【摘要】 目的研究川芎嗪和人参皂苷Rgl对Caco-2细胞上P-糖蛋白（P-gp）功能和表达的影响。方法利用高效液相色谱检测P-gp底物罗丹明-123的浓度,用流式细胞仪测定Caco-2细胞膜上P-gp的表达量。结果中、高浓度(120,240 mg·L^-1)的川芎嗪能够使Caco-2细胞内Rh-123的浓度分别增加了1.7和8.2倍,与细胞孵育72 h后能够使Caco-2细胞表面P-gp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和1.8倍。中浓度(10 mg·L^-1)的人参皂苷Rgl对罗丹明-123的外排和转运无显著影响。高浓度(20 mg·L^-1)的人参皂苷Rgl使细胞内Rh-123的浓度增加了3.5倍,使1.5 h后在BL侧累积转运量增加1.3倍。中、高浓度(10,20 mg·L^-1)的人参皂苷Rgl与细胞孵育72 h对P-gp的表达影响不大。中浓度(120 mg·L^-1)的川芎嗪和人参皂苷Rgl(10 mg·L^-1)合用时,细胞内Rh-123的浓度增加6.4倍,使罗丹明-123的累积转运量增加1.6倍,使P-gp的表达下调了38.2%。结论川芎嗪减少P-gp对细胞内罗丹明-123的外排,增强罗丹明-123跨小肠上皮细胞的转运;同时川芎嗪直接抑制P-gp的活性而影响P- gp功能,长期应用川芎嗪可下调P-gp的表达水平影响降低肠道P-gp的活性。高浓度的人参皂苷Rgl通过直接抑制P-gp的外排转运功能而影响肠道P-gp的功能,长期应用不影响P-gp的表达水平。当川芎嗪和人参皂苷Rgl合用时,对肠道P-gp功能具有协同抑制作用,但是对P-gp的表达无协同作用。更多还原

【Abstract】 OBJECTIVE To study the effect of tetramethylpyrazine and ginsenoside Rgl on the function and expression of p- glycoprotein in Caco-2 cells.METHODS HPLC-UV was used to detect the concentration of rhodamine-123,which was a substrate of p-glycoprotein.Flow cytometry was used to analyze the expression of p-glycoprotein in Caco-2 cell monolayers.RESULTS The cellular concentrations of rhodamine-123 were 1.7-fold and 8.2-fold as that of controls when being treated with tetramethylpyrazine at middle and high dose(120 and 240 mg·L^-1).The p-glycoprotein protein levels were down-regulated by 53.6% and 38.8% compare with the controls,when being incubated with tetramethylpyrazine for 72 h.The total quantity of rhodamine-123 in receiver chambers of transwell at 1.5 h were increased by 30% and 80%,compared with the controls.Ginsenoside Rgl in high dose(20 mg·L^-1) increased the cellular concentrations of rhodamine-123 to 3.5-fold as that of control,and was observed to increase the transport of rhodamine-by 30% and longer term（72 h） co-incubation of the Caco-2 cells with ginsenoside Rgl had no effect on the cellular p- glycoprotein protein levels.The cellular concentration of rhodamine-123 was 20.6-fold as that of the control when combining tetramethylpyrazine (120 mg·L^-1)with ginsenoside Rgl(10 mg·L^-1)in middle concentration.Longer term （72 h）co-incubation of the Caco-2 cells down-regulated the cellular p-glycoprotein protein levels by 61.8%,increased the total quantity of rhodamine-123 in receiver chambers at 1.5 h by 60%,compared with the control.CONCLUSION Tetramethylpyrazine is a substrate and inhibitor of p-glycoprotein,and it could significantly inhibit the function of p-glycoprotein,and seemed to act directly on the activity of p- glycoprotein or be a binding site competitor of rhodamine-123.Tetramethytpyrazine could significantly decrease the expression of p- glycoprotein after being incubated with Caco-2 cells in 72 h.Ginsenoside Rgl may be an inhibitor of p-glycoprotein.It could significantly inhibit the activity of p-glycoprotein at high concentration.Longer term （72 h） co-incubation of the Caco-2 cell monolayer with ginsenoside Rgl had no effect on p-glycoprotein levels.Ginsenoside Rgl inhibited the activity of p-glycoprotein without decreasing the expression of Caco-2 cell monolayer.Combining tetramethylpyrazine with ginsenoside Rgl showed a great synergistic effect on p- glyeoprotein mediated efflux and transport of rhodamine-123 in the cells but no synergistic effect on p-glyeoprotein’s expression.更多还原