Résumé
A atividade larvicida de quatro saponinas monodesmosídicas (1-4) isoladas de Pentaclethra macroloba e de uma saponina bidesmosídica (5) isolada de Cordia piauhiensis foi avaliada sobre larvas de estágio 3 de Aedes aegypti. As larvas foram expostas a várias concentrações (500, 250, 100, 50, 25 e 12,5 mg/mL) das saponinas por um período de 24 h. Os resultados indicam que somente as saponinas 1-3 mostraram alta atividade larvicida, com CL50 variando de 18,6 a 27,9 mg/mL. Estes resultados ressaltam as potencialidades destas saponinas como possíveis agentes larvicidas naturais.
The larvicidal activity of the four monodesmoside saponins (1-4) isolated from Pentaclethra macroloba and one bidesmoside saponin (5) from Cordia piauhiensis was evaluated on 3rd instar larvae of Aedes aegypti. The larvae were exposed to serial concentrations (500, 250, 100, 50, 25 and 12.5 mg/mL) saponins for a period of 24 h. The results indicate that, only the saponins 1-3 showed high larvicidal activity, with LC50 ranging of 18,6-27,9 mg/mL. These results suggest that these can be used as natural larvicidal agents.
Résumé
No período de janeiro à dezembro de 2003 foram enviados ao Laboratório Central do estado do Ceará ( LACEN-Ce), 1.028 espécimes clínicos (urina), coletados de 112 pacientes com suspeita de tuberculose urogenital, onde 79 (7,7) destes espécimes apresentaram baciloscopia e cultura positiva para o complexo Mycobacterium tuberculosis. Dos 112 pacientes apenas 40 (35,7)...
Sujets)
Mâle , Femelle , Humains , Tuberculose urogénitale , Techniques de laboratoire clinique , Mycobacterium tuberculosisRésumé
Auxemma oncocalyx Taub. belongs to the Boraginaceae family and is native to the Brazilian northeast where it is known as "pau-branco". We investigated the ability of the water soluble fraction isolated from the heartwood of A. oncocalyx to inhibit sea urchin egg development. This fraction contains about 80 percent oncocalyxone A (quinone fraction), a compound known to possess strong cytotoxic and antitumor activities. In fact, the quinone fraction inhibited cleavage in a dose-dependent manner [IC50 of 18.4 (12.4-27.2) æg/ml, N = 6], and destroyed the embryos in the blastula stage [IC50 of 16.2 (13.7-19.2) æg/ml, N = 6]. We suggest that this activity is due to the presence of oncocalyxone A. In fact, these quinones present in A. oncocalyx extract have strong toxicity related to their antimitotic activity