Abstract: To identify the effect on the rat hepatic CYP450 content after administer Glycyrrhiza uralensis Fisch and Schisandra chinensis Baill and to assay of substrates enzyme content an NADPH generating system consisting of imipramine metabolic in vivo was conducted. Rats were randomly divided into groups. The studied animals were allowed free access to water but the drug was given at morning blank abdomen. Two groups of rats received different dose of schisandra chinensis Baill or glycyrrhiza uralensis Fisch plant extracts once daily orally for three or six days. For rats in other groups received once dailly orally normal saline as blank control group and phenobarbital as positive control group at the same time The cytochrome P450 content of the groups of rats receiving schisandra chinensis Baill or glycyrrhiza uralensis Fisch plant extracts was enhanced; the pharmacokinetics of imipramine was changed. It is suggested that Glycyrrhiza uralensis Fisch and Schisandra chinensis Baill are inducer of the CYP450. The CYP450 content is relative with the time and dose of the traditional Chinese medcine. The metabolism of imipramine is quickened, and the pharmacokinetics of imipramine is changed.

Key words: glycyrrhiza uralensis Fisch, schisandra chinensis Baill, CYP450, imipramine