Synergistic Cytotoxicity between Elephantopus scaber and Tamoxifen on MCF-7-Derived Multicellular Tumor Spheroid

Figure 1

Representative MTT assay showing the interaction between various combinations of E. scaber ethanol extract (ES) and tamoxifen citrate (TC) in MCF-7 multicellular tumor spheroidal (MCTS) cultures after 4 days of incubation in vitro. The concentrations of E. scaber are indicated on the χ-axis, while each line represents viability of cells after treatment by E. scaber alone (×) or by 1.56 μg/mL (▲), 3.125 μg/mL (■), or 6.25 μg/mL (♦) of tamoxifen in combination with increasing concentrations of the extract. Cell viability was determined by comparing to the survival of cells in the untreated (negative control) cultures, which was normalized to 100%. The results are presented as means ± SEM from three independent replicates.