Elucidation of the microstructure of an immuno-stimulatory polysaccharide purified from Korean red ginseng using sequential hydrolysis

Effect of rhamnogalacturonan-I-rich polysaccharides isolated from crabapple hydrolysates on IL-1β-induced inflammation in intestinal epithelial cells

This study aimed to investigate the structural characteristics and intracellular mechanisms of polysaccharides (MP-PE-I) purified from a crabapple (Malus prunifolia) enzymatic hydrolysate (MP-PE). Activity-guided fractionation revealed that MP-PE-I was the active moiety and significantly reduced the production and gene expression of pro-inflammatory factors in interleukin (IL)-1β-treated intestinal epithelial cells (Caco-2). Moreover, MP-PE-I downregulated the phosphorylation and nuclear localization of proteins involved in the mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) pathways, as evidenced by immunoblotting and immunofluorescence analysis. In antagonistic studies with specific inhibitors of the MAPK and NF-κB pathways, IL-6 inhibition was significantly regulated by p38; IL-8 by IκBα, JNK, and p38; and monocyte chemoattractant protein-1 (MCP-1) by JNK, p38, and ERK. Additionally, MP-PE-I significantly decreased the mRNA and protein expression of IL-1 receptor type 1. Chemical and structural characteristic analyses showed that MP-PE-I is a polysaccharide rich in rhamnogalacturonan (RG)-I and plays a crucial role in intestinal immunomodulation. To our knowledge, this is the first study to demonstrate the intestinal immunomodulatory activity, intracellular mechanisms, and structural characteristics of RG-I-rich polysaccharides isolated from crabapples.

Recent trends in ginseng research

Ginseng, the dried root of Panax ginseng, contains ginsenosides and has long been used in Korea, China, and Japan to treat various symptoms. Many studies on the utility of ginseng have been conducted and in this paper we investigate recent trends in ginseng research. P. ginseng studies were collected from scientific databases (PubMed, Web of Science, and SciFindern) using the keywords "Panax ginseng C.A. Meyer", "ginsenosides", "genetic diversity", "biosynthesis", "cultivation", and "pharmacology". We identified 1208 studies up to and including September 2023: 549 studies on pharmacology, 262 studies on chemical components, 131 studies on molecular biology, 58 studies on cultivation, 71 studies on tissue culture, 28 studies on clinical trials, 123 reviews, and 49 studies in other fields. Many researchers focused on the characteristic ginseng component ginsenoside to elucidate the mechanism of ginseng's pharmacological action, the relationship between component patterns and cultivation areas and conditions, and gene expression.

Analysis of pectin-cellulose interaction in cell wall of lotus rhizome with assistance of ball-milling and galactosidase

The current study sought to depict the structural feature of polysaccharides extracted from Na2CO3 unextractable fraction (LUN) of lotus rhizome using galactosidase with assistance of ball milling. The extracted polysaccharides were a complex of cellulose microfibrils and the RG-I structural domain of pectin, and the top three monosaccharides were glucose, galactose and galactose uronic acid, which allowed to tune the properties of the enzyme-hydrolyzed polysaccharide from LUN after 15 and 45 min of ball milling. The data of XRD revealed that pectin has a masking effect on the diffraction peaks of cellulose components. The removing of the polysaccharides could increase the degree of crystallinity and the pectin-cellulose interaction mainly occured through the galactan side chain was speculated. Textural characterization by SEM exhibited a cross-linked rod-like structure, which is similar to the structure of cellulose microfibrils. The morphological analysis of AFM revealed that L15-P (enzyme-hydrolyzed polysaccharide from LUN after 15 min of ball milling) contained relatively ordered and uniform network structures. Overall, the present study provides an important insight into cell wall of lotus rhizome matrix polysaccharide.

Clarification of the structural features of Rhamnogalacturonan-I type polysaccharide purified from radish leaves

Determining the structure of REPI, an immunostimulatory polysaccharide fraction from radish leaves, is an important health objective. Herein, we show that REP-I contains nine different monosaccharides, including GalA (22.2%), Gal (32.6%), Ara (27.5%), and Rha (10.2%) as main sugars. REP-I was also reacted with β-glucosyl Yariv reagent (29.8%), suggesting the presence of the arabino-β-3,6-galactan. Furthermore, methylated-product analysis revealed that REP-I contains 13 different glycosyl linkages, including 4-linked GalpA (21.0%), 2,4-linked Rhap (7.0%), 4-linked Galp (5.8%), 5-linked Araf (10.1%), and 3,6-linked Galp (7.9%), which are characteristic of RG-I. Microstructural information was obtained by sequential degradation using four linkage-specific glycosylases and β-elimination, with fragments analyzed on the basis of sugar composition, methylation, and MS/MS spectra. The results show that the immunostimulatory activity of REP-I is possibly due to the structure of RG-I, which is composed of a main chain with repeating [→2)-Rhap-(1 → 4)-GalpA-(1→] linkage units and three side-chains: a branched α(1 → 5)arabinan, a β(1 → 4)galactan, and arabino-β-3,6-galactan, which are branched at the C(O)4 position of each Rha residue in the REP-I main chain.