Structural characterization and anti-proliferative activities of partially degraded polysaccharides from peach gum

Abstract

<p class="first" id="d2458666e166">LP100R, LP10R and LP5R were isolated from peach gum by ultrafiltration. They were identified as AG II arabinogalactans composed of mannose, rhamnose, glucuronic acid, galactose, xylose and arabinose, which had a β-d-(1→6)-galactan backbone and were branched at O-3 and O-4. LP100R, LP10R and LP5R exist in a spherical conformation with the molecular weight of 8.50 × 104 g/mol, 4.77 × 104 g/mol and 2.40 × 104 g/mol, respectively. The binding affinities of LP fractions to galectin-3 (Gal-3) were 0.77 μM for LP100R, 2.88 μM for LP10R and 5.15 μM for LP5R, respectively. Meanwhile, an anti-proliferative assay revealed that LP100R possessed higher anti-proliferative activity against HepG2 cells (IC50, 4.5 mg/mL) and MCF-7 cells (IC50, 0.43 mg/mL) than did LP10R and LP5R, which were in accordance with their binding affinities to galectin-3. Therefore, LP fractions (especially LP100R) might exert the anti-tumor activity by directly inhibiting the Gal-3 mediated proliferation of cancer cells. </p>