Cytotoxic and cancer chemopreventive potentials of the Anthonotha macrophylla P. Beauv aqueous extract on 7,12-dimethylbenz[a]anthracene-induced breast cancer in rats

Breast cancer is one of the leading causes of cancer deaths in women worldwide. Many women rely on plants as alternatives to prevent/treat cancer. Anthonotha macrophylla (Ceasalpiniaceae) is one of this ethnomedicinal plant used to cure cancer in Cameroon. This study was therefore undertaken to bring scientific evidence to this claim. The in vitro cytotoxicity of A. macrophylla aqueous extract was evaluated using resazurin reduction assay in five tumors and two non-tumor cell lines. Moreover, the chemopreventive potential of A. macrophylla aqueous extract was evaluated on 7,12 dimethylbenz[a]anthracene (DMBA) induced breast cancer in rats. The research focused on the incidence, burden, volume and histological analysis of breast tumors. In vitro, A. macrophylla extract exhibited cytotoxic effect in all tested cell lines with a CC₅₀ ~ 279 and 132 μg/mL in human (MCF-7 and MDA-MB-231) and rodent breast cancer cells, respectively after 24 h. In vivo, the untreated DMBA-rats presented 100% of tumor incidence, while no tumor was detected in normal rats. Interestingly, a seven-month oral administration of A. macrophylla extract at the doses of 75 and 150 mg/kg BW resulted in a significant decrease of tumor incidence (p < 0.01 and p < 0.05), burden (70.01% and 53.28%) and volume (p < 0.001 and p < 0.01) compared to DMBA rats. The presence of polyphenols in the aqueous extract of Anthonotha macrophylla, as well as its antiradical properties, may account for its antitumor effects. These results therefore support the traditional use of Anthonotha macrophylla against breast cancer.