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% (P < 0.05) to 34% (P < 0.001) with an increase in AUC0−∞ from 47% (P < 0.05) to 53% (P < 0.01). Pretreatment of baicalin www.cosmetics-add.com/Herb-Extracts/Baicalin/ (0.90 g/kg, i.v., once daily for 7 days) also reduced midazolam CL by 43% (P < 0.001), with an increase in AUC0−∞ by 87% (P < 0.01). Multiple doses of baicalin decreased the expression of hepatic CYP3A2 by approximately 58% (P < 0.01) and reduced midazolam 1′-hydroxylation by 23% (P < 0.001) and 4′-hydroxylation by 21% (P < 0.01) in the liver.
In addition, baicalin competitively inhibited midazolam metabolism in rat liver microsomes in a concentration-dependent manner.