An inulin-type fructan isolated from Serratula chinensis alleviated the dextran sulfate sodium-induced colitis in mice through regulation of intestinal barrier and gut microbiota

Areca nut polysaccharide induces M1 macrophage polarization through the NF-κB and MAPK pathways independent of TLR2 and TLR4 signaling

In this study, the structure of Areca nut polysaccharide (ANP) was characterized, and its effects on macrophage activation and the underlying molecular mechanisms were investigated. ANP was identified as a glucan with a molecular weight of 24.5 kDa, and its structure was analyzed using XRD, SEM, FT-IR, methylation, and NMR techniques. The main chain of ANP is composed of →4)-α-D-Glcp-(1 → and →4,6)-α-D-Glcp-(1→, with a branched α-D-Glcp-(1 → chain. Furthermore, the activation of macrophages by ANP was explored. Stimulation of RAW264.7 cells with ANP in vitro increased the expression of inflammatory cytokines (TNF-α and IL-6) and NO levels. Flow cytometry showed that ANP induced M1 macrophage polarization. RNA-seq and Western blot analyses revealed that ANP activated the NF-κB and MAPK pathways. Importantly, TLR2- and TLR4- specific antibodies did not affect ANP-induced M1 polarization, whereas endocytosis inhibitors reduced the production of inflammatory cytokines in ANP-treated macrophages. In conclusion, ANP engages macrophages without interacting with TLR2 and TLR4 receptors, inducing M1 polarization through the NF-κB and MAPK signaling pathways.

A ginseng polysaccharide protects intestinal barrier integrity in high-fat diet-fed obese mice

A novel polysaccharide, GPH1, was extracted and isolated from ginseng. Structural analysis of GPH1 revealed a molecular weight of 7.321 × 105 Da and the presence of glucose and galactose components in a 30.2: 1 molar ratio. Results of methylation and NMR analyses indicated the GPH1 backbone consisted of →1)-α-Glc-(3→ and →1)-α-Glc-(6→. The anti-obesity activity of GPH1 was assessed by HFD-induced obesity mouse model. GPH1 was found to significantly reduced body weight, alleviated liver lipid accumulation and inflammatory damage. Meanwhile, GPH1 treatment increased the expression of tight junction proteins, including zonula occludens-1 (ZO-1) and claudin-1, while also regulating the intestinal microbiota of obese mice by promoting proliferation of beneficial bacteria with known anti-obesity effects, including s_Akkermansia muciniphila, s_Lactobacillus intestinalis, s_Lactobacillus reuteri, s_Streptococcus hyointestinalis, and s_Lactococcus garvieae. Our findings demonstrated that GPH1 is a practical natural dietary supplement with potential therapeutic effects on obesity.

Structural characteristics of a polysaccharide from Armillariella tabescens and its protective effect on colitis mice via regulating gut microbiota and intestinal barrier function

A new polysaccharide fraction (ATP) was obtained from Armillariella tabescens mycelium. Structural analysis suggested that the backbone of ATP was →4)-α-D-Glcp(1 → 2)-α-D-Galp(1 → 2)-α-D-Glcp(1 → 4)-α-D-Glcp(1→, which branched at O-3 of →2)-α-D-Glcp(1 → and terminated with T-α-D-Glcp or T-α-D-Manp. Besides, ATP significantly alleviated ulcerative colitis (UC) symptoms and inhibited the production of pro-inflammation cytokines (IL-1β, IL-6). Meanwhile, ATP could improve colon tissue damage by elevating the expression of MUC2 and tight junction proteins (ZO-1, occludin and claudin-1) levels and enhance intestinal barrier function through inhibiting the activation of MMP12/MLCK/p-MLC2 signaling pathway. Further studies exhibited that ATP could increase the relative abundance of beneficial bacteria such as f. Muribaculacese, g. Muribaculaceae, and g. Alistips, and decrease the relative abundance of g. Desulfovibrio, g. Colidextribacter, g. Ruminococcaceae and g.Oscillibacter, and regulate the level of short-chain fatty acids. Importantly, FMT intervention with ATP-derived microbiome certified that gut microbiota was involved in the protective effects of ATP on UC. The results indicated that ATP was potential to be further developed into promising therapeutic agent for UC.

An inulin-type polysaccharide from Atractylodis Macrocephalae Rhizoma can relieve psoriasis

Atractylodis Macrocephalae Rhizoma (AMR), an herb often found in compounded remedies for psoriasis, is rich in polysaccharides. However, the beneficial effects of AMR polysaccharides on psoriasis remain obscure. In this study, an inulin-type fructan-labelled AMP was extracted from the AMR. AMP has a molecular weight of 5.84 kDa and comprises fructose, glucose, and arabinose at a molar ratio of 93:5:2. Methylation and NMR analyses revealed that AMP comprises a linear backbone of 2,6-linked Fruf or 1,2-linked Fruf with branching 1,2,6-linked Fruf and terminates in T-Glcp. Animal studies verified that AMP can improve imiquimod-induced psoriasis-like skin lesions and downregulate the Il-17a, Il-23, Il-22, Il-6, Il-12, and Tnf-α gene expression. Furthermore, we elucidated the underlying mechanisms using cellular experiments. The ability of AMP to inhibit hyperproliferation and the overexpression of TNF-α, IL-6, and IL-23 genes in human immortal keratinocyte cells (HaCaT) stimulated by lipopolysaccharide was demonstrated. These results indicate that AMP may directly target keratinocytes to suppress excessive proliferation and contribute to anti-inflammatory responses, potentially by blocking the activation of the PI3K/AKT/mTOR pathway. In summary, AMP has demonstrated potential as a prospective treatment strategy for psoriasis.

Interplay between traditional Chinese medicine polysaccharides and gut microbiota: The elusive "polysaccharides-bond-bacteria-enzyme" equation

Polysaccharides are one of the most important components of traditional Chinese medicine (TCM) and have been extensively studied for their immunomodulatory properties. The functions and effects of TCM polysaccharides are closely related to the gut microbiota, making the study of their interaction a hot topic in the field of TCM metabolism. This review follows two main inquiries: first, how the gut microbiota breaks down TCM polysaccharides to produce bioactive metabolites; and second, how TCM polysaccharides reshape the gut microbiota as a carbon source. Understanding the interaction mechanism involves a challenging equation of the structural association of TCM polysaccharides with the metabolic activities of the microbiota. This review has meticulously searched, partially organized literature spanning the past decade, that delves into the interaction mechanism between TCM polysaccharides and gut microbiota. It also gives an overview of the complex factors of the elusive "polysaccharides-bond-bacteria-enzyme" equation: the complexity of polysaccharide structures, the diversity of glycosidic bond types, the communal nature of metabolizing microbiota, the enzymes involved in functional degradation by microbiota, and the hierarchical roles of polysaccharide utilization locus and gram-positive PULs. Finally, this review aims to facilitate discussion among peers in the field of TCM microbiota and offers prospects for research in related fields, paving the way for pharmacological studies on TCM polysaccharides and gut microbiota therapeutics, and providing a reference point for further clinical research.

Abelmoschus manihot polysaccharide fortifies intestinal mucus barrier to alleviate intestinal inflammation by modulating Akkermansia muciniphila abundance

The intestinal mucus barrier is an important line of defense against gut pathogens. Damage to this barrier brings bacteria into close contact with the epithelium, leading to intestinal inflammation. Therefore, its restoration is a promising strategy for alleviating intestinal inflammation. This study showed that Abelmoschus manihot polysaccharide (AMP) fortifies the intestinal mucus barrier by increasing mucus production, which plays a crucial role in the AMP-mediated amelioration of colitis. IL-10-deficient mouse models demonstrated that the effect of AMP on mucus production is dependent on IL-10. Moreover, bacterial depletion and replenishment confirmed that the effects of AMP on IL-10 secretion and mucus production were mediated by Akkermansia muciniphila. These findings suggest that plant polysaccharides fortify the intestinal mucus barrier by maintaining homeostasis in the gut microbiota. This demonstrates that targeting mucus barrier is a promising strategy for treating intestinal inflammation.

Structural characterization of extracellular polysaccharides from Phellinus igniarius SH-1 and their therapeutic effects on DSS induced colitis in mice

Phellinus igniarius is a valuable medicinal and edible mushroom, and its polysaccharides exhibit excellent anti-inflammatory activity. During liquid fermentation to produce P. igniarius mycelia, the fermentation liquid is often discarded, but it contains extracellular polysaccharides. To better utilize these resources, P. igniarius SH-1 was fermented in a 100 L fermenter, and PIPS-2 was isolated and purified from the fermentation broth. The structural characteristics and anti-inflammatory activity of PIPS-2 were determined. PIPS-2 had a molecular weight of 22.855 kDa and was composed of galactose and mannose in a molar ratio of 0.38:0.62. Structural analysis revealed that the main chain of PIPS-2 involved →2)-α-D-Manp-(1 → 3)-β-D-Galf-(1→, and the side chains involved α-D-Manp-(1 → 6)-α-D-Manp-(1→, α-D-Manp-(1 → 3)-α-D-Manp-(1→, and α-D-Manp-(1. PIPS-2 alleviated the symptoms of dextran sodium sulfate (DSS)-induced colitis in mice, improved the imbalance of inflammatory factors and antioxidant enzymes, and increased short-chain fatty acid contents. Combining the intestinal flora and metabolite results, PIPS-2 was found to regulate the abundance of Firmicutes, Lachnospiraceae_NK4A136_group, Proteobacteria, Bacteroides, and many serum metabolites including hexadecenal, copalic acid, 8-hydroxyeicosatetraenoic acid, artepillin C, and uric acid, thereby ameliorating metabolite related disorders in mice with colitis. In summary, PIPS-2 may improve colitis in mice by regulating the gut microbiota and metabolites.

Rosa laevigata Polysaccharides Ameliorate Dextran Sulfate Sodium-Induced Ulcerative Colitis of Beagles through Regulating Gut Microbiota

Rosa laevigata Michx. polysaccharides (RLP) have been demonstrated to possess antioxidant and anti-inflammatory properties. However, the mechanisms and efficacy of these polysaccharide components in preventing ulcerative colitis (UC) remain to be elucidated. The efficacy and mechanisms of RLP were investigated in a study that utilized healthy adult beagles to establish a UC model, considering the similarities in gut microbiota between humans and dogs. In the study, the beagle model induced by sodium dextran sulfate exhibited typical symptoms of ulcerative colitis, such as weight loss and diarrhea. All these symptoms and changes were significantly ameliorated through oral supplementation of RLP. Additionally, microbial community analysis based on the 16S rDNA gene revealed that RLP alleviated UC by increasing the abundance of beneficial bacteria and reducing the abundance of harmful bacteria. In conclusion, our study has provided that RLP effectively alleviated colitis by preserving the intestinal barrier and regulating the gut microbiota composition.

Magnolia Officinalis Alcohol Extract Alleviates the Intestinal Injury Induced by Polygala Tenuifolia Through Regulating the PI3K/AKT/NF-κB Signaling Pathway and Intestinal Flora

Purpose

Polygala tenuifolia Willd. (PT), a traditional Chinese medicinal plant extensively employed in managing Alzheimer's disease, exhibits notable gastrointestinal side effects as highlighted by prior investigations. In contrast, Magnolia officinalis Rehd. et Wils (MO), a traditional remedy for gastrointestinal ailments, shows promising potential for ameliorating this adverse effect of PT. The objective of this study is to examine the underlying mechanism of MO in alleviating the side effects of PT.

Methods

Hematoxylin-eosin (H&E) staining was used to observe the structural damage of zebrafish intestine, and enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of inflammatory factors and oxidative stress. The integrity of the intestinal tight junctions was examined using transmission electron microscope (TEM). Moreover, the expression of intestinal barrier genes and PI3K/AKT/NF-κB signaling pathway-related genes was determined through quantitative real-time PCR. The changes in intestinal microbial composition were analyzed using 16S rRNA and metagenomic techniques.

Results

MO effectively ameliorated intestinal pathological damage and barrier gene expression, and significantly alleviated intestinal injury by reducing the expression of inflammatory cytokines IL-1β, IL-6, TNF-α, and inhibiting the activation of PI3K/AKT/NF-κB pathway. Furthermore, MO could significantly increase the relative abundance of beneficial microorganisms (Lactobacillus, Blautia and Saccharomyces cerevisiae), and reduce the relative abundance of pathogenic bacteria (Plesiomonas and Aeromonas).

Conclusion

MO alleviated PT-induced intestinal injury, and its mechanism may be related to the inhibition of PI3K/AKT/NF-κB pathway activation and regulation of intestinal flora.

Dietary supplementation with inulin improves burn-induced skeletal muscle atrophy by regulating gut microbiota disorders

Inulin, as a prebiotic, could modulate the gut microbiota. Burn injury leads to gut microbiota disorders and skeletal muscle catabolism. Therefore, whether inulin can improve burn-induced muscle atrophy by regulating microbiota disorders remains unknown. This study aimed to clarify that inulin intake alleviates gut microbiota disorders and skeletal muscle atrophy in burned rats. Rats were divided into the sham group, burn group, prebiotic inulin intervention group, and pseudo-aseptic validation group. A 30% total body surface area (TBSA) third-degree burn wound on dorsal skin was evaluated in all groups except the sham group. Animals in the intervention group received 7 g/L inulin. Animals in the validation group received antibiotic cocktail and inulin treatment. In our study inulin intervention could significantly alleviate the burn-induced skeletal muscle mass decrease and skeletal myoblast cell apoptosis. Inulin intake increased the abundances of Firmicutes and Actinobacteria but decreased the abundance of Proteobacteria. The biosynthesis of amino acids was the most meaningful metabolic pathway distinguishing the inulin intervention group from the burn group, and further mechanistic studies have shown that inulin can promote the phosphorylation of the myogenesis-related proteins PI3K, AKT and P70S6K and activate PI3K/AKT signaling for protein synthesis. In conclusion, inulin alleviated burn induced muscle atrophy through PI3K/AKT signaling and regulated gut microbiota dysbiosis.