Tacrine (THA), a long withdrawn drug, is still a popular scaffold used in medicinal chemistry, mainly for its good reactivity and multi-targeted effect. However, THA-associated hepatotoxicity is still an issue and must be considered in drug discovery based on the THA scaffold. Following our previously identified hit compound 7-phenoxytacrine (7-PhO-THA), we systematically explored the chemical space with 30 novel derivatives, with a focus on low hepatotoxicity, anticholinesterase action, and antagonism at the GluN1/GluN2B subtype of the NMDA receptor. Applying the down-selection process based on in vitro and in vivo pharmacokinetic data, two candidates, I-52 and II-52, selective GluN1/GluN2B inhibitors thanks to the interaction with the ifenprodil-binding site, have entered in vivo pharmacodynamic studies. Finally, compound I-52, showing only minor affinity to AChE, was identified as a lead candidate with favorable behavioral and neuroprotective effects using open-field and prepulse inhibition tests, along with scopolamine-based behavioral and NMDA-induced hippocampal lesion models. Our data show that compound I-52 exhibits low toxicity often associated with NMDA receptor ligands, and low hepatotoxicity, often related to THA-based compounds.
- MeSH
- acetylcholinesterasa metabolismus MeSH
- Alzheimerova nemoc * farmakoterapie MeSH
- cholinesterasové inhibitory chemie MeSH
- cholinesterasy MeSH
- lékové postižení jater * MeSH
- lidé MeSH
- neuroprotektivní látky * farmakologie terapeutické užití MeSH
- piperidiny * MeSH
- receptory N-methyl-D-aspartátu MeSH
- takrin chemie MeSH
- vazebná místa MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Publikační typ
- tisková chyba MeSH
17β-hydroxysteroid dehydrogenase type 10 (17β-HSD10) is a multifunctional mitochondrial enzyme and putative drug target for the treatment of various pathologies including Alzheimer's disease or some types of hormone-dependent cancer. In this study, a series of new benzothiazolylurea-based inhibitors were developed based on the structure-activity relationship (SAR) study of previously published compounds and predictions of their physico-chemical properties. This led to the identification of several submicromolar inhibitors (IC50 ∼0.3 μM), the most potent compounds within the benzothiazolylurea class known to date. The positive interaction with 17β-HSD10 was further confirmed by differential scanning fluorimetry and the best molecules were found to be cell penetrable. In addition, the best compounds weren't found to have additional effects for mitochondrial off-targets and cytotoxic or neurotoxic effects. The two most potent inhibitors 9 and 11 were selected for in vivo pharmacokinetic study after intravenous and peroral administration. Although the pharmacokinetic results were not fully conclusive, it seemed that compound 9 was bioavailable after peroral administration and could penetrate into the brain (brain-plasma ratio 0.56).
BACKGROUND: The acetylcholinesterase inhibitor donepezil is administered as a treatment for Alzheimer's disease (AD). However, the appropriate donepezil dosage is still a matter of debate. METHODS: Forty AD patients receiving 10 mg/day of donepezil were randomly divided into four groups based on the time of plasma and cerebrospinal fluid (CSF) sampling: 6 h (n = 5), 12 h (n = 12), 18 h (n = 6) and 24 h (n = 17) after donepezil administration. High-performance liquid chromatography measured the donepezil concentration in plasma samples and CSF samples collected at 4-time points. RESULTS: Plasma and CSF levels among the groups were not significantly different. Conversely, the CSF/plasma donepezil concentration ratio considerably increased in the 24 h group compared to the 6 h (p < 0.005) and 12 h (p < 0.05) groups. CONCLUSION: The measurement of the CSF/plasma donepezil concentration ratio could be used to better evaluate the optimal dose of donepezil.
- MeSH
- acetylcholinesterasa MeSH
- Alzheimerova nemoc * krev mozkomíšní mok farmakoterapie MeSH
- cholinesterasové inhibitory * krev mozkomíšní mok terapeutické užití MeSH
- donepezil * krev mozkomíšní mok terapeutické užití MeSH
- indany terapeutické užití farmakologie MeSH
- lidé MeSH
- piperidiny farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- randomizované kontrolované studie MeSH
Schizophrenia is a serious mental disorder without a fully understood pathomechanism, but which involves dysregulation of neurotransmitters and their receptors. The best option for the management of schizophrenia comprises so-called multi-target ligands, similar to the third generation of neuroleptics. Dopamine type 2 receptors (D2Rs) are the main target in the treatment of schizophrenia, in particular for mitigation of the positive symptoms. Due to the high expression of 5-hydroxytryptamine type 3 receptors (5-HT3Rs) in human brain areas responsible for emotional behavior, motivation, and cognitive function, 5-HT3Rs represent a potential target for modulating the cognitive and negative symptoms of schizophrenia. Here we present the design, synthesis, and both in vitro and in vivo biological evaluation of 1,4-disubstituted aromatic piperazines. Screening of in vitro properties revealed the two most promising drug candidates (21 and 24) which were found to be potent D2Rs and moderate 5-HT3R antagonists, and which were forwarded to in vivo studies in Wistar rats. Considering toxicity, administration of the maximal feasible dose of 21 (2 mg/kg) did not produce any side effects. By contrast, the higher solubility of 24 led to revelation of mild and temporary side effects at the dose of 20 mg/kg. Importantly, both 21 and 24 showed facile crossing of the blood-brain barrier, even exerting higher levels in the brain in comparison to plasma. In a behavioral study using the acute amphetamine model of psychosis, we showed that compound 24 ameliorated both positive and negative effects of amphetamine including hyperlocomotion, social impairments, and disruption of prepulse inhibition. The effect of the highest dose (10 mg/kg) was comparable to the effect of the reference dose of aripiprazole (1 mg/kg).
Nerve agents pose a real threat to both the military and civil populations, but the current treatment of the poisoning is unsatisfactory. Thus, we studied the efficacy of prophylactic use of memantine alone or in combination with clinically used reversible acetylcholinesterase inhibitors (pyridostigmine, donepezil, rivastigmine) against soman. In addition, we tested their influence on post-exposure therapy consisting of atropine and asoxime. Pyridostigmine alone failed to decrease the acute toxicity of soman. But all clinically used acetylcholinesterase inhibitors administered alone reduced the acute toxicity, with donepezil showing the best efficacy. The combination of memantine with reversible acetylcholinesterase inhibitors attenuated soman acute toxicity significantly. The pretreatment administered alone or in combinations influenced the efficacy of post-exposure treatment in a similar fashion: (i) pyridostigmine or memantine alone did not affect the antidotal treatment, (ii) centrally acting reversible acetylcholinesterase inhibitors alone increased the antidotal treatment slightly, (iii) combination of memantine with reversible acetylcholinesterase inhibitors increased the antidotal treatment more markedly. In conclusion, memantine alone failed to decrease the acute toxicity of soman or increase post-exposure antidotal treatment efficacy. The combination of memantine with donepezil significantly increased post-exposure effectiveness (together 5.12, pretreatment alone 1.72). Both drugs, when applied together, mitigate soman toxicity and boost post-exposure treatment.
- MeSH
- acetylcholinesterasa metabolismus MeSH
- antiparkinsonika aplikace a dávkování MeSH
- cholinesterasové inhibitory aplikace a dávkování toxicita MeSH
- donepezil aplikace a dávkování MeSH
- dopaminové látky aplikace a dávkování MeSH
- kombinovaná farmakoterapie MeSH
- memantin aplikace a dávkování MeSH
- myši MeSH
- preexpoziční profylaxe metody MeSH
- soman toxicita MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Tacrine is a classic drug whose efficacy against neurodegenerative diseases is still shrouded in mystery. It seems that besides its inhibitory effect on cholinesterases, the clinical benefit is co-determined by NMDAR-antagonizing activity. Our previous data showed that the direct inhibitory effect of tacrine, as well as its 7-methoxy derivative (7-MEOTA), is ensured via a "foot-in-the-door" open-channel blockage, and that interestingly both tacrine and 7-MEOTA are slightly more potent at the GluN1/GluN2A receptors when compared with the GluN1/GluN2B receptors. Here, we report that in a series of 30 novel tacrine derivatives, designed for assessment of structure-activity relationship, blocking efficacy differs among different compounds and receptors using electrophysiology with HEK293 cells expressing the defined types of NMDARs. Selected compounds (4 and 5) potently inhibited both GluN1/GluN2A and GluN1/GluN2B receptors; other compounds (7 and 23) more effectively inhibited the GluN1/GluN2B receptors; or the GluN1/GluN2A receptors (21 and 28). QSAR study revealed statistically significant model for the data obtained for inhibition of GluN1/Glu2B at -60 mV expressed as IC50 values, and for relative inhibition of GluN1/Glu2A at +40 mV caused by a concentration of 100 μM. The models can be utilized for a ligand-based virtual screening to detect potential candidates for inhibition of GluN1/Glu2A and/or GluN1/Glu2B subtypes. Using in vivo experiments in rats we observed that unlike MK-801, the tested novel compounds did not induce hyperlocomotion in open field, and also did not impair prepulse inhibition of startle response, suggesting minimal induction of psychotomimetic side effects. We conclude that tacrine derivatives are promising compounds since they are centrally available subtype-specific inhibitors of the NMDARs without detrimental behavioral side-effects.
- MeSH
- acetylcholinesterasa chemie genetika metabolismus MeSH
- butyrylcholinesterasa chemie metabolismus MeSH
- cholinesterasové inhibitory chemie metabolismus farmakologie MeSH
- hematoencefalická bariéra účinky léků metabolismus MeSH
- krysa rodu rattus MeSH
- kvantitativní vztahy mezi strukturou a aktivitou MeSH
- lidé MeSH
- lokomoce účinky léků MeSH
- membránové potenciály účinky léků MeSH
- myši inbrední ICR MeSH
- myši MeSH
- poločas MeSH
- potkani Wistar MeSH
- psi MeSH
- racionální návrh léčiv MeSH
- receptory N-methyl-D-aspartátu antagonisté a inhibitory genetika metabolismus MeSH
- rekombinantní proteiny biosyntéza chemie MeSH
- takrin chemie metabolismus farmakologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Oxime reactivators of acetylcholinesterase (AChE) represent an integral part of standard antidote treatment of organophosphate poisoning. Oxime K869 is a novel bisquaternary non-symmetric pyridinium aldoxime with two pyridinium rings connected by a tetramethylene bridge where two chlorines modify the pyridinium ring bearing the oxime moiety. Based on in vitro assays, K869 is a potent AChE and butyrylcholinesterase (BChE) reactivator. For the investigation of the basic pharmacokinetic properties of K869 after its intramuscular application, new HPLC-UV and LC-MS/MS methods were developed and validated for its determination in rat body fluids and tissues. In this study, the SPE procedure for sample pretreatment was optimized as an alternative to routine protein precipitation widely used in oxime pharmacokinetics studies. K869 oxime is quickly absorbed into the central compartment reaching its maximum in plasma (39 ± 4 μg/mL) between 15 and 20 min. The majority of K869 was eliminated by kidneys via urine when compared with biliary excretion. However, only a limited amount of K869 (65 ± 4 ng/g of brain tissue) was found in the brain 30 min after oxime administration. Regarding the brain/plasma ratio calculated (less than 1%), the penetration of K869 into the brain did not exceed conventionally used oximes.
- MeSH
- acetylcholinesterasa MeSH
- cholinesterasové inhibitory MeSH
- chromatografie kapalinová MeSH
- krysa rodu rattus MeSH
- oximy MeSH
- reaktivátory cholinesterázy * MeSH
- tandemová hmotnostní spektrometrie MeSH
- tělesné tekutiny * MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
To date, the only treatments developed for poisoning by organophosphorus compounds, the most toxic chemical weapons of mass destruction, have exhibited limited efficacy and versatility. The available causal antidotes are based on reactivation of the enzyme acetylcholinesterase (AChE), which is rapidly and pseudo-irreversibly inhibited by these agents. In this study, we developed a novel series of monoquaternary reactivators combining permanently charged moieties tethered to position 6- of 3-hydroxypyridine-2-aldoxime reactivating subunit. Highlighted representatives (21, 24, and 27; also coded as K1371, K1374, and K1375, respectively) that contained 1-phenylisoquinolinium, 7-amino-1-phenylisoquinolinium and 4-carbamoylpyridinium moieties as peripheral anionic site ligands, respectively, showed efficacy superior or comparable to that of the clinically used standards. More importantly, these reactivators exhibited wide-spectrum efficacy and were minutely investigated via determination of their reactivation kinetics in parallel with molecular dynamics simulations to study their mechanisms of reactivation of the tabun-inhibited AChE conjugate. To further confirm the potential applicability of these candidates, a mouse in vivo assay was conducted. While K1375 had the lowest acute toxicity and the most suitable pharmacokinetic profile, the oxime K1374 with delayed elimination half-life was the most effective in ameliorating the signs of tabun toxicity. Moreover, both in vitro and in vivo, the versatility of the agents was substantially superior to that of clinically used standards. Their high efficacy and broad-spectrum capability make K1374 and K1375 promising candidates that should be further investigated for their potential as nerve agents and insecticide antidotes.
- MeSH
- acetylcholinesterasa účinky léků metabolismus MeSH
- antidota chemická syntéza chemie farmakologie MeSH
- myši inbrední BALB C MeSH
- myši MeSH
- oximy chemická syntéza chemie farmakologie MeSH
- reaktivátory cholinesterázy chemická syntéza chemie farmakologie MeSH
- simulace molekulární dynamiky MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
3-Quinuclidinyl benzilate (QNB) is an anticholinergic compound that affects the nervous system. Its hallucinogenic action has led to its potential utility as an incapacitating warfare agent, and it is listed in Schedule 2 by the Organization for the Prohibition of Chemical Weapons. Although this compound has been known for a long time, limited information is available regarding its metabolism and mass spectrometric data of the metabolites, the information that could facilitate the identification of QNB in case of suspected intoxication. To the best of our knowledge, the analytical methods previously described in the literature are based on outdated procedures, which may result in a significantly lower number of observable metabolites. The aim of this work was to obtain deeper insight into QNB biotransformation using a combination of in vitro and in vivo approach. The development of a suitable method for the separation and detection of metabolites using mass spectrometry together with the identification of reliable diagnostic fragments for the unambiguous identification of QNB metabolites in the different biological matrices are also presented in this work. A screening of rat plasma, urine and tissue homogenates revealed 26 new metabolites related to the cytochrome P450 biotransformation pathway, which involves N-oxidation and hydroxylation(s) followed by O-methylation and O-glucuronosylation within phase II of the metabolism. A study showed that the brain is not metabolically active in the case of QNB and that the metabolites do not cross the blood-brain barrier; thus, the toxicodynamic effects are due to QNB itself. In addition, in vitro experiments performed using isolated human liver microsomes revealed N-oxidation as the principal metabolic pathway in human tissue. In light of current global events, the abuse of QNB by terrorists or para-military groups is a real possibility, and our findings may improve the detection systems used in laboratories involved in postexposure investigations.
- MeSH
- biotransformace MeSH
- chinuklidinylbenzilát MeSH
- hmotnostní spektrometrie MeSH
- krysa rodu rattus MeSH
- mozek * MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
