title: In vitro evidence of baicalein's inhibition of the metabolism of zidovudine (AZT).
abstract: BACKGROUND
  Herb-drug interaction (HDI) has been regarded as a key factor limiting the clinical application of herbs and drugs.
  
  
  OBJECTIVE
  Potential baicalein-zidovudine (AZT) interaction was predicted in the present study.
  
  
  METHODS
  In vitro evaluation of baicalein's inhibition towards human liver microsomes (HLMs)-catalyzed metabolism of zidovudine (AZT) was performed. Dixon and Lineweaver-Burk plots were used to determine the inhibition kinetic type, and second plot with the slopes from Lineweaver-Burk plot versus the concentrations of baicalein was employed to calculate the inhibition parameter (Ki). In combination with the in vivo concentration of baicalein, in vitro-in vivo extrapolation (IVIVE) was carried out to predict in vivo baicalein-AZT interaction.
  
  
  RESULTS
  Competitive inhibition of baicalein towards AZT metabolism was demonstrated, and the Ki value was calculated to be 101.2 µM. The value of AUCi/AUC was calculated to be 2.
  
  
  CONCLUSIONS
  Potential baicalein-AZT interaction was indicated in the present study, indicating the need for monitoring when AZT is co-administrated with baicalein or baicalein-containing herbs.
authors.affiliation: Yantaishan hospital, Yantai, Shandong, China.
authors.forename: Yu-Cun
authors.initials: YC
authors.lastname: Wang
authors.affiliation: Yantaishan hospital, Yantai, Shandong, China.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Yang
authors.affiliation: Yantaishan hospital, Yantai, Shandong, China.
authors.forename: Ling-Ting
authors.initials: LT
authors.lastname: Kong
authors.affiliation: Yantaishan hospital, Yantai, Shandong, China.
authors.forename: Feng-Xia
authors.initials: FX
authors.lastname: Yu
mesh_terms: D019380:Anti-HIV Agents / Q000378:metabolism*; D019540:Area Under Curve; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D044950:Flavanones / Q000493:pharmacokinetics* / Q000494:pharmacology; D041743:Herb-Drug Interactions; D006801:Humans; D066298:In Vitro Techniques; D008862:Microsomes, Liver / Q000378:metabolism*; D011237:Predictive Value of Tests; D018894:Reverse Transcriptase Inhibitors; D015215:Zidovudine / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D019380:Anti-HIV Agents; D004791:Enzyme Inhibitors; D044950:Flavanones; D018894:Reverse Transcriptase Inhibitors; C006680:baicalein; D015215:Zidovudine
keywords: Baicalein; herb-drug interaction; metabolism; zidovudine (AZT)