title: The tyrosine kinase inhibitor nilotinib selectively inhibits CYP2C8 activities in human liver microsomes.
abstract: The tyrosine kinase inhibitor nilotinib was examined for its inhibition of cytochrome P450s (CYPs) in human liver microsomes and in human CYPs expressed in a baculovirus-insect cell system. Nilotinib demonstrated preferential inhibition of CYP2C8-mediated paclitaxel 6α-hydroxylation, rosiglitazone hydroxylation and amodiaquine N-deethylation in human liver microsomes, with IC₅₀ values of 0.4, 7.5 and 0.7 µM, respectively. The IC₅₀ value of nilotinib for paclitaxel 6α-hydroxylation was 20-fold lower than that of the other five tyrosine-kinase inhibitors tested. Nilotinib appears to display competitive inhibition against paclitaxel 6α-hydroxylation and amodiaquine N-deethylation, with estimated mean Ki values of 0.90 and 0.15 µM in human liver microsomes and 0.10 and 0.61 µM in recombinant human CYP2C8, respectively. These results are consistent with those of molecular docking simulations, where paclitaxel could not access the CYP2C8 catalytic site in the presence of nilotinib, but the binding of midazolam, a substrate of CYP3A4, to the catalytic site of CYP3A4 was not affected by nilotinib. The demonstrated inhibitory activity of nilotinib against CYP2C8 at concentrations less than those observed in patients who received nilotinib therapy is of potential clinical relevance and further in vivo exploration is warranted.
authors: Department of Pharmacology and PharmacoGenomics Research Center, Inje University College of Medicine.
authors: Min-Jung
authors: MJ
authors: Kim
authors: Jae-Won
authors: JW
authors: Lee
authors: Kyung-Suk
authors: KS
authors: Oh
authors: Chang-Soo
authors: CS
authors: Choi
authors: Kwang Hee
authors: KH
authors: Kim
authors: Won Seok
authors: WS
authors: Han
authors: Chang-No
authors: CN
authors: Yoon
authors: Eun Sook
authors: ES
authors: Chung
authors: Dong-Hyun
authors: DH
authors: Kim
authors: Jae-Gook
authors: JG
authors: Shin
mesh_terms: D001189:Aryl Hydrocarbon Hydroxylases / Q000037:antagonists & inhibitors*; D065727:Cytochrome P-450 CYP2C8; D006801:Humans; D020128:Inhibitory Concentration 50; D007700:Kinetics; D008862:Microsomes, Liver / Q000187:drug effects*; D062105:Molecular Docking Simulation; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011743:Pyrimidines / Q000493:pharmacokinetics / Q000494:pharmacology*
chemical_list: D011743:Pyrimidines; D001189:Aryl Hydrocarbon Hydroxylases; C450259:CYP2C8 protein, human; D065727:Cytochrome P-450 CYP2C8; D011505:Protein-Tyrosine Kinases; C498826:nilotinib