RESUMO
Inflammatory bowel diseases (IBDs) are characterized by an inflammatory and oxidative stress condition in the intestinal tissue. In this study, we evaluated the effect of plumericin, one of the main bioactive components of Himatanthus sucuuba (Woodson) bark, on intestinal inflammation and oxidative stress, both in vitro and in vivo. The effect of plumericin (0.5-2 µM) in vitro was evaluated in rat intestinal epithelial cells (IEC-6) treated with lipopolysaccharides from E. coli (10 µg/mL) plus interferon-γ (10 U/mL). Moreover, a 2,4,6-dinitrobenzene sulfonic acid (DNBS)-induced colitis model was used to evaluate the anti-inflammatory and antioxidant activity of plumericin (3 mg/kg) in vivo. The results showed that plumericin significantly reduces intestinal inflammatory factors such as tumor necrosis factor-α, cyclooxygenase-2 and inducible nitric oxide synthase expression, and nitrotyrosine formation. Plumericin also inhibited nuclear factor-κB translocation, reactive oxygen species (ROS) release, and inflammasome activation. Moreover, plumericin activated the nuclear factor erythroid-derived 2 pathway in IEC-6. Using the DNBS-induced colitis model, a significant reduction in the weight loss and in the development of the macroscopic and histologic signs of colon injury, together with a reduced inflammatory and oxidative stress state, were observed in plumericin-treated mice. These results indicate that plumericin exerts a strong anti-inflammatory and antioxidant activity. Thus, it might be a candidate for the development of a new pharmacologic approach for IBDs treatment.
Assuntos
Anti-Inflamatórios/farmacologia , Colo/efeitos dos fármacos , Indenos/farmacologia , Inflamação/tratamento farmacológico , Iridoides/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Linhagem Celular , Colite/tratamento farmacológico , Colite/metabolismo , Colo/metabolismo , Ciclo-Oxigenase 2/metabolismo , Inflamação/metabolismo , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Masculino , Camundongos , NF-kappa B/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Protein tyrosine phosphatase 1B plays a significant role in type 2 diabetes mellitus and other diseases and is therefore considered a new drug target. Within this study, an acetone extract from the lichen Stereocaulon evolutum was identified to possess strong protein tyrosine phosphatase 1B inhibition in a cell-free assay (IC50 of 11.8 µg/mL). Fractionation of this bioactive extract led to the isolation of seven known molecules belonging to the depsidones and the related diphenylethers and one new natural product, i.e., 3-butyl-3,7-dihydroxy-5-methoxy-1(3H)-isobenzofurane. The isolated compounds were evaluated for their inhibition of protein tyrosine phosphatase 1B. Two depsidones, lobaric acid and norlobaric acid, and the diphenylether anhydrosakisacaulon A potently inhibited protein tyrosine phosphatase 1B with IC50 values of 12.9, 15.1, and 16.1 µM, respectively, which is in the range of the protein tyrosine phosphatase 1B inhibitory activity of the positive control ursolic acid (IC50 of 14.4 µM). Molecular simulations performed on the eight compounds showed that i) a contact between the molecule and the four main regions of the protein is required for inhibitory activity, ii) the relative rigidity of the depsidones lobaric acid and norlobaric acid and the reactivity related to hydrogen bond donors or acceptors, which interact with protein tyrosine phosphatase 1B key amino acids, are involved in the bioactivity on protein tyrosine phosphatase 1B, iii) the cycle opening observed for diphenylethers decreased the inhibition, except for anhydrosakisacaulon A where its double bond on C-8 offsets this loss of activity, iv) the function present at C-8 is a determinant for the inhibitory effect on protein tyrosine phosphatase 1B, and v) the more hydrogen bonds with Arg221 there are, the more anchorage is favored.
Assuntos
Ascomicetos , Inibidores Enzimáticos , Líquens , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Ascomicetos/química , Diabetes Mellitus Tipo 2 , Inibidores Enzimáticos/farmacologia , Líquens/químicaRESUMO
Sigesbeckia orientalis, more commonly referred to as Herba Sigesbeckiae or Xi Xian Cao in traditional Chinese medicine and hy thiêm in traditional Vietnamese medicine, is used in China and Vietnam to treat inflammatory diseases such as arthritis, rheumatism, and joint pain. In initial investigations, the dichloromethane extract from the aerial parts of S. orientalis showed distinct inhibitory effects on the release of interleukin-8 in human neutrophils. Therefore, the purpose of the present study was the phytochemical investigation of the bioactive dichloromethane extract and the in vitro analysis of the effects of the isolated compounds on interleukin-8, interleukin-1ß, tumor necrosis factor-α, and monocyte chemoattractant protein 1 release, and surface expression of adhesion molecules (CD11a, CD11b, and CD62L) in lipopolysaccharide-stimulated human neutrophils to identify the active principle(s). The separation of the bioactive dichloromethane extract using various chromatographic techniques led to the isolation of nine compounds. Their chemical structures were elucidated from nuclear magnetic resonance and mass spectrometry data. One diterpene, 17(13 â 14)-abeo-ent-3S*,13S*,16-trihydroxystrob-8(15)-ene, was identified as a new natural product. Three germacranolide sesquiterpene lactones inhibited interleukin-8 production with IC50 values between 1.6 and 6.3 µM, respectively, and tumor necrosis factor-α production with IC50 values between 0.9 and 3.3 µM, respectively. Furthermore, they significantly inhibited interleukin-1ß and monocyte chemoattractant protein 1 production and diminished the effects of lipopolysaccharide on the surface expression of the adhesion molecules CD11a, CD11b, and CD62L. These findings support the traditional use of S. orientalis in the treatment of inflammatory diseases.
Assuntos
Anti-Inflamatórios , Diterpenos , Anti-Inflamatórios/farmacologia , China , Humanos , Lactonas , Compostos Fitoquímicos , Extratos Vegetais/farmacologia , Fator de Necrose Tumoral alfa , VietnãRESUMO
Natural products comprise a rich reservoir for innovative drug leads and are a constant source of bioactive compounds. To find pharmacological targets for new or already known natural products using modern computer-aided methods is a current endeavor in drug discovery. Nature's treasures, however, could be used more effectively. Yet, reliable pipelines for the large-scale target prediction of natural products are still rare. We developed an in silico workflow consisting of four independent, stand-alone target prediction tools and evaluated its performance on dihydrochalcones (DHCs)-a well-known class of natural products. Thereby, we revealed four previously unreported protein targets for DHCs, namely 5-lipoxygenase, cyclooxygenase-1, 17ß-hydroxysteroid dehydrogenase 3, and aldo-keto reductase 1C3. Moreover, we provide a thorough strategy on how to perform computational target predictions and guidance on using the respective tools.
Assuntos
Produtos Biológicos/química , Simulação por Computador , Descoberta de Drogas , Inibidores Enzimáticos/química , Oxirredutases , Avaliação Pré-Clínica de Medicamentos , Humanos , Oxirredutases/antagonistas & inibidores , Oxirredutases/químicaRESUMO
Tyrosinase (Tyr) catalyzes the rate-limiting step of melanogenesis in human skin and is thus the main target for treating pigmentation disorders today. This has led to an increased research interest in Tyr inhibitors during the last decades, with a frequent focus on polyphenols. In the early stages of drug discovery, it is typical to avoid the high costs of human Tyr by using the more economic mushroom tyrosinase (mh-Tyr). Since some polyphenols are accepted as substrates by mh-Tyr, the present study aimed to more generally investigate this enzyme's specificity toward polyphenols and to discuss its significance in the context of bioactivity-guided fractionation. Mh-Tyr substrates can change the sample color during an inhibition assay, leading to unreliable inhibition constants or to the discontinuation of a bioactivity-guided fractionation campaign. A data set of 56 natural products was investigated and classified into assay interferers (AIs) and noninterferers, using a spectrophotometric and an LC-ESIHRMS assay. Based on these experimental findings, structure-activity relationships defining AIs were deduced and implemented into an in silico tool that will allow for rapid prescreening in the future. We anticipate that these results will aid in the search for new Tyr inhibitors and contribute to the understanding of this enzyme, as well as its optimal use in pharmacological research.
Assuntos
Agaricales/enzimologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Simulação de Acoplamento Molecular , Monofenol Mono-Oxigenase/química , Relação Estrutura-Atividade , Especificidade por SubstratoRESUMO
During chronic inflammation, neutrophils acting locally as effector cells not only activate antibacterial defense but also promote the inflammatory response. Interleukin 8 (IL-8), the main cytokine produced by activated neutrophils, positively correlates with the severity of respiratory tract diseases. By screening European plants traditionally used for treating respiratory tract diseases, we found that extracts of aerial parts of Eupatorium cannabinum inhibit IL-8 release from neutrophils. Using bioassay-guided fractionation, we identified five sesquiterpene lactones, eupatoriopicrin (1), 5'-deoxyeupatoriopicrin (2), hiyodorilactone A (3), 3-hydroxy-5'- O-acetyleupatoriopicrin = hiyodorilactone D (4), and hiyodorilactone B (5), that efficiently (IC50 < 1 µM) inhibited IL-8 and TNF-α release in lipopolysaccharide (LPS)-stimulated human neutrophils. Moreover, all these sesquiterpene lactones suppressed the adhesion of human neutrophils to an endothelial monolayer by downregulating the expression of the ß2 integrin CD11b/CD18 on the neutrophil surface. Furthermore, eupatoriopicrin efficiently suppressed LPS-induced phosphorylation of p38 MAPK and ERK and attenuated neutrophil infiltration in the thioglycolate-induced peritonitis model in mice. Altogether, these results demonstrate the potential of the sesquiterpene lactone eupatoriopicrin as a lead substance for targeting inflammation.
Assuntos
MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Interleucina-8/antagonistas & inibidores , Neutrófilos/efeitos dos fármacos , Sesquiterpenos/farmacologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Antígenos CD18/antagonistas & inibidores , Células Cultivadas , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/fisiologia , Humanos , Interleucina-8/biossíntese , Neutrófilos/fisiologia , Extratos Vegetais/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Sesquiterpenos/metabolismo , Fator de Necrose Tumoral alfa/biossínteseRESUMO
Melodamide A, a phenolic amide from the leaves of Melodorum fruticosum Lour., has previously shown pronounced anti-inflammatory activity. In order to rapidly isolate larger quantities for biological testing, a fast, one-step isolation method by centrifugal partition chromatography was developed within this study. Fractionation of the dichloromethane extract was performed with a two-phase solvent system consisting of n-hexane, ethyl acetate, methanol, and water (3:7:5:5, v/v), leading to the isolation of melodamide A with a purity of >90% and a yield of 6.7 w% within 32 min. The developed method can also be used in dual mode for the enrichment of further constituents like flavonoids or chalcones. In order to support the centrifugal partition chromatography method development, additionally, a high-performance liquid chromatography method was established and validated to determine quantities of melodamide A in plant material and crude extracts. Analysis of M. fruticosum leaves and a dichloromethane extract obtained from this plant material showed a total melodamide A content of 0.19 ± 0.008 and 8.9 ± 0.249 w%, respectively.
RESUMO
In the course of this project, 133 plants were evaluated on their ability to inhibit tyrosinase, a key enzyme in melanogenesis. The screening was performed by means of a HPTLC autographic assay, resulting in the selection of three plants, Asplenium trichomanes, Pinus uncinata, and Scutellaria altissima, with promising tyrosinase inhibiting activities. With the aid of the HPTLC assay, it was not only possible to select the most interesting plant extracts, but also to monitor the activity-guided fractionation which, in a relatively short time period, led to the isolation of active principles. Benzoic acid, roseoside, and dihydrovomifoliol-O-ß-d-glucopyranoside could be identified as tyrosinase inhibitors present in P. uncinata. Globularin turned out to be the active principle of S. altissima, and 4-ethenylphenyl 6-O-(6-deoxy-α-l-mannopyranosyl)-ß-d-glucopyranoside was detected as tyrosinase inhibitor of A. trichomanes. The pure compounds were tested also in a 96 well-plate assay in order to determine their IC50 values. The lowest IC50 value (42â µm) could be obtained for globularin, whereas the other compounds, e. g., benzoic acid exhibited a rather high IC50 value (IC50 =552â µm). This stood in clear contrast to the autographic assay, but is has to be taken into account that the outcome of the autography assay is not only depending on the IC50 value of a compound, but also on the content of the respective constituent in the extract.
Assuntos
Inibidores Enzimáticos/farmacologia , Gleiquênias/química , Monofenol Mono-Oxigenase/antagonistas & inibidores , Pinus/química , Extratos Vegetais/farmacologia , Scutellaria/química , Agaricales/enzimologia , Ácido Benzoico/química , Ácido Benzoico/isolamento & purificação , Ácido Benzoico/farmacologia , Cromatografia em Camada Fina , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Europa (Continente) , Glucosídeos/química , Glucosídeos/isolamento & purificação , Glucosídeos/farmacologia , Conformação Molecular , Monofenol Mono-Oxigenase/metabolismo , Norisoprenoides/química , Norisoprenoides/isolamento & purificação , Norisoprenoides/farmacologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Especificidade da Espécie , Relação Estrutura-AtividadeRESUMO
In an initial screening, the dichloromethane extract from the leaves of Melodorum fruticosum showed distinct inhibitory effects on the release of interleukin-8 (IL-8) in human neutrophils. Therefore, the aim of the present study was the phytochemical and pharmacological investigation of this extract, to better understand which compounds might be responsible for the anti-inflammatory effect. Phytochemical analysis led to the isolation of 12 known compounds and two new natural products, 5-hydroxy-6-(2-hydroxybenzyl)-4',7-dimethoxyflavanone (13) and 2',4'-dihydroxy-3'-(2-hydroxybenzyl)-4,6'-dimethoxychalcone (14). The influence of the isolated compounds on the production and release of the pro-inflammatory factors IL-8, tumor necrosis factor alpha (TNF-α), reactive oxygen species (ROS), and adhesion molecules (CD62L and CD11b) in human neutrophils was evaluated. Three constituents, melodamide A, 2',4'-dihydroxy-4,6'-dimethoxychalcone, and 2',6'-dihydroxy-4'-methoxychalcone, showed significant inhibition of IL-8 release (IC50 =6.6, 8.6, and 11.6â µm, respectively) and TNF-α production (IC50 =4.5, 13.3, and 6.2â µm, respectively).
Assuntos
Annonaceae/química , Anti-Inflamatórios não Esteroides/farmacologia , Neutrófilos/efeitos dos fármacos , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/isolamento & purificação , Antígeno CD11b/antagonistas & inibidores , Antígeno CD11b/metabolismo , Relação Dose-Resposta a Droga , Humanos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Interleucina-8/antagonistas & inibidores , Interleucina-8/metabolismo , Selectina L/antagonistas & inibidores , Selectina L/metabolismo , Neutrófilos/metabolismo , Folhas de Planta/química , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Relação Estrutura-Atividade , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/metabolismoRESUMO
NADPH oxidase 4 (Nox4) has recently been implicated as driving force in cellular senescence. Thus, there is growing interest to develop Nox4 inhibitors, which might be valuable agents for cosmeceutical applications. Alpine plants represent a valuable source for the identification of novel bioactive natural products with anti-ageing effects, especially substances that protect plants against UV radiation, which is also known to contribute to the ageing of human skin. Therefore, the aim of this study was to identify novel Nox4 inhibitors from alpine plants. Within an initial screening of extracts of alpine plants on their ability to inhibit Nox4 activity in HEK cells, the methanolic extract of the subaerial parts of Lycopus europaeus showed a strong inhibition of Nox4 (81% chemiluminescence quenching) and a simultaneously high cell viability (91% vitality). Rosmarinic acid was isolated and identified as the major compound in this bioactive extract. It showed a dose dependent inhibitory activity on Nox4 with an IC50 of 1 µM. Moreover, it also showed a significant inhibitory activity on Nox2 in the low micromolar range, whereas no inhibition of Nox5 was detected. Further investigations confirmed that the observed effects of rosmarinic acid on Nox2 and Nox4 are real inhibitory activities, and not due to ROS scavenging effects. Therefore, L. europaeus, which we demonstrated to be a good source of rosmarinic acid, has great potential for usage in cosmeceutical products with anti-ageing activity.
Assuntos
Cinamatos/isolamento & purificação , Cinamatos/farmacologia , Depsídeos/isolamento & purificação , Depsídeos/farmacologia , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Lycopus/química , NADPH Oxidase 4/metabolismo , Linhagem Celular , Sobrevivência Celular , Cinamatos/química , Depsídeos/química , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Regulação da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Humanos , Metanol/química , Metanol/isolamento & purificação , Metanol/farmacologia , NADPH Oxidase 2/metabolismo , Componentes Aéreos da Planta/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Ácido RosmarínicoRESUMO
There is a rapid increase in the percentage of elderly people in Europe. Consequently, the prevalence of age-related diseases will also significantly increase. Therefore, the main goal of MediHealth, an international research project, is to introduce a novel approach for the discovery of active agents of food plants from the Mediterranean diet and other global sources that promote healthy ageing. To achieve this goal, a series of plants from the Mediterranean diet and food plants from other origins are carefully selected and subjected to in silico, cell-based, in vivo (fly and mouse models), and metabolism analyses. Advanced analytical techniques complement the bio-evaluation process for the efficient isolation and identification of the bioactive plant constituents. Furthermore, pharmacological profiling of bioactive natural products, as well as the identification and synthesis of their metabolites, is carried out. Finally, optimization studies are performed in order to proceed to the development of innovative nutraceuticals, dietary supplements or herbal medicinal products. The project is based on an exchange of researchers between nine universities and four companies from European and non-European countries, exploiting the existing complementary multidisciplinary expertise. Herein, the unique and novel approach of this interdisciplinary project is presented.
Assuntos
Produtos Biológicos/química , Dieta Mediterrânea , Suplementos Nutricionais/análise , Envelhecimento Saudável/efeitos dos fármacos , Compostos Fitoquímicos/isolamento & purificação , Plantas Comestíveis/química , Animais , Disponibilidade Biológica , Produtos Biológicos/farmacocinética , Produtos Biológicos/farmacologia , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/fisiologia , Envelhecimento Saudável/fisiologia , Humanos , Comunicação Interdisciplinar , Cooperação Internacional , Camundongos , Camundongos Endogâmicos C57BL , Ciências da Nutrição/instrumentação , Ciências da Nutrição/métodos , Compostos Fitoquímicos/química , Plantas Medicinais/químicaRESUMO
Skin is continuously exposed to a variety of environmental stresses, including ultraviolet (UV) radiation. UVB is an inherent component of sunlight that crosses the epidermis and reaches the upper dermis, leading to increased oxidative stress, activation of inflammatory response and accumulation of DNA damage among other effects. The increase in UVB radiation on earth due to the destruction of stratospheric ozone poses a major environmental threat to the skin, increasing the risk of damage with long-term consequences, such as photoaging and photocarcinogenesis. Extracts from plants and natural compounds have been historically used in traditional medicine in the form of teas and ointments but the effect of most of these compounds has yet to be verified. Regarding the increasing concern of the population with issues related to quality of life and appearance, the cosmetic market for anti-aging and photoprotective products based on natural compounds is continuously growing, and there is increasing requirement of expansion on research in this field. In this review we summarized the most current and relevant information concerning plant extracts and natural compounds that are able to protect or mitigate the deleterious effects caused by photoaging in different experimental models.
Assuntos
Produtos Biológicos/farmacologia , Cosméticos/farmacologia , Extratos Vegetais/farmacologia , Envelhecimento da Pele/efeitos dos fármacos , Pele/efeitos dos fármacos , Luz Solar/efeitos adversos , Raios Ultravioleta/efeitos adversos , Animais , Produtos Biológicos/toxicidade , Cosméticos/toxicidade , Humanos , Modelos Animais , Extratos Vegetais/toxicidade , Medição de Risco , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/efeitos da radiação , Pele/metabolismo , Pele/patologia , Pele/efeitos da radiaçãoRESUMO
17ß-Hydroxysteroid dehydrogenase type 2 (17ß-HSD2) converts the active steroid hormones estradiol, testosterone, and 5α-dihydrotestosterone into their weakly active forms estrone, Δ4-androstene-3,17-dione, and 5α-androstane-3,17-dione, respectively, thereby regulating cell- and tissue-specific steroid action. As reduced levels of active steroids are associated with compromised bone health and onset of osteoporosis, 17ß-HSD2 is considered a target for antiosteoporotic treatment. In this study, a pharmacophore model based on 17ß-HSD2 inhibitors was applied to a virtual screening of various databases containing natural products in order to discover new lead structures from nature. In total, 36 hit molecules were selected for biological evaluation. Of these compounds, 12 inhibited 17ß-HSD2 with nanomolar to low micromolar IC50 values. The most potent compounds, nordihydroguaiaretic acid (1), IC50 0.38 ± 0.04 µM, (-)-dihydroguaiaretic acid (4), IC50 0.94 ± 0.02 µM, isoliquiritigenin (6), IC50 0.36 ± 0.08 µM, and ethyl vanillate (12), IC50 1.28 ± 0.26 µM, showed 8-fold or higher selectivity over 17ß-HSD1. As some of the identified compounds belong to the same structural class, structure-activity relationships were derived for these molecules. Thus, this study describes new 17ß-HSD2 inhibitors from nature and provides insights into the binding pocket of 17ß-HSD2, offering a promising starting point for further research in this area.
Assuntos
17-Hidroxiesteroide Desidrogenases/antagonistas & inibidores , Produtos Biológicos/farmacologia , Inibidores Enzimáticos/farmacologia , Produtos Biológicos/química , Inibidores Enzimáticos/química , Etiocolanolona/análogos & derivados , Humanos , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade , Testosterona/metabolismoRESUMO
There is an increasing interest in the development of soluble epoxide hydrolase (sEH) inhibitors, which block the degradation of endogenous anti-inflammatory epoxyeicosatrienoic acids. Within this study, a set of pharmacophore models for sEH inhibitors was developed. The Specs database was virtually screened and a cell-free sEH activity assay was used for the biological investigation of virtual hits. In total, out of 48 tested compounds, 19 were sEH inhibitors with IC50 < 10 µM, representing a prospective true positive hit rate of 40%. Six of these compounds displayed IC50 values in the low nanomolar range. The most potent compound 21, a urea derivative, inhibited sEH with an IC50 = 4.2 nM. The applied approach also enabled the identification of diverse chemical scaffolds, e.g. the pyrimidinone derivative 29 (IC50 = 277 nM). The generated pharmacophore model set therefore represents a valuable tool for the selection of compounds for biological testing.
Assuntos
Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Epóxido Hidrolases/antagonistas & inibidores , Epóxido Hidrolases/química , Domínio Catalítico , Humanos , Modelos Moleculares , Solubilidade , Relação Estrutura-Atividade , Interface Usuário-ComputadorRESUMO
Over the last twenty years, tocotrienol analogues raised great interest because of their higher level and larger domain of biological activities when compared with tocopherols. Amongst the most promising therapeutic application, anti-inflammatory potency has been evaluated through the inhibition of various mediators of inflammation. Here, we worked on the isolation of two natural isoforms of garcinoic acid (i.e., δ and γ) from two different sources, respectively, Garcinia kola seeds and Garcinia amplexicaulis bark. We also developed semisynthetic strategies to access the other two non-natural α- and ß-garcinoic acid isoforms. In the next stage of our work, microsomal prostaglandin E2 synthase was defined as a target to evaluate the anti-inflammatory potential of the four garcinoic acid isomers. Both dimethylated isoforms, ß- and γ-garcinoic acid, exhibited the lowest IC50, 2.8 µM and 2.0 µM, respectively. These results showed that the affinity of tocotrienol analogues to microsomal prostaglandin E2 synthase-1 most probably contributes to the anti-inflammatory potential of this class of derivatives.
Assuntos
Benzopiranos/isolamento & purificação , Garcinia/química , Extratos Vegetais/isolamento & purificação , Prostaglandina-E Sintases/antagonistas & inibidores , Benzopiranos/síntese química , Benzopiranos/química , Linhagem Celular , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Humanos , Isomerismo , Casca de Planta/química , Extratos Vegetais/farmacologiaRESUMO
Natural products have always been exploited to promote health and served as a valuable source for the discovery of new drugs. In this review, the great potential of natural compounds and medicinal plants for the treatment or prevention of cardiovascular and metabolic disorders, global health problems with rising prevalence, is addressed. Special emphasis is laid on natural products for which efficacy and safety have already been proven and which are in clinical trials, as well as on plants used in traditional medicine. Potential benefits from certain dietary habits and dietary constituents, as well as common molecular targets of natural products, are also briefly discussed. A glimpse at the history of statins and biguanides, two prominent representatives of natural products (or their derivatives) in the fight against metabolic disease, is also included. The present review aims to serve as an "opening" of this special issue of Molecules, presenting key historical developments, recent advances, and future perspectives outlining the potential of natural products for prevention or therapy of cardiovascular and metabolic disease.
Assuntos
Produtos Biológicos/uso terapêutico , Doenças Cardiovasculares/tratamento farmacológico , Doenças Metabólicas/tratamento farmacológico , Plantas Medicinais , Biguanidas/uso terapêutico , Descoberta de Drogas , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêuticoRESUMO
The Eighth Central European Conference "Chemistry towards Biology" was held in Brno, Czech Republic, on August 28-September 1, 2016 to bring together experts in biology, chemistry and design of bioactive compounds; promote the exchange of scientific results, methods and ideas; and encourage cooperation between researchers from all over the world. The topics of the conference covered "Chemistry towards Biology", meaning that the event welcomed chemists working on biology-related problems, biologists using chemical methods, and students and other researchers of the respective areas that fall within the common scope of chemistry and biology. The authors of this manuscript are plenary speakers and other participants of the symposium and members of their research teams. The following summary highlights the major points/topics of the meeting.
Assuntos
Química Farmacêutica/métodos , Proteínas/química , Sistemas de Liberação de Medicamentos , Desenho de Fármacos , Epigênese Genética , Relação Estrutura-Atividade , Biologia de SistemasRESUMO
Aberrant proliferation of vascular smooth muscle cells (VSMC) plays a major role in restenosis, the pathological renarrowing of the blood vessel lumen after surgical treatment of stenosis. Since available anti-proliferative pharmaceuticals produce unfavorable side effects, there is high demand for the identification of novel VSMC proliferation inhibitors. A natural product screening approach using a resazurin conversion assay enabled the identification of gentisin (1) from Gentiana lutea as a novel inhibitor of VSMC proliferation with an IC50 value of 7.84 µM. Aiming to identify further anti-proliferative compounds, 13 additional nonprenylated xanthones, isolated from different plant species, were also tested. While some compounds showed no or moderate activity at 30 µM, 1-hydroxy-2,3,4,5-tetramethoxyxanthone (4), swerchirin (6), and methylswertianin (7) showed IC50 values between 10.2 and 12.5 µM. The anti-proliferative effect of 1, 4, 6, and 7 was confirmed by the quantification of DNA synthesis (BrdU incorporation) in VSMC. Cell death quantification (determined by LDH release in the culture medium) revealed that the compounds are not cytotoxic in the investigated concentration range. In conclusion, nonprenylated xanthones are identified as novel, non-toxic VSMC proliferation inhibitors, which might contribute to the development of new therapeutic applications to combat restenosis.
Assuntos
Centaurium/química , Gentiana/química , Gentianaceae/química , Músculo Liso Vascular/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Xantonas/química , Xantonas/farmacologia , Animais , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Concentração Inibidora 50 , Estrutura Molecular , RatosRESUMO
The stereochemistry of the iridoid plumeridoid C, C(15)H(18)O(7), was established by X-ray single-crystal structure analysis, giving (2'R,3R,4R,4aS,7aR)-methyl 3-hydroxy-4'-[(S)-1-hydroxyethyl]-5'-oxo-3,4,4a,7a-tetrahydro-1H,5'H-spiro[cyclopenta[c]pyran-7,2'-furan]-4-carboxylate. The absolute structure of the title compound was determined on the basis of the Flack x parameter and Bayesian statistics on Bijvoet differences. The hydrogen-bond donor and acceptor functions of the two hydroxy groups are employed in the formation of O-H···O-bonded helical chains.
Assuntos
Apocynaceae/química , Furanos/química , Piranos/química , Compostos de Espiro/química , Cristalografia por Raios X , Ligação de Hidrogênio , Estrutura Molecular , EstereoisomerismoRESUMO
Chronic inflammation results from excessive pro-inflammatory signaling and the failure to resolve the inflammatory reaction. Lipid mediators orchestrate both the initiation and resolution of inflammation. Switching from pro-inflammatory to pro-resolving lipid mediator biosynthesis is considered as efficient strategy to relieve chronic inflammation, though drug candidates exhibiting such features are unknown. Starting from a library of Vietnamese medical plant extracts, we identified isomers of the biflavanoid 8-methylsocotrin-4'-ol from Dracaena cambodiana, which limit inflammation by targeting 5-lipoxygenase and switching the lipid mediator profile from leukotrienes to specialized pro-resolving mediators (SPM). Elucidation of the absolute configurations of 8-methylsocotrin-4'-ol revealed the 2S,γS-isomer being most active, and molecular docking studies suggest that the compound binds to an allosteric site between the 5-lipoxygenase subdomains. We identified additional subordinate targets within lipid mediator biosynthesis, including microsomal prostaglandin E2 synthase-1. Leukotriene production is efficiently suppressed in activated human neutrophils, macrophages, and blood, while the induction of SPM biosynthesis is restricted to M2 macrophages. The shift from leukotrienes to SPM was also evident in mouse peritonitis in vivo and accompanied by a substantial decrease in immune cell infiltration. In summary, we disclose a promising drug candidate that combines potent 5-lipoxygenase inhibition with the favorable reprogramming of lipid mediator profiles.