Abstract: In this paper, we explored the effect of tea polyphenols from Huangshan Maofeng tea on the mRNA and protein expression levels of the drug-metabolizing enzyme Cyp3a11 and pregnane X receptor (PXR) by real-time reverse transcription polymerase chain reaction (real-time RT-PCR) and Western blot. We further used the transient co-transfection reporter gene assay to verify the role of PXR in regulating Cyp3a11 expression. The results showed that the tea polyphenols at doses of 75, 150 and 300 mg/(kg·d) could significantly induce the mRNA and protein expression of PXR and Cyp3a11. Reporter gene screening showed that the tea polyphenols at doses of 100, 200 and 300 μg/mL could significantly enhance cytochrome P4503A4 (CYP3A4) luciferase activity by (3.86 ± 0.05), (4.82 ± 0.72) and (5.38 ± 0.11) folds through the PXR pathway as compared to the solvent control group. Therefore, tea polyphenols from Huangshan Maofeng tea can significantly upregulate CYP3A4 expression via activating the PXR-CYP3A4 pathway.

Key words: Huangshan Maofeng tea, drug-metabolizing enzyme Cyp3a11, pregnane X receptor, mRNA, protein expression