RESUMEN
The intra-venous (i.v.) hypotensive action of the final aqueous fraction of Pimenta dioica was studied in Spontaneously Hypertensive Rats (SHR). The rats were anaesthetized (sodium pentobarbital 50 mg/kg), the trachea, right carotid artery and jugular vein were cannulated for adequate ventilation, direct blood pressure measurement and intra-venous administration of extracts, solutions and drugs. The arterial line was connected to a pressure transducer (Viggo-Spectramed model P23 XL) and a polygraph (Grass model 7H) and monitored continuously during the first five minutes after plant extract administration and then at 5 and 15 minute intervals for one hour. Responses were taken as the maximum pressure changes observed during this period. Increasing doses of the final aqueous fraction were given i.v. to groups of six SHR each. It produced a dose dependent decrease in blood pressure and the ED50 was 45 mg/kg. To discard that the hypotensive effect of the extracts was due to its ionic composition, a solution containing KCl, NaCl, CaCl2 and MgCl2 equivalent to the ion contents present in a dose of 50 mg/kg of total aqueous extract was injected to Sprague-Dawley rats (SDN) using the same method as described above. It did not produce significant changes in blood pressure. Pharmacological antagonistic studies were done injecting either autonomic ganglion, alpha adrenoceptor, beta adrenoceptor and cholinergic receptor blockers prior to extract administration in SHR rats. Atropine, propranolol and phentolamine did not affect the hypotensive effect of the final aqueous fraction. With hexamethonium (autonomic ganglion blocker) the hypotensive response was diminished in a significant way (p < 0.05). The hypotensive action of the final aqueous extract was not mediated through cholinergic, alpha or beta adrenergic receptors. The extract may posses vasorelaxing activity which could not be evident after autonomic ganglion blockade due to extreme vasodilation present prior to extract administration. Future studies should address the question of a possible direct vasodilating effect of the extracts.
Asunto(s)
Antihipertensivos/farmacología , Presión Sanguínea/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Extractos Vegetales/farmacología , Animales , Antihipertensivos/uso terapéutico , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Hipertensión/tratamiento farmacológico , Masculino , Extractos Vegetales/uso terapéutico , Ratas , Ratas Sprague-DawleyRESUMEN
The composition of the essential oil isolated by steam distillation from aerial parts of the Costa Rican herb Lepechinia schiedeana (Schlecht) Vatke (Lamiaceae) collected in El Empalme, Costa Rica, was determined by capillary gas chromatography (GC) and coupled gas chromatography-mass spectrometry (GC-MS) analyses. Fifty-one components were identified corresponding ca. 93% of the oil. The major components were beta-pinene (26.6%), cis-pinocamphone (25.1%), delta-3-carene (6.1%), trans-pinocamphone (4.0%), camphor (3.8%) and beta-caryophyllene (3.7%).
Asunto(s)
Lamiaceae/química , Aceites Volátiles/química , Aceites de Plantas/química , Cromatografía de Gases , Costa Rica , Espectrometría de MasasRESUMEN
The constituents of the volatile oil of Cunila polyantha from Dota, Costa Rica, were investigated using coupled gas chromatography-mass spectrometry (GC-MS) analyses. Menthone (63%), pulegone (14%), beta-caryophyllene (4.5%) and 3-octanyl acetate (3%) were found to be the major constituents of the volatile oil.
Asunto(s)
Lamiaceae/química , Aceites Volátiles/química , Aceites de Plantas/química , Cromatografía de Gases , Costa Rica , Espectrometría de MasasRESUMEN
The composition of the essential oils of the leaves and fruits of Drimys granadensis L. f. (Winteraceae) obtained by hydrodistillation were investigated by GC-MS. The main constituents of the leaves oil were the monoterpenoids 4-terpineol (21.9%), sabinene (16.6%), gamma-terpinene (8.3%) and alpha-terpinene (5.5%), together with the sesquiterpene germacrene-D (10.2%). The main constituents of the unripe-fruit oil were the sesquiterpenoids germacrene-D (23.4%) and drimenol (10.0%).
Asunto(s)
Aceites Volátiles/análisis , Plantas/química , Hojas de la Planta/químicaRESUMEN
The composition of the essential oils of the leaves and spikes of Piper bisasperatum Trel. (Piperaceae) obtained by hydrodistillation were investigated by GC-MS. The main constituents of the leaves oil were the sesquiterpenes germacrene D (30.7%), beta-caryophyllene (9.5%) and gamma-elemene (5.9%), together with the monoterpene beta-pinene (5.5%). The main constituents of the spikes (flowers and fruits) were the monoterpenes beta-pinene (17.5%), alpha-pinene (14.0%) and the sesquiterpenes germacrene D (19.5%), beta-caryophyllene (7.9%) and ylangene (7.6%). The C6-C1 compounds benzyl benzoate (0.3%) and benzaldehyde (< 0.1%) were identified for the first time in the genus Piper.
Asunto(s)
Frutas/química , Aceites Volátiles/análisis , Hojas de la Planta/química , Costa Rica , Cromatografía de Gases y Espectrometría de Masas/métodosRESUMEN
The intraperitoneal administration of different extracts of Pimenta dioica (L.) Merrill (Myrtaceae) to conscious normotensive and hypertensive rats caused a depression of the central nervous system (CNS). The intensity of this depression depends on the dose. Analgesic and hypothermic effects were also observed. The total aqueous extract was more effective than the ethanolic extract and the final aqueous fraction was the most effective. The peritoneal irritation caused by the extract explains only partially the depressive effect over the CNS. When the final aqueous fraction was given orally to SDN and SHR rats during 14 days there was no observed change on the sistolic blood pressure, heart rate and weight of the animals.