Dendrobium fimbriatum polysaccharide ameliorates DSS-induced intestinal mucosal injury by IL-22-regulated intestinal stem cell regeneration

Research progress in the treatment of inflammatory bowel disease with natural polysaccharides and related structure-activity relationships

Inflammatory bowel disease (IBD) comprises a group of highly prevalent and chronic inflammatory intestinal tract diseases caused by multiple factors. Despite extensive research into the causes of the disease, IBD's pathogenic mechanisms remain unclear. Moreover, side effects of current IBD therapies restrict their long-term clinical use. In contrast, natural polysaccharides exert beneficial anti-IBD effects and offer advantages over current anti-IBD drugs, including enhanced safety and straightforward isolation from abundant and reliable sources, and thus may serve as components of functional foods and health products for use in IBD prevention and treatment. However, few reviews have explored natural polysaccharides with anti-IBD activities or the relationship between polysaccharide conformation and anti-IBD biological activity. Therefore, this review aims to summarize anti-IBD activities and potential clinical applications of polysaccharides isolated from plant, animal, microorganismal, and algal sources, while also exploring the relationship between polysaccharide conformation and anti-IBD bioactivity for the first time. Furthermore, potential mechanisms underlying polysaccharide anti-IBD effects are summarized, including intestinal microbiota modulation, intestinal inflammation alleviation, and intestinal barrier protection from IBD-induced damage. Ultimately, this review provides a theoretical foundation and valuable insights to guide the development of natural polysaccharide-containing functional foods and nutraceuticals for use as dietary IBD therapies.

Qingzhuan dark tea polysaccharides-zinc alleviates dextran sodium sulfate-induced ulcerative colitis

BACKGROUND

Qingzhuan dark tea polysaccharides (QDTP) have been complexed with Zinc (Zn) to form the Qingzhuan dark tea polysaccharides-Zinc (QDTP-Zn) complex. The present study investigated the protective effects of QDTP-Zn on ulcerative colitis (UC) in mice. The UC mouse model was induced using dextran sodium sulfate (DSS), followed by oral administration of QDTP-Zn (0.2 and 0.4 g kg-1 day-1).

RESULTS

QDTP-Zn demonstrated alleviation of UC symptoms in mice, as evidenced by a decrease in disease activity index scores. QDTP-Zn also regulated colon tissue injury by upregulating ZO-1 and occludin protein expression, at the same time as downregulating tumor necrosis factor-α and interleukin-6β levels. Furthermore, QDTP-Zn induced significant alterations in the abundance of bacteroidetes and firmicutes and notably increased levels of short-chain fatty acids (SCFAs), particularly acetic acid, propionic acid, and butyric acid.

CONCLUSION

In summary, QDTP-Zn exhibits therapeutic potential in alleviating enteritis by fortifying the colonic mucosal barrier, mitigating inflammation and modulating intestinal microbiota and SCFAs levels. Thus, QDTP-Zn holds promise as a functional food for both the prevention and treatment of UC. © 2024 Society of Chemical Industry.

Sedanolide alleviates DSS-induced colitis by modulating the intestinal FXR-SMPD3 pathway in mice

INTRODUCTION

Inflammatory bowel disease (IBD) is a global disease with limited therapy. It is reported that sedanolide exerts anti-oxidative and anti-inflammatory effects as a natural phthalide, but its effects on IBD remain unclear.

OBJECTIVES

In this study, we investigated the impacts of sedanolide on dextran sodium sulfate (DSS)-induced colitis in mice.

METHODS

The mice were administered sedanolide or vehicle followed by DSS administration, after which colitis symptoms, inflammation levels, and intestinal barrier function were evaluated. Transcriptome analysis, 16S rRNA sequencing, and targeted metabolomics analysis of bile acids and lipids were performed.

RESULTS

Sedanolide protected mice from DSS-induced colitis, suppressed the inflammation, restored the weakened epithelial barrier, and modified the gut microbiota by decreasing bile salt hydrolase (BSH)-expressing bacteria. The downregulation of BSH activity by sedanolide increased the ratio of conjugated/unconjugated bile acids (BAs), thereby inhibiting the intestinal farnesoid X receptor (FXR) pathway. The roles of the FXR pathway and gut microbiota were verified using an intestinal FXR-specific agonist (fexaramine) and germ-free mice, respectively. Furthermore, we identified the key effector ceramide, which is regulated by sphingomyelin phosphodiesterase 3 (SMPD3). The protective effects of ceramide (d18:1/16:0) against inflammation and the gut barrier were demonstrated in vitro using the human cell line Caco-2.

CONCLUSION

Sedanolide could reshape the intestinal flora and influence BA composition, thus inhibiting the FXR-SMPD3 pathway to stimulate the synthesis of ceramide, which ultimately alleviated DSS-induced colitis in mice. Overall, our research revealed the protective effects of sedanolide against DSS-induced colitis in mice, which indicated that sedanolide may be a clinical treatment for colitis. Additionally, the key lipid ceramide (d18:1/16:0) was shown to mediate the protective effects of sedanolide, providing new insight into the associations between colitis and lipid metabolites.

Research advancements and perspectives of inflammatory bowel disease: A comprehensive review

Inflammatory bowel disease (IBD) is a chronic inflammatory disease with increasing incidence, such as Crohn's disease and ulcerative colitis. The accurate etiology and pathogenesis of IBD remain unclear, and it is generally believed that it is related to genetic susceptibility, gut microbiota, environmental factors, immunological abnormalities, and potentially other factors. Currently, the mainstream therapeutic drugs are amino salicylic acid agents, corticosteroids, immunomodulators, and biological agents, but the remission rates do not surpass 30-60% of patients in a real-life setting. As a consequence, there are many studies focusing on emerging drugs and bioactive ingredients that have higher efficacy and long-term safety for achieving complete deep healing. This article begins with a review of the latest, systematic, and credible summaries of the pathogenesis of IBD. In addition, we provide a summary of the current treatments and drugs for IBD. Finally, we focus on the therapeutic effects of emerging drugs such as microRNAs and lncRNAs, nanoparticles-mediated drugs and natural products on IBD and their mechanisms of action.

Bletilla striata carbon dots with alleviating effect of DSS-induced ulcerative colitis

Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) that significantly affected quality of life for patients. In this study, carbon dots based on Bletilla striata (BS-CDs) were synthesized by hydrothermal method and characterized by optical property analysis. In addition, the study measured the potential effect of BS-CDs on colonic histopathology and inflammation in dextran sulfate sodium (DSS)-induced ulcerative colitis. The results suggested that BS-CDs significantly increased colon length, improved colonic histopathology, and reduced the levels of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in colitis mice. Taken together, BS-CDs alleviate clinical inflammation by blocking pro-inflammatory cytokines which were expected to be a potential agent for the treatment of colitis.

Portulaca oleracea L. polysaccharide alleviates dextran sulfate sodium-induced ulcerative colitis by regulating intestinal homeostasis

Portulaca oleracea L. (purslane) is a vegetable that contains a variety of active compounds with nutritional properties and has the potential to treat ulcerative colitis (UC). However, the mechanisms underlying the effects of Portulaca oleracea L. polysaccharide (POP) in alleviating UC remain unclear. In this study, we prepared an aqueous extract of purslane and separated a fraction with molecular weight >10 kDa using membrane separation. This fraction was used to isolate POP. The effect of POP on gut microbiota and colon transcriptome in dextran sulfate sodium-induced UC model mice was evaluated. POP treatment reduced inflammation and oxidative stress imbalance in UC mice. In addition, POP improved the intestinal barrier and regulated intestinal homeostasis. Importantly, POP was found to regulate gut microbiota, maintain the levels of retinol and short-chain fatty acids in the gut, promote the proliferation and differentiation of B cells in the colon, and increase the expression of immunoglobulin A. These results provide novel insights into the role of POP in regulating intestinal homeostasis, which should guide further development of POP as a functional food.

A Comparative Analysis of Chemical Constituents and Antioxidant Effects of Dendrobium fimbriatum Hook Fractions with Different Polarities

The aim of this study was to investigate the chemical composition and antioxidant capacity of various polar fractions obtained from Dendrobium fimbriatum Hook (DH). First, a 90% ethanol-aqueous extract of DH (CF) was subjected to sequential fractionation using different organic solvents, resulting in the isolation of a methylene chloride fraction (DF), an ethyl acetate fraction (EF), an n-butanol fraction (BF), and a remaining water fraction (WF) after condensation. Additionally, the CF was also subjected to column chromatography via a D101 macroreticular resin column, eluted with ethanol-aqueous solution to yield six fractions (0%, 20%, 40%, 60%, 80%, and 100%). UPLC-Q-Exactive Orbitrap-MS/MS analysis identified a total of 47 chemical compounds from these polar fractions, including fatty acids, amino acids, phenolic acids, flavonoids, organic heterocyclic molecules, and aromatic compounds. Moreover, DF, EF, and the 60%, 80%, and 100% ethanol-aqueous fractions had higher total phenol content (TPC) and total flavonoid content (TFC) values and greater 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS-) and 1,1-diphenyl-2-picrylhydrazyl (DPPH)-scavenging abilities. In H2O2-induced HepG2 cells, the aforementioned fractions could increase the activities of antioxidative enzymes NAD(P)H: quinone oxidoreductase 1 (NQO1), superoxide dismutase (SOD), heme oxygenase-1 (HO-1) and catalase (CAT), stimulate glutathione (GSH) synthesis by increasing the activities of glutamic acid cysteine ligase (GCL) and glutathione synthetase (GS), regulate GSH metabolism by increasing glutathione peroxidase (GSH-Px) and glutathione reductase (GR) activities, and reduce levels of reactive oxygen species (ROS) and malondialdehyde (MDA). Furthermore, the antioxidative stress effect of the DH fractions was found to be positively correlated with the activation of nuclear factor-erythroid 2-related factor 2 (Nrf2) protein and the presence of antioxidative chemical constituents. In conclusion, this study highlights the efficacy of both liquid-liquid extraction and macroporous resin purification techniques in the enrichment of bioactive compounds from natural food resources. The comprehensive analysis of chemical constituents and antioxidant effects of different polar fractions from Dendrobium fimbriatum Hook contributes to the understanding of its potential application in functional foods and nutraceuticals.