芍药甘草汤对Caco-2细胞P-糖蛋白功能和表达的影响

目的:研究芍药甘草汤(SGT)对Caco-2细胞P-糖蛋白(P-gp)的功能和表达的影响。方法:采用Caco-2单层细胞模型,以P-gp底物3H-地高辛为探针,P-gp抑制剂维拉帕米(Ver)为阳性对照药,测定SGT对Caco-2细胞P-gp功能的影响;用免疫组化法检测SGT对Caco-2细胞膜上的P-gp表达的影响。结果:在Caco-2模型上,3H-地高辛从基底侧(BL)到肠腔侧(AP)与肠腔侧(AP)到基底侧(BL)的表观渗透系数(apparent permeabilities,Papp)比值Papp(BL→AP)/Papp(AP→BL)约为27倍,证明3H-地高辛在Caco-2模型上的吸收方式为主动吸收。阳性药Ver与3H-地高辛联合时,明显增高了3H-地高辛在AP→BL方向的Papp(BL→AP)达3.82倍,但对BL→AP方向的转运影响不明显,说明Ver可明显抑制P-gp活性。SGT在1/25 IC5,1/5IC5,IC5浓度范围对P-gp底物3H-地高辛从AP→BL方向的转运分别促进了159.83%,217.95%,160.26%。1/25 IC5,1/5 IC5浓度下对3H-地高辛在BL→AP方向的转运分别促进了59.16%,50.73%,而相对于IC5浓度下SGT对3H-地高辛在BL→AP方向的转运则无影响。免疫组化结果显示SGT对P-gp的表达有抑制作用。结论:SGT可抑制P-gp的功能和表达,从而促进P-gp底物的吸收。

Effect of Shaoyao Gancao Tang on function and expression of P-glycoprotein in Caco-2 cells

Objective: To investigate the effect of Shao Yao-Gan Cao-Tang on function and expression of P-glycoprotein(P-gp) in Caco-2 cells.Method: 3H-digoxin(Dig),a substrate of P-glycoprotein,was used as a probe to measure the P-gp-mediated drug efflux transport,which indicated the function of P-gp in Caco-2 cells,while Verapamil(Ver) was used as a positive P-gp inhibitor.P-gp expression in Caco-2 cells was tested by immunohistochemistry staining.Inhibition effect of SGT on P-gp-mediated drug efflux transport and P-gp expression were investigated.Result: Dig was shown a positive absorption mode in Caco-2 cell monolayer,characterized as the ratio of apparent permeabilities(Papp) from basolateral side to apical side Papp(BL→AP) and from apical side to basolateral side Papp(AP→BL) of Dig was 27.07.Addition of Ver into Dig transport media significantly inhibited P-gp activity which was indicated by increasing the Papp(AP→BL) of Dig by 3.82 times,whereas Ver had no significant effect on Papp(BL→AP).SGT(at the concentrations of 1/25 IC5,1/5 IC5,IC5) could promote Papp(AP→BL) of Dig by 159.83%,217.95%,160.26%.Papp(AP→BL) of Dig was mildly increased by 59.16%,50.73% by SGT at 1/25 IC5,1/5 IC5 respectively.Immunohistochemistry staining showed that SGT inhibited the expression of P-gp of Caco-2 cells.Conclusion: SGT showed the potential inhibition to the function and expression of P-gp,leading to the increase absorption of P-gp′s substrates.