RESUMO
Objective: To investigate the effects of rosmarinic acid (RosA) on the proliferation and apoptosis of human colon cancer HCT-8 cells, and explore the related mechanisms. Methods: The proliferation of HCT-8 cells was detected by CCK-8 assay at different concentrations of RosA for different time periods. The apoptosis rates of HCT-8 cells and the expression of related proteins were investigated after the treatment of RosA at 15, 45, and 75 μmol/L for 72 h according to the CCK-8 results. The apoptosis rates of HCT-8 cells were detected by FCM. The mRNA expressions of p53, Bax, and Puma were detected by RT-qPCR. The protein levels of p53, Bax, Puma, and active Caspase-9 were detected by Western blotting. Results: RosA could inhibit the proliferation of human colon cancer cells HCT-8 in a time- and dose-dependent manner. RosA at 15 and 45 μmol/L mainly induced early apoptosis (P < 0.01), RosA at 75 μmol/L mainly induced late apoptosis (P < 0.01). RosA could up-regulate the mRNA expression of Puma in a dose-dependent manner. RosA at 45 and 75 μmol/L increased the mRNA expression of p53 and Bax (P < 0.05). RosA could up-regulate the protein levels of Puma, Bax, and active Caspase-9 in a dose-dependent manner. RosA at 75 μmol/L could significantly increase the protein expression of p53 (P < 0.05). Conclusion: RosA can significantly inhibit the proliferation of HCT-8 cells by inducing the apoptosis. The apoptosis-inducing proteins of p53, Puma, Bax, and active Caspase-9 induce the apoptosis of cells.
RESUMO
Objective: To investigate the effects of magnolol in combination with 5-fluorouracil (5-FU) on the proliferation of human colon cancer HCT-8 cells and the expression of secreted frizzled-related protein-4 (SFRP-4). Methods: After treatment with magnolol and 5-FU alone or magnolol in combination with 5-FU, the proliferation of colon cancer HCT-8 cells was detected by MTT method, and the cell cycle distribution and the apoptosis of HCT-8 cells were examined by flow cytometry (FCM) and Hoechst 33258 nucleic acid staining, respectively. The expression levels of SFRP-4 and p-catenin proteins in HCT-8 cells were examined by Western blotting. Results: The proliferation of HCT-8 cells was inhibited by magnolol and 5-FU alone or mamgnolol in combination with 5-FU (all P 2/M phases were decreased in 5-FU alone group and the combination treatment group (both P < 0.05). The expression levels of SFRP-4 in HCT-8 cells in all three treatment groups were higher than that in the blank control group (without any treatment) (P < 0.05), while the expression level of p-catenin in HCT-8 cells in combination treatment group was lower than those in 5-FU and magnolol alone groups (P < 0.05). Conclusion: Magnolol in combination with 5-FU can enhance the inhibition effect on proliferation of human colon cancer HCT-8 cells, and arrest the cells at G0/G1 phase. This mechanism may be related to regulating the expressions of SFRP-4 and p-catenin proteins.