Bioaccessibility, biotransformation, and transport of α-mangostin from Garcinia mangostana (Mangosteen) using simulated digestion and Caco-2 human intestinal cells

alpha- and gamma-Mangostin are the most abundant prenylated xanthones present in the fruit of the mangosteen tree. These compounds have been reported to possess numerous bioactivities that have provided the impetus for use of mangosteen products as nutraceuticals and in functional foods and dietary supplements. The health-promoting benefits of mangosteen are dependent on delivery of the xanthones to target tissues. Here, we used simulated digestion and Caco-2 cells to investigate the digestive stability, bioaccessibility, and intestinal cell transport of alpha- and gamma- mangostin. Recovery of alpha- and gamma-mangostin after simulated digestion of pericarp and fruit pulp exceeded 90%. Transfer of alpha- and gamma-mangostin to the aqueous fraction during simulated digestion was efficient (65-74%) and dependent on bile salts suggesting that micellarization is required for optimal bioaccessibility of xanthones. Cell uptake of xanthones from micelles was dose dependent and intracellular concentrations were maximum by 1 h. Both free and phase II metabolites of alpha-mangostin were transported in the basolateral compartment and metabolites also effluxed into the apical chamber. Transepithelial transport of alpha- mangostin was increased during prandial-like compared to fasted conditions suggesting that absorption is enhanced by dietary fat.