(1) Background: Thymoquinone (TQ) is the leading compound accounting for the pharmacological effects of Nigella sativa seed oil, also known as black seed oil. This study aimed to analyze the TQ content of commercial black seed oils and black seed oil-containing capsules to obtain information on the quality of the products and to find a promising and safe study medication for a putative clinical study. (2) Methods: Six black seed oils and five black seed oil-containing capsules were analyzed.
View Article and Find Full Text PDFMatcha tea contains only the softer parts of the tea leaves and is finely ground. Therefore, extraction of the flavanols for analysis by HPLC is possible by a simpler protocol compared to the ISO 14502-2 method. 21 different simplified extraction methods were screened and five of them gave equal results as the ISO 14502-2 method.
View Article and Find Full Text PDFObjective: To assess the safety and efficacy of epigallocatechin-3-gallate (EGCG) add-on to glatiramer acetate (GA) in patients with relapsing-remitting multiple sclerosis (RRMS).
Methods: We enrolled patients with RRMS (aged 18-60 years, Expanded Disability Status Scale [EDSS] score 0-6.5), receiving stable GA treatment in a multicenter, prospective, double-blind, phase II, randomized controlled trial.
Improvement of endothelial function represents a major health effect of tea in humans. Ex vivo, tea and tea polyphenols stimulate nitric oxide (NO)-dependent vasodilation in isolated blood vessels. However, it was reported that polyphenols can generate reactive oxygen species (ROS) in vitro.
View Article and Find Full Text PDFCocoa has been used as a ceremonial and hedonistic food for thousands of years in the tropical parts of America and for hundreds of years in the western world. […].
View Article and Find Full Text PDFFlavan-3-ols are claimed to be responsible for the cardioprotective effects of cocoa. Alkalized cocoa powder (ALC), commonly used for many non-confectionary products, including beverages, provides less (+)-catechin, (-)-epicatechin, and procyanidins and more (-)-catechin than nonalkalized cocoa powder (NALC). This may affect the plasma appearance of monomeric flavan-3-ol stereoisomers after consumption of NALC vs.
View Article and Find Full Text PDFRandomized controlled trials indicate that flavanol-rich cocoa intake may improve postprandial glucose and lipid metabolism in patients with type 2 diabetes (T2D), based on studies with meals that impose a strong metabolic load. Hence, the aim of the present study was to investigate whether flavanol-rich cocoa powder ingested as part of a diabetic-suitable meal may beneficially affect glucose, lipid metabolism, and blood pressure (BP) in patients with T2D. Twelve adults with T2D, overweight/obesity, and hypertension ingested capsules with 2.
View Article and Find Full Text PDFRegular cocoa consumption has been shown to improve blood pressure (BP), insulin sensitivity, and lipid levels in patients with type 2 diabetes (T2D), using up to 100 g of chocolate or 54 g of cocoa. These effects, attributed to cocoa flavanols, would be beneficial for patients with T2D if they could be achieved by a usual serving size of flavanol-rich cocoa. Forty-two hypertensive patients with T2D (stable pharmacological treatment, with good adjustment for glucose metabolism, lipids, and BP) ingested capsules with 2.
View Article and Find Full Text PDFThe aim of the present study was to investigate the bioavailability of quercetin from onion bulb (OB) and onion skin (OS) extracts in ruminants. Three non-lactating cows equipped with a permanent rumen fistula intraruminally received equimolar amounts of quercetin as either aglycone, rutin, or OB or OS extract, respectively, at a dose of 50 mg of quercetin equivalents/kg of body weight. Blood samples were drawn before and frequently within the 24 h period after application of the respective substance.
View Article and Find Full Text PDFBackground: Regular cocoa consumption has been shown to reduce blood pressure, improve lipid profiles, and increase insulin sensitivity and flow-mediated dilatation in healthy adults. It is assumed that these effects can be attributed to polyphenolic cocoa ingredients such as flavanols, especially to (-)-epicatechin. Nutritive intervention studies to prove this hypothesis are scarce.
View Article and Find Full Text PDFScope: After intrinsic labeling of spinach (Spinacia oleracea L., Chenopodiaceae) with CO , we investigated if labeled polyphenol metabolites were detectable in human plasma.
Methods And Result: In a pilot intervention trial, five healthy men consumed 5 g freeze-dried C labeled spinach, including a total amount of 160 μmol methoxyflavonols, including 70 μmol 5,3',4'-trihydroxy-3-methoxy-6,7-methylendioxyflavone-4'-glucuronide.
Pink guava (Psidium guajava L.) is a highly consumed fruit in tropical countries. Despite of interesting research on health effects of this fruit, investigations into the profile of secondary plant metabolites are scarce.
View Article and Find Full Text PDFNine state-of-the-art reversed phase (RP) columns for ultra-high performance liquid chromatography were tested for the separation of steviol glycosides. The main criteria were resolution of the critical peak pair rebaudioside A and stevioside and the retention time of rebaudioside D. Three columns yielded a resolution of 2 or more of the critical peak pair and two of them showed sufficient retention of rebaudioside D, namely 1.
View Article and Find Full Text PDFAlkylresorcinols (ARs) occur in bran of cereals and in fruits from the Anacardiaceae family. Their separation by liquid chromatography is challenging, especially in rye (Secale cereale L.) that has a complex AR composition.
View Article and Find Full Text PDFConsumption of tea is inversely associated with cardiovascular diseases. However, the active compound(s) responsible for the protective effects of tea are unknown. Although many favorable cardiovascular effects in vitro are mediated by epigallocatechin gallate (EGCG), its contribution to the beneficial effects of tea in vivo remains unresolved.
View Article and Find Full Text PDFThe objectives of this work were to determine the phenolic profile of Schinus terebinthifolius and Schinus molle fruits and to develop a reliable method for the differentiation of these two similar spices both known as pink pepper. Anthocyanins, biflavonoids and gallotannins, some of which are reported for the first time in these species, were identified by UHPLC-UV/vis-MS/MS. Consideration of the relative and absolute amounts of phenolics as well as indicator compounds from 18 samples revealed that the relative amounts of anthocyanins and biflavonoids are the most trustworthy parameters.
View Article and Find Full Text PDFResponse surface methodology was employed to investigate the effects of pressurized liquid extraction (PLE) parameters on the recovery of phenolic compounds (anthocyanins, biflavonoids) from Brazilian pepper (Schinus terebinthifolius Raddi) fruits. The effects of temperature, static time, and ethanol as well as acid concentration on the polyphenol yield were described well by quadratic models (p<0.0001).
View Article and Find Full Text PDFFast methods for the extraction and analysis of various secondary metabolites from cocoa products were developed and optimized regarding speed and separation efficiency. Extraction by pressurized liquid extraction is automated and the extracts are analyzed by rapid reversed-phase ultra high-performance liquid chromatography and normal-phase high-performance liquid chromatography methods. After extraction, no further sample treatment is required before chromatographic analysis.
View Article and Find Full Text PDFThe aim of the study was to review the effect of cocoa flavanols on cardiovascular health, with emphasis on the doses ingested, and to analyze a range of cocoa products for content of these compounds. PubMed was searched from 2010 to locate systematic reviews (SR) on clinical effects of chocolate consumption. Thirteen SRs were identified and reviewed, and provided strong evidence that dark chocolate did not reduce blood pressure.
View Article and Find Full Text PDFSunflower extraction meal (SEM) is an economically interesting protein source. During alkaline extraction of proteins, the presence of chlorogenic acid (CQA) in the meal gives rise to the formation of o-quinones. Reactions with nucleophiles present in proteins can lead to green discoloration.
View Article and Find Full Text PDFPurpose: To investigate the plasma kinetics of quercetin derived from hard capsules filled with onion skin extract powder or quercetin dihydrate in humans.
Methods: In a randomized, single-blind, diet-controlled crossover study, 12 healthy subjects (six men and six women) aged 21-33 years were administered a single oral supra-nutritional dose of approximately 163 mg quercetin derived from onion skin extract powder (containing 95.3 % of total flavonoids as quercetin aglycone) or quercetin dihydrate (134 mg quercetin aglycone equivalent).
Br J Nutr
October 2015
The polyphenol quercetin may prevent CVD due to its antihypertensive and vasorelaxant properties. We investigated the effects of quercetin after regular intake on blood pressure (BP) in overweight-to-obese patients with pre-hypertension and stage I hypertension. In addition, the potential mechanisms responsible for the hypothesised effect of quercetin on BP were explored.
View Article and Find Full Text PDFMost research on American cranberry in the prevention of urinary tract infection (UTI) has used juices. The spectrum of components in juice is limited. This study tested whether whole cranberry fruit powder (proanthocyanidin content 0.
View Article and Find Full Text PDFThe aim of our study was to determine the antioxidant activities, cytotoxicity and proliferative properties in Stevia rebaudiana leaves and stems. Leaves extracts exhibited a higher antioxidant activity than stems extract, through oxygen radical absorbance capacity (ORAC) and cellular antioxidant activity (CAA) assays. Stevioside and rebaudioside A, the main sweetening metabolites in stevia leaves, exhibited a low ORAC value in comparison with plant extracts, while did not elicit any CAA.
View Article and Find Full Text PDFEvid Based Complement Alternat Med
March 2015
Preclinical in vitro and in vivo studies demonstrate potent effects of pomegranate preparations in cancer cell lines and animal models with chemically induced cancers. We have carried out one systematic review of the effectiveness of pomegranate products in the treatment of cancer and another on their safety. The PubMed search provided 162 references for pomegranate and cancer and 122 references for pomegranate and safety/toxicity.
View Article and Find Full Text PDF