title: Inhibition of chlorzoxazone metabolism, a clinical probe for CYP2E1, by a single ingestion of watercress.
abstract: To investigate the effect of watercress on the metabolism of chlorzoxazone, an in vivo probe for CYP2E1, the oral pharmacokinetics of chlorzoxazone was studied in 10 healthy volunteers before and after a single ingestion of a watercress homogenate (50 gm). A third chlorzoxazone pharmacokinetic study was performed after a 1-week treatment with isoniazid (300 mg/day), a well-known CYP2E1 inhibitor. Ingestion of watercress or isoniazid did not affect the oral absorption of chlorzoxazone. The area under the chlorzoxazone plasma concentration-time curve was significantly increased by 56% (p < 0.05) after watercress ingestion and by 135% (p < 0.001) with isoniazid treatment. Similarly, chlorzoxazone elimination half-life was prolonged after watercress (53%; p < 0.05) and isoniazid (104%; p < 0.01) administration. These results show that a single ingestion of watercress inhibits the hydroxylation of chlorzoxazone, an in vivo probe for CYP2E1.
authors.affiliation: Gastroenterology Laboratory, Louvain Medical School, Brussels, Belgium.
authors.forename: I
authors.initials: I
authors.lastname: Leclercq
authors.forename: J P
authors.initials: JP
authors.lastname: Desager
authors.forename: Y
authors.initials: Y
authors.lastname: Horsmans
mesh_terms: D000328:Adult; D000995:Antitubercular Agents / Q000097:blood / Q000494:pharmacology*; D002753:Chlorzoxazone / Q000097:blood / Q000493:pharmacokinetics*; D065691:Cytochrome P-450 CYP2E1 Inhibitors; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000097:blood / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007538:Isoniazid / Q000097:blood / Q000494:pharmacology*; D017879:Isothiocyanates / Q000097:blood / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009125:Muscle Relaxants, Central / Q000097:blood / Q000493:pharmacokinetics*; D012016:Reference Values
chemical_list: D000995:Antitubercular Agents; D065691:Cytochrome P-450 CYP2E1 Inhibitors; D004791:Enzyme Inhibitors; D017879:Isothiocyanates; D009125:Muscle Relaxants, Central; C058305:phenethyl isothiocyanate; D002753:Chlorzoxazone; D007538:Isoniazid