Format

Send to

Choose Destination
J Pharmacol Exp Ther. 2018 Sep;366(3):446-457. doi: 10.1124/jpet.118.249557. Epub 2018 Jul 5.

A Specific Probe Substrate for Evaluation of CYP4A11 Activity in Human Tissue Microsomes and a Highly Selective CYP4A11 Inhibitor: Luciferin-4A and Epalrestat.

Author information

1
Department of Pharmacy, Shinshu University Hospital, Matsumoto, Japan (S.Y., S.O.); Department of Biochemical Pharmacology and Toxicology, Graduate School of Medicine, Shinshu University, Matsumoto, Japan (S.Y., S.K., S.O.); and Department of Hygienic Chemistry, Faculty of Pharmaceutical Sciences, Hokuriku University, Kanazawa, Japan (N.A., M.S., K.I., K.W.) syamaori@shinshu-u.ac.jp.
2
Department of Pharmacy, Shinshu University Hospital, Matsumoto, Japan (S.Y., S.O.); Department of Biochemical Pharmacology and Toxicology, Graduate School of Medicine, Shinshu University, Matsumoto, Japan (S.Y., S.K., S.O.); and Department of Hygienic Chemistry, Faculty of Pharmaceutical Sciences, Hokuriku University, Kanazawa, Japan (N.A., M.S., K.I., K.W.).

Abstract

The specificity of cytochrome P450 4A11 (CYP4A11) against luciferin-4A O-demethylation in human liver microsomes (HLMs) and human renal microsomes (HRMs) and selectivity of CYP4A11 inhibition by epalrestat were investigated. Kinetic analysis of luciferin-4A O-demethylation yielded Vmax and S50 values of 39.7 pmol/min per milligram protein and 43.2 μM for HLMs (Hill coefficient 1.24) and 39.4 pmol/min per milligram protein and 33.8 μM for HRMs (Hill coefficient 1.34), respectively. Among the selective CYP inhibitors tested, HET0016 (CYP4 inhibitor) exclusively inhibited luciferin-4A O-demethylation by HLMs and HRMs. Furthermore, anti-CYP4A11 antibody nearly abolished the activity of both tissue microsomes. Luciferin-4A O-demethylase activity of HLMs was significantly correlated with lauric acid ω-hydroxylase activity, a marker of CYP4A11 activity (r = 0.904, P < 0.0001). Next, effects of epalrestat on CYP-mediated drug oxidations were examined. Epalrestat showed the most potent inhibition against CYP4A11 (IC50 = 1.82 μM) among the 17 recombinant enzymes tested. The inhibitory effect of epalrestat on CYP4A11 was at least 10-fold stronger than those on CYP4F2, CYP4F3B, and CYP4F12. For known CYP4 inhibitors, in contrast, HET0016 inhibited the activities of CYP4A11 and CYP4F2 (IC50 = 0.0137-0.0182 μM); 17-octadecynoic acid reduced activities of CYP4A11, CYP4F2, CYP4F3B, and CYP4F12 to a similar extent (IC50 = 5.70-17.7 μM). Epalrestat selectively and effectively inhibited the CYP4A11 activity of HLMs (IC50 = 0.913 μM) and HRMs (IC50 = 0.659 μM). These results indicated that luciferin-4A O-demethylase activity is a good CYP4A11 marker of HLMs and HRMs, and that epalrestat is a more selective CYP4A11 inhibitor compared with known CYP4 inhibitors.

PMID:
29976573
DOI:
10.1124/jpet.118.249557

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center