title: Evaluation of Tetrahydropalmatine Enantiomers on the Activity of Five Cytochrome P450 Isozymes in Rats Using a Liquid Chromatography / Mass Spectrometric Method and a Cocktail Approach.
abstract: The aim was to evaluate the effects of tetrahydropalmatine (THP) enantiomers on the activity of five cytochrome P450 (CYP450) isozymes in vivo. A liquid chromatography / mass spectrometric (LC-MS) method was developed for simultaneous determination of five specific probe substrates including metoprolol (2D6), caffeine (1A2), dapsone (3A4), chlorzoxazone (2E1), and tolbutamide (2C9) in rat plasma. Analytes were separated with the mobile phase consisting of 0.1% acetic acid aqueous solution and acetonitrile in a gradient elution. The mass spectrometric detection via selected ion monitoring (SIM) was operated in both positive ion mode (for metoprolol m/z 268, caffeine m/z 195, and dapsone m/z 249) and negative ion mode (for chlorzoxazone m/z 168 and tolbutamide m/z 269) in the same run. Linear correlation was obtained (r(2)  > 0.99) over the concentration range of 0.050-25.0 µg/mL for caffeine and dapsone, 0.025-10.0 µg/mL for metoprolol, 0.050-50.0 µg/mL for chlorzoxazone, and 0.25-100.0 µg/mL for tolbutamide. Intra- and interday precision were less than 12.09%. The matrix effect ranged from 87.50% to 109.25% and the absolute recoveries were greater than 70%. The method was successfully applied to evaluate the effect of THP enantiomers on the activity of CYP450 isozymes by a cocktail approach. The pharmacokinetic results of five probe drugs indicated that there were stereoselective differences between the two THP enantiomers, i.e., d-THP had the potential to inhibit the activities of CYP2D6 and CYP1A2 isozymes, while l-THP inhibited CYP1A2 isozyme and induced CYP3A4 and CYP2C9 isozymes.
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai, China.
authors.forename: Wuhong
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Pharmacy, Eastern Hepatobiliary Surgery Hospital, Shanghai, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Shanghai Institute for Food and Drug Control, Shanghai, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Le
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai, China.|Department of Pharmacy, Eastern Hepatobiliary Surgery Hospital, Shanghai, China.
authors.forename: Yinying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai, China.|Shanghai Key Laboratory for Pharmaceutical Metabolite Research, Shanghai, China.
authors.forename: Yinli
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Pharmacy, Eastern Hepatobiliary Surgery Hospital, Shanghai, China.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Zhang
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai, China.|Shanghai Key Laboratory for Pharmaceutical Metabolite Research, Shanghai, China.
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Chai
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai, China.|Shanghai Key Laboratory for Pharmaceutical Metabolite Research, Shanghai, China.
authors.forename: Zhanying
authors.initials: Z
authors.lastname: Hong
mesh_terms: D000818:Animals; D001600:Berberine Alkaloids / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism*; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D001600:Berberine Alkaloids; D007527:Isoenzymes; C014215:tetrahydropalmatine; D003577:Cytochrome P-450 Enzyme System
keywords: cytochrome P450 isozymes; liquid chromatography mass spectrometry; probe drugs cocktail; rat plasma; tetrahydropalmatine enantiomers