New insights into the bioavailability of red raspberry anthocyanins and ellagitannins

• Published in: Free radical biology & medicine Vol. 89; pp. 758 - 769
• Main Authors: Ludwig, Iziar A., Mena, Pedro, Calani, Luca, Borges, Gina, Pereira-Caro, Gema, Bresciani, Letizia, Del Rio, Daniele, Lean, Michael E.J., Crozier, Alan
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2015
• Subjects: Adult; Anthocyanins; Anthocyanins - pharmacokinetics; Bioavailability; Biological Availability; Chromatography, High Pressure Liquid; Ellagitannins; Female; Humans; Hydrolyzable Tannins - pharmacokinetics; In vivo metabolites; Male; Mass Spectrometry; Plasma; Raspberries; Rubus; Urine; Young Adult; Urine; Cmax; Plasma; In vivo metabolites; ADME; Raspberries; UHPLC-MS; Bioavailability; PDA; GIT; Ellagitannins; Tmax; Anthocyanins; ESI; CID
• ISSN: 0891-5849; 1873-4596
• DOI: 10.1016/j.freeradbiomed.2015.10.400

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. [Display omitted] •The bioavailability of raspberry anthocyanins and ellagitannins was studied.•There was a high, 15% recovery of anthocyanin metabolites in urine.•Ferulic acid metabolites derived from anthocyanins are absorbed in the proximal GIT.•Ellagitannins were converted phase II metabolites of urolithins in the distal GIT.•Highest levels of urolithin metabolites were detected in plasma 24h after intake.