Purification, characterization and anti-tumor activities of polysaccharides extracted from wild Russula griseocarnosa

The anti-tumor activity of a novel polysaccharide, PRG1-1, obtained from Russula griseocarnosa sporocarp was investigated in this paper. PRG1-1 has a molecular weight of 630kDa and was extracted and purified using DEAE-cellulose and gel filtration chromatography from crude polysaccharide extract of R. griseocarnosa sporocarp. PRG1-1 was composed of glucose, galactose, mannose, xylose and fructose, in a molar ratio of 66.5:29.2:3.17: 0.663:0.447, respectively. Purified PRG1-1 significantly reduced cell viability, increased the production of lactate dehydrogenase (LDH) and reactive oxygen species (ROS), and enhanced the apoptotic rate in HeLa and SiHa cells. Furthermore, after 24h of PRG1-1 exposure the expression levels of cleaved PARP and caspase-3 were increased and mitochondrial cytochrome c was induced to release to the cytosol. Collectively, our results suggested that the cytotoxicity effects of PRG1-1 on human cervical carcinoma are associated with the apoptotic pathway. These data indicate the promising potential of bioactive PRG1-1 as natural agent to inhibit tumor cell proliferation in the treatment of cervical carcinoma.