Anthocyanin Metabolism in Rats and Their Distribution to Digestive Area, Kidney, and Brain

Abstract

Anthocyanins are present in human diet due to their wide occurrence in fruits and beverages. They possess antioxidant activities and could be involved in several health effects. The aim of this study was to investigate anthocyanin metabolism and distribution in the digestive area organs (stomach, jejunum and liver) and kidney, as well as a target tissue (brain) in rats fed with a blackberry (Rubus fruticosus L.) anthocyanin-enriched diet for 15 days. Identification and quantification of anthocyanin metabolites was carried out by HPLC-ESI-MS-MS and HPLC-DAD, respectively. The stomach exhibited only native blackberry anthocyanins (cyanidin 3-O-glucoside and cyanidin 3-O-pentose), while in other organs (jejunum, liver, and kidney) native and methylated anthocyanins as well as conjugated anthocyanidins (cyanidin and peonidin monoglucuronides) were identified. Proportions of anthocyanin derivatives differed according to the organ considered, with the liver presenting the highest proportion of methylated forms. Jejunum and plasma also contained aglycone forms. In the brain, total anthocyanin content (blackberry anthocyanins and peonidin 3-O-glucoside) reached 0.25 +/- 0.05 nmol/g of tissue (n = 6). The urinary excretion of total anthocyanins was low (0.19 +/- 0.02% of the ingested amount). Thus, organs of the digestive area indicated a metabolic pathway of anthocyanins with enzymatic conversions (methylation and/or glucurono-conjugation). Moreover, following consumption of an anthocyanin-rich diet, anthocyanins enter the brain.

Anthocyanin Cyanidin-3-Glucoside Attenuates Platelet Granule Release in Mice Fed High-Fat Diets

“…Furthermore, anthocyanins can be absorbed into the circulation in their intact form in small amounts, while substantial amounts of anthocyanins enter the colon and undergo extensive metabolic transformation by the gut microbiota, producing a wide range of aromatic and phenolic compounds (33). Several in vivo studies have shown that some of these compounds, such as protocatechuic acid (PCA), can be detected in the systemic circulation of rats and humans after consumption of the parent compounds (41). Notably, gut microbiota metabolites of anthocyanin may also contribute to the benefits of anthocyanin supplementation in vivo.…”

The interactions of flavonoids within neuronal signalling pathways

“…Furthermore, oral ingestion of pure epicatechin resulted in the detection of epicatechin glucuronide and 3 0 -O-methyl-epicatechin glucuronide in rat brain tissue [3]. Anthocyanidins have also been detected in the brain after oral administration [53,168], with several anthocyanidins being identified in different regions of rat brain after the animals were fed with blueberry [12]. Such flavonoid localisation has been correlated with increased cognitive performance, suggesting a central neuroprotective role of these components.…”

The neuroprotective potential of flavonoids: a multiplicity of effects

“…Their brain entry may also depend on their interactions with specific efflux transporters expressed in the BBB, such as P-glycoprotein [63] which appears to be responsible for the differences between naringenin and quercetin flux into the brain in situ [135]. In animals, flavanones have been found to enter the brain following their intravenous administration [79], whilst epigallocatechin gallate [115], epicatechin [3] and anthocyanins [26,116] Fig. 1 The structures of the main classes of flavonoids.…”