Absorption Characteristics and Mechanism of P-glycoprotein Mediated Transport of Oleanolic Acidin Across the Membrane In Vitro / 医药导报

ABSTRACT

Objective To explore the absorption characteristics and mechanism of P-glycoprotein (P-gp) mediated transport of oleanolicacid (OA)across membrane in vitro.Methods The intake and transport of OA were evaluated by an HPLC/MS quantitative detection method.Safe concentration range of OA was determined by MTT.The effect of different drug concentration,incubation time,pH and temperature on the intake of OA by Caco-2 cells were investigated.The effect of P-gp inhibitor on the transmembrane transport of OA was investigated by the Caco-2 cell monolayer model,and the apparent permeability coefficient (Papp) was calculated.Results The uptake of O A was concentration-time dependent and correlated negatively to temperaturein Caco-2 cells within the safe concentration range,but was not significantly affected by pH value.Compared with controls,the Papp significantly changed when the P-gp inhibitor was added to the model(P ＜ 0.05).The apparent permeability ratio decreased from 2.90 to 0.95.Conclusion The absorption of OA was primarily by passive diffusion and might be mediated by the effiux by P-gp.