A branched galactoglucan from Lysimachia christinae: Structural characterization, immunoregulatory and anti-oxidant bioactivities in vitro and in vivo

Lysimachia christinae , revered as a traditional tea plant in China, is notable for diverse biological activities. However, a comprehensive characterization of its polysaccharides and their biological activities has been largely unexplored. Herein, a galactoglucan was extracted and purified from L. christinae to assess its immunoregulatory and anti-oxidant activities both in vitro and in vivo . The crude polysaccharide was extracted via hot water extraction, ethanol precipitation, and Sevage deproteinization, followed by purification using AB-8, DEAE-52, and Superdex G-200 chromatography to obtain the polysaccharide, namely LCNP. GC–MS and NMR analyses confirmed that LCNP was primarily composed of →4)-Glcp-(1→, accounting for 49.1 % of its structure. In vitro experiments demonstrated that LCNP possesses anti-inflammatory effects, mainly protects L02 and HepA cells from lithocholic acid-induced damage by increasing SOD and GSH contents, protects Caco-2 cells from apoptosis, reduces the production of NO and inflammatory cytokines in macrophages. Furthermore, LCNP stimulated the proliferation of lymphocytes, concurrently leading to upregulating the generation of IL-10 and CD4 + /CD8 + ratio in lymphocytes. In mouse, oral administration of LCNP protected the liver and intestines, reduced inflammatory mediators LPS, IL-1β, and IFN-γ, increased the content of IL-10, SOD, CAT, and GSH, and upregulated the CD4 + /CD8 + ratio. Collectively, this study has successfully isolated and characterized a branched galactoglucan from L. christinae , and verified LCNP could protect hepatic cells and reduce the production of inflammatory mediators in macrophages in vitro . Oral administration of LCNP reduced inflammatory mediators and increased the content of IL-10, making it a candidate for practical applications.