Grazielle C Silva1, Fernão C Braga2, Virgínia S Lemos3, Steyner F Cortes4. 1. Department of Pharmacology, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 31270-901 Belo Horizonte, MG, Brazil ; Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 31270-901 Belo Horizonte, MG, Brazil. 2. Department of Pharmaceutical Sciences, Faculty of Pharmacy, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 31270-901 Belo Horizonte, MG, Brazil. 3. Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 31270-901 Belo Horizonte, MG, Brazil. 4. Department of Pharmacology, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 31270-901 Belo Horizonte, MG, Brazil . Electronic address: sfcortes@icb.ufmg.br.
Abstract
BACKGROUND: Hancornia speciosa Gomes is an herb traditionally used in Brazil for blood pressure control. PURPOSE: The present work investigated the antihypertensive effect of an extract from Hancornia speciosa leaves (SFH) and analyzed its underlying mechanisms of action. METHODS: Hypertension was induced in mice by surgical removal of a kidney and by subcutaneous administration of a pellet with deoxycorticosterone. Vasodilatation was measured in mesenteric arteries with a wire myograph. Nitrites were measured by fluorescence with 2,3-diaminonaphthalene and H2O2 was measured with carbon microsensors. RESULTS: SFH (0.03, 0.1 or 1 mg/kg; po) induced a dose-dependent, long-lasting reduction in the systolic blood pressure in conscious DOCA-salt hypertensive mice (DOCA). Administration of SFH produced a significant increase in the plasmatic level of nitrites. The systemic inhibition of nitric oxide synthase by L-NAME (20 mg/kg) reduced its antihypertensive effect. SFH also induced a concentration-dependent vasodilatation of mesenteric resistance arteries contracted with phenylephrine, which was more potent in arteries from DOCA mice. Removal of the endothelium or pretreatment with L-NAME or catalase reduced the vasodilator response for SFH. The nitrite production induced by SFH was significantly bigger in mesenteric arteries from DOCA than in SHAM mice. However, the production of H2O2 induced by SFH was twice higher in DOCA mice. CONCLUSION: Altogether, our results point to an antihypertensive effect of SFH due to a reduction in peripheral resistance through the production of NO and by a mechanism involving an increased production of H2O2 in the mesenteric arteries from hypertensive mice. These findings are further evidence to support the use of Hancornia speciosa by traditional medicine as an antihypertensive drug.
BACKGROUND:Hancornia speciosa Gomes is an herb traditionally used in Brazil for blood pressure control. PURPOSE: The present work investigated the antihypertensive effect of an extract from Hancornia speciosa leaves (SFH) and analyzed its underlying mechanisms of action. METHODS:Hypertension was induced in mice by surgical removal of a kidney and by subcutaneous administration of a pellet with deoxycorticosterone. Vasodilatation was measured in mesenteric arteries with a wire myograph. Nitrites were measured by fluorescence with 2,3-diaminonaphthalene and H2O2 was measured with carbon microsensors. RESULTS:SFH (0.03, 0.1 or 1 mg/kg; po) induced a dose-dependent, long-lasting reduction in the systolic blood pressure in conscious DOCA-salthypertensivemice (DOCA). Administration of SFH produced a significant increase in the plasmatic level of nitrites. The systemic inhibition of nitric oxide synthase by L-NAME (20 mg/kg) reduced its antihypertensive effect. SFH also induced a concentration-dependent vasodilatation of mesenteric resistance arteries contracted with phenylephrine, which was more potent in arteries from DOCAmice. Removal of the endothelium or pretreatment with L-NAME or catalase reduced the vasodilator response for SFH. The nitrite production induced by SFH was significantly bigger in mesenteric arteries from DOCA than in SHAM mice. However, the production of H2O2 induced by SFH was twice higher in DOCAmice. CONCLUSION: Altogether, our results point to an antihypertensive effect of SFH due to a reduction in peripheral resistance through the production of NO and by a mechanism involving an increased production of H2O2 in the mesenteric arteries from hypertensivemice. These findings are further evidence to support the use of Hancornia speciosa by traditional medicine as an antihypertensive drug.
Authors: Uilson Pereira Dos Santos; Georgina S Tolentino; Jorge Sá Morais; Kely de Picoli Souza; Leticia M Estevinho; Edson Lucas Dos Santos Journal: Oxid Med Cell Longev Date: 2018-06-28 Impact factor: 6.543