Effect of Molecular Mass on Antitumor Activity of Heteropolysaccharide from Poria cocos
Lina ZHANG,IJ Li CHEN,’ Xi.a0jUall XU,1 Fanbo ZENG,2 and Peter Chi Keung CHEUNG3
IDepartment of Chemistry, Wuhan University, 2Tongji Medical College, Huazhong University of Science and Technology, 3Department of Biology, Chinese University of Hong Kong, Hong Kong
A water-soluble heteropolysaccharide ac-PCMO from Poria cocos was successfully fractionated using a preparative size exclusion chromatography (SEC) column, and their weight-average molecular mass (Mw) was characterized by analytical SEC combined with laser light scattering (SEC-LLS). The results indicate that the fractions having relatively high Mw, exhibited higher inhibition ratio in vivo antitumor activity than those having Mw, below 3.29 x 104. However, the relatively low molecular mass was beneficial to the in vitro antitumor activity. Moreover, ac-PCMO has a significantly higher enhancement ratio of the body weight than 5-fiuorouracil, and its 50% lethal dose is above 1250 mg/kg, indicating a nontoxic nature.