DEFAR - Artigos publicados em periódicos

URI permanente para esta coleçãohttp://www.hml.repositorio.ufop.br/handle/123456789/531

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2005 - 20104

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Autor: search.filters.author.Braga, Fernão Castro

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Agora exibindo 1 - 4 de 4
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    Angiotensin-converting enzyme inhibition by Brazilian plants.
    (2007) Braga, Fernão Castro; Serra, Carla Penido; Viana Júnior, Nilton de Souza; Oliveira, Alaíde Braga de; Côrtes, Steyner de França; Lombardi, Júlio Antônio
    The potential antihypertensive activity of Brazilian plants was evaluated in vitro by its ability to inhibit the angiotensinconverting enzyme (ACE). Forty-four plants belonging to 30 families were investigated. Plants were selected based on their popular use as antihypertensive and/or diuretics. The following plants presented significant ACE inhibition rates: Calophyllum brasiliense, Combretum fruticosum, Leea rubra, Phoenix roebelinii and Terminalia catappa.
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    Validation of a colorimetric assay for the in vitro screening of inhibitors of angiotensin-converting enzyme (ACE) from plant extracts.
    (2005) Serra, Carla Penido; Côrtes, Steyner de França; Lombardi, Júlio Antônio; Oliveira, Alaíde Braga de; Braga, Fernão Castro
    Anew method for the in vitro screening of plant extracts with potential angiotensin-converting enzyme (ACE) inhibitory activity is proposed. The method is based on the cleavage of the substrate hippuryl-glycyl-glycine by ACE and subsequent reaction with trinitrobenzenesulfonic acid to form 2,4,6-trinitrophenyl-glycyl-glycine, whose absorbance is determined at 415nm in a microtitre plate reader. Rabbit lung dehydrated by acetone was employed as an enzyme source. Validation of the method showed satisfactory intra-day (CV ¼ 7.63%) and inter-day precision (CV ¼ 13.61%), recovery (97–102.1%), sensitivity (IC50 ¼ 14.1 nmol/l) and linearity in the range 7.5–120 mmol/l of glycyl-glycine (r2 ¼ 0:9921). Besides, the method showed good correlation with a HPLC assay already established for the screening of ACE inhibitors (r ¼ 0:9935 and 0:9034; respectively, for captopril solutions and for plant extracts). The method involves only inexpensive reagents and apparatus.
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    ACE inhibition by astilbin isolated from Erythroxylum gonocladum (Mart.) O.E. Schulz.
    (2010) Lucas Filho, Milton Dayrell; Silva, Grazielle Caroline da; Côrtes, Steyner de França; Guia, Thiago Rennó dos Mares; Ferraz, Vany Perpetua; Serra, Carla Penido; Braga, Fernão Castro
    Erythroxylum species have several traditional uses in different countries, including the treatment of hypertension. The ethanol extract from E. gonocladum aerial parts, a species endemic to the Brazilian cerrado, elicited a concentration-dependent inhibition of angiotensin converting enzyme (ACE) (pIC50=4.53±0.05). Extract fractionation led to the isolation of two compounds, whose structures were assigned by spectrometric data as astilbin and β-sitosterol, along with a mixture of palmitic, stearic and linolenic acids. This is the first report on the occurrence of these compounds on E. gonocladum. Astilbin promoted significant ACE inhibition in vitro (pIC50=5.86±0.33) and its activity did not differ from captopril, when both compounds were assayed at 10 μM concentration.
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    Endothelium-dependent vasodilation induced by Hancornia speciosa in rat superior mesenteric artery.
    (2007) Ferreira, Herick Campos; Serra, Carla Penido; Endringer, Denise Coutinho; Lemos, Virgínia Soares; Braga, Fernão Castro; Côrtes, Steyner de França
    The vasodilator effect of the ethanolic extract of leaves from Hancornia speciosa Gomes (HSE) was evaluated in superior mesenteric artery rings. HSE produced a concentration-dependent vasodilation (IC50 ¼ 10.874.0 mg/mL) in arterial rings pre-contracted with phenylephrine, which was completely abolished in endothelium-denuded vessels. Endothelium-dependent vasodilation induced by HSE was strongly reduced by L-NAME (100 mM), a nitric oxide (NO) synthase inhibitor, but neither by atropine, a muscarinic receptor antagonist (1 mM), nor by indomethacin (10 mM), a cyclooxygenase inhibitor. In rings pre-contracted with 80mM KCl, the vasodilator effect of HSE was shifted to the right and was completely abolished in the presence of L-NAME (100 mM). Similar effects were obtained in mesenteric rings pre-contracted with phenylephrine in the presence of KCl 25mM alone or in addition to 100 mM L-NAME.In addition, BaCl2 (1mM) dramatically reduced the vasodilation induced by HSE. Together, these findings led usv to conclude that HSE induces an endothelium-dependent vasodilation in rat mesenteric artery, by a mechanism dependent on NO, on the activation of potassium channels and endothelium-derived hyperpolarizing factor release. Rutin, identified as a major peak in the HPLC fingerprint obtained for HSE, might contribute for the observed vasodilator effect, since it was able to induce an endothelium-dependent vasodilation in rat superior mesenteric arteries.