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Previous issue date: 2016 === Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) === Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG ) === Nos ?ltimos anos, um n?mero crescente de pesquisas tem demonstrado o papel chave das esp?cies reativas (ERs) na acelera??o do processo de envelhecimento e agravamento de doen?as inflamat?rias e cr?nico-degenerativas. Tais esp?cies, altamente reativas, podem oxidar v?rias biomol?culas e provocar graves les?es no organismo. O efeito das ERs ? equilibrado no organismo por a??o de antioxidantes enzim?ticos e n?o enzim?ticos, sendo estes ?ltimos, representados em sua maioria pelos compostos fen?licos, sendo os flavon?ides os principais representantes. Os flavon?ides podem ser consumidos na dieta di?ria atrav?s de v?rios alimentos como frutas, legumes, vinhos etc., por?m, o principal alvo para busca de tais compostos s?o as plantas medicinais que s?o constantemente utilizadas pela popula??o. Tendo em vista a import?ncia de desenvolvimento e busca de novos compostos antioxidantes naturais, o presente estudo teve como principal objetivo avaliar a atividade antioxidante dos extratos etan?licos de algumas esp?cies vegetais que v?m sendo utilizadas na medicina popular, dentre outras finalidades, como antiinflamat?rias, cicatrizantes e outros usos relacionados a atividade antioxidante. As esp?cies vegetais utilizadas foram: Ageratum fastigiatum (GARDN.) R. M. KING et H. ROB., Croton antisyphiliticus MART., Kielmeyera rubriflora CAMB., Miconia ferruginata DC., e Norantea adamantium CAMB., coletadas no munic?pio de Diamantina ? MG e regi?es subjacentes, ?reas de predomin?ncia do bioma Cerrado. Avaliando a atividade antioxidante e teor de fen?licos totais (FT) nos extratos, pode-se observar que todos os extratos, exceto da A. fastigiatum (partes a?reas) apresentaram altos teores de compostos fen?licos, determinado pelo m?todo colorim?trico de Folin-Ciocalteau (FC) e eficiente poder redutor (PR), com destaque para a N. adamantium (partes a?reas), que apresentou o maior teor de FT (684,59 mg EAG/g extrato) e o menor valor para o PR (EC50 = 66,77 ?g/mL). Quanto ? captura das esp?cies radicalares DPPH? e ABTS?+, os extratos seguiram uma correla??o positiva, determinada pelo coeficiente de Pearson, ou seja, os extratos com maiores teores de FT tamb?m apresentaram as melhores atividades de captura das esp?cies radicalares com destaque para a N. adamantium (partes a?reas) e C. antisyphiliticus (caule) que apresentaram resultados de EC50 estatisticamente semelhantes ao padr?o ?cido g?lico (AG) para a captura de ambas as esp?cies radicalares utilizadas. Para a captura dos reagentes HOCl e H2O2 todos os extratos foram eficientes, por?m apresentaram melhores resultados apenas em altas concentra??es (>100?g/mL), sendo necess?rio um estudo de citotoxicidade para avaliar se tais concentra??es n?o s?o t?xicas ?s c?lulas humanas. Por fim, foi realizada uma avalia??o de interfer?ncia dos extratos no burst oxidativo produzidos por neutr?filos humanos isolados ativados com PMA e todos os extratos apresentaram atividade protetora frente ?s esp?cies produzidas pelo burst oxidativo com destaque para C. antisyphiliticus (caule) e A. fastigiatum (partes a?reas) que apresentaram menores valores de EC50, igual a 8,51 e 5,74 ?g/mL respectivamente. === Disserta??o (Mestrado) ? Programa de P?s-gradua??o em Ci?ncias Farmac?uticas, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. === An increasing number of studies have been lately demonstrating the key role of the reactive species (RS) in accelerating aging and worsening inflammatory and chronic-degenerative diseases. This species, highly reactive, are able to oxidize several biomolecules and cause severe injuries to the organism. The effect of the RS is balanced by the enzymatic and non-enzymatic antioxidants, the latter being represented mostly by phenolic compounds and flavonoids key players which can be daily consumed in fruits, vegetables, wine etc. However, the main samples to search for these compounds are the medicinal plants extensively used by the population. Considering the importance of the development and screening of new natural antioxidant compounds, the present study aimed to evaluate the antioxidant activity of the ethanolic extracts of some species of plants that have been used in the popular medicine for its anti-inflammatory, healing and other uses related to antioxidant activity, among other features. The plants were: Ageratum fastigiatum (GARDN.); R. M. KING and H. ROB., Croton antisyphiliticus MART., Kielmeyera rubriflora CAMB., Miconia ferruginata DC., and Norantea adamantium CAMB., colleted at the municipality of Diamantina - MG and surroundings, where the biome Cerrado is predominant. The analysis of the antioxidant activity and the total phenolic content (TP) of the extracts showed that, except for the A. fastigiatum (aerial parts), all of the others presented high contents of phenolic compounds through the colorimetric assay of Folin-Ciocalteau (FC) and the effectiveness of the reductive power (RP). Highlights here to N. adamantium (aerial parts) extract which demonstrated the highest content of TP (684,59 mg EAG/g extract) and the lowest value of RP (EC50 = 66,77 ?g/mL). Regarding the capture of the following free radicals, DPPH? and ABTS?+, the extracts demonstrated a positive correlation, determined by the Pearson factor, which means that the extracts with the highest contents of TP also displayed better capture activities of those free radicals. It is important to emphasize N. adamantium (aerial parts) and C. antisyphiliticus (stem), once they presented statistically similar EC50 to the garlic acid (GA) for the capture of both of the free radicals used. For the capture of HOCl and H2O2, all the extracts showed to be efficient, nevertheless they presented better results only in high concentrations (>100?g/mL). Therefore it is relevant to perform a citotoxicity assay on human cells. At last, the interference of the extracts was evaluated on the oxidative burst produced by human neutrophils isolated and activated with PMA and all of them showed to be protective against the free radicals produced in the assay, in which C. antisyphiliticus (stem) and A. fastigiatum (aerial parts) standout for the lowest EC50, 8,51 and 5,74 ?g/mL respectively.
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