Induction of cytochrome P450 2B6 activity by the herbal medicine baicalin as measured by bupropion hydroxylation.
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.
Fan
Lan
L
Pharmacogenetics Research Institute, Institute of Clinical Pharmacology, Central South University, Changsha, Hunan, People's Republic of China.
Wang
Jin-Chao
JC
Jiang
Feng
F
Tan
Zhi-Rong
ZR
Chen
Yao
Y
Li
Qing
Q
Zhang
Wei
W
Wang
Guo
G
Lei
He-Ping
HP
Hu
Dong-Li
DL
Wang
Dan
D
Zhou
Hong-Hao
HH
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
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