Phloridzin-sensitive transport of echinacoside and acteoside and altered intestinal absorption route after application of Cistanche tubulosa extract

Abstract

Objectives The objective of this study was to address the beneficial effects of Cistanche tubulosa extract on improving the low intestinal permeability of echinacoside (ECH) and acteoside (ACT). Methods Absorption of ECH and ACT in C. tubulosa extract was characterized using human intestinal Caco-2 cell monolayers with intact compounds. Glucose transporter-dependent absorption of ECH and ACT was confirmed by an in-situ intestinal perfusion technique. Key findings The apparent permeability (Papp) was not significantly different between intact ECH and intact ACT. In the presence of phloridzin, the Papp of the ECH and ACT at a high dose was reduced to 20% of the respective non-treatment, but was not altered by phloretin and verapamil. C. tubulosa extract at low and high doses enhanced the Papp of ECH and ACT (both by threefold), resulting in their large participation in sodium-dependent glucose transporter-independent absorption. At a low concentration, concomitant ECH and ACT levels in portal blood were significantly suppressed by phloridzin. Conclusion The dietary and medicinal C. tubulosa extract enhancing the intestinal absorption of ECH and ACT may serve to better manage human health, although the involvement of phloridzin-sensitive transport should be reduced.