Antimicrobial activity of plants used as medicinals on an indigenous reserve in Rio das Cobras, Parana, Brazil

Ethnopharmacological relevance: A considerable percentage of global biodiversity is located in Brazil, a country that also has rich cultural and ethnic diversity. In the community of Rio das Cobras, Parana, plants are still widely used in the health care not only by indigenous people but also by the non-indigenous population that inhabits the region. The investigation of the efficacy and safety of these plants in the treatment of infectious diseases provides insights for future studies of these species allowing the appropriated use by the indigenous people, since few or none study has been conducted so far. Aim of the study: Evaluate the antimicrobial activity and cytotoxicity of some plants used as medicinal on an indigenous reserve in Rio das Cobras, Parana, Brazil. Materials and methods: The aqueous extracts were obtained by decoction and the 50% and 70% hydroalcoholic extracts by turbo extraction. The extracts were tested against strains of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Candida albicans, Candida parapsilosis, Candida tropicalis, Leishmania amazonensis, Poliovirus and HSV-1. Cytotoxicity assay using VERO cells were also performed. Results: None of the extracts had a selectivity index (SI) > 1 for any of the tested bacteria. Only Campomanesia eugenioides and Schinus terebinthifolius had an SI > 1.0 for all of the tested Candida species. The best anti-Leishmania activity was obtained with Zanthoxylum rhoifolium and Schinus terebinthifolius. Extracts of Cordia americana were the most effective against herpes simplex virus type 1. Zanthoxylum rhoifolium was the most effective against Poliovirus, and Ocimum gratissimum was effective against both Poliovirus and Herpes Simplex virus. Among the plants investigated in the present study, Zanthoxylum rhoifolium had the fewest cytotoxic effect. Conclusions: The plants investigated in the present study exhibited potential for future pharmacological uses, but additional studies, especially with regard to in vivo toxicity, must be conducted. The results of this preliminary survey are important for the Rio das Cobras Reserve community for the safe and effective use of plants in the treatment of some infectious diseases. (C) 2012 Elsevier Ireland Ltd. All rights reserved.