RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Celosia argentea L. (Amaranthaceae), popularly known as "crista de galo", is used in folk medicine due to its diuretic and hypotensive effects. However, there are no reports in the literature regarding its pharmacological effects on the cardiovascular system as well as no data proving the safety of this species. AIM: To perform a detailed ethnopharmacological investigation of the ethanol soluble fraction from C. argentea (ESCA) using male and female Wistar rats. MATERIAL AND METHODS: Firstly, a morpho-anatomical characterization was performed to determine the quality control parameters for the identification of the species under investigation. Then, the ethanol extract was obtained and chemically characterized by LC-DAD-MS. Furthermore, an oral acute toxicity study was performed in female Wistar rats. Finally, the possible diuretic and hypotensive effects of three different doses of ESCA (30, 100 and 300â¯mg/kg) were evaluated in male Wistar rats. Besides, the vasodilatory response of ESCA in mesenteric vascular beds (MVBs) and its involvement with nitric oxide/cGMP and prostaglandin/cAMP pathways as well as potassium channels were evaluated. RESULTS: The main secondary metabolites present in ESCA were phenolic compounds, megastigmanes and triterpenoid saponins. ESCA caused no toxic effects in female rats nor increased urinary excretion in male rats after acute administration. However, ESCA significantly increased the renal elimination of potassium and chloride, especially at the end of 24â¯h after administration. Intermediary dose (100â¯mg/kg) of ESCA was able to promote significant acute hypotension and bradycardia. Moreover, its cardiovascular effects appear to be involved with the voltage-dependent K+ channels activation in MVBs. CONCLUSION: This study has brought new scientific evidence of preclinical efficacy of C. argentea as a hypotensive agent in normotensive rats. Apparently, these effects are involved with the activation of the voltage-sensitive K+ channels contributing to the reduction of peripheral vascular resistance and cardiac output.
Assuntos
Anti-Hipertensivos/farmacologia , Celosia , Extratos Vegetais/farmacologia , Vasodilatadores/farmacologia , Animais , Pressão Arterial/efeitos dos fármacos , Brasil , Celosia/química , Etnofarmacologia , Feminino , Frequência Cardíaca/efeitos dos fármacos , Masculino , Extratos Vegetais/química , Folhas de Planta , Canais de Potássio de Abertura Dependente da Tensão da Membrana/fisiologia , Ratos Wistar , Testes de Toxicidade Aguda , Resistência Vascular/efeitos dos fármacos , Vasodilatadores/químicaRESUMO
Se realizó un estudio de intervención terapéutica, con vistas a evaluar el efecto de la acupuntura en 1000 pacientes con glaucoma, los cuales fueron intervenidos quirúrgicamente en el Centro Oftalmológico del Hospital General Docente "Dr. Juan Bruno Zayas Alfonso" de Santiago de Cuba, desde enero de 2009 hasta igual mes de 2011. La casuística quedó distribuida en 2 grupos: de estudio y control, con 500 integrantes cada uno, los primeros tratados con acupuntura y los segundos con hipotensores sistémicos. En 96,0 % del grupo de estudio, se obtuvieron cifras de presión intraocular por debajo de 21 mm de Hg y la analgesia posoperatoria resultó ser muy satisfactoria en 90,0 % de los casos. Asimismo los resultados del tratamiento acupuntural favorecieron a 463 pacientes (93,0 %).
A therapeutic intervention study was conducted to evaluate the effect of the acupuncture on 1000 patients with glaucoma, who underwent surgery at the Ophthalmology Center of «Dr. Juan Bruno Zayas Alfonso¼ General Teaching Hospital in Santiago de Cuba, from January 2009 to January 2011. The case material was distributed into 2 groups: study and control groups, with 500 patients each; the former treated with acupuncture and the latter with systemic hipotensive agents. Intraocular pressure values below 21 mm Hg were obtained in 96.0 % of the study group and postoperative analgesia was very satisfactory in 90.0 % of the cases. Thus, the results of the acupuncture treatment favored 463 patients (93.0 %).
RESUMO
Inhibition of Angiotensin Converting Enzyme (ACE) is a modern therapeutic target in the treatment of hypertension. Within the enzyme cascade of the renin-angiotensin system, ACE removes histidyl-leucine from angiotensin I to form the physiologically active octapeptide angiotensin II, one of the most potent known vasoconstrictors. Therefore, a rationale for treating hypertension would be to administer drugs or natural compounds which selectively inhibit ACE. The present work constitutes a review of the literature of plants and chemically defined molecules from natural sources with in vitro anti-hypertensive potential based on the inhibition of ACE. The review refers to 321 plants, the parts utilized, type of extract and whether they are active or not. It includes also the names of 158 compounds isolated from higher plants, marine sponges and algae, fungi and snake venom. Some aspects of recent research with natural products directed to produce anti-hypertensive drugs are discussed. In this review, 148 references were cited.
A inibição da Enzima Conversora da Angiotensina (ECA) é um alvo terapêutico moderno e eficaz no tratamento da hipertensão arterial. Na cascata enzimática que envolve o sistema renina-angiotensina, a ECA promove a remoção dos aminoácidos histidil-leucina da angiotensina I para formar o octapeptídio angiotensina II, a qual é fisiologicamente ativa em diversos sistemas, e considerado como um dos mais potentes vasoconstrictores endógenos conhecido. Portanto, uma racionalidade no tratamento da hipertensão seria administrar drogas ou compostos de origem natural que inibam seletivamente a ECA. O presente estudo constitui uma revisão da literatura sobre plantas e moléculas de origem natural com potencial anti-hipertensivo, baseado na inibição in vitro da ECA. A revisão referencia 321 plantas, partes usadas, tipo de extrato e se é ativo ou não. Inclui ainda o nome de 158 compostos isolados de plantas superiores, esponjas e algas marinhas, fungos e venenos de cobra. Alguns aspectos de pesquisa recente com produtos naturais direcionados à produção de drogas anti-hipertensivas também são discutidos. Nesta revisão 148 referências foram consultadas.