Delayed growth of glioma by a polysaccharide from Aster tataricus involve upregulation of Bax/Bcl-2 ratio, activation of caspase-3/8/9, and downregulation of the Akt

In this study, a homogeneous polysaccharide (ATP-II), with a molecular weight of 3.4 x 10(4) Da, was successfully purified from Aster tataricus by DEAE-Sepharose CL-6B ion exchange and Sepharose CL-6B gel filtration chromatography. Monosaccharide component analysis indicated that ATP-II was composed of glucose, galactose, mannose, rhamnose, and arabinose in molar ratios of 2.1:5.2:2.1:1.0:1.2. We evaluated the anticancer efficacy and associated mechanisms of ATP-II on glioma C6 cells in vitro and in vivo. The results showed that treatment of C6 cells with ATP-II inhibited cell proliferation and this biological response came from induction of DAN damage and consequent inducing apoptosis. Likewise, oral ATP-II administration resulted in consistent regression of glioma tumors and induced apoptosis of transplanted tumor tissues by increasing the ratio of Bax/Bcl-2 and activation of caspase-3, caspase-8, and caspase-9 cascade. Importantly, the efficient downregulation of Akt, which is successfully detected in tumor tissues, is a unique contribution to retard the tumor growth by ATP-II. These data suggest that ATP-II may be a potential candidate for glioma treatment.