In vitro assessment of cytochrome P450 2C19 potential of Naoxintong

Abstract

The effects of Buchang Naoxintong Capsules (BNCs) on S-mephenytoin 4′-hydroxylation activities in human liver microsomes in vitro were assessed. Human liver microsome was prepared by different ultracentrifugation. Human liver microsome incubation experiment was carried out to assay BNC on S-mephenytoin 4′-hydroxylation activities. The 4′-hydroxylation of S-mephenytoin, a representative substrate toward CYP2C19, was increased by phenytoin sodium (positive control). After the incubation, the metabolites of the substrates (4′-OH-mephenytoin) were determined by HPLC. Results showed that both phenytoin sodium and BNC showed obvious increase effect on CYP2C19. The enzymatic reaction of BNC was observed with concentrations ranging from 5μg/mL to 250μg/mL. Compared to blank, the increase effect of BNC showed significant difference from the beginning of concentration of 150μg/mL (P<0.001). The conclusion was that BNC showed obvious increase effect on the catalytic activities of drug-metabolising CYP2C19 enzyme. Copyright 2012 Hui Chen et al.