Western blot analysis demonstrated that Cos, Dehy, CD, and VOSL treatment all can increase the phosphorylation level of 14-3-3 protein in breast cancer cells. As 14-3-3 protein is a G2/M checkpoint regulator, which can regulate cell cycle progression and promote cell apoptosis171819. Therefore, we thought Cos, Dehy, CD, and VOSL treatment should induce breast cancer cell cycle arrest. The results of cell cycle analysis were shown in Fig. 6A and B, which verified our speculation. IC10 of tested compound treatment did not change the progression of breast cancer cell cycle, interestingly, IC30 of Cos or Dehy treatment was apt to induce G2/M phase arrest, however IC50 of Cos or Dehy treatment was apt to induce S phase arrest. Moreover, IC50 of CD can significantly induce S phase arrest for MCF-7 cells and significantly induce S phase and G2/M phase arrest for MDA-MB-231 cells. IC50 of VOSL treatment can significantly induce S phase and G2/M phase arrest for the two breast cancer cell lines.