Intestinal permeability of the constituents from the roots of Saposhnikovia divaricata in the human Caco-2 cell monolayer model.

The bidirectional intestinal permeability of the active constituents from the roots of Saposhnikovia divaricata, including four coumarins, anomalin (1), 5-methoxy-7-(3,3-dimethylallyloxy)coumarin (2), decursin (3), and decursinol angelate (4), as well as four chromones, cimifugin (5), prim-O-glucosylcimifugin (6), 3'- O-angeloylhamaudol (7), and sec-O-glucosylhamaudol (8), was studied by using the Caco-2 cell monolayer. These compounds were assayed by HPLC, and their transport parameters, including apparent permeability coefficients (P(app)), were then calculated. The bidirectional P(app) values of the compounds were compared with those of the markers, propranolol and atenolol. Compounds 1-5 and 7 were assigned to well-absorbed compounds, while 6 and 8 were assigned to moderately absorbed compounds. The transport of 1-7 increased linearly as a function of time up to 180 min and concentration within the test range of 10-200 µM, thus their passive diffusion mechanism was proposed. The results provided some useful information for predicting the intestinal absorption in vivo of these compounds.