RESUMEN
Ethanol extract of Maytenus rigida stem bark and its fractions were assessed for antinociceptive activity in tail-flick test in rats. The activity was located in the chloroform, ethyl acetate and aq.methanol fractions. Phytochemical screening revealed that catechin was the only common class of compounds present on the ethanol extract as well as on the active fractions. 4'-Methylepigallocatechin, isolated from the ethyl acetate and aq.methanol fractions, showed antinociceptive effect in the tail-flick test (75 mg/kg; p.o.), which was reversed by the opiate antagonist naloxone (3 mg/kg; i.p.).
Asunto(s)
Analgésicos/farmacología , Maytenus , Dolor/prevención & control , Fitoterapia , Extractos Vegetales/farmacología , Analgésicos/administración & dosificación , Analgésicos/uso terapéutico , Animales , Relación Dosis-Respuesta a Droga , Calor , Masculino , Dimensión del Dolor/efectos de los fármacos , Corteza de la Planta , Extractos Vegetales/administración & dosificación , Extractos Vegetales/uso terapéutico , Tallos de la Planta , Ratas , Ratas WistarRESUMEN
Caesalpinia ferrea is a plant very used in the folk medicine for treatment of several diseases, such as diabetes. This study investigated the cardiovascular effects of the aqueous extract from stem bark of C. ferrea (AECF). In non-anesthetized rats, AECF (10, 20, 40, 60 and 80 mg/kg; i.v.) induced hypotension (-9+/-1;-12+/-1;-14+/-1; -20+/-3 and -51+/-6%; respectively) and tachycardia (6+/-1; 8+/-1; 12+/-2; 14+/-2 and 26+/-3%; respectively). Hypotension was not affected after atropine or L-NAME. Furthermore, AECF (40 mg/kg) induced atrioventricular block and extrasystoles, which was not affected after atropine. In intact rings of the rat mesenteric artery, AECF (0.001-30 mg/ml, n=6) induced relaxations of phenylephrine tonus (Emax=110+/-4%), which was not changed after the removal of endothelium (Emax=113+/-9%). In rings without endothelium pre-contracted with KCl 80 mM, phenylephrine plus KCl 20 mM or phenylephrine plus glibenclamide, the curve to AECF was significantly attenuated (Emax=24+/-4%, 70+/-5% and 62+/-7%, respectively, n=6), but was not affected in the presence of tetraethylammonium or 4-aminopyridine (Emax=125+/-15% and 114+/-7%, respectively, n=6). These results demonstrate that AECF induces hypotension associated to tachycardia; however, in dose of 40 mg/kg, AECF induces transient bradyarrhythmias. Furthermore, AECF induces vasodilatation in rat mesenteric artery which appears to be mediated by ATP-sensitive K+ channel openings.
Asunto(s)
Adenosina Trifosfato/farmacología , Presión Sanguínea/efectos de los fármacos , Caesalpinia , Frecuencia Cardíaca/efectos de los fármacos , Extractos Vegetales/farmacología , Canales de Potasio/efectos de los fármacos , Animales , Atropina/farmacología , Electrocardiografía/efectos de los fármacos , Técnicas In Vitro , Masculino , Arteria Mesentérica Superior/efectos de los fármacos , Arteria Mesentérica Superior/fisiología , NG-Nitroarginina Metil Éster/farmacología , Canales de Potasio/fisiología , RatasRESUMEN
The aqueous extract of Hyptis suaveolens leaves was studied for their antinociceptive property in chemical and thermal models of nociception in mice. Oral administration of the aqueous extract (100, 200, and 400 mg/kg) dose-dependently reduced the number of writhings induced by acetic acid, decreased the licking activity of the early phase in formalin test and increased the reaction time in hot-plate test. The antinociceptive effect was significantly antagonized by naloxone (3 mg/kg; i.p.). Preliminary acute toxicity study showed that no animal death with doses up to 5 g/kg (p.o.).
Asunto(s)
Analgésicos/farmacología , Hyptis , Dolor/prevención & control , Fitoterapia , Extractos Vegetales/farmacología , Ácido Acético , Administración Oral , Analgésicos/administración & dosificación , Analgésicos/uso terapéutico , Animales , Relación Dosis-Respuesta a Droga , Femenino , Calor , Masculino , Ratones , Dolor/inducido químicamente , Extractos Vegetales/administración & dosificación , Extractos Vegetales/uso terapéutico , Hojas de la PlantaRESUMEN
The essential oil of the Hyptis fruticosa leaves was analyzed by GC/MS and evaluated for antinociceptive property as well as acute toxicity in mice. The essential oil, at doses of 100, 200, and 400 mg/kg (s.c.), produced significant inhibition of acetic acid-induced writhing, but did not manifest a significant effect in hot-plate test. There was no acute toxicity at doses up to 5 g/kg. Bicyclogermacrene, 1,8-cineole, alpha-pinene, and beta-caryophyllene were the major compounds detected in the essential oil.