Abstract: In this paper, the effect of polyphenols extracted from Tieguanyin tea on the mRNA and protein expression levels of cytochromes P450 3a11 (Cyp3a11), 2d22 (Cyp2d22) and 2c37 (Cyp2c37) in the liver of mice was explored by real-time reverse transcription polymerase chain reaction（real-time RT-PCR） and Western blot. The results showedthat the polyphenol extract at low dose (150 mg/(kg·d)) significantly induced the mRNA expression of Cyp3a11, Cyp2d22, and Cyp2c37 (P < 0.05) in comparison with the control group, while it significantly induced the protein expression of Cyp2d22 but had no significant effect on the protein expression of Cyp3a11 and exhibited a significant inhibitory effect on the protein expression of Cyp2c37. The polyphenols at middle dose (300 mg/(kg·d)) significantly inhibited the mRNA and protein expression of Cyp3a11 and Cyp2c37 (P < 0.05) but had no significant effect the mRNA and protein expression of Cyp2d22. The polyphenols at high dose (600 mg/(kg·d)), although having no significant effect on the mRNA expression of three enzymes, significantly inhibited their protein expression levels (P < 0.05). Therefore, Tieguanyin tea polyphenols can affect both the mRNA and protein expression levels of Cyp3a11, Cyp2d22 and Cyp2c37 in the liver of mice, suggesting that metabolism-based interactions can occur when they are used in combination with medicines.

Key words: Teiguanyin tea, polyphenol extracts, Cyp450, mRNA, protein expression