川芎嗪对Caco-2细胞p-糖蛋白功能和表达的影响

目的研究川芎嗪对和Caco-2细胞p-糖蛋白功能和表达的影响。方法用p-糖蛋白底物罗丹明123在细胞外排和转运的改变指示细胞膜上p-糖蛋功能的改变,流式细胞仪分析Caco-2细胞膜上p-糖蛋白表达量的变化。结果中、高浓度(120、240μg.mL-1)的川芎嗪能够使罗丹明123从Caco-2细胞的外排量分别减少2.67倍和9.08倍,与细胞孵育72 h后能够使Caco-2细胞表面p-糖蛋白的表达水平下调46.4%和61.2%,在1.5 h使罗丹明123在Transwell的BL侧的累积排放量增加了1.3倍和1.8倍。结论川芎嗪可以显著减小罗丹明123在Caco-2细胞的外排,对罗丹明123跨细胞膜转运也有显著影响。将川芎嗪与Caco-2细胞共同培养72 h后,川芎嗪能够显著降低Caco-2细胞上p-糖蛋白的表达。川芎嗪与p-糖蛋白底物共同应用时要注意发生由p-糖蛋白介导的药物相互作用,川芎嗪可能是一种很有前途的多药耐药逆转剂。

Effects of tetramethylpyrazine on the function and expression of p-glycoprotein in Caco-2 cells

Objective To determine the effect of tetramethylpyrazine on both the p-glycoprotein expression and activity in Caco-2 cell monolayers.Methods We used a p-glycoprotein substrate,rhodamine 123,to indicate the function of p-glycoprotein,and flow cytometry was used to determine the expression of p-glycoprotein in Caco-2 cell monolayers.Results Middle and high dose of tetramethylpyrazine could decrease the efflux of rhodamine 123 from Caco-2 cells by 2.67 folds and 9.08 folds.Longer term(72 h) co-incubation of the Caco-2 cells with tetramethylpyrazine 53.6% and 38.8% down-regulated the cellular p-glycoprotein protein levels.Compared with the controls,the total quantity of rhodamine 123 in the receiver chambers of Transwell at 1.5 h were 1.3 and 1.8 folds higher than that of controls.Conclusion Tetramethylpyrazine may inhibit p-glycoprotein mediated efflux and transport of rhodamine123 in the cells.The acute inhibitory effect is dependent on the tetramethylpyrazine concentration.Longer term(72 h) co-incubation of the Caco-2 cells with tetramethylpyrazine decreased p-glycoprotein activity through the downregulation of the cellular p-glycoprotein protein levels.Attention should be paid to when tetramethylpyrazine is to be used together with p-glycoprotein substrates.