Collect. Czech. Chem. Commun. 2000, 65, 1183-1190

Cytochromes P450 Involved in Cyclophosphamide, Paclitaxel and Docetaxel Metabolism in Rats

Lucie Bořek-Dohalskáa, Ivan Gutb,*, Pavel Součekb, Zdeněk Rothb and Petr Hodeka

a Department of Biochemistry, Faculty of Science, Charles University, 128 40 Prague 2, Hlavova 2030, Czech Republic
b National Institute of Public Health, Center of Industrial Hygiene and Occupational Diseases, Biotransformation Group, 100 42 Prague 10, Šrobárova 48, Czech Republic


We investigated involvement of cytochromes P450 (CYPs) of rat liver microsomes in metabolism of two anticancer drugs, paclitaxel (PCT) and docetaxel (DTX), by an indirect method. This method is based on the presumption that the compound competitively inhibiting oxidation of the CYP-selective substrate should also be a substrate for the CYP enzyme. The validity of this approach was confirmed using the model drug, cyclophosphamide (CPA). Indeed, CPA competitively inhibited oxidation of substrates specific for CYP2B1 and CYP3A1/2, enzymes previously reported to be capable of metabolizing CPA. Using this method, we identified CYP enzymes participating in PCT and DTX metabolism. The CYP2D1/2/3 and CYP3A1/2 are enzymes oxidizing PCT while CYP3A1/2 and CYP2E1 are responsible for metabolism of DTX. Here, we report a suitable method serving for easy and fast estimation of CYP enzymes involved in drug metabolism.

Keywords: Cytochrome P450; Cyclophosphamide; Paclitaxel; Docetaxel; Taxanes; Enzyme inhibition; Metabolism; Antitumor drugs; Biotransformations.

References: 36 live references.