Objective: To study the absorption mechanism of icariin by using Caco-2 monolayer model.
Method: Caco-2 cell monolayer model was used to study the bi-direction transport of icariin. The effects of time, drug concentration and inhibitor on the absorption of icariin were studied. The concentration of icariin in cell culture medium was measured by UPLC and the apparent permeability coefficients (Papp) was calculated.
Result: The amount of icariin which was transported increased linearly with the time (14 hr). The ratio of PBA/PAB was larger than 4. Verapamil, the P-glycoprotein inhibitor, could cause significantly effect on transport of icariin, PAB increased, the ratio of PBA/PAB decreased.
Conclusion: The reason for low absorption of icariin in Caco-2 cell model may be the secretion of the P-gp transporter.