Aplicação da espectrometria de massas para o estudo químico da fração acetato do vinho tinto Syrah do Vale do São Francisco e estudo da sua atividade antioxidante e anti-hipertensiva

• Autor(a) principal: Figueiredo, Eugênia Abrantes de
• Data de Publicação: 2017
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/123456789/15028
• topic: Vinho; Fenólicos; Hipertensão; Wine; Phenolics; Hypertension; CNPQ::CIENCIAS BIOLOGICAS::FARMACOLOGIA

Wine has high levels of polyphenols which include both flavonoids and non-flavonoids. Epidemiological studies have demonstrated an association between the consumption of phenolics rich food and beverages and reduce risk of cardiovascular diseases. Hypertension is a major risk factor for cardiovascular disease. Among the factors associated with the development of hypertension, an extremely important and current issue is the participation of reactive oxygen species (ROS) in its pathogenesis. Thus, the aim of this study was to investigate the antioxidant and anti-hypertensive effect of a rich phenolic fraction derived from red wine (Syrah from the São Francisco Valley region), in spontaneously hypertensive rats. The wine was partitioned with EtOAc at different pHs yielding three fractions. The total phenolic content of wine and fractions was determined by the Folin-Ciocalteu method and expressed as milligrams of gallic acid equivalent per liter or per extract gram of extract (mg GAE/L; mg GAE/ g). The antiradicalar activity was determined using the DPPH (with ascorbic acid as positive control), the Trolox Equivalent Antioxidant Capacity (TEAC) or the ABTS•+ test (with Trolox as a positive control). The determination of monomeric anthocyanins was carried out by the differential pH method. The chromatographic profile and the determination and quantification of quercetin and trans-resveratrol was performed by HPLC-UV. Ultra High Performance Liquid Chromatography coupled with Electrospray Ionization High resolution Time of Flight Mass Spectrometry (UPLC-ESI-TOF) was used to identify the compounds present in pH 7 acetate fraction (FrAcOEt SyRe VSF). Spontaneously hypertensive rats (SHR) were divided into 4 groups (n=32): SHR + saline (n = 8); SHR + FrAcOEt pH 7 Syre ESV (50 mg/kg) (n = 8); SHR + saline (n = 8); SHR + FrAcOEt pH 7 Syre ESV (100 mg/kg) (n = 8) and treated with the respective daily doses V.O. by gavage for two weeks. 24h after cannulation blood pressure, heart rate were recorded and baroreflex stimulated. Oxidative stress was measured via lipid peroxidation (TBARS). Superior mesenteric artery rings isolated from normotensive rats were used to evaluate the vasorelaxant effect of FrAcOEt pH 7 SyRe VSF. The FrAcOEt pH 7 SyRe VSF had the largest total phenolic content (58.45 ± 0.01 mg GAE/g) and monomeric anthocyanins (4.99 ± 0.019 mg/L) compared to other fractions. In addition it showed the best antioxidant activity against the DPPH and ABTS radical. The quercetin content and transresveratrol in FrAcOEt pH 7 SyRe VSF were respectively: 8.56 ± 0.078 and 1.11 ± 0.009 mg/mL. The UPLC/MS analysis of FrAcOEt pH 7 SyRe VSF allowed the identification of 13 compounds, including phenolic acids and flavonoids of various classes. Treatment of animals with FrAcOEt pH 7 SyRe VSF at 50 mg/kg and 100 mg/kg significantly reduced blood pressure when compared to the control group (146.1 ± 4.062 n = 7 vs 159.0 ± 3.891 n = 7, respectively) and (126.5 ± 5.322 n = 8 3.039 ± 150.0 vs. n = 7, respectively). Only at 100 mg/kg the fraction was able to significantly decrease the heart rate compared to the control group (314.6 ± 9.507 n = 8, 358.6 ± 15.00 n = 7, respectively) and to decrease lipid peroxidation (0.9250 nmol/L ± 0.1750 n = 4 vs. 2.180 nmol/L ± 0.3891 n = 5, respectively. There was no improvement in baroreflex sensitivity in neither dose. The cumulative addition of FrAcOEt pH 7 SyRe VSF caused vasorelaxation independent on the presence of vascular endothelium, with Emax = 103.7 ± 9.9% n = 7 in the presence of endothelium and Emax = 105.6 ± 5.9% n = 6 in the absence of endothelium. Thus, such results highlight the efficacy of the extraction process and suggest that FrAcOEt pH 7 SyRe VSF induces an in vivo antihypertensive effect and that this effect may be related to the content of phenolic compounds present in the fraction, even though probably some polyphenols present in wine and important for the biological effects observed here were concentrated in the other fractions not evaluated in this study. In addition, the in vitro activity observed for FrAcOEt pH 7 SyRe VSF, inducing vasorelaxant effect independent of vascular endothelium, probably involves calcium channel blockade and potassium channel opening.