Anthocyanins are absorbed in glycated forms in elderly women: a pharmacokinetic study

Background: Anthocyanins are potent antioxidants that are widely distribute d in fruit, vegetables, and red wines. Anthocyanin products are also prescr ibed as medicines in many countries for treating various diseases. However, the pharmacokinetics of dietary anthocyanins are not known in humans becau se these glycosides were long considered nonabsorbable. Objective: The objective of this study was to determine whether anthocyanin s can be absorbed as glycosides and to evaluate their pharmacokinetics in h umans. Design: Four healthy elderly women consumed 720 mg anthocyanins. A series o f blood and urine samples were collected before and after consumption of th e anthocyanins. Anthocyanins were measured in plasma and urine by combining an octadecylsilane solid-phase extraction for sample preparation and an HP LC system with diode array for anthocyanin separation and detection. The st ructures of anthocyanins as glycosides in plasma and urine were further con firmed by using liquid chromatography-mass spectrometry. Results: Anthocyanins were detected as glycosides in plasma and urine. The maximum plasma concentration of total anthocyanins varied from 55.3 to 168. 3 nmol/L, with an average of 97.3 nmol/L, and was reached within 71.3 min. The elimination of plasma anthocyanins appeared to follow first-order kinet ics. The elimination half-life of plasma total anthocyanins was calculated to be 132.6 min. Most anthocyanin compounds were excreted in urine during t he first 3 h. The excretion rate of total anthocyanins was 77 mug/h during the first 3 h and 13 mug/h during the second 4 h. Conclusion: Anthocyanins are absorbed in their unchanged glycated forms in elderly women.