Base de dados : LILACS
Pesquisa : D02.522.818.222 [Categoria DeCS]
Referências encontradas : 14 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 2 ir para página        

  1 / 14 LILACS  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
Id: lil-761223
Autor: Santana, DP; Ribeiro, TF; Ribeiro, EL; Aquino, GLB; Naves, PLF.
Título: Ação de chalconas contra a formação de biofilme de Candida albicans / Action of chalcones against biofilm formation of Candida albicans
Fonte: Rev. ciênc. farm. básica apl;36(1), mar. 2015. tab, graf, ilus.
Idioma: pt.
Resumo: Candida albicans é uma levedura oportunista que apresenta um conjunto de fatores de virulência que conferem uma maior patogenicidade a estes micro- organismos. Neste trabalho foram estudadas a expressão de determinados fatores de virulência de C. albicans isoladas de cavidade bucal, com ênfase na formação de biofilme, e a atividade antifúngica e o impacto de concentrações subinibitórias de derivados de chalconas na formação de biofilme por estes micro-organismos. Os compostos foram avaliados quanto à toxicidade pelo ensaio de letalidade de Artemia salina e determinação da dose letal a 50% (DL 50 ) ao micro-crustáceo. Nas chalconas sintetizadas, manteve-se o grupameno hidroxil no anel B e foram feitas modificações no anel A que resultaram em diferenças na toxicidade dos compostos variando de 714,3 a 1798,1?g/mL. As leveduras expressaram de forma variável os fatores de virulência com predomínio de alta produção de fosfolipases, aspartil proteinases e com formação do tubo germinativo em até duas horas. A formação de biofilmes foi categorizada em dois grupos distintos nos quais 16 (48%) leveduras foram consideradas como formadoras fracas e 17 (52%) como formadoras fortes. A susceptibilidade as chalconas foi > 1000?g/mL exceto para (E)-1-fenil-3-(4-hidroxifenil) prop-2-em-1-ona que apresentou uma concentração inibitória mínima de 62,5?g/mL para os isolados e de 250?g/mL para a cepa de C. albicans ATCC 10231. Entretanto, concentrações subinibitórias das chalconas apresentaram uma significativa atividade inibitória da formação de biofilme por C. albicans, com graus de inibição variando de 75 a 90%, o que indica a potencial utilização destes compostos na inibição deste importante fator de virulência.(AU)

Candida albicans is an opportunistic yeast that has a number of virulence factors that increase pathogenicity of these micro-organisms. In this study the expression of certain virulence factors were studied of C. albicans isolated from the oral cavity with emphasis on biofilm formation and antifungal activity and the impact of subinibitory concentrations of derivatives of chalconas in biofilm formation by these micro-organisms. The compounds were evaluated for toxicity testing of brine shrimp lethality and determination of 50% lethal dose (LD50) to the micro-crustacean. In synthesized chalconas, remained grouping the hydroxyl in ring B and ring modifications were made on the resulting differences in toxicity of the compounds ranging from 714.3 to 1798.1 ?g/mL. Yeasts shown variable expressed virulence factors with prevalence of high production of phospholipases, aspartyl proteases and formation of germ tube within two hours. The biofilm formation was categorized into two distinct groups in which 16 (48%) yeasts were considered as poor and 17 trainers (52%) as forming strong. Susceptibility was chalcones ? 1000 ?g/mL except for (E)-1-phenyl-3-(4-hydroxyphenyl) prop-2-en-1-one, which showed a minimum inhibitory concentration of 62.5?g/mL for the clinical isolates and 250?g/mL for the strain of C. albicans ATCC 10231. However, subinibitory concentrations of chalcones showed significant inhibitory activity of biofilm formation by C. albicans with degrees of inhibition ranging from 75 to 90%, indicating the potential use of these compounds in the inhibition of this important virulence factor.(AU)
Descritores: Candida albicans/virologia
Biofilmes
Fatores de Virulência
Chalconas
Responsável: BR33.1 - Divisão Técnica de Biblioteca e Documentação


  2 / 14 LILACS  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
Id: lil-742458
Autor: Cardoso, Claudia Andrea Lima; Salvador, Marcos José; Carvalho, João Ernesto; Coelho, Roberta Gomes.
Título: Avaliação das atividades antiproliferativa e antioxidante em frutos de Campomanesia pubescens / Evaluation of antioxidant and antiproliferative activities in fruits of Campomanesia pubescens
Fonte: Rev. Inst. Adolfo Lutz;72(4):309-315, 2013. ilus, tab.
Idioma: pt.
Resumo: A investigação química dos extratos bioativos dos frutos de Campomanesia pubescens (Myrtaceae)resultou no isolamento de duas chalconas. Os compostos isolados foram identificados pelas análises espectroscópicas (1H, 13C e 2D RMN) e, por comparação com os dados descritos na literatura. A capacidade antioxidante dos extratos e frações foi determinada utilizando-se os ensaios de capacidade de absorção de oxigênio radical (ORAC-FL) e de DPPH; e os teores de fenólicos solúveis foram medidos utilizando-seo reagente de Folin-Ciocalteau. Os efeitos antiproliferativos dos extratos e de isolados de chalconas 1 e2 foram determinados in vitro contra as seguintes células cancerosas humanas U251 (glioma), UACC-62 (melanoma), MCF-7 (mama), NC1-ADR/RES (ovário resistente), 786,0 (rim), NCI-H460 (pulmão),PC-3 (próstata), OVCAR-3 (ovário), HT-29 (cólon) e K562 (leucemia), e contra linhagem celular não cancerígena VERO. O extrato hexânico e os compostos isolados de chalconas 1 e 2 demonstraram efeito antiproliferativo potente contra linhagens de células cancerosas com valores de inibição de crescimento total (TGI) menores dos aqueles observados na linhagem celular controle. A atividade mais elevada das chalconas 1 e 2 foi detectada nas células MCF-7, PC-3 e HT-29.

Chemical investigation on the bioactive extracts from fruits of Campomanesia pubescens (Myrtaceae)resulted in the isolation of two chalcones. The isolated compounds were identified by means of spectroscopicanalysis (1H, 13C and 2D NMR), and by comparing with the data reported in the specific literature.Antioxidant capacity of extracts and fractions was determined using the oxygen radical absorbancecapacity (ORAC-FL) and DPPH assays; and the total soluble phenolic contents were measured by usingFolin-Ciocalteau reagent. The anti-proliferative effects of the extracts and of the chalcone isolates 1 and2 were determined in vitro against human cancer cells lineages U251 (glioma), UACC-62 (melanoma),MCF-7 (breast), NC1-ADR/RES (ovarian-resistant), 786.0 (kidney), NCI-H460 (lung), PC-3 (prostate),OVCAR-3 (ovarian), HT-29 (colon) and K562 (leukemia), and against non-cancerous cell line VERO.Hexanic extract and chalcone isolated compounds 1 and 2 showed potent antiproliferative effect againstcancer cell lineages with lower total growth inhibition (TGI) values than those found in control cell line.The highest activity of the chalcones 1 and 2 was observed against the MCF-7, PC-3 and HT-29 cell lines.
Descritores: Antioxidantes/análise
Chalconas
Compostos Fenólicos/análise
Frutas/química
Myrtaceae/química
Neoplasias/terapia
Responsável: BR91.2 - Centro de Documentação


  3 / 14 LILACS  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo SciELO Brasil
Sinhoreti, Mário Alexandre Coelho
Texto completo
Id: biblio-841154
Autor: OLIVEIRA, Dayane Carvalho Ramos Salles de; SOUZA-JUNIOR, Eduardo José; DOBSON, Adam; CORRER, Ana Rosa Costa; BRANDT, William Cunha; SINHORETI, Mário Alexandre Coelho.
Título: Evaluation of phenyl-propanedione on yellowing and chemical-mechanical properties of experimental dental resin-based materials
Fonte: J. appl. oral sci;24(6):555-560, Nov.-Dec. 2016. tab, graf.
Idioma: en.
Projeto: São Paulo Research Foundation.
Resumo: ABSTRACT Objective To evaluate the influence of phenyl-propanedione on yellowing and chemical-mechanical properties of experimental resin-based materials photoactivated using different light curing units (LCUs). Material and Methods Experimental resin-based materials with the same organic matrix (60:40 wt% BisGMA:TEGDMA) were mechanically blended using a centrifugal mixing device. To this blend, different photoinitiator systems were added in equimolar concentrations with aliphatic amine doubled by wt%: 0.4 wt% CQ; 0.38 wt% PPD; or 0.2 wt% CQ and 0.19 wt% PPD. The degree of conversion (DC), flexural strength (FS), Young’s modulus (YM), Knoop hardness (KNH), crosslinking density (CLD), and yellowing (Y) were evaluated (n=10). All samples were light cured with the following LCUs: a halogen lamp (XL 2500), a monowave LED (Radii), or a polywave LED (Valo) with 16 J/cm2. The results were analysed by two-way ANOVA and Tukey’s test (α=0.05). Results No statistical differences were found between the different photoinitiator systems to KNH, CLS, FS, and YM properties (p≥0.05). PPD/CQ association showed the higher DC values compared with CQ and PPD isolated systems when photoactivated by a polywave LED (p≤0.05). Y values were highest for the CQ compared with the PPD systems (p≤0.05). Conclusion PPD isolated system promoted similar chemical and mechanical properties and less yellowing compared with the CQ isolated system, regardless of the LCU used.
Descritores: Polietilenoglicóis/química
Ácidos Polimetacrílicos/química
Bis-Fenol A-Glicidil Metacrilato/química
Chalconas/química
Cura Luminosa de Adesivos Dentários/métodos
Fotoiniciadores Dentários/química
-Espectrofotometria
Teste de Materiais
Cânfora/análogos & derivados
Cânfora/química
Reprodutibilidade dos Testes
Espectroscopia de Infravermelho com Transformada de Fourier
Pigmentação em Prótese
Cor
Estatísticas não Paramétricas
Maleabilidade
Transição de Fase
Luzes de Cura Dentária
Módulo de Elasticidade
Polimerização
Testes de Dureza
Tipo de Publ: Estudo Comparativo
Estudo de Avaliação
Responsável: BR1.1 - BIREME


  4 / 14 LILACS  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo SciELO Brasil
Texto completo
Texto completo
Id: biblio-974391
Autor: Díaz-Carrillo, José Tomás; Díaz-Camacho, Sylvia Páz; Delgado-Vargas, Francisco; Rivero, Ignacio Alfredo; López-Angulo, Gabriela; Sarmiento-Sánchez, Juan Ignacio; Montes-Avila, Julio.
Título: Synthesis of leading chalcones with high antiparasitic, against Hymenolepis nana, and antioxidant activities
Fonte: Braz. J. Pharm. Sci. (Online);54(3):e17343, 2018. tab, graf.
Idioma: en.
Resumo: The hymenolepiosis by Hymenolepis nana is a major public health problem in developing countries, and the commercial drugs against this parasitosis are not enough effective. The combination of antiparasitic and antioxidant agents has improved the treatment of some parasitoses. Thus, the development of new cestocidal and antioxidant agents to treat the hymenolepiosis cases is important. In the present study, four hydroxy- and four dihydroxy-chalcones were synthesized using the catalyst boron trifluoride diethyl etherate (BF3•OEt2). The antioxidant activity and antiparasitic against H. nana of chalcones were tested, as well as the toxicity by the brine shrimp lethality bioassay and the method of Lorke. The antioxidant activity was measured by three radical scavenging assays: 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP). The hydroxyl substitution pattern (number and position), mainly in ring B, was responsible for the chalcone antiparasitic activity. At least one meta or para hydroxyl group in ring B was essential for activity of the synthetic chalcones against H. nana; The time taken for the parasite to die by the 3b and 3e chalcones (20 mg/mL) treatment was up to six times lower than the control drug Praziquantel. On the other hand, chalcones with catechol structure in ring B (3g and 3h) showed the highest antioxidant values. The toxicity evaluations suggests that synthetic hydroxychalcones with cestocidal (3b and 3e) and antioxidant (3g and 3h) activities are safe compounds and potential in vivo agents to treat this parasitosis
Descritores: Doenças Parasitárias/tratamento farmacológico
Hymenolepis nana/imunologia
Chalconas/administração & dosagem
-Antioxidantes/efeitos adversos
Antiparasitários/efeitos adversos
Responsável: BR1.1 - BIREME


  5 / 14 LILACS  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Alves, Eduardo
Texto completo
Texto completo
Id: biblio-965789
Autor: Camargos, Renato Barbosa; Perina, Fabiano José; Carvalho, Daniel Diego Costa; Alves, Eduardo; Mascarello, Alessandra; Chiaradia-Delatorre, Louise Domeneghini; Yunes, Rosendo Augusto; Nunes, Ricardo José; Oliveira, Denilson Ferreira.
Título: Chalcones to control Alternaria alternata in murcott tangor fruits / Chalconas no controle de Alternaria alternata em frutos de tangor murcote
Fonte: Biosci. j. (Online);32(6):1512-1521, nov./dec. 2016. ilus, tab.
Idioma: en.
Resumo: Alternaria brown spot (ABS), caused by the fungus Alternaria alternata pathotype tangerine, is one of the main phytosanitary problems for mandarin growers. About 15 applications per year of harmful fungicides are required for controlling ABS disease in citrus orchards. As chalcones seem to be less toxic to humans and environment than the commercial fungicides in use, this study initially aimed at synthesizing 137 chalcones through aldolic condensations between benzaldehydes and acetophenones. The resulting chalcones were screened for activity against A. alternata through a fungal growth assay that was carried out in 96-cell polypropylene plates, using the same concentration to all studied substances. The four active chalcones underwent conidia germination and mycelial growth, which confirmed the antifungal activity of the compounds. These chalcones were then poured onto Murcott tangor fruit that had been inoculated with conidia of the fungus. All four chalcones reduced the ABS progress to values significantly smaller (P0.05) than that observed for the control. Statistical calculations showed that the best results were afforded by two compounds, bearing a 2,4,5-trimethoxyphenyl group at position 3 of prop-2-enal and a 3-nitro- or 3-hydroxyphenyl group at position 1 of the aldehyde. Such compounds reduced the incidence of the disease in Murcott tangor fruit to values that did not differ statistically from those obtained with a commercial fungicide.

A mancha marron de Alternaria (MMA), causada pelo fungo Alternaria alternata patótipo tangerina, é um dos maiores problemas fitossanitários dos produtores de tangerina. Aproximadamente 15 aplicações de fungicidas de elevada periculosidade, por ano, são necessárias para o controle de MMA em várias plantações de citros. Como as chalconas parecem menos tóxicas para os seres humanos e para o ambiente que os fungicidas comerciais atualmente em uso, este estudo teve como objetivo inicial sintetizar 137 chalconas através da condensação aldólica de benzaldeídos com acetofenonas. As atividades das chalconas resultantes contra A. alternata foram avaliadas através do emprego de teste de crescimento fúngico em placas de polipropileno com 96 cavidades, empregando a mesma concentração para todas as substâncias estudadas. As quatro chalconas mais ativas foram submetidas a testes de germinação de conídios e de crescimento micelial, que confirmaram as atividades antifúngicas dos compostos selecionados. Estes foram então, aplicados em frutos de tangor Murcote que tinham sido inoculados com conídios do fungo. Todas as quatro chalconas reduziram o progresso de MMA a valores significativamente inferiores (P0.05) ao observado para o controle. Cálculos estatísticos mostraram que os melhores resultados foram obtidos para dois compostos, que tinham um grupo 2,4,5-trimetoxifenil na posição 3 do prop-2-enal e um grupo 3-nitro- ou 3-hidroxifenil na posição 1 do aldeído. Tais compostos reduziram a incidência da doença em frutos de tangor Murcote a valores que não diferiam estatisticamente do obtido com um fungicida comercial.
Descritores: Citrus
Chalconas
Alternaria
Fungicidas Industriais
Responsável: BR396.1 - Biblioteca Central


  6 / 14 LILACS  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
Id: biblio-998821
Autor: Ortolan, Xana Raquel; Mezadri, Telmo José; Tames, David Rivero; Corrêa, Rogério; Campos-Buzzi, Fátima.
Título: Osteogenic potential of different chalcones in an in vivo model: a preliminary study
Fonte: J. oral res. (Impresa);6(8):209-215, ago. 2017. ilus, tab, graf.
Idioma: en.
Resumo: Aim. To evaluate the osteogenic potential of chalcones using the rat critical size calvarial defect. Methods. The chalcones were synthesized from acetophenone following the Claisen-Schmidt aldol condensation method by varying the substituted benzaldehydes (3,4-Cl; 4-Cl; 4-CH3; 4-OCH3, H). The five chalcone molecules were evaluated in three concentrations (1 percent, 5 percent and 10 percent) in comparison to control and vehicle (Vaseline) groups. The results of the remaining wound areas were calculated statistically by the ANOVA method followed by the Student-Newman-Keuls test and the histological sections were analyzed qualitatively by light microscopy. Results. All molecules at 10 percent concentration showed significant bone closure compared to the control, vehicle and chalcone groups at 1 percent concentration (p<0.01). Active osteoblasts were observed on the repair surfaces in all groups treated with chalcones. Treatment with the C5 molecule at concentration of a 10 percent resulted in greater bone neoformation compared to the other molecules, with features of secondary bone observed. Conclusion. The chalcones evidenced a dose-dependent osteogenic potential and C5 was more effective in bone repair
Descritores: Osteogênese
Chalconas/síntese química
-Ratos Wistar
Limites: Animais
Feminino
Ratos
Responsável: CL1.1 - Biblioteca Central


  7 / 14 LILACS  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
Id: biblio-907655
Autor: Barrera M., Francisco.
Título: Nuevas estrategias farmacológicas para el tratamiento del hígado graso no alcohólico / New pharmacological strategies for the treatment of non-alcoholic fatty liver disease
Fonte: Gastroenterol. latinoam;27(supl.1):S55-S59, 2016. ilus, tab, graf.
Idioma: es.
Resumo: Non-alcoholic fatty liver disease (NAFLD) represents an increasing health problem in Chile and worldwide. In some cases NAFLD presents with a progressive form that can lead to liver fibrosis, cirrhosis and hepatocellular carcinoma. Current pharmacological therapies (pioglitazone and vitamin E) show limited response and are associated to significant adverse effects. During recent years several novel and promising pharmacological therapies have been developed to prevent fibrosis, liver cirrhosis and reduce liver related deaths. The present article summarizes some of these promising strategies, including reported efficacy in clinical trials and associated adverse effects. Hopefully in the near future these new therapies will help to improve NAFLD management and reduce liver related complications.

El hígado graso no alcohólico (HGNA) es un creciente problema de salud pública en Chile y el mundo. En un subgrupo de sujetos, el HGNA puede presentarse con un fenotipo de daño hepático progresivo que puede evolucionar a fibrosis progresiva, cirrosis y carcinoma hepatocelular. Las estrategias farmacológicas actuales (pioglitazona y vitamina E) presentan eficacia limitada y no están exentas de efectos adversos. Durante los últimos años se han desarrollado múltiples estrategias farmacológicas novedosas y promisorias que buscan evitar la progresión hacia cirrosis y reducir la mortalidad de causa hepática. El presente artículo resume los principales nuevos fármacos, los efectos beneficiosos reportados y sus efectos adversos. Es de esperar que en un futuro próximo estas terapias permitan cambiar el pronóstico de nuestros pacientes con HGNA.
Descritores: Ácido Quenodesoxicólico/análogos & derivados
Ácido Quenodesoxicólico/uso terapêutico
Liraglutida/uso terapêutico
Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico
Propionatos/uso terapêutico
-Chalconas/uso terapêutico
Cirrose Hepática/prevenção & controle
Limites: Humanos
Responsável: CL61.1 - Biblioteca Central Campus Sur


  8 / 14 LILACS  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
Id: lil-795821
Autor: Kubínová, Renata; Pořízková, Radka; Bartl, Tomás; Navrátilová, Alice; Čízek, Alois; Valentová, Marie.
Título: Biological activities of polyphenols from Polygonum lapathifolium / Actividades biológicas de polifenoles de Polygonum lapathifolium
Fonte: Bol. latinoam. Caribe plantas med. aromát;13(6):506-516, nov.2014. ilus, tab.
Idioma: en.
Projeto: IGA VFU.
Resumo: Polygonum lapathifolium is an invasive plant spread worldwide, which has been used in traditional medicine for its biological activities. We studied chemical profile of the aerial part using HPLC/DAD/ESI-MS. Eight flavonoids, two chalcones and gallic acid were isolated, identified nad tested for their activity in seven experimental models (for antioxidant, alpha/beta-glucosidase inhibitory, antimicrobial, anticholineserase activity). Our results showed that P. lapathifolium is a valuable source of compounds with perspective biological activities...

Polygonum lapathifolium es una planta invasora cuya presencia se extiende por todo el mundo y que ha sido utilizada en la medicina tradicional por sus actividades biológicas. Analizamos el perfil químico de la parte superficial utilizando HPLC/DAD/ESI-MS. Ocho flavonoides, dos chalconas y ácido gálico fueron aislados, identificados y analizados en relación a sus actividades en siete modelos experimentales (de actividad antioxidante, alfa/beta-glucosidasa inhibitoria, antimicrobiana, anticholineserasa). Nuestros resultados demuestran que P. lapathifolium es una valiosa fuente de compuestos con actividades biológicas prometedoras...
Descritores: Antioxidantes/farmacologia
Extratos Vegetais/farmacologia
Flavonoides/análise
Polygonum/química
-Anti-Infecciosos
Cromatografia Líquida de Alta Pressão
Chalconas/análise
Inibidores Enzimáticos/farmacologia
Polifenóis/análise
Espectrometria de Massas por Ionização por Electrospray
Responsável: CL1.1 - Biblioteca Central


  9 / 14 LILACS  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
Id: lil-712428
Autor: Mora, Cristina Lucía; Castaño, Julián; Jaramillo, María Consuelo.
Título: Actividad inhibitoria de dihidroxifenil propenona sobre betalactamasas de Enterobacter cloacae: estudio preliminar en el desarrollo de fármacos para enfrentar la resistencia bacteriana / Inhibitory activity of dihydroxy-phenyl-propenone on betalactamase of Enterobacter cloacae : Preliminary study for drug development to overcome bacterial resistance
Fonte: Biomédica (Bogotá);34(supl.1):114-123, abr. 2014. ilus, graf, tab.
Idioma: es.
Resumo: Introducción . Los microorganismos patógenos como Enterobacter cloacae producen betalactamasas que les confieren resistencia frente a los antibióticos betalactámicos; se ha identificado, además, la actividad limitada de los inhibidores enzimáticos, de modo que la única posibilidad de enfrentar la resistencia es el diseño de nuevos fármacos y su uso racional. Objetivo. Evaluar el efecto de la chalcona dihidroxifenil propenona sobre un aislamiento clínico de E. cloacae y sobre la betalactamasa aislada a partir de este microorganismo resistente como un aporte en la búsqueda de compuestos inhibidores de las betalactamasas. Materiales y métodos. Se sintetizó la chalcona dihidroxifenil propenona y se evaluó su efecto sobre el aislamiento clínico de E. cloacae para determinar la concentración inhibitoria mínima mediante el método de microdilución en caldo y con la betalactamasa purificada mediante cromatografía de afinidad se realizaron estudios espectrofotométricos de cinética enzimática. Resultados. La concentración inhibitoria mínima de la dihidroxifenil propenona sobre E. cloacae fue de 35 µg/ml; el porcentaje de recuperación de la betalactamasa a partir del microorganismo fue de 31,75 %; en el estudio cinético se evidenció actividad inhibitoria de acuerdo con los parámetros cinéticos de V max =1,7 x 10 -3 µM/minuto y K M´ =2330 µM. Conclusión. La chalcona dihidroxifenil propenona ejerce su actividad inhibitoria por medio de la interacción con la betalactamasa y, de esta manera, protege la integridad estructural de los antibióticos betalactámicos; dicho efecto sinérgico la convierte en un compuesto promisorio en la búsqueda de alternativas para enfrentar la resistencia bacteriana.

Introduction: Enterobacter cloacae is a pathogenic microorganism with the ability to produce betalactamase enzymes, which makes them resistant to betalactamic antibiotics. Additionally, the limited activity of enzymatic inhibitors has been identified, and, therefore, the design of new drugs and the promotion of their rational use are the only possibilities to overcome this problem. Objective: The aim of this research was to evaluate the effect of dihydroxy-phenyl-propenone on a clinical isolate of E. cloacae , as well as its activity on a betalactamase isolated from this resistant microorganism in order to contribute to the search for new betalactamase inhibitors. Materials and methods: Dihydroxy-phenyl-propenone chalcone was synthesized and evaluated on a clinical isolate of E. cloacae to determine the minimum inhibitory concentration by broth microdilution; once the betalactamase enzyme was purified by affinity chromatography, a spectrophotometric analysis was done to evaluate its kinetic activity. Results: The minimum inhibitory concentration value of dihydroxy-phenyl-propenone on E. cloacae was 35 µg/ml; the recovery percentage of the betalactamase from the microorganism was 31.75% and the kinetic parameters were V max =1.7 x 10 -3 µM/min and K M = 2330 µM, which show an important inhibitory activity. Conclusion: Dihydroxy-phenyl-propenone has shown inhibitory activity on betalactamase enzymes and the ability to protect the chemical integrity of betalactamic antibiotics; this synergistic effect turns it into a promising compound in the search for new alternatives to overcome bacterial resistance.
Descritores: Proteínas de Bactérias/antagonistas & inibidores
Chalconas/farmacologia
Enterobacter cloacae/efeitos dos fármacos
Penicilinase/metabolismo
Resistência beta-Lactâmica/efeitos dos fármacos
Inibidores de beta-Lactamases/farmacologia
-Ampicilina/farmacologia
Proteínas de Bactérias/isolamento & purificação
Proteínas de Bactérias/metabolismo
Cromatografia de Afinidade
Contagem de Colônia Microbiana
Colorimetria
Chalconas/química
Chalconas/síntese química
Avaliação Pré-Clínica de Medicamentos
Sinergismo Farmacológico
Enterobacter cloacae/enzimologia
Infecções por Enterobacteriaceae/microbiologia
Testes de Sensibilidade Microbiana
Estrutura Molecular
Ácido Penicilânico/análogos & derivados
Ácido Penicilânico/antagonistas & inibidores
Penicilinase/isolamento & purificação
Inibidores de beta-Lactamases/química
Inibidores de beta-Lactamases/síntese química
Limites: Humanos
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: CO332 - Facultad de Medicina


  10 / 14 LILACS  
              first record previous record
seleciona
para imprimir
Fotocópia
Texto completo SciELO Brasil
Texto completo
Id: lil-709487
Autor: Bozic, Dragana D.; Milenkovic, Marina; Ivkovic, Branka; Cirkovic, Ivana.
Título: Newly-synthesized chalcones-inhibition of adherence and biofilm formation of methicillin-resistant Staphylococcus aureus
Fonte: Braz. j. microbiol;45(1):263-270, 2014. tab.
Idioma: en.
Projeto: Republic of Serbia. Ministry of Science.
Resumo: Biofilm formation and adherence of bacteria to host tissue are one of the most important virulence factors of methicillin-resistant strains of Staphylococcus aureus (MRSA). The number of resistant strains is seriously increasing during the past years and bacteria have become resistant, not only to methicillin, but also to other commonly used antistaphylococcal antibiotics. There is a great need for discovering a novel antimicrobial agent for the treatment of staphylococcal infections. One of the most promising groups of compounds appears to be chalcones. In present study we evaluated the in vitro effect of three newly synthesized chalcones: 1,3-Bis-(2-hydroxy-phenyl)-propenone, 3-(3Hydroxy-phenyl)-1-(2-hydroxy-phenyl)-propenone and 3-(4-Hydroxy-phenyl)-1-(2-hydroxyphenyl)-propenone on glycocalyx production, biofilm formation and adherence to human fibronectin of clinical isolates and laboratory control strain of MRSA (ATCC 43300). Subinhibitory concentrations of the tested compounds reduced the production of glycocalyx, biofilm formation and adherence to human fibronectin of all MRSA strains. Inhibition of biofilm formation was dose dependent and the most effective was 1,3-Bis-(2-hydroxy-phenyl)-propenone. In our study we demonstrated that three newly-synthesized chalcones exhibited significant effect on adherence and biofilm formation of MRSA strains. Chalcones may be considered as promising new antimicrobial agents that can be used for prevention of staphylococcal infections or as adjunct to antibiotics in conventional therapy.
Descritores: Antibacterianos/farmacologia
Biofilmes/efeitos dos fármacos
Chalconas/farmacologia
Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos
-Antibacterianos/síntese química
Aderência Bacteriana/efeitos dos fármacos
Biofilmes/crescimento & desenvolvimento
Chalconas/síntese química
Relação Dose-Resposta a Droga
Fibronectinas/metabolismo
Glicocálix/metabolismo
Staphylococcus aureus Resistente à Meticilina/isolamento & purificação
Staphylococcus aureus Resistente à Meticilina/fisiologia
Relação Estrutura-Atividade
Infecções Estafilocócicas/microbiologia
Limites: Humanos
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: BR1.1 - BIREME



página 1 de 2 ir para página        
   


Refinar a pesquisa
  Base de dados : Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde