RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Talinum paniculatum (Jacq.) Gaertn. (Talinaceae), popularly known as "major gomes" and "erva gorda", is a non-conventional food plant extensively distributed throughout the Brazilian territory. In Brazilian folk medicine, this species is used as aphrodisiac, to treat gastrointestinal problems, and as a cardioprotective agent. However, there are no reports in the literature proving its cardiovascular effects. AIM: To perform a whole-ethnopharmacological investigation of the cardiorenal properties of the ethanol soluble fraction from T. paniculatum (ESTP) in Wistar rats. MATERIAL AND METHODS: First, plant samples were collected, properly identified and a morpho-anatomical characterization was carried out to provide quality control parameters. Then, ESTP was obtained and its chemical profile was determined by LC-DAD-MS. In addition, an acute toxicity assay was conducted in female Wistar rats in order to observe any toxic effects after one single administration. Finally, the diuretic and hypotensive potential of ESTP (30, 100 and 300â¯mg/kg) were investigated in male rats followed by the evaluation of its possible effects on peripheral vascular resistance. RESULTS: Chemical compounds identified from ESTP were chlorogenic acids, amino acids, nucleosides, O-glycosylated flavones and organic acids. No signs of toxicity as well as no changes in urine volume or electrolyte elimination were observed after ESTP acute treatment. On the other hand, prolonged treatment with all doses of ESTP significantly increased urine volume and electrolyte excretion (Na+, K+ and Cl-) without affecting blood pressure or heart rate. Apparently, these effects are involved with the activation of the small conductance calcium-activated potassium channels contributing to the increase of renal blood flow and glomerular filtration rate. CONCLUSION: Data presented show important information about the ethnomedicinal properties of T. paniculatum. In addition, the study presents the ESTP as a possible herbal medicine, especially when a sustained diuretic effect is required.
Assuntos
Pressão Sanguínea/efeitos dos fármacos , Diurese/efeitos dos fármacos , Etnofarmacologia , Frequência Cardíaca/efeitos dos fármacos , Magnoliopsida/química , Extratos Vegetais/farmacologia , Animais , Brasil , Cromatografia Líquida/métodos , Feminino , Masculino , Espectrometria de Massas/métodos , Fitoterapia , Extratos Vegetais/química , Folhas de Planta/química , Caules de Planta/anatomia & histologia , Plantas Medicinais , Ratos , Ratos WistarRESUMO
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
The loss of the modulator role of the endothelium could be involved in the pathogenesis of diabetic vascular complications. Transition metal compounds, such as tungsten and vanadium, have been proposed as possible agents in the treatment of diabetes by simulating the effects of insulin. The mesenteric vascular bed intervenes in vascular resistance and is a source of vasoactive compounds, such as prostanoids. The aim of this work was to study the effects of sodium tungstate and vanadyl sulphate treatments on the metabolic parameters and the release of prostanoids of the mesenteric vascular bed in an experimental model of Streptozotocin-induced diabetes. In diabetic rats, a significant increase was observed in plasma levels of glucose, triglycerides and total cholesterol. On the other hand, there was a significant reduction in the release of vasodilator prostanoids, such as prostacyclin and prostaglandin E2 and vasoconstrictor thromboxane A2 through the mesenteric vascular bed. Both sodium tungstate and vanadyl sulphate normalised glycaemia, triglyceridaemia and cholesterolaemia in rats diabetics. On the other hand, only treatment with sodium tungstate reversed the reduction in the release of vasodilator prostanoids, improving in diabetic animals the prostacyclin/thromboxane ratio, an indicator of vascular dysfunction. In conclusion, unlike vanadyl sulphate, sodium tungstate is shown to be more effective in controlling metabolic changes and the production of vasodilator prostanoids observed in experimental diabetes induced by streptozotocin.
Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Prostaglandinas/metabolismo , Compostos de Tungstênio/farmacologia , Compostos de Vanádio/farmacologia , Animais , Glicemia/efeitos dos fármacos , Diabetes Mellitus Experimental/fisiopatologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/patologia , Hipoglicemiantes/farmacologia , Masculino , Mesentério/irrigação sanguínea , Ratos , Ratos Wistar , EstreptozocinaRESUMO
Chronic fructose intake induces major cardiovascular and metabolic disturbances and is associated with the development of hypertension due to changes in vascular function. We hypothesized that high fructose intake for 6 weeks would cause metabolic syndrome and lead to initial vascular dysfunction. Male Wistar rats were assigned to receive fructose (FRU, 10%) or drinking water (CON) for 6 weeks. Systolic blood pressure was evaluated by tail plethysmography. Fasting glucose, insulin and glucose tolerance were measured at the end of the follow-up. Mesenteric vascular bed reactivity was tested before and after pharmacological blockade. Western blot analysis was performed for iNOS, eNOS, Nox2 and COX-2. DHE staining was used for vascular superoxide anion detection. Vessel structure was evaluated by optical and electronic microscopy. Fructose intake did not alter blood pressure, but did increase visceral fat deposition and fasting glucose as well as impair insulin and glucose tolerance. Fructose increased NE-induced vasoconstriction compared with CON, and this difference was abrogated by indomethacin perfusion as well as endothelium removal. ACh-induced relaxation was preserved, and the NO modulation tested after L-NAME perfusion was similar between groups. SNP-induced relaxation was not altered. Inducible NOS was increased; however, there were no changes in eNOS, Nox2 or COX-2 protein expression. Basal or stimulated superoxide anion production was not changed by fructose intake. In conclusion, high fructose intake increased NE-induced vasoconstriction through the endothelial prostanoids even in the presence of a preserved endothelium-mediated relaxation. No major changes in vessel structure were detected.