Effects of Honokiol on the Proliferation and the Apoptosis Related Protein Expression of Caspase pathway in Human Colorectal Carcinoma Cell Line SW480 in vitro

Objective To assess the inhibitory effects of Honokiol on proliferation and inducing effect on caspase pathway in human colorectal carcinoma cell line SW480 in vitro. Methods Cultured SW480 cells were treated with Honokiol Under different concentration and time(24, 48, 72, 96 h). Cell proliferation was assessed by MTT colorimetric assay. Cell apoptosis was determined by flow cytometry (FCM) and Hoechst 33258 fluorescent staining. Caspase-3,-8,-9 activity were measured at different time points after Honokiol treatment. Results MTT assay demonstrated that the proliferation of SW480 cells were suppressed significantly by Honokiol in dose-and time-dependent manner (P 0.05). After treated with the drug for 24 h,48 h,and 72 h,the IC50 values were 54.36、44.72、36.20 μmol/L, respectively. After the cells were treated with Honokiol, the ratio of G0/G1 increased with the growing concentration of the drug, which showed the cells were arrested by Honokiol at G0/G1 phase. After treatment with Honokiol,typical apoptotic bodies in the cell nucleus were observed by Hoechst 33258 fluorescence staining. After SW480 cells were treated by Honokiol,protease activity assays of caspase family showed that Caspase-3,-8,-9 enzymes were stimulated and enzyme activities increase at different time points. Conclusion Honokiol can inhibit the proliferation and induce apoptosis of human cervical carcinoma SW480 cells through stimulating Caspase pathway.