Synergistic interaction between quercetin and doxorubicin on MCF-7 human breast cancer cell line

Abstract

The effectiveness of doxorubicin has decreased due to resistance of cancer cells. One of the
natural ingredients that are proven to reduce the resistance to anticancer is quercetin. Quercetin
interacts with doxorubicin via a competition of P-glycoprotein (P-gp) transporter activity. The
aim of this study is to evaluate the interaction of quercetin and doxorubicin as cytotoxicity
effect on MCF-7 cells. Cytotoxicity test was conducted by the MTT method. Mechanism of
interaction between doxorubicin and quercetin was evaluated with isobologram analysis.
Doxorubicin and quercetin inhibited the growth of MCF-7 cells significantly. Doxorubicin and
quercetin respectively had IC50 of 21M and 103 M. The interaction of doxorubicin and quercetin
were characterized by the amount of doxorubicin IC50 equivalent and quercetin IC50 equivalent
less than 1 and the point-intercept of each IC50 notation equivalent plotted on the graph below
the additive line. Analysis of isobolograms indicated that the interaction doxorubisn and quercetin
in each of the ratios had synergy. Quercetin can be considered to be in a combination wit