Growth Inhibition and Apoptosis Induction of Salvia chloroleuca on MCF-7 Breast Cancer Cell Line

Fragrant species of the genus Salvia have been attributed many medicinal properties, which include anticancer activity. In the present study, cytotoxic properties of total methanol extract of Salvia chloroleuca Rech. f. & Aellen and its fractions were investigated on MCF-7, a breast carcinoma cell line. Malignant and non-malignant cells were cultured in RPMI medium and incubated with different concentrations of plant extracts. Cell viability was quantitated by 3-(4,5-dimethylthiazol-2-yl) -5-(3-carboxymethoxyphenyl) -2-(4-sulphophenyl) -2H-tetrazolium (MTS) assay. Apoptotic cells were determined using propidium iodide (PI) staining of DNA fragmentation by flow cytometry (sub-G1 peak). S. chloroleuca inhibited the growth of malignant cells in a dose-dependent manner. Among solvent fractions of S. chloroleuca, the n-hexane and methylene chloride fractions were found to be more toxic compared to other fractions. S. chloroleuca-induced a sub-G1 peak in flow cytometry histogram of treated cells compared to control and DNA fragmentation suggested the induction of apoptosis. Administration of N-acetyl cysteine and vitamin C two ROS scavengers also resulted in significant inhibition of cytotoxicity induced by S. chloroleuca. These results support a mechanism whereby S. chloroleuca induces apoptosis of MCF-7 human breast cells through a ROS-mediated pathway.