ABSTRACT
Objective: To study the absorption mechanism of dehydroandrographolide (DAL) in human Caco-2 cell monolayer model. Methods: Caco-2 cell monolayer model was applied to investigate the bidirectional transport of DAL. The effects of time, drug concentration, temperature, and P-gp inhibitor (Verapamil) on the absorption of DAL were observed. Drug concentration was measured by LC/MS/MS and the apparent permeability coefficients (Papp) were calculated. Results: With the time and concentration increasing, the bidirection transport of DAL in Caco-2 cell monolayer model was of time and concentration dependence, without saturation. And it was not influenced by the change of temperature and the presence of Verapamil. Conclusion: The absorption and transport of DAL are passive diffusion as the dominating process in Caco-2 cell monolayer model.