Exploiting the phenol-explorer 2.0 database to analyze and characterize the polyphenol metabolome

Presenting author: J.A. Rothwell We gratefully acknowledge Danone Research, the French National Institute of Cancer and the University of Barcelona for financing the project.Phenol-Explorer is an open-access web database on polyphenols, a major group ofphytochemicals abundant in plant foods. Version 2.0 of the database was released in late 2011 andincludes comprehensive qualitative and quantitative data on the ‘polyphenol metabolome’ (i.e. allmetabolites derived from the over 500 polyphenols known in foods) in humans and experimentalanimals. Such databases are necessary for the screening of metabolomic profiles and theidentification of potential biomarkers of food consumption. The aim of this study was to analysethese new data to characterize and visualize the polyphenol metabolome. The update wasimplemented by the compilation of data on 383 polyphenol metabolites from 221 originalintervention studies. Research articles were first screened for suitability using pre-defined criteriaand then entered into a relational database via Microsoft Access. The polyphenol metabolome wasthen analyzed via a series of database queries and open-source visualization software. Data weremainly obtained in human and rat models, and profiles of metabolites were similar between thesespecies. The highest Cmax values (maximum plasma concentration) were found in rats, as higherdoses of pure polyphenols could be administered, although in both species, administration of purepolyphenols or polyphenol supplements led to much higher plasma concentrations thanadministration of foods. Conversely, Tmax (time to reach Cmax) was species-dependent and alwaysshorter in the rat. Additionally, the ensemble of all studies administering pure compounds to humansand animals allowed an insight into precursor-metabolite specificity. 5-O-Caffeoylquinic acid,catechin and epicatechin gave rise to the broadest range of metabolites, while hippuric, ferulic, 4-hydroxybenzoic, dihydrocaffeic and vanillic acids were the metabolites derived from the largestnumber of precursors. Knowledge of polyphenol metabolism is crucial to understanding their in vivobioactivities and the polyphenol metabolome is an important component of the information-richfood metabolome, which encompasses all metabolites derived from exposure to the diet.We gratefully acknowledge Danone Research, the French National Institute of Cancer and theUniversity of Barcelona for financing the project