RESUMO
In view of the multifactorial nature of Alzheimer's disease (AD), multitarget small molecules (MTSM) represent the most potent and attractive therapeutic strategy to design new drugs for Alzheimer's disease therapy. The new MTSM KojoTacrines (KTs) were designed and synthesized by juxtaposition of selected pharmacophoric motifs from kojic acid and tacrine. Among them, 11-amino-2-(hydroxymethyl)-12-(3-methoxyphenyl)-7,9,10,12-tetrahydropyrano [2',3':5,6] pyrano[2,3-b]quinolin-4(8H)-one (KT2d) was identified as less-hepatotoxic than tacrine, at higher concentration, a moderate, but selective human acetylcholinesterase inhibitor (IC50 = 4.52 ± 0.24 µM), as well as an antioxidant agent (TE = 4.79) showing significant neuroprotection against Aß1-40 at 3 µM and 10 µM concentrations. Consequently, KT2d is a potential new hit-ligand for AD therapy for further biological exploration.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores da Colinesterase/farmacologia , Fármacos Neuroprotetores/farmacologia , Tacrina/farmacologia , Acetilcolinesterase/metabolismo , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Relação Dose-Resposta a Droga , Desenho de Fármacos , Humanos , Modelos Moleculares , Estrutura Molecular , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química , Relação Estrutura-Atividade , Tacrina/síntese química , Tacrina/químicaRESUMO
Alzheimer's disease (AD) is a progressive neurodegenerative disorder and currently there is no efficient treatment. The classic drug-design strategy based on the "one-molecule-one-target" paradigm was found to be ineffective in the case of multifactorial diseases like AD. A novel multi-target-directed ligand strategy based on the assumption that a single compound consisting of two or more distinct pharmacophores is able to hit multiple targets has been proposed as promising. Herein, we investigated 7-methoxytacrine - memantine heterodimers developed with respect to the multi-target-directed ligand theory. The spectroscopic, microscopic and cell culture methods were used for systematic investigation of the interference of the heterodimers with ß-secretase (BACE1) activity, Aß peptide amyloid fibrillization (amyloid theory) and interaction with M1 subtype of muscarinic (mAChRs), nicotinic (nAChRs) acetylcholine receptors (cholinergic theory) and N-methyl-d-aspartate receptors (NMDA) (glutamatergic theory). The drug-like properties of selected compounds have been evaluated from the point of view of blood-brain barrier penetration and cell proliferation. We have confirmed the multipotent effect of novel series of compounds. They inhibited effectively Aß peptide amyloid fibrillization and affected the BACE1 activity. Moreover, they have AChE inhibitory potency but they could not potentiate cholinergic transmission via direct interaction with cholinergic receptors. All compounds were reported to act as an antagonist of both M1 muscarinic and muscle-type nicotinic receptors. We have found that 7-methoxytacrine - memantine heterodimers are able to hit multiple targets associated with Alzheimer's disease and thus, have a potential clinical impact for slowing or blocking the neurodegenerative process related to this disease.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Amantadina/farmacologia , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Tacrina/análogos & derivados , Doença de Alzheimer/metabolismo , Amantadina/análogos & derivados , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Células CHO , Colinesterases/metabolismo , Cricetulus , Dimerização , Inibidores Enzimáticos/química , Células HEK293 , Humanos , Terapia de Alvo Molecular , Receptor Muscarínico M1/antagonistas & inibidores , Receptor Muscarínico M1/metabolismo , Receptores Colinérgicos/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Tacrina/química , Tacrina/farmacologia , XenopusRESUMO
The ability of two newly developed oximes (K305, K307) to protect tabun-poisoned rats from tabun-induced inhibition of brain acetylcholinesterase, acute neurotoxic signs and symptoms and brain damage was compared with that of the oxime K203 and trimedoxime. The reactivating and neuroprotective effects of the oximes studied combined with atropine on rats poisoned with tabun at a sublethal dose were evaluated. The reactivating efficacy of a newly developed oxime K305 is lower compared to the reactivating efficacy of the oxime K203 and trimedoxime while the ability of the oxime K307 to reactivate tabun-inhibited acetylcholinesterase (AChE) in the brain roughly corresponds to the reactivating efficacy of the oxime K203 and it is slightly lower compared to trimedoxime. In addition, only one newly developed oxime (K307) combined with atropine was able to markedly decrease tabun-induced neurotoxicity although it did not eliminate all tabun-induced acute neurotoxic signs and symptoms. These results correspond to the histopathological evaluation of tabun-induced brain damage. Therefore, the newly developed oximes are not suitable for the replacement of commonly used oximes (especially trimedoxime) in the treatment of acute tabun poisonings.
Assuntos
Substâncias para a Guerra Química/intoxicação , Reativadores da Colinesterase/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Intoxicação por Organofosfatos/tratamento farmacológico , Organofosfatos/toxicidade , Oximas/uso terapêutico , Compostos de Piridínio/uso terapêutico , Acetilcolinesterase/metabolismo , Animais , Atropina/uso terapêutico , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Humanos , Masculino , Síndromes Neurotóxicas/tratamento farmacológico , Ratos Wistar , Trimedoxima/uso terapêuticoRESUMO
A novel series of 6-chlorotacrine-scutellarin hybrids was designed, synthesized and the biological activity as potential anti-Alzheimer's agents was assessed. Their inhibitory activity towards human acetylcholinesterase (hAChE) and human butyrylcholinesterase (hBChE), antioxidant activity, ability to cross the blood-brain barrier (BBB) and hepatotoxic profile were evaluated in vitro. Among these compounds, hybrid K1383, bearing two methylene tether between two basic scaffolds, was found to be very potent hAChE inhibitor (IC50 = 1.63 nM). Unfortunately, none of the hybrids displayed any antioxidant activity (EC50 ≥ 500 µM). Preliminary data also suggests a comparable hepatotoxic profile with 6-Cl-THA (established on a HepG2 cell line). Kinetic studies performed on hAChE with the most active compound in the study, K1383, pointed out to a mixed, non-competitive enzyme inhibition. These findings were further corroborated by docking studies.
Assuntos
Apigenina/química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Glucuronatos/química , Tacrina/análogos & derivados , Acetilcolinesterase/metabolismo , Doença de Alzheimer/enzimologia , Barreira Hematoencefálica/metabolismo , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/síntese química , Desenho de Fármacos , Ativação Enzimática/efeitos dos fármacos , Humanos , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade , Tacrina/químicaRESUMO
Tacrine (THA), the first clinically effective acetylcholinesterase (AChE) inhibitor and the first approved drug for the treatment of Alzheimer's disease (AD), was withdrawn from the market due to its side effects, particularly its hepatotoxicity. Nowadays, THA serves as a valuable scaffold for the design of novel agents potentially applicable for AD treatment. One such compound, namely 7-methoxytacrine (7-MEOTA), exhibits an intriguing profile, having suppressed hepatotoxicity and concomitantly retaining AChE inhibition properties. Another interesting class of AChE inhibitors represents Huprines, designed by merging two fragments of the known AChE inhibitors-THA and (-)-huperzine A. Several members of this compound family are more potent human AChE inhibitors than the parent compounds. The most promising are so-called huprines X and Y. Here, we report the design, synthesis, biological evaluation, and in silico studies of 2-methoxyhuprine that amalgamates structural features of 7-MEOTA and huprine Y in one molecule.
Assuntos
Aminoquinolinas/química , Aminoquinolinas/farmacologia , Descoberta de Drogas , Acetilcolinesterase , Doença de Alzheimer/tratamento farmacológico , Aminoquinolinas/síntese química , Sítios de Ligação , Barreira Hematoencefálica/metabolismo , Butirilcolinesterase , Domínio Catalítico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Desenho de Fármacos , Ativação Enzimática/efeitos dos fármacos , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Humanos , Hidrólise , Concentração Inibidora 50 , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Permeabilidade , Ligação Proteica , Relação Estrutura-Atividade , Tacrina/análogos & derivados , Tacrina/química , Tacrina/farmacologiaRESUMO
Organophosphorus nerve agents inhibit acetylcholinesterase (AChE) which causes the breakdown of the transmitter acetylcholine (ACh) in the synaptic cleft. Overstimulation of cholinergic receptors (muscarinic and nicotinic) by excessive amounts of ACh causes several health problems and may even cause death. Reversible AChE inhibitors play an important role in prophylaxis against nerve agents. The presented study investigated whether 7-methoxytacrine (7-MEOTA) and 7-MEOTA-donepezil derivatives can act as central and peripheral reversible AChE inhibitors and simultaneously antagonize muscarinic and nicotinic receptors. The possible mechanism of action was studied on cell cultures (patch clamp technique, calcium mobilization assay) and on isolated smooth muscle tissue (contraction study). Furthermore, the kinetics of the compounds were also examined. CNS availability was predicted by determining the passive blood-brain barrier penetration estimated via a modified PAMPA assay. In conclusion, this study provides promising evidence that the new synthesized 7-MEOTA-donepezil derivatives have the desired anticholinergic effect; they can inhibit AChE, and nicotinic and muscarinic receptors in the micromolar range. Furthermore, they seem to penetrate readily into the CNS. However, their real potency and benefit must be verified by in vivo experiments.
Assuntos
Antagonistas Colinérgicos/administração & dosagem , Indanos/administração & dosagem , Antagonistas Muscarínicos/administração & dosagem , Fibras Musculares Esqueléticas/metabolismo , Antagonistas Nicotínicos/administração & dosagem , Piperidinas/administração & dosagem , Tacrina/análogos & derivados , Animais , Células Cultivadas , Donepezila , Relação Dose-Resposta a Droga , Masculino , Fibras Musculares Esqueléticas/efeitos dos fármacos , Ratos , Ratos Wistar , Tacrina/administração & dosagemRESUMO
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.
Assuntos
Acetilcolinesterase/química , Peptídeos beta-Amiloides/antagonistas & inibidores , Compostos de Anilina/química , Fármacos do Sistema Nervoso Central/química , Inibidores da Colinesterase/química , Tacrina/análogos & derivados , Peptídeos beta-Amiloides/química , Compostos de Anilina/síntese química , Sítios de Ligação , Fármacos do Sistema Nervoso Central/síntese química , Inibidores da Colinesterase/síntese química , Humanos , Cinética , Simulação de Acoplamento Molecular , Proteínas Recombinantes/química , Relação Estrutura-AtividadeRESUMO
The ability of two novel bispyridinium oximes K727 and K733 and currently available oximes (HI-6, obidoxime) to reactivate sarin-inhibited acetylcholinesterase and to reduce acute toxicity of sarin was evaluated. To investigate the reactivating efficacy of the oximes, the rats were administered intramuscularly with atropine and oximes in equitoxic doses corresponding to 5% of their LD50 values at 1 min after the intramuscular administration of sarin at a dose of 24 µg/kg (LD50). The activity of acetylcholinesterase was measured at 60 min after sarin poisoning. The LD50 value of sarin in non-treated and treated mice was assessed using probit-logarithmical analysis of death occurring within 24 h after intramuscular administration of sarin at five different doses. In vivo determined percentage of reactivation of sarin-inhibited rat blood, diaphragm and brain acetylcholinesterase showed that the potency of both novel oximes K727 and K733 to reactivate sarin-inhibited acetylcholinesterase roughly corresponds to the reactivating efficacy of obidoxime. On the other hand, the oxime HI-6 was found to be the most efficient reactivator of sarin-inhibited acetylcholinesterase. While the oxime HI-6 was able to reduce the acute toxicity of sarin >3 times, both novel oximes and obidoxime decreased the acute toxicity of sarin <2 times. Based on the results, we can conclude that the reactivating and therapeutic efficacy of both novel oximes K727 and K733 is significantly lower compared to the oxime HI-6 and, therefore, they are not suitable for the replacement of the oxime HI-6 for the antidotal treatment of acute sarin poisoning.
Assuntos
Antídotos/uso terapêutico , Inibidores da Colinesterase/toxicidade , Reativadores da Colinesterase/uso terapêutico , Síndromes Neurotóxicas/tratamento farmacológico , Oximas/uso terapêutico , Compostos de Piridínio/uso terapêutico , Sarina/toxicidade , Acetilcolinesterase/sangue , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Animais , Animais não Endogâmicos , Atropina/uso terapêutico , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Inibidores da Colinesterase/administração & dosagem , Inibidores da Colinesterase/química , Diafragma/efeitos dos fármacos , Diafragma/enzimologia , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Masculino , Camundongos , Antagonistas Muscarínicos/uso terapêutico , Proteínas do Tecido Nervoso/agonistas , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/enzimologia , Síndromes Neurotóxicas/sangue , Síndromes Neurotóxicas/etiologia , Síndromes Neurotóxicas/metabolismo , Cloreto de Obidoxima/uso terapêutico , Ratos Wistar , Sarina/administração & dosagem , Sarina/antagonistas & inibidoresRESUMO
The potency of two newly developed oximes (K361 and K378) to reactivate tabun-inhibited cholinesterase and to reduce acute toxicity of tabun was compared with the oxime K203 and trimedoxime using in vivo methods. The study determining percentage of reactivation of tabun-inhibited diaphragm cholinesterase in poisoned rats showed that the reactivating efficacy of the oxime K378 is slightly lower than the reactivating potency of the oxime K203 and trimedoxime while the ability of the oxime K361 to reactivate tabun-inhibited cholinesterase is markedly lower compared with the oxime K203 and trimedoxime. In the brain, the potency of both newly developed oximes to reactivate tabun-inhibited cholinesterase was negligible. The therapeutic efficacy of both newly developed oximes roughly corresponds to their weak reactivating efficacy. Their potency to reduce acute toxicity of tabun was significantly lower compared with the oxime K203 as well as trimedoxime. In conclusion, the reactivating and therapeutic potency of both newly developed oximes does not prevail the effectiveness of the oxime K203 and trimedoxime and, therefore, they are not suitable for their replacement of commonly used oximes for the treatment of acute tabun poisoning.
Assuntos
Inibidores da Colinesterase/intoxicação , Reativadores da Colinesterase/uso terapêutico , Organofosfatos/toxicidade , Oximas/uso terapêutico , Compostos de Piridínio/uso terapêutico , Trimedoxima/uso terapêutico , Animais , Barreira Hematoencefálica , Masculino , Camundongos , Ratos Wistar , Relação Estrutura-AtividadeRESUMO
The ability of a novel bispyridinium oxime K203 to reactivate VX agent-inhibited acetylcholinesterase was compared with the reactivating efficacy of four commonly used oximes (obidoxime, trimedoxime, methoxime, HI-6) using in vivo model. Our results showed that the reactivating efficacy of the oxime HI-6 is higher than the reactivating efficacy of the other oximes studied including the oxime K203 although the differrences between the oxime HI-6 and some other oximes are not significant, especially in the blood. Based on the obtained data, we can conclude that the antidotal treatment involving the oxime HI-6 brings the higher benefit for the antidotal treatment of acute poisonings with VX agent than other oximes.
Assuntos
Acetilcolinesterase/metabolismo , Compostos Organotiofosforados/antagonistas & inibidores , Oximas/farmacologia , Animais , Relação Dose-Resposta a Droga , Masculino , Estrutura Molecular , Compostos Organotiofosforados/farmacologia , Compostos Organotiofosforados/toxicidade , Oximas/química , Ratos , Ratos Wistar , Relação Estrutura-AtividadeRESUMO
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.
Assuntos
Sistema Nervoso Central/efeitos dos fármacos , Reativadores da Colinesterase , Junção Neuromuscular/efeitos dos fármacos , Albumina Sérica/metabolismo , Acetilcolina/metabolismo , Acetilcolinesterase/metabolismo , Adsorção , Animais , Domínio Catalítico , Reativadores da Colinesterase/sangue , Reativadores da Colinesterase/metabolismo , Reativadores da Colinesterase/farmacocinética , Masculino , Junção Neuromuscular/metabolismo , Organofosfatos/química , Organofosfatos/metabolismo , Ligação Proteica , Ratos , Ratos WistarRESUMO
Acetylcholinesterase (AChE) reactivators were developed for the treatment of organophosphate intoxication. Standard care involves the use of anticonvulsants (e.g., diazepam), parasympatolytics (e.g., atropine) and oximes that restore AChE activity. However, oximes also bind to the active site of AChE, simultaneously acting as reversible inhibitors. The goal of the present study is to determine how oxime structure influences the inhibition of human recombinant AChE (hrAChE). Therefore, 24 structurally different oximes were tested and the results compared to the previous eel AChE (EeAChE) experiments. Structural factors that were tested included the number of pyridinium rings, the length and structural features of the linker, and the number and position of the oxime group on the pyridinium ring.
Assuntos
Acetilcolinesterase/química , Inibidores da Colinesterase/química , Oximas/química , Domínio Catalítico , Humanos , Ligação de Hidrogênio , Simulação de Acoplamento Molecular , Ligação Proteica , Relação Estrutura-AtividadeRESUMO
The potency of three newly developed bispyridinium compounds (K454, K456, K458) to reactivate tabun-inhibited acetylcholinesterase and reduce tabun-induced lethal toxic effects was compared with the oxime K203 and trimedoxime using in vivo methods. The study determining percentage of reactivation of tabun-inhibited diaphragm and brain acetylcholinesterase in poisoned rats showed that the reactivating efficacy of all newly developed oximes is comparable with K203 but lower than the reactivating potency of trimedoxime in diaphragm. In the brain, their potency to reactivate tabun-inhibited acetylcholinesterase is lower compared with trimedoxime and the oxime K203. All three newly developed oximes were also found to be relatively effective in reducing lethal toxic effects in tabun-poisoned mice. Their therapeutic efficacy is consistent with the therapeutic potency of the oxime K203. On the other hand, their potency to reduce acute toxicity of tabun is significantly lower compared with trimedoxime. In conclusion, the reactivating and therapeutic potency of all three newly developed oximes does not prevail the effectiveness of the oxime K203 and trimedoxime and, therefore, they are not suitable for their replacement of commonly used oximes for the treatment of acute tabun poisoning.
Assuntos
Substâncias para a Guerra Química/intoxicação , Inibidores da Colinesterase/toxicidade , Reativadores da Colinesterase/toxicidade , Organofosfatos/toxicidade , Compostos de Piridínio/toxicidade , Trimedoxima/toxicidade , Acetilcolinesterase/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Diafragma/efeitos dos fármacos , Diafragma/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos , Ratos , Ratos WistarRESUMO
The ability of 2 combinations of oximes (HI-6 + trimedoxime and HI-6 + K203) to reactivate VX-inhibited acetylcholinesterase and reduce acute toxicity of VX was compared with the reactivating and therapeutic efficacy of antidotal treatment involving a single oxime (HI-6, trimedoxime, K203) in rats and mice. Our results showed that the reactivating efficacy of both combinations of oximes studied in rats is significantly higher than the reactivating efficacy of all individual oximes in diaphragm and roughly corresponds to the most effective individual oxime in blood and brain. Both combinations of oximes were found to be more effective in the reduction of acute lethal toxicity of VX in mice than the antidotal treatment involving the most efficacious individual oxime although the difference is not significant. Based on the obtained data, we can conclude that the antidotal treatment involving the chosen combinations of oximes brings benefit for the reactivation of VX-inhibited acetylcholinesterase in rats and for the antidotal treatment of VX-induced acute poisoning in mice.
Assuntos
Acetilcolinesterase/efeitos dos fármacos , Antídotos/farmacologia , Compostos Organotiofosforados/toxicidade , Oximas/farmacologia , Compostos de Piridínio/farmacologia , Trimedoxima/farmacologia , Acetilcolinesterase/metabolismo , Animais , Atropina/farmacologia , Encéfalo/efeitos dos fármacos , Inibidores da Colinesterase/metabolismo , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Dose Letal Mediana , Masculino , Camundongos , Ratos , Ratos WistarRESUMO
BACKGROUND: The design of new heterodimeric dual binding site acetylcholinesterase inhibitors constitutes the main goal-directed to the development of new anticholinesterase agents with the expanded pharmacological profile. Multi-target compounds are usually designed by combining in a hybrid molecule with two or more pharmacophoric moieties that are known to enable interaction with the selected molecular targets. METHODS: All compounds were tested for their inhibitory activity on human AChE/BChE. The Ellman´s method was used to determine inhibition kinetics and IC50 values. In order to predict passive bloodbrain penetration of novel compounds, modification of the parallel artificial membrane permeation assay has been used. Docking studies were performed in order to predict the binding modes of new hybrids with hAChE/ hBChE respectively. RESULTS: In this study, we described the design, synthesis, and evaluation of series tacrine-coumarin and tacrine-quinoline compounds which were found to show potential inhibition of ChEs and penetration of the blood-brain barrier. CONCLUSION: Tacrine-quinoline hybrids 7a exhibited the highest activity towards hBChE (IC50 = 0.97 µmol) and 7d towards hAChE (IC50 = 0.32 µmol). Kinetic and molecular modelling studies revealed that 7d was a mixed-type AChE inhibitor (Ki = 1.69 µmol) and 7a was a mixed-type BChE inhibitor (Ki = 1.09 µmol). Moreover, hybrid 5d and 7c could penetrate the CNS.
Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Inibidores da Colinesterase/farmacologia , Cumarínicos/farmacologia , Tacrina/farmacologia , Tioureia/farmacologia , Animais , Inibidores da Colinesterase/química , Cumarínicos/química , Humanos , Cinética , Modelos Moleculares , Simulação de Acoplamento Molecular , Permeabilidade/efeitos dos fármacos , Relação Estrutura-Atividade , Tacrina/química , Tioureia/químicaRESUMO
BACKGROUND: Intoxication by nerve agents could be prevented by using small acetylcholinesterase inhibitors (eg, pyridostigmine) for potentially exposed personnel. However, the serious side effects of currently used drugs led to research of novel potent molecules for prophylaxis of organophosphorus intoxication. METHODS: The molecular design, molecular docking, chemical synthesis, in vitro methods (enzyme inhibition, cytotoxicity, and nicotinic receptors modulation), and in vivo methods (acute toxicity and prophylactic effect) were used to study bispyridinium, bisquinolinium, bisisoquinolinium, and pyridinium-quinolinium/isoquinolinium molecules presented in this study. RESULTS: The studied molecules showed non-competitive inhibitory ability towards human acetylcholinesterase in vitro that was further confirmed by molecular modelling studies. Several compounds were selected for further studies. First, their cytotoxicity, nicotinic receptors modulation, and acute toxicity (lethal dose for 50% of laboratory animals [LD50]; mice and rats) were tested to evaluate their safety with promising results. Furthermore, their blood levels were measured to select the appropriate time for prophylactic administration. Finally, the protective ratio of selected compounds against soman-induced toxicity was determined when selected compounds were found similarly potent or only slightly better to standard pyridostigmine. CONCLUSION: The presented small bisquaternary molecules did not show overall benefit in prophylaxis of soman-induced in vivo toxicity.
Assuntos
Inibidores da Colinesterase/farmacologia , Agentes Neurotóxicos/efeitos adversos , Bibliotecas de Moléculas Pequenas/farmacologia , Acetilcolinesterase/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Inibidores da Colinesterase/química , Relação Dose-Resposta a Droga , Células HeLa , Humanos , Modelos Moleculares , Estrutura Molecular , Bibliotecas de Moléculas Pequenas/química , Soman/efeitos adversos , Relação Estrutura-AtividadeRESUMO
The multitarget approach is a promising paradigm in drug discovery, potentially leading to new treatment options for complex disorders, such as Alzheimer's disease. Herein, we present the discovery of a unique series of 1-benzylamino-2-hydroxyalkyl derivatives combining inhibitory activity against butyrylcholinesterase, ß-secretase, ß-amyloid, and tau protein aggregation, all related to mechanisms which underpin Alzheimer's disease. Notably, diphenylpropylamine derivative 10 showed balanced activity against both disease-modifying targets, inhibition of ß-secretase (IC50 hBACE-1 = 41.60 µM), inhibition of amyloid ß aggregation (IC50 Aß = 3.09 µM), inhibition of tau aggregation (55% at 10 µM); as well as against symptomatic targets, butyrylcholinesterase inhibition (IC50 hBuChE = 7.22 µM). It might represent an encouraging starting point for development of multifunctional disease-modifying anti-Alzheimer's agents.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Butirilcolinesterase/farmacologia , Inibidores da Colinesterase/farmacologia , Desenho de Fármacos , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/efeitos dos fármacos , Peptídeos beta-Amiloides/metabolismo , Humanos , Simulação de Acoplamento Molecular/métodos , Fragmentos de Peptídeos/metabolismo , Relação Estrutura-Atividade , Proteínas tau/efeitos dos fármacosRESUMO
Multi-target drug discovery is one of the most followed approaches in the active central nervous system (CNS) therapeutic area, especially in the search for new drugs against Alzheimer's disease (AD). This is because innovative multi-target-directed ligands (MTDLs) could more adequately address the complexity of this pathological condition. In a continuation of our efforts aimed at a new series of anti-AD MTDLs, we combined the structural features of the cholinesterase inhibitor drug tacrine with that of resveratrol, which is known for its purported antioxidant and anti-neuroinflammatory activities. The most interesting hybrid compounds (5, 8, 9 and 12) inhibited human acetylcholinesterase at micromolar concentrations and effectively modulated Aß self-aggregation in vitro. In addition, 12 showed intriguing anti-inflammatory and immuno-modulatory properties in neuronal and glial AD cell models. Importantly, the MTDL profile is accompanied by high-predicted blood-brain barrier permeability, and low cytotoxicity on primary neurons.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Desenho de Fármacos , Terapia de Alvo Molecular , Estilbenos/química , Tacrina/química , Tacrina/farmacologia , Acetilcolinesterase/metabolismo , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/química , Animais , Antioxidantes/química , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Barreira Hematoencefálica/metabolismo , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/química , Inibidores da Colinesterase/metabolismo , Inibidores da Colinesterase/farmacologia , Inibidores da Colinesterase/uso terapêutico , Humanos , Ligantes , Fígado/efeitos dos fármacos , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Fragmentos de Peptídeos/química , Agregados Proteicos/efeitos dos fármacos , Ratos , Resveratrol , Tacrina/metabolismo , Tacrina/uso terapêuticoRESUMO
Novel indolotacrine analogues were designed, synthesized, and evaluated as potential drugs for the treatment of Alzheimer's disease. By using a multitarget-directed ligand approach, compounds were designed to act simultaneously as cholinesterase (ChE) and monoamine oxidase (MAO) inhibitors. The compounds were also evaluated for antioxidant, cytotoxic, hepatotoxic, and blood-brain barrier (BBB) permeability properties. Indolotacrine 9 b (9-methoxy-2,3,4,6-tetrahydro-1H-indolo[2,3-b]quinolin-11-amine) showed the most promising results in the in vitro assessment; it is a potent inhibitor of acetylcholinesterase (AChE IC50 : 1.5â µm), butyrylcholinesterase (BChE IC50 : 2.4â µm) and MAOâ A (IC50 : 0.49â µm), and it is also a weak inhibitor of MAOâ B (IC50 : 53.9â µm). Although its cytotoxic (IC50 : 5.5±0.4â µm) and hepatotoxic (IC50 : 1.22±0.11â µm) profiles are not as good as those of the standard 7-methoxytacrine (IC50 : 63±4 and 11.50±0.77â µm, respectively), the overall improvement in the inhibitory activities and potential to cross the BBB make indolotacrine 9 b a promising lead compound for further development and investigation.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores da Colinesterase/uso terapêutico , Desenho de Fármacos , Indóis/síntese química , Inibidores da Monoaminoxidase/uso terapêutico , Quinolinas/síntese química , Tacrina/química , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Barreira Hematoencefálica/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/metabolismo , Inibidores da Colinesterase/toxicidade , Células Hep G2 , Humanos , Indóis/química , Indóis/metabolismo , Indóis/uso terapêutico , Indóis/toxicidade , Concentração Inibidora 50 , Ligantes , Monoaminoxidase/química , Monoaminoxidase/metabolismo , Inibidores da Monoaminoxidase/síntese química , Inibidores da Monoaminoxidase/metabolismo , Inibidores da Monoaminoxidase/toxicidade , Quinolinas/química , Quinolinas/metabolismo , Quinolinas/uso terapêutico , Quinolinas/toxicidade , Relação Estrutura-Atividade , Tacrina/metabolismo , Tacrina/uso terapêutico , Tacrina/toxicidadeRESUMO
Alzheimer's disease is a multifactorial disease that is characterized mainly by Amyloid-ß (A-ß) deposits, cholinergic deficit and extensive metal (copper, iron)-induced oxidative stress. In this work we present details of the synthesis, antioxidant and copper-chelating properties, DNA protection study, cholinergic activity and amyloid-antiaggregation properties of new multifunctional tacrine-7-hydroxycoumarin hybrids. The mode of interaction between copper(II) and hybrids and interestingly, the reduction of Cu(II) to Cu(I) species (for complexes Cu-5e-g) were confirmed by EPR measurements. EPR spin trapping on the model Fenton reaction, using 5,5-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trap, demonstrated a significantly suppressed formation of hydroxyl radicals for the Cu-5e complex in comparison with free copper(II). This suggests that compound 5e upon coordination to free copper ion prevents the Cu(II)-catalyzed decomposition of hydrogen peroxide, which in turn may alleviate oxidative stress-induced damage. Protective activity of hybrids 5c and 5e against DNA damage in a Fenton system (copper catalyzed) was found to be in excellent agreement with the EPR spin trapping study. Compound 5g was the most effective in the inhibition of acetylcholinesterase (hAChE, IC50=38nM) and compound 5b was the most potent inhibitor of butyrylcholinesterase (hBuChE, IC50=63nM). Compound 5c was the strongest inhibitor of A-ß1-40 aggregation, although a significant inhibition (>50%) was detected for compounds 5b, 5d, 5e and 5g. Collectively, these results suggest that the design and investigation of multifunctional agents containing along with the acetylcholinesterase inhibitory segment also an antioxidant moiety capable of alleviating metal (copper)-induced oxidative stress, may be of importance in the treatment of Alzheimer's disease.