Stereoselective metabolism of tetrahydropalmatine enantiomers in rat liver microsomes
Tetrahydropalmatine (THP), with one chiral center, is an active alkaloid ingredient in Rhizoma Corydalis. The aim of the present paper is to study whether THP enantiomers are metabolized stereoselectively in rat, mouse, dog, and monkey liver microsomes, and then, to elucidate which Cytochrome P450 (...
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Published in | Chirality (New York, N.Y.) Vol. 24; no. 5; pp. 368 - 373 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Chichester, UK
John Wiley & Sons, Ltd
01.05.2012
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Subjects | |
Online Access | Get full text |
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Summary: | Tetrahydropalmatine (THP), with one chiral center, is an active alkaloid ingredient in Rhizoma Corydalis. The aim of the present paper is to study whether THP enantiomers are metabolized stereoselectively in rat, mouse, dog, and monkey liver microsomes, and then, to elucidate which Cytochrome P450 (CYP) isoforms are predominately responsible for the stereoselective metabolism of THP enantiomers in rat liver microsomes (RLM). The results demonstrated that (+)‐THP was preferentially metabolized by liver microsomes from rats, mice, dogs, and monkeys, and the intrinsic clearance (Clint) ratios of (+)‐THP to (−)‐THP were 2.66, 2.85, 4.24, and 1.67, respectively. Compared with the metabolism in untreated RLM, the metabolism of (−)‐THP and (+)‐THP was significantly increased in dexamethasone (Dex)‐induced and β‐naphthoflavone (β‐NF)‐induced RLM; meanwhile, the Clint ratios of (+)‐THP to (−)‐THP in Dex‐induced and β‐NF‐induced RLM were 5.74 and 0.81, respectively. Ketoconazole had stronger inhibitory effect on (+)‐THP than (−)‐THP, whereas fluvoxamine had stronger effect on (−)‐THP in untreated and Dex‐induced or β‐NF‐induced RLM. The results suggested that THP enantiomers were predominately metabolized by CYP3A1/2 and CYP1A2 in RLM, and CYP3A1/2 preferred to metabolize (+)‐THP, whereas CYP1A2 preferred (−)‐THP. Chirality 24:368–373, 2012. © 2012 Wiley Periodicals, Inc. |
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Bibliography: | National Major Projects for Science and Technology Development of Ministry Science and Technology of China - No. 2009ZX09304-003 ark:/67375/WNG-CF4LT21F-1 Economic and Trade Commission of Zhejiang Province - No. N20100042 istex:7A8B9201C62F6B242779AB4D5255E614006CAB38 ArticleID:CHIR22020 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0899-0042 1520-636X |
DOI: | 10.1002/chir.22020 |