RESUMO
Autism Spectrum Disorders (ASDs) are a group of neurodevelopmental pathologies whose current treatment is neither curative nor effective. Anthocyanins are naturally occurring compounds abundant in blueberries and in other red fruits which have been shown to be successful in the treatment of several neurological diseases, at least in in vitro and in vivo disease models. The aim of the present work was to study the ability of an anthocyanin-rich extract (ARE) obtained from Portuguese blueberries to alleviate autism-like symptoms in a valproic acid (VPA) mouse model of ASD and to get insights into the underlying molecular mechanisms of such benefits. Therefore, pregnant BALB/c females were treated subcutaneously with a single dose of VPA (500 mg/kg) or saline on gestational day 12.5. Male offspring mice were orally treated with the ARE from Portuguese blueberries (30 mg/kg/day) or the vehicle for three weeks, and further subjected to behavioral tests and biochemical analysis. Our data suggested that the ARE treatment alleviated autism-like behaviors in in utero VPA-exposed mice and, at the same time, decreased both neuroinflammation and gut inflammation, modulated the gut microbiota composition, increased serotonin levels in cerebral prefrontal cortex and gut, and reduced the synaptic dysfunction verified in autistic mice. Overall, our work suggests that anthocyanins extracted from Portuguese blueberries could constitute an effective strategy to ameliorate typical autistic behaviors through modulation of the microbiota-gut-brain axis.
Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Mirtilos Azuis (Planta) , Microbioma Gastrointestinal , Efeitos Tardios da Exposição Pré-Natal , Animais , Antocianinas/farmacologia , Antocianinas/uso terapêutico , Transtorno do Espectro Autista/tratamento farmacológico , Transtorno Autístico/tratamento farmacológico , Eixo Encéfalo-Intestino , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Portugal , Gravidez , Ácido Valproico/farmacologia , Ácido Valproico/uso terapêuticoRESUMO
Anthocyanins are naturally occurring polyphenols commonly found in fruits and vegetables. Numerous studies have described that anthocyanin-rich foods may play a crucial role in the prevention and treatment of different pathological conditions, which have encouraged their consumption around the world. Anthocyanins exhibit a significant neuroprotective role, mainly due to their well-recognized antioxidant and anti-inflammatory properties. Neuroinflammation is an intricate process relevant in both homeostatic and pathological circumstances. Since the progression of several neurological disorders relies on neuroinflammatory process, targeting brain inflammation has been considered a promising strategy in those conditions. Recent data have shown the anti-neuroinflammatory abilities of many anthocyanins and of their metabolites in the onset and development of several neurological disorders. In this review, it will be discussed the importance and the applicability of these polyphenolic compounds as neuroprotective agents and it will be also scrutinized the molecular mechanisms underlying the modulation of neuroinflammation by these natural compounds in the context of several brain diseases.
Assuntos
Antocianinas/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Antioxidantes/uso terapêutico , Encefalopatias/tratamento farmacológico , Neuroproteção/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Encefalopatias/metabolismo , Encefalopatias/patologia , HumanosRESUMO
Excess production of superoxide (O2(-)) and nitric oxide (NO) in blood vessel walls may occur early in atherogenesis leading to the formation of peroxynitrite, a strong oxidant and nitrating agent. This study was designed to determine the effect of diphenyl diselenide (PhSe)2, a synthetic organoselenium compound, in comparison with ebselen, on peroxynitrite-mediated endothelial damage. Experimental results showed that pre-incubation of BAEC (24 h) with low concentrations of (PhSe)2 (0.5 and 1 µM) protected the cells from peroxynitrite-dependent apoptosis and protein tyrosine nitration. The intracellular levels of GSH were almost completely depleted by peroxynitrite and, although the compounds did not restore its normal levels, (PhSe)2 per se significantly increased GSH in a concentration-dependent manner. Moreover, (PhSe)2, which was about two times more active as a GPx mimic than ebselen, induced a significantly higher increase in both cellular GPx expression and activity. Taking into account the kinetics of the reaction between peroxynitrite and (PhSe)2, our data indicate that (PhSe)2 protects BAEC against peroxynitrite-mediated cell damage not by a direct reaction, but rather by increasing cellular GPx expression as a consequence of enhanced nuclear translocation of Nrf-2, which together with the increase in intracellular GSH, may work catalytically to reduce peroxynitrite to nitrite.
Assuntos
Apoptose/efeitos dos fármacos , Azóis/farmacologia , Derivados de Benzeno/farmacologia , Células Endoteliais/efeitos dos fármacos , Compostos Organosselênicos/farmacologia , Ácido Peroxinitroso/toxicidade , Substâncias Protetoras/farmacologia , Análise de Variância , Animais , Aorta/citologia , Aorta/efeitos dos fármacos , Aorta/metabolismo , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Isoindóis , Fator 2 Relacionado a NF-E2RESUMO
Anthocyanins have received increasing attention because of their relatively high intake in humans and wide range of potential health-promoting effects, including anti-atherogenic properties. Evidences support their vascular protective effects but the involved molecular mechanisms have not been well clarified. The endothelium seems to have a central role in atherogenesis and apoptosis is emerging as a crucial event in this disease progression. Following our previous work on the biochemical pathways underlying peroxynitrite-triggered apoptosis in endothelial cells, here we investigated potential mechanisms responsible for the cytoprotective actions of three common anthocyanins, namely cyanidin- delphinidin- and pelargonidin-3-glucoside, against this process. Beyond their antioxidant properties, all these flavonoids, possessing either catecholic or monophenolic structures, were able to counteract peroxynitrite-induced apoptotic effects in endothelial cells through the inhibition of several crucial signaling cascades. Actually, pre-incubation of cells with 25 µM anthocyanins prevented them from peroxynitrite-mediated apoptosis, which was evaluated by the loss of mitochondrial membrane potential, caspases-9 and-3 activation, the increase in cytoplasmatic Bax levels and the inactivation of the PI3 K/Akt pathway. Moreover, they counteracted the translocation of Bax into the nucleus, as observed by immunocytochemistry and immunoblot, an event shown for the first time in endothelial cells apoptotic process. Such cellular actions could not be inferred from their in vitro antioxidant properties. These results suggest a potential role of dietary anthocyanins in the modulation of several apoptotic signaling pathways triggered by peroxynitrite in endothelial cells, supporting mechanistically their health benefits in the context of prevention of endothelial dysfunction and, ultimately, of atherosclerosis.
Assuntos
Antocianinas/farmacologia , Apoptose/efeitos dos fármacos , Endotélio Vascular/citologia , Glucosídeos/farmacologia , Ácido Peroxinitroso/farmacologia , Proteína X Associada a bcl-2/metabolismo , Animais , Aorta/citologia , Inibidores de Caspase , Bovinos , Ativação Enzimática/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Ácido Peroxinitroso/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Transporte Proteico/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Espécies Reativas de Oxigênio/antagonistas & inibidoresRESUMO
Chemical transformation studies were conducted on betulin and betulinic acid, common plant-derived lupane-type triterpenes. The concise synthesis, via a stepwise approach, of betulin and betulinic acid carbamate and N-acylheterocyclic containing derivatives is described. All new compounds, as well as betulinic acid were tested in vitro for their cytotoxic activity. Most of the compounds have shown a better cytotoxic profile than betulinic acid, including the synthesized betulin derivatives. Compounds 25 and 32 were the most promising derivatives, being up to 12-fold more potent than betulinic acid against human PC-3 cell lines (IC(50) values of 1.1 and 1.8 microM, respectively).
Assuntos
Antineoplásicos/síntese química , Carbamatos/química , Compostos Heterocíclicos/química , Triazóis/síntese química , Triterpenos/química , Triterpenos/síntese química , Antineoplásicos/química , Antineoplásicos/toxicidade , Carbamatos/síntese química , Carbamatos/toxicidade , Linhagem Celular Tumoral , DNA Topoisomerases Tipo I/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Triterpenos Pentacíclicos , Relação Estrutura-Atividade , Inibidores da Topoisomerase I , Triazóis/química , Triazóis/toxicidade , Triterpenos/toxicidade , Ácido BetulínicoRESUMO
The modulation of the microbiota-gut-brain axis with a view to preventing and treating brain disorders became recently a hot topic for the scientific community. Dietary polyphenols are multifaceted compounds that have demonstrated to be highly advantageous to counteract inflammation, oxidative stress, and neurodegeneration, among other pathological conditions, being useful in the prevention and treatment of several chronic disorders. The potential of these compounds to prevent and treat brain disorders has not been only related to their capacity to reach the brain, depending on their chemical structure, and interact directly with brain cells, but also to their ability to modulate the communication between the brain and the gut, interfering with multiple branches of this axis. Preclinical studies have demonstrated the potential of these food bioactive compounds in brain diseases, namely, neurodevelopmental, such as Down's syndrome and Autism spectrum disorder, neurodegenerative, such as Parkinson's disease and Alzheimer's disease, and psychiatric disorders, such as depression and anxiety. Until now, dietary polyphenols have been recognized as promising nutraceuticals to combat brain disorders. However, the impact of these compounds on the gut-brain interconnection remains poorly elucidated. Also, clinical assays are crucial to further support the beneficial effects of these compounds as demonstrated in preclinical research.
Assuntos
Encefalopatias/prevenção & controle , Dieta , Microbioma Gastrointestinal/efeitos dos fármacos , Polifenóis/farmacologia , Humanos , Doenças do Sistema Nervoso/prevenção & controle , Transtornos do Neurodesenvolvimento/prevenção & controle , Polifenóis/administração & dosagem , Polifenóis/farmacocinéticaRESUMO
Dietary polyphenols are multi-target compounds that have been considered promising candidates in strategies for the mitigation of neurological diseases, acting particularly through reduction of microglia-driven neuroinflammation. In this study, an anthocyanin-rich extract obtained from Portuguese blueberries was subjected to a simulated gastrointestinal digestion; after chemical characterisation, the potential of both non-digested and digested extracts to combat neuroinflammation was evaluated using a microglia N9 cell line. Although the extracts have markedly different chemical composition, both were efficient in reducing the production of either key inflammatory markers or reactive oxygen species and in enhancing reduced glutathione levels in activated cells. Furthermore, this protection was shown to be related to the suppression of nuclear factor kappa B (NF-kB) activation, and to a signal transducer and activator of transcription 1 (STAT1)-independent mechanism. These results demonstrate that the anthocyanin extract, after simulated digestion, maintains its efficacy against neuroinflammation, and can, therefore, assume a relevant role in prevention of neuroinflammation-related neurological disorders.
Assuntos
Antocianinas/química , Mirtilos Azuis (Planta)/química , Frutas/química , Inflamação/tratamento farmacológico , Microglia/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Glutationa/metabolismo , Camundongos , NF-kappa B/genética , NF-kappa B/metabolismo , Extratos Vegetais/química , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo , Fator de Necrose Tumoral alfaRESUMO
BACKGROUND: A disease-modifying therapy for Alzheimer's disease (AD) is still an unmet clinical need. The formation of amyloid-ß (Aß) requires the initial cleavage of the amyloid-ß protein precursor (AßPP) by BACE1 (beta-site AßPP cleaving enzyme 1), which is a prime therapeutic target for AD. OBJECTIVE: We aimed to design and develop a selective BACE1 inhibitor suitable to AD treatment. METHODS: The new BACE1 inhibitors consist on a chimeric peptide including a sequence related to the human Swedish mutant form of AßPP (AßPPswe) conjugated with the TAT carrier that facilitates cell membrane permeation and the crossing of the blood-brain barrier. Additionally to the chimeric peptide in the L-form, we developed a D-retroinverso chimeric peptide. The latter strategy, never used with BACE1 inhibitors, is considered to favor a significantly higher half-life and lower immunogenicity. RESULTS: We found that both chimeric peptides inhibit recombinant BACE1 activity and decrease Aß40/42 production in Neuro-2a (N2A) cells expressing AßPPswe without inducing cytotoxicity. The intraperitoneal administration of these peptides to 3xTg-AD mice decreased plasma and brain Aß40/42 levels, as well as brain soluble AßPPß production. Also, a reduction of insoluble Aß was observed in the brain after chronic treatment. Noteworthy, the chimeric peptides selectively inhibited the AßPP-ß cleavage relatively to the proteolysis of other BACE1 substrates such as close homologue of L1 (CHL1) and seizure-related gene 6 (SEZ6). CONCLUSIONS: Overall these new BACE1 chimeric peptideshold promising potential as a selective disease-modifying therapy for AD.
Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/efeitos dos fármacos , Precursor de Proteína beta-Amiloide/efeitos dos fármacos , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Fragmentos de Peptídeos/efeitos dos fármacos , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Secretases da Proteína Precursora do Amiloide/efeitos dos fármacos , Secretases da Proteína Precursora do Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/genética , Animais , Ácido Aspártico Endopeptidases/metabolismo , Barreira Hematoencefálica/metabolismo , Moléculas de Adesão Celular/metabolismo , Modelos Animais de Doenças , Humanos , CamundongosRESUMO
The treatment options for a patient diagnosed with Alzheimer's disease (AD) are currently limited. The cerebral accumulation of amyloid-ß (Aß) is a critical molecular event in the pathogenesis of AD. When the amyloidogenic ß-secretase (BACE1) is inhibited, the production of Aß peptide is reduced. Henceforth, the main goal of this study is the discovery of new small bioactive molecules that potentially reach the brain and inhibit BACE1. The work was conducted by a customized molecular modelling protocol, including pharmacophore-based and molecular docking-based virtual screening (VS). Structure-based (SB) and ligand-based (LB) pharmacophore models were designed to accurately screen several drug-like compound databases. The retrieved hits were subjected to molecular docking and in silico filtered to predict their ability to cross the blood-brain barrier (BBB). Additionally, 34 high-scoring compounds structurally distinct from known BACE1 inhibitors were selected for in vitro screening assay, which resulted in 13 novel hit-compounds for this relevant therapeutic target. This study disclosed new BACE1 inhibitors, proving the utility of combining computational and in vitro approaches for effectively predicting anti-BACE1 agents in the early drug discovery process.
Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Inibidores de Proteases/farmacologia , Secretases da Proteína Precursora do Amiloide/química , Secretases da Proteína Precursora do Amiloide/metabolismo , Barreira Hematoencefálica/metabolismo , Avaliação Pré-Clínica de Medicamentos , Ligantes , Simulação de Acoplamento Molecular , Inibidores de Proteases/metabolismo , Conformação Proteica , Interface Usuário-ComputadorRESUMO
It has been shown that the gut microbiota plays a crucial role in the maintenance of intestinal homeostasis. Additionally, it has been demonstrated that dysbiosis is closely correlated with chronic intestinal inflammation, contributing to the development of chronic intestinal diseases, and also of brain pathologies, including neurodegenerative, neurodevelopmental, and psychiatric disorders. Given the paramount importance of gut microbiota for the establishment of communication between the gut and the brain, the microbiota-gut-brain axis has been increasingly explored within the scope of neurosciences. In this review article, we present an overview of key cellular signaling pathways underlying chronic intestinal inflammation and the influence of chronic intestinal inflammation and dysbiosis on brain disorders. This will include the presentation of valuable data from recent preclinical and clinical research. We will also address the importance of probiotics and prebiotics to targeting the microbiota-gut-brain axis in the context of some brain disorders, where they are seen to be promising strategies for ameliorating brain disorders.
Assuntos
Encefalopatias/microbiologia , Encefalopatias/patologia , Encéfalo/patologia , Microbioma Gastrointestinal , Inflamação/patologia , Intestinos/microbiologia , Intestinos/patologia , Animais , Doença Crônica , HumanosRESUMO
Dietary polyphenols are bioactive compounds with potential in preventing and treating several chronic disorders, mainly due to their ability to modulate key pro-inflammatory and pro-oxidant signalling pathways. Although some studies have expressed concern about their efficacy in vivo, accumulating evidence has suggested that these compounds may achieve large concentrations in the gastrointestinal tract, which may be important in the context of intestinal and of neurological disorders, via modulation of the "gut-brain axis". Autism Spectrum disorders (ASD) are a group of lifelong neurodevelopmental disorders in which many patients suffer from gastrointestinal impairments. Thus, in the scope of these disorders, a growing number of studies have been focused on the microbiota-gut-brain axis. In this mini-review, we present gathered data on gut-to-brain communication in the scope of ASD and we address the advantages of polyphenols in the treatment of these disorders, presenting the more recent preclinical and clinical data on this issue. According to most studies, dietary polyphenols can be a promising strategy for the alleviation of ASD symptoms.
Assuntos
Transtorno do Espectro Autista/dietoterapia , Encéfalo/fisiopatologia , Gastroenteropatias/dietoterapia , Inflamação/dietoterapia , Polifenóis/farmacologia , Animais , HumanosRESUMO
Resveratrol (3,4',5-trihydroxystilbene) is a phytochemical believed to be partly responsible for the cardioprotective effects of red wine due to its numerous biological activities. Here, we studied biochemical pathways underlying peroxynitrite-mediated apoptosis in endothelial cells and potential mechanisms responsible for resveratrol cytoprotective action. Peroxynitrite triggered endothelial cell apoptosis through caspases-8, -9 and -3 activation implying both mitochondrial and death receptor apoptotic pathways. Resveratrol was able to prevent peroxynitrite-induced caspases-3 and -9 activation, but not caspase-8 activation. Additionally, peroxynitrite increased intracellular levels of Bax without affecting those of Bcl-2, increasing consequently the Bax/Bcl-2 ratio. This ratio decreased when cells where pre-incubated with 10 and 50 muM resveratrol, mainly due to resveratrol ability per se to increase Bcl-2 intracellular levels without affecting Bax intracellular levels. These results propose an additional mechanism whereby resveratrol may exert its cardioprotective effects and suggest a key role for Bcl-2 in the resveratrol anti-apoptotic action, especially in disrupting peroxynitrite-triggered mitochondrial pathway.
Assuntos
Apoptose/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Ácido Peroxinitroso/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/efeitos dos fármacos , Estilbenos/farmacologia , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Apoptose/fisiologia , Proteínas Reguladoras de Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/fisiopatologia , Caspases/efeitos dos fármacos , Caspases/metabolismo , Bovinos , Células Cultivadas , Citoproteção/efeitos dos fármacos , Citoproteção/fisiologia , Células Endoteliais/metabolismo , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Ácido Peroxinitroso/metabolismo , Ácido Peroxinitroso/toxicidade , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Receptores de Morte Celular/efeitos dos fármacos , Receptores de Morte Celular/metabolismo , Resveratrol , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Estilbenos/uso terapêutico , Proteína X Associada a bcl-2/efeitos dos fármacos , Proteína X Associada a bcl-2/metabolismoRESUMO
High levels of endogenous estrogens are associated with increased risks of breast cancer. Estrogen levels are mainly increased by the activity of the aromatase enzyme and reduced by oxidative/conjugative metabolic pathways. In this paper, we demonstrate for the first time that catechol estrogen metabolites are potent aromatase inhibitors, thus establishing a link between aromatase activity and the processes involved in estrogen metabolism. In particular, the anti-aromatase activity of a set of natural hydroxyl and methoxyl estrogen metabolites was investigated using biochemical methods and subsequently compared with the anti-aromatase potency of estradiol and two reference aromatase inhibitors. Catechol estrogens proved to be strong inhibitors with an anti-aromatase potency two orders of magnitude higher than estradiol. A competitive inhibition mechanism was found for the most potent molecule, 2-hydroxyestradiol (2-OHE(2)) and a rational model identifying the interaction determinants of the metabolites with the enzyme is proposed based on ab initio quantum-mechanical calculations. A strong relationship between activity and electrostatic properties was found for catechol estrogens. Moreover, our results suggest that natural catechol estrogens may be involved in the control mechanisms of estrogen production.
Assuntos
Inibidores da Aromatase/farmacologia , Aromatase/metabolismo , Estrogênios de Catecol/farmacologia , Inibidores da Aromatase/química , Catálise/efeitos dos fármacos , Estradiol/química , Estradiol/farmacologia , Estrogênios/química , Estrogênios/farmacologia , Estrogênios de Catecol/química , Humanos , Cinética , Estrutura MolecularRESUMO
Alzheimer's disease (AD) is a severe neurodegenerative disorder and the most common type of dementia in the elderly. The clinical symptoms of AD include a progressive loss of memory and impairment of cognitive functions interfering with daily life activities. The main neuropathological features consist in extracellular amyloid-ß (Aß) plaque deposition and intracellular Neurofibrillary tangles (NFTs) of hyperphosphorylated Tau. Understanding the pathophysiological mechanisms that underlie neurodegeneration in AD is essential for rational design of neuroprotective agents able to prevent disease progression. According to the "Amyloid Cascade Hypothesis" the critical molecular event in the pathogenesis of AD is the accumulation of Aß neurotoxic oligomers. Since the proteolytic processing of Amyloid Precursor Protein (APP) by ß-secretase (beta-site APP cleaving enzyme 1, BACE1) is the rate-limiting step in the production of Aß, this enzyme is considered a major therapeutic target and BACE1 inhibitors have the potential to be disease-modifying drugs for AD treatment. Therefore, intensive efforts to discover and develop inhibitors that can reach the brain and effectively inhibit BACE1 have been pursued by several groups worldwide. The aim of this review is to highlight the progress in the discovery of potent and selective small molecule BACE1 inhibitors over the past decade.
RESUMO
Agrimonia eupatoria L. (agrimony) is a medicinal plant largely used in traditional medicine. Recently, phytochemical studies on an agrimony hydro-alcoholic extract and a polyphenol-enriched fraction obtained from it were carried out. The fraction was found to possess a high concentration of flavan-3-ols, flavonols, flavones and phenolic acids. So, the main purpose of this study was to search out, the extract and fraction antioxidant potential and scavenging activity against the reactive species formed during inflammation and to establish a relationship between such activity and the phenolic composition. Results showed that both the extract and the fraction promptly reacted with DPPH denoting a general radical scavenger activity and a potential antioxidant capacity. They also reacted with superoxide anion, peroxyl and hydroxyl radicals as well as with the oxidant species, hydrogen peroxide, hypochlorous acid and peroxynitrite, strengthening their radical scavenger and antioxidant activities. In most assays, the polyphenol-enriched fraction was more efficient, pointing to a significant contribution of the polyphenols content to those activities. Our data suggest that the significant scavenging capacity of reactive species by polyphenols from Agrimonia eupatoria L., could be a mechanism of its anti-inflammatory activity.
Assuntos
Agrimonia/química , Flavonoides/farmacologia , Sequestradores de Radicais Livres/química , Extratos Vegetais/farmacologia , Espécies Reativas de Oxigênio/química , Peróxido de Hidrogênio/química , Radical Hidroxila/química , Ácido Hipocloroso/química , Ácido Peroxinitroso/química , Superóxidos/química , Xantina Oxidase/antagonistas & inibidoresRESUMO
Despite the actual therapeutic approaches for inflammatory bowel disease (IBD), efficient and secure alternative options remain a research focus. In this context, anthocyanins seem promising natural anti-inflammatory agents, but their action mechanisms and efficacy as compared with established drugs still require more clarification. The main aim of this study was to compare the anti-inflammatory action of a chemically characterized anthocyanin-rich fraction (ARF), obtained from Portuguese blueberries (Vaccinium corymbosum L.), with that of 5-aminosalicylic acid (5-ASA), a first-line drug in IBD, in a 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis rat model. Such fraction showed a high content and great molecular diversity of anthocyanins, with malvidin-3-galactoside and petunidin-3-arabinoside in the highest concentrations. After daily administration by intragastric infusion for 8 days, ARF, at a molar anthocyanin concentration about 30 times lower than 5-ASA, showed a higher effectiveness in counteracting the intestinal inflammation, as assessed by i) body weight variation and colon damage score, ii) reduction in leukocyte infiltration, iii) increase in antioxidant defenses and iv) by downregulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in colon tissue homogenates. The strong inhibition of COX-2 expression seems to be a crucial anti-inflammatory mechanism common to both ARF and 5-ASA, but the additional higher abilities of anthocyanins to downregulate iNOS and to decrease leukocytes infiltration and to increase antioxidant defenses in colon may account for the much higher anti-inflammatory action of anthocyanins. These data may contribute to the development of a promising natural approach in IBD management.
Assuntos
Antocianinas/farmacologia , Anti-Inflamatórios/farmacologia , Mirtilos Azuis (Planta)/química , Colite/tratamento farmacológico , Inflamação/tratamento farmacológico , Mesalamina/farmacologia , Animais , Antocianinas/metabolismo , Antioxidantes/metabolismo , Colite/induzido quimicamente , Colite/metabolismo , Colo/efeitos dos fármacos , Colo/metabolismo , Ciclo-Oxigenase 2/metabolismo , Inflamação/metabolismo , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/efeitos dos fármacos , Masculino , Óxido Nítrico Sintase Tipo II/metabolismo , Ratos , Ratos Wistar , Ácido Trinitrobenzenossulfônico/farmacologiaRESUMO
PARP-1 inhibition has been studied over the last decades for the treatment of various diseases. Despite the fact that several molecules act as PARP-1 inhibitors, a reduced number of compounds are used in clinical practice. To identify new compounds with a discriminatory PARP-1 inhibitory function, explicit-solvent molecular dynamics simulations using different inhibitors bound to the PARP-1 catalytic domain were performed. The representative structures obtained were used to generate structure-based pharmacophores, taking into account the dynamic features of receptor-ligand interactions. Thereafter, a virtual screening of compound databases using the pharmacophore models obtained was performed and the hits retrieved were subjected to molecular docking-based scoring. The drug-like molecules featuring the best ranking were evaluated for their PARP-1 inhibitory activity and IC50 values were calculated for the top scoring docked compounds. Altogether, three new PARP-1 inhibitor chemotypes were identified.
Assuntos
Modelos Moleculares , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Domínio Catalítico , Bases de Dados de Produtos Farmacêuticos , Humanos , Ligantes , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Relação Estrutura-AtividadeRESUMO
Atherosclerosis, the main cause of cardiovascular disease (CD), is a chronic inflammatory condition associated with an overproduction of oxidant species, namely peroxynitrite, which is a powerful oxidant that reacts directly with all biomolecules. Glutathione is an efficient scavenger of peroxynitrite, so, modulation of glutathione synthesis may provide a strategy to selectively protect cells from this oxidant. Here, we investigated the ability of resveratrol, a component of red wine, to prevent peroxynitrite-mediated endothelial cells toxicity and the underlying mechanism. Bovine aortic endothelial cells (BAEC) in primary cultures were treated with authentic peroxynitrite and the cell viability and intracellular glutathione contents were assessed. Our results demonstrate that a long pre-incubation (14 h) of BAEC with resveratrol (1-50 microM) leads to the endothelial cells rescue from injury triggered by authentic peroxynitrite by a mechanism of up-regulation of the intracellular GSH content, for the highest resveratrol concentration tested. Considering the importance of GSH in regulation of cell life, this capacity of resveratrol provides a new mechanism for its cardioprotective effects and may contribute to the development of novel therapeutic strategies.
Assuntos
Apoptose/efeitos dos fármacos , Citoproteção/efeitos dos fármacos , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Glutationa/metabolismo , Ácido Peroxinitroso/farmacologia , Animais , Butionina Sulfoximina/farmacologia , Bovinos , Forma Celular , Células Cultivadas , Células Endoteliais/efeitos dos fármacos , Resveratrol , Estilbenos/farmacologiaRESUMO
This study investigated the involvement of nuclear factor erythroid 2 (Nrf2) and peroxisome proliferator-activated receptor-gamma (PPAR-γ) pathways in the protection afforded by two polyphenols abundant in diet, cyanidin-3-glucoside and resveratrol, against cytokine-induced inflammation and oxidative insult in HT-29 intestinal cells, in comparison with the drug 5-aminosalicylic acid (5-ASA). Our data show for the first time that in cytokine-challenged cells, cyanidin-3-glucoside and resveratrol induced Nrf2 activation, increased hemoxygenase-1 and glutamate cysteine ligase mRNA expression, enhanced reduced glutathione to oxidized glutathione ratio and inhibited reactive species production, at much lower concentrations than 5-ASA. Unlike cyanidin-3-glucoside, resveratrol and 5-ASA also increased nuclear levels of PPAR-γ in cytokine-stimulated cells. In conclusion, both polyphenols might be interesting as nutraceuticals, giving complementary benefits to conventional drugs against intestinal inflammation, typically present in patients with inflammatory bowel disease.
Assuntos
Antocianinas/farmacologia , Anti-Inflamatórios/farmacologia , Citoproteção/efeitos dos fármacos , Glucosídeos/farmacologia , Intestinos/citologia , Mesalamina/farmacologia , Fator 2 Relacionado a NF-E2/metabolismo , PPAR gama/metabolismo , Estilbenos/farmacologia , Antocianinas/química , Anti-Inflamatórios/química , Catálise/efeitos dos fármacos , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Citocinas/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Glucosídeos/química , Dissulfeto de Glutationa/metabolismo , Células HT29 , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Humanos , Espaço Intracelular/metabolismo , Mesalamina/química , Subunidades Proteicas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Resveratrol , Estilbenos/químicaRESUMO
Peroxynitrite has been shown to modify low-density lipoproteins (LDL) into a form recognized by the macrophage scavenger receptor, suggesting that it may play a significant role in atherogenesis. Considering that the mechanisms underlying LDL modifications by this agent have not been well elucidated, the aim of this study was to characterize the chemical modifications of either the lipid or the protein moieties mediated by synthesized peroxynitrite (preformed) or formed in situ by SIN-1, and evaluate the protective effects of some dietary phenolic acids. Preformed peroxynitrite does not induce LDL lipid peroxidation, as assessed either by formation of conjugated diene isomers or degradation of fatty acids and cholesteryl esters, although a rapid loss of alpha-tocopherol content occurs. Also, peroxynitrite formed in situ induces only a slight lipid oxidation. In contrast, under conditions where the LDL lipid moiety is not significantly oxidized, peroxynitrite either preformed or formed in situ rapidly elicit significant LDL apoprotein modifications, as evaluated by an increase in carbonyl groups formation and by great decrease in intrinsic tryptophan and thiol groups, in a concentration-dependent manner, that are accompanied by an increase in the LDL net negative charge, leading to an increase in electrophoretic mobility. Phenolic acids, namely caffeic, chlorogenic and ferulic, inhibit all these processes in a concentration dependent way, being the catechols the most efficient. UV spectral analysis of phenols upon interaction with peroxynitrite suggest that, in our assay conditions, such protection is related with the scavenging of this agent by either electron donation for the catechols, caffeic and chlorogenic acids, or nitration for the monophenol ferulic acid. Our data point that in contrast with other physiological oxidants, as ferrylmyoglobin or copper, peroxynitrite triggers the rapid damage to LDL primarily by protein and not lipid oxidation, and that such process is inhibited by dietary phenolic derivatives of cinnamic acids.