Anti-inflammatory, anti-colitis, and antioxidant effects of columbianadin against DSS-induced ulcerative colitis in rats via alteration of HO-1/Nrf2 and TLR4-NF-κB signaling pathway

BACKGROUND

Ulcerative colitis (UC) is a significant inflammatory bowel disease (IBD) that typically arises from chronic inflammation of the intestinal tract. Report suggest that anti-inflammatory drug plays a crucial role in the protection of UC. The recent study demonstrated that columbianadin has a protective effect against UC induced by dextran sulfate sodium (DSS) in rats through the modulation of HO-1/Nrf2 and TLR4-NF-κB signaling pathways.

MATERIAL AND METHODS

In this study, Swiss Wistar rats were utilized, and UC was induced using 2% DSS. The treatment regimen included oral administration of columbianadin (5, 10 and 15 mg/kg) and sulfasalazine to the rats. The body weight, spleen index, disease activity index (DAI), colon length, food and water intake were estimated. Moreover, antioxidant, cytokines, inflammatory and apoptosis parameters were determined. mRNA expression levels were also quantitatively analyzed.

RESULTS

Columbianadin treatment significantly (P < 0.001) boosted the body weight and suppressed the DAI. Columbianadin significantly (P < 0.001) enhanced the colon length and repressed the spleen index along with enhanced food and water intake. Columbianadin significantly (P < 0.001) suppressed the level of lactate dehydrogenase (LDH), myeloperoxidase (MPO) and altered the level of oxidative stress parameters such as catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), glutathione peroxidase (GPx), malonaldehyde (MDA), nitric oxide (NO), SA; cytokines level such as interleukin (IL)-1, 1β, 6, 10, 17, 18, TNF-α; inflammatory parameters viz., cyclooxygenase-2 (COX-2), prostaglandin (PGE2), inducible nitric oxide synthetase (iNOS), nuclear factor kappa B (NF-κB), transforming growth factor (TGF-β); apoptosis parameters include Bax, Bcl-2, Bcl-2/Bax ratio, caspase-1 and A-caspase-3 activity, respectively. Columbianadin significantly altered the mRNA expression of IFN-γ, IL-6, IL-1β, IL-8, TNF-α, NF-κB, TLR4, Bcl-2, caspase-9, Bax, p38, ASC, MCP-1, ZO-1, and Ocln. While this study focused on COX-2 modulation as a marker of inflammatory response, no direct measurements or inferences were made regarding leukotriene activity, which involves a separate lipoxygenase pathway.

CONCLUSION

Columbianadin exhibited the protective effect against DSS-induced UC via alteration of HO-1/Nrf2 and TLR4-NF-κB signaling pathway.

Therapeutic Efficacy and Underlying Mechanisms of a Mannoglucan from Hirsutella sinensis Mycelium on Dextran Sulfate Sodium-Induced Inflammatory Bowel Disease in Mice: Modulation of the Intestinal Barrier, Oxidative Stress and Gut Microbiota

Hirsutella sinensis (H. sinensis), a non-sexual form of the valuable Chinese medicinal herb, demonstrates various biological activities, such as immune modulation and antioxidative capabilities. Nonetheless, the effects of bioactive polysaccharides derived from H. sinensis on colitis have yet to be investigated. In our prior research, we extracted a mannoglucan (HSWP-1d) from H. sinensis and found that it attenuates TGF-β1-induced epithelial-mesenchymal transition. The present study investigated the protective effects of HSWP-1d against colitis induced by dextran sulfate sodium (DSS) in mice. The results demonstrate that HSWP-1d effectively ameliorates symptoms of colitis and preserves the intestinal barrier's stability by enhancing the expression of tight junction proteins. The administration of HSWP-1d results in a reduction in oxidative stress through the augmentation of antioxidative enzyme activities, concomitant with the suppression of oxidative product generation. Simultaneously, HSWP-1d reduced the levels of pro-inflammatory cytokines while elevating the levels of anti-inflammatory cytokines, effectively mitigating the inflammatory response. Furthermore, HSWP-1d influences and alters short-chain-fatty-acid (SCFA) levels, thereby enhancing the intestinal microenvironment. In conclusion, HSWP-1d contributes to intestinal well-being and holds potential as both a therapeutic choice and a supplier of essential nutrients for the amelioration of colitis.

Grifola frondosa polysaccharide's therapeutic potential in oxazolone-induced ulcerative colitis

Grifola frondosa polysaccharide (GFP) is a consumable fungus recognized for its potential health advantages. The present study aimed to investigate the development and potential etiologies of ulcerative colitis (UC) utilizing oxazolone (OXZ) as an inducer in mice, along with assessing the therapeutic effects of GFP at varying doses in UC mice, with sulfasalazine (SASP) serving as the positive control. The obtained results indicated that OXZ intervention in mice induced numerous physical manifestations of UC, including increased disease activity index (DAI), decreased goblet cell division, enhanced fibrosis, reduced expression of Claudin1 and Zona encludens protein1 (ZO-1), decreased proliferative activity of colonic mucosal epithelial cells, disturbed oxidation balance, and alterations in intestinal flora. Nonetheless, GFP intervention significantly ameliorated or even resolved these abnormal indicators to a considerable extent. Consequently, this study suggests that GFP might serve as a prebiotic to regulate intestinal flora, mitigate enterotoxin production, restore oxidative balance, thereby reducing the generation of inflammatory mediators, restoring the intestinal barrier, and ultimately improving OXZ-induced UC in mice. GFP demonstrates promising potential as a candidate drug for colitis treatment and as a dietary supplement for alleviating intestinal inflammatory issues.

The Potential Role of Plant Polysaccharides in Treatment of Ulcerative Colitis

Ulcerative colitis (UC) results in inflammation and ulceration of the colon and the rectum's inner lining. The application of herbal therapy in UC is increasing worldwide. As natural macromolecular compounds, polysaccharides have a significant role in the treatment of UC due to advantages of better biodegradation, good biocompatibility, immunomodulatory activity, and low reactogenicity. Therefore, polysaccharide drug formulation is becoming a potential candidate for UC treatment. In this review, we summarize the etiology and pathogenesis of UC and the therapeutic effects of polysaccharides on UC, such as regulating the expression of cytokines and tight junction proteins and modulating the balance of immune cells and intestinal microbiota. Polysaccharides can also serve as drug delivery carriers to enhance drug targeting and reduce side effects. This review provides a theoretical basis for applying natural plant polysaccharides in the prevention and treatment of UC.

Establishment and Evaluation of a Mouse Model of Experimental Ulcerative Colitis Induced by the Gavage Administration of Dextran Sulfate Sodium

Given the critical role of dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mouse models in the appraisal of associated therapeutic drugs, the optimization of the administration method and dosages is of paramount importance. Therefore, UC was induced in mice through the gavage administration of a DSS solution instead of free drinking water. The effects of varying daily dosages (2, 4, 6, and 8 g/kg) and frequencies (once or twice) of administration on the body weight and survival rate of the model mice were evaluated. Concurrently, the inflammatory indicators and tissue sections of the model mice were thoroughly evaluated. The results revealed that when the daily dosage reached 8 g/kg, the dosage exhibited a high level of toxicity, resulting in a high mortality rate among the mice. The DSS administration of 6 g/kg*2 not only elicited conspicuous symptoms, significant weight loss, substantial shortening of the colon, and significant changes in various inflammatory indicators, such as myeloperoxidase (MPO), nitric oxide (NO), reactive oxygen species (ROS), and glutathione (GSH), but it also maintained a high survival rate in the UC mice. The findings from this experiment lay a solid experimental foundation for future research on drugs intended for the treatment of UC.

Aloe vera-An Extensive Review Focused on Recent Studies

Since ancient times, Aloe vera L. (AV) has attracted scientific interest because of its multiple cosmetic and medicinal properties, attributable to compounds present in leaves and other parts of the plant. The collected literature data show that AV and its products have a beneficial influence on human health, both by topical and oral use, as juice or an extract. Several scientific studies demonstrated the numerous biological activities of AV, including, for instance, antiviral, antimicrobial, antitumor, and antifungal. Moreover, its important antidepressant activity in relation to several diseases, including skin disorders (psoriasis, acne, and so on) and prediabetes, is a growing field of research. This comprehensive review intends to present the most significant and recent studies regarding the plethora of AV's biological activities and an in-depth analysis exploring the component/s responsible for them. Moreover, its morphology and chemical composition are described, along with some studies regarding the single components of AV available in commerce. Finally, valorization studies and a discussion about the metabolism and toxicological aspects of this "Wonder Plant" are reported.

An Isofibrous Diet with Fiber Konjac Glucomannan Ameliorates Salmonella typhimurium-Induced Colonic Injury by Regulating TLR2-NF-κB Signaling and Intestinal Microbiota in Mice

This study aimed to investigate the hypothesis that dietary konjac glucomannan (KGM) could alleviate Salmonella typhimurium-induced colitis by modulating intestinal microbiota. Mice were fed an isocaloric and isofibrous diet supplemented with either 7% KGM or cellulose and were treated with 5 × 108 CFU of S. typhimurium. The results showed that KGM had an average molecular weight of 936 kDa and predominantly consisted of mannose and glucose at a molar ratio of 1:1.22. In vivo studies demonstrated that dietary KGM effectively mitigated colonic lesions, oxidative stress, disruption of tight junction protein 2 and occludin, and the inflammatory response induced by S. typhimurium. Moreover, KGM administration alleviated the dramatic upregulation of toll-like receptor 2 (TLR2) and phosphonuclear factor κB (NF-κB) protein abundance, induced by Salmonella treatment. Notably, dietary KGM restored the reduced Muribaculaceae and Lactobacillus abundance and increased the abundance of Blautia and Salmonella in S. typhimurium-infected mice. Spearman correlation analysis revealed that the gut microbiota improved by KGM contribute to inhibit inflammation and oxidative stress. These results demonstrated the protective effects of dietary KGM against colitis by modulating the gut microbiota and the TLR2-NF-κB signaling pathway in response to Salmonella infection.

Regulation of glycose and lipid metabolism and application based on the colloidal nutrition science properties of konjac glucomannan: A comprehensive review

The physicochemical properties of dietary fiber in the gastrointestinal tract, such as hydration properties, adsorption properties, rheological properties, have an important influence on the physiological process of host digestion and absorption, leading to the differences in satiety and glucose and lipid metabolisms. Based on the diversified physicochemical properties of konjac glucomannan (KGM), it is meaningful to review the relationship of structural characteristics, physicochemical properties and glycose and lipid metabolism. Firstly, this paper bypassed the category of intestinal microbes, and explained the potential of dietary fiber in regulating glucose and lipid metabolism during nutrient digestion and absorption from the perspective of colloidal nutrition. Secondly, the modification methods of KGM to regulate its physicochemical properties were discussed and the relationship between KGM's molecular structure types and glycose and lipid metabolism were summarized. Finally, based on the characteristics of KGM, the application of KGM in the main material and ingredients of fat reduction food was reviewed. We hope this work could provide theoretical basis for the study of dietary fiber colloid nutrition science.

Ameliorative effect of bound polyphenols in mung bean coat dietary fiber on DSS-induced ulcerative colitis in mice: the intestinal barrier and intestinal flora

The consumption of dietary fiber is beneficial for gut health, but the role of bound polyphenols in dietary fiber has lacked systematic study. The aim of this study is to evaluate the ameliorative effect of mung bean coat dietary fiber (MDF) on DSS-induced ulcerative colitis in mice in the presence and absence of bound polyphenols. Compared to polyphenol-removed MDF (PR-MDF), MDF and formulated-MDF (F-MDF,backfilling polyphenols by the amount of extracted from MDF into PR-MDF) alleviated symptoms such as weight loss and colonic injury in mice with colitis, effectively reduced excessive inflammatory responses, and the bound polyphenols restored the integrity of the intestinal barrier by promoting the expression of tight junction proteins. Additionally, bound polyphenols restored the expression of autophagy-related proteins (mTOR, beclin-1, Atg5 and Atg7) and inhibited the excessive expression of apoptotic-related proteins (Bax, caspase-9, and caspase-3). Furthermore, bound polyphenols could ameliorate the dysregulation of the intestinal microbiota by increasing the abundance of beneficial bacteria and inhibiting the abundance of harmful bacteria. Thus, it can be concluded that the presence of bound polyphenols in MDF plays a key role in the alleviation of DSS-induced ulcerative colitis.

Critical review on the research of chemical structure, bioactivities, and mechanism of actions of Dendrobium officinale polysaccharide

Dendrobium officinale (Tie-Pi-Shi-Hu) is a precious traditional Chinese medicine (TCM). The principal active components are polysaccharides (DOP), which have a high potency in therapeutic applications. However, limitations in structure analysis and underlying mechanism investigation impede its further research. This review systemically and critically summarises current understanding in both areas, and points out the influence of starch impurities and the role of gut microbiota in DOP research. As challenges faced in studying natural polysaccharide investigations are common, this review contributes to a broader understanding of polysaccharides beyond DOP.

Dendrobium officinale regulate lipid metabolism in diabetic mouse liver via PPAR-RXR signaling pathway: Evidence from an integrated multi-omics analysis

Dendrobium officinale (DEN) is recognized as a kind of functional food that can effectively ameliorate endocrine and metabolic disruptions. This study delved into the pharmacological mechanism of DEN on hepatic lipotoxicity associated with Type II diabetes mellitus (T2DM). In vivo study experiments on db/db mice indicated that DEN treatment notably enhanced liver function, decreased blood lipid levels, and improved insulin sensitivity. Non-targeted metabolomics analysis revealed that DEN significantly ameliorated metabolism pathways, including lipoic acid, linoleic acid, bile secretion, and the alanine/aspartate/glutamate metabolism, as well as taurine and hypotaurine metabolism. Transcriptomics analysis demonstrated DEN treatment could modulate the expression of genes such as Cpt1b, Scd1, G6pc2, Fos, Adrb2, Atp2a1, Ppp1r1b, and Cyp7a1. Furthermore, Proteomics analysis indicated that the beneficial effect of DEN on lipid metabolism was linked to pathways like AMPK and PPAR signaling. The integrative analysis of multi-omics revealed that the PPAR-RXR signaling was critical to the therapeutic effect of DEN on T2DM-induced fatty liver. Additionally, in vitro study on AML-12 cells confirmed that DEN counteract PA-induced lipid accumulation by activating the PPAR-RXR pathway. Overall, these findings suggested that DEN exhibited the potential to mitigate T2DM-induced hepatic lipo-toxicity and manage lipid imbalances in T2DM.

Caragana sinica (Buc'hoz) Rehd. (jin ji er) polysaccharide regulates the immune function and intestinal microbiota of cyclophosphamide (CTX) induced immunosuppressed mice

ETHNOPHARMACOLOGICAL RELEVANCE

Caragana sinica (Buc'hoz) Rehd. is a plant widely grown in Yunnan, China, for both medicinal and edible purposes. The "National Compilation of Chinese Herbal Medicine" describes its nature as "slightly temperate and sweet". Caragana sinica is usually medicated with whole herbs, the main function is to replenish the kidneys and stop bleeding. Caragana sinica was used in folk medicine in Chuxiong, Yunnan, to treat deficiency colds, fatigue, fever, cough, hypertension, and other diseases.

AIM OF THE STUDY

This article investigates the structural characteristics of Caragana sinica polysaccharide (CSP) and explores its immune-regulatory activity and molecular biological mechanisms in cyclophosphamide-induced immunosuppressed mice, as well as its effects on intestinal bacteria.

METHODS

With the water-extraction and alcohol-precipitation method, Caragana sinica polysaccharide were extracted, obtaining CSP by purification. A variety of methods and techniques have been used to analyze the chemical properties and structural characteristics of CSP. Immunosuppressive mice model was established through intraperitoneal injection of cyclophosphamide (CTX) to study the immune-regulatory effects and mechanisms of CSP.

RESULTS

The data indicated that CSP is a neutral heteropolysaccharide mainly composed of arabinose and galactose. This article uses immunosuppressive mice induced by cyclophosphamide (CTX) as the model. The results showed that CSP can promote the immune function of CTX treated immunosuppressed mice and regulate the diversity and composition of intestinal microbiota. CSP can increase macrophage phagocytosis, NK cell killing activity, and lymphocyte proliferation activity. It can also repair the index and morphological damage of the thymus and spleen. And by binding to the TLR4 receptor, MyD88 was activated and interacted with TRAF6 to promote the transfer of NF-κB into the nucleus. Thereby promoting cytokine release and increasing the production of IL-1β, IL-6, IL-10, TNF-α, IgA, and IgG in the serum. CSP also effectively alleviated the liver damage caused by CTX through antioxidant activity. Furthermore, CSP can dramatically affect the intestinal microbiota and the body's immunity by boosting the relative presence of Bacteroides and Verrucamicrobiota.

CONCLUSIONS

Research results indicated that CSP can regulate the immune function of mice, providing a basis for developing CSP as a potential immune modulator and functional food.

Agaricus bisporus polysaccharides ameliorate ulcerative colitis in mice by modulating gut microbiota and its metabolism

The gut microbiota plays a central role in maintaining human health and has been linked to many gastrointestinal diseases such as ulcerative colitis (UC). Agaricus bisporus is a famous edible mushroom, and Agaricus bisporus polysaccharides (ABPs) and the two purified fractions (ABP-1 and ABP-2) were demonstrated to exhibit immunomodulatory activity in our previous study. Herein, we further found that ABPs, ABP-1, and ABP-2 possessed therapeutic effects against dextran sodium sulfate (DSS)-induced colitis in mice. ABPs, ABP-1, and ABP-2 could relieve body weight loss, colon atrophy, and histological injury, increase tight junction proteins, restore gut-barrier function, and inhibit inflammation. ABP-2 with a lower molecular weight (1.76 × 104 Da) showed a superior therapeutic effect than ABP-1 with a higher molecular weight (8.86 × 106 Da). Furthermore, the effects of ABP-1 and ABP-2 were microbiota-dependent, which worked by inducing Norank_f__Muribaculaceae and Akkermansia and inhibiting Escherichia-Shigella and Proteus. In addition, untargeted fecal metabolomic analysis revealed distinct modulation patterns of ABP-1 and ABP-2. ABP-1 mainly enriched steroid hormone biosynthesis, while ABP-2 significantly enriched bile secretion and tryptophan metabolism. In summary, ABPs, especially low-molecular-weight fraction, represent novel prebiotics for treatment of inflammatory gastrointestinal diseases.

Toll-like receptors in inflammatory bowel disease: A review of the role of phytochemicals

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic inflammation within the gastrointestinal tract with a remarkable impact on patients' quality of life. Toll-like receptors (TLR), as a key contributor of immune system in inflammation, has a critical role in the pathogenesis of IBD and thus, can be a suitable target of therapeutic agents. Medicinal plants have long been considered as a source of bioactive agents for different diseases, including IBD.

PURPOSE

This review discusses current state of the art on the role of plant-derived compounds for the management of IBD with a focus on TLRs.

METHODS

Electronic database including PubMed, Web of Science, and Scopus were searched up to January 2023 and all studies in which anticolitis effects of a phytochemical was assessed via modulation of TLRs were considered.

RESULTS

Different categories of phytochemicals, including flavonoids, lignans, alkaloids, terpenes, saccharides, and saponins have demonstrated modulatory effects on TLR in different animal and cell models of bowel inflammation. Flavonoids were the most studied phytochemicals amongst others. Also, TLR4 was the most important type of TLRs which were modulated by phytochemicals. Other mechanisms such as inhibition of pro-inflammatory cytokines, nuclear factor-κB pathway, nitric oxide synthesis pathway, cyclooxygenase-2, lipid peroxidation, as well as induction of endogenous antioxidant defense mechanisms were also reported for phytochemicals in various IBD models.

CONCLUSION

Taken together, a growing body of pre-clinical evidence support the efficacy of herbal compounds for the treatment of IBD via modulation of TLRs. Future clinical studies are recommended to assess the safety and efficacy of these compounds in human.

Antinociceptive Effect of Dendrobii caulis in Paclitaxel-Induced Neuropathic Pain in Mice

Paclitaxel-induced neuropathic pain (PINP) is a serious adverse effect of chemotherapy. Dendrobii caulis (D. caulis) is a new food source used as herbal medicine in east Asia. We examined the antinociceptive effects of D. caulis extract on PINP and clarified the mechanism of action of transient receptor potential vanilloid 1 receptor (TRPV1) in the spinal cord. PINP was induced in male mice using multiple intraperitoneal injections of paclitaxel (total dose, 8 mg/kg). PINP was maintained from D10 to D21 when assessed for cold and mechanical allodynia. Oral administration of 300 and 500 mg/kg D. caulis relieved cold and mechanical allodynia. In addition, TRPV1 in the paclitaxel group showed increased gene and protein expression, whereas the D. caulis 300 and 500 mg/kg groups showed a significant decrease. Among various substances in D. caulis, vicenin-2 was quantified by high-performance liquid chromatography, and its administration (10 mg/kg, i.p.) showed antinociceptive effects similar to those of D. caulis 500 mg/kg. Administration of the TRPV1 antagonist capsazepine also showed antinociceptive effects similar to those of D. caulis, and D. caulis is thought to exhibit antinociceptive effects on PINP by modulating the spinal TRPV1.

The maca protein ameliorates DSS-induced colitis in mice by modulating the gut microbiota and production of SCFAs

Maca is a functional food with anti-inflammatory activity, and it is rich in protein. Currently, inflammatory bowel disease (IBD) is a common gastrointestinal disease. However, there is little research focusing on the effect of maca protein (MCP) on IBD. In this study, we extracted MCP from maca root and explored its effect and mechanism on improving dextran sodium sulfate (DSS)-induced IBD in mice. The results indicated that MCP intervention alleviated the clinical symptoms and colon tissue damage of mice with DSS-induced colitis and inhibited the expression of inflammatory factors. Moreover, it can modulate the gut microbiota composition in mice with DSS-induced colitis. The regulation is achieved by reducing the relative abundance of the IBD-exacerbating key bacterial genera: Lachnospiraceae_NK4A136_group, Bacteroides, Desulfovibrio, Prevotella, Helicobacter and Sutterella, while increasing the relative abundance of the IBD-alleviating key bacterial genera: norank_f_Muribaculaceae, Lactobacillus, Oscillospira, Akkermansia and Bifidobacterium. MCP can also promote the production of short-chain fatty acids (SCFAs). The further western blotting results indicated that MCP can regulate the Treg/Th17 immune balance in mice with colitis via the SCFAs-GPR41/43/HDAC1 signaling pathway. Overall, MCP can alleviate colitis by comprehensively regulating the gut microbiota and inflammatory response. It may be a promising functional component that reduces the risk of colitis by maintaining intestinal health.

Structure, Health Benefits, Mechanisms, and Gut Microbiota of Dendrobium officinale Polysaccharides: A Review

Dendrobium officinale polysaccharides (DOPs) are important active polysaccharides found in Dendrobium officinale, which is commonly used as a conventional food or herbal medicine and is well known in China. DOPs can influence the composition of the gut microbiota and the degradation capacity of these symbiotic bacteria, which in turn may determine the efficacy of dietary interventions. However, the necessary analysis of the relationship between DOPs and the gut microbiota is lacking. In this review, we summarize the extraction, structure, health benefits, and related mechanisms of DOPs, construct the DOPs-host axis, and propose that DOPs are potential prebiotics, mainly composed of 1,4-β-D-mannose, 1,4-β-D-glucose, and O-acetate groups, which induce an increase in the abundance of gut microbiota such as Lactobacillus, Bifidobacterium, Akkermansia, Bacteroides, and Prevotella. In addition, we found that when exposed to DOPs with different structural properties, the gut microbiota may exhibit different diversity and composition and provide health benefits, such as metabolism regulations, inflammation modulation, immunity moderation, and cancer intervention. This may contribute to facilitating the development of functional foods and health products to improve human health.

Polysaccharide from Smilax glabra Roxb Mitigates Intestinal Mucosal Damage by Therapeutically Restoring the Interactions between Gut Microbiota and Innate Immune Functions

Smilax glabra Roxb (S. glabra) is a conventional Chinese medicine that is mainly used for the reliability of inflammation. However, bioactive polysaccharides from S. glabra (SGPs) have not been thoroughly investigated. Here, we demonstrate for the first time that SGPs preserve the integrity of the gut epithelial layer and protect against intestinal mucosal injury induced by dextran sulfate sodium. Mechanistically, SGPs mitigated colonic mucosal injury by restoring the association between the gut flora and innate immune functions. In particular, SGPs increased the number of goblet cells, reduced the proportion of apoptotic cells, improved the differentiation of gut tight junction proteins, and enhanced mucin production in the gut epithelial layer. Moreover, SGPs endorsed the propagation of probiotic bacteria, including Lachnospiraceae bacterium, which strongly correlated with decreased pro-inflammatory cytokines via the blocking of the TLR-4 NF-κB and MyD88 pathways. Overall, our study establishes a novel use of SGPs for the treatment of inflammatory bowel disease (IBD)-associated mucosal injury and provides a basis for understanding the therapeutic effects of natural polysaccharides from the perspective of symbiotic associations between host innate immune mechanisms and the gut microbiome.

Recent progress in plant-derived polysaccharides with prebiotic potential for intestinal health by targeting gut microbiota: a review

Natural products of plant origin are of high interest and widely used, especially in the food industry, due to their low toxicity and wide range of bioactive properties. Compared to other plant components, the safety of polysaccharides has been generally recognized. As dietary fibers, plant-derived polysaccharides are mostly degraded in the intestine by polysaccharide-degrading enzymes secreted by gut microbiota, and have potential prebiotic activity in both non-disease and disease states, which should not be overlooked, especially in terms of their involvement in the treatment of intestinal diseases and the promotion of intestinal health. This review elucidates the regulatory effects of plant-derived polysaccharides on gut microbiota and summarizes the mechanisms involved in targeting gut microbiota for the treatment of intestinal diseases. Further, the structure-activity relationships between different structural types of plant-derived polysaccharides and the occurrence of their prebiotic activity are further explored. Finally, the practical applications of plant-derived polysaccharides in food production and food packaging are summarized and discussed, providing important references for expanding the application of plant-derived polysaccharides in the food industry or developing functional dietary supplements.

A Poly-D-Mannose Synthesized by a One-Pot Method Exhibits Anti-Biofilm, Antioxidant, and Anti-Inflammatory Properties In Vitro

In this study, D-mannose was used to synthesize poly-D-mannose using a one-pot method. The molecular weight, degree of branching, monosaccharide composition, total sugar content, and infrared spectrum were determined. In addition, we evaluated the safety and bioactivity of poly-D-mannose including anti-pathogen biofilm, antioxidant, and anti-inflammatory activity. The results showed that poly-D-mannose was a mixture of four components with different molecular weights. The molecular weight of the first three components was larger than 410,000 Da, and that of the fourth was 3884 Da. The branching degree of poly-D-mannose was 0.53. The total sugar content was 97.70%, and the monosaccharide was composed only of mannose. The infrared spectra showed that poly-D-mannose possessed characteristic groups of polysaccharides. Poly-D-mannose showed no cytotoxicity or hemolytic activity at the concentration range from 0.125 mg/mL to 8 mg/mL. In addition, poly-D-mannose had the best inhibition effect on Salmonella typhimurium at the concentration of 2 mg/mL (68.0% ± 3.9%). The inhibition effect on Escherichia coli O157:H7 was not obvious, and the biofilm was reduced by 37.6% ± 2.9% at 2 mg/mL. For Staphylococcus aureus and Bacillus cereus, poly-D-mannose had no effect on biofilms at low concentration; however, 2 mg/mL of poly-D-mannose showed inhibition rates of 33.7% ± 6.4% and 47.5% ± 4%, respectively. Poly-D-mannose showed different scavenging ability on free radicals. It showed the best scavenging effect on DPPH, with the highest scavenging rate of 74.0% ± 2.8%, followed by hydroxyl radicals, with the scavenging rate of 36.5% ± 1.6%; the scavenging rates of superoxide anion radicals and ABTS radicals were the lowest, at only 10.1% ± 2.1% and 16.3% ± 0.9%, respectively. In lipopolysaccharide (LPS)-stimulated macrophages, poly-D-mannose decreased the secretion of nitric oxide (NO) and reactive oxygen species (ROS), and down-regulated the expression of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). Therefore, it can be concluded that poly-D-mannose prepared in this research is safe and has certain biological activity. Meanwhile, it provides a new idea for the development of novel prebiotics for food and feed industries or active ingredients used for pharmaceutical production in the future.

Effects of sheep whey protein combined with Fu brick tea polysaccharides and stachyose on immune function and intestinal metabolites of cyclophosphamide-treated mice

BACKGROUND

Sheep whey protein (SWP), Fu brick tea polysaccharides (FBTP) and stachyose (STA) have been shown to improve immunity, but little is known about the regulatory effect of SWP, FBTP, STA and their combined formula (CF) on immune function and intestinal metabolism of immunosuppressed mice induced by cyclophosphamide (CTX).

RESULTS

Administration of SWP, FBTP, STA or CF restored the levels of body weight, immune organ index, immune organ morphology, cytokines and immunoglobulins in CTX immunosuppressed mice. Interestingly, CF improved all the mentioned parameters more effective than administration of SWP, FBTP or STA alone. In addition, CF was more effective to increase the levels of intestinal immune-related gene expression than FBTP, SWP or STA alone in immunosuppressed mice, suggesting that CF exhibited excellent intestinal immune regulation function. CF also significantly improved cecal concentrations of short-chain fatty acids of CTX-treated mice. Furthermore, metabolomics analysis demonstrated that CF recovered the levels of 28 metabolites associated with the CTX treatment to the levels of normal mice.

CONCLUSION

Conclusively, these findings suggested that CF as a functional food combination of SWP, FBTP and STA could promote the immune function against human diseases, which providing theoretical support for the co-ingestion of SWP and functional sugars as a feasible strategy for improving the body immunity in the future. © 2023 Society of Chemical Industry.

Alleviative effects of natural plant polysaccharides against DSS-induced ulcerative colitis via inhibiting inflammation and modulating gut microbiota

Ulcerative colitis (UC) treatment usually involves either drug therapy or surgery. Natural food polysaccharides have showed great potential for preventing UC. In this study, the therapeutic effects of Cyclocarya paliurus (Batal.) Iljinskaja polysaccharide (CP) and Chinese yam polysaccharide (CYP) on dextran sodium sulfate (DSS)-induced mice UC model and their underlying mechanisms were explored. The results suggested that CP and CYP could improve colitis symptoms in DSS-induced mice, enhance the production of IL-10, inhibit cytokines (IL-1β, TNF-α) and reduce MPO activity. Furthermore, they maintained the integrity of intestine by improving the expression of mucin MUC-2, ZO-1 and occludin, which in turn reduced the contents of lipopolysaccharide binding protein (LBP) and endotoxin (ET) in serum and oxidative stress in liver. Finally, they modulated the composition and metabolism of gut microbiota. Notably, Alistipes and Bacteroides were the specific genera in CP and CYP groups, respectively. These findings indicated that polysaccharides might alleviate the development of colitis and inform other relevant studies.

A critical review on inflammatory bowel diseases risk factors, dietary nutrients regulation and protective pathways based on gut microbiota during recent 5 years

The treatment of inflammatory bowel diseases (IBDs) has become a worldwide problem. Intestinal flora plays an important role in the development and progression of IBDs. Various risk factors (psychology, living habits, dietary patterns, environment) influence the structure and composition of the gut microbiota and contribute to the susceptibility to IBDs. This review aims to provide a comprehensive overview on risk factors regulating intestinal microenvironment which was contributed to IBDs. Five protective pathways related to intestinal flora were also discussed. We hope to provide systemic and comprehensive insights of IBDs treatment and to offer theoretical guidance for personalized patients with precision nutrition.

Dendrobium officinale alleviates high-fat diet-induced nonalcoholic steatohepatitis by modulating gut microbiota

Introduction

The gut microbiota plays an important role in the development of nonalcoholic steatohepatitis (NASH). This study investigated the preventive effect of Dendrobium officinale (DO), including whether its effect was related to the gut microbiota, intestinal permeability and liver inflammation.

Methods

A NASH model was established in rats using a high-fat diet (HFD) and gavage with different doses of DO or Atorvastatin Calcium (AT) for 10 weeks. Body weight and body mass index along with liver appearance, weight, index, pathology, and biochemistry were measured to assess the preventive effects of DO on NASH rats. Changes in the gut microbiota were analyzed by 16S rRNA sequencing, and intestinal permeability and liver inflammation were determined to explore the mechanism by which DO treatment prevented NASH.

Results

Pathological and biochemical indexes showed that DO was able to protect rats against HFD-induced hepatic steatosis and inflammation. Results of 16S rRNA sequencing showed that Proteobacteria, Romboutsia, Turicibacter, Lachnoclostridium, Blautia, Ruminococcus_torques_group, Sutterella, Escherichia-Shigella, Prevotella, Alistipes, and Lactobacillus_acidophilus differed significantly at the phylum, genus, and species levels. DO treatment modulated the diversity, richness, and evenness of gut microbiota, downregulated the abundance of the Gram-negative bacteria Proteobacteria, Sutterella, and Escherichia-Shigella, and reduced gut-derived lipopolysaccharide (LPS) levels. DO also restored expression of the tight junction proteins, zona occludens-1 (ZO-1), claudin-1, and occludin in the intestine and ameliorated the increased intestinal permeability caused by HFD, gut microbiota such as Turicibacter, Ruminococcus, Escherichia-Shigella, and Sutterella, and LPS. Lower intestinal permeability reduced LPS delivery to the liver, thus inhibiting TLR4 expression and nuclear factor-kappaB (NF-κB) nuclear translocation, improving liver inflammation.

Discussion

These results suggest that DO may alleviate NASH by regulating the gut microbiota, intestinal permeability, and liver inflammation.

Polysaccharides from natural Cordyceps sinensis attenuated dextran sodium sulfate-induced colitis in C57BL/6J mice

As potential candidates for treating ulcerative colitis (UC), polysaccharides have been attracting extensive interest in recent years. Cordyceps sinensis (C. sinensis) is a kind of traditional Chinese edible food, and its polysaccharide fractions have been found to be effective in regulating immunity and protecting the kidneys. To determine the potential function of polysaccharides from natural C. sinensis on UC, their effects in terms of histological, serological, biochemical, and immunological aspects on dextran sulphate sodium (DSS)-induced colitis mice model were investigated. Results showed that the polysaccharides significantly alleviated colitis by increasing the colon length, alleviating colon tissue damage, and inhibiting the activation of the NF-κB pathway. In addition, polysaccharides reduced the contents of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the serum, increased the number of goblet cells, and improved the expression of intestinal tight junction proteins (Occludin and Claudin-1). They also evidently enhanced the formation of IgA-secretory cells and sIgA contents. Furthermore, the polysaccharides modulated the gut microbiota by decreasing the relative abundance of Bilophila and increasing the relative abundance of Dehalobacterium, Coprococcus, Oscillospira, and Desulfovibrio, which is accompanied by an increase in the short chain fatty acids' (SCFAs) concentrations in cecal contents. These results suggested that C. sinensis polysaccharides possessed promising intervening effects on experimental acute UC in mice.

Green tea EGCG effectively alleviates experimental colitis in middle-aged male mice by attenuating multiple aspects of oxi-inflammatory stress and cell cycle deregulation

Age-dependent increased risk of inflammatory bowel diseases such as ulcerative colitis is being increasingly realized, and yet therapies targeting this disorder within the purview of aging are limited. The present study attempted to assess the efficacy of green tea epigallocatechin gallate (EGCG) consumption in preventing the severity and progression of dextran sulphate sodium (DSS)-induced ulcerative colitis in 18 months old middle-aged male mice. Acute colitis was induced in animals using DSS and protective effects of EGCG consumption were examined. Different parameters related to disease progression and molecular markers related to oxi-inflammatory stress, localized and systemic cytokine response, epithelial barrier integrity, and cell cycle progression profile were evaluated. DSS treatment induced rapid and severe symptoms of colitis such as consistently increased DAI score, shortened and inflamed colon accompanied by increased levels of inflammatory proteins (TNFα/IL-6/IL-1β) in both the colon tissue and cultured splenocytes indicating exaggerated Th1 immune response. Markers of oxidative stress increased while antioxidant defences and the expression of tight junction genes in the colonic cells were attenuated. Dysregulation in the expression of cell cycle inhibitory genes (p53/p21^WAF1/p16^Ink4a) indicated possible induction of colitis-induced dysplasia. On the other hand, EGCG consumption strongly attenuated all the measured ostensible as well as molecular markers of the disease progression as evidenced by improved DAI score, cellular antioxidant capacity, attenuated Th1 cytokine response both in the colon and cultured splenocytes, enhanced expression of tight junction genes, and cell cycle inhibitors thereby suggesting systemic effects of EGCG. Together, these observations suggest that drinking EGCG-rich green tea can be a significant way of managing the severity of colitis during aging.

Exopolysaccharide from Lactobacillus rhamnosus ZFM231 alleviates DSS-induced colitis in mice by regulating gut microbiota

BACKGROUND

The exopolysaccharides (EPS) produced by Lactobacillus and other probiotics are associated with many benefits, such as immune regulation, antioxidant properties, antitumor effect, and regulation of intestinal microbe homeostasis. In the present study, the modulatory effect of EPS produced by Lactobacillus rhamnosus ZFM231 on the intestinal flora of mice with inflammatory bowel disease induced by dextran sulfate solution was investigated.

RESULTS

Results indicated that weight loss, colonic length, the disease activity index score and colonic tissue damage in mice were significantly improved by EPS treatment. Compared with the model group, in the EPS-treated group, the diversity of and the composition of gut microbiota at both phylum and genus levels were found to recover to the levels of normal group, indicating the effective modulation on gut microbiota by EPS; short-chain fatty acids, including acetic acid, propionic acid and butyric acid produced by intestinal microbial metabolism, increased significantly; the level of anti-inflammatory factor transforning growth factor-β significantly increased and the level of pro-inflammatory factor tumor necrosis factor-α significantly decreased in the colonic cells of EPS-treated mice.

CONCLUSION

It is clear that EPS produced by L. rhamnosus ZFM231 could find application in functional foods with the property of anti-ulcerative colitis. The experimental results provide new insights into the probiotic effect of EPS. © 2022 Society of Chemical Industry.

Effect of Lactobacillus with Feruloyl Esterase-Producing Ability on Dextran Sodium Sulfate-Induced Ulcerative Colitis in Mice

Ulcerative colitis (UC) is becoming an increasingly serious health problem. This study aimed to investigate the effect of a newly isolated Lactobacillus species that produces feruloyl esterase (FAEb) on dextran sodium sulfate (DSS)-induced UC in mice. In this study, FAEb supplementation slowed body weight loss and mitigated colon length shortening, the severity of fecal occult blood, and increases in the disease activity index (DAI) in UC model mice. FAEb supplementation was also shown to reduce the expression of proinflammatory factors, increase the antioxidant capacity, improve the production of beneficial short-chain fatty acids (SCFAs), upregulate the expression of tight junction proteins, reduce the histopathological scores, and reduce mucous barrier damage in the gut. Furthermore, FAEb supplementation was shown to inhibit inflammatory NF-κB signaling pathway activity, increase the abundance of beneficial bacteria, and regulate the balance of microbiota in the gut. These results suggest that FAEb may serve as a potential probiotic to prevent and treat UC.

Acetylated polysaccharides: Synthesis, physicochemical properties, bioactivities, and food applications

Polysaccharides are biomacromolecular widely applied in the food industry, as gelling agents, thickeners and health supplements. As hydrophobic groups, acetyls provide amphiphilicity to polysaccharides with numerous hydroxyl groups, which greatly expand the presence of polysaccharides in organic organisms and various chemical environments. Acetylation could result in diverseness and promotion of the structure of polysaccharides, which improve the physicochemical properties and biological activities. High efficient and environmentally friendly access to acetylated derivatives of different polysaccharides is being explored. This review discusses and summarizes acetylated polysaccharides in terms of synthetic methods, physicochemical properties and biological activities and emphasizes the structure-effect relationships introduced by acetyl groups to reveal the potential mechanism of acetylated polysaccharides. Acetyls with different contents and substitution sites could change the molecular weight, monosaccharide composition and spatial architecture of polysaccharides, resulting in differences among properties such as water solubility, emulsification and crystallinity. Coupled with acetyls, polysaccharides have increased antioxidant, immunomodulatory, antitumor, and pro-prebiotic capacities. In addition, their possible applications have also been discussed in green food materials, bioactive ingredient carriers and functional food products, indicating that acetylated polysaccharides hold a clear vision in food health and industrial development.

Glucomannan in Dendrobium catenatum: Bioactivities, Biosynthesis and Perspective

Dendrobium catenatum is a classical and precious dual-use plant for both medicine and food in China. It was first recorded in Shen Nong's Herbal Classic, and has the traditional functions of nourishing yin, antipyresis, tonifying the stomach, and promoting fluid production. The stem is its medicinal part and is rich in active polysaccharide glucomannan. As an excellent dietary fiber, glucomannan has been experimentally confirmed to be involved in anti-cancer, enhancing immunity, lowering blood sugar and blood lipids, etc. Here, the status quo of the D. catenatum industry, the structure, bioactivities, biosynthesis pathway and key genes of glucomannan are systematically described to provide a crucial foundation and theoretical basis for understanding the value of D. catenatum and the potential application of glucomannan in crop biofortification.

Refined polysaccharide from Dendrobium devonianum resists H1N1 influenza viral infection in mice by activating immunity through the TLR4/MyD88/NF-κB pathway

Dendrobium polysaccharide exhibits multiple biological activities, such as immune regulation, antioxidation, and antitumor. However, its resistance to viral infection by stimulating immunity is rarely reported. In this study, we explored the effect and mechanism of DVP-1, a novel polysaccharide from Dendrobium devonianum, in the activation of immunity. After being activated by DVP-1, the ability of mice to prevent H1N1 influenza virus infection was investigated. Results of immune regulation showed that DVP-1 significantly improved the immune organ index, lymphocyte proliferation, and mRNA expression level of cytokines, such as IL-1β, IL-4, IL-6, and TNF-α in the spleen. Immunohistochemical results showed that DVP-1 obviously promoted the mucosal immunity in the jejunum tissue. In addition, the expression levels of TLR4, MyD88, and TRAF6 and the phosphorylation levels of TAK1, Erk, JNK, and NF-κB in the spleen were upregulated by DVP-1. The virus infection results showed that the weight loss of mice slowed down, the survival rate increased, the organ index of the lung reduced, and the virus content in the lung decreased after DVP-1 activated immunity. By activating immunity with DVP-1, the production of inflammatory cells and inflammatory factors in BALF, and alveolar as well as peribronchiolar inflammation could be prevented. The results manifested that DVP-1 could resist H1N1 influenza virus infection by activating immunity through the TLR4/MyD88/NF-κB pathway.

Quality Markers of Dendrobium officinale by “Oligosaccharide-Spectrum-Effect” Relationships

Dendrobium officinale Kimura et Migo has been used as a traditional Chinese medicine (TCM) and a functional food for thousands of years. Carbohydrate is one of the most important effective substances and indicative components in D. officinale. However, since the qualitative and quantitative analysis of polysaccharides in D. officinale remains a challenge and limitation, herein, an oligosaccharide-quality marker approach was newly developed for quality assessment of D. officinale by spectrum–effect relationships between high performance liquid chromatographic (HPLC) fingerprints and anti-inflammatory effects. The HPLC fingerprints of 48 batches of oligosaccharides from D. officinale (DOOS) were developed and analyzed with similarity analysis (SA) and hierarchical cluster analysis (HCA), and eight common peaks were identified. In vitro screening experiment indicated that DOOS potentially inhibited nitric oxide (NO) production and effectively reduced the release of inflammatory cytokines, such as TNF-α, IL-6, and IL-1β in RAW 264.7 cells, thereby reducing the inflammatory response of cells. Finally, the HPLC fingerprint of different batches of DOOS was combined with in vitro anti-inflammatory activity to assess the spectrum–effect relationships of DOOS by gray correlation analysis (GCA), in addition, the purified oligosaccharide components were identified and validated for NO inhibitory activity. Our results showed four DOOS (maltotetraose, maltopentaose, maltohexaose, and mannohexaose) were relevant to anti-inflammatory effects and could be as quality markers for the quality control of D. officinale. It suggests that the “oligosaccharide-spectrum-effect” relationships approach is a simple and reliable method for the quality control of herb medicines or nutritious foods.

Mesona chinensis Benth Polysaccharides Alleviate DSS-Induced Ulcerative Colitis via Inhibiting of TLR4/MAPK/NF-κB Signaling Pathways and Modulating Intestinal Microbiota

SCOPE

Ulcerative colitis (UC) is a severe disease of the intestinal tract. To investigate the role of TLR4/Mitogen-activated protein kinase (MAPK)/Nuclear factor kappa-B(NF-κB) pathways and intestinal flora in UC, and the protective mechanisms of Mesona chinensis Benth polysaccharides (MBP), potential therapeutic agents due to their diabetes-relieving, cancer-suppressing, and immunomodulatory properties.

METHODS AND RESULTS

A dextran sulfate sodium (DSS)-induced mouse colitis model is used for experiments; the histopathology, immunohistochemistry, and Western blotting's results suggest that MBP can alleviate the colitis symptoms, inhibits the overproduction of TNF-α, IL-1β, promote IL-10, reduces myeloperoxidase activity, and alleviates the inflammatory response probably by inhibiting the activation of TLR4/MAPK/NF-κB pathways. Furthermore, MBP improvs the ratio of Bcl-2/BAX, maintains the intestinal integrity by promoting the levels of zonulin occludin-1 (ZO-1), occluding and mucin mucin-2 (MUC-2), reduces the levels of endotoxin (ET), lipopolysaccharide binding protein (LBP) in serum, and oxidative stress in liver. Moreover, using 16S rRNA Gene Sequencing analysis, MBP regulates gut microbiota by decreasing the abundances of Helicobacter and Prevotella and increasing the abundances of Lactobacillus and Coprococcus, reverses microbiota dysbiosis caused by DSS.

CONCLUSION

These findings confirm the anti-inflammatory effects of MBP, restoration of the intestinal barrier and intestinal flora, and have therapeutic potential to attenuate the development of UC.

MiR155 Disrupts the Intestinal Barrier by Inducing Intestinal Inflammation and Altering the Intestinal Microecology in Severe Acute Pancreatitis

BACKGROUND

Intestinal dysfunction is a common complication of acute pancreatitis. MiR155 may be involved in the occurrence and development of intestinal dysfunction mediated by acute pancreatitis, but the specific mechanism is not clear.

AIMS

To investigate the effect of miR155 on severe acute pancreatitis (SAP)-associated intestinal dysfunction and its possible mechanism in a mice model.

METHODS

In this study, SAP mice model was induced by intraperitoneal injection of caerulein and LPS in combination. Adeno-associated virus (AAV) was given by tail vein injection before the SAP model. The pancreatic and intestinal histopathology changes were analyzed. Cecal tissue was collected for 16S rRNA Gene Sequencing. Intestinal barrier proteins ZO-1 and E-cad were measured by Immunohistochemistry Staining and Western Blot, respectively. Intestinal tissue miR155 and inflammatory factors TNF-α, IL-1β, and IL-6 were detected by Q-PCR. The expression levels of protein associated with TNF-α and TLR4/MYD88 pathway in the intestinal were detected.

RESULTS

In miR155 overexpression SAP group, the levels of tissue inflammatory factor were significantly increased, intestinal barrier proteins were significantly decreased, and the injury of intestinal was aggravated. Bacterial 16S rRNA sequencing was performed, showing miR155 promotes gut microbiota dysbiosis. The levels of TNF-α, TLR4, and MYD88 in the intestinal were detected, suggesting that miR155 may regulate gut microbiota and activate the TLR4/MYD88 pathway, thereby affecting the release of inflammatory mediators and regulating SAP-related intestinal injury. After application of miR155-sponge, imbalance of intestinal flora and destruction of intestinal barrier-related proteins have been alleviated. The release of inflammatory mediators decreased, and the histopathology injury of intestinal was improved obviously.

CONCLUSION

MiR155 may play an important role in SAP-associated intestinal dysfunction. MiR155 can significantly alter the intestinal microecology, aggravated intestinal inflammation through TLR4/MYD88 pathway, and disrupts the intestinal barrier in SAP mice.

Evaluation of the effect of prebiotic sesame candies on loperamide-induced constipation in mice

Constipation is one of the most common gastrointestinal tract symptoms. In this study, prebiotic sesame sugar (PSC) was prepared from isomalto-oligosaccharide, konjac glucomannan and sesame, and the relieving effect of PSC on constipation induced by loperamide was explored. The results showed that PSC treatment profoundly improved the defecation function and boosted intestinal motility. Moreover, PSC repaired gastrointestinal tissue injury and inflammation induced by constipation, which confirmed the effectiveness of PSC intervention in the treatment of constipation. The mechanism of PSC improving constipation might be that PSC improved the imbalance of gastrointestinal neurotransmitters and increased the content of short-chain fatty acids in feces. In conclusion, PSC dietotherapy could effectively alleviate the symptoms and lay a theoretical foundation for the development of an anti-constipation diet.

Influence of Natural Polysaccharides on Intestinal Microbiota in Inflammatory Bowel Diseases: An Overview

The incidence of inflammatory bowel disease (IBD) has increased in recent years. Considering the potential side effects of conventional drugs, safe and efficient treatment methods for IBD are required urgently. Natural polysaccharides (NPs) have attracted considerable attention as potential therapeutic agents for IBD owing to their high efficiency, low toxicity, and wide range of biological activities. Intestinal microbiota and their fermentative products, mainly short-chain fatty acids (SCFAs), are thought to mediate the effect of NPs in IBDs. This review explores the beneficial effects of NPs on IBD, with a special focus on the role of intestinal microbes. Intestinal microbiota exert alleviation effects via various mechanisms, such as increasing the intestinal immunity, anti-inflammatory activities, and intestinal barrier protection via microbiota-dependent and microbiota-independent strategies. The aim of this paper was to document evidence of NP–intestinal microbiota-associated IBD prevention, which would be helpful for guidance in the treatment and management of IBD.

Fucoidan Is Not Completely Dependent on Degradation to Fucose to Relieve Ulcerative Colitis

Recently, fucoidan has been proposed for use as a potential anti-inflammatory drug. The purpose of this study was to investigate the mechanism of fucoidan in the treatment of ulcerative colitis. We compared the anti-inflammatory effects of fucoidan and fucose induced by dextran sulfate sodium, and the effects of fucoidan and fucose on the gut microbiota of mice. Our results showed that low-dose fucoidan significantly improved weight loss, disease activity index scores, colonic shortening, colonic histopathological damage, intestinal fatty acid binding protein 2 levels, and the expression of Occludin, Claudin-4, and Claudin-1. However, both high-dose fucoidan and fucose did not perform as well as low-dose fucoidan as described above. In addition, 16S rDNA high-throughput sequencing showed that low-dose fucoidan significantly increased the abundance of Alloprevotella, and fucose significantly increased Ruminococcaceae, but neither significantly reversed the imbalance in the gut microbiota. Therefore, we inferred that the regulation of fucoidan on colitis has a unique and complex mechanism, and it is not completely dependent on degradation to fucose to relieve ulcerative colitis, nor is it achieved only by regulating the gut microbiota. The mechanism by which fucoidan treats colitis may also include reducing inflammatory cell infiltration and increasing intestinal barrier function.

A Systematic Review on Polysaccharides from Dendrobium Genus: Recent Advances in the Preparation, Structural Characterization, Bioactive Molecular Mechanisms, and Applications

Dendrobium polysaccharides (DPSs) have aroused people's increasing attention in recent years as a result of their outstanding edible and medicinal values and non-toxic property. This review systematically summarized recent progress in the different preparation techniques, structural characteristics, modification, various pharmacological activities and molecular mechanisms, structure-activity relationships, and current industrial applications in the medicinal, food, and cosmetics fields of DPSs. Additionally, some recommendations for future investigations were provided. A variety of methods were applied for the extraction and purification of DPSs. They possessed primary structures (e.g., glucomannan, rhamnogalacturonan I type pectin, heteroxylan, and galactoglucan) and conformational structures (e.g., random coil, rod, globular, and a slight triple-helical). And different molecular weights, monosaccharide compositions, linkage types, and modifications could largely affect DPSs' bioactivities (e.g., immunomodulatory, anti-diabetic, hepatoprotective, gastrointestinal protective, antitumor, anti-inflammatory, and anti-oxidant activities). It was worth mentioning that DPSs were significant pharmaceutical remedies and therapeutic supplements especially due to their strong immunity enhancement abilities. We hope that this review will lay a solid foundation for further development and applications of Dendrobium polysaccharides.

CRISPR-Cas gene editing technology and its application prospect in medicinal plants

The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas gene editing technology has opened a new era of genome interrogation and genome engineering because of its ease operation and high efficiency. An increasing number of plant species have been subjected to site-directed gene editing through this technology. However, the application of CRISPR-Cas technology to medicinal plants is still in the early stages. Here, we review the research history, structural characteristics, working mechanism and the latest derivatives of CRISPR-Cas technology, and discussed their application in medicinal plants for the first time. Furthermore, we creatively put forward the development direction of CRISPR technology applied to medicinal plant gene editing. The aim is to provide a reference for the application of this technology to genome functional studies, synthetic biology, genetic improvement, and germplasm innovation of medicinal plants. CRISPR-Cas is expected to revolutionize medicinal plant biotechnology in the near future.

Dendrobium fimbriatum Hook polysaccharide ameliorates dextran-sodium-sulfate-induced colitis in mice via improving intestinal barrier function, modulating intestinal microbiota, and reducing oxidative stress and inflammatory responses

The ameliorative effect of Dendrobium fimbriatum polysaccharide (cDFPW1) on ulcerative colitis (UC) was investigated using a dextran-sodium-sulfate-induced (DSS-induced) mouse model in the present study. The results showed that cDFPW1 effectively improved colitis in mice by ameliorating weight loss, disease activity index (DAI) and colonic pathological damage, and by protecting the intestinal barrier function integrity. Moreover, cDFPW1 modulated the composition and metabolism of intestinal microbiota through enhancing Romboutsia, Lactobacillus and Odoribacter, and reducing Parasutterella, Burkholderia-Caballeronia-Paraburkholderia and Acinetobacter in colitis mice. Notably, cDFPW1 significantly restored the homeostasis of Th17/regulatory T (Treg) cells and the expression of specific cytokines. Western blotting of colon tissues showed that cDFPW1 markedly up-regulated the expression of Nrf2 and inhibited the phosphorylation of NF-κB signaling. These results indicated that cDFPW1 possesses the potential of improving UC and its effect on palliating colitis may be connected with the regulation of Nrf2/NF-κB signaling.

Sodium butyrate alleviates intestinal injury and microbial flora disturbance induced by lipopolysaccharides in rats

Sodium butyrate alleviates LPS-induced intestinal inflammation in rats by regulating intestinal injury, inflammatory cytokine levels, and intestinal flora.

Fermented egg-milk beverage alleviates dextran sulfate sodium-induced colitis in mice through the modulation of intestinal flora and short-chain fatty acids

Fermented egg-milk beverage (FEMB) can alleviate the symptoms of intestinal diseases by regulating intestinal flora and supplying nutrition. This study investigated the protective effect of FEMB on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice. The results showed that FEMB relieved the UC mice's pathological abnormalities and colonic inflammation, and restructured the intestinal flora composition simultaneously. After FEMB treatment for 14 days, the body weight of the mice rose and the disease activity index (DAI) value decreased. Furthermore, the length and form of colons in the UC mice were notably restored. Inflammatory cells decreased or disappeared, and goblet cells and crypt were enriched and modified. 16S rRNA gene sequencing results demonstrated that FEMB treatment could increase the abundance of beneficial bacteria in the cecum content of mice, including unclassified_f_Lachnospiraceae and Lactobacillus. Moreover, probiotics that can increase the content of short-chain fatty acids (SCFAs) may contribute to inflammation alleviation. An increase in amino acids was observed in our experiment, which may benefit nutritional supplements. In conclusion, FEMB treatment can alleviate the damage of DSS-induced colitis in Balb/c mice. This study provides a theoretical basis for both the relief of inflammation and the application of FEMB.

Anti-Inflammatory, Antioxidant, and Healing-Promoting Effects of Aloe vera Extract in the Experimental Colitis in Rats

Background. Ulcerative colitis is a worldwide chronic gastrointestinal disease characterized by variable extensions of colon mucosal inflammation. The available drugs have an incomplete response with various side effects and socioeconomic impacts. Aloe barbadensis Miller (Aloe vera) is a well-known medicinal plant with diverse pharmacological and therapeutic activities. As a result, in the current study, Aloe vera was selected to evaluate its therapeutic effects on experimental colitis in rats. Methods. This study is intended to evaluate the possible beneficial effect of Aloe vera for the treatment of experimental colitis. Trinitrobenzenesulfonic acid (TNBS) was used to induce experimental colitis in 60 of 70 Wistar rats. The rats were grouped in 7 clusters including healthy control, negative, positive control (received sulfasalazine), and test groups treated with Aloe vera extracts via oral or rectal routes. Macroscopic and histologic factors as well as the biochemical parameters were evaluated on day 7. Results. In the present study, it was found that serum levels of tumor necrosis factor-α (75 vs. 44 pg./ml), interleukin-6 (41 vs. 21 pg/ml), and nitric oxide (24 vs. 6 μm/ml) in TNBS-induced untreated colitis treatment were significantly increased as compared to healthy control. Similar patterns were also observed in malondialdehyde (76.41 vs. 236.35 μg/mg) and myeloperoxidase (4.24 vs. 29.38 U/mg) in colonic tissue. Among different treatments, rectal administration of Aloe vera extract (400 mg/kg) exhibited the best result in which serum concentration of tumor necrosis factor-α (55 pg/ml), interleukin-6 (24 pg/ml), and nitric oxide (10 μm/ml) and the levels of malondialdehyde (102.67 μg/mg), as well as myeloperoxidase (12.29 U/mg) in colon tissue, were reduced as compared to the untreated group. Also, the body weight and colon weight/length ratios were more improved in the treated group with 400 mg/kg Aloe vera extract, rectally. Conclusion. Aloe vera extract exhibited a therapeutic effect in TNBS-induced colitis, and local, rectal administration of Aloe vera extract was more effective than oral administration.

Dendrobium officinale Polysaccharide Alleviates Intestinal Inflammation by Promoting Small Extracellular Vesicle Packaging of miR-433-3p

Dendrobium officinale polysaccharide (DOP) attenuates inflammatory bowel disease (IBD), but its role in regulating cross-talk between intestinal epithelial cells (IEC) and macrophages against IBD is unclear. This study aimed to investigate DOP protective effects on the intestinal inflammatory response through regulation by miRNA in small extracellular vesicles (sEVs). Our results show that DOP interfered with the secretion of small extracellular vesicles (DIEs) by IEC, which reduced the levels of inflammatory mediators. Increased miR-433-3p expression in DIEs was identified as an important protector against intestinal inflammation. DOP regulated the loading of miR-433-3p by hnRNPA2B1 into the intestinal sEV to increase the abundance of miR-433-3p. DIEs delivered miR-433-3p to lipopolysaccharide-induced macrophages and targeted the MAPK8 gene, leading to inhibition of the MAPK signaling pathway and reduced production of inflammatory cytokines. One protective mechanism of DOP is mediated by intestinal sEV containing miR-433-3p, which is a potential therapeutic agent for the prevention of inflammatory factor accumulation from excessive intestinal macrophage activity and for restoring homeostasis in the intestinal microenvironment.

The preventive effect and underlying mechanism of Rhus chinensis Mill. fruits on dextran sulphate sodium-induced ulcerative colitis in mice

The purpose of this research was to explore the preventive effect of an 80% ethanol extract of Rhus chinensis Mill. fruits on dextran sulfate sodium (DSS)-induced colitis in mice and to elucidate the underlying molecular mechanisms of this effect. The results indicated that the extract, especially when administered at a high dose, could dramatically decrease the disease activity index, maintain normal spleen conditions, and improve colonic histopathology and length in the DSS-induced mice. In addition, extract administration could significantly suppress the levels of malondialdehyde, myeloperoxidase, tumor necrosis factor-α, interleukin-1β, and interleukin-6 and enhance superoxide dismutase and glutathione levels. The extract obviously protected intestinal barrier integrity by improving Occludin, ZO-1 and Claudin-1 expression levels. Western blot and immunohistochemistry analyses further indicated that the preventive effect of the phenol-rich extract on DSS-induced colitis might be achieved through the up-regulation of the expression of several pivotal oxidative stress-associated proteins, namely Nrf2, NQO1 and HO-1, and the down-regulation of the expression of several pivotal inflammation-associated proteins, namely p-NF-κB, p-IκB, COX-2, iNOS, p-P38, p-Erk1/2, and p-JNK. Therefore, R. chinensis fruits extract possesses the capability to prevent DSS-induced ulcerative colitis in mice and could be utilized as a natural substance in the exploitation of functional foods as an adjuvant dietary therapy for preventing and/or alleviating inflammatory bowel disease.

Glucomannan from Aloe vera Gel Promotes Intestinal Stem Cell-Mediated Epithelial Regeneration via the Wnt/β-Catenin Pathway

Intestinal stem cells (ISCs) are essential to maintain intestinal epithelial regeneration and barrier function. Our previous work showed that glucomannan from Aloe vera gel (AGP) alleviated epithelial damage, but the mechanism was still elusive. Herein, RNA-sequencing analysis showed that proliferation and differentiation of intestinal epithelial cells as well as the canonical Wnt pathway were involved in this process. Further experiments exhibited that AGP promoted nuclear translocation of β-catenin and expression of transcription factor 7, increased the number of Lgr5⁺ ISCs, and differentiated epithelial cells in mice colon. Intriguingly, AGP reversed the inhibition of IEC-6 cells proliferation induced by an inhibitor of the canonical Wnt pathway. Hence, this study implied that AGP promoted proliferation and differentiation of colon stem cells via Wnt/β-catenin signaling, which subsequently facilitated the regeneration of epithelial cells and alleviated colitis in mice. It may provide new insights into the role of polysaccharides in regulating intestinal homeostasis and relieving intestinal injury.