title: New insights into the bioavailability of red raspberry anthocyanins and ellagitannins.
abstract: Red raspberries, containing ellagitannins and cyanidin-based anthocyanins, were fed to volunteers and metabolites appearing in plasma and urine were analysed by UHPLC-MS. Anthocyanins were not absorbed to any extent with sub nmol/L concentrations of cyanidin-3-O-glucoside and a cyanidin-O-glucuronide appearing transiently in plasma. Anthocyanins excreted in urine corresponded to 0.007% of intake. More substantial amounts of phase II metabolites of ferulic acid and isoferulic acid, along with 4'-hydroxyhippuric acid, potentially originating from pH-mediated degradation of cyanidin in the proximal gastrointestinal tract, appeared in urine and also plasma where peak concentrations were attained 1-1.5h after raspberry intake. Excretion of 18 anthocyanin-derived metabolites corresponded to 15.0% of intake, a figure substantially higher than obtained in other anthocyanin feeding studies. Ellagitannins pass from the small to the large intestine where the colonic microbiota mediate their conversion to urolithins A and B which appeared in plasma and were excreted almost exclusively as sulfate and glucuronide metabolites. The urolithin metabolites persisted in the circulatory system and were excreted in urine for much longer periods of time than the anthocyanin metabolites although their overall urinary recovery was lower at 7.0% of intake. It is events originating in the proximal and distal gastrointestinal tract, and subsequent phase II metabolism, that play an important role in the bioavailability of both anthocyanins and ellagitannins and it is their metabolites which appear in the circulatory system, that are key to elucidating the mode of action(s) underlying the protective effects of these compounds on human health.
authors.affiliation: Department of Food Technology, Universitat de Lleida, Lleida, Spain.
authors.forename: Iziar A
authors.initials: IA
authors.lastname: Ludwig
authors.affiliation: Department of Food Science, University of Parma, Parma, Italy.
authors.forename: Pedro
authors.initials: P
authors.lastname: Mena
authors.affiliation: Department of Food Science, University of Parma, Parma, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Calani
authors.affiliation: Department of Nutrition, University of California, Davis, CA, USA.
authors.forename: Gina
authors.initials: G
authors.lastname: Borges
authors.affiliation: Postharvest, Technology and Agrifood Industry Area, IFAPA, Córdoba, Spain.
authors.forename: Gema
authors.initials: G
authors.lastname: Pereira-Caro
authors.affiliation: Department of Food Science, University of Parma, Parma, Italy.
authors.forename: Letizia
authors.initials: L
authors.lastname: Bresciani
authors.affiliation: Department of Food Science, University of Parma, Parma, Italy; The Need for Nutrition Education/Innovation Programme, University of Cambridge, UK.
authors.forename: Daniele
authors.initials: D
authors.lastname: Del Rio
authors.affiliation: School of Medicine, University of Glasgow, Royal Infirmary, Glasgow, UK.
authors.forename: Michael E J
authors.initials: ME
authors.lastname: Lean
authors.affiliation: Department of Nutrition, University of California, Davis, CA, USA. Electronic address: alan.crozier44@gmail.com.
authors.forename: Alan
authors.initials: A
authors.lastname: Crozier
mesh_terms: D000328:Adult; D000872:Anthocyanins / Q000493:pharmacokinetics*; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D047348:Hydrolyzable Tannins / Q000493:pharmacokinetics*; D008297:Male; D013058:Mass Spectrometry; D065856:Rubus; D055815:Young Adult
chemical_list: D000872:Anthocyanins; D047348:Hydrolyzable Tannins
keywords: Anthocyanins; Bioavailability; Ellagitannins; In vivo metabolites; Plasma; Raspberries; Urine