The structures of two acidic polysaccharides from Gardenia jasminoides and their potential immunomodulatory activities

Abstract

This study identified two homogeneous acidic polysaccharides from Gardeniae fructus, GJP50–3 and GJP50–4, which exhibited potential immunomodulatory activities in macrophage activation assays, via liquid-chip technology, and in a zebrafish model. Monosaccharide composition analysis and gel permeation chromatography revealed that GJP50–3 and GJP50–4 were composed of Rha, GalA, Glc, Gal, and Ara in specific ratios and had molecular weights of 91.5 kDa and 140.3 kDa, respectively. Based on FT-IR, GC–MS, and NMR analyses, these polysaccharides were identified as typical pectin polysaccharides with methylation degrees of 24.7 % and 21.4 %, respectively. The primary structures of GJP50–3 and GJP50–4 included linear HG domains and branched RG-I domains with arabinans and AG side chains. In vitro, GJP50–3 and GJP50–4 could stimulate NO release and increase the secretion of TNF-α in a RAW 264.7 macrophage model. Luminex liquid suspension chip detection revealed that GJP50–3 significantly promoted the secretion of multiple interleukins [IL-6, IL-9, IL-10, IL-12 (p40), IL-12 (p70), IL-13], TNF-α, and chemokines (G-CSF, GM-CSF, MCP-1 and RANTES). In vivo, these polysaccharides could also increase NO release and neutrophil count in a zebrafish model. These findings suggested that GJP50–3 and GJP50–4 might have the potential to be used as immunomodulators in the food and pharmaceutical industries.