Nerve agents belong to the most dangerous chemical warfare agents and can be/were misused by terrorists. Effective prophylaxis and treatment is necessary to diminish their effect. General principles of prophylaxis are summarized (protection against acetylcholinesterase inhibition, detoxification, treatment "in advance" and use of different drugs). They are based on the knowledge of mechanism of action of nerve agents. Among different examinations, it is necessary to test prophylactic effectivity in vivo and compare the results with protection in vitro. Chemical and biological approaches to the development of new prophylactics would be applied simultaneously during this research. Though the number of possible prophylactics is relatively high, the only four drugs were introduced into military medical practice. At present, pyridostigmine seems to be common prophylactic antidote; prophylactics panpal (tablets with pyridostigmine, trihexyphenidyl and benactyzine), transant (transdermal patch containing HI-6) are other means introduced into different armies as prophylactics. Scavenger commercionally available is Protexia®. Future development will be focused on scavengers, and on other drugs either reversible cholinesterase inhibitors (e.g., huperzine A, gallantamine, physostigmine, acridine derivatives) or other compounds.

• Klíčová slova
• Nerve agents, antidotes, cholinesterases, in vitro, in vivo, prophylaxis, scavengers.,
• MeSH
• cholinesterasy metabolismus   MeSH
• lidé MeSH
• molekulární modely MeSH
• nervová bojová látka chemie   farmakologie   MeSH
• reaktivátory cholinesterasy chemie   farmakologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• cholinesterasy MeSH
• nervová bojová látka MeSH
• reaktivátory cholinesterasy MeSH

In this study, we determined the effect of methoxime (MMB-4), asoxime (HI-6), obidoxime (LüH-6), trimedoxime (TMB-4), and pralidoxime (2-PAM) on redox homeostasis in vitro. Cultured human hepatoma cells (HepG2) were exposed to oximes at concentrations equivalent to their IC50 (assessed using MTT assay) and evaluated 1, 4 and 24 h after incubation. Additionally, intact, early and late apoptotic and necrotic cells were quantified by microcapillary flow cytometry. Intracellular levels of oxygen/nitrogen species were determined using two fluorescent probes (2',7'-dichlorodihydrofluorescein diacetate and dihydroethidium). Malondialdehyde and 3-nitrotyrosine were measured by LC-MS/MS. Non-protein thiols and non-protein disulfides were evaluated using HPLC-UV to reflect antioxidant capacity. Oxidative and nitrosative stress was induced by LüH-6, TMB-4 and MMB-4, whereas 2-PAM and HI-6 appeared as weak oxidative stressors with no activity towards nitrosative stress in HepG2 cells. Based on these results, bisquartenary oxime reactivators containing two functional oxime groups at the position 4 of pyridinium ring appear as more intense oxidative and nitrosative inducers. Activation of apoptosis and necrosis do not seem to correlate with generation of RONS. On the other hand, both processes rather reflect MDA concentrations, i.e. the damage of biomolecules.

• Klíčová slova
• Cytotoxicity, HPLC-UV, LC-MS/MS, Nitrosative stress, Oxidative stress, Oxime,
• MeSH
• acetylcholinesterasa metabolismus   MeSH
• buňky Hep G2 MeSH
• lidé MeSH
• oxidační stres účinky léků   MeSH
• oximy farmakologie   MeSH
• reaktivátory cholinesterasy farmakologie   MeSH
• reaktivní formy dusíku metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acetylcholinesterasa MeSH
• oximy MeSH
• reaktivátory cholinesterasy MeSH
• reaktivní formy dusíku MeSH
• reaktivní formy kyslíku MeSH

Novel tacrine-benzyl quinolone carboxylic acid (tacrine-BQCA) hybrids were designed based on multi-target directed ligands (MTLDs) paradigm, synthesized and evaluated in vitro as inhibitors of human acetylcholinesterase (hAChE) and human butyrylcholinesterase (hBChE). Tacrine moiety is represented herein as 7-methoxytacrine, 6-chlorotacrine or unsubstituted tacrine forming three different families of seven members, i.e. 21 compounds in overall. Introducing BQCA, a positive modulator of M1 muscarinic acetylcholine receptors (mAChRs), the action of novel compounds on M1 mAChRs was evaluated via Fluo-4 NW assay on the Chinese hamster ovarian (CHO-M1WT2) cell line. All the novel tacrine-BQCA hybrids were able to block the action of hAChE and hBChE in micromolar to nanomolar range. The hAChE kinetic profile of 5p was found to be mixed-type which is consistent with our docking experiments. Moreover, selected ligands were assessed for their potential hepatotoxicity on HepG2 cell line and presumable permeation through the blood-brain barrier by PAMPA assay. Expected agonistic profile towards M1 mAChRs delivered by BQCA moiety was not confirmed. From all the hybrids, 5o can be highlighted as non-selective cholinesterase inhibitor (hAChE IC50 = 74.5 nM; hBChE IC50 = 83.3 nM) with micromolar antagonistic activity towards M1 mAChR (IC50 = 4.23 μM). A non-selective pattern of cholinesterase inhibition is likely to be valuable during the onset as well as later stages of AD.

• Klíčová slova
• 7-Methoxytacrine, Acetylcholinesterase, Acetylcholinesterase inhibitor, Alzheimer's disease, BQCA, Butyrylcholinesterase, Multi-target directed ligands, Positive allosteric modulator of muscarinic receptor, Tacrine,
• MeSH
• acetylcholinesterasa metabolismus   MeSH
• Alzheimerova nemoc farmakoterapie   metabolismus   MeSH
• buněčné linie MeSH
• butyrylcholinesterasa metabolismus   MeSH
• chinoliny chemie   farmakologie   MeSH
• cholinesterasové inhibitory chemická syntéza   chemie   farmakologie   MeSH
• Cricetulus MeSH
• lidé MeSH
• molekulární struktura MeSH
• takrin chemie   farmakologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 1-(4-methoxybenzyl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid MeSH Prohlížeč
• acetylcholinesterasa MeSH
• butyrylcholinesterasa MeSH
• chinoliny MeSH
• cholinesterasové inhibitory MeSH
• takrin MeSH

Chemical warfare agents constitute an increasing threat to both military and civilian populations. Therefore, effective prophylactic approaches are urgently needed. Herein, we present a novel hybrid compound which is able not only to keep acetylcholinesterase resistant to organophosphate (OP) inhibitors, but also to serve as an enzyme reactivator in the case of OP intoxication.

• Publikační typ
• časopisecké články MeSH

Organophosphorus inhibitors (OP) of acetylcholinesterase (AChE) represent a group of highly toxic compounds. The treatment of OP intoxication is, however, insufficiently ensured. Currently, two main categories of drugs-anticholinergics and oxime reactivators- are employed as antidotes. Oximes have been reported to act at several levels of the cholinergic transmission, and among the non-reactivation effects, the interaction with cholinergic receptors stands out. This review addresses issues correlated with non-reactivating effects of oxime reactivators with a special focus on the muscarinic and nicotinic receptors, but involvement of other cholinergic structures such as AChE and choline uptake carriers are discussed too. It can be concluded that the oxime reactivators show a variation in their antagonistic effect on the muscarinic and nicotinic receptors, which is likely to be of significance in the treatment of OP poisoning. In vitro data reported oximes to exert higher efficacy on the muscarinic M2 subtype than on the AChE. However, this effect seemed to be subtype specific since the antagonistic M3 effect was lower. Also, and importantly, the antimuscarinic effect was larger than that on nicotinic receptors. Even though atropine showed a much higher muscarinic antagonism, it is supposed that non-reactivation properties of oxime reactivators play a significant role in the treatment of OP poisoning.

• MeSH
• acetylcholinesterasa metabolismus   MeSH
• antidota terapeutické užití   MeSH
• atropin farmakologie   MeSH
• cholin metabolismus   MeSH
• cholinergní antagonisté farmakologie   MeSH
• cholinergní látky farmakologie   MeSH
• cholinesterasové inhibitory metabolismus   toxicita   MeSH
• inhibiční koncentrace 50 MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• močový měchýř účinky léků   metabolismus   MeSH
• nikotinové receptory účinky léků   metabolismus   MeSH
• organofosfáty metabolismus   toxicita   MeSH
• otrava organofosfáty farmakoterapie   metabolismus   MeSH
• oximy farmakologie   MeSH
• reaktivátory cholinesterasy farmakologie   MeSH
• receptory muskarinové účinky léků   metabolismus   MeSH
• svalová kontrakce účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• acetylcholinesterasa MeSH
• antidota MeSH
• atropin MeSH
• cholin MeSH
• cholinergní antagonisté MeSH
• cholinergní látky MeSH
• cholinesterasové inhibitory MeSH
• nikotinové receptory MeSH
• organofosfáty MeSH
• oximy MeSH
• reaktivátory cholinesterasy MeSH
• receptory muskarinové MeSH

Organophosphorus poisoning manifests as a cholinergic syndrome due to an inhibition of acetylcholinesterase. It is treated symptomatically by anticholinergics and oxime reactivators are used as causal antidotes. Reactivators possess a complex mechanism of action and interact at various levels of the cholinergic transmission. The aim of this study was to investigate the effect of standard oxime reactivators (HI-6, obidoxime, trimedoxime, methoxime and pralidoxime) on the hemicholinium-3 sensitive carriers, which are involved in the high-affinity choline uptake (HACU) transport, a key regulatory step in the synthesis of acetylcholine. The activity of the carriers was estimated in vitro on hippocampal synaptosomes using the substrate (3H)-choline and the competitive inhibitor (3H)-hemicholinium-3. Furthermore, the effect of the reactivators on the fluidity of hippocampal membranes was assessed. All tested compounds, except methoxime, showed an acute inhibitory effect on the carriers, however, only at μM concentrations. Trimedoxime showed the highest potency to inhibit HACU among all tested compounds (I(max) 62%, IC(50)=3 μM). All compounds, except HI-6, influenced also a membrane fluidity in the region of the hydrophilic heads of phospholipid bilayer, nevertheless, only methoxime was able to penetrate more deeply into the hydrocarbon core. We suggest that the direct interaction of oxime reactivators with the carrier protein (HI-6 and trimedoxime) and/or the changes in carrier conformation mediated by alterations in membrane fluidity (trimedoxime, obidoxime and pralidoxime) could occur here. The influence of reactivators on the carriers could be unfavorable in the case of their prolonged administration in vivo. From this point of view, the application of methoxime appears to be the best.

• MeSH
• acetylcholinesterasa metabolismus   MeSH
• anizotropie MeSH
• buněčná membrána účinky léků   metabolismus   MeSH
• cholin metabolismus   MeSH
• fluidita membrány účinky léků   fyziologie   MeSH
• hemicholinium 3 metabolismus   MeSH
• hipokampus účinky léků   metabolismus   MeSH
• krysa rodu Rattus MeSH
• membránové transportní proteiny účinky léků   metabolismus   MeSH
• potkani Wistar MeSH
• reaktivátory cholinesterasy metabolismus   farmakologie   MeSH
• synaptozomy účinky léků   metabolismus   MeSH
• tritium MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• acetylcholinesterasa MeSH
• cholin MeSH
• choline transporter MeSH Prohlížeč
• hemicholinium 3 MeSH
• membránové transportní proteiny MeSH
• reaktivátory cholinesterasy MeSH
• tritium MeSH

Current treatment of organophosphorus poisoning, resulting in overstimulation and desensitization of muscarinic and nicotinic receptors by acetylcholine (ACh), consists of the administration of atropine and oxime reactivators. However, no versatile oxime reactivator has been developed yet and some mortality still remains after application of standard atropine treatment, probably due to its lack of antinicotinic action. In our study, we focused on the interesting non-acetylcholinesterase property of oximes, i.e. antinicotinic effect of reactivators. Two standard reactivators (HI-6, obidoxime) and two new compounds (K027 and K203) were chosen for in vitro (patch clamp) and in vivo (nerve-evoked muscle contraction) testings. Both examinations showed antinicotinic effects of the reactivators. In vitro inhibition of acetylcholine-evoked currents by obidoxime, HI-6 and K203 was equivalent while K027 was less potent. Similar order of potency was observed by the in vivo examinations. We thus confirm previous in vitro results, which describe antinicotinic effects of oxime reactivators, and furthermore, we show in vivo antagonism of oxime reactivators exerted by the inhibition of ACh effect on the nicotinic receptor in the neuromuscular junction. Taking together, the effects of tested oxime reactivators indicate an antagonism on both embryonic and adult form of the muscle nicotinic receptors.

• MeSH
• krysa rodu Rattus MeSH
• nikotinové receptory fyziologie   MeSH
• nikotinoví antagonisté chemie   farmakologie   MeSH
• obidoxim chlorid farmakologie   MeSH
• oximy chemie   farmakologie   MeSH
• potkani Sprague-Dawley MeSH
• pyridinové sloučeniny chemie   farmakologie   MeSH
• reaktivátory cholinesterasy chemie   farmakologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• asoxime chloride MeSH Prohlížeč
• nikotinové receptory MeSH
• nikotinoví antagonisté MeSH
• obidoxim chlorid MeSH
• oximy MeSH
• pyridinové sloučeniny MeSH
• reaktivátory cholinesterasy MeSH

The antidotal treatment of organophosphorus poisoning is still a problematic issue since no versatile antidote has been developed yet. In our study, we focused on an interesting property, which does not relate to the reactivation of inhibited acetylcholinesterase (AChE) of some oximes, but refers to their anti-muscarinic effects which may contribute considerably to their treatment efficacy. One standard reactivator (HI-6) and two new compounds (K027 and K203) have been investigated for their antimuscarinic properties. Anti-muscarinic effects were studies by means of an in vitro stimulated atrium preparation (functional test), the [(3)H]-QNB binding assay and G-protein coupled receptor assay (GPCR, beta-Arrestin Assay). Based on the functional data HI-6 demonstrates the highest anti-muscarinic effect. However, only when comparing [(3)H]-QNB binding results and GPCR data, K203 shows a very promising compound with regard to anti-muscarinic potency. The therapeutic impact of these findings has been discussed.

• MeSH
• acetylcholinesterasa metabolismus   MeSH
• agonisté muskarinových receptorů farmakologie   MeSH
• antagonisté muskarinových receptorů farmakologie   MeSH
• chinuklidinylbenzilát metabolismus   MeSH
• elektrická stimulace MeSH
• krysa rodu Rattus MeSH
• oximy metabolismus   farmakologie   MeSH
• oxotremorin analogy a deriváty   farmakologie   MeSH
• potkani Wistar MeSH
• pyridinové sloučeniny metabolismus   farmakologie   MeSH
• reaktivátory cholinesterasy metabolismus   farmakologie   MeSH
• receptory muskarinové účinky léků   MeSH
• receptory spřažené s G-proteiny metabolismus   MeSH
• srdeční frekvence účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• acetylcholinesterasa MeSH
• agonisté muskarinových receptorů MeSH
• antagonisté muskarinových receptorů MeSH
• asoxime chloride MeSH Prohlížeč
• chinuklidinylbenzilát MeSH
• oximy MeSH
• oxotremorin MeSH
• oxotremorine M MeSH Prohlížeč
• pyridinové sloučeniny MeSH
• reaktivátory cholinesterasy MeSH
• receptory muskarinové MeSH
• receptory spřažené s G-proteiny MeSH

The oxime reactivator K112 is a member of the new group of xylene linker-containing AChE reactivators. Its cholinergic properties could be of importance at OP poisoning and are not related to the AChE reactivation that has been studied. It has been found that, despite of reactivating potency, this compound has additional effects. These cholinergic effects include a weak inhibition of AChE (IC(50)=43.8 ± 4.88 μM), inhibition of binding to the porcine muscarinic M2 receptor (IC(50)=4.36 μM) and finally, the inhibition of HACU (68.4 ± 9.9%), a key regulatory step in the synthesis of ACh. The inhibition of the binding of (3H)-HC-3 (64.7 ± 4.7%) and the influence on the membrane fluidity have also been observed. Blocking properties of K112 on the muscarinic receptors have been revealed in the in vitro experiment (rat urinary bladder) and in the in vivo experiment (rat heart BPM) as well. All these cholinergic properties could significantly contribute to the antidotal effect of K112 at the poisoning by the organophosphates.

• MeSH
• acetylcholinesterasa metabolismus   MeSH
• cholinesterasové inhibitory chemie   farmakologie   MeSH
• fluidita membrány účinky léků   MeSH
• hipokampus účinky léků   enzymologie   MeSH
• hladké svalstvo účinky léků   enzymologie   MeSH
• krysa rodu Rattus MeSH
• močový měchýř účinky léků   enzymologie   MeSH
• otrava organofosfáty MeSH
• otrava farmakoterapie   enzymologie   MeSH
• oximy chemie   farmakologie   MeSH
• potkani Sprague-Dawley MeSH
• potkani Wistar MeSH
• prasata MeSH
• pyridinové sloučeniny chemie   farmakologie   MeSH
• reaktivátory cholinesterasy chemie   farmakologie   MeSH
• receptor muskarinový M2 antagonisté a inhibitory   MeSH
• rekombinantní proteiny antagonisté a inhibitory   MeSH
• srdce účinky léků   MeSH
• srdeční frekvence účinky léků   MeSH
• svalová kontrakce účinky léků   MeSH
• synaptozomy účinky léků   enzymologie   MeSH
• techniky in vitro MeSH
• vazba proteinů MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 4,4'-bis(hydroxyiminomethyl)-1,10-(1,2-phenylenedimethyl)bispyridinium MeSH Prohlížeč
• acetylcholinesterasa MeSH
• cholinesterasové inhibitory MeSH
• oximy MeSH
• pyridinové sloučeniny MeSH
• reaktivátory cholinesterasy MeSH
• receptor muskarinový M2 MeSH
• rekombinantní proteiny MeSH

The poisoning with organophosphorus compounds represents a life threatening danger especially in the time of terroristic menace. No universal antidote has been developed yet and other therapeutic approaches not related to reactivation of acetylcholinesterase are being investigated. This review describes the main features of the cholinergic system, cholinergic receptors, cholinesterases and their inhibitors. It also focuses on the organophosphorus nerve agents, their properties, effects and a large part describes various possibilities in treatments, mainly traditional oxime therapies based on reactivation of AChE. Furthermore, non-cholinesterase coupled antidotal effects of the oximes are thoroughly discussed. These antidotal effects principally include oxime interactions with muscarinic and nicotinic receptors.

• MeSH
• acetylcholin metabolismus   MeSH
• antidota chemie   metabolismus   farmakologie   MeSH
• chemické bojové látky * otrava   MeSH
• cholinesterasy metabolismus   MeSH
• lidé MeSH
• organofosforové sloučeniny antagonisté a inhibitory   MeSH
• otrava organofosfáty MeSH
• receptory cholinergní metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• acetylcholin MeSH
• antidota MeSH
• chemické bojové látky * MeSH
• cholinesterasy MeSH
• organofosforové sloučeniny MeSH
• receptory cholinergní MeSH