Abstract: Swainsonine have a wide range of antitumor and immunomodulatory effects.The apoptosis-inducing effect of swainsonine on human laryngeal carcinoma Hep-2 cells and its mechanisms were investigated in this study.Different concentrations of swainsonine was applied to Hep-2 cells for 24 h,the cells activity was detected by MTT assay.Cells morphology was observed under a fluorescence microscope.Cell apoptosis was detected by Annexin V-FITC/PI double labeling.JC-1 was used to detect the mitochondrial membrane potential.The mRNA and protein levels of Bax and XIAP were measured by Real-time PCR and Western blot respectively.Swainsonine inhibited the proliferation and induced the apoptosis of Hep-2 cells in a dose-dependent manner in a certain concentration range.The different levels of morphology change of apoptosis were observed.The eversion of phosphatidyl serine was aggravatingly intensified,and mitochondrial membrane potential decreased.The mRNA and protein expression level of Bax increased.The mRNA and protein expression level of XIAP decreased.Hence,it was concluded that swainsonine induced apoptosis through the mitochondrial pathway and dependent on the regulation of the proteins levels of Bax and XIAP.

Key words: swainsonine, Hep-2 cells, apoptosis, mitochondrial pathway