New potent and selective cytochrome P450 2B6 (CYP2B6) inhibitors based on three-dimensional quantitative structure-activity relationship (3D-QSAR) analysis.
OBJECTIVE
The cytochrome P450 2B6 (CYP2B6) enzyme metabolises a number of clinically important drugs. Drug-drug interactions resulting from inhibition or induction of CYP2B6 activity may cause serious adverse effects. The aims of this study were to construct a three-dimensional structure-activity relationship (3D-QSAR) model of the CYP2B6 protein and to identify novel potent and selective inhibitors of CYP2B6 for in vitro research purposes.


METHODS
The inhibition potencies (IC(50) values) of structurally diverse chemicals were determined with recombinant human CYP2B6 enzyme. Two successive models were constructed using Comparative Molecular Field Analysis (CoMFA).


RESULTS
Three compounds proved to be very potent and selective competitive inhibitors of CYP2B6 in vitro (IC(50)<1 microM): 4-(4-chlorobenzyl)pyridine (CBP), 4-(4-nitrobenzyl)pyridine (NBP), and 4-benzylpyridine (BP). A complete inhibition of CYP2B6 activity was achieved with 0.1 microM CBP, whereas other CYP-related activities were not affected. Forty-one compounds were selected for further testing and construction of the final CoMFA model. The created CoMFA model was of high quality and predicted accurately the inhibition potency of a test set (n=7) of structurally diverse compounds.


CONCLUSIONS
Two CoMFA models were created which revealed the key molecular characteristics of inhibitors of the CYP2B6 enzyme. The final model accurately predicted the inhibitory potencies of several structurally unrelated compounds. CBP, BP and NBP were identified as novel potent and selective inhibitors of CYP2B6 and CBP especially is a suitable inhibitor for in vitro screening studies.
Korhonen
L E
LE
Department of Pharmacology and Toxicology, University of Kuopio, Kuopio, Finland. laura.korhonen@uku.fi
Turpeinen
M
M
Rahnasto
M
M
Wittekindt
C
C
Poso
A
A
Pelkonen
O
O
Raunio
H
H
Juvonen
R O
RO
D065702:Cytochrome P-450 CYP2B6; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000378:metabolism; D006801:Humans; D008862:Microsomes, Liver / Q000201:enzymology; D008958:Models, Molecular; D021281:Quantitative Structure-Activity Relationship
D065607:Cytochrome P-450 Enzyme Inhibitors; D018076:DNA, Complementary; D004791:Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System; C585599:CYP2B6 protein, human; D065702:Cytochrome P-450 CYP2B6