Anthocyanin absorption, metabolism and distribution from a wild blueberry-enriched diet (Vaccinium angustifolium) is affected by diet duration in the Sprague-Dawley rat

The effect of wild blueberry consumption on anthocyanin (ACNs) distribution and metabolism in Sprague-Dawley (SD) rats was investigated. Thirty-two rats were fed for 4 or 8 weeks with a control (C) or a wild blueberry-enriched diet (8%) (WB). Anthocyanin profile in plasma, urine, feces, brain, and liver was evaluated by LC-MS/MS, and significantly increased in urine and not in feces after 8 weeks on the WB diet compared to that in 4 weeks, but no anthocyanins were detected in plasma, liver, and brain samples either in the C or WB groups. Metabolites of ACNs were detected in the plasma, urine, feces, and tissues of both the C and WB groups, but the urinary excretion of hippuric acid increased significantly after 4 and 8 weeks of WB consumption. Thus, it seems that ACNs are metabolized by the intestinal microflora to respective phenyl-alkyl acids, which can be further metabolized to benzoic acid. In conclusion, ACNs are bioavailable in rats, and the extent of their metabolism and excretion is based on diet duration. Additionally, urinary hippuric acid content could represent a potential biomarker of ACNs absorption and metabolism in the SD rat under the present experimental conditions.