Transport and metabolic profiling studies of amentoflavone in Caco-2 cells by UHPLC-ESI-MS/MS and UHPLC-ESI-Q-TOF-MS/MS.

Amentoflavone, a kind of biflavonoid existing in several medicinal plants such as Selaginella moellendorfi and Gingko biloba, possesses anti-inflammatory, antioxidant, anti-virus, anti-tumor activities. In the present study, a new reliable and sensitive UHPLC-ESI-MS/MS method was developed to determine the permeability of amentoflavone under different conditions, and its metabolites in Caco-2 cells were identified by means of UHPLC-Q-TOF-MS/MS method. The results showed that amentoflavone could be considered as a compound with moderate intestinal absorption in Caco-2 cell model and its absorption characteristics might be involved in paracellular passive penetration and clathrin-mediated endocytosis with no participation of efflux transporters. Eight metabolites of amentoflavone were identified in Caco-2 cell model, indicating that the main metabolic pathways were oxidation, reduction, methylation and glucuronide conjugation. This study can provide valuable evidence for an in-depth understanding of absorption mechanism and transformation of amentoflavone in the intestine.