Related Experiment Video
Updated: Jun 25, 2026

Formation of Covalent DNA Adducts by Enzymatically Activated Carcinogens and Drugs In Vitro and Their Determination by 32P-postlabeling
Published on: March 20, 2018
Characterization of human cytochrome P450 enzymes involved in the biotransformation of eperisone
1Korea Institute of Science and Technology (KIST), Doping Control Center, Seoul, Korea. behappy@kist.re.kr
Abstract:
Eperisone is a centrally acting muscle relaxant widely used for the therapeutic treatment of spastic patients to relieve muscle stiffness and back pain. The objective of this study was to characterize the metabolic pathway involved in the biotransformation of eperisone mediated by human cytochrome P450 (CYP) enzymes. Eperisone was metabolized to seven metabolites via oxidation and carbonyl reduction in human liver microsome. Among them, M3 and M4 were found to be primary major metabolites which were generated by CYPs. The kinetics study with (-)-R- and (+)-S-eperisones revealed that CYPs-mediated hydroxylation did not have significant stereoselectivity for metabolic clearance of eperisone. Incubation with recombinant CYP isozyme, chemical inhibition assay, and immuno-inhibition assay showed that multiple CYPs were involved in M4 formation, but mainly CYP2J2 in M3 formation. In addition, intestinal microsomes metabolized eperisone to M3 and M4 via CYP2J2- and CYP3A4-mediated reactions, which are supposed to contribute to presystemic metabolism of eperisone.
Related Concept Videos
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
Drug Metabolism: Phase I Reactions
Drug Biotransformation: Overview
Drug Biotransformation: Overview
Phase I Reactions: Oxidation of Aliphatic and Aromatic Carbon-Containing Systems
Oxidation reactions are fundamental in aromatic carbon-containing systems. An example is the hydroxylation of phenobarbital, a process that transforms it into...
Factors Affecting Drug Biotransformation: Biological
Species differences: Variations in enzyme systems across species can cause disparities in drug metabolism. For instance, humans may metabolize certain drugs faster than rodents, altering therapeutic effects.
Strain differences: Genetic variations within a species can result in differing enzyme activity, impacting drug response and toxicity. For example, some mouse strains may...
