Antimicrobial activity of amazonian medicinal plants

Amanda A Oliveira,Paulo Om Junior,Magda Ca Gonçalves,Vespasiano Yk Sousa,Elida Cg Mata,Luís Ib Kanzaki,Roberto M Bezerra,Jorge Fo Segovia

doi:10.1186/2193-1801-2-371

Abstract

ObjectivesThe aqueous extracts of currently utilized Amazonian medicinal plants were assayed in vitro searching for antimicrobial activity against human and animal pathogenic microorganisms.MethodsMedium resuspended lyophilized aqueous extracts of different organs of Amazonian medicinal plants were assayed by in vitro screening for antimicrobial activity. ATCC and standardized microorganisms obtained from Oswaldo Cruz Foundation/Brazil were individually and homogeneously grown in agar plate, and holes previously perforated in the gel were filled with diluted plant aqueous extracts. Inhibition halos were evaluated and controlled by the use of the fluoroquinolone ciprofloxacin.ResultsThe Amazonian medicinal plants, Hymenelobium petraeum showed inhibitory activity over Staphylococcus aureus, Enterococcus faecalis, Salmonella enterica serovar Typhi, Acinetobacter baumannii and Candida albicans, while Vatairea guianensis and Symphonia globulifera presented inhibitory activity exclusively for Staphylococcus aureus. Also, Ptychopetalum olacoides and Pentaclethra macroloba inhibited the growth of Klebsiella ozaenae and Acinetobacter baumannii.ConclusionThe aqueous botanic extracts that showed activity against microroganisms of ATTC and Osvaldo Cruz strains had at least 40% of antimicrobial activity when compared to halo inhibition produced by the commercial antibiotic ciprofloxacin utilized as a control. Of all plants extracts assayed, the Hymenelobium petraeum had the best performance, sometimes exhibiting higher activity than ciprofloxacin. It is not well-defined by the physicians the exact indication of the majority of medicinal plants in the Amazon area in Brazil. Natives utilize the plants according to their symptoms, based on the traditional knowledge transmitted orally from generation to generation, among Amerindians, Afrodescendents and ethnic mixed populations. A significant number of Amazonian medicinal plants are totally unknown related to their medicinal properties including mechanism of action and therapeutic effects, as very few information is reported in the scientific literature. A tiny amount of data is presented, as the preliminary antimicrobial properties of the medicinal plants here accessed, under the urgent necessity of new antibiotics in the market and in face of the increased resistance of infectious microorganisms to antimicrobials.

Highlights

Nowadays, an increasing number of infectious agents are becoming more resistant to commercial antimicrobial compounds (Hancock et al 2012)
Considering that 9 mm halo inhibition produced by the commercial antibiotic ciproflacin over Staphylococcus aureus represents 100% of antibacterial activity, the botanic aqueous extracts of Vatairea guianensis had 44.4% (4 mm) activity while Symphonia globulifera and Hymenelobium petraeum (3.66 mm) 40.6%
The botanic aqueous extract of Pentaclethra macrolaba did not show any activity over Staphylococcus aureus, but inhibited the growth of Klebsiella ozaenae and Acinetobacter baumannii, representing 49.5% (3.96 mm halo) and 52.4% (5.76 mm halo) respectively, of the ciprofloxacin halo produced (8 mm and 11 mm halo respectively)

Summary

Introduction

An increasing number of infectious agents are becoming more resistant to commercial antimicrobial compounds (Hancock et al 2012). It is a common sense that the extensive Amazonian biodiversity, scarcely explored the economic rationality, would yield uncouns opportunities to find plant species potentially secreting metabolites, exhibiting antimicrobial activity, among other medicinal properties (Vieira et al 2008; Basso et al 2005). The ethanolic extracts of Geissospermum argenteum, Uncaria guianensis, Brosimum acutifolium, Copaifera reticulate, Licania macrophylla, Ptycopetalum olacoides and Dalbergia subcymosa exhibited inhibitory activity against multiresistant and Staphylococcus aureus and Pseudomonas aeruginosa ATCC strains (Correia et al 2008). Ethanolic extracts of Copaifera reticulata, Tabebuia serratifolia, Brosimum rubescens and Carapa guianensis inhibited the colony formation of gram positive bacilli of Bacillus gender and Pseudomonas aeruginosa, microorganisms isolated from biocorroded metallic structures in a hydroelectric power unit, in the Amapa state (Correia et al 2010). Among the species of the Fabaceae, Caesalpiniaceae, Olacaceae, Chrysobalanaceae, Apocynaceae, Rubiaceae and Clusiaceae families, collected in the Amapa state, we detected antiretroviral, and lymphoproliferative activity, and cytotoxicity for lymphoma/leukemia derived cell lines (Mata 2011)

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