Anti-cancer Potential of Polysaccharide Extracted From Polygonatum sibiricum on HepG2 Cells via Cell Cycle Arrest and Apoptosis

Abstract

<i>Polygonatum sibiricum</i> is one of the most widely used traditional Chinese medicine in China. <i>Polygonatum sibiricum</i> polysaccharide (PSP) is the main functional component of <i>Polygonatum sibiricum</i>. In this study, a water-soluble polysaccharide (PSP-1) was first isolated from <i>Polygonatum sibiricum</i> with a molecular weight of 38.65 kDa. Structural analysis was performed via methylation and FT-IR spectroscopy analyses, which in combination with NMR spectroscopy, revealed that PSP-1 has a → 4-α-D-Glcp-1 → backbone with the substitution at O-6 with the β-D-Glcp-1 → residues. Furthermore, PSP-1 exhibited potent and concentration-dependent anticancer effects, inducing HepG2 cell apoptosis and arresting the cell cycle at the G1 phase. Moreover, PSP-1 also decreased the mitochondrial membrane potential, damaged the nucleus of HepG2 cells, and increased the activity of caspase-9 and-3 in the intrinsic apoptotic pathways to induce HepG2 cell apoptosis. To conclude, PSP-1 might be a good candidate for the treatment of liver cancer, and this work provides important information for understanding the relationship between structure and antitumor activity of PSP-1, which is relevant for the treatment of hepatocellular carcinoma in clinic.