Bioaccessibility and intestinal cell metabolism of xanthones in magosteen juice

Xanthones are a family of isoprenylated benzophenones present in mangosteen fruit. These compounds exhibit potent anti‐oxidant and anti‐inflammatory activities in vitro, but there is very limited information regarding their absorption to mediate such activities in vivo. We have examined the bioaccessibility of these compounds in mangosteen juice (Tahiti Trader®) containing pericarp using the coupled in vitro digestion/Caco‐2 human intestinal cell model. The juice contained 210mg α‐mangostin equivalents/ounce and 10 xanthones were identified with α‐magostin (75%), garcinone (10%), γ‐mangostin (7%) being most abundant. Xanthones were stable (99.5 ± 0.5% recovery) during simulated digestion of a meal containing juice, yogurt and 3% soybean oil. A mean of 30 ± 4.9% of xanthones partitioned in the filtered aqueous fraction during simulated digestion. Deletion of fat from the meal and absence of bile extract during digestion greatly transfer of xanthones to the aqueous fraction, suggesting that xanthones are largely delivered to intestinal epithelium in mixed micelles. The xanthones in the aqueous fraction of digesta were stable in cultures of differentiated Caco‐2 cells as 88% of initial amount was present after 4h incubation. Manosteen xanthones and their conjugated metabolites accounted for 53% and 47% of the total, respectively. Both glucuronidated and sulfated conjugates of all detected xanthones were present. These data suggest that xanthones in mangosteen are preferentially micellarized during digestion, transferred across the brush‐border surface of the enterocyte with similar efficiency as other dietary lipophilic compounds and (partially) metabolized by phase 2 enzymes. Supported by OARDC and Food Innovation Center.