edoc

Biomarkers of Flutamide-Bioactivation and Oxidative Stress In Vitro and In Vivo

Teppner, Marieke and Boess, Franziska and Ernst, Beat and Pähler, Axel. (2016) Biomarkers of Flutamide-Bioactivation and Oxidative Stress In Vitro and In Vivo. Drug Metabolism and Disposition, 44 (4). pp. 560-169.

Full text not available from this repository.

Official URL: http://edoc.unibas.ch/52927/

Downloads: Statistics Overview

Abstract

The nonsteroidal androgen-receptor antagonist flutamide is associated with hepatic injury. Oxidative stress and reactive metabolite formation are considered contributing factors to liver toxicity. Here we have used flutamide as a model drug to study the generation of reactive drug metabolites that undergo redox cycling to induce oxidative stress (OS) in vitro and in vivo. Lipid peroxidation (LPO) markers, as well as genes regulated by the redox-sensitive Nrf2 pathway, have been identified as surrogates for the characterization of OS. These markers and metabolism biomarkers for drug bioactivation have been investigated to characterize drug-induced hepatic damage. Rat hepatocytes and in vivo studies showed that several LPO markers, namely the isoprostanes 15R-PD2, dihydro keto PE2, and iPF(2α)-VI, as well as hydroxynonenal mercapturic acid metabolites, had increased significantly by 24 hours after flutamide treatment from 4.9 to 15.3-fold in hepatocytes and from 2.6 to 31.0-fold in rat plasma. Induction of mRNA expression levels for Nrf2-regulated genes was evident as well, with heme oxygenase 1, glutathione-S-transferase π1 and NAD(P)H dehydrogenase showing a 3.6-, 4.1-, and 1.9-fold increase in hepatocytes and 5.6-, 7.5-, and 94.1-fold in rat liver. All effects were observed at drug concentrations that did not show overt liver toxicity. Addition of an in situ hydrogen peroxide-generating system to in vitro experiments demonstrated the formation of a reactive di-imine intermediate as the responsible metabolic pathway for the generation of OS. The dataset suggests that hepatic oxidative stress conditions can be mediated via metabolic activation and can be monitored with suitable biomarkers preceding the terminal damage.
Faculties and Departments:05 Faculty of Science > Departement Pharmazeutische Wissenschaften > Pharmazie > Molekulare Pharmazie (Ernst)
UniBasel Contributors:Ernst, Beat
Item Type:Article, refereed
Article Subtype:Research Article
Publisher:American Society for Pharmacology and Experimental Therapeutics
ISSN:0090-9556
e-ISSN:1521-009X
Note:Publication type according to Uni Basel Research Database: Journal article
Identification Number:
Last Modified:28 Nov 2017 11:15
Deposited On:25 Oct 2017 13:25

Repository Staff Only: item control page