In vitro evaluation of intestinal absorption of tiliroside from Edgeworthia gardneri (Wall.) Meisn.

Abstract

Although Edgeworthia gardneri (Wall.) Meisn and its main component tiliroside (TIL) show good bioactivity, its intestinal absorption data supporting its low bioavailability have not been reported. The evaluation results of three absorption models in vitro and in vivo indicated that the results of the Ussing chamber model were basically consistent with the results of in vivo experiments. It was thus applied to investigate the characteristics of TIL across various intestinal regions and the interaction between TIL and adenosine triphosphate (ATP)-binding cassette family proteins (ABC) including, P-glycoprotein (P-gp), multidrug resistance-associated protein 2 (MRP2), and breast cancer resistance protein (BCRP). The data of the bi-directional transport showed that the ileum had the higher apparent permeability coefficient (Papp ) of TIL than duodenum and jejunum, suggesting the best absorption of TIL in the ileum. In the presence of the MRP2 inhibitor, the absorption of TIL from water extracts of E. gardneri (Wall.) Meisn (WAE) was improved, indicating that MRP2 other than P-gp and BCRP affected the absorption of TIL and might be responsible for its low bioavailability. This study laid the foundation for enhancing the bioavailability of TIL and highlighted the influences of efflux transporters on bioavailability.