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

Preliminary Assessment of the Chemical Stability of Dried Extracts from Guazuma ulmifolia Lam. (Sterculiaceae).

We report the results of a preliminary estimation of the stability of the dried extract from bark of Guazuma ulmifolia Lam. ("Mutamba"), with and without added colloidal silicon dioxide (CSD). The physical and chemical properties and the compatibility of CSD in the extract were evaluated for 21 days of storage under stress conditions of temperature (45 ± 2°C) and humidity (75 ± 5%). Thermogravimetry (TG) was supplemented using selective high-performance liquid chromatography (HPLC) for determination of stability of the characteristic constituents (chemical markers), namely, procyanidin B2 (PB2) and epicatechin (EP). The results showed that PB2 is an appropriate compound to be used as a chemical marker in the quality control of dried extracts of G. ulmifolia. The stress study showed that there was no significant difference between the two formulations. However, considering the TG data and the high temperatures involved, the results suggest that CSD increases the stability of the dried extract of G. ulmifolia.

Influence of extracts of Stryphnodendron polyphyllum Mart. and Stryphnodendron obovatum Benth. on the cicatrisation of cutaneous wounds in rats.

Stem bark of the two species Stryphnodendron polyphyllum Mart. and Stryphnodendron obovatum Benth., Leguminosae, was investigated for wound healing, antibacterial and antioxidant activity. These plants contain 12 and 19% tannins in their stem bark, respectively, and are widely used in traditional medicine in Brazil. The total content of phenolics of the crude extract (CE) of Stryphnodendron obovatum was 76.95 +/- 2.98% (CV = 3.87%) and of the ethyl-acetate fraction (EAF) was 89.13 +/- 0.34% (CV = 0.38%); whereas in Stryphnodendron polyphyllum the CE phenolics content was 51.62+/-1.53% (CV = 2.96%) and the EAF phenolics content was 59.00 +/- 1.91% (CV = 3.24%). The tannin content of CE from Stryphnodendron obovatum [36.58 +/- 0.35% (CV = 0.98%)] was about 11% higher than in CE from Stryphnodendron polyphyllum [25.43 +/- 0.96% (CV = 3.77%)]. The difference between the species was even greater in the EAF: in Stryphnodendron obovatum the EAF phenolics content was 55.01 +/- 0.36% (CV = 0.65%), whereas in Stryphnodendron polyphyllum the content was 36.16 +/- 0.42% (CV = 1.16%). The healing effect of ointments containing 2.5% crude lyophilised extract (PCE) and 2.5% ethyl-acetate lyophilised fraction (PEA) of the stem bark of Stryphnodendron polyphyllum and Stryphnodendron obovatum was studied in cutaneous wounds of Wistar rats after 4, 7 and 10 days of treatment. Epithelial cell proliferation in the area of re-epithelialisation of the wounds was evaluated by counting the metaphases blocked by vincristine sulfate. With PCE an increase in epidermal growth was observed after 4 and 7 days of treatment with Stryphnodendron polyphyllum, and after 7 and 10 days of treatment with Stryphnodendron obovatum. Wounds treated with PEA of Stryphnodendron obovatum showed increased epidermal growth only 4 days after the treatment; for Stryphnodendron polyphyllum, epidermal growth was observed after 4 and 7 days of treatment. Both the CE and the EAF fractions of Stryphnodendron polyphyllum and Stryphnodendron obovatum showed antibacterial activity against Staphylococcus aureus with MIC values of 125 and 250 microg/ml, respectively. Gram-negative bacteria tested were not inhibited by extracts and fractions at concentrations > 1000 microg/ml. The antioxidant activity through reduction of the DPPH radical in TLC, confirmed the anti-radical properties of these extracts in both species. CE and EAF of both species showed a radical scavenging activity (RSA) and protected DPPH from discolouration, already at 0.032 microg/ml. The extract from Stryphnodendron polyphyllum were more effective than those Stryphnodendron obovatum, although the former had a lower tannin content.