title: Effect of myricetin on cytochrome P450 isoforms CYP1A2, CYP2C9 and CYP3A4 in rats.
abstract: Myricetin is one of the main ingredients of Chinese bayberry, which is used as a traditional medicine. The purpose of this study was to find out whether myricetin influences the rat cytochrome P450 (CYP) enzymes (CYP1A2, CYP2C9 and CYP3A4) by using cocktail probe drugs in vivo. A cocktail solution at a dose of 5 mL/kg, which contained phenacetin (20 mg/kg), tolbutamide (5 mg/kg) and midazolam (10 mg/kg), was orally administered to rats treated for 14 days with myricetin. Blood samples were collected at a series of time-points and the concentrations of probe drugs in plasma were determined by HPLC-MS/MS. The corresponding pharmacokinetic parameters were calculated by the software of DAS 2.0. Our study showed that treatment with multiple doses of myricetin had no effects on rat CYP1A2. However, CYP2C9 and CYP3A4 enzyme activities were inhibited after multiple doses of myricetin. Therefore, caution is needed when myricetin is co-administered with CYP2C9 or CYP3A4 substrates, which may result in herb-drug interactions.
authors.forename: Yu-Jin
authors.initials: YJ
authors.lastname: Guo
authors.forename: Shuang-Li
authors.initials: SL
authors.lastname: Zheng
mesh_terms: D000818:Animals; D019540:Area Under Curve; D019388:Cytochrome P-450 CYP1A2 / Q000378:metabolism*; D051544:Cytochrome P-450 CYP3A / Q000378:metabolism*; D065692:Cytochrome P-450 CYP3A Inhibitors; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004791:Enzyme Inhibitors; D005419:Flavonoids / Q000494:pharmacology*; D006207:Half-Life; D007202:Indicators and Reagents; D008297:Male; D008874:Midazolam / Q000493:pharmacokinetics; D010615:Phenacetin / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D014044:Tolbutamide / Q000493:pharmacokinetics
chemical_list: D065692:Cytochrome P-450 CYP3A Inhibitors; D065607:Cytochrome P-450 Enzyme Inhibitors; D004791:Enzyme Inhibitors; D005419:Flavonoids; D007202:Indicators and Reagents; C040015:myricetin; D003577:Cytochrome P-450 Enzyme System; D014044:Tolbutamide; C507848:CYP2C9 protein, rat; C465260:Cyp3a2 protein, rat; D019388:Cytochrome P-450 CYP1A2; D051544:Cytochrome P-450 CYP3A; D010615:Phenacetin; D008874:Midazolam