Intestinal Absorption Mechanism and the Effect of Cornus officinalis Sieb. et Zucc. on Sweroside in Vitro and in Vivo

Sweroside, a natural iridoid compound, is the main active component of Cornus officinalis Sieb. et Zucc. (CO), and has been used for the treatment of various diseases. This study investigated the intestinal absorption mechanism and the effect of CO on sweroside's absorption. The intestinal permeability of sweroside, was investigated using the human Caco-2 cell monolayer model. A pharmacokinetic study in rats was developed to investigate the effect of CO on sweroside's absorption in vivo. The intestinal absorption of sweroside occurred through passive diffusion with active diffusion, and sweroside might be coinposed of P-glycoprotein, multidrug resistance-associated protein and breast cancer resistance protein substrates. After CO was added, the absorption permeability from the apical (AP) to the basolateral (BL) side increased significantly by about 46.38%. Sweroside showed a higher systemic exposure after oral administration of CO than sweroside group rats. It can be assumed that some ingredients in CO promote sweroside's absorption.