title: The significant inhibition on CYP3A caused by radix Aconiti single herb is not observed in the Wutou decoction: The necessity of combination therapy of radix Aconiti.
abstract: BACKGROUND
  Wutou (WT, Radix Aconiti), the mother root of Aconitum carmichaelii Debx., is a famous Chinese herb against rheumatoid arthritis. In Chinese clinics, PWT is often prepared as a decoction in combination with other herbs, such as Wutou decoction (WTD). The present study aimed to compare the effects of PWT single herb and WTD on CYP3A activity ex vivo and in vivo.
  
  
  METHODS
  In the ex vivo study, CYP3A activity was determined by using testosterone (Tes) as a specific probe. Levels of Tes and its metabolite 6β-hydroxytestosterone (6β-OH-Tes) were measured using a validated ultra-performance liquid chromatography (UPLC) method. CYP3A protein and mRNA levels were measured by using Western blot and real-time PCR, respectively. In the in vivo study, CYP3A activity was determined by using buspirone (BP) as a specific probe. The plasma concentrations of BP and its primary metabolites, namely, 1-(2-pyrimidinyl) piperazine (1-PP) and 6'-hydroxybuspirone (6'-OH-BP), were determined using a validated UPLC-tandem mass spectrometry (UPLC/MS/MS) method.
  
  
  RESULTS
  Compared with the control group, the formation rates of 6β-OH-Tes from Tes ex vivo significantly decreased in groups treated with PWT at the tested doses, and this decrease was accompanied by a striking decrease in CYP3A protein and mRNA levels. However, a significant increase was observed in the ratios in the WTD groups compared with PWT single herb groups. In vivo, both formation ratios of 6'-OH-BP and 1-PP from BP showed no significant change in the WTD group.
  
  
  CONCLUSIONS
  PWT can significantly inhibit CYP3A activity ex vivo at the tested doses because of the down-regulation of CYP3A protein and mRNA expression levels. WTD can significantly reverse the inhibition caused by PWT. WTD also had no significant effect on CYP3A activity in vivo. Results implied that the use of PWT as a part of the WTD prescription rather than PWT single herb is more appropriate in clinics.
authors.affiliation: International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006, PR China; Institute of Chinese Meteria Medica, China Academy of Chinese Medical Sciences, Beijing 100700, PR China.
authors.forename: Jinjun
authors.initials: J
authors.lastname: Wu
authors.affiliation: Institute of Chinese Meteria Medica, China Academy of Chinese Medical Sciences, Beijing 100700, PR China; College of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou 350108, PR China.
authors.forename: Zaixing
authors.initials: Z
authors.lastname: Cheng
authors.affiliation: College of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou 350108, PR China.
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
authors.affiliation: International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006, PR China.
authors.forename: Guiyu
authors.initials: G
authors.lastname: Zhang
authors.affiliation: International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006, PR China.
authors.forename: Shugui
authors.initials: S
authors.lastname: He
authors.affiliation: International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006, PR China.
authors.forename: Shuqiang
authors.initials: S
authors.lastname: Liu
authors.affiliation: International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006, PR China.
authors.forename: Zhufen
authors.initials: Z
authors.lastname: Lin
authors.affiliation: International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006, PR China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Zhu
authors.affiliation: International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006, PR China.
authors.forename: Zhongqiu
authors.initials: Z
authors.lastname: Liu
authors.affiliation: International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006, PR China; Institute of Chinese Meteria Medica, China Academy of Chinese Medical Sciences, Beijing 100700, PR China; College of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou 350108, PR China. Electronic address: linna888@163.com.
authors.forename: Na
authors.initials: N
authors.lastname: Lin
authors.affiliation: International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006, PR China. Electronic address: lllu@gzucm.edu.cn.
authors.forename: Linlin
authors.initials: L
authors.lastname: Lu
mesh_terms: D031841:Aconitum / Q000737:chemistry*; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D051544:Cytochrome P-450 CYP3A / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D065692:Cytochrome P-450 CYP3A Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D015536:Down-Regulation / Q000187:drug effects; D004338:Drug Combinations; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000494:pharmacology*; D008297:Male; D018517:Plant Roots; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D053719:Tandem Mass Spectrometry / Q000379:methods; D013739:Testosterone / Q000378:metabolism
chemical_list: D065692:Cytochrome P-450 CYP3A Inhibitors; D004338:Drug Combinations; D004365:Drugs, Chinese Herbal; D012333:RNA, Messenger; D013739:Testosterone; D051544:Cytochrome P-450 CYP3A
keywords: Buspirone; CYP3A; Drug–drug interactions; Processed Wutou; Testosterone; Wutou decoction