<![CDATA[Doxorubicin is a commonly used chemotherapeutic agent in patients with breast cancer. The risk of side effect using of doxorubicin such as cardiomyopathy and congestive heart failure which can lead to death. One of the approach to overcome overloaded use of doxorubicin is the combined use with a chemopreventive agent (cochemotherapy), including the leaf extract of marigolds (Cosmos caudatus Kunth.). This research aims to reviewing the effect of the methanol extract of leaves of marigolds on the cytotoxic activity of doxorubicin in modulating cell cycle and apoptosis of breast cancer cells T47D. Determination of the cytotoxic activity of methanol extract of leaves of marigolds and doxorubicin as well as a combination of both conducted by MTT assay. modulation surveillance of cell cycle and apoptosis induction is done by using flowcytometry and analyzed by FACS Calibur program. Cytotoxicity assay single treatment of the methanol extract of leaves of marigolds produce use values of IC50 504,840 μg/ml, whereas IC50 values doxorubicin is 141,055 nM. The synergistic effect was shown a combination of methanol extract leaves marigolds and doxorubicin at concentrations of 84,17 μg/ml -23,5 nM; 84,17 μg/ml -47 nM; 126,25 μg/ml -23,5 nM; 252,5 μg/ml -35,25 nM and 252,5 μg/ml -71 nM with a combination index value (CI) consecutively of 0,5; 0,6; 0,6; 0,6 and 0,6. Observations modulation of cell cycle and apoptosis induction combination of methanol extract leaves marigolds and doxorubicin at concentrations of 84,17 μg/ml -23,5 nM, said that a combination of the methanol extract of leaves of marigolds and doxorubicin to inhibit the proliferation of cells in G2 / M phase and able to induce apoptosis of breast cancer cells T47D.Keywords: methanol extract of leaves of marigolds, doxorubicin, flowcytometry, cell cycle, apoptosis.]]>
