白藜芦醇通过拮抗hPXR对P-gp的影响

Effect of resveratrol on expression and activity of P-gp through human pregnane X receptor pathway

目的研究白藜芦醇通过拮抗hPXR对P-gp基因(MDR1)、蛋白表达及活性的影响。方法在LS174T细胞中,采用瞬时共转染报告基因实验研究白藜芦醇对PXR介导的MDR1的转录调节作用,并进一步应用Real-Time定量PCR和Western blot方法检测白藜芦醇作用24 h后对利福平诱导的P-gp基因和蛋白变化的影响,罗丹明转运实验考察P-gp活性的变化。结果双荧光素酶报告基因检测结果显示,25和50μmol.L-1白藜芦醇可通过拮抗PXR将利福平对MDR1的诱导作用由4.70倍分别降至1.76倍和0.69倍(P<0.01),在过表达hPXR的LS174T细胞中,50μmol.L-1白藜芦醇可以将利福平诱导的MDR1 mRNA水平由1.8倍降至1.3倍(P<0.05),Western blot结果表明白藜芦醇也可降低利福平诱导的P-gp表达。此外,罗丹明转运实验显示,25和50μmol.L-1白藜芦醇可以将利福平抑制的累积量由77.7%升至91.7%和95.1%(P<0.05),表明白藜芦醇可降低利福平诱导的P-gp活性。结论白藜芦醇可以通过拮抗PXR而影响P-gp的基因、蛋白表达及活性。

Aim To investigate the effect of resveratrol on rifampicin-induced P-gp expression through PXR pathway.Methods Dual-Luciferase reporter assays were performed to detect the activity of MDR1 reporter gene in LS174T cells.Real-Time PCR and Western blot were used to detect mRNA and protein expression of P-gp.In addition,rhodamine 123（Rh123） accumulation assay was used to investigate the P-gp activity.Results Resveratrol（RES） could significantly down regulate the rifampicin-induced MDR1 reporter activation both in concentration of 25 and 50 μmol·L-1（P＆lt;0.01）.Besides,RES could also significantly down regulate rifampicin-induced P-gp mRNA expression only in hPXR-transfected cells,but P-gp protein expression was decreased both in hPXR-transfected and non-transfected cells.Furthermore,25 and 50 μmol·L-1 RES significantly increased rifampicin-inhibited Rh123 accumulation from 77.7% to 91.7% and 95.1%（P＆lt;0.05）,Which indicated that RES could reduce the induction of P-gp activity by rifampicin.Conclusion Resveratrol could affect P-gp expression and activity as an antagonist of human PXR.