Comparison of the cytotoxic effect of SC/D-F9 with tamoxifen, paclitaxel and doxorubicin in breast cancer cells. MCF-7 and MDA-MB-231 cells were treated with 8.5 and 10.0 μg/ml SC/D-F9, respectively, 5 and 15 μM tamoxifen (T5, T15), 10 and 100 nM paclitaxel (P10, P100) and 50 and 250 nM doxorubicin (Dx50, Dx250), for 24 and 48 hr. The control cultures contained the solvent (0.1% DMSO). The percentages of cell death induced were determined using the LDH release assay and each data represents the mean ± SD from three independent experiments. Statistical analysis was determined using the Student T test with * p < 0.05; ** p < 0.01; *** p < 0.001, compared to control.