Estudo toxicológico agudo do extrato etanólico de partes aéreas de Jatropha gossypiifolia L. em ratos / Acute toxicological studies of the ethanol extract of the aerial parts of Jatropha gossypiifolia L. in rats

Este trabalho teve como objetivo a avaliação da toxicidade aguda do extrato etanólico (EE) de partes aéreas de Jatropha gossypiifolia L., espécie vegetal muito usada na medicina popular, apesar de ser catalogada como planta tóxica. Ratos Wistar foram tratados por via oral com doses únicas do extrato (1,2 g/kg; 1,8 g/kg; 2,7 g/kg; 4,0 g/kg e 5,0 g/kg) e observados por 14 dias. Os principais sinais de toxicidade encontrados, em alguns animais, foram: ptose palpebral, perda de peso e paralisia do trem posterior. Outras alterações significativas ocorreram apenas em machos tratados com a dose de 5 g/kg: aumento dos níveis sangüíneos de creatinina, AST, sódio e potássio; diminuição dos níveis de uréia e albumina; leucopenia, além de discretas alterações na coloração e consistência de vísceras. A dose letal mediana (DL50) foi superior a 4,0 g/kg para machos e maior do que 5,0 g/kg para fêmeas. Estes resultados indicam uma toxicidade aguda oral relativamente baixa; contudo, ressaltam a necessidade da realização de estudos toxicológicos de longa duração com o EE de J. gossypiifolia L.

The aim of this work was the assessment of acute oral toxicity of the ethanol extract (EE) of the aerial parts of Jatropha gossypiifolia L. This plant is used in folk medicine despite its classification as a toxic plant. Wistar rats were treated per oralis with single doses of EE [1.2 g/kg; 1.8 g/kg; 2.7 g/kg; 4.0 g/kg and 5.0 g/kg (w.b.)] and observed for 14 days. The most important signs of toxicity were: ptosis; reduction of body weight and hindlimb paralysis. Other sgnificant alterations occurred only in males treated with 5.0 g/kg (w.b.): increase of creatinine, AST, sodium and potassium seric levels; reduction of urea and albumin; leukopenia and small alterations in color and consistence of viscera. The LD50 value was higher than 4.0 g/kg (w.b.) for males and higher than 5.0 g/kg (w.b) for females. These results indicate a low oral acute toxicity, in relative terms, however it shows the importance of long-term toxicological studies of the EE from J. gossypiifolia.

In vitro antimicrobial activity of an extract from anacardium occidentale Linn. on Streptococcus mitis, Streptococcus mutans and Streptococcus sanguis

The antimicrobial activity of an extract from stems of the cashew tree, Anacardium occidentale Linn, was evaluated on three cultures of bacteria, Streptococcus mitis, Streptococcus mutans, Streptococcus sanguis, found in dental plaque. The antimicrobial activity was carried out on solid media plates by a diffusion method for the screening and determination of Minimum Inhibitory Concentration (MIC) and Concentration of Minimum Inhibitory Adherence (CIMA). Chlorexidine gluconate (0.12%) was used as a positive control. The results showed effective inhibitory action of the extract when compared with Chlorexidine gluconate. Chlorexidine gluconate (0.12%) and the extract showed inhibitory action. Inhibition halos (MIC) were observed at a concentration of 12.5muL for S. mutans and 6.25 mg/L for S. mitis and S. sanguis. The results suggest that the extract from Anacardium occidentale Linn was also effective for CIMA (adherence) at concentrations of 0.3lmg/L for L for S. mutans and S. mitis and 0.15 mg/L for S. sanguis. the extract from the cashew tree systems showed a potential inhibitory action on the synthesis of glucan measured as the adherence to glass in sub inhibitory conditions. The results suggest that the cashew trees may have some therapeutic uses in dentistry and could be used as an oral antibacterial agent