Acute and sub-acute oral toxicity studies of standardized extract of Nasturtium officinale in Wistar rats.

Nasturtium officinale (watercress) is a perennial dicotyledonous plant, rich in vitamins, minerals and chemical compounds. The leaves of this plant, which contain glucosinolate, are used for its diuretic and hypoglycemic effects. The purpose of the study was to investigate the safety of the standardized extract of Nasturtium officinale (SENO) with phenylethyl glucosinolate 5.0 mg/ml-1, using acute and sub-acute oral dosage in Wistar rats. High-Performance Liquid Chromatography (HPLC) analyzed the chemical composition, from aerial parts of watercress. In the acute toxicity study, dose estimated was LD50 in the range of 2000-5000 mg/kg, signs of mortality and toxicity on female rats were observed for 14 days, after single doses of 2000 and 5000 mg/kg. In the sub-acute study, female and male rats, age 10 weeks, were supplemented at doses of 250, 500 and 1000 mg/kg for 28 days. On the 29th day, rats were fasted, anesthetized, euthanized, then their blood used for hematological and biochemical evaluation. No significant changes in general behavior were reported regarding the acute study, while the sub-acute study demonstrated no toxicity of the hematopoietic and biochemical systems. The results showed that SENO at dosage up to 5000 mg/kg in acute study was safe, and NOAEL (no-observed-adverse-effect levels) in the sub-acute, was up to 1000 mg/kg.

Atividade antimicrobiana do extrato bruto etanólico de raízes e partes aéreas de Ottonia martiana Miq. (Piperaceae) / Antimicrobial activity of crude ethanolic extracts of Ottonia martiana Miq. (Piperaceae) roots and aerial parts

Ottonia martiana Miq., Piperaceae, conhecida na medicina popular brasileira como "anestésia", é um arbusto característico da Floresta Atlântica. Devido à ação anestésica sobre a mucosa oral, raízes e partes aéreas são popularmente utilizadas em dores de dente, na forma de alcoolaturas (bochechos) ou pela mastigação de fragmentos de partes da planta. Como os microrganismos estão adquirindo resistência aos antibióticos tradicionais, a procura por novos agentes antimicrobianos, a partir de plantas, vem sendo intensificada. Nesta perspectiva, avaliou-se o efeito antimicrobiano do extrato bruto etanólico dos órgãos totais desta espécie (EBEtOH) frente às bactérias Enterococcus faecium (ATCC 6569), Enterobacter aerogenes (ATCC 13048) e Pseudomonas aeruginosa (ATCC 15442), utilizando-se os métodos de difusão em ágar e bioautografia. Os resultados obtidos por difusão em ágar mostraram que o EBEtOH de O. martiana apresenta potencial antibacteriano contra E. faecium, evidenciado pelo aparecimento de zonas de inibição de crescimento no respectivo bioautograma e não demonstraram ação antimicrobiana contra as outras cepas testadas.

Ottonia martiana Miq., Piperaceae, known in Brazilian folk medicine as "anestésia", is an herbaceous shrub found in Atlantic Tropical Forest. Due to its anesthetic action on the mucous membranes of the mouth, roots and aerial parts are commonly used to relief toothache, usually as alcoholic macerates (mouth washing) or by chewing parts of the plant. As most microorganisms are acquiring resistance to traditional antibiotics, the search for new antimicrobials agents, specially from plants, is being intensified. Based on this, the activity of the crude ethanolic extract from roots and aerial parts (EBEtOH) of O. martiana against Enterococcus faecium (ATCC 6569), Enterobacter aerogenes (ATCC 13048) and Pseudomonas aeruginosa (ATCC 15442) was evaluated using the agar difusion and bioautographic methods. Results from the agar diffusion assay showed that O. martiana EBEtOH has a potencial effect against E. faecium, which was corroborated by the presence of inhibition zones in the bioautographic test, whereas no inhibitory action against the other assayed bacteria was observed.