Search

Scope: The Phenol-Explorer web database details 383 polyphenol metabolites identified in human and animal biofluids from 221 publications. Here, we exploit these data to characterize and visualize the polyphenol metabolome, the set of all metabolites derived from phenolic food components., Methods and Results: Qualitative and quantitative data on 383 polyphenol metabolites as described in 424 human and animal intervention studies were systematically analyzed. Of these metabolites, 301 were identified without prior enzymatic hydrolysis of biofluids, and included glucuronide and sulfate esters, glycosides, aglycones, and O-methyl ethers. Around one-third of these compounds are also known as food constituents and corresponded to polyphenols absorbed without further metabolism. Many ring-cleavage metabolites formed by gut microbiota were noted, mostly derived from hydroxycinnamates, flavanols, and flavonols. Median maximum plasma concentrations (C(max)) of all human metabolites were 0.09 and 0.32 μM when consumed from foods or dietary supplements, respectively. Median time to reach maximum plasma concentration in humans (T(max)) was 2.18 h., Conclusion: These data show the complexity of the polyphenol metabolome and the need to take into account biotransformations to understand in vivo bioactivities and the role of dietary polyphenols in health and disease., (© 2015 The Authors. Molecular Nutrition & Food Research published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Background: Chronic red wine (RW) consumption has been associated with decreased cardiovascular disease risk, mainly attributed to an improvement in lipid profile. RW intake is also able to change the composition of gut microbiota. High fat intake has recently been reported to increase metabolic endotoxemia. The gut microbiota has been proposed as the main resource of plasma lipopolysaccharides (LPSs) in metabolic endotoxemia., Objective: We analyzed the effect on LPS concentrations of chronic RW consumption and acute RW intake in relation to high fat intake in middle-aged men., Design: For the chronic study, 10 middle-aged male volunteers were randomly assigned in a crossover trial, and after a washout period, all subjects received RW, dealcoholized red wine (DRW), or gin for 20 d. Serum endotoxin and LPS-binding protein (LBP) concentrations were determined after the washout period and after each of the treatments, and changes in fecal microbiota were quantified. For the acute study, 5 adult men underwent a fat overload or a fat overload together with the consumption of RW, DRW, or gin. Baseline and postprandial serum LPS and LBP concentrations and postprandial chylomicron LPS concentrations were measured., Results: There were no significant differences in the change in LPS or LBP concentrations between chronic RW, DRW, and gin consumption. Bifidobacterium and Prevotella amounts were significantly increased by RW and correlated negatively with LPS concentrations. There were no differences in postprandial serum LPS, LBP, or chylomicron LPS concentrations between acute RW, DRW, or gin intake together with a fatty meal., Conclusion: Chronic RW consumption increases Bifidobacterium and Prevotella amounts, which may have beneficial effects by leading to lower LPS concentrations. This trial was registered at controlled-trials.com as ISRCTN88720134.

Resveratrol exerts a variety of biological and pharmacological activities, which are observed despite its extremely low bioavailability and rapid clearance from the circulation due to extensive sulfation and glucuronidation in the intestine and liver. In order to more accurately quantify all known resveratrol metabolites, a sensitive and optimized analytical assay was developed and validated by pure standards. Methodology improvements aimed to the chromatographic detection of disulfates and sulfoglucuronides, improving resolution of sulfates, by using a buffered solution, with recovery values of resveratrol and its metabolites, even of sulfates, of 99%. The adapted methodology was then applied to a clinical study with high cardiovascular risk subjects, after the moderate consumption of red wine (RW) or dealcoholized red wine (DRW) for 28 days. Up to 21 resveratrol metabolites, including those formed by gut and microbial metabolism, were identified in 24-h urine samples. Interestingly, after long-term consumption of RW and DRW, resveratrol metabolite concentration significantly increased in urine with no differences between the two interventions, indicating that bioavailability and biotransformation of resveratrol is not affected by the alcoholic matrix of wine. In summary, we established a sensitive analytical assay for the quantification of a wide resveratrol metabolic profile in human urine, also regarding gut microbial-derived metabolites, which may also be applied to blood and tissue samples. The resveratrol metabolic pattern might therefore act as an excellent marker for the efficacy of resveratrol in clinical and epidemiological studies for the study of the beneficial effects of grape product consumption. In this sense, having a more precise concentration value of all the resveratrol metabolites in target tissues would finally lead to a better interpretation of the obtained results., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Phenol-Explorer, launched in 2009, is the only comprehensive web-based database on the content in foods of polyphenols, a major class of food bioactives that receive considerable attention due to their role in the prevention of diseases. Polyphenols are rarely absorbed and excreted in their ingested forms, but extensively metabolized in the body, and until now, no database has allowed the recall of identities and concentrations of polyphenol metabolites in biofluids after the consumption of polyphenol-rich sources. Knowledge of these metabolites is essential in the planning of experiments whose aim is to elucidate the effects of polyphenols on health. Release 2.0 is the first major update of the database, allowing the rapid retrieval of data on the biotransformations and pharmacokinetics of dietary polyphenols. Data on 375 polyphenol metabolites identified in urine and plasma were collected from 236 peer-reviewed publications on polyphenol metabolism in humans and experimental animals and added to the database by means of an extended relational design. Pharmacokinetic parameters have been collected and can be retrieved in both tabular and graphical form. The web interface has been enhanced and now allows the filtering of information according to various criteria. Phenol-Explorer 2.0, which will be periodically updated, should prove to be an even more useful and capable resource for polyphenol scientists because bioactivities and health effects of polyphenols are dependent on the nature and concentrations of metabolites reaching the target tissues. The Phenol-Explorer database is publicly available and can be found online at http://www.phenol-explorer.eu. Database URL: http://www.phenol-explorer.eu.