Centchroman (CC), a non-steroidal
oral contraceptive and a candidate
drug for
breast cancer, has been reported to exhibit partial to complete remission of lesions in 40.5% of
breast cancer patients. The potent anti-oestrogenic activity, negligible side-effects and anti-
breast cancer activity of CC prompted us to evaluate the
antimutagenic effects of this compound in a bacterial mutagenicity assay and CHO/
HPRT and AS52/GPT mutation assays in vitro and in vivo in female Swiss albino mice as measured by both sister chromatid exchange (SCE) and
chromosome aberrations (CA) against three known positive
mutagen compounds, dimethylbenz[a]
anthracene (DMBA),
cyclophosphamide (CP) and
mitomycin C (MMC). Antimutagenicity assays in Salmonella strains TA97a, TA100, TA98 and TA102 were carried out against commonly used known positive
mutagens,
sodium azide,
4-nitro-o-phenylenediamine, cumine
hydroperoxide,
2-aminofluorene and
danthron. A significantly reduced number of bacterial
histidine revertant colonies was observed in the plates treated with 0.1, 1, 5 and 10 microg/plate CC and a positive compound when compared with bacterial plates treated with the respective positive compound alone.
Ethyl methanesulfonate (EMS), a commonly used positive
mutagen for CHO/
HPRT and AS52/GPT gene mutation assays, was used for antimutagenicity assay in these cells. CC exhibited protective effects against the mutagenicity of EMS in these two mammalian cell mutation assays, CHO/
HPRT and AS52/GPT. In the in vivo studies, pretreatment with CC reduced DMBA-induced SCE and CA and CP- and MMC-induced CA when compared with the group treated only with the positive compounds. These results indicate that CC can reduce the mutagenic effects of known genotoxic compounds.