TY - JOUR T1 - Effects of Short-Term and Long-Term Pretreatment of <em>Schisandra</em> Lignans on Regulating Hepatic and Intestinal CYP3A in Rats JF - Drug Metabolism and Disposition JO - Drug Metab Dispos SP - 2399 LP - 2407 DO - 10.1124/dmd.109.027433 VL - 37 IS - 12 AU - Li Lai AU - Haiping Hao AU - Qiong Wang AU - Chaonao Zheng AU - Fang Zhou AU - Yitong Liu AU - Yuxin Wang AU - Guo Yu AU - An Kang AU - Ying Peng AU - Guangji Wang AU - Xijing Chen Y1 - 2009/12/01 UR - http://dmd.aspetjournals.org/content/37/12/2399.abstract N2 - This study aimed to evaluate the effects of Schisandra lignan extract (SLE) with short- and long-term pretreatment on regulating rat hepatic and intestinal CYP3A for a comprehensive evaluation of metabolism-based herb-drug interactions. Inhibitory effects of SLE and its major components on rat CYP3A were confirmed in both hepatic and intestinal microsomal incubation systems. After a single dose of SLE pretreatment, higher Cmax and area under the concentration-time curves from zero to infinity (AUC0-∞) values were observed for intragastric midazolam (MDZ), whereas those for the intravenous MDZ were little changed. The mechanism-based inhibition of SLE toward CYP3A was further confirmed in vivo, characterized with a recovery half-life of 38 h. In contrast, SLE long-term treatment enhanced both hepatic (2.5-fold) and intestinal (4.0-fold) CYP3A protein expression and promoted the in vivo clearance of MDZ. When MDZ was coadministered with SLE after a consecutive long-term treatment, the AUC0-∞ value of MDZ was still lower than that of the control group, suggesting a much stronger inducing than inhibiting effect of SLE toward CYP3A. Furthermore, the intragastric administration of SLE exhibited a more intensive regulating effect toward intestinal than hepatic CYP3A, which could be partially explained by the relatively high exposures of lignans in the intestine. In conclusion, this study provides a comprehensive map for showing the complicated effects of SLE and its components on regulating rat CYP3A. The important findings are that SLE possesses a much stronger inducing than inhibiting effect on CYP3A, as well as a more intensive regulating effect on intestinal than hepatic CYP3A.Copyright © 2009 by The American Society for Pharmacology and Experimental Therapeutics ER -