title: Effect of free radicals on the biological action of genistein in vitro and synergism with mitomycin C.
abstract: BACKGROUND
  The effect of oxidizing and reducing free radicals on the biological properties of genistein (GEN) were investigated in vitro.
  
  
  METHODS
  MCF-7 cells were treated with GEN (5 micromol or 40 micromol) and/or mitomycin C (MMC; 2.5 micromol). For testing a possible radiosensitizing and synergistic effect of GEN in relation to MMC, a radiation dose of gamma-rays was applied up to 8 Gy. In order to produce the desired free radicals, the media were saturated with: (i) air (46% OH and 54% O2(*-)), (ii) N2O (90% OH, 10% H), or (iii) argon (44% e(-)(aq), 10% H and 46% OH). The survival fractions of the cells were determined by clonogenic assay.
  
  
  CONCLUSIONS
  GEN was found to be able to sensitize MCF-7 cells against the action of reducing (e(-)(aq), H, R(*)) as well as of oxidizing (OH, O2(*-)) free radicals. This ability was enhanced with increasing GEN concentration. Moreover, GEN acted synergistically with MMC in reducing as well as in oxidizing environments.
authors: Section of Radiation Biology, Department of Nutrition Science, The University of Vienna, UZA II, Althanstr. 14, A-1090 Vienna, Austria.
authors: Johannes
authors: J
authors: Hartmann
authors: Nikola
authors: N
authors: Getoff
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000532:radiotherapy*; D045744:Cell Line, Tumor; D003131:Combined Modality Therapy; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D004347:Drug Interactions; D004357:Drug Synergism; D005260:Female; D005609:Free Radicals / Q000378:metabolism*; D005720:Gamma Rays; D019833:Genistein / Q000008:administration & dosage; D006801:Humans; D007700:Kinetics; D016685:Mitomycin / Q000008:administration & dosage; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014867:Water
chemical_list: D005609:Free Radicals; D011838:Radiation-Sensitizing Agents; D014867:Water; D016685:Mitomycin; D019833:Genistein