RESUMO
The aim of the study is to assess the hypotensive properties of the hydro-ethanolic crude root extract (CRE), the n-butanol fraction (F(BtOH)) and nuatigenin-3-O-ß-chacotriose, from Solanum sisymbriifolium Lam., in adrenal regeneration hypertension+deoxycorticosterone acetate (ARH+DOCA) rats, following a chronic administration. The roots of S. sisymbriifolium Lam. (Solanaceae) were extracted by reflux with ethanol-water 7:3 and the active extract was fractionated by bioassay-guided liquid-liquid separation. Nuatigenin-3-O-ß-chacotriose (B(3-1)) was identified as the main hypotensive compound from the crude drug by spectroscopic methods. Immature Wistar rats of both sexes were submitted to both surgery and deoxycorticosterone acetate treatment to obtain adrenal regeneration hypertensive rats (ARH+DOCA). Different groups of experimentally induced hypertensive rats were randomly allotted and received during 16 weeks a daily oral administration of 1% saline solution (0.1 mL/100g body weigh), 100.0 mg/kg of CRE, 10.0, 30.0 and 50.0 mg/kg of F(BtOH), and 1.0 mg/kg of B(3-1), respectively. In addition, two groups of ARH+DOCA rats were randomly assigned to receive either B(3-1) (1.0 mg/kg/day) or 1% of saline solution (0.1 mL/100g body weight/day) for 7 weeks and then a cross over procedure was performed in order to complete the 16th-week treatment. After 16 weeks of oral administration of crude root extract (CRE), butanolic fraction (F(BtOH)) and nuatigenin-3-O-ß-chacotriose (B(3-1)) a significant reduction of blood pressure value was induced in hypertensive animals (ARH+DOCA) in comparison to the control group receiving 1% saline solution, at the end of experiment. Administration of B(3-1) (1.0 mg/kg/day p.o.) to ARH+DOCA rats provoked a significant reduction of blood pressure, observed gradually from 5th week (p<0.05) to the end of the 16th week period of treatment (p<0.01). Moreover, in a cross over design it was observed that the reduction of blood pressure to normotensive condition is associated to B(3-1). The latest demonstrated that the blood pressure-lowering effect, in clearly hypertensive animals, is reversible and depend upon administration of nuatigenin-3-O-ß-chacotriose (B(3-1)). Our results demonstrated that daily oral administration of CRE, F(BtOH) and nuatigenin-3-O-ß-chacotriose from S. sisymbriifolium for a 16-week period exhibits an antihypertensive effect in experimentally hypertensive (ARH+DOCA) rats.
Assuntos
Anti-Hipertensivos/farmacologia , Hipertensão/tratamento farmacológico , Saponinas/farmacologia , Solanum/química , Triterpenos/farmacologia , Tropanos/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Esquema de Medicação , Hipertensão/fisiopatologia , Camundongos , Paraguai , Fitoterapia , Extratos Vegetais/farmacologia , Raízes de Plantas/química , RatosRESUMO
The aim of the present work is to evaluate the putative antidepressant-like effects of a hydro-ethanolic extract (CEAp) and their fractions from the aerial parts of Aloysia polystachya (Griseb.) Moldenke (Verbenaceae) on the performance of male mice in the forced swimming test (FST). A single dose (100.0mg/kgp.o.) of CEAp, in male mice provoked a significant reduction of the immobility time (p<0.01). Such effect was also observed with short-term treatment (7 days) with single doses of 1.0 (p<0.01), 10.0 (p<0.05) and 100.0 (p<0.05)mg/kg/day of CEAp. Additionally, in a different set of experiments, repeated administration in a 24-h period (24, 18 and 1h before swimming test) with doses of 1.0 (p<0.05) and 10.0 (p<0.05)mg/kg p.o., of CEAp and 10.0mg/kgp.o., (p<0.05) of ethyl acetate fraction, provoked significant reduction of the immobility time of male mice in the FST. Moreover, it was noted important differences in the onset of the antidepressant-like effect in the FST, depending on the modality of treatment with CEAp (acute, short-term or repeated). Both, efficacy and potency were higher when repeated administration of CEAp was used, and surprisingly the dose of 10mg/kg (24, 18 and 1h before swimming test) was more effective than imipramine. In the same way, the short term administration (7 days) improved significantly efficacy and potency of the CEAp in comparison to a single dose treatment. The ethyl acetate fraction submitted to TLC demonstrated that main and minor components are phenolics and terpenes, respectively. In addition, this fraction gives a negative Shinoda's test for flavonoids. These results indicate an antidepressant-like profile of action for the hydro-ethanolic extract and the component(s) of the ethyl acetate fraction obtained from A. polystachya, which deserve further investigation.
Assuntos
Antidepressivos/análise , Resposta de Imobilidade Tônica/efeitos dos fármacos , Fitoterapia , Extratos Vegetais/administração & dosagem , Verbenaceae/química , Animais , Depressão/tratamento farmacológico , Masculino , Camundongos , Estresse Psicológico/tratamento farmacológico , Natação/psicologiaRESUMO
The aim of the present work is to demonstrate the putative sedative and anxiolytic-like effects of a hydro-ethanolic extract obtained from the aerial parts of Aloysia polystachya (Verbenaceae) in male mice using several behavioural assays. Groups of male mice orally treated with doses of 1.0, 10.0 and 100.0 mg/kg of the extract did not show any significant alteration of their locomotor activity, body temperature or motor coordination. The same treatment increased the duration of the sleeping time induced by 30.0 mg/kg i.p. of sodium pentobarbital. However, the sleeping time induced by ethyl ether was not modified by the oral administration of the extract, not confirming the putative sedative effect of the plant. The ethanolic extract also significantly increased the percentage of both entries (1.0 and 100.0 mg/kg) and the time spent (10.0 and 100.0 mg/kg) into the open arms of the elevated plus maze (EPM). Nevertheless, the binding of (3)H-flunitrazepam ((3)H-FNZ) to the benzodiazepine binding site (BDZ-bs), in washed crude synaptosomal membranes from rat cerebral cortex, was not affected by the semi-purified components from Aloysia polystachya. These results indicate an anxiolytic-like profile of action for the extract of Aloysia polystachya without sedative side effect, being this activity probably mediated by other mechanism than BDZ-bs modulation at the GABA(A) receptors.
Assuntos
Ansiolíticos/farmacologia , Extratos Vegetais/farmacologia , Verbenaceae , Animais , Comportamento Animal/efeitos dos fármacos , Temperatura Corporal/efeitos dos fármacos , Flunitrazepam/metabolismo , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Atividade Motora/efeitos dos fármacos , Sono/efeitos dos fármacosRESUMO
The crude hydroalcoholic root extract (CRE) of Solanum sisymbriifolium Lam. has formerly been shown to have hypotensive activity both in normo-and hypertensive rats. Hypotensive activity-guided fractionation of the CRE was performed in anaesthetized normotensive rats, which led to the isolation of the active principles. The intravenous (i.v.) and intraperitoneal (i.p.) values of the CRE in mice were found to be, respectively, 343 and 451 mg/kg, and no lethal effect was caused by doses up to 5.0 g/kg when administered by oral route. Depression of locomotion, increase of breathing rate and piloerection was observed in a general behavior test with doses up to 200 mg/kg i.p., and 1000 mg/kg p.o., respectively. Increase in the gastrointestinal transit was found using 0.1 g/kg, whereas at doses of 0.5 and 1 g/kg, no significant activity was observed in comparison with the control mice. Hexanic and butanolic fractions induced a remarkable hypotension in anaesthetized normotensive rats in doses of 1, 5, 7.5 and 10 mg/kg i. v. Two compounds isolated from the butanolic fraction induced a significant decrease of the blood pressure, HR, amplitude of the ECG and breathing rate when injected in a dose of 1 mg/kg i.v; and both systofic and diastolic, blood pressures were affected in a proportional mode. The hypotensive effect of the two compounds were not influenced by pretreatment with atropine and propranolol; and the pressor response to noradrenaline was not affected by any of them which suggests that neither a direct muscarinic activity, beta-adrenoceptor activation nor decrease of sympathetic vascular tone (sympatholitic activity) are probably involved in the mechanism of hypotension. The present study shows that the CRE of S. sisymbriifolium contains at least two hypotensive compounds whose characterization is under way.
Assuntos
Anti-Hipertensivos/farmacologia , Plantas Medicinais/química , Animais , Anti-Hipertensivos/isolamento & purificação , Anti-Hipertensivos/toxicidade , Comportamento Animal/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Cromatografia em Camada Fina , Eletrocardiografia/efeitos dos fármacos , Feminino , Trânsito Gastrointestinal/efeitos dos fármacos , Dose Letal Mediana , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ratos , Ratos Wistar , Mecânica Respiratória/efeitos dos fármacosRESUMO
Acute toxicity and general pharmacological activities of the crude hydro-alcoholic rhizome extract of Kyllinga brevifolia Rottb., a popular medicine used in Paraguay, were investigated on mice. The intraperitoneal LD50 was found to be 575 mg/kg. Oral administration of doses up to 3.0 g/kg did not provoke any toxic symptoms. Oral administration of 100 mg/kg of the extract induced a significant increase in gastrointestinal transit. In open field studies, a decrease of spontaneous locomotor activity, piloerection, passivity, palpebral ptosis, catatonia and a stereotyped behaviour was produced by the extract when administered orally (1, 10 and 100 mg/kg). A significant decrease in respiration rate was observed (1, 10 and 100 mg/kg, p.o.) using a continuous flow respiration system. Lastly, doses of 1, 10 and 100 mg/kg, p.o. of the extract produced a significant increase in the hypnotic effect induced by pentobarbital in a dose-dependent manner. The latest effects could probably explain its rational use in traditional medicine to alleviate stress or as a sedative agent.