摘要
目的:研究甘草酸18位差向异构体18α-甘草酸、18β-甘草酸对Caco-2细胞上P-糖蛋白功能和表达的影响。方法:建立Caco-2细胞模型,采用罗丹明-123摄取法评价P-糖蛋白的功能;利用流式细胞术和荧光定量PCR分析Caco-2细胞膜上P-糖蛋白的表达。结果:中、高浓度(10,60μmol.L-1)α-GL使细胞内Rho-123摄取增加,对P-gp表现出抑制作用,但没有呈现出剂量依赖性;β-GL各浓度组使细胞内Rho-123摄取减少,对P-gp表现出诱导作用,但也没有表现出剂量依赖性。二者对Caco-2细胞上P-gp功能的影响呈相反的趋势;Caco-2细胞与药物孵育72 h后,中、高浓度(10,60μmol.L-1)α-GL下调MDR1 mRNA表达,β-GL只在高浓度(60μmol.L-1)上调了MDR1 mRNA表达;高浓度(60μmol.L-1)β-GL在蛋白水平对P-gp有诱导作用,α-GL各浓度没有表现出对P-gp表达的影响。结论:转录水平上α-GL,β-GL对P-gp的影响与α-GL,β-GL对CYP3A的影响呈现一定的同向性,甘草酸18位差向异构体对CYP3A与P-gp的影响有相似的立体选择性,其机制是否与孕烷X受体(PXR)有关,有待进一步研究。
Objective: The aim of the present study was to evaluate the modulating effect of glycyrrhizic acid C-18 epimers,18α-glycyrrhizic acid(α-GL) and 18β-glycyrrhizic acid(β-GL) on both P-glycoprotein(P-gp) activity and expression in Caco-2 cell.Method: The effects of P-gp activity were analyzed by rhodamine(Rhd 123) accumulation test,and those of P-gp expression were analyzed by flow cytometry and real-time PCR.Result: At middle and high concentrations(10,60 μmol·L-1),α-GL inhibited the function of P-gp and with on dose dependent while β-GL induced the function of P-gp at three test concentrations with no dose dependent too.At middle and high concentrations(10,60 μmol·L-1),α-GL down-regulated the expression of MDR1 mRNA.At high concentrations(60 μmol·L-1),β-GL up-regulated the expression of MDR1 mRNA;At high concentrations(60 μmol·L-1),β-GL induced the expression of P-gp protein while α-GL has no effect on the expression of P-gp protein at three test concentrations.Conclusion: The effects of α-GL and β-GL on the expression of MDR1 mRNA and CYP3A mRNA showed the same trend.The character that epimers of GL act on CYP3A and P-gp show similar stereo selectivity whether relate to PXR need further study.
出处
《中国中药杂志》
CAS
CSCD
北大核心
2012年第1期99-103,共5页
China Journal of Chinese Materia Medica
基金
国家自然科学基金项目(30873114)
湖南省自然科学基金重点项目(11JJ2052)
湖南省中医药科研计划项目(2008086)
