Anthocyanin Glycosides from Berry Fruit Are Absorbed and Excreted Unmetabolized by Both Humans and Rats

Abstract

Anthocyanins, the red/blue pigments found in plants, are polyphenolic compounds consumed by humans and are part of a normal diet. Recent studies have shown that anthocyanins have substantial bioactivity including antioxidant activity and therefore may have beneficial effects on human health. Anthocyanins are a group of over 500 compounds of diverse structures containing different core phenolic aglycons and conjugated with sugars in a variety of glycosylation patterns. In this study, we have investigated the bioabsorption of 15 anthocyanins with structures containing different aglycons and conjugated sugars extracted from blueberry, boysenberry, black raspberry, and blackcurrant in both humans and rats. Intact and unmetabolized anthocyanins were detected in urine of rats and humans following dosing for all molecular structures investigated, thus demonstrating that anthocyanins with diverse molecular structure and from different dietary sources are bioavailable at diet relevant dosage rates. In addition, the relative concentrations of anthocyanins detected in urine following dosing varied, indicating that differences in bioavailability are due to variations in chemical structure. Our results suggest that the nature of the sugar conjugate and the phenolic aglycon are both important determinants of anthocyanin absorption and excretion in rats and humans.

Preliminary Studies on the Antinociceptive Activity of Vaccinium ashei Berry in Experimental Animal Models

“…In this context as been reported that polyphenols, including some anthocyanins, possess oral bioavailability in rodents 15,34,35 and that they are able to cross the rat bloodbrain barrier after red berry supplementation, 36,37 as well as after a single administration, suggesting that these compounds can feasibly have a direct effect on brain processes. Detection of anthocyanins in brain was very fast, less than 30 minutes.…”

Practical application of flavonoid-poor menu meals to the study of the bioavailability of bilberry anthocyanins in human subjects

“…McGhie and co-workers reported that consumed berry anthocyanins (189-439 mg of total anthocyanins) were excreted into the urine in an intact form in a human study. 21) In their study, participants were forbidden to consume fruit, vegetables, or tea during the experiment, although detailed information on the diet consumed was not described. The excretion percentages reported in their study were 0.029-0.064%, which is lower compared with our study, indicating the possibility that dietary habits, especially before and during the experiments, might affect the absorption and excretion of flavonoids such as anthocyanins.…”

Induction of a State of Iron Limitation in Uropathogenic Escherichia coli CFT073 by Cranberry-Derived Proanthocyanidins as Revealed by Microarray Analysis

“…Given that PACs induce a state of iron limitation in E. coli CFT073, it is possible that prevention of UTIs by cranberry PACs is partially the result of the extreme reduction in the amount of available iron to UPEC strains in the urinary tract. It is noteworthy that the absorption and metabolism of cranberry PACs by humans have not been thoroughly studied; however, reports from other laboratories have shown that proanthocyanidins and anthocyanins are mostly absorbed into the human circulatory system and transported into the urine in intact form (20,22,24). If further information about metabolites or induced compounds of PACs is published, research concerning the effects of these compounds on bacterial metab- olism must be conducted in order to obtain a thorough understanding of their potential as agents for the prevention of bacterial adhesion.…”