Mechanism regulating the inhibition of lung cancer A549 cell proliferation and structural analysis of the polysaccharide Lycium barbarum

The water-soluble polysaccharide LBP-1 was isolated and characterized from Lycium barbarum L.LBP-1 was mainly composed of arabinose,galactose,glucose,xylose,mannose at a molar ratio of 37.53:28.08:14.72:7.83:4.50,respectively.Based on nuclear magnetic resonance(NMR)and methylation analysis,the backbone of LBP-1 was speculated in theα-L-Ara(1→[5-α-L-Ara(1→3)-β-D-Galp-(1→]n→4)-α-D-Galp-(1[→5-α-L-Ara(1]n[→6)-β-D-Galp-(1→4)-β-D-Galp-(1→]n,and the side chains of LBP-1 were in theα-L-Ara(1→3)-β-D-Galp-(1→6 position.These results showed that LBP-1 inhibited the growth of cancer A549 cells through cell cycle arrest and apoptosis,with an IC50 value of 42.5μg/mL.In addition,LBP-1 altered the expression of Cyclin D1,Cyclin D3,and CDK 2,thus blocking the cell cycle in G0/G1 phase,reducing cell migration,and regulating the PI3K/Akt/mTOR signaling pathway to induce apoptosis.