齐墩果酸体外肠吸收特征及P-糖蛋白介导跨膜转运机制

摘要

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.%目的 观察齐墩果酸体外肠吸收特征及P-糖蛋白介导跨膜转运的机制.方法 建立齐墩果酸细胞摄取量以及转运量高效液相色谱-质谱联用仪的定量检测方法,噻唑蓝法确定齐墩果酸对Caco-2细胞的安全浓度范围,考察不同药物浓度、孵育时间、介质pH值、体系温度对Caco-2细胞摄取齐墩果酸的影响;通过构建Caco-2细胞单层模型,评价P-糖蛋白抑制药维拉帕米对齐墩果酸跨膜转运的影响,计算其表现渗透系数(Papp).结果 在安全浓度范围内,Caco-2细胞对齐墩果酸摄取量呈浓度和时间依赖性,与温度呈负相关,不同pH值对药物摄取影响差异无统计学意义.与对照组比较,加入维拉帕米后,Papp显著改变(P＜0.05),表现渗透率由2.90下降至0.95.结论 齐墩果酸吸收转运以被动扩散为主,可能有P-糖蛋白介导外排作用的参与.