Mechanistic Studies of Antiproliferative Effects of <i>Salvia triloba</i> and <i>Salvia dominica</i> (Lamiaceae) on Breast Cancer Cell Lines (MCF7 and T47D)

Ethanol extracts obtained from two Salvia species, S. triloba and S. dominica, collected from the flora of Jordan, were evaluated for their antiproliferative activity against MCF7 and T47D breast cancer cell lines by the sulforhodamine B assay. The ethanol extracts were biologically active with IC₅₀ values of (29.89 ± 0.92) and (38.91 ± 2.44) μ g/mL for S. triloba against MCF7 and T47D cells, respectively, and (5.83 ± 0.51) and (12.83 ± 0.64) μ g/mL for S. dominica against MCF7 and T47D cells, respectively.

Flow cytometry analysis and the annexinV-propidium iodide (PI) assay revealed apoptosis-mediated, and to a lesser extent necrosis-induced, cell death by the S. triloba and S. dominica ethanolic extracts in T47D cells. The mechanism of apoptosis was further investigated by determining the levels of p53, p21/WAF1, FasL (Fas ligand), and sFas (Fas/APO-1). The extract from S. triloba induced a more pronounced enrichment in cytoplasmic mono- and oligonucleosomes than that from S. dominica (p < 0.05) in T47D cells. In response to the extract from S. dominica, but not from S. triloba, the proapoptotic efficacy was specifically regulated by p21. Extracts from both Salvia spp. did not enhance p53 levels, and apoptosis induced by them was not caspase-8- or sFas/FasL-dependent. Thus, our findings indicate that S. triloba and S. dominica ethanolic extracts may be useful in breast cancer management/treatment via proapoptotic cytotoxic mechanisms.