Anti-Oxidation Effects Of Se-containing Polysaccharide SeGLP-2B-1 On Apoptosis Of Breast Cancer MCF-7 Cells

Selenium (Se) is an essential trace element for human being. Se deficiency induces many diseases, such as cancer, cardiovascular disease. In many biological functions of Se, the anticarcinogenic properties of selenium has been widespread concerned. The chemical forms of Se include organic and inorganic Se. The organic Se compounds include Se-containing polysaccharides, Se-containing proteins etc., and the inorganic Se compounds include selenonic acid and the selenite salt. Although inorganic Se compounds are considered as effective anti-cancer drugs, organic Se are being pay highly attention for its higher bioavailability and is safer than inorganic Se species. As a kind of organic Se, Se-containing Polysaccharide from Se-enriched Ganoderma lucidum concurrently has the function of Se and polysaccharide, and therefore, it is crucial to develop suitable organic Se dietary sources for humans.After co-cultivation of ganoderma with selenium, we detached and purified an Se-containing Polysaccharide SeGLP-2B-1 with anticancer activity. The first purpose of present study is to determine the cytotoxic effects of Se-containing Polysaccharide SeGLP-2B–1, at various concentrations (0.0225μM,0.045μM,0.09μM,0.18μM,0.27μM,0.36μM,0.45μM,0.54μM,0.64μM ) and different time-courses (24h,48h,72h respectively), against breast cancer cell line MCF-7. The results of MTT assay showed that the Se-containing Polysaccharide SeGLP-2B-1 inhibited the proliferation of breast cancer cells MCF-7 in a time-dependent and dose-dependent manner. The half inhibitory concentration (IC50) of SeGLP-2B–1 were 0.264 and 0.246μM in the time of 48h and 72h. Then, using DCFH-DA fluorescent probing and malondialdehyde (MDA) assay, the concentrations of intracellular ROS and MDA were detected to explore the possible involvment of ROS in SeGLP-2B-1 induced MCF-7 cell apoptosis.Experiment results show that with Se-containing Polysaccharide time-dependently enhanced selenium anti-oxidation, reduced content of ROS ( 72h detected ROS levels reached the lowest) and MDA.Se-containing Polysaccharide, SeGLP-2B-1, time-dependently increased the contant of antioxidant enzymes (SOD, CAT, GSH-Px) in MCF-7 cells. This partially proved the anti-oxidant ability of selenium, and speculated that the antioxidant effect of Se-containing Polysaccharide might be medited by enhanceing the activity of endogenous anti-oxidase in cells.