P-糖蛋白对番荔枝酰胺衍生物FLZ在Caco-2细胞模型中跨膜转运的影响

摘要

目的：考察转运蛋白P-糖蛋白（P-glycoprotein，P-gp）对番荔枝酰胺衍生物FLZ体外跨血脑屏障（Blood-brain barrier，BBB）转运的影响。方法采用体外培养的Caco-2细胞建立体外BBB模型，研究1,5,10μM FLZ跨膜转运特性。并探讨加入P-gp抑制剂5μM zosuquidar后FLZ跨膜转运的表观渗透系数和外排率的变化。结果FLZ在Caco-2细胞模型上显示出了极性转运特性，Papp（B~A）>Papp（A~B），并呈现出良好的剂量依赖关系。同时FLZ在Caco-2细胞的跨膜转运中也呈现外排现象，1,5,10μM FLZ的外排率ER值分别为2.56，3.67和5.06。P-gp抑制剂zosuquidar可以显著降低FLZ外排，增加转运。10μM FLZ的外排率由5.06降低为1.94，下降了2.6倍。结论FLZ具有P-gp的底物特性，P-gp参与了FLZ在BBB跨膜转运中的外排。%Objective To study the effect of P-glycoprotein (P-gp) on the transport characteristics of squamosamide derivative FLZ across in vitro blood-brain barrier (BBB) model. Methods A human intestinal epithelial cell Caco-2 in vitro BBB model was applied to study the transport characteristics of 1, 5, 10μM FLZ.The effects of P-gp inhibitor zosuquidar on the in vitro permeability and efflux ratio of FLZ were also investigated. Results The transport of various concentrations of FLZ (1, 5, 10 μM) through the Caco-2 model occurred in both A~B and B~A directions, and Papp B~A transport were significantly higher than those for A~B transport at each FLZ concentration. The efflux ratio of 1, 5, 10 μM FLZ was 2.56, 3.67 and 5.06, respectively, suggesting the presence of efflux pumps to remove FLZ from within cell membranes. Upon specific blocking of P-gp using zosuquidar increased intracellular accumulation of FLZ in Caco-2 model and significantly reduced the efflux ratio from 5.06 to 1.94. Conclusion FLZ is a substrate for the P-gp drug efflux transporter, and poor brain penetration of FLZ is mainly due to the P-gp transport system in the BBB.