title: Induction of cytochrome P450 2B6 activity by the herbal medicine baicalin as measured by bupropion hydroxylation.
abstract: OBJECTIVE
  This study investigated the effect of the herbal medicine baicalin on bupropion hydroxylation, a probe reaction for CYP2B6 activity related to different CYP2B6 genotype groups.
  
  
  METHODS
  Seventeen healthy male volunteers (6 CYP2B6*1/*1, 6 CYP2B6*1/*6, and 5 CYP2B6*6/*6) received orally administered bupropion alone and during daily treatment with baicalin. Blood samples were taken up to 72 h after each bupropion dose, and pharmacokinetics profiles were determined on days 1 and 25 for bupropion and hydroxybupropion.
  
  
  RESULTS
  Baicalin administration increased hydroxybupropion maximum plasma concentration (C(max)) by 73% [90% confidence interval (CI), 44-108%; P < 0.01] and the area under the concentration time curve extrapolated to infinity (AUC(0-infinity)) of hydroxybupropion by 87% (90% CI, 48-137%; P < 0.01), with no change in the elimination half-life of hydroxybupropion. Baicalin increased the AUC(0-infinity) ratio of hydroxybupropion to bupropion by 63% (90% CI, 38-92%; P < 0.01).
  
  
  CONCLUSIONS
  Baicalin significantly induced CYP2B6-catalyzed bupropion hydroxylation, and the effects of baicalin on other CYP2B6 substrate drugs deserve further investigation.
authors.affiliation: Pharmacogenetics Research Institute, Institute of Clinical Pharmacology, Central South University, Changsha, Hunan, People's Republic of China.
authors.forename: Lan
authors.initials: L
authors.lastname: Fan
authors.forename: Jin-Chao
authors.initials: JC
authors.lastname: Wang
authors.forename: Feng
authors.initials: F
authors.lastname: Jiang
authors.forename: Zhi-Rong
authors.initials: ZR
authors.lastname: Tan
authors.forename: Yao
authors.initials: Y
authors.lastname: Chen
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Guo
authors.initials: G
authors.lastname: Wang
authors.forename: He-Ping
authors.initials: HP
authors.lastname: Lei
authors.forename: Dong-Li
authors.initials: DL
authors.lastname: Hu
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.forename: Hong-Hao
authors.initials: HH
authors.lastname: Zhou
mesh_terms: D000328:Adult; D019540:Area Under Curve; D001189:Aryl Hydrocarbon Hydroxylases / Q000096:biosynthesis* / Q000187:drug effects*; D016642:Bupropion / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism* / Q000493:pharmacokinetics; D065702:Cytochrome P-450 CYP2B6; D018765:Dopamine Uptake Inhibitors / Q000378:metabolism; D004790:Enzyme Induction / Q000187:drug effects; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology*; D005966:Glucuronidase / Q000037:antagonists & inhibitors; D006239:Haplotypes; D041743:Herb-Drug Interactions; D006801:Humans; D006900:Hydroxylation / Q000187:drug effects; D008297:Male; D010089:Oxidoreductases, N-Demethylating / Q000096:biosynthesis* / Q000187:drug effects*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D020641:Polymorphism, Single Nucleotide; D013997:Time Factors
chemical_list: D018765:Dopamine Uptake Inhibitors; D005419:Flavonoids; D010936:Plant Extracts; D016642:Bupropion; C038044:baicalin; D001189:Aryl Hydrocarbon Hydroxylases; C585599:CYP2B6 protein, human; D065702:Cytochrome P-450 CYP2B6; D010089:Oxidoreductases, N-Demethylating; D005966:Glucuronidase; C496215:radafaxine