A heteropolysaccharide purified from leaves of Ilex latifolia displaying immunomodulatory activity in vitro and in vivo

Abstract

A novel polysaccharide (ILP50-2) was extracted, isolated and purified from the leaves of Ilex latifolia Thunb. Its structure was characterized as a repeating unit consisting of α-L-Araf-(1→, →3)-α-L-Araf-(1→, →5)-α-L-Araf-(1→, →3,5)-α-L-Araf-(1→, →2)-α-L-Rhap-(1→, →2,4)-α-L-Rhap-(1→, β-D-Galp-(1→, →4)-β-D-Galp-(1→, →4)-β-D-Glcp-(1→, →6)-α-D-Manp-(1→, and →3,6)-α-D-Galp-(1→. The absolute molecular weight of ILP50-2 was 1.49 × 10⁵ g/mol, which adapted a compact coil conformation in 0.1 M NaCl solution with R_z of 25.4 nm. Furthermore, ILP50-2 exhibited immunoregulatory activity, mainly through enhancing the phagocytosis ability of macrophages and prompting the release of nitric oxide (NO) and cytokines tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β). Simultaneously, ILP50-2 was found to significantly increase the release of ROS and NO in zebrafish embryos, showing immunoregulatory effects in vivo.

Keywords: Chloroform (PubChem CID: 6212); D-Galactose (PubChem CID: 6036); D-Glucose (PubChem CID: 5793); D-Mannose (PubChem CID: 18950); Dimethyl sulfoxide (PubChem CID: 679); Ilex latifolia; Immunoregulatory activity; L-Arabinose (PubChem CID: 439195); Methyl iodide (PubChem CID: 6328); Neutral red (PubChem CID: 11105); Polysaccharide; Thiazolyl Blue Tetrazolium Bromide (PubChem CID: 64965); Trifluoroacetic acid (PubChem CID: 6422); Zebrafish.