Biomaterial Database

Inhibition of chlorzoxazone metabolism, a clinical probe for CYP2E1, by a single ingestion of watercress. 1998

I Leclercq, and J P Desager, and Y Horsmans

Gastroenterology Laboratory, Louvain Medical School, Brussels, Belgium.

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.

UI	MeSH Term	Description	Entries
D007538	Isoniazid	Antibacterial agent used primarily as a tuberculostatic. It remains the treatment of choice for tuberculosis.	Isonicotinic Acid Hydrazide,Ftivazide,Isonex,Isonicotinic Acid Vanillylidenehydrazide,Phthivazid,Phthivazide,Tubazide,Acid Vanillylidenehydrazide, Isonicotinic,Hydrazide, Isonicotinic Acid,Vanillylidenehydrazide, Isonicotinic Acid
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D009125	Muscle Relaxants, Central	A heterogeneous group of drugs used to produce muscle relaxation, excepting the neuromuscular blocking agents. They have their primary clinical and therapeutic uses in the treatment of muscle spasm and immobility associated with strains, sprains, and injuries of the back and, to a lesser degree, injuries to the neck. They have been used also for the treatment of a variety of clinical conditions that have in common only the presence of skeletal muscle hyperactivity, for example, the muscle spasms that can occur in MULTIPLE SCLEROSIS. (From Smith and Reynard, Textbook of Pharmacology, 1991, p358)	Centrally Acting Muscle Relaxants,Central Muscle Relaxants,Relaxants, Central Muscle
D012016	Reference Values	The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.	Normal Range,Normal Values,Reference Ranges,Normal Ranges,Normal Value,Range, Normal,Range, Reference,Ranges, Normal,Ranges, Reference,Reference Range,Reference Value,Value, Normal,Value, Reference,Values, Normal,Values, Reference
D002753	Chlorzoxazone	A centrally acting central muscle relaxant with sedative properties. It is claimed to inhibit muscle spasm by exerting an effect primarily at the level of the spinal cord and subcortical areas of the brain. (From Martindale, The Extra Pharmacopoea, 30th ed, p1202)	Paraflex,Parafon,Parafon Forte DSC
D004347	Drug Interactions	The action of a drug that may affect the activity, metabolism, or toxicity of another drug.	Drug Interaction,Interaction, Drug,Interactions, Drug
D004791	Enzyme Inhibitors	Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.	Enzyme Inhibitor,Inhibitor, Enzyme,Inhibitors, Enzyme
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man