RESUMO
Hypotensive action mechanism of a cation exchange resin adsorbate (IR-120A) separated from a Paraguayan Natural Medicine, Nangapiry, was investigated. Blood pressures of normal and pithed rats and contractions of isolated thoracic aorta and atria of mice were measured. The blood pressure on normal rats was reduced by an intravenous injection of IR-120A (5 mg/kg). The hypotensive effect on the pithed rat appeared more lasting than that on normal rats by IR-120A. The IR-120A (100 microg-3 mg/ml) concentration-dependently depressed prostaglandin (PG) F2alpha (10 microM)- or KCl (40 mM)-induced aortic contractions and electrically-evoked contraction of left atria, and at a lesser extent spontaneous beating rate of right atria. The 50% inhibitory concentrations (IC50) for the PGF2alpha- and KCl-induced aortic contractions were 713 and 828 microg/ml, respectively, and the IC50 values for the muscle contraction and the beating rate were 1.04 and >3 mg/ml, respectively. These results suggest that the hypotensive action of IR-120A are peripherally elicited by the dilatation of artery and the depression of heart contraction, but not the reduction of heart rate.
Assuntos
Pressão Sanguínea/efeitos dos fármacos , Medicina Tradicional , Contração Muscular/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , Contração Miocárdica/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantas Medicinais , Animais , Aorta Torácica/fisiologia , Cromatografia por Troca Iônica , Átrios do Coração , Técnicas In Vitro , Resinas de Troca Iônica , Masculino , Camundongos , Camundongos Endogâmicos , Músculo Liso Vascular/efeitos dos fármacos , Paraguai , Folhas de Planta , Ratos , Ratos Sprague-DawleyRESUMO
The water-soluble extract from a Paraguayan natural medicine, Nangapiry, the leaves of Eugenia uniflora L. (Myrtaceae), which has been used as an antidiabetic agent, was found to show inhibitory activities on the increase of plasma glucose level in the sucrose tolerance test (STT) conducted with mice. The portion adsorbed on a cation exchange resin was also found to inhibit a-glucosidases. From the active portion, two new active compounds named uniflorines A ( 1 ) and B ( 2 ) and known (+)-(3a, 4a, 5ß)-1-methylpiperidine-3, 4, 5-triol ( 3 ) were isolated. The structures of uniflorines A and B were determined as (-)-(1S, 2R, 6S, 7R, 8R, 8aR)-1,2,6,7,8-pentahydroxyindolizidine and (+)-(1S, 2R, 5R, 7R, 8S, 8aS)-1,2,5,7,8-pentahydroxyindolizidine by spectral means, respectively.
RESUMO
The anti-inflammatory active fraction of the Paraguayan crude drug, "Alhucema," Lavandula latifolia Vill. afforded four compounds: coumarin (1), 7-methoxycoumarin (2), trans-phytol (3) and caryophyllene oxide (4). 1 showed a weakly inhibitory effect on carrageenin-induced paw edema in rats on topical application and 4 showed an inhibitory effect on histamine-induced contraction in guinea pig ileum.
Assuntos
Anti-Inflamatórios não Esteroides/análise , Cumarínicos/análise , Fitol/análise , Plantas Medicinais/análise , Sesquiterpenos/análise , Animais , Bioensaio , Cobaias , Técnicas In Vitro , Paraguai , Sesquiterpenos Policíclicos , RatosRESUMO
Aldose reductase (AR) inhibitory activity-directed fractionation of the 70% ethanolic extract of Para-parai mí, Phyllanthus niruri, has led to the isolation of three active components, ellagic acid (1), brevifolin carboxylic acid (4) and ethyl brevifolin carboxylate (5). Among them, 1 showed the highest inhibitory activity, being about 6 times more potent than quercitrin, which is a known natural inhibitor of AR.