Three anti-inflammatory polysaccharides from <i>Lonicera japonica</i> Thunb.: insights into the structure-function relationships

Abstract

This study demonstrates the feasibility of producing three polysaccharides (neutral LJP-1, acidic LJP-2 and acidic LJP-3) with significant <em>in vitro</em> and <em>in vivo</em> anti-inflammatory activities from the flowers of <em>Lonicera japonica</em>. The three polysaccharides differed in chemical composition, Mw distribution, glycosidic linkage pattern, functional groups and morphology. They exhibited excellent protective effects (in a dose-dependent manner) in lipopolysaccharide-injured RAW264.7 macrophages and CuSO₄-damaged zebrafish via reducing NO production and inhibiting the overexpressions of inflammation-related transcription factors, inflammatory proteins and cytokines in the NF-<em>κ</em>B/MAPK signaling pathways. Their anti-inflammatory effects varied owing to their different molecular characteristics and chemical compositions. Overall, LJP-2 at 400 μg/mL was the most effective. LJP-2 consisted mainly of →5)-<em>α</em>-L-Ara<em>f</em> (1→, →4)-<em>α</em>-L-Gal<em>p</em>A (1→ and →2)-<em>α</em>-L-Rha<em>p</em> (1→ residues with terminal T-<em>β</em>-D-Glc<em>p</em>. Thus, honeysuckle flowers are good sources of anti-inflammatory polysaccharides, and precise fractionation enables the production of potent anti-inflammatory agents for the development of functional foods and healthcare products.