Résumé
Bredemeyera floribunda roots are popularly used to treat snakebites in the semiarid region of Northeast Brazil, and previous studies indicate the anti-ophidian actions of triterpenoid saponins found in its roots. To assess B. floribunda root extract (BFRE) activity against the effects of Bothrops jararacussu venom (BjuV), antiphospholipasic, antiproteolytic, antihemorrhagic, antinecrotic, and anti-edematogenic activities were investigated in mice. Phytochemical analysis revealed the presence of saponins, flavonoids, and sugars, with rutin and saccharose being the major constituents of BFRE. Acute toxicity was determined and BFRE was nontoxic to mice. Phospholipase A2 and proteolytic activities induced by BjuV were inhibited in vitro by BFRE at all concentrations tested herein. BFRE (150 mg/kg) inhibited paw edema induced by BjuV (50 µg/animal), reducing total edema calculated by area under the curve, but carrageenan-induced paw edema was unchanged. Hemorrhagic and necrotizing actions of BjuV (50 µg/animal) were considerably decreased by BFRE treatment. Thus, BFRE blocked the toxic actions of B. jararacussu venom despite having no anti-inflammatory activity, which points to a direct inhibition of venom's toxins, as demonstrated in the in vitro assays. The larger amounts of rutin found in BFRE may play a role in this inhibition, since 3′,4′-OH flavonoids are known inhibitors of phospholipases A2.
Sujets)
Animaux , Mâle , Rats , Sérums antivenimeux/pharmacologie , Extraits de plantes/pharmacologie , Racines de plante/composition chimique , Venins de crotalidé/antagonistes et inhibiteurs , Oedème/traitement médicamenteux , Hémorragie/étiologie , Sérums antivenimeux/isolement et purification , Bothrops , Venins de crotalidé/toxicité , Polygalaceae/composition chimique , Modèles animaux de maladie humaine , Relation dose-effet des médicaments , Oedème/étiologie , Hémorragie/traitement médicamenteuxRésumé
Os autores estudam o padräo de normalidade para a audiometria do tronco cerebral e sua variaçäo em relaçäo à faixa etária. Foram selecionados 40 indivíduos de 9 a 59 anos de idade sem história pregressa de patologia otológica e com exame físico e audiometria tonal normal. Além do estudo médio das latências, conclui-se que o limiar ao B.E.R.A. aumenta com a idade em todas as curvas, apesar da audiometria tonal normal, e que as curvas I, III e V säo as mais consistentes e com valor clínico, e que a amplitude tem pouco valor prático