Differential response of breast cancer cell lines to Kigelia africana, Ximenia caffra and Mimusops zeyheri seed oils

Breast cancer is the most common cancer among women worldwide. The survival rate of breast cancer is higher in first-world countries than in developing countries, which still rely on ethnomedicine. The seed oils of Kigelia africana, Mimusops zeyheri and Ximenia caffra previously demonstrated anti-proliferative effects on Caco-2 and HEK-293 cells in vitro. We determined the effects of these seed oils on hormone-dependent (MCF-7) and hormone-independent (MDA-MB-231) breast cancer cells. Different seed oil concentrations and different incubation times were evaluated. While the seed oils concentrations had no significant cytotoxicity or effect on MDA-MB-231 and MCF-7 viability; oil type and incubation time showed significant effects. Kigelia africana and X. caffra seed oils induced the greatest cytotoxic effects on hormone-independent MDA-MB-231 breast cancer cells, while X. caffra and M. zeyheri seed oils induced a growth inhibitory effect on hormone-dependent MCF-7 breast cancer cells. These effects are dependent on oil type/composition, duration of exposure and cell phenotype.