RESUMO
Resveratrol (3,5,4'-trihydroxy-trans-stilbene), a phenol commonly found in grapes and wine, has been associated as protective in experimental models involving alterations in different neurotransmitter systems. However, studies are reporting that resveratrol could have adverse effects. This study evaluated if the association of a low dose of ketamine and resveratrol could induce behavioral manifestations associated with biochemical alterations. Moreover, the effects of treatment with resveratrol and/or ketamine on monoamine oxidase (MAO) activity, oxidative stress markers, and IL-6 levels in the brain were also investigated. Male Swiss mice received a low dose of ketamine (20 mg/kg) for 14 consecutive days, and resveratrol (10, 30, or 100 mg/kg) from day 8 up to day 14 of the experimental period, intraperitoneally. Locomotor, stereotyped behavior, Y-maze, novel recognition object test (NORT), and social interaction were quantified as well as ex vivo analysis of MAO activity, IL-6 levels, and oxidative stress markers (TBARS and total thiol levels) in brain tissues. Ketamine per se reduced the number of bouts of stereotyped behavior on day 8 of the experimental period. Resveratrol per se reduced the locomotor and exploratory activity in the open field, the time of exploration of new objects in the NORT, MAO-A activity in the striatum and increased the IL-6 levels in the cortex. These effects were attenuated when the mice were co-treated with ketamine and resveratrol. There was a decrease in MAO-A activity in the cortex of mice treated with ketamine + resveratrol 100 mg/kg. No significant alterations were found in oxidative stress markers. Resveratrol does not appear to cause summative effects with ketamine on behavioral alterations. However, the effect of resveratrol per se, mainly on locomotor and exploratory activity, should be better investigated.
Assuntos
Ketamina , Monoaminoxidase , Estresse Oxidativo , Resveratrol , Animais , Resveratrol/farmacologia , Resveratrol/administração & dosagem , Ketamina/farmacologia , Masculino , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Monoaminoxidase/metabolismo , Monoaminoxidase/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Comportamento Exploratório/efeitos dos fármacos , Interleucina-6/metabolismo , Comportamento Estereotipado/efeitos dos fármacos , Antagonistas de Aminoácidos Excitatórios/farmacologia , Antagonistas de Aminoácidos Excitatórios/administração & dosagem , Interação Social/efeitos dos fármacos , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Reconhecimento Psicológico/efeitos dos fármacos , Atividade Motora/efeitos dos fármacosRESUMO
1-(Phenylselanyl)-2-(p-tolyl)indolizine (MeSeI) is a selenoindolizine with an antidepressant-like effect in mice by regulation of the serotonergic system. This study investigated the involvement of dopaminergic and noradrenergic systems in the antidepressant-like action of MeSeI. For this purpose, Swiss male mice were pretreated with different antagonists, after 15 min, the MeSeI was administrated by intragastric (i.g.) via; after 30 min, the mouse behavior was assessed in the forced swimming test (FST). The action of MeSeI on the activity of monoamine oxidase (MAO) was determined. The pretreatment of mice with haloperidol (0.05 mg/kg, intraperitoneally, i.p.; non-selective dopamine receptor antagonist), sulpiride (50 mg/kg, i.p.; D2 receptor antagonist), yohimbine (1 mg/kg, i.p.; α2 receptor antagonist), and propranolol (2 mg/kg, i.p.; non-selective ß receptor antagonist), inhibited the anti-immobility action of MeSeI (50 mg/kg, i.g.) in the FST. This blocking effect was not observed when SCH23390 (0.01 mg/kg, i.p.; D1 receptor antagonist), and prazosin (1 mg/kg, i.p.; α1 receptor antagonist) were administered. The coadministration of subeffective doses of bupropion (3 mg/kg. i.g.; dopamine and noradrenaline reuptake inhibitor) and MeSeI (0.5 mg/kg. i.g.) reduced the immobility time in the FST. Furthermore, MeSeI inhibited MAO-A and B activities in vitro and ex vivo tests. These results suggest that MeSeI exerts its antidepressant-like effect via regulation of the D2, α2, and ß1 receptors and the inhibition of MAO-A and B activities. Molecular docking investigations corroborated these results. This study provides comprehensive insights into the antidepressant-like mechanism of MeSeI in mice, suggesting its potential as a novel antidepressant candidate.
Assuntos
Antidepressivos , Dopamina , Monoaminoxidase , Compostos Organosselênicos , Animais , Masculino , Camundongos , Antidepressivos/farmacologia , Compostos Organosselênicos/farmacologia , Monoaminoxidase/metabolismo , Monoaminoxidase/efeitos dos fármacos , Dopamina/metabolismo , Antagonistas de Dopamina/farmacologia , Natação , Norepinefrina/metabolismo , Receptores Dopaminérgicos/metabolismo , Receptores Dopaminérgicos/efeitos dos fármacos , Depressão/tratamento farmacológico , Depressão/metabolismo , Atividade Motora/efeitos dos fármacosRESUMO
Monoamine oxidases (MAOs) are attractive targets in drug design. The inhibition of one of the isoforms (A or B) is responsible for modulating the levels of different neurotransmitters in the central nervous system, as well as the production of reactive oxygen species. Molecules that act selectively on one of the MAO isoforms have been studied deeply, and coumarin has been described as a promising scaffold. In the current manuscript we describe a comparative study between 3-phenylcoumarin (endo coumarin-resveratrol-inspired hybrid) and trans-6-styrylcoumarin (exo coumarin-resveratrol-inspired hybrid). Crystallographic structures of both compounds were obtained and analyzed. 3D-QSAR models, in particular CoMFA and CoMSIA, docking simulations and molecular dynamics simulations have been performed to support and better understand the interaction of these molecules with both MAO isoforms. Both molecules proved to inhibit MAO-B, with trans-6-styrylcoumarin being 107 times more active than 3-phenylcoumarin, and 267 times more active than trans-resveratrol.
Assuntos
Cumarínicos/química , Inibidores da Monoaminoxidase/farmacologia , Monoaminoxidase/efeitos dos fármacos , Resveratrol/química , Estirenos/química , Domínio Catalítico , Simulação de Acoplamento MolecularRESUMO
Monoamine oxidase B inhibitory activity is closely regulated by the interaction of the small molecules with the enzyme. It is therefore desirable to use theoretical approaches to design rational methods to develop new molecules to modulate specific interactions with the protein. Here, we report such methods, and we illustrate their successful implementation by studying six synthetized 3-arylcoumarins (71-76) based on them. Monoamine oxidase B inhibition is essential to maintain the balance of dopamine, and one of its major functions is to combat dopamine degradation, a phenomenon linked to Parkinson's disease. In this work, we study small-molecule inhibitors based on the 3-arylcoumarin scaffold and their monoamine oxidase B selective inhibition. We show that 3D-QSAR models, in particular CoMFA and CoMSIA, and molecular docking approaches, enhance the probability to find new interesting inhibitors, avoiding very costly and time-consuming synthesis and biological evaluations.
Assuntos
Cumarínicos/farmacologia , Inibidores da Monoaminoxidase/farmacologia , Monoaminoxidase/efeitos dos fármacos , Cumarínicos/química , Descoberta de Drogas , Humanos , Inibidores da Monoaminoxidase/química , Relação Quantitativa Estrutura-AtividadeRESUMO
Despite recent advances, current antidepressants have considerable limitations: late onset of action and the high profile of refractoriness. Biomedical research with natural products has gained growing interest in the last years, and had provide useful candidates for new antidepressants. Riparins are a group of natural alkamides obtained from Aniba riparia, which had marked neuroactive effects, mainly as antidepressant and antinociceptive agents. We made modifications of the basic structure of riparins, originating a synthetic alkamide, also known as riparin IV (RipIV). RipIV demonstrated a superior analgesic effect than its congeners and a marked antidepressant-like effect. However, the basic mechanism for the central effects of RipIV remains unknown. Here, we aimed to investigate the participation of monoaminergic neurotransmission targets in the antidepressant-like effects of RipIV. To do this, we applied a combined approach of experimental (classical pharmacology and neurochemistry) and computer-aided techniques. Our results demonstrated that RipIV presented antidepressant- and anxiolytic-like effects without modifying locomotion and motor coordination of mice. Also, RipIV increased brain monoamines and their metabolite levels. At the higher dose (100â¯mg/kg), RipIV increased serotonin concentrations in all studied brain areas, while at the lower one (50â¯mg/kg), it increased mainly dopamine and noradrenaline levels. When tested with selective receptor antagonists, RipIV antidepressant effect showed dependence of the activation of multiple targets, including D1 and D2 dopamine receptors, 5-HT2A/2, 5-HT3 receptors and α2 adrenergic receptors. Molecular docking demonstrated favorable binding conformation and affinity of RipIV to monoamine oxidase B (MAO-B), serotonin transporter (SERT), α1 receptor, D2 receptor, dopamine transporter (DAT) and at some extent GABA-A receptor. RipIV also presented a computationally predicted favorable pharmacokinetic profile. Therefore, this study demonstrated the involvement of monoaminergic targets in the mechanism of RipIV antidepressant-like action, and provide evidence of it as a promising new antidepressant.
Assuntos
Ansiolíticos/farmacologia , Antidepressivos/farmacologia , Monoaminoxidase/efeitos dos fármacos , Receptores Adrenérgicos alfa 2/efeitos dos fármacos , Receptores Dopaminérgicos/efeitos dos fármacos , Receptores de Serotonina/efeitos dos fármacos , Tiramina/análogos & derivados , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Bupropiona/farmacologia , Dopamina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/efeitos dos fármacos , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Fluoxetina/farmacologia , Imipramina/farmacologia , Camundongos , Simulação de Acoplamento Molecular , Monoaminoxidase/metabolismo , Norepinefrina/metabolismo , Receptor 5-HT2A de Serotonina/efeitos dos fármacos , Receptor 5-HT2A de Serotonina/metabolismo , Receptores Adrenérgicos alfa 2/metabolismo , Receptores Dopaminérgicos/metabolismo , Receptores de Dopamina D1 , Receptores de Dopamina D2 , Receptores de GABA-A/efeitos dos fármacos , Receptores de GABA-A/metabolismo , Receptores de Serotonina/metabolismo , Receptores 5-HT2 de Serotonina/efeitos dos fármacos , Receptores 5-HT2 de Serotonina/metabolismo , Receptores 5-HT3 de Serotonina/efeitos dos fármacos , Receptores 5-HT3 de Serotonina/metabolismo , Serotonina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/efeitos dos fármacos , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Tiramina/farmacologiaRESUMO
Alzheimer's disease (AD) is the most common cause of dementia, characterized by loss of selective neuronal and normal brain functions. Every year, ten million new cases are diagnosed worldwide. AD is a complex disease associated with all kind of different pathways, making their simultaneous modulation necessary. Nowadays anti-AD treatments are focused on enzymatic inhibitors. The study of the amphibians' skin had acquired great importance in the fields of biology and human health and represents an attractive and novel source for natural compounds with high potential in the development of new drugs. The present work exhibits the power of amphibian skins as a source of bioactive compounds. Herein we report the activity of extracts of two species from Hylidae family (H. cordobae and P. minuta) as reversible inhibitors of acetylcholinesterase and butyrylcholinesterase enzymes. Furthermore, the extracts inhibit MAO-B enzyme and showed antioxidant activities, acting on four important pathways of AD.
Assuntos
Doença de Alzheimer/metabolismo , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Inibidores da Colinesterase/isolamento & purificação , Inibidores da Colinesterase/farmacologia , Inibidores da Monoaminoxidase/isolamento & purificação , Inibidores da Monoaminoxidase/farmacologia , Pele/química , Acetilcolinesterase/efeitos dos fármacos , Acetilcolinesterase/metabolismo , Doença de Alzheimer/enzimologia , Animais , Antioxidantes/administração & dosagem , Anuros/classificação , Butirilcolinesterase/efeitos dos fármacos , Butirilcolinesterase/metabolismo , Células CHO , Inibidores da Colinesterase/administração & dosagem , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Cromatografia em Camada Fina , Cricetulus , Relação Dose-Resposta a Droga , Eletroforese em Gel de Poliacrilamida , Eritrócitos/efeitos dos fármacos , Eritrócitos/enzimologia , Humanos , Monoaminoxidase/efeitos dos fármacos , Monoaminoxidase/metabolismo , Inibidores da Monoaminoxidase/administração & dosagem , Especificidade da Espécie , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrofotometria UltravioletaRESUMO
High circulating nonesterified fatty acids (NEFAs) concentration, often reported in diabetes, leads to impaired glucose-stimulated insulin secretion (GSIS) through not yet well-defined mechanisms. Serotonin and dopamine might contribute to NEFA-dependent ß-cell dysfunction, since extracellular signal of these monoamines decreases GSIS. Moreover, palmitate-treated ß-cells may enhance the expression of the serotonin receptor Htr2c, affecting insulin secretion. Additionally, the expression of monoamine-oxidase type B (Maob) seems to be lower in islets from humans and mice with diabetes compared to nondiabetic islets, which may lead to increased monoamine concentrations. We assessed the expression of serotonin- and dopamine-related genes in islets from db/db and wild-type (WT) mice. In addition, the effect of palmitate and oleate on the expression of such genes, 5HT content, and GSIS in MIN6 ß-cell was determined. Lower Maob expression was found in islets from db/db versus WT mice and in MIN6 ß-cells in response to palmitate and oleate treatment compared to vehicle. Reduced 5HT content and impaired GSIS in response to palmitate (-25%; p < 0.0001) and oleate (-43%; p < 0.0001) were detected in MIN6 ß-cells. In conclusion, known defects of GSIS in islets from db/db mice and MIN6 ß-cells treated with NEFAs are accompanied by reduced Maob expression and reduced 5HT content.
Assuntos
Células Secretoras de Insulina/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Transcriptoma/genética , Acetilserotonina O-Metiltransferasa/efeitos dos fármacos , Acetilserotonina O-Metiltransferasa/genética , Animais , Arilalquilamina N-Acetiltransferase/efeitos dos fármacos , Arilalquilamina N-Acetiltransferase/genética , Catecol O-Metiltransferase/efeitos dos fármacos , Catecol O-Metiltransferase/genética , Linhagem Celular , Dopa Descarboxilase/efeitos dos fármacos , Dopa Descarboxilase/genética , Proteínas da Membrana Plasmática de Transporte de Dopamina/efeitos dos fármacos , Proteínas da Membrana Plasmática de Transporte de Dopamina/genética , Dopamina beta-Hidroxilase/efeitos dos fármacos , Dopamina beta-Hidroxilase/genética , Insulina/metabolismo , Secreção de Insulina , Células Secretoras de Insulina/metabolismo , Camundongos , Monoaminoxidase/efeitos dos fármacos , Monoaminoxidase/genética , Ácido Oleico/farmacologia , Ácido Palmítico/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Serotonina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/efeitos dos fármacos , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Transcriptoma/efeitos dos fármacos , Triptofano Hidroxilase/efeitos dos fármacos , Triptofano Hidroxilase/genética , Tirosina 3-Mono-Oxigenase/efeitos dos fármacos , Tirosina 3-Mono-Oxigenase/genéticaRESUMO
This work evaluates the central nervous effects in ICR strain mice of 2-ethylthio-7-methyl-4-(4-methylphenyl)pyrazolo[1,5-a][1,3,5]triazine (MH4b1), a compound obtained by an efficient one-step reaction of S,S-diethyl 4-methylbenzoylimidodithiocarbonate with 5-amino-3-methyl-1H-pyrazole, in order to assess its neuro-pharmacological profile. The tests applied were: maximal electroshock seizure (MES), pentylenetetrazole (PTZ) seizures, forced swimming, plus maze, marble burying, sleeping time, rota-rod and catalepsy. In addition, MH4b1 binding to the benzodiazepine site of the GABA-A receptor and MH4b1 inhibition of monoamine oxidase (MAO) subtypes A and B were evaluated. MH4b1 showed anticonvulsant effects in a dose dependent manner (30-300 mg/kg, p.o.) against MES and inhibition of MAO-B (IC50: 24.5 µM) without activity at the benzodiazepine site. These data suggest that MH4b1 has anticonvulsant properties related to MAO-B inhibition.
Este trabalho avalia o efeito do 2-etiltio-7-metil-4-(4-metilfenil)pirazol[1,5-a][1,3,5]triazina (MH4b1) no sistema nervoso central de camundongos ICR. O MH4b1 foi obtido por a reação de 4-metilbenzoilimidoditiocarbonato de S,S-dietil e 5-amino-3-metil-1H-pirazol em uma única etapa. O perfil neurofarmacológico foi realizado por testes de convulsão induzida por eletrochoque (MES) e pentilenotetrazol (PTZ) e por testes de nado forçado, labirinto em cruz, esconder as esferas, sono barbitúrico, rota-rod e catalepsia. Também foi avaliada a união do MH4b1 ao o local de ligação de benzodiazepínicos do receptor GABA-A e a capacidade inibitória do MH4b1 sobre a monoaminoxidase (MAO) A e B. O MH4b1 mostrou efeito anticonvulsivante dependente da dose (30-300 mg) no teste do MES e apresentou atividade inibitória da MAO-B (CI50: 24.5 µM) sem interagir com o local de ligação de benzodiazepínicos do receptor. Os resultados sugerem que o MH4b1 tem atividade anticonvulsivante relacionada com a inibição da MAO-B.
Assuntos
Camundongos , Pirazóis/farmacocinética , Convulsivantes/agonistas , Triazinas/farmacocinética , Eletrochoque/métodos , Monoaminoxidase/efeitos dos fármacosRESUMO
Although substrate conversion mediated by human monoaminooxidase (hMAO) has been associated with the deprotonated state of their amine moiety, data regarding the influence of protonation on substrate binding at the active site are scarce. Thus, in order to assess protonation influence, steered molecular dynamics (SMD) runs were carried out. These simulations revealed that the protonated form of the substrate serotonin (5-HT) exhibited stronger interactions at the protein surface compared to the neutral form. The latter displayed stronger interactions in the active site cavity. These observations support the possible role of the deprotonated form in substrate conversion. Multigrid docking studies carried out to rationalize the role of 5-HT protonation in other sites besides the active site indicated two energetically favored docking sites for the protonated form of 5-HT on the enzyme surface. These sites seem to be interconnected with the substrate/inhibitor cavity, as revealed by the tunnels observed by means of CAVER program. pK(a) calculations in the surface loci pointed to Glu³²7, Asp³²8, His488, and Asp¹³² as candidates for a possible in situ deprotonation step. Docking analysis of a group of inhibitors (structurally related to substrates) showed further interactions with the same two docking access sites. Interestingly, the protonated/deprotonated amine moiety of almost all compounds attained different docking poses in the active site, none of them oriented to the flavin moiety, thus producing a more variable and less productive orientations to act as substrates. Our results highlight the role of deprotonation in facilitating substrate conversion and also might reflect the necessity of inhibitor molecules to adopt specific orientations to achieve enzyme inhibition.
Assuntos
Simulação de Dinâmica Molecular , Inibidores da Monoaminoxidase/farmacologia , Monoaminoxidase/química , Prótons , Teoria Quântica , Sítios de Ligação , Domínio Catalítico , Humanos , Concentração Inibidora 50 , Modelos Moleculares , Monoaminoxidase/efeitos dos fármacos , Especificidade por SubstratoRESUMO
2-Arylthiomorpholine and 2-arylthiomorpholin-5-one derivatives, designed as rigid and/or non-basic phenylethylamine analogues, were evaluated as rat and human monoamine oxidase inhibitors. Molecular docking provided insight into the binding mode of these inhibitors and rationalized their different potencies. Making the phenylethylamine scaffold rigid by fixing the amine chain in an extended six-membered ring conformation increased MAO-B (but not MAO-A) inhibitory activity relative to the more flexible alpha-methylated derivative. The presence of a basic nitrogen atom is not a prerequisite in either MAO-A or MAO-B. The best K(i) values were in the 10(-8)M range, with selectivities towards human MAO-B exceeding 2000-fold.