain sections previously processed for autoradiography. We also describe several temporal and experimental factors that can affect the density and clarity of the AChE signal when using this protocol.

An Unusual Dimeric Inhibitor of Acetylcholinesterase: Cooperative Binding of Crystal Violet

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Anders Allgardsson

2017-08-01

Full Text Available Acetylcholinesterase (AChE is an essential enzyme that terminates cholinergic transmission by a rapid hydrolysis of the neurotransmitter acetylcholine. AChE is an important target for treatment of various cholinergic deficiencies, including Alzheimer’s disease and myasthenia gravis. In a previous high throughput screening campaign, we identified the dye crystal violet (CV as an inhibitor of AChE. Herein, we show that CV displays a significant cooperativity for binding to AChE, and the molecular basis for this observation has been investigated by X-ray crystallography. Two monomers of CV bind to residues at the entrance of the active site gorge of the enzyme. Notably, the two CV molecules have extensive intermolecular contacts with each other and with AChE. Computational analyses show that the observed CV dimer is not stable in solution, suggesting the sequential binding of two monomers. Guided by the structural analysis, we designed a set of single site substitutions, and investigated their effect on the binding of CV. Only moderate effects on the binding and the cooperativity were observed, suggesting a robustness in the interaction between CV and AChE. Taken together, we propose that the dimeric cooperative binding is due to a rare combination of chemical and structural properties of both CV and the AChE molecule itself.

Effects of Lead+Selenium Interaction on Acetylcholinesterase Activity in Brain and Accumulation of Metal in Tissues of Oreochromis niloticus (L., 1758

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Gülsemin Şen

2017-06-01

Full Text Available The potential accumulation of lead in different tissues of Oreochromis niloticus and the effects of selenium in AChE inhibition caused by lead in brain were investigated. Juvenile O. niloticus samples were exposed to combination of 1 mg L-1 and 2 mg L-1 lead and 1mg L-1 lead+2mg L-1 selenium and 2mg L-1 lead+4mg L-1 selenium for 1, 7 and 15 days respectively. The accumulation of lead in gill, brain, liver and muscle tissues was analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS as well as brain acetylcholinesterase (AChE, E.C.3.1.1.7 enzyme activity was also analyzed by spectrophotometric method. No mortality was observed during lead exposure in relation to time period and exposed concentrations. Lead accumulation was occurred in all tissues in relation to time. Maximum lead accumulation occurred in brain tissue, followed by the liver, gills and muscle tissues in relation to time period. Selenium caused decrease accumulation of lead in tissues (all selenium mixtures in muscle tissue on the first day, 1mg L-1 Pb+2mg L-1 selenium in gill tissue on the seventh day, in liver tissue on the seventh day except 2mg L-1 Pb+4mg L-1 selenium mixtures at the end of each of all three test periods. Inhibition of AChE activity was caused by the highest concentration and by the short-term effect of lead. Such effect of lead was eliminated by selenium mixture. Lead and selenium mixture were resulted an increase in activity on 15th day at the highest concentration. Selenium led to decrease in the accumulation of lead in the tissues and caused to improvement in the loss of AChE activity.

Maytenus distichophylla and Salacia crassifolia: source of products with potential acetylcholinesterase inhibition

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Fernanda L. Ferreira

Full Text Available ABSTRACT The phytochemical study of the extract leaves from Maytenus distichophylla Mart. and Salacia crassifolia (Mart. ex Schult. G. Don, Celastraceae, resulted in the isolation of 3-oxofriedelane, 3β-hydroxyfriedelane, 3β,24-dihydroxyfriedelane, 3-oxo-28,29-dihydroxyfriedelane, two mixtures of pentacyclic triterpenes (α-amyrin with β-amyrin and 3β-stearyloxy-urs-12-ene with 3β-stearyloxy-olean-12-ene, 3β-palmityloxy-urs-12-ene, the steroid β-sitosterol and its glycosylated derivative β-glucosyl-β-sitosterol, tritriacontanoic acid and the natural polymer gutta percha. The chemical structures of these constituents were established by IR, 1H and 13C NMR spectral data. Crude extracts, the mixtures of triterpenes and the isolated constituents were subjected to in vitro acetylcholinesterase inhibitory evaluation. Acetylcholinesterase inhibitory effect was observed for crude chloroform extract leaves from M. distichophylla (100% and S. crassifolia (97.93 ± 5.63% and for the triterpenes 3β,24-dihydroxyfriedelane (99.05 ± 1.12%, 3-oxo-28,29-dihydroxyfriedelane (90.59 ± 3.76% and 3β-palmityloxy-urs-12-ene (97.93 ± 1.47%. The percent inhibitions induced by these natural products were very similar to those produced by physostigmine (93.94 ± 2.10% a standard acetylcholinesterase inhibitor. Therefore, these results open perspectives for the use of these species as source of compounds with similar physostigmine pharmacological effect.

Antioxidant and anti-acetylcholinesterase activities of extracts from Rapistrum rugosum in Tunisia

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Omri Hichri Amel

2017-07-01

Full Text Available Objective: To investigate the antioxidant potential and anti-acetylcholinesterase activity of Rapistrum rugosum extracts. Methods: The crude, ethyl acetate, butanol and water extracts prepared from flowers, roots, stems and leaves of Rapistrum rugosum were tested at 1 mg/mL to determine their total polyphenol content, total flavonoid content and total condensed tannin content. Their antioxidant activity was assessed at different concentrations (0.0312, 0.0625, 0.1250, 0.25, 0.50 and 1.00 mg/ mL by using DPPH, ABTS, reducing power and β-carotene bleAChIng inhibition activity. Antiacetylcholinesterase activity was also determined. Results: The extract of leaves and stems had the highest total phenolic content [(110.45依0.03 mg gallic acid equivalent/g dry weight]. The ethyl acetate extract of flowers had the highest total flavonoid content [(24.62依0.13 mg quercetin equivalent/g dry weight]. The butanolic fraction of flowers had the highest total condensed tannin content [(317.85依0.01 mg catechin equivalent/g dry weight]. The crude extracts of flowers exhibited an interesting antioxidant activity for DPPH assay (93.00依0.01% at 1 mg/mL. The greatest acetylcholinesterase inhibitory activity (IC50=1.60 mg/mL was exhibited by the crude extracts from the flowers. Conclusions: The results demonstrated that Rapistrum rugosum contains active constituents which possess antioxidant and anti-acetylcholinesterase activities.

Acotiamide hydrochloride (Z-338), a new selective acetylcholinesterase inhibitor, enhances gastric motility without prolonging QT interval in dogs: comparison with cisapride, itopride, and mosapride.

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Matsunaga, Yugo; Tanaka, Takao; Yoshinaga, Koji; Ueki, Shigeru; Hori, Yuko; Eta, Runa; Kawabata, Yoshihiro; Yoshii, Kazuyoshi; Yoshida, Kenji; Matsumura, Toshihiro; Furuta, Shigeru; Takei, Mineo; Tack, Jan; Itoh, Zen

2011-03-01

Acotiamide hydrochloride (acotiamide; N-[2-[bis(1-methylethyl) amino]ethyl]-2-[(2-hydroxy-4,5-dimethoxybenzoyl) amino] thiazole-4-carboxamide monohydrochloride trihydrate, Z-338) has been reported to improve meal-related symptoms of functional dyspepsia in clinical studies. Here, we examined the gastroprokinetic effects of acotiamide and its antiacetylcholinesterase activity as a possible mechanism of action in conscious dogs. Acotiamide increased postprandial gastric motor activity in conscious dogs with chronically implanted force transducers and, like itopride, mosapride, and cisapride, exhibited gastroprokinetic activity in these dogs. Furthermore, acotiamide improved clonidine-induced hypomotility and delayed gastric emptying. Acotiamide-enhanced postprandial gastroduodenal motility was suppressed completely by pretreatment with atropine, a muscarinic receptor antagonist. In in vitro studies, acotiamide enhanced acetylcholine- but not carbachol-induced contractile responses of guinea pig gastric antrum strips. Moreover, like itopride and neostigmine, acotiamide inhibited recombinant human and canine stomach-derived acetylcholinesterase (AChE) activity in vitro. The mode of the AChE inhibitory action of acotiamide was selective and reversible. Unlike itopride or mosapride, acotiamide showed no affinity for dopamine D(2) or serotonin 5-HT(4) receptors. With regard to cardiovascular side effects, unlike cisapride, acotiamide did not affect myocardial monophasic action potential duration, QT interval, or corrected QT interval in anesthetized dogs. These results suggest that acotiamide stimulates gastric motility in vivo by inhibiting AChE activity without affecting QT interval. Acotiamide thus represents a beneficial new drug for the treatment of functional dyspepsia involving gastric motility dysfunction, with differences from other prokinetic agents.

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

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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)

Effect of high fat diets on the NTPDase, 5'-nucleotidase and acetylcholinesterase activities in the central nervous system.

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Kaizer, Rosilene Rodrigues; Spanevello, Rosélia Maria; Costa, Eduarda; Morsch, Vera Maria; Schetinger, Maria Rosa Chitolina

2018-02-01

High fat diets are associated with the promotion of neurological diseases, such as Alzheimer disease (AD). This study aim investigate the high fat diets role to promotion of AD using as biochemistry parameter of status of central nervous system through the NTPDase, 5'-nucleotidase and acetylcholinesterase (AChE) activities in brain of young rats. The intake of high fat diets promotes an inhibition of purinergic and cholinergic functions, mainly in the long-term exposure to saturated and saturated/unsaturated diets. The AChE activity was decreased to supernatant and synaptosomes tissues preparations obtained from cerebral cortex in average of 20%, to both groups exposed to saturated and saturated/unsaturated diets, when compared to the control group. Very similar results were found in hippocampus and cerebellum brain areas. At same time, the adenine nucleotides hydrolysis in synaptosomes of cerebral cortex were decreased to ATP, ADP and AMP after the long-term exposure to high fat diets, as saturated and saturated/unsaturated. The inhibition of ATP hydrolysis was of 26% and 39% to saturated and saturated/unsaturated diets, respectively. ADP hydrolysis was decreased in 20% to saturated diet, and AMP hydrolysis was decreased in 25% and 33% to saturated and saturated/unsaturated diets, respectively, all in comparison to the control. Thus, we can suggest that the effects of high diets on the purinergic and cholinergic nervous system may contribute to accelerate the progressive memory loss, to decline in language and other cognitive disruptions, such as AD patients presents. Copyright © 2017 ISDN. Published by Elsevier Ltd. All rights reserved.

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

International Nuclear Information System (INIS)

Haas, R.; Marshall, T.L.; Rosenberry, T.L.

1988-01-01

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-[ 125 I]iodophenyl)diazirine ([ 125 I]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

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

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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.

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

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Sofia Benfeito

2014-01-01

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

Natural monomeric form of fetal bovine serum acetylcholinesterase lacks the C-terminal tetramerization domain.

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Saxena, Ashima; Hur, Regina S; Luo, Chunyuan; Doctor, Bhupendra P

2003-12-30

Acetylcholinesterase isolated from fetal bovine serum (FBS AChE) was previously characterized as a globular tetrameric form. Analysis of purified preparations of FBS AChE by gel permeation chromatography revealed the presence of a stable, catalytically active, monomeric form of this enzyme. The two forms could be distinguished from each other based on their molecular weight, hydrodynamic properties, kinetic properties, thermal stability, and the type of glycans they carry. No differences between the two forms were observed for the binding of classical inhibitors such as edrophonium and propidium or inhibitors that are current or potential drugs for the treatment of Alzheimer's disease such as (-) huperzine A and E2020; tacrine inhibited the monomeric form 2-3-fold more potently than the tetrameric form. Sequencing of peptides obtained from an in-gel tryptic digest of the monomer and tetramer by tandem mass spectrometry indicated that the tetramer consists of 583 amino acid residues corresponding to the mature form of the enzyme, whereas the monomer consists of 543-547 amino acid residues. The subunit molecular weight of the protein component of the monomer (major species) was determined to be 59 414 Da and that of the tetramer as 64 239 Da. The N-terminal of the monomer and the tetramer was Glu, suggesting that the monomer is not a result of truncation at the N-terminal. The only differences detected were at the C-terminus. The tetramer yielded the expected C-terminus, CSDL, whereas the C-terminus of the monomer yielded a mixture of peptides, of which LLSATDTLD was the most abundant. These results suggest that monomeric FBS AChE is trimmed at the C-terminus, and the results are consistent with the involvement of C-terminal amino acids in the assembly of monomers into tetramers.

In vitro toxicity, antiplatelet and acetylcholinesterase inhibition of Buddleja thyrsoides Lam. leaves.

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Mahlke, Janaína Dorneles; Boligon, Aline Augusti; Machado, Michel Mansur; Athayde, Margareth Linde

2012-01-01

Alzheimer's disease (AD) is a neurodegenerative disorder resulting in impaired memory and behaviour of remarkable socio-economic impact. A decrease in cholinergic activity is a key event in the biochemical of AD. Buddleja thyrsoides is a plant widely distributed in Southern parts of South America. In Brazilian traditional medicine, the infusion of its leaves and flowers is used for the treatment of bronchitis and cough. Crude ethanolic (70%) extract and fractions (dichloromethane, ethyl acetate and n-butanolic) were investigated regarding their toxicities in vitro and antiplatelet action. The enzyme acetylcholinesterase inhibition was evaluated to study the crude extract. The crude extract and fractions were evaluated by means of Brine Shrimp Lethality test and they showed low activities with LC(50) values 1698, 2818, 2187 and 3672 µg mL(-1) for dichloromethane, ethyl acetate, n-butanolic fractions and crude extract, respectively. Buddleja thyrsoides presented great antiplatelet action. The IC(50) values obtained for crude extract and dichloromethane, ethyl acetate and n-butanolic fractions were 361.29, 354.23, 368.75 and 344.30, respectively, while the IC(50) for the standard AAS was 257.01 µg mL(-1). The crude extract showed an inhibition of 22.8% of the acetylcholinesterase enzyme in 24 h.

Structural characterization of acetylcholinesterase 1 from the sand fly Lutzomyia longipalpis (Diptera: Psychodidae).

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Coutinho-Abreu, I V; Balbino, V Q; Valenzuela, J G; Sonoda, I V; Ramalho-Ortigão, J M

2007-07-01

Acetylcholinesterase (AChE) plays a key role in cholinergic impulse transmission, and it is the target enzyme for organophosphorus and carbamate insecticides. Two genes, AceI and AceII, have been characterized from different insect species, and point mutations in either gene can lead to significant resistance to these classes of insecticides. In this report, we describe the partial characterization of the AceI gene from Lutzomyia longipalpis (Lutz & Neiva) (Diptera: Psychodidae), and we show that the possibility exists for the development of a resistant phenotype to organophosphates and carbamates in sand flies. Our results point to the presence of a single AceI gene in L. longipalpis (LlAce1) and that AChE activity is inhibited by organophosphorus at a concentration of 5 x 10(-5) M. Regarding insecticide resistance, analysis of the truncated LlAce1 cDNA suggests that a single missense mutation leading to a glycine-to-serine substitution at amino acid position 119 (G119S) may arise in L. longipalpis, similar to what has been detected in Anopheles gambiae s.s. Another missense mutation involved in resistant phenotypes, F331W, detected in Culex tritaeniorhynchus Giles, is less likely to occur in L. longipalpis, because it faces codon constraint in this sand fly species. Comparison of the three-dimensional structures of the deduced amino acid sequence of the truncated LLAChE1 with that of An. gambiae and Cx. tritaeniorhynchus also suggests that similar structural modifications due to the missense amino acid changes in the active site gorge are detected in all three insects.

The non-competitive acetylcholinesterase inhibitor APS12-2 is a potent antagonist of skeletal muscle nicotinic acetylcholine receptors

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Grandič, Marjana; Aráoz, Romulo; Molgó, Jordi; Turk, Tom; Sepčić, Kristina; Benoit, Evelyne; Frangež, Robert

2012-01-01

APS12-2, a non-competitive acetylcholinesterase inhibitor, is one of the synthetic analogs of polymeric alkylpyridinium salts (poly-APS) isolated from the marine sponge Reniera sarai. In the present work the effects of APS12-2 were studied on isolated mouse phrenic nerve–hemidiaphragm muscle preparations, using twitch tension measurements and electrophysiological recordings. APS12-2 in a concentration-dependent manner blocked nerve-evoked isometric muscle contraction (IC 50 = 0.74 μM), without affecting directly-elicited twitch tension up to 2.72 μM. The compound (0.007–3.40 μM) decreased the amplitude of miniature endplate potentials until a complete block by concentrations higher than 0.68 μM, without affecting their frequency. Full size endplate potentials, recorded after blocking voltage-gated muscle sodium channels, were inhibited by APS12-2 in a concentration-dependent manner (IC 50 = 0.36 μM) without significant change in the resting membrane potential of the muscle fibers up to 3.40 μM. The compound also blocked acetylcholine-evoked inward currents in Xenopus oocytes in which Torpedo (α1 2 β1γδ) muscle-type nicotinic acetylcholine receptors (nAChRs) have been incorporated (IC 50 = 0.0005 μM), indicating a higher affinity of the compound for Torpedo (α1 2 β1γδ) than for the mouse (α1 2 β1γε) nAChR. Our data show for the first time that APS12-2 blocks neuromuscular transmission by a non-depolarizing mechanism through an action on postsynaptic nAChRs of the skeletal neuromuscular junction. -- Highlights: ► APS12-2 produces concentration-dependent inhibition of nerve-evoked muscle contraction in vitro. ► APS12-2 blocks MEPPs and EPPs at the neuromuscular junction. APS12-2 blocks ACh-activated current in Xenopus oocytes incorporated with Torpedo nAChRs.

Synthesis and discovery of potent carbonic anhydrase, acetylcholinesterase, butyrylcholinesterase, and α-glycosidase enzymes inhibitors: The novel N,N'-bis-cyanomethylamine and alkoxymethylamine derivatives.

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Taslimi, Parham; Caglayan, Cuneyt; Farzaliyev, Vagif; Nabiyev, Oruj; Sujayev, Afsun; Turkan, Fikret; Kaya, Ruya; Gulçin, İlhami

2018-04-01

During this investigation, N,N'-bis-azidomethylamines, N,N'-bis-cyanomethylamine, new alkoxymethylamine and chiral derivatives, which are considered to be a new generation of multifunctional compounds, were synthesized, functional properties were investigated, and anticholinergic and antidiabetic properties of those compounds were studied through the laboratory tests, and it was approved that they contain physiologically active compounds rather than analogues. Novel N-bis-cyanomethylamine and alkoxymethylamine derivatives were effective inhibitors of the α-glycosidase, cytosolic carbonic anhydrase I and II isoforms, butyrylcholinesterase (BChE), and acetylcholinesterase (AChE) with K i values in the range of 0.15-13.31 nM for α-glycosidase, 2.77-15.30 nM for human carbonic anhydrase isoenzymes I (hCA I), 3.12-21.90 nM for human carbonic anhydrase isoenzymes II (hCA II), 23.33-73.23 nM for AChE, and 3.84-48.41 nM for BChE, respectively. Indeed, the inhibition of these metabolic enzymes has been considered as a promising factor for pharmacologic intervention in a diversity of disturbances. © 2018 Wiley Periodicals, Inc.

Changes in antioxidant status, protein concentration, acetylcholinesterase, (Na+,K+)-, and Mg2+ -ATPase activities in the brain of hyper- and hypothyroid adult rats.

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Carageorgiou, Haris; Pantos, Constantinos; Zarros, Apostolos; Mourouzis, Iordanis; Varonos, Dennis; Cokkinos, Dennis; Tsakiris, Stylianos

2005-06-01

It is a common knowledge that metabolic reactions increase in hyperthyroidism and decrease in hypothyroidism. The aim of this work was to investigate how the metabolic reactions could affect the total antioxidant status (TAS), protein concentration (PC) and the activities of acetylcholinesterase (AChE), (Na+,K+)-ATPase and Mg2+ -ATPase in the brain of hyper- and hypothyroid adult male rats. Hyperthyroidism was induced in rats by subcutaneous administration of thyroxine (25 microg/l00 g body weight) once daily for 14 days, while hypothyroidism was induced by oral administration of propylthiouracil (0.05%) for 21 days. TAS, PC, and enzyme activities were evaluated spectrophotometrically in the homogenated brain of each animal. TAS, PC, and Mg2+ -ATPase activity were found unaffected in hyperthyroidism, while AChE and Na+,K+ -ATPase activities were reduced by 25% (p activities were found to be increased (approx. 23-30%, p activity and PC were shown to be inhibited (approx. 23-30%, p activities may reflect the different metabolic effects of hyper- and hypothyroidism. Such changes of the enzyme activities may differentially modulate the brain intracellular Mg2+, neural excitability, as well as the uptake and release of biogenic amines.

Acetylcholinesterase and Butyrylcholinesterase Inhibited by Paraoxon

Czech Academy of Sciences Publication Activity Database

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 - others:MO0(CZ) FZV0000604 Institutional research plan: CEZ:AV0Z40720504 Keywords : acetylcholinesterase * reactivator * oxime Subject RIV: CC - Organic Chemistry Impact factor: 1.738, year: 2009

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

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Watabe, Tadashi; Naka, Sadahiro; Ikeda, Hayato; Horitsugi, Genki; Kanai, Yasukazu; Isohashi, Kayako; Ishibashi, Mana; Kato, Hiroki; Shimosegawa, Eku; Watabe, Hiroshi; Hatazawa, Jun

2014-01-01

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

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

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Tadashi Watabe

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

Synthesis of Novel Chalcones as Acetylcholinesterase Inhibitors

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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.

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

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Ballesteros, M.L.; Durando, P.E.; Nores, M.L.; Diaz, M.P.; Bistoni, M.A.; Wunderlin, D.A.

2009-01-01

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.

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

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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.

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

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

1988-06-01

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

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

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

2016-01-01

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

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

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Gotkine Marc

2013-01-01

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

Synthesis, docking and acetylcholinesterase inhibitory assessment of 2-(2-(4-Benzylpiperazin-1-yl)ethyl)isoindoline-1,3-dione derivatives with potential anti-Alzheimer effects

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2013-01-01

Background Alzheimer’s disease (AD) as neurodegenerative disorder, is the most common form of dementia accounting for about 50-60% of the overall cases of dementia among persons over 65 years of age. Low acetylcholine (ACh) concentration in hippocampus and cortex areas of the brain is one of the main reasons for this disease. In recent years, acetylcholinesterase (AChE) inhibitors like donepezil with prevention of acetylcholine hydrolysis can enhance the duration of action of acetylcholine in synaptic cleft and improve the dementia associated with Alzheimer’s disease. Results Design, synthesis and assessment of anticholinesterase activity of 2-(2-(4-Benzylpiperazin-1-yl)ethyl)isoindoline-1,3-dione derivatives showed prepared compounds can function as potential acetylcholinesterase inhibitor. Among 12 synthesized derivatives, compound 4a with ortho chlorine moiety as electron withdrawing group exhibited the highest potency in these series (IC50 = 0.91 ± 0.045 μM) compared to donepezil (IC50 = 0.14 ± 0.03 μM). The results of the enzyme inhibition test (Ellman test) showed that electron withdrawing groups like Cl, F and NO2 can render the best effect at position ortho and para of the phenyl ring. But compound 4g with methoxy group at position 3(meta) afforded a favorable potency (IC50 = 5.5 ± 0.7 μM). Furthermore, docking study confirmed a same binding mode like donepezil for compound 4a. Conclusions Synthesized compounds 4a-4l could be proposed as potential anticholinesterase agents. PMID:23758724

Synthesis, Docking and Acetylcholinesterase Inhibitory Assessment of 2-(2-(4-Benzylpiperazin-1-YlEthylIsoindoline-1,3-Dione Derivatives with Potential Anti-Alzheimer Effects

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Ahmad Mohammadi-Farani

2013-06-01

Full Text Available Background:Alzheimer’s disease (AD as neurodegenerative disorder, is the most common form of dementia accounting for about 50-60% of the overall cases of dementia among persons over 65 years of age. Low acetylcholine (ACh concentration in hippocampus and cortex areas of the brain is one of the main reasons for this disease. In recent years, acetylcholinesterase (AChE inhibitors like donepezil with prevention of acetylcholine hydrolysis can enhance the duration of action of acetylcholine in synaptic cleft and improve the dementia associated with Alzheimer’s disease.Results:Design, synthesis and assessment of anticholinesterase activity of 2-(2-(4-Benzylpiperazin-1-ylethylisoindoline-1,3-dione derivatives showed prepared compounds can function as potential acetylcholinesterase inhibitor. Among 12 synthesized derivatives, compound 4a with ortho chlorine moiety as electron withdrawing group exhibited the highest potency in these series (IC50 = 0.91 ± 0.045 μM compared to donepezil (IC50 = 0.14 ± 0.03 μM. The results of the enzyme inhibition test (Ellman test showed that electron withdrawing groups like Cl, F and NO2 can render the best effect at position ortho and para of the phenyl ring. But compound 4g with methoxy group at position 3(meta afforded a favorable potency (IC50 = 5.5 ± 0.7 μM. Furthermore, docking study confirmed a same binding mode like donepezil for compound 4a.Conclusions:Synthesized compounds 4a-4l could be proposed as potential anticholinesterase agents.

Diethyl 2-(Phenylcarbamoylphenyl Phosphorothioates: Synthesis, Antimycobacterial Activity and Cholinesterase Inhibition

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Jarmila Vinšová

2014-05-01

Full Text Available A new series of 27 diethyl 2-(phenylcarbamoylphenyl phosphorothioates (thiophosphates was synthesized, characterized by NMR, IR and CHN analyses and evaluated against Mycobacterium tuberculosis H37Rv, Mycobacterium avium and two strains of Mycobacterium kansasii. The best activity against M. tuberculosis was found for O-{4-bromo-2-[(3,4-dichlorophenylcarbamoyl]phenyl} O,O-diethyl phosphorothioate (minimum inhibitory concentration of 4 µM. The highest activity against nontuberculous mycobacteria was exhibited by O-(5-chloro-2-{[4-(trifluoromethylphenyl]carbamoyl}-phenyl O,O-diethyl phosphorothioate with MIC values from 16 µM. Prepared thiophosphates were also evaluated against acetylcholinesterase from electric eel and butyrylcholinesterase from equine serum. Their inhibitory activity was compared to that of the known cholinesterases inhibitors galanthamine and rivastigmine. All tested compounds showed a higher (for AChE inhibition and comparable (for BChE inhibition activity to that of rivastigmine, with IC50s within the 8.04 to 20.2 µM range.

Identification of two acetylcholinesterases in Pardosa pseudoannulata and the sensitivity to insecticides.

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Zhang, Yixi; Shao, Ying; Jiang, Feng; Li, Jian; Liu, Zewen

2014-03-01

Pardosa pseudoannulata is an important predatory enemy against insect pests, such as rice planthoppers and leafhoppers. In order to understand the insecticide selectivity between P. pseudoannulata and insect pests, two acetylcholinesterase genes, Pp-ace1 and Pp-ace2, were cloned from this natural enemy. The putative proteins encoded by Pp-ace1 and Pp-ace2 showed high similarities to insect AChE1 (63% to Liposcelis entomophila AChE1) and AChE2 (36% to Culex quinquefasciatus AChE2) with specific functional motifs, which indicated that two genes might encode AChE1 and AChE2 proteins respectively. The recombinant proteins by expressing Pp-ace1 and Pp-ace2 genes in insect sf9 cells showed high AChE activities. The kinetic parameters, Vmax and Km, of two recombinant AChE proteins were significantly different. The sensitivities to six insecticides were determined in two recombinant AChEs. Pp-AChE1 was more sensitive to all tested insecticides than Pp-AChE2, such as fenobucarb (54 times in Ki ratios), isoprocarb (31 times), carbaryl (13 times) and omethoate (6 times). These results indicated that Pp-AChE1 might be the major synaptic enzyme in the spider. By sequence comparison of P. pseudoannulata and insect AChEs, the key amino acid differences at or close to the functional sites were found. The locations of some key amino acid differences were consistent with the point mutation sites in insect AChEs that were associated with insecticide resistance, such as Phe331 in Pp-AChE2 corresponding to Ser331Phe mutation in Myzus persicae and Aphis gossypii AChE2, which might play important roles in insecticide selectivity between P. pseudoannulata and insect pests. Of course, the direct evidences are needed through further studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

The reactivation effect of pralidoxime in human blood on parathion and paraoxon–induced cholinesterase inhibition

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Mahvash Jafari

2006-03-01

Full Text Available In this investigation the reactivation of cholinesterases by pralidoxime in parathion and paraoxon intoxication in plasma and erythrocytes were studied. For this purpose, human plasma and erythrocytes were incubated with various concentrations of parathion (0.1-10 µM and paraoxon (0.03-0.3 µM at 37 oC for 10 min. Then, pralidoxime (10-300 µM was added to the samples and incubated for 10 min before cholinesterases assay. The results showed that effects of parathion and paraoxon were dose dependent. These agents inhibited more than 85% of butyrylcholinesterase (BChE and acetylcholinesterase (AChE activity and the inhibitory effect of paraoxon was 10 times more than parathion. BChE activity was significantly higher than the control at 100 µM of pralidoxime and it reduced inhibitory effects of parathion to less than 50% and of paraoxon to 42% of control. When pralidoxime (10 µM was added to erythrocytes, the inhibitory effects of two organophosphates were reduced to less than 15%. At higher concentrations of pralidoxime (>100 µM, both BChE and AChE activities were inhibited.

Is subnanomolar binding affinity required for the in vivo imaging of acetylcholinesterase? Studies on 18F-labeled G379

International Nuclear Information System (INIS)

Lee, Sang-Yoon; Choe, Yearn Seong; Ryu, Eun Kyoung; Iimura, Yoichi; Choi, Yong; Lee, Kyung-Han; Kim, Byung-Tae

2006-01-01

Acetylcholinesterase (AChE) is an important cholinergic marker of Alzheimer's disease (AD) and shows reduced activity in postmortem AD brain tissues. 1-(4-Fluorobenzyl)-4-[(5,6-dimethoxy-1-oxoindan-2-fluoro-2-yl)methyl] piperidine (G379, ), an AChE inhibitor with a subnanomolar IC 5 (0.56 nM), was prepared as a 18 F-labeled radioligand ([ 18 F]) and evaluated in mice. Metabolism studies of [ 18 F] showed no metabolites in the mouse brain. Tissue distribution studies demonstrated its uniform regional distribution in the mouse brain, suggesting that this radioligand is not suitable for the in vivo imaging of AChE. This result along with reports on radiolabeled N-benzylpiperidine lactam benzisoxazole (IC 5 5 >1 nM) suggested that a subnanomolar IC 5 may not be the only important factor in determining the suitability of a radioligand for in vivo studies of AChE

Amino acid substitutions and intron polymorphism of acetylcholinesterase1 associated with mevinphos resistance in diamondback moth, Plutella xylostella (L.).

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Yeh, Shih-Chia; Lin, Chia-Li; Chang, Cheng; Feng, Hai-Tung; Dai, Shu-Mei

2014-06-01

The diamondback moth, Plutella xylostella L., is the most destructive insect pest of Brassica crops in the world. It has developed resistance rapidly to almost every insecticide used for its control. Mevinphos, a fast degrading and slow resistance evocating organophosphorus insecticide, has been recommended for controlling P. xylostella in Taiwan for more than 40years. SHM strain of P. xylostella, with ca. 22-fold resistance to this chemical, has been established from a field SH strain by selecting with mevinphos since 1997. Three mutations, i.e., G892T, G971C, and T1156T/G leading to A298S, G324A, and F386F/V amino acid substitutions in acetylcholinesterase1 (AChE1), were identified in these two strains; along with three haplotype pairs and a polymorphic intron in AChE1 gene (ace1). Two genetically pure lines, i.e., an SHggt wild type with intron AS and an SHMTCN mutant carrying G892T, G971C, T1156T/G mutations and intron AR in ace1, were established by single pair mating and haplotype determination. The F1 of SHMTCN strain had 52-fold resistance to mevinphos in comparison with the F1 of SHggt strain. In addition, AChE1 of this SHMTCN population, which exhibited lower maximum velocity (Vmax) and affinity (Km), was less susceptible to the inhibition of mevinphos, with an I50 32-fold higher than that of the SHggt F1 population. These results imply that amino acid substitutions in AChE1 of SHMTCN strain are associated with mevinphos resistance in this insect pest, and this finding is important for insecticide resistance management of P. xylostella in the field. Copyright © 2014 Elsevier Inc. All rights reserved.

Design, synthesis, biological evaluation and docking study of 5-oxo-4,5-dihydropyrano[3,2-c]chromene derivatives as acetylcholinesterase and butyrylcholinesterase inhibitors.

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Khoobi, Mehdi; Alipour, Masoumeh; Sakhteman, Amirhossein; Nadri, Hamid; Moradi, Alireza; Ghandi, Mehdi; Emami, Saeed; Foroumadi, Alireza; Shafiee, Abbas

2013-10-01

A series of fused coumarins namely 5-oxo-4,5-dihydropyrano[3,2-c]chromenes linked to N-benzylpyridinium scaffold were synthesized and evaluated as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitors. The 1-(4-fluorobenzyl)pyridinium derivative 6g showed the most potent anti-AChE activity (IC50 value=0.038 μM) and the highest AChE/BuChE selectivity (SI>48). The docking study permitted us to rationalize the observed structure-affinity relationships and to detect possible binding modes. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Acetylcholinesterase complexed with bivalent ligands related to huperzine a: experimental evidence for species-dependent protein-ligand complementarity.

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Wong, Dawn M; Greenblatt, Harry M; Dvir, Hay; Carlier, Paul R; Han, Yi-Fan; Pang, Yuan-Ping; Silman, Israel; Sussman, Joel L

2003-01-15

Acetylcholinesterase (AChE) inhibitors improve the cognitive abilities of Alzheimer patients. (-)-Huperzine A [(-)-HupA], an alkaloid isolated from the club moss, Huperzia serrata, is one such inhibitor, but the search for more potent and selective drugs continues. Recently, alkylene-linked dimers of 5-amino-5,6,7,8-tetrahydroquinolinone (hupyridone, 1a), a fragment of HupA, were shown to serve as more potent inhibitors of AChE than (-)-HupA and monomeric 1a. We soaked two such dimers, (S,S)-(-)-bis(10)-hupyridone [(S,S)-(-)-2a] and (S,S)-(-)-bis(12)-hupyridone [(S,S)-(-)-2b] containing, respectively, 10 and 12 methylenes in the spacer, into trigonal TcAChE crystals, and solved the X-ray structures of the resulting complexes using the difference Fourier technique, both to 2.15 A resolution. The structures revealed one HupA-like 1a unit bound to the "anionic" subsite of the active-site, near the bottom of the active-site gorge, adjacent to Trp84, as seen for the TcAChE/(-)-HupA complex, and the second 1a unit near Trp279 in the "peripheral" anionic site at the top of the gorge, both bivalent molecules thus spanning the active-site gorge. The results confirm that the increased affinity of the dimeric HupA analogues for AChE is conferred by binding to the two "anionic" sites of the enzyme. Inhibition data show that (-)-2a binds to TcAChE approximately 6-7- and > 170-fold more tightly than (-)-2b and (-)-HupA, respectively. In contrast, previous data for rat AChE show that (-)-2b binds approximately 3- and approximately 2-fold more tightly than (-)-2a and (-)-HupA, respectively. Structural comparison of TcAChE with rat AChE, as represented by the closely related mouse AChE structure (1maa.pdb), reveals a narrower gorge for rat AChE, a perpendicular alignment of the Tyr337 ring to the gorge axis, and its conformational rigidity, as a result of hydrogen bonding between its hydroxyl group and that of Tyr341, relative to TcAChE Phe330. These structural differences in the

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

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

2016-05-04

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.

Evaluation of enzymes inhibition activities of medicinal plant from Burkina Faso.

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Bangou, Mindiédiba Jean; Kiendrebeogo, Martin; Meda, Nâg-Tiero Roland; Coulibaly, Ahmed Yacouba; Compaoré, Moussa; Zeba, Boukaré; Millogo-Rasolodimby, Jeanne; Nacoulma, Odile Germaine

2011-01-15

The aim of the present study was to evaluate some enzymes inhibitory effects of 11 plant species belonging to 9 families from Burkina Faso. Methanolic extracts were used for their Glutathione-s-transferase (GST), Acetylcholinesterase (AChE), Carboxylesterase (CES) and Xanthine Oxidase (XO) inhibitory activities at final concentration of 100 microg mL(-1). The total phenolics, flavonoids and tannins were also determined spectrophotometrically using Folin-Ciocalteu, AlCl3 and ammonium citrate iron reagents, respectively. Among the 11 species tested, the best inhibitory percentages were found with Euphorbia hirta, Sclerocarya birrea and Scoparia dulcis (inhibition > 40%) followed by Annona senegalensis, Annona squamosa, Polygala arenaria and Ceratotheca sesamoides (inhibition > 25%). The best total phenolic and tannin contents were found with S. birrea with 56.10 mg GAE/100 mg extract and 47.75 mg TAE/100 mg extract, respectively. E hirta presented the higher total flavonoids (9.96 mg QE/100 mg extract). It's was found that Sclerocarya birrea has inhibited all enzymes at more than 30% and this activity is correlated to total tannins contents. Contrary to S. birrea, the enzymatic activities of E. hirta and S. dulcis are correlated to total flavonoids contents. Present findings suggest that the methanolic extracts of those plant species are potential inhibitors of GST, AChE, CES and XO and confirm their traditional uses in the treatment of mental disorders, gout, painful inflammations and cardiovascular diseases.

In-vitro screening of acetylcholinesterase inhibitory activity of extracts from Palestinian indigenous flora in relation to the treatment of Alzheimer’s disease

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Mohammed Saleem Ali-Shtayeh

2014-09-01

Full Text Available Background: Cholinesterase inhibitory therapy serves as a strategy for the treatment of Alzheimer’s disease (AD. Several acetylcholinesterase inhibitors (AChEIs are used for the symptomatic treatment of AD. These compounds have been reported to have adverse effects, including gastrointestinal disturbances. This study was therefore partly aimed at investigating in vitro possible AChEIs in herbal medicines traditionally used in Palestine to treat cognitive disorders, and to point out the role of these plants as potential sources for development of newly potent and safe natural therapeutic agents of AD. Assay of AChE activity plays an important role in vitro characterization of drugs including potential treatments for AD. The most widely used method, is based on Ellman’s method. The reactant used in this method shows chemical reactivity with oxime antidots and thiol leading to false positive reactions. A new alternative assay could be of high interest. Methods: The effect on AChE activity of 92 extracts of 47 medicinal plants were evaluated using a new micro-well plate AChE activity (NA-FB and Ellman’s assays. In addition, antioxidant activity using DPPH was determined. Results: The main advantages of the new method (NA-FB is that the colorimetric change is better observable visually allowing spectrophotometric as well as colorimetric assay, and does not show any chemical reactivity with thiol. 67.4% and 37% of extracts inhibited AChE by >50% using the NA-FB and Ellman’s assays, respectively. Using NA-FB assay, 84 extracts interacted reversibly with the enzyme, of which Mentha spicata (94.8%, Foeniculum vulgare (89.81, and Oxalis pes-caprae (89.21 were most potent, and 8 showed irreversible inhibition of which leaves of Lupinus pilosus (92.02% were most active. Antioxidant activity was demonstrated by 73 extracts Majorana syriaca (IC50 0.21mg/ml, and Rosmarinus officinalis (0.38 were the most active. Conclusions: NA-FB assay has shown to be

Improving the acetylcholinesterase inhibitory effect of Illigera henryi by solid-state fermentation with Clonostachys rogersoniana.

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Li, Xue-Jiao; Dong, Jian-Wei; Cai, Le; Mei, Rui-Feng; Ding, Zhong-Tao

2017-11-01

Illigera henryi, an endemic traditional Chinese medicine, contains abundant aporphine alkaloids that possess various bioactivities. In the present study, tubers of I. henryi were fermented by several fungi, and the acetylcholinesterase (AChE) inhibitory activities of non-fermented and fermented I. henryi were measured. The results showed that the fermentation of I. henryi with Clonostachys rogersoniana 828H2 is effective for improving the AChE inhibitory activity. A key biotransformation was found during the C. rogersoniana fermentation for clarifying the improvement of the AChE inhibitory activity of I. henryi: (S)-actinodaphnine (1) was converted to a new 4-hydroxyaporphine alkaloid (4R,6aS)-4-hydroxyactinodaphnine (2) that possessed a stronger AChE inhibitory activity, with an IC 50 value of 17.66±0.06 μM. This paper is the first to report that the pure strain fermentation processing of I. henryi and indicated C. rogersoniana fermentation might be a potential processing method for I. henryi. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Synthesis and DPPH scavenging assay of reserpine analogues, computational studies and in silico docking studies in AChE and BChE responsible for Alzheimer's disease

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Muhammad Yar

2015-03-01

Full Text Available Alzheimer's disease (AD is a fast growing neurodegenerative disorder of the central nervous system and anti-oxidants can be used to help suppress the oxidative stress caused by the free radicals that are responsible for AD. A series of selected synthetic indole derivatives were biologically evaluated to identify potent new antioxidants. Most of the evaluated compounds showed significant to modest antioxidant properties (IC50 value 399.07 140.0±50 µM. Density Functional Theory (DFT studies were carried out on the compounds and their corresponding free radicals. Differences in the energy of the parent compounds and their corresponding free radicals provided a good justification for the trend found in their IC50 values. In silico, docking of compounds into the proteins acetylcholinesterase (AChE and butyrylcholinesterase (BChE, which are well known for contributing in AD disease, was also performed to predict anti-AD potential.

Design, synthesis and biological evaluation of tacrine-1,2,3-triazole derivatives as potent cholinesterase inhibitors

DEFF Research Database (Denmark)

Wu, Gaochan; Gao, Yun; Kang, Dongwei

2018-01-01

acetylcholinesterase (AChE) and horse serum butyrylcholinesterase (BChE) as potential drug targets for Alzheimer's disease (AD). Among the designed compounds, compound 8a2 exhibited potent inhibition against AChE and BChE with IC50 values of 4.89 μM and 3.61 μM, respectively. Further structure-activity relationship...

Acetylcholinesterase potentiates [3H]fluorowillardiine and [3H]AMPA binding to rat cortical membranes

International Nuclear Information System (INIS)

Olivera, S.; Rodriguez-Ithurralde, D.; Henley, J.M.

1999-01-01

In addition to its action at cholinergic synapses acetylcholinesterase (AChE) has been proposed to modulate neuronal activity by mechanisms unrelated to the hydrolysis of acetylcholine. We have investigated the effects of AChE on the binding of the specific AMPA receptor agonists (S)-[ 3 H]5-fluorowillardiine ([ 3 H]FW) and [ 3 H]AMPA to rat cortical membranes. Pretreatment of membranes with AChE causes a dose-dependent increase in the binding of both radiolabelled agonists with a maximal increase to ∼60% above control. This increase is completely blocked by the specific AChE inhibitors propidium, physostigmine, DFP and BW 284C51. AChE pretreatment had no effect on [ 3 H]kainate binding. [ 3 H]FW binding to membranes from young (15-day-old) rats is four orders of magnitude more sensitive to AChE modulation than membranes from adult rats (EC 50 values of 4x10 -5 and 0.1 unit/ml, respectively) although the total percentage increase in binding is similar. Furthermore, the AChE-induced potentiation of [ 3 H]FW binding is Ca 2+ - and temperature-dependent suggesting an enzymatic action for AChE in this system. Saturation binding experiments with [ 3 H]FW to adult membranes reveal high and low affinity binding sites and demonstrate that the main action of AChE is to increase the B max of both sites. These findings suggest that modulation of AMPA receptors could provide a molecular mechanism of action for the previously reported effects of AChE in synapse formation, synaptic plasticity and neurodegeneration. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

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

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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.

Molecular cloning and characterization of an acetylcholinesterase cDNA in the brown planthopper, Nilaparvata lugens.

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Yang, Zhifan; Chen, Jun; Chen, Yongqin; Jiang, Sijing

2010-01-01

A full cDNA encoding an acetylcholinesterase (AChE, EC 3.1.1.7) was cloned and characterized from the brown planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae). The complete cDNA (2467 bp) contains a 1938-bp open reading frame encoding 646 amino acid residues. The amino acid sequence of the AChE deduced from the cDNA consists of 30 residues for a putative signal peptide and 616 residues for the mature protein with a predicted molecular weight of 69,418. The three residues (Ser242, Glu371, and His485) that putatively form the catalytic triad and the six Cys that form intra-subunit disulfide bonds are completely conserved, and 10 out of the 14 aromatic residues lining the active site gorge of the AChE are also conserved. Northern blot analysis of poly(A)+ RNA showed an approximately 2.6-kb transcript, and Southern blot analysis revealed there likely was just a single copy of this gene in N. lugens. The deduced protein sequence is most similar to AChE of Nephotettix cincticeps with 83% amino acid identity. Phylogenetic analysis constructed with 45 AChEs from 30 species showed that the deduced N. lugens AChE formed a cluster with the other 8 insect AChE2s. Additionally, the hypervariable region and amino acids specific to insect AChE2 also existed in the AChE of N. lugens. The results revealed that the AChE cDNA cloned in this work belongs to insect AChE2 subgroup, which is orthologous to Drosophila AChE. Comparison of the AChEs between the susceptible and resistant strains revealed a point mutation, Gly185Ser, is likely responsible for the insensitivity of the AChE to methamidopho in the resistant strain.

Fumigant toxicity and acetylcholinesterase inhibitory activity of 4 Asteraceae plant essential oils and their constituents against Japanese termite (Reticulitermes speratus Kolbe).

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Seo, Seon-Mi; Kim, Junheon; Kang, Jaesoon; Koh, Sang-Hyun; Ahn, Young-Joon; Kang, Kyu-Suk; Park, Il-Kwon

2014-07-01

This study investigated the fumigant toxicity of 4 Asteraceae plant essential oils and their constituents against the Japanese termite Reticulitermes speratus Kolbe. Fumigant toxicity varied with plant essential oils or constituents, exposure time, and concentration. Among the tested essential oils, those from Chamaemelum nobile exhibited the strongest fumigant toxicity, followed by those from Santolina chamaecyparissus, Ormenis multicaulis, and Eriocephalus punctulatus at 2 days after treatment. In all, 15, 24, 19, and 9 compounds were identified in the essential oils from C. nobile, E. punctulatus, O. multicaulis, and S. chamaecyparissus, respectively, by using gas chromatography, gas chromatography-mass spectrometry, or open-column chromatography. The identified compounds were tested individually for their fumigant toxicity against Japanese termites. Among the test compounds, trans-pinocarveol, caryophyllene oxide, sabinene hydrate, and santolina alcohol showed strong fumigant toxicity against Japanese termites. Acetylcholinesterase (AChE) inhibition activity of the identified compounds from C. nobile, E. punctulatus, O. multicaulis, and S. chamaecyparissus essential oils were tested to determine the mode of their action. The IC50 values of (+)-α-pinene, (-)-limonene, (-)-α-pinene, β-pinene, and β-phellandrene against Japanese termite AChE were 0.03, 0.13, 0.41, 0.42, and 0.67mg/mL, respectively. Further studies are warranted to determine the potential of these essential oils and their constituents as fumigants for termite control. Copyright © 2014 Elsevier Inc. All rights reserved.

Inactivation of JAK2/STAT3 Signaling Axis and Downregulation of M1 mAChR Cause Cognitive Impairment in klotho Mutant Mice, a Genetic Model of Aging

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Park, Seok-Joo; Shin, Eun-Joo; Min, Sun Seek; An, Jihua; Li, Zhengyi; Hee Chung, Yoon; Hoon Jeong, Ji; Bach, Jae-Hyung; Nah, Seung-Yeol; Kim, Won-Ki; Jang, Choon-Gon; Kim, Yong-Sun; Nabeshima, Yo-ichi; Nabeshima, Toshitaka; Kim, Hyoung-Chun

2013-01-01

We previously reported cognitive dysfunction in klotho mutant mice. In the present study, we further examined novel mechanisms involved in cognitive impairment in these mice. Significantly decreased janus kinase 2 (JAK2) and signal transducer and activator of transcription3 (STAT3) phosphorylation were observed in the hippocampus of klotho mutant mice. A selective decrease in protein expression and binding density of the M1 muscarinic cholinergic receptor (M1 mAChR) was observed in these mice. Cholinergic parameters (ie, acetylcholine (ACh), choline acetyltransferase (ChAT), and acetylcholinesterase (AChE)) and NMDAR-dependent long-term potentiation (LTP) were significantly impaired in klotho mutant mice. McN-A-343 (McN), an M1 mAChR agonist, significantly attenuated these impairments. AG490 (AG), a JAK2 inhibitor, counteracted the attenuating effects of McN, although AG did not significantly alter the McN-induced effect on AChE. Furthermore, AG significantly inhibited the attenuating effects of McN on decreased NMDAR-dependent LTP, protein kinase C βII, p-ERK, p-CREB, BDNF, and p-JAK2/p-STAT3-expression in klotho mutant mice. In addition, k252a, a BDNF receptor tyrosine kinase B (TrkB) inhibitor, significantly counteracted McN effects on decreased ChAT, ACh, and M1 mAChR and p-JAK2/p-STAT3 expression. McN-induced effects on cognitive impairment in klotho mutant mice were consistently counteracted by either AG or k252a. Our results suggest that inactivation of the JAK2/STAT3 signaling axis and M1 mAChR downregulation play a critical role in cognitive impairment observed in klotho mutant mice. PMID:23389690

The non-competitive acetylcholinesterase inhibitor APS12-2 is a potent antagonist of skeletal muscle nicotinic acetylcholine receptors

Energy Technology Data Exchange (ETDEWEB)

Grandič, Marjana [Institute of Physiology, Pharmacology and Toxicology, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, SI-1000 Ljubljana (Slovenia); Aráoz, Romulo; Molgó, Jordi [CNRS, Institut de Neurobiologie Alfred Fessard, FRC 2118, Laboratoire de Neurobiologie et Développement, UPR 3294, F-91198 Gif-sur-Yvette Cedex (France); Turk, Tom; Sepčić, Kristina [Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, SI-1000 Ljubljana (Slovenia); Benoit, Evelyne [CNRS, Institut de Neurobiologie Alfred Fessard, FRC 2118, Laboratoire de Neurobiologie et Développement, UPR 3294, F-91198 Gif-sur-Yvette Cedex (France); Frangež, Robert, E-mail: robert.frangez@vf.uni-lj.si [Institute of Physiology, Pharmacology and Toxicology, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, SI-1000 Ljubljana (Slovenia)

2012-12-01

APS12-2, a non-competitive acetylcholinesterase inhibitor, is one of the synthetic analogs of polymeric alkylpyridinium salts (poly-APS) isolated from the marine sponge Reniera sarai. In the present work the effects of APS12-2 were studied on isolated mouse phrenic nerve–hemidiaphragm muscle preparations, using twitch tension measurements and electrophysiological recordings. APS12-2 in a concentration-dependent manner blocked nerve-evoked isometric muscle contraction (IC{sub 50} = 0.74 μM), without affecting directly-elicited twitch tension up to 2.72 μM. The compound (0.007–3.40 μM) decreased the amplitude of miniature endplate potentials until a complete block by concentrations higher than 0.68 μM, without affecting their frequency. Full size endplate potentials, recorded after blocking voltage-gated muscle sodium channels, were inhibited by APS12-2 in a concentration-dependent manner (IC{sub 50} = 0.36 μM) without significant change in the resting membrane potential of the muscle fibers up to 3.40 μM. The compound also blocked acetylcholine-evoked inward currents in Xenopus oocytes in which Torpedo (α1{sub 2}β1γδ) muscle-type nicotinic acetylcholine receptors (nAChRs) have been incorporated (IC{sub 50} = 0.0005 μM), indicating a higher affinity of the compound for Torpedo (α1{sub 2}β1γδ) than for the mouse (α1{sub 2}β1γε) nAChR. Our data show for the first time that APS12-2 blocks neuromuscular transmission by a non-depolarizing mechanism through an action on postsynaptic nAChRs of the skeletal neuromuscular junction. -- Highlights: ► APS12-2 produces concentration-dependent inhibition of nerve-evoked muscle contraction in vitro. ► APS12-2 blocks MEPPs and EPPs at the neuromuscular junction. APS12-2 blocks ACh-activated current in Xenopus oocytes incorporated with Torpedo nAChRs.

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

International Nuclear Information System (INIS)

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

2011-01-01

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.

Esterase metabolism of cholinesterase inhibitors using rat liver in vitro

Science.gov (United States)

A variety of chemicals, such as organophosphate (OP) and carbamate pesticides, nerve agents, and industrial chemicals, inhibit acetylcholinesterase (AChE) leading to overstimulation of the cholinergic nervous system. The resultant neurotoxicity is similar across mammalian species...

The nervus terminalis in the chick: a FMRFamide-immunoreactive and AChE-positive nerve.

Science.gov (United States)

Wirsig-Wiechmann, C R

1990-07-16

The chick terminal nerve (TN) was examined by immunocytochemical and histochemical methods. Molluscan cardioexcitatory peptide-immunoreactive (FMRFamide-ir) and acetylcholinesterase (AChE)-positive TN perikarya and fibers were distributed along olfactory and trigeminal nerves. FMRFamide-ir TN fibers terminated in the olfactory lamina propria and epithelium and in ganglia along the rostroventral nasal septum. This initial description of several populations of avian TN neurons should provide the foundation for future developmental studies of this system.

Hupresin Retains Binding Capacity for Butyrylcholinesterase and Acetylcholinesterase after Sanitation with Sodium Hydroxide

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Seda Onder

2017-10-01

Full Text Available Hupresin is a new affinity resin that binds butyrylcholinesterase (BChE in human plasma and acetylcholinesterase (AChE solubilized from red blood cells (RBC. Hupresin is available from the CHEMFORASE company. BChE in human plasma binds to Hupresin and is released with 0.1 M trimethylammonium bromide (TMA with full activity and 10–15% purity. BChE immunopurified from plasma by binding to immobilized monoclonal beads has fewer contaminating proteins than the one-step Hupresin-purified BChE. However, when affinity chromatography on Hupresin follows ion exchange chromatography at pH 4.5, BChE is 99% pure. The membrane bound AChE, solubilized from human RBC with 0.6% Triton X-100, binds to Hupresin and remains bound during washing with sodium chloride. Human AChE is not released in significant quantities with non-denaturing solvents, but is recovered in 1% trifluoroacetic acid. The denatured, partially purified AChE is useful for detecting exposure to nerve agents by mass spectrometry. Our goal was to determine whether Hupresin retains binding capacity for BChE and AChE after Hupresin is washed with 0.1 M NaOH. A 2 mL column of Hupresin equilibrated in 20 mM TrisCl pH 7.5 was used in seven consecutive trials to measure binding and recovery of BChE from 100 mL human plasma. Between each trial the Hupresin was washed with 10 column volumes of 0.1 M sodium hydroxide. A similar trial was conducted with red blood cell AChE in 0.6% Triton X-100. It was found that the binding capacity for BChE and AChE was unaffected by washing Hupresin with 0.1 M sodium hydroxide. Hupresin could be washed with sodium hydroxide at least seven times without losing binding capacity.

Acetylcholinesterase immobilized capillary reactors coupled to protein coated magnetic beads: A new tool for plant extract ligand screening

OpenAIRE

Vanzolini, Kenia Lourenço; Jiang, Zhengjin; Zhang, Xiaoqi; Vieira, Lucas Campos Curcino; Corrêa, Arlene Gonçalvez; Cardoso, Carmen Lucia; Cass, Quezia Bezerra; Moaddel, Ruin

2013-01-01

The use of immobilized capillary enzyme reactors (ICERs) and enzymes coated to magnetic beads ((NT or CT)-MB) for ligand screening has been adopted as a new technique of high throughput screening (HTS). In this work the selected target was the enzyme acetylcholinesterase (AChE), which acts on the central nervous system and is a validated target for the treatment of Alzheimer’s disease, as well as for new insecticides. A new approach for the screening of plant extracts was developed based on t...

Acetylcholinesterase Inhibitory and Antioxidant Properties of Euphorbiacharacias Latex

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Francesca Pintus

2013-03-01

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

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

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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.

Efficacy of acetylcholinesterase inhibitors versus nootropics in Alzheimer's disease: a retrospective, longitudinal study.

Science.gov (United States)

Tsolaki, M; Pantazi, T; Kazis, A

2001-01-01

The aim of this study was to investigate the efficacy of nootropics (piracetam, aniracetam, nimodopine and dihydroergicristine) versus acetylcholinesterase inhibitors (AChE-Is) (tacrine and donepezil) in the treatment of Alzheimer's disease. This is a retrospective study of 510 patients with Alzheimer's disease. To determine clinical efficacy of treatment, we used the mean change over time in scores for the following tests: the Mini-Mental State Examination (MMSE); the Cambridge Cognitive Examination for the Elderly; and the Functional Rating Scale for Symptoms of Dementia. In all patients and in patients with severe Alzheimer's disease (baseline MMSE nootropics (-4.38 for AChE-Is group versus 1.48 for nootropics group). For patients with mild dementia (baseline MMSE score between 21 and 26), there was a significantly greater deterioration on the MMSE scale for each time-point in the nootropics group compared with the AChE-Is group. In conclusion, we did not find any strong evidence that a difference in efficacy exists between AChE-Is and nootropics in the treatment of Alzheimer's disease.

Novel acetylcholinesterase inhibitors from Zijuan tea and biosynthetic pathway of caffeoylated catechin in tea plant.

Science.gov (United States)

Wang, Wei; Fu, Xi-Wen; Dai, Xin-Long; Hua, Fang; Chu, Gang-Xiu; Chu, Ming-Jie; Hu, Feng-Lin; Ling, Tie-Jun; Gao, Li-Ping; Xie, Zhong-Wen; Wan, Xiao-Chun; Bao, Guan-Hu

2017-12-15

Zijuan tea is a special cultivar of Yunnan broad-leaf tea (Camellia sinensis var. assamica) with purple buds, leaves, and stems. Phytochemical study on this tea led to the discovery of three hydroxycinnamoylated catechins (HCCs) (1-3), seven other catechins (4-10), three proanthocyanidins (11-13), five flavones and flavone glycosides (14-18), two alkaloids (19, 20), one steroid (21), and one phenylpropanoid glycoside (22). The isolation and structural elucidation of the caffeoylated catechin (1) by means of spectroscopic techniques were described. We also provide the first evidence that 1 is synthesized via a two-step pathway in tea plant. The three HCCs (1-3) were investigated on their bioactivity through molecular modeling simulation and biochemical experiments. Our results show that they bind acetylcholinesterase (AChE) tightly and have strong AChE inhibitory activity with IC 50 value at 2.49, 11.41, 62.26μM, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Contrasting genetic influence of PON 1 coding gene polymorphisms ...

African Journals Online (AJOL)

Nadia Youssef Sadek Morcos

2015-03-31

Mar 31, 2015 ... toxicity primarily by inhibiting the enzyme acetylcholinesterase. (AChE) [1]. ... 3. Methods. DNA was extracted from whole blood using a QIAamp Blood .... activity. It is not clear whether this is because of a decreased stability of ...

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

Science.gov (United States)

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

2017-01-01

Hyperlipidemia is a risk factor for the development of cognitive dysfunction and atherosclerosis. Natural compounds have recently received special attention in relation to the treatment of disease due to their low cost and wide margin of safety. Thus, the aim of this study was to determine the possible preventive effect of guarana powder (Paullinia cupana) on memory impairment and acetylcholinesterase (AChE) activity in the brain structures of rats with Poloxamer-407-induced hyperlipidemia. Adult male Wistar rats were pretreated with guarana (12.5, 25 and 50mg/kg/day) and caffeine (0.2mg/kg/day) by gavage for a period of 30days. Simvastatin (0.04mg/kg) was administered as a comparative standard. Acute hyperlipidemia was induced with intraperitoneal injections of 500mg/kg of Poloxamer-407. Memory tests and evaluations of anxiety were performed. The cortex, cerebellum, hippocampus, hypothalamus and striatum were separated to assess acetylcholinesterase activity. Our results revealed that guarana powder was able to reduce the levels of TC and LDL-C in a manner similar to simvastatin. Guarana powder also partially reduced the liver damage caused by hyperlipidemia. Guarana was able to prevent changes in the activity of AChE and improve memory impairment due to hyperlipidemia. Guarana powder may therefore be a source of promising phytochemicals that can be used as adjuvant therapy in the management of hyperlipidemia and cognitive disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

New derivatives of 3,4-dihydroisoquinoline-3-carboxylic acid with free-radical scavenging, D-amino acid oxidase, acetylcholinesterase and butyrylcholinesterase inhibitory activity.

Science.gov (United States)

Solecka, Jolanta; Guśpiel, Adam; Postek, Magdalena; Ziemska, Joanna; Kawęcki, Robert; Lęczycka, Katarzyna; Osior, Agnieszka; Pietrzak, Bartłomiej; Pypowski, Krzysztof; Wyrzykowska, Agata

2014-09-30

A series of 3,4-dihydroisoquinoline-3-carboxylic acid derivatives were synthesised and tested for their free-radical scavenging activity using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH·), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS·+), superoxide anion radical (O2·-) and nitric oxide radical (·NO) assays. We also studied d-amino acid oxidase (DAAO), acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activity. Almost each of newly synthesised compounds exhibited radical scavenging capabilities. Moreover, several compounds showed moderate inhibitory activities against DAAO, AChE and BuChE. Compounds with significant free-radical scavenging activity may be potential candidates for therapeutics used in oxidative-stress-related diseases.

In silico development of new acetylcholinesterase inhibitors.

Science.gov (United States)

Pascoini, A L; Federico, L B; Arêas, A L F; Verde, B A; Freitas, P G; Camps, I

2018-04-19

In this work, we made use of fragment-based drug design (FBDD) and de novo design to obtain more powerful acetylcholinesterase (AChE) inhibitors. AChE is associated with Alzheimer's disease (AD). It was found that the cholinergic pathways in the cerebral cortex are compromised in AD and the accompanying cholinergic deficiency contributes to the cognitive deterioration of AD patients. In the FBDD approach, fragments are docked into the active site of the protein. As fragments are molecular groups with a low number of atoms, it is possible to study their interaction with localized amino acids. Once the interactions are measured, the fragments are organized by affinity and then linked together to form new molecules with a high degree of interaction with the active site. In the other approach, we used the de novo design technique starting from reference drugs used in the AD treatment. These drugs were broken into fragments (seeds). In the growing strategy, fragments were added to each seed, growing new molecules. In the linking strategy, two or more separated seeds were linked with different fragments. Both strategies combined produced a library of more than 2 million compounds. This library was filtered using absorption, distribution, metabolism, and excretion properties. The resulting library with around six thousand compounds was filtered again. In this case, structures with Tanimoto coefficients >.85 were discarded. The final library with 1500 compounds was submitted to docking studies. As a result, 10 compounds with better interaction energy than the reference drugs were obtained.

Selenofuranoside Ameliorates Memory Loss in Alzheimer-Like Sporadic Dementia: AChE Activity, Oxidative Stress, and Inflammation Involvement

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Cristiano Chiapinotto Spiazzi

2015-01-01

Full Text Available Alzheimer’s disease (AD is becoming more common due to the increase in life expectancy. This study evaluated the effect of selenofuranoside (Se in an Alzheimer-like sporadic dementia animal model. Male mice were divided into 4 groups: control, Aβ, Se, and Aβ + Se. Single administration of Aβ peptide (fragments 25–35; 3 nmol/3 μL or distilled water was administered via intracerebroventricular (i.c.v. injection. Selenofuranoside (5 mg/kg or vehicle (canola oil was administered orally 30 min before Aβ and for 7 subsequent days. Memory was tested through the Morris water maze (MWM and step-down passive-avoidance (SDPA tests. Antioxidant defenses along with reactive species (RS were assessed. Inflammatory cytokines levels and AChE activity were measured. SOD activity was inhibited in the Aβ group whereas RS were increased. AChE activity, GSH, and IL-6 levels were increased in the Aβ group. These changes were reflected in impaired cognition and memory loss, observed in both behavioral tests. Se compound was able to protect against memory loss in mice in both behavioral tests. SOD and AChE activities as well as RS and IL-6 levels were also protected by Se administration. Therefore, Se is promising for further studies.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Wnt3a induces the expression of acetylcholinesterase during osteoblast differentiation via the Runx2 transcription factor.

Science.gov (United States)

Xu, Miranda L; Bi, Cathy W C; Liu, Etta Y L; Dong, Tina T X; Tsim, Karl W K

2017-07-28

Acetylcholinesterase (AChE) hydrolyzes acetylcholine to terminate cholinergic transmission in neurons. Apart from this AChE activity, emerging evidence suggests that AChE could also function in other, non-neuronal cells. For instance, in bone, AChE exists as a proline-rich membrane anchor (PRiMA)-linked globular form in osteoblasts, in which it is proposed to play a noncholinergic role in differentiation. However, this hypothesis is untested. Here, we found that in cultured rat osteoblasts, AChE expression was increased in parallel with osteoblastic differentiation. Because several lines of evidence indicate that AChE activity in osteoblast could be triggered by Wnt/β-catenin signaling, we added recombinant human Wnt3a to cultured osteoblasts and found that this addition induced expression of the ACHE gene and protein product. This Wnt3a-induced AChE expression was blocked by the Wnt-signaling inhibitor Dickkopf protein-1 (DKK-1). We hypothesized that the Runt-related transcription factor 2 (Runx2), a downstream transcription factor in Wnt/β-catenin signaling, is involved in AChE regulation in osteoblasts, confirmed by the identification of a Runx2-binding site in the ACHE gene promoter, further corroborated by ChIP. Of note, Runx2 overexpression in osteoblasts induced AChE expression and activity of the ACHE promoter tagged with the luciferase gene. Moreover, deletion of the Runx2-binding site in the ACHE promoter reduced its activity during osteoblastic differentiation, and addition of 5-azacytidine and trichostatin A to differentiating osteoblasts affected AChE expression, suggesting epigenetic regulation of the ACHE gene. We conclude that AChE plays a role in osteoblastic differentiation and is regulated by both Wnt3a and Runx2. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Small Quaternary Inhibitors K298 and K524: Cholinesterases Inhibition, Absorption, Brain Distribution, and Toxicity.

Science.gov (United States)

Karasova, Jana Zdarova; Hroch, Milos; Musilek, Kamil; Kuca, Kamil

2016-02-01

Inhibitors of acetylcholinesterase (AChE) may be used in the treatment of various cholinergic deficits, among them being myasthenia gravis (MG). This paper describes the first in vivo data for promising small quaternary inhibitors (K298 and K524): acute toxicity study, cholinesterase inhibition, absorption, and blood-brain barrier penetration. The newly prepared AChE inhibitors (bis-quinolinium and quinolinium compounds) possess a positive charge in the molecule which ensures that anti-AChE action is restricted to peripheral effect. HPLC-MS was used for determination of real plasma and brain concentration in the pharmacokinetic part of the study, and standard non-compartmental analysis was performed. The maximum plasma concentrations were attained at 30 min (K298; 928.76 ± 115.20 ng/ml) and 39 min (K524; 812.40 ± 54.96 ng/ml) after i.m. Both compounds are in fact able to target the central nervous system. It seems that the difference in the CNS distribution profile depends on an active efflux system. The K524 brain concentration was actively decreased to below an effective level; in contrast, K298 progressively accumulated in brain tissue. Peripheral AChE inhibitors are still first-line treatment in the mild forms of MG. Commonly prescribed carbamates have many severe side effects related to AChE carbamylation. The search for new treatment strategies is still important. Unlike carbamates, these new compounds target AChE via apparent π-π or π-cationic interaction aside at the AChE catalytic site.

Differentiated NSC-34 cells as an in vitro Cell Model for VX

Science.gov (United States)

2014-09-11

principally as potent cholinesterase inhibitors . The toxicity of these compounds and their mode of action are attributed to the inhibition of the enzyme...necrosis, with more cells undergoing apoptosis. Acetylcholinesterase inhibition by VX Since VX is an AChE inhibitor , the amount of VX-induced AChE...acetyl- cholinesterase by in vitro methods. Acta Medica (Hradec Kralove) 48:81–6. Landshamer S, Hoehn M, Barth N, et al. (2008). Bid-induced release of

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

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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

Comparative study of acetylcholinesterase and glutathione S-transferase activities of closely related cave and surface Asellus aquaticus (Isopoda: Crustacea.

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Anita Jemec

Full Text Available The freshwater isopod crustacean Asellus aquaticus has recently been developed as an emerging invertebrate cave model for studying evolutionary and developmental biology. Mostly morphological and genetic differences between cave and surface A. aquaticus populations have been described up to now, while scarce data are available on other aspects, including physiology. The purpose of this study was to advance our understanding of the physiological differences between cave A. aquaticus and its surface-dwelling counterparts. We sampled two surface populations from the surface section of the sinking Pivka River (central Slovenia, Europe, i.e. locality Pivka Polje, and locality Planina Polje, and one cave population from the subterranean section of the sinking Pivka River, i.e. locality Planina Cave. Animals were sampled in spring, summer and autumn. We measured the activities of acetylcholinesterase (AChE and glutathione S-transferase (GST in individuals snap-frozen in the field immediately after collection. Acetylcholinesterase is likely related to animals' locomotor activity, while GST activity is related to the metabolic activity of an organism. Our study shows significantly lower AChE and GST activities in the cave population in comparison to both surface A. aquaticus populations. This confirms the assumption that cave A. aquaticus have lower locomotor and metabolic activity than surface A. aquaticus in their respective natural environments. In surface A. aquaticus populations, seasonal fluctuations in GST activity were observed, while these were less pronounced in individuals from the more stable cave environment. On the other hand, AChE activity was generally season-independent in all populations. To our knowledge, this is the first study of its kind conducted in A. aquaticus. Our results show that among closely related cave and surface A. aquaticus populations also physiological differences are present besides the morphological and genetic

Acetylcholinesterase activity, cohabitation with floricultural workers, and blood pressure in Ecuadorian children.

Science.gov (United States)

Suarez-Lopez, Jose R; Jacobs, David R; Himes, John H; Alexander, Bruce H

2013-05-01

Acetylcholinesterase (AChE) inhibitors are commonly used pesticides that can effect hemodynamic changes through increased cholinergic stimulation. Children of agricultural workers are likely to have paraoccupational exposures to pesticides, but the potential physiological impact of such exposures is unclear. We investigated whether secondary pesticide exposures were associated with blood pressure and heart rate among children living in agricultural Ecuadorian communities. This cross-sectional study included 271 children 4-9 years of age [51% cohabited with one or more flower plantation workers (mean duration, 5.2 years)]. Erythrocyte AChE activity was measured using the EQM Test-mate system. Linear regression models were used to estimate associations of systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate with AChE activity, living with flower workers, duration of cohabitation with a flower worker, number of flower workers in the child's home, and number of practices that might increase children's exposure to pesticides. Mean (± SD) AChE activity was 3.14 ± 0.49 U/mL. A 1-U/mL decrease in AChE activity was associated with a 2.86-mmHg decrease in SBP (95% CI: -5.20, -0.53) and a 2.89-mmHg decrease in DBP (95% CI: -5.00, -0.78), after adjustment for potential confounders. Children living with flower workers had lower SBP (-1.72 mmHg; 95% CI: -3.53, 0.08) than other children, and practices that might increase exposure also were associated with lower SBP. No significant associations were found between exposures and heart rate. Our findings suggest that subclinical secondary exposures to pesticides may affect vascular reactivity in children. Additional research is needed to confirm these findings.

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

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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.

Acetylcholinesterase potentiates [{sup 3}H]fluorowillardiine and [{sup 3}H]AMPA binding to rat cortical membranes

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Olivera, S.; Rodriguez-Ithurralde, D. [Department of Anatomy, School of Medical Sciences, University of Bristol, University Walk, Bristol, BS8 1TD (United Kingdom); Henley, J.M. [Molecular Neuroscience Unit, Division Neuromyology, Instituto de Investigaciones Biologicas Clemente Estable, 11600 Montevideo (Uruguay)

1999-04-01

In addition to its action at cholinergic synapses acetylcholinesterase (AChE) has been proposed to modulate neuronal activity by mechanisms unrelated to the hydrolysis of acetylcholine. We have investigated the effects of AChE on the binding of the specific AMPA receptor agonists (S)-[{sup 3}H]5-fluorowillardiine ([{sup 3}H]FW) and [{sup 3}H]AMPA to rat cortical membranes. Pretreatment of membranes with AChE causes a dose-dependent increase in the binding of both radiolabelled agonists with a maximal increase to {approx}60% above control. This increase is completely blocked by the specific AChE inhibitors propidium, physostigmine, DFP and BW 284C51. AChE pretreatment had no effect on [{sup 3}H]kainate binding. [{sup 3}H]FW binding to membranes from young (15-day-old) rats is four orders of magnitude more sensitive to AChE modulation than membranes from adult rats (EC{sub 50} values of 4x10{sup -5} and 0.1 unit/ml, respectively) although the total percentage increase in binding is similar. Furthermore, the AChE-induced potentiation of [{sup 3}H]FW binding is Ca{sup 2+}- and temperature-dependent suggesting an enzymatic action for AChE in this system. Saturation binding experiments with [{sup 3}H]FW to adult membranes reveal high and low affinity binding sites and demonstrate that the main action of AChE is to increase the B{sub max} of both sites. These findings suggest that modulation of AMPA receptors could provide a molecular mechanism of action for the previously reported effects of AChE in synapse formation, synaptic plasticity and neurodegeneration. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Theoretical NMR and conformational analysis of solvated oximes for organophosphates-inhibited acetylcholinesterase reactivation

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da Silva, Jorge Alberto Valle; Modesto-Costa, Lucas; de Koning, Martijn C.; Borges, Itamar; França, Tanos Celmar Costa

2018-01-01

In this work, quaternary and non-quaternary oximes designed to bind at the peripheral site of acetylcholinesterase previously inhibited by organophosphates were investigated theoretically. Some of those oximes have a large number of degrees of freedom, thus requiring an accurate method to obtain molecular geometries. For this reason, the density functional theory (DFT) was employed to refine their molecular geometries after conformational analysis and to compare their 1H and 13C nuclear magnetic resonance (NMR) theoretical signals in gas-phase and in solvent. A good agreement with experimental data was achieved and the same theoretical approach was employed to obtain the geometries in water environment for further studies.

Molecular assembly and biosynthesis of acetylcholinesterase in brain and muscle: The roles of t-peptide, FHB domain and N-linked glycosylation

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Vicky P. Chen

2011-10-01

Full Text Available Acetylcholinesterase (AChE is responsible for the hydrolysis of the neurotransmitter, acetylcholine, in the nervous system. The functional localization and oligomerization of AChE T variant are depending primarily on the association of their anchoring partners, either collagen tail (ColQ or proline rich membrane anchor (PRiMA. Complexes with ColQ represent the asymmetric forms (A12 in muscle, while complexes with PRiMA represent tetrameric globular forms (G4 mainly found in brain and muscle. Apart from these traditional molecular forms, a ColQ-linked asymmetric form and a PRiMA-linked globular form of hybrid cholinesterases (ChEs, having both AChE and BChE catalytic subunits, were revealed in chicken brain and muscle. The similarity of various molecular forms of AChE and BChE raises interesting question regarding to their possible relationship in enzyme assembly and localization. The focus of this review is to provide current findings about the biosynthesis of different forms of ChEs together with their anchoring proteins.

Colletotrichine A, a new sesquiterpenoid from Colletotrichum gloeosporioides GT-7, a fungal endophyte of Uncaria rhynchophylla.

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Chen, Xiao-Wei; Yang, Zhong-Duo; Sun, Jian-Hui; Song, Tong-Tong; Zhu, Bao-Ying; Zhao, Jun-Wen

2018-04-01

One new compound, Colletotrichine A (1), was produced by the fungal Colletotrichum gloeosporioides GT-7. The structure was established by 1D and 2D NMR spectra. Monoamine oxidase (MAO) and acetylcholinesterase (AChE) inhibitory activity of 1 was also evaluated. Compound 1 showed AChE-inhibiting activity with IC 50 value of 28 μg/mL.

The effect of curcumin in the ectonucleotidases and acetylcholinesterase activities in synaptosomes from the cerebral cortex of cigarette smoke-exposed rats.

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Jaques, Jeandre Augusto Dos Santos; Rezer, João Felipe Peres; Gonçalves, Jamile Fabbrin; Spanevello, Rosélia Maria; Gutierres, Jessié Martins; Pimentel, Victor Câmera; Thomé, Gustavo Roberto; Morsch, Vera Maria; Schetinger, Maria Rosa Chitolina; Leal, Daniela Bitencourt Rosa

2011-12-01

With the evidence that curcumin may be a potent neuroprotective agent and that cigarette smoke is associated with a decline in the cognitive performance as our bases, we investigated the activities of Ecto-Nucleoside Triphosphate Diphosphohydrolase (NTPDase), 5'-nucleotidase and acetylcholinesterase (AChE) in cerebral cortex synaptosomes from cigarette smoke-exposed rats treated with curcumin (Cur). The experimental procedures entailed two sets of experiments. In the first set, the groups were vehicle, Cur 12·5, 25 and 50 mg·kg(-1) ; those in the second set were vehicle, smoke, smoke and Cur 12·5, 25 and 50 mg·kg(-1) . Curcumin prevented the increased NTPDase, 5'-nucleotidase and AChE activities caused by smoke exposure. We suggest that treatment with Cur was protective because the decrease of ATP and acetylcholine (ACh) concentrations is responsible for cognitive impairment, and both ATP and ACh have key roles in neurotransmission. Copyright © 2011 John Wiley & Sons, Ltd.

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

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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.

Japanese Encephalitis Virus Infection Results in Transient Dysfunction of Memory Learning and Cholinesterase Inhibition.

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Chauhan, Prashant Singh; Khanna, Vinay Kumar; Kalita, Jayantee; Misra, Usha Kant

2017-08-01

Cholinergic system has an important role in memory and learning. Abnormal cognitive and behavioral changes have been reported in Japanese encephalitis (JE), but their basis has not been comprehensively evaluated. In this study, we report memory and learning and its association with acetylcholinesterase (AChE) activity, JE virus titer, and with histopathological observations in a rat model of JE. Wistar rats were intracerebrally inoculated on 12th day with 3 × 10 6  pfu/ml of JE virus. Memory and learning were assessed by the active and passive avoidance tests on 10, 33, and 48 days post inoculation (dpi). After 10, 33, and 48 dpi AChE activity, Japanese encephalitis virus (JEV) titer and histopathological changes were studied in the frontal cortex, thalamus, midbrain, cerebellum, and hippocampus. There was significant impairment in memory and learning on 10 dpi which started improving from 33 dpi to 48 dpi by active avoidance test. Passive avoidance test showed decrease in transfer latency time of retention trial compared to acquisition on first, second, and third retention day trial compared to controls. AChE inhibition was more marked in the hippocampus, frontal cortex, and cerebellum on 10 dpi. However, AChE activity started improving from 33 dpi to 48 dpi. AChE activity in the thalamus and midbrain correlated with active avoidance test on 10 dpi and 33 dpi. Histopathological studies also revealed improvement on 33 and 48 compared to 10 dpi. The present study demonstrates transient memory and learning impairment which was associated with reduction in AChE, JEV titer, and damage in different brain regions of JEV infected rats.

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

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Zaĭtseva, O V; Kuznetsova, T V

2008-01-01

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

In vitro screening for anti-cholinesterase and antioxidant activity of methanolic extracts of ayurvedic medicinal plants used for cognitive disorders.

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Maya Mathew

Full Text Available Inhibition of Acetylcholinesterase (AChE is still considered as the main therapeutic strategy against Alzheimer's disease (AD. Many plant derived phytochemicals have shown AChE inhibitory activity in addition to the currently approved drugs for AD. In the present study, methanolic extracts of 20 plants used in Indian Ayurvedic system of medicine for improving cognitive function were screened for acetylcholinesterase inhibitory activity by Ellman's microplate colorimetric method. Out of 20 extracts, Emblica officinalis, Nardostachys jatamansi, Nelumbo nucifera, Punica granatum and Raulfia Serpentina showed IC50 values <100 µg/ml for acetylcholinesterase inhibitory activity. Antioxidant activities of these plants were assessed by DPPH scavenging assay. Among the extracts used, antioxidant activity was highest for Terminalia chebula and Emblica officinalis with IC50 values <10 µg/ml. Considering the complex multifactorial etiology of AD, these plant extracts will be safer and better candidates for the future disease modifying therapies against this devastating disease.

In Vitro Screening for Anti-Cholinesterase and Antioxidant Activity of Methanolic Extracts of Ayurvedic Medicinal Plants Used for Cognitive Disorders

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Mathew, Maya; Subramanian, Sarada

2014-01-01

Inhibition of Acetylcholinesterase (AChE) is still considered as the main therapeutic strategy against Alzheimer’s disease (AD). Many plant derived phytochemicals have shown AChE inhibitory activity in addition to the currently approved drugs for AD. In the present study, methanolic extracts of 20 plants used in Indian Ayurvedic system of medicine for improving cognitive function were screened for acetylcholinesterase inhibitory activity by Ellman’s microplate colorimetric method. Out of 20 extracts, Emblica officinalis, Nardostachys jatamansi, Nelumbo nucifera, Punica granatum and Raulfia Serpentina showed IC50 values <100 µg/ml for acetylcholinesterase inhibitory activity. Antioxidant activities of these plants were assessed by DPPH scavenging assay. Among the extracts used, antioxidant activity was highest for Terminalia chebula and Emblica officinalis with IC50 values <10 µg/ml. Considering the complex multifactorial etiology of AD, these plant extracts will be safer and better candidates for the future disease modifying therapies against this devastating disease. PMID:24466247

Proline-induced changes in acetylcholinesterase activity and gene expression in zebrafish brain: reversal by antipsychotic drugs.

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Savio, L E B; Vuaden, F C; Kist, L W; Pereira, T C; Rosemberg, D B; Bogo, M R; Bonan, C D; Wyse, A T S

2013-10-10

Hyperprolinemia is an inherited disorder of proline metabolism and hyperprolinemic patients can present neurological manifestations, such as seizures, cognitive dysfunctions, and schizoaffective disorders. However, the mechanisms related to these symptoms are still unclear. In the present study, we evaluated the in vivo and in vitro effects of proline on acetylcholinesterase (AChE) activity and gene expression in the zebrafish brain. For the in vivo studies, animals were exposed at two proline concentrations (1.5 and 3.0mM) during 1h or 7 days (short- or long-term treatments, respectively). For the in vitro assays, different proline concentrations (ranging from 3.0 to 1000 μM) were tested. Long-term proline exposures significantly increased AChE activity for both treated groups when compared to the control (34% and 39%). Moreover, the proline-induced increase on AChE activity was completely reverted by acute administration of antipsychotic drugs (haloperidol and sulpiride), as well as the changes induced in ache expression. When assessed in vitro, proline did not promote significant changes in AChE activity. Altogether, these data indicate that the enzyme responsible for the control of acetylcholine levels might be altered after proline exposure in the adult zebrafish. These findings contribute for better understanding of the pathophysiology of hyperprolinemia and might reinforce the use of the zebrafish as a complementary vertebrate model for studying inborn errors of amino acid metabolism. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

Synthesis and evaluation of 6-[11C]Methoxy-3-[2- [1-(phenylmethyl)-4-piperidinyl]ethyl]-1,2-benzisoxazole as an in vivo radioligand for acetylcholinesterase

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Brown-Proctor, Clive; Snyder, Scott E.; Sherman, Phillip S.; Kilbourn, Michael R.

1999-01-01

6-Methoxy-3-[2-[1-(phenylmethyl)-4-piperidinyl]ethyl]-1,2-benzisoxazole is a high affinity (K i =8.2 nM) reversible inhibitor of acetylcholinesterase (AChE). The carbon-11 labeled form was prepared in high (>97%) radiochemical purity and with specific activities of 37 ± 20 GBq/μmol at end of synthesis, by the alkylation of the desmethyl precursor with [ 11 C]methyl trifluoromethanesulfonate in N,N-dimethylformamide at room temperature. In vivo studies in mice demonstrated good blood brain permeability but essentially uniform regional brain distribution. Thus, despite in vitro and in vivo activity as an AChE inhibitor, 6-[ 11 C]methoxy-3-[2-[1-(phenylmethyl)-4-piperidinyl]ethyl]-1, 2-benzisoxazole does not appear to be a good candidate for in vivo imaging studies of AChE in the mammalian brain

Acetylcholinesterase biosensor based on SnO2 nanoparticles-carboxylic graphene-nafion modified electrode for detection of pesticides.

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Zhou, Qing; Yang, Long; Wang, Guangcan; Yang, Yun

2013-11-15

A sensitive amperometric acetylcholinesterase (AChE) biosensor, based on SnO2 nanoparticles (SnO2 NPs), carboxylic graphene (CGR) and nafion (NF) modified glassy carbon electrode (GCE) for the detection of methyl parathion and carbofuran has been developed. The nanocomposites of SnO2 NPs and CGR was synthesized and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), respectively. Chitosan (CS) was used to immobilize AChE on SnO2 NPs-CGR-NF/GCE and to improve electronic transmission between AChE and SnO2 NPs-CGR-NF/GCE. NF was used as the protective membrane for the AChE biosensor. The SnO2 NPs-CGR-NF nanocomposites with excellent conductivity, catalysis and biocompatibility offered an extremely hydrophilic surface for AChE adhesion. The AChE biosensor showed favorable affinity to acetylthiocholine chloride (ATCl) and could catalyze the hydrolysis of ATCl with an apparent Michaelis-Menten constant value of 131 μM. The biosensor detected methyl parathion in the linear range from 10(-13) to 10(-10)M and from 10(-10) to 10(-8)M. The biosensor detected carbofuran in the linear range from 10(-12) to 10(-10)M and from 10(-10) to 10(-8)M. The detection limits of methyl parathion and carbofuran were 5 × 10(-14)M and 5 × 10(-13)M, respectively. The biosensor exhibited low applied potential, high sensitivity and acceptable stability, thus providing a promising tool for analysis of pesticides. Copyright © 2013 Elsevier B.V. All rights reserved.

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

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Ahmad Mohammadi-Farani

2017-01-01

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

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

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Arruda, Miguel; Viana, Hugo; Rainha, Nuno; Neng, Nuno R.; Rosa, José Silvino; Nogueira, José M. F.; Barreto, Maria do Carmo

2012-01-01

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 composi...

Synthesis of a Pilot Scale Library of 4-amino-2 (diethylaminomethyl) phenol (ADOC) Analogues for Testing of Organophosphate-Inhibited Acetylcholinesterase Reactivation Ability

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2018-02-01

Inhibited Acetylcholinesterase Reactivation Ability Zachary Canter Kevin Martin Michael Hepperle February 2018 Approved for public release; distribution...PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Canter, Z., Martin , K., Hepperle, M. 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING

The inhibition, reactivation and mechanism of VX-, sarin-, fluoro-VX and fluoro-sarin surrogates following their interaction with HuAChE and HuBuChE.

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Chao, Chih-Kai; Balasubramanian, Narayanaganesh; Gerdes, John M; Thompson, Charles M

2018-06-16

In this study, the mechanisms of HuAChE and HuBChE inhibition by Me-P(O) (OPNP) (OR) [PNP = p-nitrophenyl; R = CH 2 CH 3 , CH 2 CH 2 F, OCH(CH 3 ) 2 , OCH(CH 3 ) (CH 2 F)] representing surrogates and fluoro-surrogates of VX and sarin were studied by in vitro kinetics and mass spectrometry. The in vitro measures showed that the VX- and fluoro-VX surrogates were relatively strong inhibitors of HuAChE and HuBChE (k i  ∼ 10 5 -10 6  M -1 min -1 ) and underwent spontaneous and 2-PAM-mediated reactivation within 30 min. The sarin surrogates were weaker inhibitors of HuAChE and HuBChE (k i  ∼ 10 4 -10 5  M -1 min -1 ), and in general did not undergo spontaneous reactivation, although HuAChE adducts were partially reactivatable at 18 h using 2-PAM. The mechanism of HuAChE and HuBChE inhibition by the surrogates was determined by Q-TOF and MALDI-TOF mass spectral analyses. The surrogate-adducted proteins were trypsin digested and the active site-containing peptide bearing the OP-modified serine identified by Q-TOF as triply- and quadruply-charged ions representing the respective increase in mass of the attached OP moiety. Correspondingly, monoisotopic ions of the tryptic peptides representing the mass increase of the OP-adducted peptide was identified by MALDI-TOF. The mass spectrometry analyses validated the identity of the OP moiety attached to HuAChE or HuBChE as MeP(O) (OR)-O-serine peptides (loss of the PNP leaving group) via mechanisms consistent with those found with chemical warfare agents. MALDI-TOF MS analyses of the VX-modified peptides versus time showed a steady reduction in adduct versus parent peptide (reactivation), whereas the sarin-surrogate-modified peptides remained largely intact over the course of the experiment (24 h). Overall, the presence of a fluorine atom on the surrogate modestly altered the rate constants of inhibition and reactivation, however, the mechanism of inhibition (ejection of PNP group) did not change

Exposure to radio-frequency electromagnetic waves alters acetylcholinesterase gene expression, exploratory and motor coordination-linked behaviour in male rats.

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Obajuluwa, Adejoke Olukayode; Akinyemi, Ayodele Jacob; Afolabi, Olakunle Bamikole; Adekoya, Khalid; Sanya, Joseph Olurotimi; Ishola, Azeez Olakunle

2017-01-01

Humans in modern society are exposed to an ever-increasing number of electromagnetic fields (EMFs) and some studies have demonstrated that these waves can alter brain function but the mechanism still remains unclear. Hence, this study sought to investigate the effect of 2.5 Ghz band radio-frequency electromagnetic waves (RF-EMF) exposure on cerebral cortex acetylcholinesterase (AChE) activity and their mRNA expression level as well as locomotor function and anxiety-linked behaviour in male rats. Animals were divided into four groups namely; group 1 was control (without exposure), group 2-4 were exposed to 2.5 Ghz radiofrequency waves from an installed WI-FI device for a period of 4, 6 and 8 weeks respectively. The results revealed that WiFi exposure caused a significant increase in anxiety level and affect locomotor function. Furthermore, there was a significant decrease in AChE activity with a concomitant increase in AChE mRNA expression level in WiFi exposed rats when compared with control. In conclusions, these data showed that long term exposure to WiFi may lead to adverse effects such as neurodegenerative diseases as observed by a significant alteration on AChE gene expression and some neurobehavioral parameters associated with brain damage.

Synthesis and evaluation of 6-[{sup 11}C]Methoxy-3-[2- [1-(phenylmethyl)-4-piperidinyl]ethyl]-1,2-benzisoxazole as an in vivo radioligand for acetylcholinesterase

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Brown-Proctor, Clive; Snyder, Scott E.; Sherman, Phillip S.; Kilbourn, Michael R. E-mail: mkilbour@umich.edu

1999-01-01

6-Methoxy-3-[2-[1-(phenylmethyl)-4-piperidinyl]ethyl]-1,2-benzisoxazole is a high affinity (K{sub i}=8.2 nM) reversible inhibitor of acetylcholinesterase (AChE). The carbon-11 labeled form was prepared in high (>97%) radiochemical purity and with specific activities of 37 {+-} 20 GBq/{mu}mol at end of synthesis, by the alkylation of the desmethyl precursor with [{sup 11}C]methyl trifluoromethanesulfonate in N,N-dimethylformamide at room temperature. In vivo studies in mice demonstrated good blood brain permeability but essentially uniform regional brain distribution. Thus, despite in vitro and in vivo activity as an AChE inhibitor, 6-[{sup 11}C]methoxy-3-[2-[1-(phenylmethyl)-4-piperidinyl]ethyl]-1, 2-benzisoxazole does not appear to be a good candidate for in vivo imaging studies of AChE in the mammalian brain.

Expression and evolutionary analyses of three acetylcholinesterase genes (Mi-ace-1, Mi-ace-2, Mi-ace-3) in the root-knot nematode Meloidogyne incognita.

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Cui, Ruqiang; Zhang, Lei; Chen, Yuyan; Huang, Wenkun; Fan, Chengming; Wu, Qingsong; Peng, Deliang; da Silva, Washington; Sun, Xiaotang

2017-05-01

The full cDNA of Mi-ace-3 encoding an acetylcholinesterase (AChE) in Meloidogyne incognita was cloned and characterized. Mi-ace-3 had an open reading frame of 1875 bp encoding 624 amino acid residues. Key residues essential to AChE structure and function were conserved. The deduced Mi-ACE-3 protein sequence had 72% amino acid similarity with that of Ditylenchus destructor Dd-AChE-3. Phylogenetic analyses using 41 AChEs from 24 species showed that Mi-ACE-3 formed a cluster with 4 other nematode AChEs. Our results revealed that the Mi-ace-3 cloned in this study, which is orthologous to Caenorhabditis elegans AChE, belongs to the nematode ACE-3/4 subgroup. There was a significant reduction in the number of galls in transgenic tobacco roots when Mi-ace-1, Mi-ace-2, and Mi-ace-3 were knocked down simultaneously, whereas little or no effect were observed when only one or two of these genes were knocked down. This is an indication that the functions of these three genes are redundant. Copyright © 2017. Published by Elsevier Inc.

A Green Method for Synthesis of 7H-thiazolo[3,2-b][1,2, 4]-triazin-7-one Derivatives as AChE Inhibitors

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Liu Sijie

2015-01-01

Full Text Available The authors study an efficient and green approach for the synthesis of 7H-thiazolo [3, 2-b][1,2,4]triazin-7-one derivatives as AChE inhibitors. The 7H-thiazolo[3,2-b][1,2,4]triazin-7-ones were designed by molecular docking, and readily prepared via a one-pot reaction in morpholine hydrosulfate ([Hnhm]HSO4 lonic liquid as the catalyst and solvent. The study of AChE inhibitory activity was carried out through using the Ellman colorimetric assay. The 7H-thiazolo[3,2-b][1,2,4]triazin-7-ones had been successfully synthesized by green catalyst. Most of the target compounds exhibited more than 50% inhibition at 10μM.

Acetylcholinesterase activity in seabirds affected by the Prestige oil spill on the Galician coast (Spain)

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Oropesa, Ana-Lourdes; Perez-Lopez, Marcos; Hernandez, David; Soler, Francisco [Toxicology Area, Faculty of Veterinary Science (UEX), Avda. de la Universidad s/n. 10071 Caceres (Spain); Garcia, Jesus-Pablo [Toxicology Area, National Centre of Environmental Health, Instituto de Salud Carlos III, Majadahonda, Madrid (Spain); Fidalgo, Luis-Eusebio; Lopez-Beceiro, Ana [Rof Codina Clinical Hospital, Faculty of Veterinary Science (USC), Estrada de Granxa s/n. 27003 Lugo (Spain)

2007-01-01

In November 2002, the tanker Prestige broke in two and sank at the bottom of the ocean spilling about 70,000 t of fuel oil, which reached the coast of Galicia. It was considered the largest spill in maritime history, greatly affecting marine and related avian species. The spilled fuel oil contained high concentrations of polycyclic aromatic hydrocarbons (PAHs). Many species were affected and were found dead, although ongoing research is still being carried out on the sublethal effects. In this sense, little is known about the action of PAHs on Cholinesterase activity in seabirds. Consequently, the purpose of this study was to provide more information on the neurotoxicity of fuel oil on the seabirds most affected by the Prestige accident: common guillemot, Atlantic puffin and razorbill. On the other hand, data on normal values of acetylcholinesterase (AChE) activity were obtained to supply non-exposed values in seabirds. The oil spill produced a clear inhibitory effect on brain AChE activity in common guillemot (16%, p {<=} 0.01) and razorbill (22%, p {<=} 0.01), but not in Atlantic puffin (4%). Physiological levels of brain AChE, expressed in nmol acetylcholine hydrolysed min{sup -} {sup 1} mg{sup -} {sup 1} protein were similar in non-exposed common guillemot (388.6 {+-} 95.0) and Atlantic puffin (474.0 {+-} 60.7), however, razorbill values were higher (644.6 {+-} 66.9). (author)

Two Step Synthesis of a Non-symmetric Acetylcholinesterase Reactivator

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Vit Koleckar

2007-08-01

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

[Design, synthesis and evaluation of bis-nicotine derivatives as inhibitors of cholinesterases and beta-amyloid aggregation].

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Luo, Wen; Zhao, Yong-mei; Tian, Run-guo; Su, Ya-bin; Hong, Chen

2013-11-01

A novel series of bis-nicotine derivatives (3a-3i) were designed, synthesized and evaluated as bivalent anti-Alzheimer's disease agents. The pharmacological results indicated that compounds 3e-3i inhibited both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in the micromolar range (IC50, 2.28-117.86 micromol x L(-1) for AChE and 1.67-125 micromol x L(-1) for BChE), which was at the same potency as rivastigmine. A Lineweaver-Burk plot and molecular modeling study showed that these derivatives targeted both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE. Besides, these compounds could significantly inhibit the self-induced Abeta aggregation with inhibition activity (11.85%-62.14%) at the concentration of 20 micromol x L(-1).

Effects of hyper- and hypothyroidism on acetylcholinesterase, (Na(+), K (+))- and Mg ( 2+ )-ATPase activities of adult rat hypothalamus and cerebellum.

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Carageorgiou, Haris; Pantos, Constantinos; Zarros, Apostolos; Stolakis, Vasileios; Mourouzis, Iordanis; Cokkinos, Dennis; Tsakiris, Stylianos

2007-03-01

Thyroid hormones (THs) are recognized as key metabolic hormones, and the metabolic rate increases in hyperthyroidism, while it decreases in hypothyroidism. The aim of this work was to investigate how changes in metabolism induced by THs could affect the activities of acetylcholinesterase (AChE), (Na(+), K(+))- and Mg(2+)-ATPase in the hypothalamus and the cerebellum of adult rats. Hyperthyroidism was induced by subcutaneous administration of thyroxine (25 microg/100 g body weight) once daily for 14 days, while hypothyroidism was induced by oral administration of propylthiouracil (0.05%) for 21 days. All enzyme activities were evaluated spectrophotometrically in the homogenated brain regions of 10 three-animal pools. Neither hyper-, nor hypothyroidism had any effect on the examined hypothalamic enzyme activities. In the cerebellum, hyperthyroidism provoked a significant decrease in both the AChE (-23%, p activities (-26%, p activities: AChE (-17%, p activity was found unaltered in both the hyper- and the hypothyroid brain regions. neither hyper-, nor hypothyroidism had any effect on the examined hypothalamic enzyme activities. In the cerebellum, hyperthyroidism provoked a significant decrease in both the AChE and the Na(+), K(+)-ATPase activities. The decreased (by the THs) Na(+), K(+)-ATPase activities may increase the synaptic acetylcholine release, and thus, could result in a decrease in the cerebellar AChE activity. Moreover, the above TH-induced changes may affect the monoamine neurotransmitter systems.

Analysis of structure and specific functional groups involved in acetylcholinesterase catalysis and inhibition. Final report, 14 June 1991-13 September 1994

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Taylor, P.

1994-10-01

The interactions of substrates, inhibitors and antibodies with Torpedo and mammalian acetylcholinesterases and butyrylcholinesterases have been studied by enzyme kinetic analyses, site-specific mutagenesis, molecular modeling, and peptide and antibody titrations. The high yield expression systems we developed have enabled us to obtain sufficient wild-type and mutant enzymes for the kinetic and physical studies. These studies have benefited from the availability of a three-dimensional X-ray-derived structure of acetylcholinesterase which allows for interpretations at an atomic level of resolution. Three distinct regions in the enzyme appear responsible for conferring selectivity: the acyl pocket defined primarily by phenylalanines 295 and 297, the choline subsite primarily defined by tryptophan 86, tyrosine 337 and glutamate 202 and the peripheral anionic site defined by tryptophan 286, tyrosine 72, tyrosine 124 and aspartate 74. Through site-specific mutagenesis we have been able to modify acyl pocket specificity, selectivity toward neutral and charged substrates, substrate inhibition, organophosphate reactivity, organophosphate aging and oxime reactivation. These studies have important implications in developing superior antidotes for organophosphate poisoning and in using recombinant acetylcholinesterase as an antidote.

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

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Létitia Jean

2007-07-01

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

Effect of Acetylcholinesterase and Butyrylcholinesterase on Intrauterine Insemination, Contribution to Inflammations, Oxidative Stress and Antioxidant Status; A Preliminary Report

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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 poxidative stress and inflammation and reduction in fertility rates by IUI. PMID:27478769

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

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

2014-05-07

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

Designing Second Generation Anti-Alzheimer Compounds as Inhibitors of Human Acetylcholinesterase: Computational Screening of Synthetic Molecules and Dietary Phytochemicals.

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Hafsa Amat-Ur-Rasool

Full Text Available Alzheimer's disease (AD, a big cause of memory loss, is a progressive neurodegenerative disorder. The disease leads to irreversible loss of neurons that result in reduced level of acetylcholine neurotransmitter (ACh. The reduction of ACh level impairs brain functioning. One aspect of AD therapy is to maintain ACh level up to a safe limit, by blocking acetylcholinesterase (AChE, an enzyme that is naturally responsible for its degradation. This research presents an in-silico screening and designing of hAChE inhibitors as potential anti-Alzheimer drugs. Molecular docking results of the database retrieved (synthetic chemicals and dietary phytochemicals and self-drawn ligands were compared with Food and Drug Administration (FDA approved drugs against AD as controls. Furthermore, computational ADME studies were performed on the hits to assess their safety. Human AChE was found to be most approptiate target site as compared to commonly used Torpedo AChE. Among the tested dietry phytochemicals, berberastine, berberine, yohimbine, sanguinarine, elemol and naringenin are the worth mentioning phytochemicals as potential anti-Alzheimer drugs The synthetic leads were mostly dual binding site inhibitors with two binding subunits linked by a carbon chain i.e. second generation AD drugs. Fifteen new heterodimers were designed that were computationally more efficient inhibitors than previously reported compounds. Using computational methods, compounds present in online chemical databases can be screened to design more efficient and safer drugs against cognitive symptoms of AD.

Designing Second Generation Anti-Alzheimer Compounds as Inhibitors of Human Acetylcholinesterase: Computational Screening of Synthetic Molecules and Dietary Phytochemicals.

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Amat-Ur-Rasool, Hafsa; Ahmed, Mehboob

2015-01-01

Alzheimer's disease (AD), a big cause of memory loss, is a progressive neurodegenerative disorder. The disease leads to irreversible loss of neurons that result in reduced level of acetylcholine neurotransmitter (ACh). The reduction of ACh level impairs brain functioning. One aspect of AD therapy is to maintain ACh level up to a safe limit, by blocking acetylcholinesterase (AChE), an enzyme that is naturally responsible for its degradation. This research presents an in-silico screening and designing of hAChE inhibitors as potential anti-Alzheimer drugs. Molecular docking results of the database retrieved (synthetic chemicals and dietary phytochemicals) and self-drawn ligands were compared with Food and Drug Administration (FDA) approved drugs against AD as controls. Furthermore, computational ADME studies were performed on the hits to assess their safety. Human AChE was found to be most approptiate target site as compared to commonly used Torpedo AChE. Among the tested dietry phytochemicals, berberastine, berberine, yohimbine, sanguinarine, elemol and naringenin are the worth mentioning phytochemicals as potential anti-Alzheimer drugs The synthetic leads were mostly dual binding site inhibitors with two binding subunits linked by a carbon chain i.e. second generation AD drugs. Fifteen new heterodimers were designed that were computationally more efficient inhibitors than previously reported compounds. Using computational methods, compounds present in online chemical databases can be screened to design more efficient and safer drugs against cognitive symptoms of AD.

Effects of chlorpyrifos on the transcription of CYP3A cDNA, activity of acetylcholinesterase, and oxidative stress response of goldfish (Carassius auratus).

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Ma, Junguo; Liu, Yang; Niu, Daichun; Li, Xiaoyu

2015-04-01

Chlorpyrifos (CPF) is the widely used organophosphate pesticide in agriculture throughout the world. It has been found that CPF is relatively safe to human but highly toxic to fish. In this study, acute toxicity of CPF on goldfish was determined and then the transcription of goldfish cytochrome P450 (CYP) 3A was evaluated after 96 h of CPF exposure at concentrations of 15.3 [1/10 50% lethal concentration (LC50 )] or 51 μg L(-1) (1/3 LC50 ) of CPF. Meanwhile, the enzymatic activities of acetylcholinesterase (AChE), superoxide dismutase (SOD), and catalase (CAT), total antioxidant activity (T-AOC), and the contents of malondialdehyde (MDA) in the liver or brain of goldfish were also determined. The results of acute toxicity testing showed that the 96-h LC50 of CPF to the goldfish was 153 μg L(-1) . Moreover, a length sequence of 1243 bp CYP3A cDNA encoding for 413 amino acids from goldfish liver was cloned. Polymerase chain reaction results reveal that CPF exposure downregulates CYP 3A transcription in goldfish liver, suggesting that goldfish CYP 3A may be not involved in CPF bioactivation. Finally, the results of biochemical assays indicate that 96 h of CPF exposure remarkably inhibits AChE activity in fish liver or brain, alters hepatic antioxidant enzyme activities, decreases brain T-AOC, and causes lipid peroxidation in fish liver. These results suggest that oxidative stress might be involved in CPF toxicity on goldfish. Copyright © 2013 Wiley Periodicals, Inc.

Colletotrichine B, a new sesquiterpenoid from Colletotrichum gloeosporioides GT-7, a fungal endophyte of Uncaria rhynchophylla.

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Chen, Xiao-Wei; Yang, Zhong-Duo; Li, Xiao-Fei; Sun, Jian-Hui; Yang, Li-Jun; Zhang, Xin-Guo

2018-02-08

One new compound, colletotrichine B (1), was produced by the fungal Colletotrichum gloeosporioides GT-7. The structure of 1 was elucidated on the basis of spectroscopic analysis and X-ray crystallographic analysis. Monoamine oxidase (MAO), acetylcholinesterase (AChE) and phosphoinositide 3-kinase (PI3Kα) inhibitory activity of 1 was also evaluated. Compound 1 showed only AChE inhibiting activity with IC 50 value of 38.0 ± 2.67 μg/mL.

Glutathione regulation-based dual-functional upconversion sensing-platform for acetylcholinesterase activity and cadmium ions.

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Fang, Aijin; Chen, Hongyu; Li, Haitao; Liu, Meiling; Zhang, Youyu; Yao, Shouzhuo

2017-01-15

A dual-functional platform for the sensing of acetylcholinesterase (AChE) activity and cadmium ions (Cd 2+ ) was developed based on the fluorescence resonance energy transfer (FRET) between NaYF 4 :Yb,Er upconversion nanoparticles (UCNPs) and gold nanoparticles (AuNPs) via glutathione regulation. The detection mechanism is based on the fact that AuNPs can quench the fluorescence of UCNPs. AChE catalyzes the hydrolysis of acetylthiocholine (ATC) into thiocholine which reacts with AuNPs by S-Au conjunction and results the aggregation of AuNPs and change in fluorescence of UCNPs. Therefore, the AChE activity can be detected through the changes of the color of solution and fluorescence recovery of UCNPs. However, the presence of glutathione (GSH) can protect AuNPs from aggregation and enlarge the inter-particle distance between AuNPs and UCNPs. When Cd 2+ is added into the stable mixture of AuNPs, GSH and AChE/ATC, Cd 2+ could interact with GSH to form a spherical shaped (GSH) 4 Cd complex, which decreases the free GSH on the surface of AuNPs to weaken the stability of AuNPs and lead to the easily aggregation of them in the system. The aggregated-AuNPs are released from the surface of UCNPs, which results in the fluorescence of UCNPs gradually recovered. Under the optimized conditions, the detection limits of AChE activity and Cd 2+ are estimated to be 0.015mU/mL and 0.2µM, respectively. The small molecules regulated dual-functional platform based on UCNPs/AuNPs is a simple, label-free method and can be applied for the turn-on fluorescence detection of AChE activity in human serum and Cd 2+ in real water samples. The present work demonstrates a general strategy for the design of small molecules regulated multifunctional platform and will be expanded for different areas in the future. Copyright © 2016 Elsevier B.V. All rights reserved.

New pyridine derivatives as inhibitors of acetylcholinesterase and amyloid aggregation.

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Pandolfi, Fabiana; De Vita, Daniela; Bortolami, Martina; Coluccia, Antonio; Di Santo, Roberto; Costi, Roberta; Andrisano, Vincenza; Alabiso, Francesco; Bergamini, Christian; Fato, Romana; Bartolini, Manuela; Scipione, Luigi

2017-12-01

A new series of pyridine derivatives with carbamic or amidic function has been designed and synthesized to act as cholinesterase inhibitors. The synthesized compounds were tested toward EeAChE and hAChE and toward eqBChE and hBChE. The carbamate 8 was the most potent hAChE inhibitor (IC 50  = 0.153 ± 0.016 μM) while the carbamate 11 was the most potent inhibitor of hBChE (IC 50  = 0.828 ± 0.067 μM). A molecular docking study indicated that the carbamate 8 was able to bind AChE by interacting with both CAS and PAS, in agreement with the mixed inhibition mechanism. Furthermore, the carbamates 8, 9 and 11 were able to inhibit Aβ 42 self-aggregation and possessed quite low toxicity against human astrocytoma T67 and HeLa cell lines, being the carbamate 8 the less toxic compound on both cell lines. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Production and enzyme engineerinq of human acetylcholinesterase and its mutant derivatives. Midterm report, 15 January 1993-15 July 1994

Energy Technology Data Exchange (ETDEWEB)

Shafferman, A.

1994-07-15

Specificity determinants of human acetylcholinesterase (HuAChE) towards ligands (substrate and some reversible and irreversible inhibitors) were identified by combination of site-directed mutagenesis, molecular modeling and kinetic studies with enzymes mutated in active center residues Trp86, Glu202, Trp286, Phe295, Phe297, Tyr337, Phe338 and Glu450. Thus, the anionic and hydrophobic subsites as well as the acyl pocket were identified. Enzymes with resistance to OP aging were engineered.The role of N-glycosylation in the function, biosynthesis and stability of HuAChE was examined by site-directed mutagenesis (Asn to GIn substitution) of the three potential N glycosylation sites, Asn265, Asn350 and Asn464. Large scale preparation of recombinant HuAChE was performed utilizing the microcarrier technology. Over 500 milligrams of enzyme was prepared for x-ray crystallography.

Antimicrobial and acetylcholinesterase inhibitory activities of Buddleja salviifolia (L.) Lam. leaf extracts and isolated compounds.

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Pendota, S C; Aderogba, M A; Ndhlala, A R; Van Staden, J

2013-07-09

Buddleja salviifolia leaves are used for the treatment of eye infections and neurodegenerative conditions by various tribes in South Africa. This study was designed to isolate the phenolic constituents from the leaf extracts of Buddleja salviifolia and evaluate their antimicrobial and acetylcholinesterase (AChE) activities. Three phenolic compounds were isolated from the ethyl acetate fraction of a 20% aqueous methanol leaf extract of Buddleja salviifolia using Sephadex LH-20 and silica gel columns. Structure elucidation of the isolated compounds was carried out using spectroscopic techniques: mass spectrometry (ESI-TOF-MS) and NMR (1D and 2D). The extracts and isolated compounds were evaluated for antimicrobial and acetylcholinesterase activities using the microdilution technique. The bacteria used for the antimicrobial assays were Gram-positive Bacillus subtilis and Staphylococcus aureus and Gram-negative Escherichia coli and Klebsiella pneumoniae. The isolated compounds were characterized as: 4'-hydroxyphenyl ethyl vanillate (1) a new natural product, acteoside (2) and quercetin (3). The crude extract, fractions and the isolated compounds from the leaves of the plant exhibited a broad spectrum of antibacterial activity. The EtOAc fraction exhibited good activity against Bacillus subtilis and Staphylococcus aureus with MIC values ranging from 780.0 to 390.0 µg/mL. Isolated compound 2 exhibited good activity against Staphylococcus aureus with an MIC value of 62.5 µg/mL. The hexane and DCM fractions of leaves showed the best activity against Candida albicans with MIC and MFC values of 390.0 µg/mL. In the AChE inhibitory test, among the tested extracts, the hexane fraction was the most potent with an IC50 value of 107.4 µg/mL, whereas for the isolated compounds, it was compound (3) (quercetin) with an IC50 value of 66.8 µg/mL. Activities demonstrated by the extracts and isolated compounds support the ethnopharmacological use of Buddleja salviifolia against eye

Physiological Responses in Chinese Rare Minnow Larvae Following Exposure to Low-Dose Tributyltin.

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Li, Ping; Li, Zhi-Hua

2015-11-01

In the present study, the antioxidant response and acetylcholinesterase (AChE) activity were measured in Chinese rare minnow larvae (Gobiocypris rarus) after exposure to tributyltin (TBT) (0, 100, 400 and 800 ngL(-1)) for 7 days, as well as the expression of a series of genes, including cr, aptase and prl genes involved in the ion-regulatory process and igfbp3 and gh related to growth rate. Results shows that oxidative stress was generated in fish exposed to TBT, as evidenced by elevated malondialdehyde levels and the inhibition of antioxidant parameters. The activity of acetylcholinesterase (AChE) was also inhibited in fish under higher TBT stress. Moreover, genes involved in ion regulation and growth were affected, based on the regulated transcription of the cr, atpase, gh, prl and igfbp3 genes in the treated groups. The observed effects of TBT upon antioxidant responses and altered expression of genes provides insight into the use of these molecular biomarkers in evaluating mechanisms of TBT toxicity in fish.

A review on cholinesterase inhibitors for Alzheimer's disease.

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Anand, Preet; Singh, Baldev

2013-04-01

Alzheimer's disease (AD), a progressive neurodegenerative disorder, is characterized by the deficits in the cholinergic system and deposition of beta amyloid (Aβ) in the form of neurofibrillary tangles and amyloid plaques. Since the cholinergic system plays an important role in the regulation of learning and memory processes, it has been targetted for the design of anti-Alzheimer's drugs. Cholinesterase inhibitors enhance cholinergic transmission directly by inhibiting the enzyme acetylcholinesterase (AChE) which hydrolyses acetylcholine. Furthermore, it has been also demonstrated that both acetylcholinesterase and butrylcholinesterase (BuChE) play an important role in Aβ-aggregation during the early stages of senile plaque formation. Therefore, AChE and BuChE inhibition have been documented as critical targets for the effective management of AD by an increase in the availability of acetylcholine in the brain regions and decrease in the Aβ deposition. This review discusses the different classes of cholinesterase inhibitors including tacrine, donepezil, rivastigmine, galantamine, xanthostigmine, para-aminobenzoic acid, coumarin, flavonoid, and pyrrolo-isoxazole analogues developed for the treatment of AD.

Arctigenin isolated from the seeds of Arctium lappa ameliorates memory deficits in mice.

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Lee, In-Ah; Joh, Eun-Ha; Kim, Dong-Hyun

2011-09-01

The seeds of Arctium lappa L. (AL, family Asteraceae), the main constituents of which are arctiin and arctigenin, have been used as an herbal medicine or functional food to treat inflammatory diseases. These main constituents were shown to inhibit acetylcholinesterase (AChE) activity. Arctigenin more potently inhibited AChE activity than arctiin. Arctigenin at doses of 30 and 60 mg/kg (p. o.) potently reversed scopolamine-induced memory deficits by 62 % and 73 %, respectively, in a passive avoidance test. This finding is comparable with that of tacrine (10 mg/kg p. o.). Arctigenin also significantly reversed scopolamine-induced memory deficits in the Y-maze and Morris water maze tests. On the basis of these findings, arctigenin may ameliorate memory deficits by inhibiting AChE. © Georg Thieme Verlag KG Stuttgart · New York.

A highly stable acetylcholinesterase biosensor based on chitosan-TiO2-graphene nanocomposites for detection of organophosphate pesticides.

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Cui, Hui-Fang; Wu, Wen-Wen; Li, Meng-Meng; Song, Xiaojie; Lv, Yuanxu; Zhang, Ting-Ting

2018-01-15

A highly stable electrochemical acetylcholinesterase (AChE) biosensor for detection of organophosphorus pesticides (OPs) was developed simply by adsorption of AChE on chitosan (CS), TiO 2 sol-gel, and reduced graphene oxide (rGO) based multi-layered immobilization matrix (denoted as CS @ TiO 2 -CS/rGO). The biosensor fabrication conditions were optimized, and the fabrication process was probed and confirmed by scanning electron microscopy and electrochemical techniques. The matrix has a mesoporous nanostructure. Incorporation of CS and electrodeposition of a CS layer into/on the TiO 2 sol-gel makes the gel become mechanically strong. The catalytic activity of the AChE immobilized CS @ TiO 2 -CS/rGO/glassy carbon electrode to acetylthiocholine is significantly higher than those missing any one of the component in the matrix. The detection linear range of the biosensor to dichlorvos, a model OP compound, is from 0.036μM (7.9 ppb) to 22.6μM, with a limit of detection of 29nM (6.4 ppb) and a total detection time of about 25min. The biosensor is very reproducibly and stable both in detection and in storage, and can accurately detect the dichlorvos levels in cabbage juice samples, providing an efficient platform for immobilization of AChE, and a promisingly applicable OPs biosensor with high reliability, simplicity, and rapidness. Copyright © 2017 Elsevier B.V. All rights reserved.

Coumarin derivatives bearing benzoheterocycle moiety: synthesis, cholinesterase inhibitory, and docking simulation study

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Kimia Hirbod

2017-06-01

Full Text Available Objective(s: To investigate the efficiency of a novel series of coumarin derivatives bearing benzoheterocycle moiety as novel cholinesterase inhibitors. Materials and Methods: Different 7-hydroxycoumarin derivatives were synthesized via Pechmann or Knoevenagel condensation and conjugated to different benzoheterocycle (8-hydroxyquinoline, 2-mercaptobenzoxazole or 2-mercaptobenzimidazole using dibromoalkanes 3a-m. Final compounds were evaluated against acetylcholinesterase (AChE and butyrylcholinesterase (BuChE by Ellman's method. Kinetic study of AChE inhibition and ligand-protein docking simulation were also carried out for the most potent compound 3b. Results: Some of the compounds revealed potent and selective activity against AChE. Compound 3b containing the quinoline group showed the best activity with an IC50 value of 8.80 µM against AChE. Kinetic study of AChE inhibition revealed the mixed-type inhibition of the enzyme by compound 3b. Ligand-protein docking simulation also showed that the flexibility of the hydrophobic five carbons linker allows the quinoline ring to form π-π interaction with Trp279 in the PAS. Conclusion: We suggest these synthesized compounds could become potential leads for AChE inhibition and prevention of AD symptoms.

Cholinesterase inhibitory activity and structure elucidation of a new phytol derivative and a new cinnamic acid ester from Pycnanthus angolensis

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Taiwo O. Elufioye

Full Text Available ABSTRACT The leaves of Pycnanthus angolensis (Welw. Warb., Myristicaceae, are used as memory enhancer and anti-ageing in Nigerian ethnomedicine. This study aimed at evaluating the cholinesterase inhibitory property as well as isolates the bioactive compounds from the plant. The acetylcholinesterase and butyrylcholinesterase inhibitory potentials of extracts, fractions, and isolated compounds were evaluated by colorimetric and TLC bioautographic assay techniques. The extract inhibited both enzymes with activity increasing with purification, ethyl acetate fraction being most active fraction at 65.66 ± 1.06% and 49.38 ± 1.66% against acetylcholinesterase and butyrylcholinesterase, respectively while the supernatant had 77.44 ± 1.18 inhibition against acetylcholinesterase. Two new bioactive compounds, (2E, 18E-3,7,11,15,18-pentamethylhenicosa-2,18-dien-1-ol (named eluptol and [12-(4-hydroxy-3-methyl-oxo-cyclopenta-1,3-dien-1yl-11-methyl-dodecyl](E-3-(3,4-dimethylphenylprop-2-enoate (named omifoate A were isolated from the plant with IC50 of 22.26 µg/ml (AChE, 34.61 µg/ml (BuChE and 6.51 µg/ml (AChE, 9.07 µg/ml (BuChE respectively. The results showed that the plant has cholinesterase inhibitory activity which might be responsible for its memory enhancing action, thus justifying its inclusion in traditional memory enhancing preparations

How does huperzine A enter and leave the binding gorge of acetylcholinesterase? Steered molecular dynamics simulations.

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Xu, Yechun; Shen, Jianhua; Luo, Xiaomin; Silman, Israel; Sussman, Joel L; Chen, Kaixian; Jiang, Hualiang

2003-09-17

The entering and leaving processes of Huperzine A (HupA) binding with the long active-site gorge of Torpedo californica acetylcholinesterase (TcAChE) have been investigated by using steered molecular dynamics simulations. The analysis of the force required along the pathway shows that it is easier for HupA to bind to the active site of AChE than to disassociate from it, which for the first time interprets at the atomic level the previous experimental result that unbinding process of HupA is much slower than its binding process to AChE. The direct hydrogen bonds, water bridges, and hydrophobic interactions were analyzed during two steered molecular dynamics (SMD) simulations. Break of the direct hydrogen bond needs a great pulling force. The steric hindrance of bottleneck might be the most important factor to produce the maximal rupture force for HupA to leave the binding site but it has a little effect on the binding process of HupA with AChE. Residue Asp72 forms a lot of water bridges with HupA leaving and entering the AChE binding gorge, acting as a clamp to take out HupA from or put HupA into the active site. The flip of the peptide bond between Gly117 and Gly118 has been detected during both the conventional MD and SMD simulations. The simulation results indicate that this flip phenomenon could be an intrinsic property of AChE and the Gly117-Gly118 peptide bond in both HupA bound and unbound AChE structures tends to adopt the native enzyme structure. At last, in a vacuum the rupture force is increased up to 1500 pN while in water solution the greatest rupture force is about 800 pN, which means water molecules in the binding gorge act as lubricant to facilitate HupA entering or leaving the binding gorge.

Structure of HI-6*sarin-acetylcholinesterase determined by X-ray crystallography and molecular dynamics simulation: reactivator mechanism and design.

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Fredrik Ekström

2009-06-01

Full Text Available Organophosphonates such as isopropyl metylphosphonofluoridate (sarin are extremely toxic as they phosphonylate the catalytic serine residue of acetylcholinesterase (AChE, an enzyme essential to humans and other species. Design of effective AChE reactivators as antidotes to various organophosphonates requires information on how the reactivators interact with the phosphonylated AChEs. However, such information has not been available hitherto because of three main challenges. First, reactivators are generally flexible in order to change from the ground state to the transition state for reactivation; this flexibility discourages determination of crystal structures of AChE in complex with effective reactivators that are intrinsically disordered. Second, reactivation occurs upon binding of a reactivator to the phosphonylated AChE. Third, the phosphorous conjugate can develop resistance to reactivation. We have identified crystallographic conditions that led to the determination of a crystal structure of the sarin(nonaged-conjugated mouse AChE in complex with [(E-[1-[(4-carbamoylpyridin-1-ium-1-ylmethoxymethyl]pyridin-2-ylidene]methyl]-oxoazanium dichloride (HI-6 at a resolution of 2.2 A. In this structure, the carboxyamino-pyridinium ring of HI-6 is sandwiched by Tyr124 and Trp286, however, the oxime-pyridinium ring is disordered. By combining crystallography with microsecond molecular dynamics simulation, we determined the oxime-pyridinium ring structure, which shows that the oxime group of HI-6 can form a hydrogen-bond network to the sarin isopropyl ether oxygen, and a water molecule is able to form a hydrogen bond to the catalytic histidine residue and subsequently deprotonates the oxime for reactivation. These results offer insights into the reactivation mechanism of HI-6 and design of better reactivators.

The stability of AQT processing speed, ADAS-Cog and MMSE during acetylcholinesterase inhibitor treatment in Alzheimer's disease.

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Wiig, E H; Annas, P; Basun, H; Andreasen, N; Lannfelt, L; Zetterberg, H; Blennow, K; Minthon, L

2010-03-01

To explore the longitudinal stability of measures of cognition during treatment with acetylcholinesterase inhibitors (AchEI) in patients with Alzheimer's disease (AD). Cognitive status was measured in a cohort of 60 patients at 6 months after initiation of treatment with AchEI (baseline) and after an additional 6 months of treatment (endpoint). A Quick Test of Cognitive Speed (AQT), Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog), and MMSE were administered concurrently. Correlations (rho) between age and AQT processing speed were non-significant, but were significant for ADAS-Cog and Mini Mental State Examination (MMSE). AQT and ADAS-Cog means did not differ significantly between baseline and endpoint. There was a small, significant reduction in MMSE point scores. Measures of stability (Spearman's rho) were moderate-to-high for all tests. Means for subgroups did not differ as a function of medication type. AQT processing speed, ADAS-Cog, and MMSE measures proved stable during the second 6 months of treatment with AChEI.

Effect of adult onset hypothyroidism on behavioral parameters and acetylcholinesterase isoforms activity in specific brain regions of male mice.

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Vasilopoulou, Catherine G; Constantinou, Caterina; Giannakopoulou, Dimitra; Giompres, Panagiotis; Margarity, Marigoula

2016-10-01

Thyroid hormones (TH) are essential for normal development and function of mammalian central nervous system (CNS); TH dysregulation has been implicated in several cognitive and behavioral deficits related to dysfunctions of neurotransmitter systems. In the present study, we investigated the effects of adult onset hypothyroidism on the activity of acetylcholinesterase (AChE) and on related behavioral parameters. For this purpose we used adult male Balb/cJ mice that were divided randomly into euthyroid and hypothyroid animal groups. Animals were rendered hypothyroid through administration of 1% w/v KClO4 in their drinking water for 8weeks. At the end of the treatment, learning/memory procedures were examined through step-through passive avoidance task while fear/anxiety was assessed using elevated plus-maze (EPM) and open-field (OF) tests. AChE activity was determined colorimetrically in two different fractions, salt-soluble fraction (SS) (containing mainly the G1 isoform) and detergent-soluble fraction (DS) (containing mainly the G4 isoform) in cerebral cortex, cerebellum, midbrain, hippocampus and striatum. Our results indicate that adult onset hypothyroidism caused significant memory impairment and increased fear/anxiety. Moreover, the activity of both isoforms of AChE was reduced in all brain regions examined in a brain region- and isoform-specific manner. Copyright © 2016. Published by Elsevier Inc.

Phytochemical Constituents, ChEs and Urease Inhibitions, Antiproliferative and Antioxidant Properties of Elaeagnus umbellata Thunb.

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Ozen, Tevfik; Yenigun, Semiha; Altun, Muhammed; Demirtas, Ibrahim

2017-01-01

Due to the common ethnopharmacological used or scientifically examined biochemical properties, Elaeagnaceae family, Elaeagnus umbellate (Thunb.) (EU, Guz yemisi) was worth investigating. In this investigation, we revealed antioxidant, antiproliferative and enzyme inhibition activities of the water, methanol, ethanol, acetone, ethyl acetate and hexane extracts of EU as well as the contents of their phenolic, flavonoid, anthocyanin, ascorbic acid, lycopene and β- carotene. The antioxidant activity was screened by total antioxidant (phosphomolybdenum), inhibition of linoleic acid peroxidation, reducing power, 2-deoxyribose degradation assay, H2O2 scavenging and metal chelating activities of the samples were tested in vitro. Additionally, the scavenging activities of the extracts were determined against 1,1-diphenyl-2-picrylhydrazyl (DPPH˙), 2,2-azino-bis(3-ethylbenzothiazloine-6-sulfonicacid (ABTS˙+), superoxide anion and peroxide radicals. The samples were determined for their inhibitory activities against urease, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). In vitro, antiproliferative activities of six different extracts were tested using the xCELLigence system against HeLa and HT29 cell lines. The antioxidant activities of the extracts were found higher than standard antioxidants. The water extracts of fruit and leaf showed the best antioxidant activity. In inhibition assays of urease, AChE and BuChE, all extracts exhibited remarkable inhibition potential. Ethyl acetate extracts, especially, showed better inhibition capacity. It was found that the antioxidant activities of the extracts presented consistently with their chemical contents. The antiproliferative activities of leaf extracts were more effective than the fruit extracts. The chromatographic methods were applied to the different solvents to analyses phenolic secondery metabolites. It was found that fumaric acid, 4- hydroxybenzoic acid, rutin and quercetin-3-�

Point mutations in acetylcholinesterase 1 associated with chlorpyrifos resistance in the brown planthopper, Nilaparvata lugens Stål.

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Zhang, Y; Yang, B; Li, J; Liu, M; Liu, Z

2017-08-01

Insecticide resistance frequently results from target-site insensitivity, such as point mutations in acetylcholinesterases (AChEs) for resistance to organophosphates and carbamates. From a field-originated population of Nilaparvata lugens, a major rice pest, a resistant population (R9) was obtained by nine-generation continuous selection with chlorpyrifos. From the same field population, a relatively susceptible population (S9) was also constructed through rearing without any insecticides. Compared to the susceptible strain, Sus [medium lethal dose (LC 50 ) = 0.012 mg/l], R9 had a resistance ratio (RR) of 253.08-fold, whereas the RR of S9 was only 2.25-fold. Piperonyl butoxide and triphenyl phosphate synergized chlorpyrifos in R9 less than three-fold, indicating other important mechanisms for high resistance. The target-site insensitivity was supported by the key property differences of crude AChEs between R9 and S9. Compared to S9, three mutations (G119S, F331C and I332L) were detected in NlAChE1 from individuals of the R9 and field populations, but no mutation was detected in NlAChE2. G119S and F331C could decreased insecticide sensitivities in recombinant NlAChE1, whereas I332L took effect through increasing the influence of F331C on target insensitivity. F331C might be deleterious because of its influence on the catalytic efficiency of NlAChE1, whereas I332L would decrease these adverse effects and maintain the normal functions of AChEs. © 2017 The Royal Entomological Society.

Optogenetic release of ACh induces rhythmic bursts of perisomatic IPSCs in hippocampus.

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Daniel A Nagode

Full Text Available Acetylcholine (ACh influences a vast array of phenomena in cortical systems. It alters many ionic conductances and neuronal firing behavior, often by regulating membrane potential oscillations in populations of cells. Synaptic inhibition has crucial roles in many forms of oscillation, and cholinergic mechanisms regulate both oscillations and synaptic inhibition. In vitro investigations using bath-application of cholinergic receptor agonists, or bulk tissue electrical stimulation to release endogenous ACh, have led to insights into cholinergic function, but questions remain because of the relative lack of selectivity of these forms of stimulation. To investigate the effects of selective release of ACh on interneurons and oscillations, we used an optogenetic approach in which the light-sensitive non-selective cation channel, Channelrhodopsin2 (ChR2, was virally delivered to cholinergic projection neurons in the medial septum/diagonal band of Broca (MS/DBB of adult mice expressing Cre-recombinase under the control of the choline-acetyltransferase (ChAT promoter. Acute hippocampal slices obtained from these animals weeks later revealed ChR2 expression in cholinergic axons. Brief trains of blue light pulses delivered to untreated slices initiated bursts of ACh-evoked, inhibitory post-synaptic currents (L-IPSCs in CA1 pyramidal cells that lasted for 10's of seconds after the light stimulation ceased. L-IPSC occurred more reliably in slices treated with eserine and a very low concentration of 4-AP, which were therefore used in most experiments. The rhythmic, L-IPSCs were driven primarily by muscarinic ACh receptors (mAChRs, and could be suppressed by endocannabinoid release from pyramidal cells. Finally, low-frequency oscillations (LFOs of local field potentials (LFPs were significantly cross-correlated with the L-IPSCs, and reversal of the LFPs near s. pyramidale confirmed that the LFPs were driven by perisomatic inhibition. This optogenetic approach

Bienzymatic Acetylcholinesterase and Choline Oxidase Immobilized Biosensor Based on a Phenyl Carboxylic Acid-Grafted Multiwalled Carbon Nanotube

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So-Ra Lee

2014-01-01

Full Text Available Bienzymatic acetylcholinesterase (AChE and choline oxidase (ChOx immobilized biosensor based on a phenyl carboxylic acid-grafted multiwalled carbon nanotube (MWNT modified glass carbon electrode (GCE and carbon-screen printed electrode (SPE was fabricated for acetylcholine detection in human blood samples. Phenyl carboxylic acid-modified MWNT supports were prepared by electrochemical polymerization of 4-carboxyphenyl diazonium salts, which were synthesized by an amine group and sodium nitrite, on the surface of the MWNT-modified GCE and SPE in 0.1 M PBS. The successful fabrication of the AChE-ChOx-immobilized biosensor was confirmed via scanning electron microscopy (SEM, X-ray photoelectron spectroscopy (XPS, electrochemical impedance spectroscopy (EIS, and cyclic voltammetry (CV. The sensing range of the biosensor based on a GCE and SPE was 1.0~10 μM and 10~100 μM, respectively. The interfering effect of 0.1 M L-ascorbic acid, 0.1 M L-cysteine, and 0.1 M uric acid to 0.1 M acetylcholine was 3.00%, 9.00%, and 3.00%, respectively. Acetylcholine in a human blood sample was detected by the AChE-ChOx-immobilized biosensor.

In Vitro Restoration of an Amyloid-Beta Altered Network Circuitry in a 'Mutated Biomimetic Acetylcholinesterase' Memristor/Memcapacitor Neural Prosthesis

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John THORNTON

2015-08-01

Full Text Available Many diseases involve the ysregulation of acetylcholinesterase (ACHE causing inappropriate production of the neurotransmitter acetylcholine (ACH. Study of how the ACH actually restores a life threatening neural circuitry damage will provide valuable information for study Alzhermer’s disease. An artificial neuronal device was developed with nanostructured biomimetic mutated ACHE gorge membrane on gold chips having memristor/memcapacitor’s characteristics, served as a model for damaged brain circuitry prosthesis, compared before and after ACH treatments, for in vitro evaluation of the memory restoration in the presence of Amyloid-beta (Ab under the conditions of free from tracers and antibodies in NIST human serum. The results are presented in three categories in “Energy-Sensory” images. Before ACH treatments, images showed four stages of circuitry damages from non symptomatic to life threatening. After a 15 nM ACH treatment, the circuitry was restored due to the ACH removed Pathological High Frequency Oscillation (pHFO center during Slow- Waving Sleeping (SWS. After the prosthesis increased hydrophobicity, the High Frequency Oscillation (HFO was created. Results were compared between the recovered and the “normal brain”: 0.14 vs. 0.47 pJ/bit/µm3 for long-term and 14.0 vs.7.0 aJ/bit/µm3 for short-term memory restoration, respectively. The ratio of Rmax/Rmin value is 6.3-fold higher after the treatment of ACH compared without the treatment in the presence of Ab and the reentry sensitivity increased by 613.8- fold.

Determination of malation, methidathion, and chlorpyrifos ethyl pesticides using acetylcholinesterase biosensor based on Nafion/Ag@rGO-NH_2 nanocomposites

International Nuclear Information System (INIS)

Guler, Muhammet; Turkoglu, Vedat; Basi, Zehra

2017-01-01

Herein, a facile electrochemical acetylcholinesterase (EC 3.1.1.7; AChE) biosensor based on nafion (NA) and Ag nanoparticles supported on amine functionalized reduced graphene oxide (rGO-NH_2) was developed. The Ag@rGO-NH_2 nanocomposite was characterized using Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). After being optimized, the biosensor exhibited excellent electrochemical response to the oxidation of thiocholine, the hydrolysis product of acetylthiocholine chloride (ATCl) catalyzed by AChE. An apparent Michealis-Menten value of 20.5 μM was obtained. Under optimized conductions, the biosensor detected malation, methidathion, and chlorpyrifos ethyl in the linear range from 0.0063 to 0.077 μg/mL, from 0.012 to 0.105 μg/mL, and from 0.021 to 0.122 μg/mL, respectively. The detection limit (LoD) was 4.5 ng/mL for malation, 9.5 ng/mL for methidathion, and 14 ng/mL for chlorpyrifos ethyl. Also, the NA/Ag@rGO-NH_2/AChE/GCE biosensor showed god sensitivity, stability and repeatability, which provides a promising tool for the detection of organophosphate pesticides.

Development of Cholinesterase Inhibitors Using (a)-Lipoic Acid-benzyl Piperazine Hybrid Molecules

International Nuclear Information System (INIS)

Kim, Beomcheol; Lee, Seunghwan; Jang, Mi; Shon, Min Young; Park, Jeong Ho

2013-01-01

A series of hybrid molecules between (α)-lipoic acid (ALA) and benzyl piperazines were synthesized and their in vitro cholinesterase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)] inhibitory activities were evaluated. Even though the parent compounds did not show any inhibitory activity against cholinesterase (ChE), all hybrid molecules showed BuChE inhibitory activity. Some hybrid compounds also displayed AChE inhibitory activity. Specifically, ALA-1-(3-methylbenzyl)piperazine (15) was shown to be an effective inhibitor of both BuChE (IC 50 = 2.3 ± 0.7 μM) and AChE (IC 50 = 30.31 ± 0.64 μM). An inhibition kinetic study using compound 15 indicated a mixed inhibition type. Its binding affinity (K i ) value to BuChE is 2.91 ± 0.15 μM

Acetylcholinesterase inhibition and antioxidant activity of essential oils from Schinus areira L. and Schinus longifolia (Lindl.) Speg.

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Murray, Ana P; Gurovic, Maria S Vela; Rodriguez, Silvana A; Murray, María G; Ferrero, Adriana A

2009-06-01

The essential oils of Schinus areira L. and S. longifolia (Lindl.) Speg. (Anacardiaceae) have been studied for their in vitro anti-acetylcholinesterase and antioxidant activities. The chemical composition of the oils obtained by hydrodistillation was determined by GC-MS. Fruit and leaf oils of S. areira were analyzed separately. The essential oil from S. longifolia elicited marked enzymatic inhibition (IC50 = 20.0 +/- 1.0 microg/mL) and showed radical scavenger activity (IC50 = 25.2 +/- 2.4 microg/mL). The essential oil from S. areira leaves was more active than that of the fruits in both bioassays.

Evidence for cholinergic participation in the control of bird song; acetylcholinesterase distribution and muscarinic receptor autoradiography in the zebra finch brain

International Nuclear Information System (INIS)

Ryan, S.M.; Arnold, A.P.

1981-01-01

Brain regions thought to be involved in the control of song in the zebra finch (Poephila guttata), were examined histochemically using the Karnovsky and Roots direct-coloring method for the detection of acetylcholinesterase (AChE) and the autoradiographic method for the localization of muscarinic cholinergic receptors following injection of tritiated quinuclidinyl benzilate (3H QNB). All presently identified vocal control nuclei in both males and females contain AChE. These nuclei include Area X, magnocellular nucleus of the anterior neostriatum (MAN), nucleus interface (NIF), caudal nucleus of the hyperstriatum ventrale (HVc), intercollicular nucleus (ICo), nucleus uva, robust nucleus of the archistriatum (RA), and tracheosyringeal portion of the hypoglossal nerve nucleus (nXIIts). All nuclei except Area X contain mostly AChE-synthesizing cell bodies. All of these nuclei contain some AChE in the neuropil, with particularly intense staining in Area X, the surrounding LPO, and the dorsomedial portion of ICo. In agreement with this description are very high concentrations of 3H QNB in both Area X and the dorsomedial ICo. HVc also appears specifically labeled. Evidence from these two histological technique suggests that efferent projections of most vocal control area may utilize acetylcholine, and that several of the vocal control nuclei may themselves receive muscarinic cholinergic projection. In Area X, there are sex differences of AChE neuropil staining. This evidence suggesting that sexually dimorphic projections to or within Area X are cholinergic or cholinoceptive

Analogous β-Carboline Alkaloids Harmaline and Harmine Ameliorate Scopolamine-Induced Cognition Dysfunction by Attenuating Acetylcholinesterase Activity, Oxidative Stress, and Inflammation in Mice

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Li, Shu-Ping; Wang, Yu-Wen; Qi, Sheng-Lan; Zhang, Yun-Peng; Deng, Gang; Ding, Wen-Zheng; Ma, Chao; Lin, Qi-Yan; Guan, Hui-Da; Liu, Wei; Cheng, Xue-Mei; Wang, Chang-Hong

2018-01-01

The analogous β-carboline alkaloids, harmaline (HAL) and harmine (HAR), possess a variety of biological properties, including acetylcholinesterase (AChE) inhibitory activity, antioxidant, anti-inflammatory, and many others, and have great potential for treating Alzheimer’s disease (AD). However, studies have showed that the two compounds have similar structures and in vitro AChE inhibitory activities but with significant difference in bioavailability. The objective of this study was to comparatively investigate the effects of HAL and HAR in memory deficits of scopolamine-induced mice. In the present study, mice were pretreated with HAL (2, 5, and 10 mg/kg), HAR (10, 20, and 30 mg/kg) and donepezil (5 mg/kg) by intragastrically for 7 days, and were daily intraperitoneal injected with scopolamine (1 mg/kg) to induce memory deficits and then subjected to behavioral evaluation by Morris water maze. To further elucidate the underlying mechanisms of HAL and HAR in improving learning and memory, the levels of various biochemical factors and protein expressions related to cholinergic function, oxidative stress, and inflammation were examined. The results showed that HAL and HAR could effectively ameliorate memory deficits in scopolamine-induced mice. Both of them exhibited an enhancement in cholinergic function by inhibiting AChE and inducing choline acetyltransferase (ChAT) activities, and antioxidant defense via increasing the antioxidant enzymes activities of superoxide dismutase and glutathione peroxidase, and reducing maleic diadehyde production, and anti-inflammatory effects through suppressing myeloperoxidase, tumor necrosis factor α, and nitric oxide as well as modulation of critical neurotransmitters such as acetylcholine (ACh), choline (Ch), L-tryptophan (L-Trp), 5-hydroxytryptamine (5-HT), γ-aminobutyric acid (γ-GABA), and L-glutamic acid (L-Glu). Furthermore, the regulations of HAL on cholinergic function, inflammation, and neurotransmitters were more

Anti-acetylcholinesterase activity and antioxidant properties of extracts and fractions of Carpolobia lutea.

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Nwidu, Lucky Legbosi; Elmorsy, Ekramy; Thornton, Jack; Wijamunige, Buddhika; Wijesekara, Anusha; Tarbox, Rebecca; Warren, Averil; Carter, Wayne Grant

2017-12-01

There is an unmet need to discover new treatments for Alzheimer's disease. This study determined the anti-acetylcholinesterase (AChE) activity, DPPH free radical scavenging and antioxidant properties of Carpolobia lutea G. Don (Polygalaceae). The objective of this study is to quantify C. lutea anti-AChE, DPPH free radical scavenging, and antioxidant activities and cell cytotoxicity. Plant stem, leaves and roots were subjected to sequential solvent extractions, and screened for anti-AChE activity across a concentration range of 0.02-200 μg/mL. Plant DPPH radical scavenging activity, reducing power, and total phenolic and flavonoid contents were determined, and cytotoxicity evaluated using human hepatocytes. Carpolobia lutea exhibited concentration-dependent anti-AChE activity. The most potent inhibitory activity for the stem was the crude ethanol extract and hexane stem fraction oil (IC 50  = 140 μg/mL); for the leaves, the chloroform leaf fraction (IC 50  = 60 μg/mL); and for roots, the methanol, ethyl acetate and aqueous root fractions (IC 50  = 0.3-3 μg/mL). Dose-dependent free radical scavenging activity and reducing power were observed with increasing stem, leaf or root concentration. Total phenolic contents were the highest in the stem: ∼632 mg gallic acid equivalents/g for a hexane stem fraction oil. Total flavonoid content was the highest in the leaves: ∼297 mg quercetin equivalents/g for a chloroform leaf fraction. At 1 μg/mL, only the crude ethanol extract oil was significantly cytotoxic to hepatocytes. Carpolobia lutea possesses anti-AChE activity and beneficial antioxidant capacity indicative of its potential development as a treatment of Alzheimer's and other diseases characterized by a cholinergic deficit.

Risk Factors of Pesticide Poisoning and Pesticide Users’ Cholinesterase Levels in Cotton Production Areas: Glazoué and Savè Townships, in Central Republic of Benin

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Vikkey, Hinson Antoine; Fidel, Dossou; Pazou Elisabeth, Yehouenou; Hilaire, Hountikpo; Hervé, Lawin; Badirou, Aguèmon; Alain, Koudafoke; Parfait, Houngbégnon; Fabien, Gounongbé; Benjamin, Fayomi

2017-01-01

Objective: To assess the degree of poisoning in farmers using the erythrocyte acetylcholinesterase (AChE) test before and after the exposure to pesticides in townships in central Benin (Glazoué and Savè) and to identify the associated risk factors. Methods: Using a cross-sectional study design, we recruited 264 farm pesticide sprayers, who have been working for at least 5 years. They completed a questionnaire and underwent the AChE test using the Test-mate Model 400 device (EQM Research Inc.) with a photometric sensor, based on the works of Ellman. Results: Organophosphate/pyrethroids were the most common pesticides used by at least 72.96% of the farmworkers. We observed an inhibition of AChE between pre-exposure and post-exposure (P = .002) for 60.61% of the farmworkers. Among them, 11.88% displayed more than 20% AChE inhibition. Conclusions: Pesticide poisoning is a reality, and AChE monitoring is urgently needed for farmworker surveillance. PMID:28469452

Risk Factors of Pesticide Poisoning and Pesticide Users' Cholinesterase Levels in Cotton Production Areas: Glazoué and Savè Townships, in Central Republic of Benin.

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Vikkey, Hinson Antoine; Fidel, Dossou; Elisabeth, Yehouenou Pazou; Hilaire, Hountikpo; Hervé, Lawin; Badirou, Aguèmon; Alain, Koudafoke; Parfait, Houngbégnon; Fabien, Gounongbé; Benjamin, Fayomi

2017-01-01

To assess the degree of poisoning in farmers using the erythrocyte acetylcholinesterase (AChE) test before and after the exposure to pesticides in townships in central Benin (Glazoué and Savè) and to identify the associated risk factors. Using a cross-sectional study design, we recruited 264 farm pesticide sprayers, who have been working for at least 5 years. They completed a questionnaire and underwent the AChE test using the Test-mate Model 400 device (EQM Research Inc.) with a photometric sensor, based on the works of Ellman. Organophosphate/pyrethroids were the most common pesticides used by at least 72.96% of the farmworkers. We observed an inhibition of AChE between pre-exposure and post-exposure ( P = .002) for 60.61% of the farmworkers. Among them, 11.88% displayed more than 20% AChE inhibition. Pesticide poisoning is a reality, and AChE monitoring is urgently needed for farmworker surveillance.

Risk Factors of Pesticide Poisoning and Pesticide Users’ Cholinesterase Levels in Cotton Production Areas: Glazoué and Savè Townships, in Central Republic of Benin

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Hinson Antoine Vikkey

2017-04-01

Full Text Available Objective: To assess the degree of poisoning in farmers using the erythrocyte acetylcholinesterase (AChE test before and after the exposure to pesticides in townships in central Benin (Glazoué and Savè and to identify the associated risk factors. Methods: Using a cross-sectional study design, we recruited 264 farm pesticide sprayers, who have been working for at least 5 years. They completed a questionnaire and underwent the AChE test using the Test-mate Model 400 device (EQM Research Inc. with a photometric sensor, based on the works of Ellman. Results: Organophosphate/pyrethroids were the most common pesticides used by at least 72.96% of the farmworkers. We observed an inhibition of AChE between pre-exposure and post-exposure ( P = .002 for 60.61% of the farmworkers. Among them, 11.88% displayed more than 20% AChE inhibition. Conclusions: Pesticide poisoning is a reality, and AChE monitoring is urgently needed for farmworker surveillance.

Study on the Highly Sensitive AChE Electrode Based on Multiwalled Carbon Nanotubes

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Shuping Zhang

2014-01-01

Full Text Available Using chitosan (CS as carrier, the method named layer-by-layer (LBL self-assembly modification to modify the glassy carbon electrode (GCE with multiwalled carbon nanotubes (MWNTs and acetylcholine esterase (AChE was proposed to prepare the acetylcholine esterase electrode with high sensitivity and stability. The modified electrode was used to detect pesticide of aldicarb, and the enzyme inhibition rate of the electrode showed good linearity with pesticide concentrations in the range of 10−10 g·L−1 to 10−3 g·L−1. The detection limit was 10−11 g·L−1. The modified electrode was also used to detect the actual sample, and the recovery rate range was from 97.72% to 107.15%, which could meet the rapid testing need of the aldicarb residue. After being stored in the phosphate buffer solution (PBS in 4°C for 30 days, the modified electrode showed good stability with the response current that was 80% of the original current.

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

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

2013-01-01

Even though technologies involving nano/microparticles have great potential, it is crucial to determine possible toxicity of these technological products before extensive use. Fullerenes C60 are nanomaterials with unique physicochemical and biological properties that are important for the development of many technological applications. The aim of this study was to evaluate the consequences of nonphotoexcited fullerene C60 exposure in brain acetylcholinesterase expression and activity, antioxidant responses, and oxidative damage using adult zebrafish as an animal model. None of the doses tested (7.5, 15, and 30 mg/kg) altered AChE activity, antioxidant responses, and oxidative damage when zebrafish were exposed to nonphotoexcited C60 nano/microparticles during 6 and 12 hours. However, adult zebrafish exposed to the 30 mg/kg dose for 24 hours have shown enhanced AChE activity and augmented lipid peroxidation (TBARS assays) in brain. In addition, the up-regulation of brain AChE activity was neither related to the transcriptional control (RT-qPCR analysis) nor to the direct action of nonphotoexcited C60 nano/microparticles on the protein (in vitro results) but probably involved a posttranscriptional or posttranslational modulation of this enzymatic activity. Taken together these findings provided further evidence of toxic effects on brain after C60 exposure. PMID:23865059

Genistein, a Phytoestrogen in Soybean, Induces the Expression of Acetylcholinesterase via G Protein-Coupled Receptor 30 in PC12 Cells

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Etta Y. L. Liu

2018-02-01

Full Text Available Genistein, 4′,5,7-trihydroxyisoflavone, is a major isoflavone in soybean, which is known as phytestrogen having known benefit to brain functions. Being a common phytestrogen, the possible role of genistein in the brain protection needs to be further explored. In cultured PC12 cells, application of genistein significantly induced the expression of neurofilaments (NFs, markers for neuronal differentiation. In parallel, the expression of tetrameric form of proline-rich membrane anchor (PRiMA-linked acetyl-cholinesterase (G4 AChE, a key enzyme to hydrolyze acetylcholine in cholinergic synapses, was induced in a dose-dependent manner: this induction included the associated protein PRiMA. The genistein-induced AChE expression was fully blocked by the pre-treatment of H89 (an inhibitor of protein kinase A, PKA and G15 (a selective G protein-coupled receptor 30 (GPR30 antagonist, which suggested a direct involvement of a membrane-bound estrogen receptor (ER, named as GPR30 in the cultures. In parallel, the estrogen-induced activation of GPR30 induced AChE expression in a dose-dependent manner. The genistein/estrogen-induced AChE expression was triggered by a cyclic AMP responding element (CRE located on the ACHE gene promoter. The binding of this CRE site by cAMP response element-binding protein (CREB induced ACHE gene transcription. In parallel, increased expression levels of miR132 and miR212 were found when cultured PC12 cells were treated with genistein or G1. Thus, a balance between production and destruction of AChE by the activation of GPR30 was reported here. We have shown for the first time that the activation of GPR30 could be one way for estrogen or flavonoids, possessing estrogenic properties, to enhance cholinergic functions in the brain, which could be a good candidate for possible treatment of neurodegenerative diseases.

Unmasking tandem site interaction in human acetylcholinesterase. Substrate activation with a cationic acetanilide substrate.

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Johnson, Joseph L; Cusack, Bernadette; Davies, Matthew P; Fauq, Abdul; Rosenberry, Terrone L

2003-05-13

Acetylcholinesterase (AChE) contains a narrow and deep active site gorge with two sites of ligand binding, an acylation site (or A-site) at the base of the gorge, and a peripheral site (or P-site) near the gorge entrance. The P-site contributes to catalytic efficiency by transiently binding substrates on their way to the acylation site, where a short-lived acyl enzyme intermediate is produced. A conformational interaction between the A- and P-sites has recently been found to modulate ligand affinities. We now demonstrate that this interaction is of functional importance by showing that the acetylation rate constant of a substrate bound to the A-site is increased by a factor a when a second molecule of substrate binds to the P-site. This demonstration became feasible through the introduction of a new acetanilide substrate analogue of acetylcholine, 3-(acetamido)-N,N,N-trimethylanilinium (ATMA), for which a = 4. This substrate has a low acetylation rate constant and equilibrates with the catalytic site, allowing a tractable algebraic solution to the rate equation for substrate hydrolysis. ATMA affinities for the A- and P-sites deduced from the kinetic analysis were confirmed by fluorescence titration with thioflavin T as a reporter ligand. Values of a >1 give rise to a hydrolysis profile called substrate activation, and the AChE site-specific mutant W86F, and to a lesser extent wild-type human AChE itself, showed substrate activation with acetylthiocholine as the substrate. Substrate activation was incorporated into a previous catalytic scheme for AChE in which a bound P-site ligand can also block product dissociation from the A-site, and two additional features of the AChE catalytic pathway were revealed. First, the ability of a bound P-site ligand to increase the substrate acetylation rate constant varied with the structure of the ligand: thioflavin T accelerated ATMA acetylation by a factor a(2) of 1.3, while propidium failed to accelerate. Second, catalytic rate

STRUCTURE-ACTIVITY RELATIONSHIP STUDY OF DITERPENES FOR TREATMENT OF ALZHEIMER'S DISEASE

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Gabriel F. dos Santos

Full Text Available Alzheimer's disease is an irreversible, degenerative and age-related disease which is growing more and more with the increase in life expectancy. Kaurane diterpenes are a class of natural products available in large amounts in nature and isolated from plants grown worldwide. In the present work¸ twenty-seven kaurane diterpenes of natural origin and some readily available derivatives were assayed for acetylcholinesterase inhibition and the structure-activity relationship was analyzed. The kaurenoic acid derivatives screened showed to be promising inhibitors of AChE, which could provide new leads for drugs to fight Alzheimer's disease symptoms. Among them, eleven compounds showed activities comparable or higher than the positive control galantamine. Existence of an allylic hydroxyl group showed to be an important structural feature for AChE inhibition. In addition, presence of free hydroxyl groups at C-17 and C-19, furnished a diol especially active, able to completely inhibit AChE.

Anti-Alzheimer's disease activity of compounds from the root bark of Morus alba L.

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Kuk, Eun Bi; Jo, A Ra; Oh, Seo In; Sohn, Hee Sook; Seong, Su Hui; Roy, Anupom; Choi, Jae Sue; Jung, Hyun Ah

2017-03-01

The inhibition of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-site amyloid precursor protein cleaving enzyme 1 (BACE1) plays important roles in prevention and treatment of Alzheimer's disease (AD). Among the individual parts of Morus alba L. including root bark, branches, leaves, and fruits, the root bark showed the most potent enzyme inhibitory activities. Therefore, the aim of this study was to evaluate the anti-AD activity of the M. alba root bark and its isolate compounds, including mulberrofuran G (1), albanol B (2), and kuwanon G (3) via inhibition of AChE, BChE, and BACE1. Compounds 1 and 2 showed strong AChE- and BChE-inhibitory activities; 1-3 showed significant BACE1 inhibitory activity. Based on the kinetic study with AChE and BChE, 2 and 3 showed noncompetitive-type inhibition; 1 showed mixed-type inhibition. Moreover, 1-3 showed mixed-type inhibition against BACE1. The molecular docking simulations of 1-3 demonstrated negative binding energies, indicating a high affinity to AChE and BACE1. The hydroxyl group of 1-3 formed hydrogen bond with the amino acid residues located at AChE and BACE1. Consequently, these results indicate that the root bark of M. alba and its active compounds might be promising candidates for preventive and therapeutic agents for AD.

Synthesis of some new 3-coumaranone and coumarin derivatives as dual inhibitors of acetyl- and butyrylcholinesterase.

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Alipour, Masoumeh; Khoobi, Mehdi; Nadri, Hamid; Sakhteman, Amirhossein; Moradi, Alireza; Ghandi, Mehdi; Foroumadi, Alireza; Shafiee, Abbas

2013-08-01

A novel series of coumarin and 3-coumaranone derivatives encompassing the phenacyl pyridinium moiety were synthesized and evaluated for their acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activity using Ellman's method. All compounds presented inhibitory activity against both AChE and BuChE in the micromolar range. The molecular docking simulations revealed that all compounds were dual binding site inhibitors of AChE. A kinetic study was performed and the mechanism of enzyme inhibition was proved to be of mixed type. All compounds were tested for their antioxidant activity and no significant activity was observed. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hyperglycemia induces memory impairment linked to increased acetylcholinesterase activity in zebrafish (Danio rerio).

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Capiotti, Katiucia Marques; De Moraes, Daiani Almeida; Menezes, Fabiano Peres; Kist, Luiza Wilges; Bogo, Maurício Reis; Da Silva, Rosane Souza

2014-11-01

Diabetes mellitus, which causes hyperglycemia, affects the central nervous system and can impairs cognitive functions, such as memory. The aim of this study was to investigate the effects of hyperglycemia on memory as well as on the activity of acethylcholinesterase. Hyperglycemia was induced in adult zebrafish by immersion in glucose 111mM by 14 days. The animals were divided in 4 groups: control, glucose-treated, glucose-washout 7-days and glucose-washout 14-days. We evaluated the performance in inhibitory avoidance task and locomotor activity. We also determined acethylcholinesterase activity and gene expression from whole brain. In order to counteract the effect of hyperglycemia underlined by effects on acethylcholinesterase activity, we treated the animals with galantamine (0.05ng/g), an inhibitor of this enzyme. Also we evaluated the gene expression of insulin receptor and glucose transporter from zebrafish brain. The hyperglycemia promoted memory deficit in adult zebrafish, which can be explained by increased AChE activity. The ache mRNA levels from zebrafish brain were decrease in 111mM glucose group and returned to normal levels after 7 days of glucose withdrawal. Insulin receptors (insra-1, insra-2, insrb-1 and insrb-2) and glut-3 mRNA levels were not significantly changed. Our results also demonstrated that galantamine was able to reverse the memory deficit caused by hyperglycemia, demonstrating that these effects involve modulation of AChE activity. These data suggest that the memory impairment induced by hyperglycemia is underlined by the cholinergic dysfunction caused by the mechanisms involving the control of acetylcholinesterase function and gene expression. Copyright © 2014 Elsevier B.V. All rights reserved.

Nanoparticle-Based Electrochemical Immunosensor for the Detection of Phosphorylated Acetylcholinesterase: An Exposure Biomarker of Organophosphate Pesticides and Nerve AgentsOrganophosphate Pesticides and Nerve Agents

Energy Technology Data Exchange (ETDEWEB)

Liu, Guodong; Wang, Jun; Barry, Richard C.; Petersen, Catherine E.; Timchalk, Charles; Gassman, Paul L.; Lin, Yuehe

2008-11-01

A nanoparticle-based electrochemical immunosensor has been developed for the detection of phosphorylated acetylcholinesterase (AChE) adducts, which is a potential exposure biomarker for organophosphate pesticides (OP) and chemical warfare nerve agent exposures. Zirconia nanoparticles (ZrO2 NPs) were used as selective sorbents to capture the phosphorylated AChE adduct, and quantum dots (ZnS@CdS, QDs) were used as tags to label monoclonal anti-AChE antibody to track the immunorecognition events. The sandwich-like immunoreactions were performed among the ZrO2 NPs, which were pre-coated on a screen printed electrode (SPE) by electrodeposition, phosphorylated AChE and QD-anti-AChE. The captured QD tags were determined on the SPE by electrochemical stripping analysis of its metallic component (cadmium) after an acid-dissolution step. Paraoxon was used as a model OP insecticide to prepare the phosphorylated AChE adduct to demonstrate the proof of principle for this sensor technology. The paraoxon-AChE adduct was characterized by Fourier Transform Infrared Spectrum, and the binding affinity of anti-AChE to the paraoxon-AChE was validated with an enzyme-linked immunosorbent assay. The parameters (e.g., amount of ZrO2 NP, QD-anti-AChE concentration,) that govern the electrochemical response of immunosensors were optimized. The voltammetric response of the immunosensor is highly linear over the range of 10 pM to 4 nM paraoxon-AChE, and the limit of detection is estimated to be 8 pM. This new nanoparticle-based electrochemical immunosensor thus provides a sensitive and quantitative tool for biomonitoring exposure to OP pesticides and nerve agents.

Nickel in Soil Modifies Sensitivity to Diazinon Measured by the Activity of Acetylcholinesterase, Catalase, and Glutathione S-Transferase in Earthworm Eisenia fetida

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Agnieszka Zawisza-Raszka

2013-01-01

Full Text Available Nickel in typical soils is present in a very low concentration, but in the contaminated soils it occurs in locally elevated concentrations. The aim of this study was to examine the effect of nickel in the concentrations of 300 (very high, close to LOEC for reproduction and 900 (extremely high, close to LOEC for mortality mg/kg dry soil on the life history and acetylcholinesterase, catalase, and glutathione S-transferase activities in earthworm Eisenia fetida and to establish how nickel modifies the sensitivity to organophosphorous pesticide—diazinon. Cocoons production and juveniles’ number were significantly lower only in groups exposed to Ni in the concentration of 900 mg/kg dry soil for two months. Diazinon administration diminished the AChE activity in the GI tract and in the body wall. The interaction between diazinon and nickel was observed, and, in consequence, the AChE activity after the pesticide treatment was similar to controls in worms preexposed to nickel. Both pesticide administration and exposure to nickel caused an increase in the GST activity in examined organs and CAT activity in body wall. Both biometric and development data and simple enzymatic analysis, especially the AChE and GST, show a Ni pretreatment effect on the subsequent susceptibility to pesticide.

Development of Cholinesterase Inhibitors Using (a)-Lipoic Acid-benzyl Piperazine Hybrid Molecules

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Kim, Beomcheol; Lee, Seunghwan; Jang, Mi; Shon, Min Young; Park, Jeong Ho [Hanbat National Univ., Daejeon (Korea, Republic of)

2013-11-15

A series of hybrid molecules between (α)-lipoic acid (ALA) and benzyl piperazines were synthesized and their in vitro cholinesterase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)] inhibitory activities were evaluated. Even though the parent compounds did not show any inhibitory activity against cholinesterase (ChE), all hybrid molecules showed BuChE inhibitory activity. Some hybrid compounds also displayed AChE inhibitory activity. Specifically, ALA-1-(3-methylbenzyl)piperazine (15) was shown to be an effective inhibitor of both BuChE (IC{sub 50} = 2.3 ± 0.7 μM) and AChE (IC{sub 50} = 30.31 ± 0.64 μM). An inhibition kinetic study using compound 15 indicated a mixed inhibition type. Its binding affinity (K{sub i}) value to BuChE is 2.91 ± 0.15 μM.

Efeito do extrato da casca de Syzygium cumini sobre a atividade da acetilcolinesterase em ratos normais e diabéticos Syzygium cumini bark extract effect on acetylcholinesterase activity in normal and diabetic rats

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Cinthia Melazzo Mazzanti

2004-06-01

Full Text Available Este estudo verificou a eficiência do extrato etanólico da casca de Syzygium cumini sobre o sistema colinérgico de ratos normais e diabéticos induzidos com aloxano. Os animais foram divididos em grupo controle (C, tratado com Syzygium cumini (TS, diabético (D e diabético tratado com Syzygium cumini (DS. A atividade da acetilcolinesterase (AChE foi analisada nas seguintes estruturas cerebrais: cerebelo, córtex, estriado e hipocampo. O extrato etanólico da casca de Syzygium cumini na dose de 1g.kg-1 foi administrado diariamente por um período de trinta dias. Foi verificado após este período que o extrato inibiu a atividade da AChE no cerebelo e córtex cerebral dos ratos do grupo DS (PThe present study verified the efficiency of the bark ethanol extract of Syzygium cumini on the cholinergic system of normal and alloxan induced diabetic rats. Thirty-nine female rats were divided in control (C, treated with Syzygium cumini (TS, diabetic (D and diabetic treated with Syzygium cumini (DS. The activity of acetylcholinesterase (AChE was analyzed in the following cerebral structures: cerebellum, cortex, striatum and hippocampus. The extract of the bark of Syzygium cumini in the dose of 1g.kg-1 was administered orally daily for a period of thirty days. After this period the extract inhibited the activity of the AChE in the cerebellum and cerebral cortex of the rats in the DS group (P<0.05 as, compared to TS. In the striatum there was a significant increase in the activity of the AChE in rats of the TS group (P<0.01 when compared to the C group, and in the hippocampus there was no significant variation. These results indicate that the bark extract of "Jambolão"has an inhibitory effect on AChE in the cerebellum and cerebral cortex and an stimulatory effect on striatum, indicating a possible alteration in the functionality of the cholinergic system in such cerebral structures.

A molecular dynamics study of components of the ginger (Zingiber officinale) extract inside human acetylcholinesterase: implications for Alzheimer disease.

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Cuya, Teobaldo; Baptista, Leonardo; Celmar Costa França, Tanos

2017-11-23

Components of ginger (Zingiber officinale) extracts have been described as potential new drug candidates against Alzheimer disease (AD), able to interact with several molecular targets related to the AD treatment. However, there are very few theoretical studies in the literature on the possible mechanisms of action by which these compounds can work as potential anti-AD drugs. For this reason, we performed here docking, molecular dynamic simulations and mmpbsa calculations on four components of ginger extracts former reported as active inhibitors of human acetylcholinesterase (HssAChE), and compared our results to the known HssAChE inhibitor and commercial drug in use against AD, donepezil (DNP). Our findings points to two among the compounds studied: (E)-1,7-bis(4-hydroxy-3-methoxyphenyl)hept-4-en-3-on and 1-(3,4-dihydroxy-5-methoxyphenyl)-7-(4-hydroxy-3- ethoxyphenyl) heptane-3,5-diyl diacetate, as promising new HssAChE inhibitors that could be as effective as DNP. We also mapped the binding of the studied compounds in the different binding pockets inside HssAChE and established the preferred interactions to be favored in the design of new and more efficient inhibitors.

Biochemical toxicology studies of methomyl and its kinetic reaction with cholinesterase in rats

International Nuclear Information System (INIS)

Tawfik, S.M.; Abdel-Hamid, F.M.

2001-01-01

The effect of the pesticide methomyl on acetylcholinesterase activities in brain and blood of male rats in vivo and the kinetics involved in their reaction in vitro were studied. Also, its effect on peroxidase action of catalase in vivo was studied using 14C - formate. The results showed that methomyl is a competitive inhibitor for acetylcholinesterase and the concentration levels that caused 50% inhibition of the enzyme activity were 2.1 x 10-2 M and 1.9 x 10-4 for brain and blood- Ache, respectively. The inhibition of acetylcholinesterase activity decreased to 67.5 % at the time of appearance of toxicity symptoms. The radioactivity eliminated in both the expired air and in urine was reduced

Novel Method of Preparation and Activity Research on Arctigenin from Fructus Arctii

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Cai, Enbo; Han, Jiahong; Yang, Limin; Zhang, Weiyuan; Zhao, Yan; Chen, Qiulian; Guo, Meng; He, Xinhong

2018-01-01

Background: Arctigenin has many pharmacological activities with clinical significance and is derived from Arctium lappa L. However, the present extraction method is inefficient and does not have meaningful industrial production. Objective: A new method to directly prepare arctigenin was established by combining enzyme-assisted extraction and central composite design. Arctigenin's further pharmacological activity was also surveyed in vitro. Materials and Methods: β-D-Glucosidase, a food-grade enzyme, was added directly to the fruits of A. lappa L. to hydrolyze the arctiin to arctigenin, and the obtained samples were subsequently subjected to ethanol (30%, v/v) extraction. The pharmacological activity of the extraction and arctigenin was determined by inhibiting acetylcholinesterase (AChE) and scavenging nitrite. Results: The factors investigated include the enzyme concentration (0.5%–2.5%), ultrasound time (10 min−3 0 min), and extraction temperature (30°C–50°C). From the analysis of the results by Design-Expert (V8.0.6), the optimal extraction conditions were obtained: enzyme concentration (1.4%), ultrasound time (25 min), and extraction temperature (45°C). The highest yield of arctigenin, obtained under the optimal conditions was 6.39%, representing an increase of 28.15% compared to the reference extraction without enzyme processing. The IC50 values of the extraction and arctigenin, respectively, for inhibiting AChE were 0.572 mg/ml and 0.462 mg/ml, and those for nitrite-scavenging were 34.571 mg/ml and 17.49 mg/ml. Conclusions: The results demonstrate that using an enzyme directly in the production is an effective means for extracting arctigenin from Fructus arctii. The extraction has the activities of inhibiting AChE and scavenging nitrite, probably because there has arctigenin in it. It is implied that the extraction and arctigenin could contribute to human health in clinical applications. SUMMARY The new method of adding enzyme directly to the

Novel Method of Preparation and Activity Research on Arctigenin from Fructus Arctii.

Science.gov (United States)

Cai, Enbo; Han, Jiahong; Yang, Limin; Zhang, Weiyuan; Zhao, Yan; Chen, Qiulian; Guo, Meng; He, Xinhong

2018-01-01

Arctigenin has many pharmacological activities with clinical significance and is derived from Arctium lappa L. However, the present extraction method is inefficient and does not have meaningful industrial production. A new method to directly prepare arctigenin was established by combining enzyme-assisted extraction and central composite design. Arctigenin's further pharmacological activity was also surveyed in vitro . β-D-Glucosidase, a food-grade enzyme, was added directly to the fruits of A. lappa L. to hydrolyze the arctiin to arctigenin, and the obtained samples were subsequently subjected to ethanol (30%, v/v) extraction. The pharmacological activity of the extraction and arctigenin was determined by inhibiting acetylcholinesterase (AChE) and scavenging nitrite. The factors investigated include the enzyme concentration (0.5%-2.5%), ultrasound time (10 min -3 0 min), and extraction temperature (30°C-50°C). From the analysis of the results by Design-Expert (V8.0.6), the optimal extraction conditions were obtained: enzyme concentration (1.4%), ultrasound time (25 min), and extraction temperature (45°C). The highest yield of arctigenin, obtained under the optimal conditions was 6.39%, representing an increase of 28.15% compared to the reference extraction without enzyme processing. The IC 50 values of the extraction and arctigenin, respectively, for inhibiting AChE were 0.572 mg/ml and 0.462 mg/ml, and those for nitrite-scavenging were 34.571 mg/ml and 17.49 mg/ml. The results demonstrate that using an enzyme directly in the production is an effective means for extracting arctigenin from Fructus arctii. The extraction has the activities of inhibiting AChE and scavenging nitrite, probably because there has arctigenin in it. It is implied that the extraction and arctigenin could contribute to human health in clinical applications. The new method of adding enzyme directly to the preparation of arctigenin was carried out instead of preparing arctigenin by two

Recent advances in evaluation of oxime efficacy in nerve agent poisoning by in vitro analysis

International Nuclear Information System (INIS)

Worek, F.; Eyer, P.; Aurbek, N.; Szinicz, L.; Thiermann, H.

2007-01-01

The availability of highly toxic organophosphorus (OP) warfare agents (nerve agents) underlines the necessity for an effective medical treatment. Acute OP toxicity is primarily caused by inhibition of acetylcholinesterase (AChE). Reactivators (oximes) of inhibited AChE are a mainstay of treatment, however, the commercially available compounds, obidoxime and pralidoxime, are considered to be rather ineffective against various nerve agents, e.g. soman and cyclosarin. This led to the synthesis and investigation of numerous oximes in the past decades. Reactivation of OP-inhibited AChE is considered to be the most important reaction of oximes. Clinical data from studies with pesticide-poisoned patients support the assumption that the various reactions between AChE, OP and oxime, i.e. inhibition, reactivation and aging, can be investigated in vitro with human AChE. In contrast to animal experiments such in vitro studies with human tissue enable the evaluation of oxime efficacy without being affected by species differences. In the past few years numerous in vitro studies were performed by different groups with a large number of oximes and methods were developed for extrapolating in vitro data to different scenarios of human nerve agent poisoning. The present status in the evaluation of new oximes as antidotes against nerve agent poisoning will be discussed

Development of multifunctional, heterodimeric isoindoline-1,3-dione derivatives as cholinesterase and β-amyloid aggregation inhibitors with neuroprotective properties.

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Guzior, Natalia; Bajda, Marek; Skrok, Mirosław; Kurpiewska, Katarzyna; Lewiński, Krzysztof; Brus, Boris; Pišlar, Anja; Kos, Janko; Gobec, Stanislav; Malawska, Barbara

2015-03-06

The presented study describes the synthesis, pharmacological evaluation (AChE and BuChE inhibition, beta amyloid anti-aggregation effect and neuroprotective effect), molecular modeling and crystallographic studies of a novel series of isoindoline-1,3-dione derivatives. The target compounds were designed as dual binding site acetylcholinesterase inhibitors with an arylalkylamine moiety binding at the catalytic site of the enzyme and connected via an alkyl chain to a heterocyclic fragment, capable of binding at the peripheral anionic site of AChE. Among these molecules, compound 15b was found to be the most potent and selective AChE inhibitor (IC50EeAChE = 0.034 μM). Moreover, compound 13b in addition to AChE inhibition (IC50 EeAChE = 0.219 μM) possesses additional properties, such as the ability to inhibit Aβ aggregation (65.96% at 10 μM) and a neuroprotective effect against Aβ toxicity at 1 and 3 μM. Compound 13b emerges as a promising multi-target ligand for the further development of the therapy for age-related neurodegenerative disorders. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Self-assembly of SiO2 nanoparticles for the potentiometric detection of neurotransmitter acetylcholine and its inhibitor.

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Arruda, Izabela G; Guimarães, Francisco E G; Ramos, Romildo J; Vieira, Nirton C S

2014-09-01

The detection and quantification of neurotransmitter acetylcholine (ACh) are relevant because modifications in the ACh levels constitute a threat to human health. The biological regulator of this neurotransmitter is acetylcholinesterase (AChE), an enzyme that catalyzes the hydrolysis of ACh to choline and acetic acid. However, its activity is inhibited in the presence of organophosphate and carbamate pesticides, compromising the degradation of the neurotransmitter. There has been a growing interest in faster and more sensitive detection systems that include new methods and materials for the determination of the ACh concentration. This paper proposes a potentiometric biosensor for the detection of neurotransmitter ACh and its inhibitors, specifically organophosphate pesticide methamidophos. The biosensor is based on a self-assembled platform formed by poly(allylamine) hydrochloride (PAH) and silicon dioxide nanoparticles (SiO2-Np) that contains the immobilized enzyme AChE. First, the responses of the biosensor were investigated for different concentrations of ACh in buffer solutions. After quantifying ACh, the inhibition of AChE in the presence of methamidophos was determined, enabling the quantification of methamidophos expressed as the percentage of enzyme inhibition. The potential advantages of this biosensor include simplicity in building the electrode, possible production on an industrial scale, limited need for qualified personnel to operate the device and low processing cost.

Acetylcholinesterase inhibitory activity of pyrrolizidine alkaloids from Echium confusum Coincy.

Science.gov (United States)

Benamar, Houari; Tomassini, Lamberto; Venditti, Alessandro; Marouf, Abderrazak; Bennaceur, Malika; Serafini, Mauro; Nicoletti, Marcello

2017-06-01

Four pyrrolizidine alkaloids, namely 7-O-angeloyllycopsamine N-oxide 1, echimidine N-oxide 2, echimidine 3 and 7-O-angeloylretronecine 4, were isolated for the first time from the whole plant ethanolic extract of Echium confusum Coincy, through bioassay-guided approach. Their structures were determined by spectroscopic means. All the isolates compounds showed moderate activities in inhibiting AChE, with IC50 0.276-0.769.

Design, Synthesis, and Biological Evaluation of 2-(Benzylamino-2-HydroxyalkylIsoindoline-1,3-Diones Derivatives as Potential Disease-Modifying Multifunctional Anti-Alzheimer Agents

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Dawid Panek

2018-02-01

Full Text Available The complex nature of Alzheimer’s disease calls for multidirectional treatment. Consequently, the search for multi-target-directed ligands may lead to potential drug candidates. The aim of the present study is to seek multifunctional compounds with expected activity against disease-modifying and symptomatic targets. A series of 15 drug-like various substituted derivatives of 2-(benzylamino-2-hydroxyalkylisoindoline-1,3-diones was designed by modification of cholinesterase inhibitors toward β-secretase inhibition. All target compounds have been synthesized and tested against eel acetylcholinesterase (eeAChE, equine serum butyrylcholinesterase (eqBuChE, human β-secretase (hBACE-1, and β-amyloid (Aβ-aggregation. The most promising compound, 12 (2-(5-(benzylamino-4-hydroxypentylisoindoline-1,3-dione, displayed inhibitory potency against eeAChE (IC50 = 3.33 μM, hBACE-1 (43.7% at 50 μM, and Aβ-aggregation (24.9% at 10 μM. Molecular modeling studies have revealed possible interaction of compound 12 with the active sites of both enzymes—acetylcholinesterase and β-secretase. In conclusion: modifications of acetylcholinesterase inhibitors led to the discovery of a multipotent anti-Alzheimer’s agent, with moderate and balanced potency, capable of inhibiting acetylcholinesterase, a symptomatic target, and disease-modifying targets: β-secretase and Aβ-aggregation.

Syntheses and biological evaluation of {sup 18}F-labeled 3-(1-benzyl-piperidin-4-yl)-1-(1-methyl-1H-indol-3-yl)propan-1-ones for in vivo mapping of acetylcholinesterase

Energy Technology Data Exchange (ETDEWEB)

Choe, Y.-S. E-mail: yschoe@samsung.co.kr; Oh, S.-J.; Shim, Insop; Naruto, Shunji; Chi, Dae Yoon; Kim, Sang Eun; Lee, Kyung-Han; Choi, Yong; Kim, B.-T

2000-04-01

We synthesized novel {sup 18}F-labeled acetylcholinesterase (AChE) inhibitors, 3-[1-(3- and 4-[{sup 18}F]fluoromethylbenzyl)piperidin-4-yl]-1-(1-methyl-1H-indol-3-yl)propan- 1-ones ([{sup 18}F]1 and [{sup 18}F]2) and 3-[1-(4-[{sup 18}F]fluorobenzyl)piperidin-4-yl]-1-(1-methyl-1H-indol-3-yl)propan- 1-one ([{sup 18}F]3) in high yields (decay-corrected, 25%-40%) and with high effective specific activities (>37 GBq/{mu}mol). Tissue distribution studies of the [{sup 18}F]1 and the [{sup 18}F]3 in mice showed the nonspecific bindings in brain regions, with metabolic defluorination of the [{sup 18}F]1. The result suggests that these radioligands may not be suitable agents for in vivo mapping of AChE, despite their potent in vitro anti-AChE activities.

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

International Nuclear Information System (INIS)

Bonnot-Lours, S.; Crouzel, C.; Prenant, C.; Hinnen, F.

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 [ 11 C]methylisocyanate with eseroline. [ 11 C]Methylisocyanate was obtained by heating [ 11 C]acetylchloride with tetrabutylammonium azide in toluene. The synthesis of [ 11 C]CH 3 COC1 involves the carbonation of methylmagnesium bromide in THF with cyclotron produced [ 11 C]carbon dioxide and the addition of phthaloyl dichloride. The [ 11 C]methylisocyanate is distilled into a solution of eseroline in ether with a small piece of sodium. After 10 minutes at 25 o C, the solution is purified by HPLC and the appropriate fraction collected. Starting with 55.5 GBq (1.5 Ci) of [ 11 C]carbon dioxide, 0.92-1.48 GBq (25-40 mCi) of [ 11 C]Physostigmine are obtained 57 minutes after EOB. (author)

Hypothyroidism Enhanced Ectonucleotidases and Acetylcholinesterase Activities in Rat Synaptosomes can be Prevented by the Naturally Occurring Polyphenol Quercetin.

Science.gov (United States)

Baldissarelli, Jucimara; Santi, Adriana; Schmatz, Roberta; Abdalla, Fátima Husein; Cardoso, Andréia Machado; Martins, Caroline Curry; Dias, Glaecir R Mundstock; Calgaroto, Nicéia Spanholi; Pelinson, Luana Paula; Reichert, Karine Paula; Loro, Vania Lucia; Morsch, Vera Maria Melchiors; Schetinger, Maria Rosa Chitolina

2017-01-01

Thyroid hormones have an influence on the functioning of the central nervous system. Furthermore, the cholinergic and purinergic systems also are extensively involved in brain function. In this context, quercetin is a polyphenol with antioxidant and neuroprotective properties. This study investigated the effects of (MMI)-induced hypothyroidism on the NTPDase, 5'-nucleotidase, adenosine deaminase (ADA), and acetylcholinesterase (AChE) activities in synaptosomes of rats and whether the quercetin can prevent it. MMI at a concentration of 20 mg/100 mL was administered for 90 days in the drinking water. The animals were divided into six groups: control/water (CT/W), control/quercetin 10 mg/kg, control/quercetin 25 mg/kg, methimazole/water (MMI/W), methimazole/quercetin 10 mg/kg (MMI/Q10), and methimazole/quercetin 25 mg/kg (MMI/Q25). On the 30th day, hormonal dosing was performed to confirm hypothyroidism, and the animals were subsequently treated with 10 or 25 mg/kg quercetin for 60 days. NTPDase activity was not altered in the MMI/W group. However, treatment with quercetin decreased ATP and ADP hydrolysis in the MMI/Q10 and MMI/Q25 groups. 5'-nucleotidase activity increased in the MMI/W group, but treatments with 10 or 25 mg/kg quercetin decreased 5'-nucleotidase activity. ADA activity decreased in the CT/25 and MMI/Q25 groups. Furthermore, AChE activity was reduced in all groups with hypothyroidism. In vitro tests also demonstrated that quercetin per se decreased NTPDase, 5'-nucleotidase, and AChE activities. This study demonstrated changes in the 5'-nucleotidase and AChE activities indicating that purinergic and cholinergic neurotransmission are altered in this condition. In addition, quercetin can alter these parameters and may be a promising natural compound with important neuroprotective actions in hypothyroidism.

RNA interference of acetylcholinesterase in the Asian citrus psyllid, Diaphorina citri, increases its susceptibility to carbamate and organophosphate insecticides.

Science.gov (United States)

Kishk, Abdelaziz; Hijaz, Faraj; Anber, Helmy A I; AbdEl-Raof, Tsamoh K; El-Sherbeni, AbdEl-Hakeem D; Hamed, Sobhy; Killiny, Nabil

2017-11-01

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Lividae) transmits the Candidatus Liberibacter asiaticus, which causes citrus greening disease or Huanglongbing, (HLB). To date, there is no efficient cure for HLB disease and the control of D. citri using insecticides became the most important tools for the management of HLB. However, the extensive use of insecticides could increase D. citri resistance to these insecticides. The objective of this study was to investigate the effect of RNA interference of acetylcholinesterase (AChE) on the mortality and susceptibility of D. citri to the four major insecticides used in Florida. In this study, we used a consensus sequence derived from the two AChE genes and cholinesterase 2-like (ChE-2-like) gene to target all of the three genes. Treatment with dsRNA-AChE increased the mortality percentages of both nymphs and adults of D. citri. The mortality percentage increased with the increase in the concentration of applied dsRNA-AChE, and the highest mortality (> 60%) was observed at the highest applied concentration (125ng/μl). Treatments of nymphs or adults with dsRNA-AChE down-regulated the expression of the three targeted genes of D. citri. Silencing of AChE and ChE in D. citri nymphs increased the susceptibility of emerged adults to chlorpyrifos and carbaryl, which act as AChE inhibitors. However, treatment with dsRNA-AChE did not increase the susceptibility of emerged adults to imidacloprid, which acts as an agonist of nicotinic acetylcholine receptors. In the same manner, treatment of adults with dsRNA-AChE increased their susceptibility to chlorpyrifos and carbaryl, but did not affect their susceptibility to imidacloprid. The ANOVA did not show any significant increase in susceptibility of D. citri adults to fenpropathrin after treatment with dsRNA-AChE, either as nymphs or as adults. However, simple linear regression showed that treatment with dsRNA-AChE increased D. citri susceptibility to fenpropathrin

Cholinesterase reactivators and bioscavengers for pre- and post-exposure treatments of organophosphorus poisoning.

Science.gov (United States)

Masson, Patrick; Nachon, Florian

2017-08-01

Organophosphorus agents (OPs) irreversibly inhibit acetylcholinesterase (AChE) causing a major cholinergic syndrome. The medical counter-measures of OP poisoning have not evolved for the last 30 years with carbamates for pretreatment, pyridinium oximes-based AChE reactivators, antimuscarinic drugs and neuroprotective benzodiazepines for post-exposure treatment. These drugs ensure protection of peripheral nervous system and mitigate acute effects of OP lethal doses. However, they have significant limitations. Pyridostigmine and oximes do not protect/reactivate central AChE. Oximes poorly reactivate AChE inhibited by phosphoramidates. In addition, current neuroprotectants do not protect the central nervous system shortly after the onset of seizures when brain damage becomes irreversible. New therapeutic approaches for pre- and post-exposure treatments involve detoxification of OP molecules before they reach their molecular targets by administrating catalytic bioscavengers, among them phosphotriesterases are the most promising. Novel generation of broad spectrum reactivators are designed for crossing the blood-brain barrier and reactivate central AChE. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms. © 2017 International Society for Neurochemistry.

Acetylcholinesterase immobilized capillary reactors coupled to protein coated magnetic beads: A new tool for plant extract ligand screening

Science.gov (United States)

Vanzolini, Kenia Lourenço; Jiang, Zhengjin; Zhang, Xiaoqi; Vieira, Lucas Campos Curcino; Corrêa, Arlene Gonçalvez; Cardoso, Carmen Lucia; Cass, Quezia Bezerra; Moaddel, Ruin

2013-01-01

The use of immobilized capillary enzyme reactors (ICERs) and enzymes coated to magnetic beads ((NT or CT)-MB) for ligand screening has been adopted as a new technique of high throughput screening (HTS). In this work the selected target was the enzyme acetylcholinesterase (AChE), which acts on the central nervous system and is a validated target for the treatment of Alzheimer’s disease, as well as for new insecticides. A new approach for the screening of plant extracts was developed based on the ligand fishing experiments and zonal chromatography. For that, the magnetic beads were used for the ligand fishing experiments and capillary bioreactors for the activity assays. The latter was employed also under non-linear conditions to determine the affinity constants of known ligands, for the first time, as well as for the active fished ligand. PMID:24148457

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

International Nuclear Information System (INIS)

Areche, Carlos; Cejas, Patricia; Thomas, Pablo; San-Martin, Aurelio; Astudillo, Luis; Gutierrez, Margarita; Loyola, Luis A.

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 in the genus Azorella. (author)

Dgroup: DG01132 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available ucoma agents; Agents for Alzheimer-type dementia ACHE [HSA:43] [KO:K01049] ... ...esterase inhibitor ... DG01593 ... Acetylcholinesterase inhibitor ATC code: S01EB05 V03AB19 Acetylcholinesterase (AChE) inhibitor, Antigla

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

International Nuclear Information System (INIS)

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

2015-01-01

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 50 and 1.5 × LD 50 of toxin and 10 min after exposure to 1.5 × LD 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 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 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 exhibited its safety

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

Energy Technology Data Exchange (ETDEWEB)

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

Nicotine-Induced Effects on Nicotinic Acetylcholine Receptors (nAChRs), Ca2+ and Brain-Derived Neurotrophic Factor (BDNF) in STC-1 Cells.

Science.gov (United States)

Qian, Jie; Mummalaneni, Shobha K; Alkahtani, Reem M; Mahavadi, Sunila; Murthy, Karnam S; Grider, John R; Lyall, Vijay

2016-01-01

In addition to the T2R bitter taste receptors, neuronal nicotinic acetylcholine receptors (nAChRs) have recently been shown to be involved in the bitter taste transduction of nicotine, acetylcholine and ethanol. However, at present it is not clear if nAChRs are expressed in enteroendocrine cells other than beta cells of the pancreas and enterochromaffin cells, and if they play a role in the synthesis and release of neurohumoral peptides. Accordingly, we investigated the expression and functional role of nAChRs in enteroendocrine STC-1 cells. Our studies using RT-PCR, qRT-PCR, immunohistochemical and Western blotting techniques demonstrate that STC-1 cells express several α and β nAChR subunits. Exposing STC-1 cells to nicotine acutely (24h) or chronically (4 days) induced a differential increase in the expression of nAChR subunit mRNA and protein in a dose- and time-dependent fashion. Mecamylamine, a non-selective antagonist of nAChRs, inhibited the nicotine-induced increase in mRNA expression of nAChRs. Exposing STC-1 cells to nicotine increased intracellular Ca2+ in a dose-dependent manner that was inhibited in the presence of mecamylamine or dihydro-β-erythroidine, a α4β2 nAChR antagonist. Brain-derived neurotrophic factor (BDNF) mRNA and protein were detected in STC-1 cells using RT-PCR, specific BDNF antibody, and enzyme-linked immunosorbent assay. Acute nicotine exposure (30 min) decreased the cellular content of BDNF in STC-1 cells. The nicotine-induced decrease in BDNF was inhibited in the presence of mecamylamine. We also detected α3 and β4 mRNA in intestinal mucosal cells and α3 protein expression in intestinal enteroendocrine cells. We conclude that STC-1 cells and intestinal enteroendocrine cells express nAChRs. In STC-1 cells nAChR expression is modulated by exposure to nicotine in a dose- and time-dependent manner. Nicotine interacts with nAChRs and inhibits BDNF expression in STC-1 cells.

Confirming a Role for α9nAChRs and SK Potassium Channels in Type II Hair Cells of the Turtle Posterior Crista

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Xiaorong Xu Parks

2017-11-01

Full Text Available In turtle posterior cristae, cholinergic vestibular efferent neurons (VENs synapse on type II hair cells, bouton afferents innervating type II hair cells, and afferent calyces innervating type I hair cells. Electrical stimulation of VENs releases acetylcholine (ACh at these synapses to exert diverse effects on afferent background discharge including rapid inhibition of bouton afferents and excitation of calyx-bearing afferents. Efferent-mediated inhibition is most pronounced in bouton afferents innervating type II hair cells near the torus, but becomes progressively smaller and briefer when moving longitudinally through the crista toward afferents innervating the planum. Sharp-electrode recordings have inferred that efferent-mediated inhibition of bouton afferents requires the sequential activation of alpha9-containing nicotinic ACh receptors (α9*nAChRs and small-conductance, calcium-dependent potassium channels (SK in type II hair cells. Gradations in the strength of efferent-mediated inhibition across the crista likely reflect variations in α9*nAChRs and/or SK activation in type II hair cells from those different regions. However, in turtle cristae, neither inference has been confirmed with direct recordings from type II hair cells. To address these gaps, we performed whole-cell, patch-clamp recordings from type II hair cells within a split-epithelial preparation of the turtle posterior crista. Here, we can easily visualize and record hair cells while maintaining their native location within the neuroepithelium. Consistent with α9*nAChR/SK activation, ACh-sensitive currents in type II hair cells were inward at hyperpolarizing potentials but reversed near −90 mV to produce outward currents that typically peaked around −20 mV. ACh-sensitive currents were largest in torus hair cells but absent from hair cells near the planum. In current clamp recordings under zero-current conditions, ACh robustly hyperpolarized type II hair cells. ACh

Generation and Evaluation of PEGylated Recombinant Human Acetylcholinesterase as an Optimal OP-Bioscavenger

Science.gov (United States)

2009-04-27

treatment of OP intoxication. (5) To demonstrate that the slow aging rate of the soman-inhibited PEG F338A-AChE allows restoration of its...the conditions for purification of P. pastoris-produced rHuAChE. We found that microfiltration and ultrafiltration of the P. pastoris growth medium

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

Energy Technology Data Exchange (ETDEWEB)

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).

Specificity of carboxylesterase protection against the toxicity of organophosphorus compounds. (Reannouncement with new availability information)

Energy Technology Data Exchange (ETDEWEB)

Maxwell, D.M.

1992-12-31

The ability of endogenous carboxylesterase (CaE) to protect against the lethal effects of a variety of organophosphorus (OP) compounds was examined in rats. The in vivo protection provided by endogenous CaE was measured by the difference in the LD50 values of OP compounds in controlrats and rats whose CaE activity had been inhibited by sc injection with2 mg/kg of 2-(O cresyl)-4H-1,3,2-benzodi oxaphosphorin-2-oxide. Endogenous CaE provided significant protection against the in vivo toxicity of soman, sarin, tabun, and paraoxon, but not against dichlorvos, diisopropyl fluorophosphate, or ethoxymethyl-S-2- (DIISOPROPYLAMINO)ETHYL THIOPHOSPHONATE (VX). The relationship between the in vivo CaE protection against OP compounds and their relative reactivities with CaE and acetylcholinesterase (AChE) was evaluated by measuring the in vitro bimolecular rate constants (ki) for inhibition of plasma CaE and brain AChE. Except for VX, ki values for CaE inhibition varied <10-fold while ki values for AChE inhibition varied 105-fold. Chemical warfare agents, Nerve agents, Organophosphoruscompound soman, VX, Carboxylesterase, Protection, Pretreatment.

Inhibition of acetylcholinesterase activity in brain and behavioral analysis in adult rats after chronic administration of fenproporex.

Science.gov (United States)

Rezin, Gislaine T; Scaini, Giselli; Ferreira, Gabriela K; Cardoso, Mariane R; Gonçalves, Cinara L; Constantino, Larissa S; Deroza, Pedro F; Ghedim, Fernando V; Valvassori, Samira S; Resende, Wilson R; Quevedo, João; Zugno, Alexandra I; Streck, Emilio L

2012-12-01

Fenproporex is an amphetamine-based anorectic and it is rapidly converted in vivo into amphetamine. It elevates the levels of extracellular dopamine in the brain. Acetylcholinesterase is a regulatory enzyme which is involved in cholinergic synapses and may indirectly modulate the release of dopamine. Thus, we investigated whether the effects of chronic administration of fenproporex in adult rats alters acquisition and retention of avoidance memory and acetylcholinesterase activity. Adult male Wistar rats received repeated (14 days) intraperitoneal injection of vehicle or fenproporex (6.25, 12.5 or 25 mg/kg i.p.). For behavioral assessment, animals were submitted to inhibitory avoidance (IA) tasks and continuous multiple trials step-down inhibitory avoidance (CMIA). Acetylcholinesterase activity was measured in the prefrontal cortex, hippocampus, hypothalamus and striatum. The administration of fenproporex (6.25, 12.5 and 25 mg/kg) did not induce impairment in short and long-term IA or CMIA retention memory in rats. In addition, longer periods of exposure to fenproporex administration decreased acetylcholinesterase activity in prefrontal cortex and striatum of rats, but no alteration was verified in the hippocampus and hypothalamus. In conclusion, the present study showed that chronic fenproporex administration decreased acetylcholinesterase activity in the rat brain. However, longer periods of exposure to fenproporex did not produce impairment in short and long-term IA or CMIA retention memory in rats.

Effects of two oxadiazolidinones on cholinesterases and acetylcholine receptors

International Nuclear Information System (INIS)