Effect of free radicals on the biological action of genistein in vitro and synergism with mitomycin C.
Anticancer Res. 2009 Aug;29(8):3179-83. PMID: 19661332
BACKGROUND: The effect of oxidizing and reducing free radicals on the biological properties of genistein (GEN) were investigated in vitro. MATERIALS AND 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. Results and CONCLUSION: 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.