Active Fractions of Dichloromethane Extract of Artemisia Aucheri Inhibit Proliferation of Human Breast Cancer MCF-7 Cells via Induction of Apoptosis

The antiproliferative effect of dichloromethane extract of Artemisia aucheri (A. aucheri) has been demonstrated previously on human cancerous cell lines. In the current study, further fractionation was carried out on the dichloromethane extract of A. aucheri and their cytotoxic effects were evaluated on three human cancer cell lines; SKNMC, MCF-7, and A2780. Cell viability was determined by MTT assay and activation of caspases was evaluated by spectrophotometry. Quantitative real time RT-PCR was used to evaluate the genes expression. Detection of DNA fragmentation was carried out by flow cytometry. The obtained results showed that fractions 5 and 7 (F5 and F7) have a potent cytotoxic effect, especially against MCF-7 cells. F5 and F7 also induced apoptosis through the DNA fragmentation and mitochondrial membrane potential (MMP) disruption in MCF-7 cells. The caspase-3, 9 enzyme activities were also increased after exposure to F5 and F7. Moreover, caspase-8 activity increased significantly after exposure to F7 but not F5. The level of mRNA expressions of Bax and Smac/DIABLO was increased after exposure to both fractions. A detectable decrease was also observed in the mRNA expression of Bcl-2 after exposure to F7. No change was observed in the level of mRNA expressions of tumor suppressor P53 after exposure to F7. Therefore, the cell cycle arrest and apoptosis induced by F7 could probably be mediated through a p53-independent mechanism. Taken together, these observations demonstrated that the cytotoxic effect of F5 and F7 on MCF-7 cells is likely exerted via apoptotic cell death.