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Avaliação da atividade antimicrobiana de plantas do serrado brasileiro sobre espiroquetas do complexo Borrelia burgdorferi sensu lato (s.l.)
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A Borreliose de Lyme (BL) é uma doença infeciosa e multissistémica causada por bactérias (espiroquetas) do complexo Borrelia burgdorferi sensu lato (B. burgdorferi s.l.), transmitidas por vetores (carraças), sobretudo da espécie Ixodes ricinus, no continente Europeu. A doença apresenta uma distribuição mundial, sendo mais prevalente nos Estados Unidos da América e na Europa. Em Portugal, é considerada uma doença de declaração obrigatória (DDO), desde 1999. A doença pode afetar
diferentes órgãos e sistemas, dependendo da espécie infetante, uma vez que cada uma possui um tropismo diferente, podendo causar desde manifestações cutâneas a complicações neurológicas. Para o seu tratamento são usados antimicrobianos como a doxiciclina, amoxicilina e ceftriaxona. No entanto, têm vindo a ser investigados novos compostos baseados em extratos de plantas, como alternativa terapêutica, de forma a
reduzir os efeitos nefastos que podem advir da utilização a longo prazo destes antimicrobianos. O Brasil é conhecido por possuir uma riquíssima biodiversidade, cujos compostos bioativos oriundos da sua flora, têm sido utilizados no tratamento de diversas doenças.
Assim, o principal objetivo deste trabalho foi investigar a atividade antimicrobiana de extratos brutos de plantas provenientes do Cerrado Brasileiro contra estirpes de espécies de referência do complexo B. burgdorferi s.l.. Foi avaliada a concentração inibitória mínima (MIC) de quatro extratos brutos (etanólicos e aquosos) das espécies Eugenia dysenterica e Pouteria ramiflora face a estirpes de Borrelia das espécies B. burgdorferi sensu stricto (s.s,), B. garinii, B. bavariensis e B. afzelii, usando o método de microdiluição em placa descrito na norma
M27-A2 do Clinical Laboratory Standards Institute (CLSI), com algumas
modificações.
Os extratos testados apresentaram um comportamento semelhante com as estirpes em estudo, sendo eficazes contra as mesmas. Quando comparados os extratos etanólicos e aquosos, os primeiros mostraram possuir maior eficácia, uma vez que, apresentaram valores de MIC de 312,5 a 2500 μg/mL enquanto os extratos aquosos apresentaram
valores entre 2500 a 10000 μg/mL. O extrato etanólico de Eugenia dysenterica mostrou possuir uma melhor eficácia contra todas as espécies utilizadas do complexo B. burgdorferi s.l..
Os compostos bioativos presentes nos extratos brutos estudados demonstraram possuir atividade antimicrobiana, pelo que os resultados obtidos, embora preliminares, são promissores para o futuro isolamento de novas moléculas bioativas que poderão ser usadas no tratamento da BL.
Lyme Borreliosis (LB) is a multissistemic and infectious disease caused by bacteria (spirochetes) belonging to Borrelia burgdorferi sensu lato (B. burgdorferi s.l.) complex, that are transmitted by vectors (ticks), mainly Ixodes ricinus species, in European continent. The disease has a worldwide distribution, being more prevalent in the United States of America and Europe. In Portugal is considered a notifiable disease since 1999. The disease can affect multiples organs and systems, depending on the infecting species, since each has a different tropism and can range from skin manifestations to neurological complications. Treatment is conducted using antimicrobials such as doxycycline, amoxicilin and ceftriaxone. However, novel compounds based on plant extracts have been investigated, as an alternative therapy in order to reduce the adverse effects which may result from long term use of these antimicrobials. Brazil is known to have a rich biodiversity, which derived bioactive compounds of its flora have been used in the treatment of a wide range of diseases. So, the aim of this study was to investigate the antimicrobial activity of plant crude extracts from the Brazilian Cerrado against strains of the reference species of B. burgdorferi s.l. complex. The Minimal Inhibitory Concentration (MIC) of four crude extracts (ethanolic and aqueous) belonging to the species Eugenia dysenterica and Pouteria ramiflora against strains of diverse Borrelia species, such as B. burgdorferi. sensu stricto (s.s,), B. garinii, B. bavariensis and B. afzelii, was evaluated using the microdilution method of the Clinical Laboratory Standards Institute (CLSI), with some modifications. The extracts tested showed a similar behavior with the studied strains under study, being effective against them. When comparing the ethanolic and aqueous extracts, the first showed to possess higher efficacy, once MIC values ranged from 312.5 to 2500 μg/mL, while the aqueous extracts exhibited values between 2500 to 10,000 μg/mL. From all the tested ethanolic extract of Eugenia dysenterica species revealed a better efficacy against all species of B. burgdorferi s.l. complex. The bioactive compounds present in crude extracts tested, showed to possess antimicrobial activity, consequently, the results obtained although preliminary are promising for the future isolation of new bioactive molecules which can be used in LB treatment.
Lyme Borreliosis (LB) is a multissistemic and infectious disease caused by bacteria (spirochetes) belonging to Borrelia burgdorferi sensu lato (B. burgdorferi s.l.) complex, that are transmitted by vectors (ticks), mainly Ixodes ricinus species, in European continent. The disease has a worldwide distribution, being more prevalent in the United States of America and Europe. In Portugal is considered a notifiable disease since 1999. The disease can affect multiples organs and systems, depending on the infecting species, since each has a different tropism and can range from skin manifestations to neurological complications. Treatment is conducted using antimicrobials such as doxycycline, amoxicilin and ceftriaxone. However, novel compounds based on plant extracts have been investigated, as an alternative therapy in order to reduce the adverse effects which may result from long term use of these antimicrobials. Brazil is known to have a rich biodiversity, which derived bioactive compounds of its flora have been used in the treatment of a wide range of diseases. So, the aim of this study was to investigate the antimicrobial activity of plant crude extracts from the Brazilian Cerrado against strains of the reference species of B. burgdorferi s.l. complex. The Minimal Inhibitory Concentration (MIC) of four crude extracts (ethanolic and aqueous) belonging to the species Eugenia dysenterica and Pouteria ramiflora against strains of diverse Borrelia species, such as B. burgdorferi. sensu stricto (s.s,), B. garinii, B. bavariensis and B. afzelii, was evaluated using the microdilution method of the Clinical Laboratory Standards Institute (CLSI), with some modifications. The extracts tested showed a similar behavior with the studied strains under study, being effective against them. When comparing the ethanolic and aqueous extracts, the first showed to possess higher efficacy, once MIC values ranged from 312.5 to 2500 μg/mL, while the aqueous extracts exhibited values between 2500 to 10,000 μg/mL. From all the tested ethanolic extract of Eugenia dysenterica species revealed a better efficacy against all species of B. burgdorferi s.l. complex. The bioactive compounds present in crude extracts tested, showed to possess antimicrobial activity, consequently, the results obtained although preliminary are promising for the future isolation of new bioactive molecules which can be used in LB treatment.
Descrição
Palavras-chave
Borreliose de Lyme Extratos MIC Compostos bioativos Biologia molecular Ciências biomédicas
Contexto Educativo
Citação
Editora
Instituto de Higiene e Medicina Tropical