RESUMO
Several bradykinin potentiators were identified in the venom of Bothrops jararacussu by chromatographic techniques and biological assays. One of them which was isolated inhibited the angiotensin-converting enzyme in vitro and potentiated the bradykinin-induced lowering of the arterial pressure in the rat.
Assuntos
Bradicinina/farmacologia , Venenos de Crotalídeos/farmacologia , Músculo Liso/efeitos dos fármacos , Oligopeptídeos/farmacologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Captopril/farmacologia , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Venenos de Crotalídeos/química , Sinergismo Farmacológico , Feminino , Cobaias , Íleo , Masculino , Contração Muscular/efeitos dos fármacos , Oligopeptídeos/química , Oligopeptídeos/isolamento & purificação , Técnicas de Cultura de Órgãos , Ratos , SerpentesRESUMO
The venom of the Brazilian snake Bothrops jararacussu, was found to contain peptides capable of potentiating the smooth muscle contracting activity of bradykinin (BK). Chromatographic separation on Sephadex G-25 and Sephadex G-10 respectively, yielded an active peptide which at a concentration of 0.6 micrograms/ml doubled the effect of a single dose of BK on the isolated guinea-pig ileum. HPLC chromatography showed this material to contain one major and 4 minor components. The active peptide was 2-3 times more active than Captopril in the potentiation of the effects of BK on rat arterial blood pressure and on the isolated guinea pig ileum. It also showed marked capacity to inhibit angiotensin I-converting enzyme.
Assuntos
Venenos de Crotalídeos/farmacologia , Peptídeos/farmacologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Bradicinina/farmacologia , Venenos de Crotalídeos/química , Feminino , Liofilização , Cobaias , Íleo/efeitos dos fármacos , Técnicas In Vitro , Masculino , Peso Molecular , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Peptídeos/isolamento & purificação , RatosRESUMO
The 5-hydroxy-3,6,7,3',4'-pentamethoxyflavone (artemetin) from Cordia verbenacea DC (Boraginaceae) showed marked anti-inflammatory activity using various experimental models in rats. Artemetin significantly inhibited carrageenin-induced paw edema following oral doses from 30.4 to 153.9 mg.kg-1. The doses of 102.6 and 153.9 mg.kg-1 showed an inhibitory effect similar to that of 50.0 mg.kg-1 of calcium phenylbutazone. The ED50 value of artemetin in rats was estimated to be 67.07 mg.kg-1. Repeated administration of artemetin at doses of 67.07 mg.kg-1 for a 6-day period reduced granuloma formation with a response comparable to that of 20.0 mg.kg-1 of calcium phenylbutazone. This same dose of artemetin also reduced the vascular permeability to intracutaneous histamine. Sub-acute toxicological experiments indicated a very low toxicity.