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Evidence-Based Complementary and Alternative Medicine
Volume 2013, Article ID 179643, 10 pages
Research Article

Inhibitory Effects of Baicalin on the Expression and Activity of CYP3A Induce the Pharmacokinetic Changes of Midazolam in Rats

Department of Clinical Pharmacology, School of Medicine, Zhengzhou University, Daxue Road 40, Zhengzhou, Henan 450052, China

Received 13 December 2012; Revised 24 February 2013; Accepted 3 April 2013

Academic Editor: Kanokwan Jarukamjorn

Copyright © 2013 Xin Tian et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Baicalin, a flavonoid compound isolated from Scutellaria baicalensis, has been shown to possess antiinflammatory, antiviral, antitumour, and immune regulatory properties. The present study evaluated the potential herb-drug interaction between baicalin and midazolam in rats. Coadministration of a single dose of baicalin (0.225, 0.45, and 0.90 g/kg, i.v.) with midazolam (10 mg/kg, i.v.) in rats resulted in a dose-dependent decrease in clearance (CL) from 25%   to 34%   with an increase in from 47%   to 53%   . Pretreatment of baicalin (0.90 g/kg, i.v., once daily for 7 days) also reduced midazolam CL by 43%   , with an increase in by 87%   . Multiple doses of baicalin decreased the expression of hepatic CYP3A2 by approximately 58%   and reduced midazolam 1′-hydroxylation by 23%   and 4′-hydroxylation by 21%   in the liver. In addition, baicalin competitively inhibited midazolam metabolism in rat liver microsomes in a concentration-dependent manner. Our data demonstrated that baicalin induced changes in the pharmacokinetics of midazolam in rats, which might be due to its inhibition of the hydroxylation activity and expression of CYP3A in the liver.