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Previous issue date: 2017-02-23 / A dengue ? uma arbovirose que afeta o homem, gerando uma problem?tica na sa?de p?blica do mundo, especialmente em pa?ses tropicais os quais apresentam condi??es que favorecem a dissemina??o do mosquito Aedes aegypti. Atualmente, dentre as v?rias estrat?gias para controle da doen?a, ainda n?o se tem uma vacina eficaz ou um antiviral capaz de combater essa infec??o. Assim, o objetivo do presente estudo foi avaliar a atividade antiviral de extratos obtidos da folha e frutos da planta Morinda citrifolia L. em cultura de c?lulas Vero infectadas com v?rus dengue-2 (DENV-2). Inicialmente foram obtidos os extratos brutos (hidroetan?lico) e as respectivas fra??es: hexano, clorof?rmio e acetato de etila, analisados por cromatografia. O teste de citotoxicidade do extrato bruto, res?duo aquoso e fra??es foram realizados em cultura de c?lulas Vero pelo m?todo MTT, nas concentra??es de 1000; 500; 250; 125; 62,5; 31,2 ?g/mL. O ensaio antiviral foi conduzido atrav?s das seguintes estrat?gias: c?lulas infectadas com DENV-2 (controle positivo); c?lulas mantidas com meio de cultura (controle negativo); c?lulas infectadas com DENV-2 e tratadas com o extrato ou fra??es. Ap?s cinco dias de infec??o a viabilidade celular foi avaliada pelo m?todo de MTT e o sobrenadante da cultura foi utilizado para quantifica??o viral por unidade formadora de placa (PFU). Os resultados demonstraram que a an?lise cromatogr?fica dos extratos e fra??es revelou bandas distintas e sugestivas de saponinas, terpenos e flavonoides. Tais extratos e fra??es n?o foram t?xicos para as culturas de c?lulas, com exce??o do tratamento das c?lulas com a fra??o clorof?rmio obtido da folha e as fra??es hexano e acetato de etila do fruto verde, levando a uma viabilidade pr?xima de 65%. No ensaio antiviral o controle positivo apresentou viabilidade celular em torno de 60% ap?s cinco dias de infec??o. No tratamento com os compostos obtidos da folha observou-se que ao adicionar a fra??o de acetato de etila ?s c?lulas infectadas, estas mantiveram uma viabilidade celular pr?ximo a 100% na concentra??o de 1000?g/mL e a 85% nas concentra??es de 500 e 250?g/mL. O tratamento com a fra??o hexano apresentou uma viabilidade superior ao controle positivo em todas as concentra??es. No entanto, na fra??o clorof?rmio, a viabilidade manteve-se elevada apenas nas concentra??es de 500 e 250?g/mL. O extrato bruto e a fra??o residual aquosa n?o demonstraram atividade antiviral. As c?lulas tratadas com o extrato e as diferentes fra??es obtidas dos frutos maduro e verde, apresentaram de um modo geral uma viabilidade celular pr?xima de 100% nas concentra??es de 500 e 1000 ?g/mL no fruto maduro e apenas 1000 ?g/mL no fruto verde, com exce??o das c?lulas que foram tratadas com a fra??o clorof?rmio, na qual n?o foi poss?vel observar nenhuma diferen?a significativa quando comparado ao controle positivo. Na quantifica??o viral observou-se que as c?lulas tratadas com as fra??es hexano e clorof?rmio obtidos da folha e tamb?m os extratos brutos obtidos dos frutos maduro e verde tiveram a??o antiviral, resultando na diminui??o total da carga viral. Finalmente, a partir desse estudo podemos identificar uma poss?vel atividade antiviral dos compostos obtidos de Morinda citrifolia contra o v?rus dengue. / Dengue is an arbovirosis which affects mankind, causing problems in the public health worldwide, especially in tropical countries which present conditions that favor the spread of the mosquito Aedes aegypti. Currently, among the various strategies to control the disease, there is no effective vaccine or antiviral capable of combating this infection. Thus, the aim of the present study was to evaluate the antiviral activity of leaf and fruit extracts of the plant Morinda citrifolia L. in Vero cells culture infected with dengue-2 virus (DENV-2). Initially, the crude extracts (hydroethanolic) and their fractions were obtained: hexane, chloroform and ethyl acetate, followed by chromatographic analysis. The cytotoxicity test of the crude extract, the aqueous residue and its fractions were performed in culture of Vero cells by the MTT method, at concentrations of 1000; 500; 250; 125; 62.5; 31.2 ?g/mL. The antiviral assay results were conducted through the following strategies: cells infected with DENV-2 (positive control); cells maintained with culture medium (negative control); cells infected with DENV-2 and treated with the extract or fractions. After five days of infection, cell viability was evaluated by the MTT method and culture supernatant was used for viral quantification by plaque forming unit (PFU) assay. The results showed that the chromatographic analysis of extracts and fractions present distinct bands, which could be suggestive of saponins, terpenes and flavonoids. Such extracts and fractions were not toxic to cell cultures, except for the cells treated with the chloroform fraction obtained from leaf, hexane and ethyl acetate fractions of the green fruit, leading to a near 65% viability. In the antiviral assay the positive control had 60% of cell viability after five days of infection. Among the leaf extract treatments, it was observed that infected cells treated with ethyl acetate fraction, maintained their cell viability around 100% in the concentration of 1000?g/mL and up to 85% in the concentrations of 500 and 250?g/mL. The hexane fraction treatment showed higher viability in comparison to the positive control at all concentrations. However, in the chloroform fraction, viability remained high only at concentrations of 500 and 250 ?g/mL. Crude extract and residual aqueous fraction did not show any antiviral activity. Cells treated with the extract and different fractions obtained from the mature and green fruits, presented an overall cell viability close to 100% in 500 and 1000 ?g/mL in the mature fruit and only 1000 ?g/mL in the green fruit. However, for the cells treated with the chloroform fraction, it was not possible to observe any significant difference when compared to the positive control. In the viral quantification it was observed that cells treated with hexane and chloroform fractions obtained from leaf, as well as crude extracts obtained from mature and green fruits had antiviral effect, resulting in a total viral load decrease. Finally, identified from this study, a possible antiviral activity of the compounds obtained from Morinda citrifolia against dengue virus.
Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/23938 |
Date | 23 February 2017 |
Creators | Moreira, Polyanna Silva |
Contributors | 69508950200, Peres, Nalu Teixeira de Aguiar, 29183976876, Andrade, V?nia Sousa, 56108150610, Farias, Kleber Juvenal Silva, Machado, Paula Renata Lima |
Publisher | PROGRAMA DE P?S-GRADUA??O EM BIOLOGIA PARASIT?RIA, UFRN, Brasil |
Source Sets | IBICT Brazilian ETDs |
Language | Portuguese |
Detected Language | English |
Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
Rights | info:eu-repo/semantics/openAccess |
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