%0 Journal Article
%T Atividade antibacteriana in vitro de quatro esp谷cies vegetais em diferentes gradua  es alco車licas In vitro antibacterial activity of four plant species at different alcoholic contents
%A G.S. Miranda
%A G.S. Santana
%A B.B. Machado
%A F.P. Coelho
%J Revista Brasileira de Plantas Medicinais
%D 2013
%I UNESP
%X Neste trabalho foi realizada a caracteriza  o fitoqu赤mica e avaliada a atividade antibacteriana in vitro dos extratos de Ageratum conyzoides L. (mentrasto), Gossypium hirsutum (algod o), Phyllanthus tenellus (quebra pedra), e Polygonum hydropiperoides (erva de bicho) frente 角 Staphylococcus aureus e Escherichia coli. Para a avalia  o da atividade antibacteriana foi utilizado o m谷todo de difus o em 芍gar. Os testes foram realizados com o extrato nas gradua  es alco車licas de 0 a 100% (v/v), na propor  o de 20% (m/v - massa/extrator). Os testes fitoqu赤micos constataram a presen a de a ucares redutores, compostos fen車licos, flavonoides, taninos, triterpenos, e ester車ides nas quatro esp谷cies. O crescimento das culturas de S. aureus foi inibido por todos os extratos, com exce  o do extrato de Mentrasto. A maior atividade de inibi  o foi observada pelo extrato de quebra pedra. Entretanto, nenhum dos extratos foi capaz de inibir o crescimento das cepas de E. coli. Os resultados s o promissores, visto que tr那s das quatro plantas selecionadas demonstraram possuir substancias antibacterianas, o que motiva estudos subsequentes para o isolamento e identifica  o dos princ赤pios ativos respons芍veis por essa atividade, com potencial de uso na ind迆stria farmac那utica. In this study, phytochemical characterization was conducted and the in vitro antibacterial activity of extracts of Ageratum conyzoides L. (whiteweed), Gossypium hirsutum (cotton), Phyllanthus tenellus (shatterstone) and Polygonum hydropiperoides (swamp smartweed) was evaluated against Staphylococcus aureus and Escherichia coli. To assess the antibacterial activity, the agar diffusion method was used. Tests were performed with the extract at alcoholic contents from 0 to 100% (v/v), at 20% proportion (m/v - mass/extractor). Phytochemical tests indicated the presence of reducing sugars, phenolic compounds, flavonoids, tannins, triterpenes and steroids in all four species. The growth of S. aureus cultures was inhibited by all extracts, except for whiteweed extract. The highest inhibitory activity was observed for shatterstone. However, none of the extracts was capable of inhibiting the growth of E. coli strains. Results are promising since three of the four selected plants showed to have antibacterial substances, which stimulates further studies for the isolation and the identification of active principles responsible for this activity, with potential to be used in the pharmaceutical industry.
%K Fitoterapia
%K Escherichia coli
%K Staphylococcus aureus
%K Phytotherapy
%K Escherichia coli
%K Staphylococcus aureus
%U http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-05722013000100015