Physicochemical characterization and antitumor activity in vitro of a polysaccharide from Christia vespertilionis

CVP-2 is a homogeneous polysaccharide extracted from the whole plant of Christia vespertilionis, with an average molecular weight of approximately 92,920 Da. Its main chain consists of repeating units of [3,5)-α-L-Araf-(1]₂ → [5)-α-L-Araf-(1]₂→, with branches at the C-3 position: branch 1 is α-L-Araf-(1→, and branch 2 is α-L-Araf-(1 → 4)-. Additionally, the structure includes β-D-Gclp-(1 → [4)-β-D-Glap-(1]₂ → 5)-α-L-Araf-(1→. In vitro experiments conducted on cancer and normal cell lines demonstrated that the purified polysaccharide exhibited a significant pro-apoptotic effect on lung and liver cancer cells, while having no impact on the growth of normal tissue cells at dosage concentrations ranging from 125 to 1000 μg/mL. The inhibition of cell viability at 1000 μg/mL CVP-2 was 49.63 % for A549, 2.6 % for 16HBE, 28.56 % for HepG2, and 12.64 % for LX-2. Compared to the drug-free group, the death rates of A549, 16HBE, HepG2, and LX-2 cells increased by 37.13 %, 4.15 %, 26.00 %, and 4.41 %, respectively. CVP-2 was found to inhibit the G1/S phase of the cell cycle. The potential anticancer mechanism of CVP-2 involves a reduction in the Bcl-2/Bax protein in cancer cells, with no significant effect on the growth of normal cells. Therefore, CVP-2 holds great promise as a broad-spectrum antitumor agent and dietary supplement.