Dichloromethane Fraction of Vernonia amygdalina Delile Synergistically Enhances Cytotoxicity of Doxorubicin on 4T1 Triple Negative Breast Cancer Cells through Apoptosis Induction and Cell Cycle Modulation

Doxorubicin (Dox) belongs to the chemotherapeutics agent that is commonly used to cure non-specific markers of cancers, including Triple Negative Breast Cancers (TNBC). Due to its toxicity to normal cells, the use of Dox is usually accompanied by another agent to increase the potency or to reduce the adverse effects. This study investigated the potential of Africa Leaf (Vernonia amygdalina Delile) extracts in combination treatment with Dox to increase the cytotoxicity in accordance with cell cycle modulation and apoptosis induction on TNBC cells. The MTT cell viability assay on 4T1 and MDA-MB-231 cells confirmed that only dichloromethane (DCM) fraction showed cytotoxic activities on both cells in a low grade. The DCM fraction increased the cytotoxic activity of Dox on 4T1 cells in a synergistic manner. The synergistic effect correlated with its activities in cell cycle modulation to accumulate the cells in sub-G1 phase and significantly induced apoptosis. In conclusion, the DCM fraction exhibits potential to be a co-chemotherapeutics agent for Dox to suppress TNBC cells growth through apoptosis induction.