Related Experiment Video
Updated: May 15, 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 inhibitory effect of luotonin A on human CYP1A
Yurngdong Jahng1, Oh Kwang Kwon, Sangkyu Lee
1College of Pharmacy, Yeungnam University, Gyeongsan 712-749, Korea.
Abstract:
Luotonin A, a pyrroloquinolinequinoline alkaloid, is a natural inhibitor of topoisomerase I. In the present study, cytochrome P450 (CYP) inhibition by luotonin A was examined in pooled human liver microsomes (HLMs) and human recombinant cDNA-expressed human CYPs using a cocktail probe assay to investigate potential drug-drug interactions. Luotonin A selectively inhibited CYP1A2-catalyzed phenacetin O-deethylation with an IC(50) of 6.3 μM in HLMs, and strongly decreased CYP1A2-catalyzed phenacetin O-deethylation dose-dependently in HLMs, but did not inhibit it time-dependently. Furthermore, the Lineweaver-Burk and secondary plots for the inhibition of CYP1A2 in HLMs well fitted competitive inhibition mode. Luotonin A showed the selectivity of inhibitory effects on CYP1A1 and CYP1A2 in human recombinant cDNA-expressed CYP 1A1 and 1A2, respectively. Luotonin A was found to be a potent CYP1A inhibitor that might cause drug-drug interactions when co-administrated with CYP1A substrates.
More Related Videos
06:14Optimized LC-MS/MS Method for the High-throughput Analysis of Clinical Samples of Ivacaftor, Its Major Metabolites, and Lumacaftor in Biological Fluids of Cystic Fibrosis Patients
Published on: October 15, 2017
06:14Estimating the Yield of Compounds on the TLC Plate via the Blue-LED Illumination Technique
Published on: October 6, 2022
Related Concept Videos
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
Enzyme Inhibition