RESUMO
OBJECTIVE To investigate the effect and its mechanism of laminaria japonica polysaccharides(LJP) on human laryngeal carcinoma cell Tu212 growth. METHODS The laryngeal squamous cell Tu212 in logarithmic growth phase were treated by laminaria japonica polysaccharides(80, 160, 320 μg/ml) and cisplatin(1.8 mg/L). The MTT assay was used to evaluate cell growth inhibition rate after 24h, 48h and 72h. The flow cytometry with PI staining were used to estimate cell cycle distribution after 48h. The fluorescent microscopy was used to estimate cell apoptosis after 48h. The western blot was used to evaluate the expressions of Cyclin B1 and Bcl-2. RESULTS The cell proliferation was inhibited by cellular LJP in a dose and time dependent manner. Tu212 cells proliferation were stopped at the G2/M phase treated with LJP after 48h. Cell apoptosis was observed clearly by f luorescent microscope after 48h. The expressions of Cyclin B1 and Bcl-2 were suppressed significantly treated with LJP after 48 h. All of the differences were significant(P <0.05). CONCLUSION LJP has inhibitive effects on the Tu212 cells, this mechanism was probably through inhibition of the proliferation and promotion of the apoptosis.