ABSTRACT
Barley tea (Mugicha), commonly consumed in Japan and other East Asian countries, is prepared by decocting roasted barley (Hordeum vulgare) seed with hot or cold water. Although barley tea is commonly consumed, studies on its health benefits are limited, especially regarding its bioactivity against thrombosis. During the evaluation of functional foods and drinks, barley tea extract was found to exhibit potential fibrinolysis-enhancing activity induced by urokinase. Therefore, the aim of this study was to explore the application of barley tea as a functional food and conduct a preliminary investigation to reveal the effects of barley tea on thrombosis. Hot water extract of roasted barley was treated with pancreatin and separated via various techniques using macroporous resin and silica gel and tangential flow filtration with an ultra-filtration membrane. The low-molecular-weight fraction of the roasted barley tea extract was found to possess activity. We further purified the extract and found that the activity of each fraction decreased. Thus, the different fractions of the roasted barley extract may not exhibit the activity individually, instead additive or synergistic effects of multiple components may occur. The results suggest the potential use of barley extract as a functional food to prevent thrombosis.
Subject(s)
Hordeum , Fibrinolysis , Hot Temperature , Tea , Water , HumansABSTRACT
The candidates responsible for vasorelaxation action of rutin-free tartary buckwheat extract (TBSP) were examined in this study. As a result of reversed-phase high-performance liquid chromatography (HPLC) separations, five prominent peaks in the acidic fraction of TBSP were obtained at 260 nm. Among the five collected peaks, we successfully identified four compounds by nuclear magnetic resonance (NMR) and mass spectrometry (MS) measurements: (+)-osbeckic acid as a dimer ([M - H](-) m/z: 371.2 > 184.9 > 140.9), 5-hydroxymethyl-2-furoic acid, protocatechuic acid, and p-hydroxybenzoic acid. A vascular contractive measurement in 1.0 µM phenylephrine-contracted Sprague-Dawley rat thoracic aorta rings revealed that (+)-osbeckic acid dimer evoked a potent vasorelaxant effect with an EC50 value of 887 µM compared to other isolates (EC50: 5-hydroxymethyl-2-furoic acid, 3610 µM; protocatechuic acid, 2160 µM; p-hydroxybenzoic acid, no inhibition). Dimeric (+)-osbeckic acid was stable in solutions and at high temperatures, while its degraded peak on the HPLC chromatogram was observed when it was dissolved in dimethyl sulfoxide.
Subject(s)
Fagopyrum/chemistry , Furans/chemistry , Furans/pharmacology , Plant Extracts/chemistry , Plant Extracts/pharmacology , Vasodilation/drug effects , Vasodilator Agents/chemistry , Vasodilator Agents/pharmacology , Animals , Aorta, Thoracic/drug effects , Aorta, Thoracic/physiology , Furans/isolation & purification , In Vitro Techniques , Isomerism , Male , Plant Extracts/isolation & purification , Rats, Sprague-Dawley , Rutin/analysis , Seeds/chemistry , Vasodilator Agents/isolation & purificationABSTRACT
The aim of this study was to point out the potential of tartary buckwheat on vascular functions. A nonabsorbed fraction of hot-water extract of tartary buckwheat on a SP70 column (TBSP-T), which was free from rutin, was used for this aim. In a contractile experiment using Sprague-Dawley rat thoracic aorta rings contracted by 1.0 microM phenylephrine (PE) or 50 mM KCl, TBSP-T evoked a significant vasorelaxation [EC50 (mg/ml): PE; 2.2; KCl, 1.9]. By a further fractionation of TBSP-T by liquid-liquid partitioning into basic, neutral and acidic fractions, a marked enhancement of vasorelaxation effect was observed only for acidic fraction (EC50, 0.25 mg/ml). The action of acidic fraction was significantly attenuated in endothelium-denuded aortic rings and in the presence of nitric oxide synthase inhibitor, NG-monomethyl-L-arginine (100 microM). The fraction also enhanced the cyclic guanosine monophosphate (cGMP) production in aortic rings contracted with PE [cGMP (pmol/mg protein): PE, 7.2+/-2.3; PE+Acidic fraction, 35+/-8]. These results indicate that acidic fraction could mediate NO/cGMP pathways, thereby exerting endothelium-dependent vasorelaxation action. In conclusion, tartary buckwheat was proven to regulate vascular tones and have latent acidic candidates except for rutin.
Subject(s)
Aorta, Thoracic/drug effects , Endothelium, Vascular/drug effects , Fagopyrum/chemistry , Plant Extracts/pharmacology , Rutin/chemistry , Vasodilation/drug effects , Animals , Aorta, Thoracic/physiology , Endothelium, Vascular/physiology , Free Radical Scavengers/chemistry , Free Radical Scavengers/pharmacology , In Vitro Techniques , Plant Extracts/chemistry , RatsABSTRACT
Banaba [Lagerstroemia speciosa (L.) Pers.] has been used as a folk medicine for diabetes in the Philippines. Using bioassay-guided separation, valoneaic acid dilactone (1) was isolated from the leaves as a potent alpha-amylase inhibitor. A simple and efficient method for the quantitative determination of valoneaic acid and its derivatives in Banaba extract was established. Valoneaic acid exists as the structural part of the polyphenols, which like flosin A, reginin A, and lagerstroemin, are characteristic constituents of Banaba. These derivatives were hydrolyzed to valoneaic acid by HCl and extracted with 2-butanone. This extract was subjected to HPLC analysis, and the contents of valoneaic acid determined as the whole valoneaic acid contents. Using this method, the whole valoneaic acid contents were measured in eight Banaba leaf decoctions. The alpha-amylase-inhibiting activities of the decoctions were dependent on the whole valoneaic acid contents. In addition, a strong linear correlation was observed between the whole valoneaic acid contents and total polyphenol contents. This analytical procedure is applicable to the chemical evaluation of Banaba.
