Figure 4.

Effect of both H. cordata and P. ribesioides extracts on breast cancer cell growth inhibition and cell cycle disruption. (A) Colony formation assay. MCF-7 and MDA-MB-231 were treated with non-toxic concentrations of both Houttuynia cordata Thunb. (HCT) and Piper ribesioides Wall. (PR) extracts for 24 h, washed by PBS and cultured for seven days. The colonies were counted and compared with the control. (B) For cell cycle assay, the cells were treated with the same condition in the colony formation assay and analyzed by flow cytometry after the cells were stained with propidium iodide. Cell numbers are presented as a percentage of the total analyzed cells. Each value is presented as mean ± SD from three independent experiments. Data are the means ± SD. * p < 0.05, ** p < 0.01, and *** p < 0.001 vs. control.