Generic placeholder image

Drug Metabolism Letters

Editor-in-Chief

ISSN (Print): 1872-3128
ISSN (Online): 1874-0758

Oxidative Bioactivation and Toxicity of Leflunomide in Immortalized Human Hepatocytes and Kinetics of the Non-Enzymatic to Its Major etabolitie, A77 1726

Author(s): Quee Ming Seah, Lee-Sun New, Eric C.Y. Chan and Urs A. Boeslsterli

Volume 2, Issue 3, 2008

Page: [153 - 157] Pages: 5

DOI: 10.2174/187231208785425791

Price: $65

Abstract

We used immortalized human hepatocytes to study the bioactivation of leflunomide and the metabolic degradation to its major metabolic,A77 1726. Both leflunomide and A77 1726 caused a time-and concentration-dependent increase in LDH release. The cytotoxicity of leflunomide,but not that of A77 1726, was prevented by the pan -CYP inhibitor, 1-aminobenzotriazole,indicating that an oxidative metabolite(s) was responsible for the cell injury.LC/MS/MS analysis revealed that leflunomide was rapidly degraded in hepatocytes biphasically(t1/2a=1.5 h,t1/2b > 24h),but much slower in cell-free medium(t1/2 > 24 h).In contrast,the generation of A77 1726 occured at a similar rate in cells and cell-free system s.In conclusion,leflunomide wsa rapidly metabolized in human hepatocytes to A77 1726, but its toxicity was dependent on other ,CYP-dependent intermedietly metabolized in human hepatocytes to A77 1726, but its toxicity was dependent on other ,CYP-dependent intermediidly metabolized in human hepatocytes to A77 1726, but its toxicity was dependent on other,CYP-dependent intermediidly metabolized in human hepatocytes to A77 1726,but its toxicity was dependent intermediates.

Keywords: Leflunomide, A77 1726, human hepatocytes, bioactivation, hepatotoxicity


Rights & Permissions Print Cite
© 2024 Bentham Science Publishers | Privacy Policy