Cytochromes P450 reconstituted with NADPH: P450 reductase mimic the activating and detoxicating metabolism of the anticancer drug ellipticine in microsomes
Jazyk angličtina Země Švédsko Médium print
Typ dokumentu hodnotící studie, časopisecké články, práce podpořená grantem
PubMed
17159771
PII: NEL270806A03
Knihovny.cz E-zdroje
- MeSH
- adukty DNA metabolismus MeSH
- antitumorózní látky farmakokinetika MeSH
- biologické modely MeSH
- elipticiny farmakokinetika MeSH
- I. fáze biotransformace * MeSH
- jaterní mikrozomy chemie metabolismus MeSH
- králíci MeSH
- krysa rodu Rattus MeSH
- NADP chemie metabolismus MeSH
- NADPH-cytochrom c-reduktasa izolace a purifikace metabolismus MeSH
- systém (enzymů) cytochromů P-450 chemie izolace a purifikace metabolismus MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- Názvy látek
- adukty DNA MeSH
- antitumorózní látky MeSH
- elipticiny MeSH
- ellipticine MeSH Prohlížeč
- NADP MeSH
- NADPH-cytochrom c-reduktasa MeSH
- systém (enzymů) cytochromů P-450 MeSH
OBJECTIVES: Ellipticine is a potent antineoplastic agent exhibiting multiple action mechanisms. Recently, we found that after cytochrome P450 (CYP)-mediated oxidation ellipticine forms covalent DNA adducts. Ellipticine oxidation by isolated CYP and its binding to DNA is the target of this study. METHODS: High performance liquid chromatography (HPLC) was employed for separation and characterization of ellipticine metabolites generated by CYPs. The (32)P-postlabeling technique was utilized to determine ellipticine-DNA adducts. RESULTS: Purified CYP enzymes reconstituted with NADPH:CYP reductase oxidized ellipticine to up to five metabolites, 7-hydroxy-, 9-hydroxy-, 12-hydroxy-, 13-hydroxyellipticine and ellipticine N(2)-oxide. However, only CYP1A1 was capable to form all metabolites. Using the reconstituted enzymatic system, we demonstrated that the detoxication ellipticine metabolites, 7-hydroxyellipticine and 9-hydroxyellipticine, are mainly generated by CYP1A1 and 1A2, while those responsible for DNA binding, 13-hydroxy-, 12-hydroxyellipticine and ellipticine N(2)-oxide, by CYP3A1 and 2C3. Likewise, the most efficient CYPs forming DNA adducts from ellipticine were CYP3A1 and 2C3. CONCLUSIONS: The results showed that the system of purified CYPs reconstituted with NADPH: CYP reductase proved for ellipticine oxidation provide a true reflection of the situation in the microsomal membrane.
