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Arzneimittelforschung 2004; 54(1): 78-83
DOI: 10.1055/s-0031-1296940
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Editio Cantor Verlag Aulendorf (Germany)

Drug-Drug Interactions Evaluated by a Highly Active Reconstituted Native Human Cytochrome P4503A4 and Human NADPH-Cytochrome P450 Reductase System

Thomas Haehner
a   Department of Physiological Chemistry, University of Ulm, Ulm, Germany
,
Mohamed Osman I. Refaie
b   Laboratory of Biomedical Analysis, Faculty of Science, University of Cairo, Cairo, Egypt
,
Dieter Müller-Enoch
a   Department of Physiological Chemistry, University of Ulm, Ulm, Germany
› Author Affiliations
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Publication History

Publication Date:
25 December 2011 (online)

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Summary

Catalytic activities of native human CYP3A4-mediated reactions as well as drug interactions were directly evaluated by isolated reconstituted human CYP3A4: NADPH-cytochrome P450 reductase systems. The SDS-PAGE pure CYP3A4 and human NADPH-cytochrome P450 reductase had been incorporated into a binary vesicular phospholipid system of di-lauroyl-phosphatidyl-choline and phosphatidyl-serine which had proven to achieve optimal nifedipine oxidase activity (19.6 nmol nifedipine oxidized x min−1 nmol CYP3A4−1). The IC50 values of ke-toconazole (CAS 65 277-42-1) (~3 μmol/1), quinidine (CAS 56-54-2) (~5 μmol/1), mifepristone (CAS 84 371-65-3) (~8 μmol/l), 17a-ethinylestradiol (CAS 57-63-6) (~17 μmol/1), Cimetidine (CAS 51 481-61-9) (~46 μmol/1), FK 506 (tacrolimus) (CAS 104 987-11-3) (~53 μmol/1), naring-enin (CAS 480-41-1) (~87 μmol/1), and cyclosporine A (CAS 59 865-13-3) (~90 μmol/l) indicate that all these drugs have an inhibitory effect on nifedipine (CAS 21 829-25-4) metabolism, whereas the drug quinine (CAS 130-95-0) did not elicit any significant inhibition.

Zusammenfassung

Bestimmung von Arzneimittelwechselwirkungen mit Hilfe von Rekonstitutions-systemen, die natives humanes CYP3A4 und humane NADPH-Cytochrom P450-Reduktase enthalten

Katalytische Aktivitäten CYP3A4-vermittelter Reaktionen und Arzneimittelechselwirkungen wurden mit Hilfe von Rekonstitutionssystemen, die isoliertes humanes CYP3A4 und humane NADPH-Cytochrom P450-Reduktase enthalten, direkt bestimmt. SDS-PAGE-gereinigtes CYP3A4 und die humane NADPH-Cytochrom P450-Reduktase wurden in ein binäres, die Phospholipide Dilaurylphos- phatidylcholin und Phosphatidylserin enthaltendes Rekonstitutionssystem inkorporiert. Mit diesem System konnten optimale katalytische Aktivitäten erreicht werden (19, 6 nmol oxidiertes Nifedipin x min−1 nmol CYP3A4−1). Die IC50-Werte von Ketokonazol (CAS 65 277-42-1) (~3 μmol/1), Chinidin (CAS 56-54-2) (~5 μmol/1), Mifepriston (CAS 84 371-65-3) (~8 μmol/1), 17a-Ethinylestradiol (CAS 57-63-6) (~17 μmol/1), Cimetidin (CAS 51 481-61-9) (~46 μmol/1), FK 506 (Tacrolimus) (CAS 104 987-11-3) (~ 53 μmol/1), Naringenin (CAS 480-41-1) (~ 87 μmol/1) und Cyclosporin A (CAS 59 865-13-3) (~ 90 μmol/1) zeigen, daß diese Substanzen den Nifedipin (CAS 21 829-25-4)-Metabolismus hemmen. Im Gegensatz dazu konnte Chinin (CAS 130-95-0) keine signifikante Hemmung verursachen.

Key words

Cytochrome P4503A4, reconstitution - Drug-drug interactions - NADPH-cytochrome P450 reductase, reconstitution - Nifedipine oxidation