Upon characterization of baculovirus-expressed cytochrome P-450 (CYP) 2C19, it was observed that this enzyme metabolized (+/-) bufuralol to 1'hydroxybufuralol, a reaction previously understood to be selectively catalyzed by CYP2D6. The apparent K(m) for this reaction was 36 microM with recombinant CYP2C19, approximately 7-fold higher than for recombinant CYP2D6. The intrinsic clearance for this...

Objective(s): In this study, a cocktail of probe drugs was used to assess whether lentinan could influence the activities of rat enzymes CYP3A4, CYP2D6, CYP1A2, CYP2C19, and CYP2C9 in vivo. Materials and Methods: Fourteen days after intraperitoneal injection of lentinan, rats were given an oral dose of a cocktail solution containing phenacetin, tolbutamide, omeprazole, metoprolol, and midazolam...

CYP2C19 is a highly polymorphic gene and CYP2C19 enzyme results in broad inter-individual variability in response to certain clinical drugs, while little is known about the genetic variation of CYP2C19 in Li Chinese population. The aim of this study was to identify different CYP2C19 mutant alleles and determine their frequencies, along with genotype frequencies, in the Li Chinese population. We...

BACKGROUND Cytochrome P450 2C19 (CYP2C19) is an important drug-metabolizing enzyme (DME), which is responsible for the biotransformation of several kinds of drugs such as proton pump inhibitors, platelet aggregation inhibitors and antidepressants. Previous studies showed that Buchang NaoXinTong capsules (NXT) increased the CYP2C19 metabolic activity in vitro and enhanced the antiplatelet effect...

Conversion of clopidogrel (Plavix) to its active metabolite is catalyzed largely by the P450 enzyme 2C19 (CYP2C19). Numerous allelic variants of CYP2C19 exist. The *1 allele is considered wild type, whereas the *2 and *3 alleles have no in vivo enzymatic activity. Conversely, the *17 allele has increased expression, resulting in increased clopidogrel activation. Poor metabolizers (*2/*2 and *2/...

Although many cases of interindividual variation in the metabolism of CYP2C19 drugs are explained by the CYP2C19*2, *3, and *17, a wide range of metabolic variation still occurs in people who do not carry these genetic variants. The objectives of this study were to identify new genetic variants and to characterize functional consequences of these variants in metabolism of CYP2C19 substrates. In...

BACKGROUND CYP2C19 is known to be the main enzyme of biotransformation of proton pump inhibitors (PPIs), whereas the CYP2C19 gene is highly polymorphic. Genotyping and phenotyping together represent more reliable data about patient's CYP2C19 activity. PURPOSE The aim of the study was to investigate the applicability of urine metabolic ratio of omeprazole for CYP2C19 phenotyping in Russian pep...

BACKGROUND Previous studies accessing the association of CYP2C19 with outcomes of patients using tamoxifen for breast cancer have yielded conflicting results. The aim of this meta-analysis is to obtain a more precise estimate of effects of CYP2C19 polymorphisms and to clarify their effects on survival of the breast cancer patients using tamoxifen. MATERIALS AND METHODS A systematic search of ...

Lansoprazole is extensively metabolized by CYP2C19 and CYP3A4 in the liver, whereas rabeprazole is primarily converted non-enzymatically to rabeprazole-thioether, with only some being oxidized by CYP2C19 and CYP3A4. Lansoprazole and rabeprazole possess asymmetric sulfur in their chemical structure and have typically been used clinically as a racemic mixture. This article reviews the pharmacokin...