Structural characteristics and anti-tumor activity of alkali-extracted acidic polysaccharide extracted from Panax ginseng

In this paper, Panax ginseng residue after boiling water extraction was reused to obtain the acidic polysaccharide PGP-1, and its structural characterization and anti-tumor activity were investigated. Structural experiments showed that PGP-1 consisted of Rha, Ara, Glc, Gal, and GalA in a molar ratio of 0.04:0.31:1.00:0.28:0.54. The backbone of PGP-1 was formed by the 1 -> 4 glycosidic linkage of HG and RG-I, with Araf, Glcp, and Galp sidechains attached at position O-3. In vitro experiments showed that PGP-1 induced apoptosis in MGC803 cells through the mitochondrial pathway, with apoptotic features such as nuclear consolidation and generation of apoptotic vesicles. Animal experiments showed that PGP-1 could inhibit the proliferation of tumor cells in H22 tumor-bearing mice by improving the status of immune organs, enhancing the activity of immune cells, and increasing the levels of serum cytokines and apoptosis-related proteins, with the tumor inhibition rate reaching 45.70 % (200 mg/kg). The above experimental results indicated that Panax ginseng polysaccharides had the potential to be functional anti-tumor agents.