Jornal Brasileiro de Patologia e Medicina Laboratorial (Jun 2010)
Estudo in vitro da ação antimicrobiana de extratos de plantas contra Enterococcus faecalis In vitro antimicrobial activity of plant extracts against Enterococcus faecalis
Abstract
INTRODUÇÃO: Muitos estudos têm sido realizados para avaliar o potencial terapêutico das plantas. OBJETIVO: Este estudo teve como objetivo avaliar a ação antimicrobiana dos extratos etanólicos da aroeira-da-praia (Schinus terebinthifolius Raddi), da aroeira-do-sertão (Astronium urundeuva [Fr. All.] Engl.), da ameixa-do-mato (Ximenia americana L.), da quixabeira (Syderoxylum obtusifolium [Roem et Schult.]) e do hipoclorito de sódio (NaOCl a 2,5%), contra o Enterococcus faecalis (ATCC 29212). METODOLOGIA: Foi realizado teste de difusão em ágar, pelo método do poço, utilizando-se como controle positivo a clorexidina a 0,12%. Os microrganismos foram semeados em caldo BHI e incubados a 37ºC por 24 horas. Posteriormente, as suspensões microbianas foram semeadas em placas Petri, com ágar Mueller Hinton, sendo confeccionados seis poços equidistantes. As placas foram mantidas à temperatura ambiente por 2 horas, para ocorrer a pré-difusão das substâncias, e incubadas a 37ºC por 48 horas. Foram feitas as análises e medições dos halos de inibição em triplicata e os resultados foram analisados estatisticamente (teste de análise de variância [ANOVA]). RESULTADOS: A quixabeira apresentou os menores halos de inibição (teste t, p INTRODUCTION: Several studies have evaluated the therapeutic benefits of plants. OBJECTIVE: The aim of this study was to evaluate the antimicrobial activity of ethanol extracts of pepper tree (Schinus terebinthifolius Raddi), aroeira (Astronium urundeuva [Fr. All.] Engl.), Olacaceae (Ximenia americana L.), quixaba (Syderoxylum obtusifolium [Roem et Schult.]), and sodium hypochlorite (NaOCl 2.5%) against Enterococcus faecalis (ATCC 29212). METHODS: The agar diffusion test was performed and 0.12% chlorhexidine was applied as positive control. The microorganisms were allowed to grow in a brain-heart infusion broth (BHI) and incubated at 37ºC for 24 hours. Subsequently, the microbial suspensions were seeded on Petri dishes containing Mueller Hinton agar, and six equidistant wells were made. The plates were kept at room temperature for 2 hours for the pre-diffusion of substances, and incubated at 37ºC for 48 hours. The analysis and measurement of inhibition zones were performed in triplicate, and the results were statistically analyzed (ANOVA test). RESULTS: Quixaba produced the smallest inhibition zones (t test, p < 0.05). On the other hand, 0.12% chlorhexidine, herbal extracts of pepper tree and aroeira at 100% concentration induced larger inhibition zones in comparison with 2.5% NaOCl, with statistically significant difference (t test, p < 0.05). At all concentrations, both pepper tree and aroeira showed a higher inhibition zone against Enterococcus faecalis in comparison with the other plant extracts tested. CONCLUSION: All the substances analyzed showed antimicrobial activity against E. faecalis. Therefore , they may represent alternative substances in endodontic treatment.
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