Licoflavone C attenuates the genotoxicity of cancer drugs in human peripheral lymphocytes.

Flavonoids exhibit a wide spectrum of biological activities that can lead to beneficial effects for human health. The search for cytotoxic, genotoxic and/or antimutagenic natural compounds is therefore of great relevance, especially in cancer chemotherapy. In view of this, we screened the potential genotoxicity/antigenotoxicty of licoflavone C (LFLC) - a naturally occurring prenyl-flavone extracted from Genista ephedroides - using the micronucleus (MN) assay on stimulated and cytochalasin B-blocked human lymphocytes. LFLC did not increase the spontaneous MN level up to 600 microM final concentration where a strong toxicity was seen to occur. We therefore performed an antigenotoxicity assay against the two mutagenic anticancer drugs, mitomycin C (MMC) and daunorubicin (DAU), using two non-toxic LFLC concentrations (0.1 microM and 1.0 microM). The MN frequencies induced by 0.025 microg/ml or 0.05 microg/ml DAU were significantly lowered by 45.4% or 46.6% and 41.8% or 44.8% at LFLC 0.1 and 1.0 microM, respectively. After treatment with 0.085 microg/ml or 0.17 microg/ml MMC, we detected a reduction in genotoxicity of 35.1% or 37.0% and of 38.0% or 35.8% at LFLC 0.1 and 1.0 microM, respectively. In conclusion, LFLC was proven to be protective toward the chromosome damage induced by DAU or MMC in cultured human peripheral lymphocytes. (c) 2008 John Wiley & Sons, Ltd.