ABSTRACT
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.
ABSTRACT
Objective:To investigate the relation of antiradiation effect of LJP and lymphocyte apoptosis. Methods:36 Wistar rats were randomly divided into 6 groups (n=6): control, model,and LJP given i.g.at 4 doses(100,200,300,400 mg/ kg bw) for 10d before whole-body irradiation with 9.0 Gy Co?-ray. 18h later,the effects of LJP on the indices of immune function of the irradiated rats 60 were measured. TUNEL and flow cytometry were used to study the effects of LJP on splenic lymphocyte apoptosis and immunohistochemical technique was used to detect the expression of Bcl-2 and the Bax protein. Results:LJP significantly modulated immune function in irradiated rats. The apoptosis ratio of splenic lymphocyte of the model group was higher than those of other groups. LJP could markedly inhibit the effects of irradiation on apoptosis and increase the ratio of bcl-2/bax protein in dose-effect manner. Conclusion:LJP could inhibit splenic lymphocyte apoptosis induced by irradiation, and its mechanism is associated with regulating the expression of bcl-2 and bax protein of splenic lymphocyte. Key word:laminaria japonica polysaccharides; irradiation; lymphocyte; apoptosis apoptosis-related genes