Related Experiment Video
Updated: Apr 13, 2026

Mass Spectrometry and Luminogenic-based Approaches to Characterize Phase I Metabolic Competency of In Vitro Cell Cultures
Published on: March 28, 2017
In vitro inhibition of human cytochrome P450 by cudratricusxanthone A
Juhee Sim1, Eunhwa Choi2, You-Mie Lee1
1College of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University, Republic of Korea.
Abstract:
Cudratricusxanthone A (CTXA) isolated from the roots of Cudrania tricuspidata Bureau (Moraceae) has several biological activities, including hepatoprotective, neuroprotective, anti-inflammatory, monoamine oxidase inhibitory, and antithrombotic activities. In this study, we investigated the potential herb-drug interaction of CTXA and nine cytochrome P450 (CYP) isoforms in pooled human liver microsomes (HLMs) using a cocktail probe assay. CTXA reversibly inhibited the CYP1A2-catalyzed phenacetin O-deethylation, CYP2C8-catalyzed paclitaxel 6-hydroxylation, and CYP2C9-catalyzed diclofenac 4'-hydroxylation with half-maximal inhibitory concentration (IC50) values of 3.9, 4.7, and 2.9 µM, respectively. The IC50 values did not change under different preincubation conditions. CTXA showed marked dose-dependent, but not time-dependent, inhibition of CYP1A2 and 2C9 activities in HLMs. Dixon plots showed typical competitive inhibition of CYP1A2 and CYP2C9 with Ki values of 1.3 and 1.5 µM, respectively. Further, CTXA inhibited CYP2C8 in a non-competitive manner with a Ki value of 2.2 µM. Our results showed that CTXA reversibly inhibits CYP1A2, 2C8, and 2C9.
More Related Videos
14:57Spectrophotometric Screening for Potential Inhibitors of Cytosolic Glutathione S-Transferases
Published on: October 10, 2020
10:25Screening Traditional Chinese Medicine Compounds for Inhibiting UCHL3 Activity Based on Molecular Docking and Deubiquitinating Enzyme Probe Technology
Published on: November 22, 2024
Related Concept Videos
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
The Electron Transport Chain
Inhibitors of the electron transport chain
Rotenone, a widely used pesticide, prevents electron transfer from Fe-S cluster to ubiquinone or Q...
Inhibition of Cdk Activity
Inhibition of CDK Activity
Enzyme Inhibition
Pharmacokinetics: Drug–Drug Interactions