In Vivo Absorption and Tissue Distribution of Nanocapsulated Roselle Anthocyanins under Fasted and Fed States

This study investigated the absorption and tissue distribution of nanocapsulated roselle anthocyanin extract (Nano-RAE) in C57BL/6 mice under both fasted and fed conditions. Following gavage, Nano-RAE delayed the appearance of cyanidin-3-glucoside (C3G) and delphinidin-3-glucoside (D3G) in the liver, accompanied by enhanced metabolite formation and sustained concentration profiles consistent with controlled release. In contrast, unencapsulated roselle anthocyanin extract exhibited rapid tissue distribution, with higher brain levels of C3G and greater renal concentrations of pelargonidin-, petunidin-, and peonidin-3-glucoside. Additionally, Nano-RAE resulted in lower hepatic protocatechuic acid levels. Although anthocyanins were rapidly metabolized, intact C3G and D3G were detected in the brain, indicating penetration of the blood–brain barrier. Molecular docking revealed strong binding of C3G to mouse multidrug resistance protein 1a, suggesting an interaction that may affect its bioavailability and tissue distribution. These findings highlight the influence of encapsulation and feeding state on anthocyanin absorption and provide insights for designing dietary interventions.