Inhibition of polymorphic human carbonyl reductase 1 (CBR1) by the cardioprotectant flavonoid 7-monohydroxyethyl rutoside (monoHER)

Pharm Res. 2008 Jul;25(7):1730-4. doi: 10.1007/s11095-008-9592-5. Epub 2008 May 1.


Purpose: Carbonyl reductase 1 (CBR1) reduces the anticancer anthracyclines doxorubicin and daunorubicin into the cardiotoxic metabolites doxorubicinol and daunorubicinol. We evaluated whether the cardioprotectant monoHER inhibits the activity of polymorphic CBR1.

Methods: We performed enzyme kinetic studies with monoHER, CBR1 (CBR1 V88 and CBR1 I88) and anthracycline substrates. We also characterized CBR1 inhibition by the related flavonoids triHER and quercetin.

Results: MonoHER inhibited the activity of CBR1 V88 and CBR1 I88 in a concentration-dependent manner. The IC(50) values of monoHER were lower for CBR1 I88 compared to CBR1 V88 for the substrates daunorubicin and doxorubicin (daunorubicin, IC(50)-CBR1 I88 = 164 microM vs. IC(50)-CBR1 V88 = 219 microM; doxorubicin, IC(50)-CBR1 I88 = 37 microM vs. IC(50)-CBR1 V88 = 59 microM; p < 0.001). Similarly, the flavonoids triHER and quercetin exhibited lower IC(50) values for CBR1 I88 compared to CBR1 V88 (p < 0.001). MonoHER acted as a competitive CBR1 inhibitor when using daunorubicin as a substrate Ki = 45 +/- 18 microM. MonoHER acted as an uncompetitive CBR1 inhibitor for the small quinone substrate menadione Ki = 33 +/- 17 microM.

Conclusions: The cardioprotectant monoHER inhibits CBR1 activity. CBR1 V88I genotype status and the type of anthracycline substrate dictate the inhibition of CBR1 activity.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Alcohol Oxidoreductases / antagonists & inhibitors*
  • Alcohol Oxidoreductases / genetics
  • Antibiotics, Antineoplastic / pharmacology
  • Cardiotonic Agents / pharmacology*
  • Data Interpretation, Statistical
  • Daunorubicin / pharmacology
  • Doxorubicin / pharmacology
  • Enzyme Inhibitors / pharmacology*
  • Genotype
  • Humans
  • Hydroxyethylrutoside / analogs & derivatives*
  • Hydroxyethylrutoside / pharmacology
  • Kinetics
  • Recombinant Proteins / chemistry


  • 7-monohydroxyethylrutoside
  • Antibiotics, Antineoplastic
  • Cardiotonic Agents
  • Enzyme Inhibitors
  • Hydroxyethylrutoside
  • Recombinant Proteins
  • Doxorubicin
  • Alcohol Oxidoreductases
  • Daunorubicin