title: A novel polysaccharide isolated from Litchi chinensis by using a simulated gastric medium and its immunomodulatory activity.
abstract: A novel polysaccharide (LCPA50-S1) with immunomodulatory activity was extracted with simulated gastric medium from Litchi chinensis, and purified by DEAE-52 cellulose column, Sephadex G-50 column and Sephacryl S-300 HR chromatography. The structural characteristics of LCPA50-S1 were expounded through complete acid hydrolysis, partial acid hydrolysis, methylation and instrumental analysis. The results demonstrated that LCPA50-S1 is a heteropolysaccharide with a molecular weight of 1.58 × 10(5) Da. The backbone was composed of (1→4)-linked β-D-glucopyranosyl residues, (1→6)-linked β-D-galactopyranosyl, (1→3,6)-linked β-D-galactopyranosyl residues, (1→4,6)-linked α-D-glucopyranosyl residues and branched at O-6. The branches were consisted of (1→2)-linked α-L-rhamnopyranosyl residues, (1→4)-linked β-D-glucopyranosyl residues, and (1→6)-linked β-D-galactopyranosyl, terminated with (1→)-linked α-L-arabinopyranosyl residues and (1→)-linked β-D-galactopyranosyl residues, respectively. The immunoregulatory activity of LCPA50-S1 was evaluated through determination the effect of LCPA50-S1 on nitric oxide (NO) production of RAW264.7 macrophages and spleen lymphocyte proliferation as well as its cytokines secretion level. The results demonstrated that LCPA50-S1 increased NO and TNF-α production in RAW264.7 macrophages significantly, enhanced the proliferation as well as the interleukin-2 (IL-2) production of splenocytes. The data indicated that LCPA50-S1 had the potential to be explored as a novel natural immunomodulator for application in functional foods and medicine.
authors.affiliation: Biotechnological Institute of Chinese Materia Medica, Jinan University.
authors.forename: Lishan
authors.initials: L
authors.lastname: Wang
authors.forename: Xianjing
authors.initials: X
authors.lastname: Hu
authors.forename: Sixue
authors.initials: S
authors.lastname: Bi
authors.forename: Wensong
authors.initials: W
authors.lastname: Tu
authors.forename: Yongshuai
authors.initials: Y
authors.lastname: Jing
authors.forename: Liyan
authors.initials: L
authors.lastname: Song
authors.forename: Wenjie
authors.initials: W
authors.lastname: Lv
authors.forename: Rongmin
authors.initials: R
authors.lastname: Yu
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D008401:Gas Chromatography-Mass Spectrometry; D032125:Litchi / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D051379:Mice; D008970:Molecular Weight; D011134:Polysaccharides / Q000032:analysis / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D000276:Adjuvants, Immunologic; D011134:Polysaccharides