Cyanidin-3-O-glucoside chloride acts synergistically with luteolin to inhibit the growth of colon and breast carcinoma cells.

In this study, we investigated whether the combination of cyanidin-3-O-glucoside chloride and luteolin could inhibit the growth of HCT-8 colon and MCF-7 breast carcinoma cells, and whether the effect of the combination was greater than the effect of either drug on its own. Growth inhibition was assessed using the CCK-8 assay, level of apoptosis and cell cycle distribution were determined using flow cytometry, and the mechanism of apoptosis induction was explored using a colorimetric assay of caspases-3 and -9. Experiments indicated that combination treatment inhibited proliferation and increased apoptosis in both cell lines to a greater extent than either drug on its own. These results suggest that luteolin and cyanidin-3-O-glucoside chloride synergistically inhibitthe growth of colon cancer and breast cancer cells. This work justifies further effort to develop this potential combination therapy.