Bioavailability, Absorption, and Metabolism of Pelargonidin-Based Anthocyanins Using Sprague–Dawley Rats and Caco-2 Cell Monolayers

The present study is aimed to clarify the absorption and metabolism properties of pelargonidin-based anthocyanins. Results showed that pelargonidin-3-O-rutinoside (Pg3R) was absorbed in its intact form after oral administration and reached a maximum plasma concentration of 175.38 ± 55.95 nM at 60 min. Three main metabolites were identified in plasma, including Pg3R-monoglucuronide (m/z 755.2046), Pg3R-hydroxylated (m/z 595.1644), and Pg3R-demethylated (m/z 565.1569) metabolites. The plasma concentration of the Pg3R-demethylated metabolite (57.04 ± 23.15 nM) was much higher than that of other two metabolites, indicating that demethylation was the main metabolic pathway for Pg3R, while the glucuronide conjugate was detected as the dominant metabolic form of pelargonidin-3-O-glucoside (Pg3G). The bioavailability of Pg3R (1.13%) was fourfold higher than that of Pg3G (0.28%), demonstrating that anthocyanins linked to the rutinoside may exhibit higher bioavailability than that of glucoside. In vitro transport study unveiled that passive diffusion and active efflux were involved in the absorption of Pg3R and Pg3G.