Ulcerative colitis: Gut microbiota, immunopathogenesis and application of natural products in animal models

Anti-inflammatory Effects of Bacteroidota Strains Derived From Outstanding Donors of Fecal Microbiota Transplantation for the Treatment of Ulcerative Colitis

BACKGROUND

The proportion of certain Bacteroidota species decreased in patients with ulcerative colitis, and the recovery of Bacteroidota is associated with the efficacy of fecal microbiota transplantation therapy. We hypothesized that certain Bacteroidota may advance ulcerative colitis treatment. Accordingly, we aimed to evaluate the anti-inflammatory effects of Bacteroidota strains isolated from donors.

METHODS

Donors with proven efficacy of fecal microbiota transplantation for ulcerative colitis were selected, and Bacteroidota strains were isolated from their stools. The immune function of Bacteroidota isolates was evaluated through in vitro and in vivo studies.

RESULTS

Twenty-four Bacteroidota strains were isolated and identified. Using an in vitro interleukin (IL)-10 induction assay, we identified 4 Bacteroidota strains with remarkable IL-10-induction activity. Of these, an Alistipes putredinis strain exhibited anti-inflammatory effects in a mouse model of colitis induced by sodium dextran sulfate and oxazolone. However, 16S rRNA gene-based sequencing analysis of A. putredinis cultures in the in vivo study revealed unexpected Veillonella strain contamination. A second in vitro study confirmed that the coculture exhibited an even more potent IL-10-inducing activity. Furthermore, the production of A. putredinis-induced IL-10 was likely mediated via toll-like receptor 2 signaling.

CONCLUSIONS

This study demonstrated that A. putredinis, a representative Bacteroidota species, exhibits anti-inflammatory effects in vivo and in vitro; however, the effects of other Bacteroidota species remain unexplored. Our fecal microbiota transplantation-based reverse translation approach using promising bacterial species may represent a breakthrough in microbiome drug development for controlling dysbiosis during ulcerative colitis.

Poria cocos Attenuated DSS-Induced Ulcerative Colitis via NF-κB Signaling Pathway and Regulating Gut Microbiota

Ulcerative colitis (UC), as a chronic inflammatory disease, presents a global public health threat. However, the mechanism of Poria cocos (PC) in treating UC remains unclear. Here, LC-MS/MS was carried out to identify the components of PC. The protective effect of PC against UC was evaluated by disease activity index (DAI), colon length and histological analysis in dextran sulfate sodium (DSS)-induced UC mice. ELISA, qPCR, and Western blot tests were conducted to assess the inflammatory state. Western blotting and immunohistochemistry techniques were employed to evaluate the expression of tight junction proteins. The sequencing of 16S rRNA was utilized for the analysis of gut microbiota regulation. The results showed that a total of fifty-two nutrients and active components were identified in PC. After treatment, PC significantly alleviated UC-associated symptoms including body weight loss, shortened colon, an increase in DAI score, histopathologic lesions. PC also reduced the levels of inflammatory cytokines TNF-α, IL-6, and IL-1β, as evidenced by the suppressed NF-κB pathway, restored the tight junction proteins ZO-1 and Claudin-1 in the colon, and promoted the diversity and abundance of beneficial gut microbiota. Collectively, these findings suggest that PC ameliorates colitis symptoms through the reduction in NF-κB signaling activation to mitigate inflammatory damage, thus repairing the intestinal barrier, and regulating the gut microbiota.

MRGPRB2/X2 and the analogous effects of its agonist and antagonist in DSS-induced colitis in mice

The mast cell receptor Mrgprb2, a mouse orthologue of human Mrgprx2, is known as an inflammatory receptor and its elevated expression is associated with various diseases such as ulcerative colitis. We aimed to elucidate the role of Mrgprb2/x2 and the effect of its ligands on a chemically induced murine colitis model. We showed that in Mrgprb2-/- mice, there is a differential regulation of cytokine releases in the blood plasma and severe colonic damages after DSS treatment. Unexpectedly, we demonstrated that known Mrgprb2/x2 agonists (peptide P17, P17 analogues and CST-14) and antagonist (GE1111) similarly increased the survival rate of WT mice subjected to 4% DSS-induced colitis, ameliorated the colonic damages of 2.5% DSS-induced colitis, restored major protein mRNA expression involved in colon integrity, reduced CD68+ and F4/80+ immune cell infiltration and restored cytokine levels. Collectively, our findings highlight the eminent role of Mrpgrb2/x2 in conferring a beneficial effect in the colitis model, and this significance is demonstrated by the heightened severity of colitis with altered cytokine releases and inflammatory immune cell infiltration observed in the Mrgprb2 knockout mice. Elevated expression of Mrgprb2 in WT colitis murine models may represent the organism's adaptive protective mechanism since Mrgprb2 knockout results in severe colitis. On the other hand, both agonist and antagonist of Mrgprb2 analogously mitigated the severity of colitis in DSS-induced colitis model by altering Mrgprb2 expression, immune cell infiltration and inflammatory cytokine releases.

Grape seed proanthocyanidin extract alleviates inflammation in experimental colitis mice by inhibiting NF-κB signaling pathway

Ulcerative colitis (UC) is a complex inflammatory disease of colorectum that induces abnormal immune responses and severely affects the quality of life of the patients. Grape seed proanthocyanidin extract (GSPE) exerts anti-inflammatory and antioxidant functions in many inflammatory diseases. The objective of this study was to investigate the potential therapeutic effects and underlying mechanisms of GSPE in UC using a dextran sodium sulfate (DSS)-induced mouse UC model and a lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage model. In this study, we found that the GSPE markedly prevented DSS-induced weight loss and colon length shortening in UC mice. Further investigations showed that GSPE significantly attenuated the expression of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β, and elevated the expression of anti-inflammatory cytokine IL-10 in the colon tissues and serum of DSS-induced colitis mice by suppressing NF-κB signaling pathway. Furthermore, LPS-induced inflammation in RAW264.7 cells was also reversed by GSPE. Taken together, our results confirm that GSPE can ameliorate inflammatory response in experimental colitis via inhibiting NF-κB signaling pathway. This study advances the research progress on a potentially effective therapeutic strategy for inflammatory bowel diseases.

Ethanol Extract of Limonium bicolor Improves Dextran Sulfate Sodium-Induced Ulcerative Colitis by Alleviating Inflammation and Restoring Gut Microbiota Dysbiosis in Mice

Ulcerative colitis (UC) is a kind of inflammatory bowel condition characterized by inflammation within the mucous membrane, rectal bleeding, diarrhea, and pain experienced in the abdominal region. Existing medications for UC have limited treatment efficacy and primarily focus on symptom relief. Limonium bicolor (LB), an aquatic traditional Chinese medicine (TCM), exerts multi-targeted therapeutic effects with few side effects and is used to treat anemia and hemostasis. Nevertheless, the impact of LB on UC and its mechanism of action remain unclear. Therefore, the objective of this study was to investigate the anti-inflammatory effects and mechanism of action of ethanol extract of LB (LBE) in lipopolysaccharide-induced RAW 264.7 macrophages and dextran sulfate sodium (DSS)-induced UC. The results showed that LBE suppressed the secretion of cytokines in LPS-stimulated RAW 264.7 cells in a dose-dependent manner. LBE had protective effects against DSS-induced colitis in mice, decreased the disease activity index (DAI) score, alleviated symptoms, increased colon length, and improved histological characteristics, thus having protective effects against DSS-induced colitis in mice. In addition, it reversed disturbances in the abundance of proteobacteria and probiotics such as Lactobacillus and Blautia in mice with DSS-induced UC. Based on the results of network pharmacology analysis, we identified four main compounds in LBE that are associated with five inflammatory genes (Ptgs2, Plg, Ppar-γ, F2, and Gpr35). These results improve comprehension of the biological activity and functionality of LB and may facilitate the development of LB-based compounds for the treatment of UC.

Protective effects of sinomenine against dextran sulfate sodium-induced ulcerative colitis in rats via alteration of HO-1/Nrf2 and inflammatory pathway

BACKGROUND

Dextran Sulfate Sodium (DSS) induces ulcerative colitis (UC), a type of inflammatory bowel disease (IBD) that leads to inflammation, swelling, and ulcers in the large intestine. The aim of this experimental study is to examine how sinomenine, a plant-derived alkaloid, can prevent or reduce the damage caused by DSS in the colon and rectum of rats.

MATERIAL AND METHODS

Induction of ulcerative colitis (UC) in rats was achieved by orally administering a 2% Dextran Sulfate Sodium (DSS) solution, while the rats concurrently received oral administrations of sinomenine and sulfasalazine. The food, water intake was estimated. The body weight, disease activity index (DAI), colon length and spleen index estimated. Antioxidant, cytokines, inflammatory parameters and mRNA expression were estimated. The composition of gut microbiota was analyzed at both the phylum and genus levels in the fecal samples obtained from all groups of rats.

RESULTS

Sinomenine treatment enhanced the body weight, colon length and reduced the DAI, spleen index. Sinomenine treatment remarkably suppressed the level of NO, MPO, ICAM-1, and VCAM-1 along with alteration of antioxidant parameters such as SOD, CAT, GPx, GR and MDA. Sinomenine treatment also decreased the cytokines like TNF-α, IL-1, IL-1β, IL-6, IL-10, IL-17, IL-18 in the serum and colon tissue; inflammatory parameters viz., PAF, COX-2, PGE2, iNOS, NF-κB; matrix metalloproteinases level such as MMP-1 and MMP-2. Sinomenine significantly (P < 0.001) enhanced the level of HO-1 and Nrf2. Sinomenine altered the mRNA expression of RIP1, RIP3, DRP3, NLRP3, IL-1β, caspase-1 and IL-18. Sinomenine remarkably altered the relative abundance of gut microbiota like firmicutes, Bacteroidetes, F/B ratio, Verrucomicrobia, and Actinobacteria.

CONCLUSION

The results clearly indicate that sinomenine demonstrated a protective effect against DSS-induced inflammation, potentially through the modulation of inflammatory pathways and gut microbiota.

Isoliquiritigenin Containing PH Sensitive Micelles for Enhanced Anti-Colitis Activity

Isoliquiritigenin (ISL) is known to have a variety of pharmacological activities, but its poor water solubility limits its application. In order to improve the bioavailability of ISL and its anti-colitis activity, this study aims to develop an effective drug delivery system loaded with ISL. In this study, ISL pH-sensitive micelles (ISL-M) were prepared by thin film hydration method. The micellar size (PS), polydispersity index (PDI), electrokinetic potential (ζ-potential), drug loading (DL), encapsulation rate (EE) and other physical parameters were characterized. The storage stability of ISL-M was tested, release in vitro and pharmacokinetic studies in rats were performed, and the anti-inflammatory effect of ISL-M on ulcerative colitis induced by dextran sulfate sodium (DSS) was evaluated. The results showed that PS, PDI, ZP, EE% and DL% of ISL-M were 151.15±1.04 nm, 0.092±0.014, -31.32±0.721 mV, 93.97±1.53 % and 8.42±0.34 %, respectively. Compared with unformulated ISL (F-ISL), the cumulative release rate of ISL-M in the three different media was significantly increased and showed a certain pH sensitivity. The area under drug curve (AUC0-t) and peak concentration (Cmax) of ISL-M group were 2.94 and 4.06 times higher than those of ISL group. In addition, ISL-M is expected to develop new methods for increasing the bioavailability and anti-inflammatory activity of ISL.

Integrated Metabolomics and Gut Microbiome Analysis Reveals the Efficacy of a Phytochemical Constituent in the Management of Ulcerative Colitis

SCOPE

Cinnamaldehyde (CAH), a phytochemical constituent isolated from cinnamon, is gaining attention due to its nutritional and medicinal benefits. This study aimed to investigate the potential role of CAH in the treatment of ulcerative colitis (UC).

METHODS AND RESULTS

Integrated metabolomics and gut microbiome analysis are performed for 2,4,6-trinitrobenzenesulfonic acid (TNBS) induced UC rats. The effect of CAH on colonic inflammation, lipid peroxidation, metabolic profiles, and gut microbiota is systematically explored. It finds that CAH improves the colitis-related symptoms, decreases disease activity index, increases the colon length and body weight, and alleviates histologic inflammation of UC rats. These therapeutic effects of CAH are due to suppression of inflammation and lipid peroxidation. Moreover, multi-omics analysis reveals that CAH treatment cause changes in plasma metabolome and gut microbiome in UC rats. CAH regulates lipid metabolic processes, especially phosphatidylcholines, lysophosphatidylcholines, and polyunsaturated fatty acids. Meanwhile, CAH modulates the gut microbial structure by restraining pathogenic bacteria (such as Helicobacter) and increasing probiotic bacteria (such as Bifidobacterium and Lactobacillus).

CONCLUSIONS

These results indicate that CAH exerts a beneficial role in UC by synergistic modulating the balance in gut microbiota and the associated metabolites, and highlights the nutritional and medicinal value of CAH in UC management.

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.

Virofree Associates with the Modulation of Gut Microbiomes and Alleviation of DSS-Induced IBD Symptoms in Mice

Inflammatory bowel disease (IBD) is a chronic, nonspecific inflammation of the intestines that primarily comprises Crohn's disease and ulcerative colitis. The incidence and prevalence of IBD have been increasing globally, highlighting the significance of research and prophylactic interventions. Virofree, a mixture of various botanical extracts (including grapes, cherries, olive leaves, marigolds, green tea, and others), has shown significant potential in disease prevention. This study examined the effects of Virofree on intestinal inflammation and the gut microbiota in mice using a dextran sulfate sodium (DSS)-induced model. The mice showed no adverse reactions when administered Virofree. Virofree administration reduced the disease activity index as indicated by amelioration of DSS-induced symptoms in the mice, including weight loss, diarrhea, and rectal bleeding. Regarding the gut microbiota, Virofree intervention modulated the DSS-induced decrease in gut microbial diversity; the Virofree group showed no increase in the phyla Proteobacteria or Verrucomicrobia while displaying an increase in the genus Duncaniella, bacteria that may have protective properties. These findings suggest that Virofree may have a direct or indirect impact on the composition of the gut microbiota and that it can alleviate the imbalance of the microbiome and intestinal inflammation caused by DSS treatment.

Forsythia suspensa (Thunb.) Vahl extract ameliorates ulcerative colitis via inhibiting NLRP3 inflammasome activation through the TLR4/MyD88/NF-κB pathway

BACKGROUND

Ulcerative colitis (UC), a chronic inflammatory disease, is caused by abnormal immune system reactions resulting in inflammation and ulcers in the large intestine. Phillygenin (PHI) is a natural compound found in Forsythia suspensa (Thunb.) Vahl, which is known for its antipyretic, anti-inflammatory, antiobesity, and other biological activities. However, the therapeutic role and molecular mechanisms of PHI on UC are still insufficiently researched.

METHODS

In this study, dextran sulfate sodium (DSS) and 2.5% 2,4,6-trinitro-Benzenesulfonic acid (TNBS)-induced acute UC were used to investigate the therapeutic effects of PHI. We evaluated the effects of PHI on disease activity index (DAI), body weight, mortality, intestinal mucosal barrier, cytokine secretion, and macrophage infiltration into colon tissue using various techniques such as flow cytometry, immunofluorescence, enzyme-linked immunosorbent assay (ELISA), RT-qPCR, and Western blot analysis.

RESULTS

Our findings revealed that PHI has therapeutic properties in UC treatment. PHI was able to maintain body weight, reduce DAI and mortality, restore the intestinal mucosal barrier, and inhibit cytokine secretion. Flow cytometry assay and immunofluorescence indicated that PHI reduces macrophage infiltration into colon tissue. Mechanistically, PHI may exert anti-inflammatory effects by downregulating the TLR4/MyD88/NF-κB pathway and inhibiting the activation of NLRP3 inflammasome.

CONCLUSION

In conclusion, PHI possesses significant anti-inflammatory properties and is expected to be a potential drug for UC treatment. Our study delves into the underlying mechanisms of PHI therapy and highlights the potential for further research in developing PHI-based treatments for UC.

CPW partially attenuates DSS-induced ulcerative colitis in mice

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) of the gastrointestinal tract. The etiology is not fully understood, but environmental, microbial, and immunologic factors, as well as a genetic predisposition, play a role. UC is characterized by episodes of abdominal pain, diarrhea, bloody stools, weight loss, severe colonic inflammation, and ulceration. Despite the increase in the frequency of UC and the deterioration of the quality of life, there are still patients who do not respond well to available treatment options. Against this background, natural products such as polysaccharides are becoming increasingly important as they protect the intestinal mucosa, promote wound healing, relieve inflammation and pain, and restore intestinal motility. In this study, we investigated the effect of a polysaccharide isolated from the biomass of Campomanesia adamantium and Campomanesia pubescens (here referred to as CPW) in an experimental model of acute and chronic ulcerative colitis induced by dextran sulfate sodium (DSS). CPW reversed weight loss, increased disease activity index (DAI), bloody diarrhea, and colon shortening. In addition, CPW reduced visceral mechanical hypersensitivity, controlled oxidative stress and inflammation, and protected the mucosal barrier. CPW is not absorbed in the intestine, does not inhibit cytochrome P450 proteins, and does not exhibit AMES toxicity. These results suggest that CPW attenuates DSS-induced acute and chronic colitis in mice and may be a potential alternative treatment for UC.

Fecal microbiota transplantation combined with prebiotics ameliorates ulcerative colitis in mice

Aim: To investigate the effect of treatment with fecal microbiota transplantation (FMT) and galacto- and fructo-oligosaccharides on ulcerative colitis (UC) in mice. Materials & methods: A total of 90 mice, divided into nine groups, were administered FMT or prebiotics or combined treatment. The disease activity index scores, gut microbiota and inflammation factors were evaluated. Results: The treatment using FMT combined with galacto- and fructo-oligosaccharides in a 9:1 ratio significantly reduced intestinal barrier damage and alleviated symptoms of UC. Lactobacillus and Bifidobacterium and short-chain fatty acids were significantly increased after the combined treatment. Conclusion: The results demonstrate that FMT with prebiotics is a new method for UC treatment.

Mechanistic insights into the role of probiotics in modulating immune cells in ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a persistent inflammatory disorder that affects the gastrointestinal tract, mainly the colon, which is defined by inflammatory responses and the formation of ulcers. Probiotics have been shown to directly impact various immune cells, including dendritic cells (DCs), macrophages, natural killer (NK) cells, and T and B cells. By interacting with cell surface receptors, they regulate immune cell activity, produce metabolites that influence immune responses, and control the release of cytokines and chemokines.

METHODS

This article is a comprehensive review wherein we conducted an exhaustive search across published literature, utilizing reputable databases like PubMed and Web of Science. Our focus centered on pertinent keywords, such as "UC," 'DSS," "TNBS," "immune cells," and "inflammatory cytokines," to compile the most current insights regarding the therapeutic potential of probiotics in managing UC.

RESULTS

This overview aims to provide readers with a comprehensive understanding of the effects of probiotics on immune cells in relation to UC. Probiotics have a crucial role in promoting the proliferation of regulatory T cells (Tregs), which are necessary for preserving immunological homeostasis and regulating inflammatory responses. They also decrease the activation of pro-inflammatory cells like T helper 1 (Th1) and Th17 cells, contributing to UC development. Thus, probiotics significantly impact both direct and indirect pathways of immune cell regulation in UC, promoting Treg differentiation, inhibiting pro-inflammatory cell activation, and regulating cytokine and chemokine release.

CONCLUSION

Probiotics demonstrate significant potential in modulating the immune reactions in UC. Their capacity to modulate different immune cells and inflammation-related processes makes them a promising therapeutic approach for managing UC. However, further studies are warranted to optimize their use and fully elucidate the molecular mechanisms underlying their beneficial effects in UC treatment.

LncRNA MIR4435-2HG suppression regulates macrophage M1/M2 polarization and reduces intestinal inflammation in mice with ulcerative colitis

OBJECTIVE

To explore the effect and potential mechanism of LncRNA MIR4435-2HG on macrophage polarization and intestinal inflammation in ulcerative colitis (UC). Methods RAW264.7 macrophage cells stimulated with lipopolysaccharide (LPS) were co-cultured with Caco-2 cells to establish an inflammatory model of UC in vitro. Balb/c mice were orally administered dextran sulfate sodium (DSS) to establish an in vivo UC model. Flow cytometry and immunohistochemical (IHC) analyses were performed to assess the levels of surface phenotype markers. RT-qPCR and enzyme-linked immunosorbent assay (ELISA) were performed to measure the levels of inflammatory cytokines. Western blotting was used to analyze expression of the tight junction protein zona occludens 1 (ZO-1) and the key proteins of the JAK1/STAT1 signaling pathway (Janus kinase-1(JAK1), p-JAK1, signal transducer and activator of transcription 1 (STAT1), p-STAT1. Results In in vitro experiments, we found that inhibition of MIR4435-2HG was able to decrease the levels of CD68, iNOS, IL-6, and TEER, and increase the levels of CD206, Arg-1, IGF-1, and ZO-1. Meanwhile, inhibition of MIR4435-2HG significantly suppressed the levels of p- JAK1 and p- STAT1. In addition, we further demonstrated by in vivo experiments that inhibition of MIR4435-2HG significantly attenuated intestinal inflammation in mice, as evidenced by increased body weight, increased colon length and weight, decreased fecal scores, hemorrhagic scores, and DAI scores, and amelioration of colonic injury, and decreased inflammatory factors. Conclusions MIR4435-2HG suppression inhibits macrophage M1 polarization while promoting M2 polarization, thereby alleviating intestinal inflammation in mice with ulcerative colitis through JAK1/STAT1 signaling.

N-Acetylglucosamine and its dimer ameliorate inflammation in murine colitis by strengthening the gut barrier function

Ulcerative colitis (UC) is a chronic gastrointestinal disease whose incidence is increasing rapidly worldwide. Anti-inflammatory medications, including 5-aminosalicylic acid (5-ASA), corticosteroids, and immunosuppressants, are used for its treatment; however, new alternatives would be required due to the serious side effects of some of these medications. N-Acetylglucosamine (NAG) is an amino sugar composed of mucin that is secreted by intestinal epithelial cells. It is also used to promote the growth of intestinal bacteria. The current study aimed to determine the efficacy of NAG against dextran sulfate sodium (DSS)-induced chronic colitis and elucidate its mechanism of action. Mice were randomly divided into control, DSS, 0.1% sulfasalazine, 0.1% NAG, 0.3% NAG, and 0.3% NAG-dimer (NAG-D) groups, and results showed that colitis-induced body weight loss, disease activity, colonic tissue damage, colon length shortening, and the loss of mucin-secreting area were significantly improved in the NAG-D group. The intestinal permeability indicator, serum CD 14 level, and expression of the tight junction protein, occludin, were both improved in the 0.3% NAG group. Inflammatory biomarkers, including GATA3, IFN-γ, p-IκBα, COX2, TGF-β1, and Smad7, were significantly lower in the 0.3% NAG and NAG-D groups than in the DSS group. The intestinal microbial composition was most significantly altered in the 0.3% NAG group, showing decreased ratios of pathogenic bacteria, such as Betaproteobacteria, especially Burkholderiales. The results overall suggested that NAG or NAG-D supplementation can alleviate inflammation by strengthening the intestinal barrier function and maintaining gut microbiota homeostasis in a DSS-induced colitis mouse model.

In-vitro and in-vivo evaluation and anti-colitis activity of esculetin-loaded nanostructured lipid carrier decorated with DSPE-MPEG2000

OBJECTIVE

Encapsulation of esculetin into DSPE-MPEG2000 carrier was performed to improve its water solubility and oral bioavailability, as well as enhance its anti-inflammatory effect on a mouse model of ulcerative colitis that was induced with dextran sulphate sodium (DSS).

METHODS

We determined the in-vitro and in-vivo high-performance liquid chromatographic (HPLC) analysis method of esculetin; Esculetin-loaded nanostructure lipid carrier (Esc-NLC) was prepared using a thin-film dispersion method, wherein a particle size analyser was used to measure the particle size (PS) and zeta potential (ZP) of the Esc-NLC, while a transmission electron microscope (TEM) was employed to observe its morphology. Also, HPLC was used to measure its drug loading (DL), encapsulation efficiency (EE) and the in-vitro release of the preparation, as well as investigate the pharmacokinetic parameters. In addition, its anti-colitis effect was evaluated via histopathological examination of HE-stained sections and detection of the concentrations of tumour necrosis factor-alpha (TNF-α), interleukin (IL)-1 beta (β), and IL-6 in serum with ELISA kits.

RESULTS

The PS of Esc-NLC was 102.29 ± 0.63 nm with relative standard deviation (RSD) of 1.08% (with poly-dispersity index-PDI of 0.197 ± 0.023), while the ZP was -15.67 ± 1.39 mV with RSD of 1.24%. Solubility of esculetin was improved coupled with prolonged release time. Its pharmacokinetic parameters were compared with that of free esculetin, wherein the maximum concentration of the drug in plasma was increased by 5.5 times. Of note, bioavailability of the drug was increased by 1.7 times, while the half-life was prolonged by 2.4 times. In the anti-colitis efficacy experiment, the mice in Esc and Esc-NLC groups exhibited significantly reduced levels of TNF-α, IL-1β, and IL-6 in their sera comparable to the DSS group. Colon histopathological examination revealed that mice with ulcerative colitis in both Esc and Esc-NLC groups displayed improved inflammation, amid the Esc-NLC groups having the best prophylactic treatment effect.

CONCLUSION

Esc-NLC could ameliorate DSS-induced ulcerative colitis by improving bioavailability, prolonging drug release time and regulating cytokine release. This observation confirmed the potential of Esc-NLC to reduce inflammation in ulcerative colitis, albeit the need for follow-up research to verify the application of this strategy to clinical treatment of ulcerative colitis.

The gut microbes in inflammatory bowel disease: Future novel target option for pharmacotherapy

Gut microbes constitute the main microbiota in the human body, which can regulate biological processes such as immunity, cell proliferation, and differentiation, hence playing a specific function in intestinal diseases. In recent years, gut microbes have become a research hotspot in the pharmaceutical field. Because of their enormous number, diversity, and functional complexity, gut microbes have essential functions in the development of many digestive diseases. Inflammatory bowel disease (IBD) is a chronic non-specific inflammatory disease with a complex etiology, the exact cause and pathogenesis are unclear. There are no medicines that can cure IBD, and more research on therapeutic drugs is urgently needed. It has been reported that gut microbes play a critical role in pathogenesis, and there is a tight and complex association between gut microbes and IBD. The dysregulation of gut microbes may be a predisposing factor for IBD, and at the same time, IBD may exacerbate gut microbes' disorders, but the mechanism of interaction between the two is still not well defined. The study of the relationship between gut microbes and IBD is not only important to elucidate the pathogenesis but also has a positive effect on the treatment based on the regimen of regulating gut microbes. This review describes the latest research progress on the functions of gut microbes and their relationship with IBD, which can provide reference and assistance for further research. It may provide a theoretical basis for the application of probiotics, fecal microbiota transplantation, and other therapeutic methods to regulate gut microbes in IBD.

Garlic-derived exosome-like nanovesicles alleviate dextran sulphate sodium-induced mouse colitis via the TLR4/MyD88/NF-κB pathway and gut microbiota modulation

Plant-derived exosome-like nanovesicles play an important role in transferring their biological cargos to recipient cells. The effect of garlic-derived exosome-like nanovesicles (GENs) against inflammatory bowel disease (IBD) remains unknown. This study aimed to investigate the effect of GENs on dextran sulphate sodium (DSS)-induced colitis in mice. A comprehensive analysis of bioactive components in GENs was performed. Data showed that GENs contained 26 lipids, 61 proteins and 127 known microRNAs (miRNAs). Han-miR3630-5p in GENs could bind to the 3' untranslated region of toll-like receptor 4 (TLR4), which led to the inhibition of TLR4 expression. Besides, GENs significantly up-regulated the expression of barrier-related proteins and inhibited the overproduction of pro-inflammatory cytokines in LPS-induced Caco-2 cells. As a result, pretreatment with GENs at 100 mg kg-1 efficiently ameliorated the inflammatory bowel behavior, intestinal histological pathological damage, and tight junction protein dysfunction induced by DSS in the colon tissue. Intake of GENs significantly down-regulated the expressions of TLR4, myeloid differentiation primary response gene 88 (MyD88), and nuclear factor kappa-B (NF-κB), which suppressed the downstream cascades and led to less secretion of pro-inflammatory cytokines induced by DSS. Furthermore, pretreatment with GENs altered the gut microbiota profile of colitis mice by recovering the relative abundance of Lachnospiraceae and reducing the relative abundance of Helicobacter. Totally, GENs had potential to protect the colon against DSS-induced damage through inhibiting the TLR4/MyD88/NF-κB signaling pathway and regulating gut microbiota. This study clarified the role of miRNAs of GENs in anti-colitis and proved that GENs had a potential application for IBD prevention.

Unraveling the Impact of Gut and Oral Microbiome on Gut Health in Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD) is a complex disorder characterized by chronic inflammation of the gastrointestinal tract (GIT). IBD mainly includes two distinct diseases, namely Crohn's disease and ulcerative colitis. To date, the precise etiology of these conditions is not fully elucidated. Recent research has shed light on the significant role of the oral and gut microbiome in the development and progression of IBD and its collective influence on gut health. This review aims to investigate the connection between the oral and gut microbiome in the context of IBD, exploring the intricate interplay between these microbial communities and their impact on overall gut health. Recent advances in microbiome research have revealed a compelling link between the oral and gut microbiome, highlighting their pivotal role in maintaining overall health. The oral cavity and GIT are two interconnected ecosystems that harbor complex microbial communities implicated in IBD pathogenesis in several ways. Reduction in diversity and abundance of beneficial bacterial species with the colonization of opportunistic pathogens can induce gut inflammation. Some of these pathogens can arise from oral origin, especially in patients with oral diseases such as periodontitis. It is essential to discern the mechanisms of microbial transmission, the impact of oral health on the gut microbiome, and the potential role of dysbiosis in disease development. By elucidating this relationship, we can enhance our understanding of IBD pathogenesis and identify potential therapeutic avenues for managing the disease. Furthermore, innovative strategies for modulating the oral and gut microbiome can promote health and prevent disease occurrence and progression.

Anti-Inflammatory and Gut Microbiota Modulation Potentials of Flavonoids Extracted from Passiflora foetida Fruits

This study aimed to explore the anti-inflammatory and gut microbiota modulation potentials of flavonoid-rich fraction (PFF) extracted from Passiflora foetida fruits. The results showed that PFF markedly reduced the production of nitric oxide (NO), tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6) in LPS-stimulated RAW 264.7 cells. Meanwhile, PFF treatment also effectively decreased the phosphorylation levels of MAPK, PI3K/Akt, and NF-κB signaling-pathway-related proteins (ERK, JNK, p38, Akt, and p65). Moreover, PFF had an impact on microbial composition and metabolites in a four-stage dynamic simulator of human gut microbiota (BFBL gut model). Specifically, PFF exhibited the growth-promoting ability of several beneficial bacteria, including Bifidobacterium, Enterococcus, Lactobacillus, and Roseburia, and short-chain fatty acid (SCFA) generation ability in gut microbiota. In addition, spectroscopic data revealed that PFF mainly contained five flavonoid compounds, which may be bioactive compounds with anti-inflammatory and gut microbiota modulation potentials. Therefore, PFF could be utilized as a natural anti-inflammatory agent or supplement to health products.

Protective Effects of Different Molecular Weights of Purslane (Portulaca oleracea L.) Aqueous Extract on DSS-Induced Ulcerative Colitis in Mice

Purslane, a common wild vegetable, contains active substances with various biological functions. However, its effects have been under-investigated in ulcerative colitis (UC). Therefore, this study investigated the therapeutic effects of purslane macromolecular (POEM) and small molecular extracts (POES) on dextran sulfate sodium (DSS)-induced UC in mice. Membrane separation was used to obtain extracts of different molecular weights, and their compositional differences were compared using liquid chromatography-mass spectrometry (LC/MS). POEM contained more proteins and polysaccharides, whereas POES contained more organic acids and alkaloids. These differences in composition were directly responsible for the different degrees of remission of the alleviated UC in model mice. POEM may alleviate UC by regulating the antioxidant capacity and the gut microbiota, whereas the major alleviatory effect of POES was primarily related to the regulation of antioxidant capacity. The POEM and POES effects identified in this study provide a theoretical basis for the development of purslane as a functional food.

Effects of Amazake Produced with Different Aspergillus on Gut Barrier and Microbiota

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract. To explore the preventive effects of dietary foods on IBD, we evaluated the effects of the traditional Japanese fermented beverage "Amazake" on gut barrier function in this study. Black koji Amazake (BA) derived from Aspergillus luchuensis MEM-C strain and yellow koji Amazake (YA) derived from Aspergillus oryzae were made in this study, and their nutrients were analyzed. Mice with mild gut barrier dysfunction induced by Western diet were administered with 10% of each Amazake for two months. Mice gut microbiota were analyzed by 16S rRNA gene sequencing. BA contained a higher amount of isomaltooligosaccharides, citric acid, and ferulic acid than YA. The animal data revealed that BA significantly induced the expressions of antioxidant factors and enzymes such as NF-E2-related factor 2 (Nfr2), heme oxygenase 1 (HO1), and superoxide dismutase-2 (SOD-2). The gut barrier protein, occludin, and fecal immunoglobulin A (IgA) were also significantly enhanced by BA. Furthermore, the levels of serum endotoxin and hepatic monocyte chemotactic protein-1 (MCP-1) were decreased in both the BA and YA groups. In gut microbiota, Lachnospiraceae was increased by BA while Akkermansia muciniphilia was increased by YA. Black koji Amazake contained a higher amount of isomaltooligosaccharides, citric acid, and ferulic acid than yellow koji Amazake and contributed to protecting gut barrier function to reduce endotoxin intrusion and inflammation.

Three acidic polysaccharides derived from sour jujube seeds protect intestinal epithelial barrier function in LPS induced Caco-2 cell inflammation model

Normal intestinal epithelial barrier function plays a key role in the prevention of many diseases such as infectious enteritis, inflammatory bowel disease, obesity, etc. In this study, three novel acidic polysaccharides ZY-2, ZY-3 and ZY-4 were isolated from sour jujube (Ziziphus jujuba Mill. var. Spinosa) seeds and purified by DEAE Sephrose Fast Flow gel. The molecular weight of ZY-2, ZY-3 and ZY-4 was 7.76 kDa, 10.71 kDa and 8.31 kDa respectively, mainly composed of different proportions of mannose, rhamnose, glucose, glucuronic acid, galacturonic acid, galactose, xylose and arabinose. ¹H NMR and Congo red experiment results showed that the three polysaccharides mainly contained both α-type and β-type glycosidic bonds with obvious triple helix structural traits. The polysaccharides could up-regulate the expression levels of occludin and ZO-1 in LPS-induced inflammation Caco-2 cells, and reduce IL-6, IL-8, IL-1β and TNF-α significantly. In conclusion, the acidic polysaccharides from sour jujube seeds exhibited great potential in protection intestinal epithelial barrier function through anti-inflammatory effects.

The effect of herbal medicine in innate immunity to Candida albicans

Candida albicans (C. albicans) is an opportunistic pathogenic fungus that often causes mucosal and systemic infections. Several pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) and C-type lectin receptors (CLRs), have been implicated in the host recognition of C. albicans. These PRRs recognize the pathogen-associated molecular patterns (PAMPs) of C. albicans to activate innate immune cells, thereby rapidly inducing various inflammatory responses by activating intracellular signaling cascades. Herbal medicine and its active components deserve priority development due to their low toxicity and high antibacterial, antiviral and antifungal activities. This review discussed the activities of herbal compounds against C. albicans and their related mechanisms, especially their regulatory role on innate immune cells such as neutrophils, macrophages, and dendritic cells (DCs) implicated in C. albicans infections. Our work aims to find new therapeutic drugs and targets to prevent and treat diseases caused by C. albicans infection with the mechanisms by which this fungus interacts with the innate immune response.

Anti-Inflammatory and Gut Microbiota Modulating Effects of Probiotic Lactobacillus paracasei MSMC39-1 on Dextran Sulfate Sodium-Induced Colitis in Rats

Probiotics have been shown to possess several properties, depending on the strain. Some probiotics have important roles in preventing infection and balancing the immune system due to the interaction between the intestinal mucosa and cells in the immune system. This study aimed to examine the properties of three probiotic strains using the tumor necrosis factor-alpha (TNF-α) inhibition test in colorectal adenocarcinoma cells (Caco-2 cells). It was revealed that the viable cells and heat-killed cells of the probiotic L. paracasei strain MSMC39-1 dramatically suppressed TNF-α secretion in Caco-2 cells. The strongest strains were then chosen to treat rats with colitis induced by dextran sulfate sodium (DSS). Viable cells of the probiotic L. paracasei strain MSMC39-1 reduced aspartate transaminase and alanine transaminase in the serum and significantly inhibited TNF-α secretion in the colon and liver tissues. Treatment with the probiotic L. paracasei strain MSMC39-1 alleviated the colon and liver histopathology in DSS-induced colitis rats. Furthermore, supplementation with probiotic L. paracasei strain MSMC39-1 increased the genus Lactobacillus and boosted the other beneficial bacteria in the gut. Thus, the probiotic L. paracasei strain MSMC39-1 exhibited an anti-inflammation effect in the colon and modulated the gut microbiota.

Hydroxysafflor yellow A protects against colitis in mice by suppressing pyroptosis via inhibiting HK1/NLRP3/GSDMD and modulating gut microbiota

Hydroxysafflor yellow A (HSYA), a chalcone glycoside, is a component of Carthamus tinctorius L. and exerts anti-inflammatory and antioxidative effects. However, the therapeutic effect and the underlying mechanism of HSYA on ulcerative colitis is unclear. This study aimed to investigate the unexplored protective effects and underlying mechanisms of HSYA on UC. In vitro analyses showed that HSYA reduced the secretion of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and IL-6 and inhibited nucleotide-binding and oligomerization domain-like receptor protein 3 (NLRP3)/gasdermin D (GSDMD)-mediated pyroptosis in lipopolysaccharide/ adenosine-5'-triphosphate (LPS/ATP)-stimulated macrophages. Gas chromatography-mass spectrometry (GC-MS) profiling of intracellular metabolites showed that HSYA reduced the increased levels of glucose, glucose 6-phosphate, and lactic acid, and inhibited the increased hexokinase 1 (HK1) expression caused by LPS/ATP stimulation. HK1 shRNA transfection further confirmed that HSYA inhibited the NLRP3/GSDMD-mediated pyroptosis via HK1 downregulation. In vivo analyses showed that HSYA drastically attenuated UC symptoms by relieving body weight loss, a decline in colon length, and inflammatory infiltration in colonic tissues induced by dextran sulfate sodium (DSS). HSYA also reduced the secretion of pro-inflammatory cytokines including IL-1β, IL-6, TNF-α, and IL-18. Moreover, HSYA inhibited HK1/NLRP3/GSDMD-mediated pyroptosis in DSS-induced colitis mice. Finally, 16S rRNA sequencing analyses of gut microbiota revealed that HSYA reversed gut microbiota dysbiosis by reducing the abundance of Proteobacteria and increasing that of Bacteroidetes. This study demonstrated that HSYA not only exerted anti-inflammatory effects by inhibiting HK1/NLRP3/GSDMD and suppressing pyroptosis but also regulated gut microbiota in mice with DSS-induced colitis. Our findings provide new experimental evidence that HSYA might be a potential candidate for treating inflammatory bowel diseases.

Treatment Effects of Natural Products on Inflammatory Bowel Disease In Vivo and Their Mechanisms: Based on Animal Experiments

Inflammatory bowel disease (IBD) is a chronic, non-specific inflammatory disease of the intestine that can be classified as ulcerative colitis (UC) and Crohn's disease (CD). Currently, the incidence of IBD is still increasing in developing countries. However, current treatments for IBD have limitations and do not fully meet the needs of patients. There is a growing demand for new, safe, and highly effective alternative drugs for IBD patients. Natural products (NPs) are used in drug development and disease treatment because of their broad biological activity, low toxicity, and low side effects. Numerous studies have shown that some NPs have strong therapeutic effects on IBD. In this paper, we first reviewed the pathogenesis of IBD as well as current therapeutic approaches and drugs. Further, we summarized the therapeutic effects of 170 different sources of NPs on IBD and generalized their modes of action and therapeutic effects. Finally, we analyzed the potential mechanisms of NPs for the treatment of IBD. The aim of our review is to provide a systematic and credible summary, thus supporting the research on NPs for the treatment of IBD and providing a theoretical basis for the development and application of NPs in drugs and functional foods.

Combination Therapy with Indigo and Indirubin for Ulcerative Colitis via Reinforcing Intestinal Barrier Function

Indigo and indirubin, the active molecules of traditional Chinese medicine indigo naturalis, exert therapeutic activity for ulcerative colitis (UC). Indigo and indirubin are isomers and have distinctive profiles in anti-inflammation, immune regulation, intestinal microbiota regulation, oxidative stress regulation, and intestinal mucosal repair for UC treatment. Thus, exploring its combined administration's integrated advantages for UC is critical. This study is aimed at clarifying the effect and mechanisms of the combined administration of indigo and indirubin on colitis mouse models. The results showed that all the treatment groups could improve the disease symptoms, and the combined administration showed the best effect. Additionally, compared with indigo and indirubin alone, the combination group could significantly reinforce intestinal barrier function by increasing the expression of E-cadherin, occludin, ZO-1, and MUC2 and improving intestinal permeability. The treatment groups significantly improved the expression of cytokines, including TNF-α, IFN-γ, IL-12, IL-23, and IL-17A, and indirubin presented the most potent anti-inflammatory effect. Furthermore, all the treatment groups reduced the infiltration of the immune cells in intestinal lamina propria and the production of ROS/RNS. Notably, indigo exhibited a more substantial capacity to regulate natural killer (NK) cells, ILC3, neutrophils, and dendritic cells, followed by the combination group and indirubin alone. Finally, all the treatment groups modulated intestinal microbiota composition, increased the proportion of beneficial microbiota, and decreased the proportion of microbiota. Our results indicated that indigo and indirubin synergistically reinforced the intestinal barrier function, which may be associated with integrating the indirubin anti-inflammatory and intestinal microbiota regulating strength and indigo immune and ROS/RNS regulation advantage.

The role and mechanism of flavonoid herbal natural products in ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory disease of the intestine that presents clinically with abdominal pain, mucopurulent stools, and posterior urgency. The lesions of UC are mainly concentrated in the rectal and colonic mucosa and submucosa. For patients with mild to moderate UC, the best pharmacological treatment includes glucocorticoids, immunosuppressants, antibiotics, and biologics, but the long-term application can have serious toxic side effects. Currently, nearly 40% of UC patients are treated with herbal natural products in combination with traditional medications to reduce the incidence of toxic side effects. Flavonoid herbal natural products are the most widely distributed polyphenols in plants and fruits, which have certain antioxidant and anti-inflammatory activities. Flavonoid herbal natural products have achieved remarkable efficacy in the treatment of UC. The pharmacological mechanisms are related to anti-inflammation, promotion of mucosal healing, maintenance of intestinal immune homeostasis, and regulation of intestinal flora. In this paper, we summarize the flavonoid components of anti-ulcerative colitis and their mechanisms reported in the past 10 years, to provide a basis for rational clinical use and the development of new anti-ulcerative colitis drugs.

Phillygenin Attenuated Colon Inflammation and Improved Intestinal Mucosal Barrier in DSS-induced Colitis Mice via TLR4/Src Mediated MAPK and NF-κB Signaling Pathways

Ulcerative colitis (UC) is a chronic, relapsing, and nonspecific inflammatory bowel disease (IBD). Phillygenin (PHI), a natural bioactive ingredient, isolated from Forsythiae Fructus, exhibits anti-inflammatory, anti-oxidative, and hepatoprotective activities. However, few reports provide direct evidence on the efficacy of PHI in improving colitis mice. The present study elucidated that the symptoms of DSS-induced colitis mice were alleviated after PHI administration, including body weight loss, the disease activity index, colon length shortening, colonic pathological damage, splenomegaly, and hepatomegaly. PHI treatment improved the intestinal mucosal barrier by protecting goblet cells, promoting gene expressions of Clca1, Slc26a3, and Aqp8, increasing tight junction proteins (TJs), and reducing epithelial cell apoptosis. In addition, the levels of oxidative stress (MPO, SOD, and MDA) and inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-10) were reversed by PHI in colitis mice. According to transcriptome and network pharmacology analysis, inflammatory pathway might be an important mechanism for PHI to improve colitis. Western blotting displayed that the PHI inhibited the activation of tyrosine kinase Src mediated by TLR4, and then reduced the phosphorylation of downstream proteins p38, JNK, and NF-κB in colitis mice. In summary, our results suggested that PHI might be an appropriate and effective drug candidate to protect colitis.

Colitis aggravated by Mrgprb2 knockout is associated with altered immune response, intestinal barrier function and gut microbiota

NEW FINDINGS

What is the central question of this study? What is the role of mas-related G protein-coupled receptor X2 (MRGPRX2/Mrgprb2) in ulcerative colitis in relation to the intestinal flora, intestinal barrier and immune response? What is the main finding and its importance? Knockout of mouse Mrgprb2 aggravates dextran sulfate sodium (DSS)-induced colitis, which is associated with altered gut microbiota and immune response and disruption of the intestinal barrier. MRGPRB2 may have a protective effect on DSS-induced colitis.

ABSTRACT

Ulcerative colitis (UC) is a chronic immune-related disease, and changes in the intestinal microbiota and damage to the intestinal barrier contribute to its pathogenesis. Mast cells (MCs) are widely distributed in the gastrointestinal tract and are thought to be related to the pathogenesis of UC. Human mas-related G protein-coupled receptor X2 (MRGPRX2) and its mouse homologue, Mrgprb2, are selectively expressed on MCs to recruit immune cells and modulate host defence against microbial infection. To investigate the role of Mrgprb2 in UC in mice, we compared the differences between Mrgprb2 knockout (b2KO) male mice and wild-type (WT) male mice with dextran sulfate sodium (DSS)-induced colitis in the severity of clinical symptoms, inflammatory cell infiltration, degree of intestinal barrier damage and composition of the intestinal flora. The results showed that weight loss, disease activity index score, colon shortening and colonic pathological damage were significantly increased in b2KO mice while MC activation, cytokine and chemokine secretion, and inflammatory cell infiltration were decreased. In addition, the abundance and diversity of the intestinal microbiota were reduced in b2KO mice. B2KO mice also exhibited a reduction of probiotics such as norank_f_Muribaculaceae and Lactobacillus and increase of harmful bacteria like Escherichia-Shigella. Intestinal mucosal barrier damage of b2KO mice was more severe than that of WT mice due to the attenuated expression of mucin-2 and occludin. These results demonstrated that MRGPRB2 may have a protective effect on DSS-induced colitis by altering the intestinal flora, participating in barrier repair and recruiting inflammatory cells to eliminate pathogens.

Potential of natural flavonols and flavanones in the treatment of ulcerative colitis

Ulcerative colitis (UC) is an inflammatory bowel disease generally characterized by chronic, persistent, recurrent, and non-specific ulcers of the intestine. Its main clinical manifestations include abdominal pain, diarrhea, and bloody stools. This disease is difficult to cure and even carries the risk of canceration. It has been listed as a modern refractory disease by the World Health Organization. Though a large amount of drugs are available for the inhibition of UC, the conventional treatment such as aminosalicylic acids, glucocorticoids, immunosuppressors, and biological agents possess certain limitations and serious side effects. Therefore, it is urgently needed for safe and effective drugs of UC, and natural-derived flavonols and flavanones showed tremendous potential. The present study concentrated on the progress of natural-derived flavonols and flavanones from edible and pharmaceutical plants for the remedy of UC over the last two decades. The potential pharmaceutical of natural-derived flavonols and flavanones against UC were closely connected with the modulation of gut microflora, gut barrier function, inflammatory reactions, oxidative stress, and apoptosis. The excellent efficacy and safety of natural flavonols and flavanones make them prospective drug candidates for UC suppression.

Pectic polysaccharides derived from Hainan Rauwolfia ameliorate NLR family pyrin domain-containing 3-mediated colonic epithelial cell pyroptosis in ulcerative colitis

Pectic polysaccharides (PPs) could exert functions on ulcerative colitis (UC), which is classified as a nonspecific inflammatory disorder. This study investigated the molecular mechanism of PPs derived from Rauwolfia in UC. First, the dextran sodium sulfate (DSS)-induced mouse colitis models and lipopolysaccharide (LPS)-treated colonic epithelial cell (YAMC) models were established and treated with PP. Subsequently, the effects of PPs on mucosal damages in DSS mice were detected, and the levels of inflammatory cytokines, pyroptosis-related factors, oxidative stress-related markers, and the tight junction-related proteins in the tissues or cells were examined, and the results suggested that PPs ameliorated colonic mucosal damages and cell pyroptosis in DSS mice, and limited colonic epithelial cell pyroptosis in in vitro UC models. Subsequently, the binding relations of retinol-binding protein 4 (RBP4) to miR-124-3p and NLR pyrin domain-containing 3 (NLRP3) were analyzed. miR-124-3p targeted RBP4 and reduced the binding of RBP4 to NLRP3, thus inhibiting NLRP3-mediated pyroptosis. Finally, functional rescue experiments revealed that miR-124-3p suppression or RBP4 overexpression promoted colonic epithelial cell pyroptosis. Collectively, Rauwolfia-derived PPs limited miR-124-3p and targeted RBP4 and reduced the binding potency of RBP4 to NLRP3 to inhibit NLRP3-mediated pyroptosis, resulting in the alleviation of colonic epithelial cell pyroptosis and mucosal damages in UC.

Premorbid Steatohepatitis Increases the Seriousness of Dextran Sulfate Sodium-induced Ulcerative Colitis in Mice

BACKGROUND AND AIMS

The concurrence of nonalcoholic steatohepatitis (NASH) and ulcerative colitis (UC) is increasingly seen in clinical practice, but the underlying mechanisms remain unclear. This study aimed to develop a mouse model of the phenomenon by combining high-fat high-cholesterol diet (HFHCD)-induced NASH and dextran sulfate sodium (DSS)-induced UC, that would support mechanistic studies.

METHODS

Male C57BL/6 mice were randomly assigned to two groups receiving either a chow diet or HFHCD for 12 weeks of NASH modeling. The mice were the divided into four subgroups for UC modeling: (1) A control group given a chow diet with normal drinking water; (2) A colitis group given chow diet with 2% DSS in drinking water; (3) A steatohepatitis group given HFHCD with normal drinking water; and (4) A steatohepatitis + colitis group given HFHCD with 2% DSS in drinking water.

RESULTS

NASH plus UC had high mortality (58.3%). Neither NASH nor UC alone were fatal. Although DSS-induced colitis did not exacerbate histological liver injury in HFHCD-fed mice, premorbid NASH significantly increased UC-related gut injury compared with UC alone. It was characterized by a significantly shorter colon, more colonic congestion, and a higher histopathological score (p<0.05). Inflammatory (tumor necrosis factor-alpha, interleukin 1 beta, C-C motif chemokine ligand 2, and nuclear factor kappa B) and apoptotic (Bcl2, Bad, Bim, and Bax) signaling pathways were significantly altered in distal colon tissues collected from mice with steatohepatitis + colitis compared with the other experimental groups.

CONCLUSIONS

Premorbid steatohepatitis significantly aggravated DSS-induced colitis and brought about a lethal phenotype. Potential links between NASH and UC pathogeneses can be investigated using this model.

Bifidobacterium bifidum H3-R2 and Its Molecular Communication within the Context of Ulcerative Colitis

Bifidobacteria are important mediators of immune system development within the gastrointestinal system and immunological homeostasis. The present study explored the anti-colitic activity of Bifidobacterium bifidum H3-R2 in a murine dextran sulfate sodium (DSS)-induced model of ulcerative colitis (UC). Moreover, this study offers novel insight regarding the molecular basis for the probiotic properties of B. bifidum H3-R2 by analyzing the underlying mechanisms whereby B. bifidum H3-R2-derived proteins affect the intestinal barrier. B. bifidum H3-R2 administration was sufficient to alleviate clinical manifestations consistent with DSS-induced colitis, restoring aberrant inflammatory cytokine production, enhancing tight junction protein expression, and positively impacting overall intestinal microecological homeostasis in these animals. Moreover, the bifidobacteria-derived GroEL and transaldolase (TAL) proteins were found to regulate tight junction protein expression via the NF-κB, myosin light chain kinase (MLCK), RhoA/Rho-associated protein kinase (ROCK), and mitogen-activated protein kinase (MAPK) signaling pathways, preventing the lipopolysaccharide (LPS)-mediated disruption of the intestinal epithelial cell barrier.

Aromatic-turmerone ameliorates DSS-induced ulcerative colitis via modulating gut microbiota in mice

Curcuma longa L. is one of the traditional Chinese herbs in the list of medicinal and food homology. Aromatic-turmerone is the main ingredient in turmeric essential oil. The aim of the present study is to investigate the treatment of Aromatic-turmerone on DSS-included colitis and its regulatory effect on intestinal flora disorder. Male KM mice supplemented with different concentration of aromatic-turmerone and mesalazine are subjected to 2% DSS in drinking water to induce colitis. Colon and cecum contents were collected for colitis lesion evaluation and inflammation-related gene analysis and colon contents for gut microbiota. The results show that treatments with Aromatic-turmerone significantly prevents colon shortening, alleviates the damage of colonic tissue, and reduces colonic inflammatory cytokines TNF-α and COX-2. Furthermore, the 16S rDNA gene sequence data indicate that Aromatic-turmerone improve the abundance of bacterial species, maintain some beneficial bacteria, and reduce harmful bacteria. Aromatic-turmerone downregulates the colonic inflammatory cytokines and modulates the abundance of intestinal flora, which is conductive to ameliorates DSS-induced colitis. Regularly intake of the edible herb may be help to prevent ulcerative colitis-related diseases.

Oral administration of octacosanol modulates the gut bacteria and protects the intestinal barrier in ulcerative colitis mice

Octacosanol (Oct), a kind of long-chain fatty alcohol extracted from rice bran was applied to study its effects on alleviating ulcerative colitis (UC). Oct was orally administered at 10 mg/kg (Oct-L) and 30 mg/kg (Oct-H) to dextran sulfate sodium (DSS)-induced mice. Here, we reported that oral administration of 30 mg/kg Oct can significantly prevent the weight loss, colon shortening, and decrease the disease activity index (DAI) score. Oct-H supplementation modified the intestinal flora by lowering the Firmicutes/Bacteroidetes (F/B) ratio, increasing the abundance of Prevotellaceae, S24-7, Turicibacter, and meanwhile decreasing Enterococcus and Stenotrophomonas. Based on the PICRUSt2 analysis, Oct-H may exert effects by anti-inflammation and xenobiotics degradation. Furthermore, short-chain fatty acids (SCFAs) levels were raised and the integrity of the gut barrier was protected. In conclusion, Oct-H can relieve clinical symptoms, modulate the gut bacteria and protect the intestinal barrier in UC mice, suggesting the potential of Oct as a food supplementation in alleviating UC. PRACTICAL APPLICATIONS: Ulcerative colitis (UC) is a hard-to-cure disease, with increasing morbidity in recent years. Therefore, finding out a food supplement to alleviate UC is very meaningful. In this work, we showed that octacosanol significantly alleviated ulcerative colitis in mice. We revealed, for the first time, octacosanol's effects on protecting the integrity of the gut barrier, modulating the intestinal flora and its metabolism (SCFAs). Therefore, octacosanol was expected to prevent colitis in an all-round way. Our research might also lay the theoretical foundation for the further development of related functional foods.

Prevention of Ulcerative Colitis in Mice by Sweet Tea (Lithocarpus litseifolius) via the Regulation of Gut Microbiota and Butyric-Acid-Mediated Anti-Inflammatory Signaling

Sweet tea (Lithocarpus litseifolius [Hance] Chun) is a new resource for food raw materials, with plenty of health functions. This study aimed to investigate the preventive effect and potential mechanism of sweet tea extract (STE) against ulcerative colitis (UC). Briefly, BABL/c mice were treated with STE (100 and 400 mg/kg) for 2 weeks to prevent 3% dextran sulfate sodium (DSS)-induced UC. It was found that STE supplementation significantly prevented DSS-induced UC symptoms; suppressed the levels of pro-inflammatory mediators, such as myeloperoxidase and tumor necrosis factor-α; increased the levels of anti-inflammatory cytokines; and up-regulated the expression of tight junction proteins (Zonula occludens-1 and Occludin). STE also altered the gut microbiota profile of UC mice by increasing Bacteroidetes, Lactobacillus, Akkermansia, Lachnospiraceae_NK4A136_group, and Alistipes and inhibiting Firmicutes, Proteobacteria, and Helicobacter, accompanied by a significant increase in the content of butyric acid. Moreover, STE increased the expression of G-protein-coupled receptor (GPR) 43 and GPR109A and inhibited the expression of histone deacetylase 3 (HDAC3) and nuclear factor-κB p65 (NF-κB p65) in the colon. In conclusion, this study indicated that STE has a good preventive effect on UC by regulating gut microbiota to activate butyrate-GPR-mediated anti-inflammatory signaling and simultaneously inhibit HDAC3/NF-κB inflammatory signaling.

Ethanolic extract from Lepidium virginicum L. ameliorates DNBS-induced colitis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Lepidium virginicum L. (Brassicaceae) is a plant widely used in traditional Mexican medicine as an expectorant, diuretic, and as a remedy to treat diarrhea and dysentery, infection-derived gastroenteritis. However, there is no scientific study that validates its clinical use as an anti-inflammatory in the intestine.

AIM OF THE STUDY

This study aimed to investigate the anti-inflammatory properties of the ethanolic extract of Lepidium virginicum L. (ELv) in an animal model of inflammatory bowel disease (IBD)-like colitis.

MATERIALS AND METHODS

The 2,4-dinitrobenzene sulfonic acid (DNBS) animal model of IBD was used. Colitis was induced by intrarectal instillation of 200 mg/kg of DNBS dissolved vehicle, 50% ethanol. Control rats only received the vehicle. Six hours posterior to DNBS administration, ELv (3, 30, or 100 mg/kg) was administered daily by gavage or intraperitoneal injection. The onset and course of the inflammatory response were monitored by assessing weight loss, stool consistency, and fecal blood. Colonic damage was evaluated by colon weight/length ratio, histopathology, colonic myeloperoxidase (MPO) activity, and gene expression of proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), chemokine C-X-C motif ligand 1 (CXCL-1), and interleukin-6 (IL-6).

RESULTS

Rats treated with DNBS displayed significant weight loss, diarrhea, fecal blood, colon shortening, a significant increase in immune cell infiltration and MPO activity, as well as increased proinflammatory cytokine expression. Intraperitoneal administration of ELv significantly reduced colon inflammation, whereas oral treatment proved to be ineffective. In fact, intraperitoneal ELv significantly attenuated the clinical manifestations of colitis, immune cell infiltration, MPO activity, and pro-inflammatory (CXCL-1, TNF-α, and IL-1β) gene expression in a dose-dependent manner.

CONCLUSION

Traditional medicine has employed ELv as a remedy for common infection-derived gastrointestinal symptoms; however, we hereby present the first published study validating its anti-inflammatory properties in the mitigation of DNBS-induced colitis.

Atractylenolide III Improves Mitochondrial Function and Protects Against Ulcerative Colitis by Activating AMPK/SIRT1/PGC-1α

Ulcerative colitis (UC) is a complex inflammatory bowel disease (IBD) associated with mitochondrial function. Atractylenolide III (AT III) is a natural product with anti-inflammatory effects. The aim of this work is to investigate the protective effect of AT III on UC and its underlying mechanisms. Herein, dextran sulfate sodium- (DSS-) induced mice and lipopolysaccharide- (LPS-) stimulated intestinal epithelial cells (IEC-6) were employed to mimic UC pathologies in vivo and in vitro. The results showed that in DSS-induced mice, AT III significantly reversed the body weight loss, colon length reduction, disease activity index (DAI) increase, and histological damage. The production of proinflammatory factors and reduction of antioxidants in colitis were suppressed by AT III. In addition, we demonstrated that AT III attenuated the intestinal epithelial barrier destruction and mitochondrial dysfunction induced by DSS, which was similar to the in vitro results in LPS-treated IEC-6 cells. The protein levels of p-AMPK, SIRT1, and PGC-1α along with acetylated PGC-1α were also upregulated by AT III in vivo and in vitro. In conclusion, these findings support that AT III may protect against mitochondrial dysfunction by the activation of the AMPK/SIRT1/PGC-1α signaling pathway during UC development.

Effects of the Traditional Chinese Medicine Formula Ento-PB in Experimental Models of Ulcerative Colitis

The traditional Chinese medicine (TCM) formula Ento-PB containing Periplaneta americana (Linnaeus) (Blattidae) and Taraxacum mongolicum Hand.-Mazz. (Compositae) has great potential for treating inflammation. This study explored the effects of Ento-PB on ulcerative colitis (UC). The UC model was induced with 2,4,6-trinitrobenzene sulfonic acid (TNBS) by enema. Male Sprague–Dawley rats (n = 32) were divided into four groups: (1) control group that received 2.5 mL/kg normal saline, (2) TNBS group that received 2.5 mL/kg normal saline, (3) Ento-PB low-dose group that received 100 mg/kg Ento-PB, and (4) Ento-PB high-dose group that received 200 mg/kg Ento-PB. Rats were administered drugs via enema for 14 days after modeling. The disease activity index (DAI), colon mucosa damage index (CMDI), histopathological score (HS), levels of interleukin-8 (IL-8), IL-10, IL-17, tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) in serum, contents of IL-2, myeloperoxidase (MPO), transforming growth factor-β1 (TGF-β1), and epidermal growth factor (EGF) in the colon, and abundance of Bifidobacterium, Lactobacillus, Enterococcus, Bacteroides, and Escherichia coli were assessed. Ento-PB administration showed a significant reduction in DAI, CMDI, and HS, contents of IL-2, IL-8, IL-17, TNF-α, CRP, and MPO, and a significant increase in the levels of IL-10, TGF-β1, and EGF. Compared with the TNBS-administered group, the abundance of Bifidobacterium, Lactobacillus, Enterococcus, and E. coli decreased, while an obvious increase in the proportion of Bacteroides was found in the Ento-PB-administered groups. Ento-PB alleviated inflammation in UC by regulating the equilibrium of Th1/Th17/Treg cytokines and recovering the imbalance between the gut microbiota. Applying Ento-PB in treating UC could be suggested.

Efficacy and Safety of Probiotics Combined With Traditional Chinese Medicine for Ulcerative Colitis: A Systematic Review and Meta-Analysis

Background: The combination of probiotics and traditional Chinese medicine (TCM) is a prospective therapy for ulcerative colitis (UC), and its efficacy and safety need to be urgently evaluated.

Objective: This study aims to comprehensively assess the efficacy and safety of probiotics combined with TCM for the treatment of UC.

Methods: The Pubmed, EMBASE, Cochrane library, China Academic Journals (CNKI), Wan-fang database, Chinese biomedical literature service system (CBM), and Chinese Science and Technology Journals (CQVIP) were searched. Subgroup analysis were designed in accordance with different control drugs, treatment courses, and types of probiotics. The Review Manager software (version 5.4.1) was utilized for statistical analysis.

Results: 14 original studies containing 1,154 patients were analyzed and showed that probiotics with TCM was more effective than 5-aminosalicylic acid (5-ASA), probiotics or TCM used individually. Moreover, probiotics combined with TCM could inhibit the intestinal inflammation, reduce the recurrence rate and the incidence of adverse events. The subgroup analysis showed that a mixture of different probiotics was more effective than a single strain.

Conclusion: It is suggested that probiotics combined with TCM could effectively control clinical symptoms, inhibit intestinal inflammatory response, and finally slow down the disease progress and reduce the disease recurrence with less adverse events. The mixture of different probiotics used in conjunction with individually tailored TCM is a potential clinical strategy for UC.

Substantial Intestinal Microbiota Differences Between Patients With Ulcerative Colitis From Ghana and Denmark

Background

Ulcerative colitis (UC) is a relapsing nontransmural inflammatory disease that is restricted to the colon and is characterized by flare-ups of bloody diarrhea. In this study, we aimed to investigate intestinal bacterial diversity in healthy controls and patients with UC with and without active disease, from Ghana and Denmark.

Methods

The study included 18 UC patients (9 with active and 9 with inactive disease) and 18 healthy controls from Ghana. In addition 16 UC patients from Denmark (8 UC with active and 8 UC with inactive disease) and 19 healthy controls from Denmark. Microbiota diversity analysis relied on sequencing of ribosomal small subunit genes. Purified genomic DNA was submitted to PCR using a primer set targeting prokaryotes and eukaryotes. The purified DNA was sequenced on the Illumina MiSeq system in a 2 × 250 bp set up (Illumina, San Diego, CA, USA). Blinded analysis of the taxonomy table was performed using BioNumerics-7.5 (Applied Maths NV, Sint-Martens-Latem, Belgium).

Results

When analyzing the taxonomy data for prokaryotes, cluster and principal component analysis shows Danish healthy controls clustered together, but separate from healthy controls from Ghana, which also clustered together. The Shannon diversity index (SDI) for prokaryotes shows significant differences between Danish healthy controls and patients in comparison with the corresponding groups from Ghana (p = 0.0056). Significant increased abundance of Escherichia coli was detected in healthy controls from Ghana in comparison with healthy controls from Denmark. The SDI of the prokaryotes ranges between 0 and 3.1 in the Ghana study groups, while in the Danish study groups it ranges between 1.4 and 3.2, the difference is however not significant (p = 0.138). Our data show a significant increased abundance of eukaryotes species in the healthy control group from Ghana and Denmark in comparison with patient groups from Ghana and Denmark.

Conclusion

Overall, healthy controls and patients with UC from Denmark have increased diversity of prokaryotes. Healthy controls from Denmark and Ghana have increased abundance of eukaryotes in comparison with UC patient groups from Denmark and Ghana.

Yiyi Fuzi Baijiang Decoction Alleviates Ulcerative Colitis Partly by Regulating TLR4-Mediated PI3K/Akt and NF-κB Pathways

Yiyi Fuzi Baijiang Decoction (YFBD), an ancient prescription developed by the ancient Chinese physician, Zhang Zhongjing, has shown remarkable effects in treating ulcerative colitis (UC). However, there are few studies on its mechanism. This study was designed to explore the potential mechanism of YFBD in treating UC. The principal ingredients of YFBD were analyzed using high-performance liquid chromatography (HPLC). Dextran sulfate sodium- (DSS-) induced mice and lipopolysaccharide- (LPS-) stimulated RAW264.7 cells were used in the study. The body weight and disease activity index (DAI) of mice were recorded and analyzed for 10 days. After sacrifice, the colonic tissues were harvested. The colon length was measured, and the histopathological changes were observed by hematoxylin and eosin staining. The levels of inflammatory cytokines in mice colons and RAW246.7 cells were determined by real-time quantitative PCR and immunofluorescence. The effects of YFBD on the TLR4-mediated PI3K/Akt and NF-κB pathways were determined by western blot analysis. HPLC identified five compounds in YFBD: chlorogenic acid, caffeic acid, benzoylmesaconine, benzoyl aconitine, and quercetin. YFBD alleviated weight loss, colon shortening, and colonic histopathological lesion in mice. Meanwhile, it decreased the DAI and histological score of mice with UC. In addition, YFBD remarkably decreased the levels of interleukin- (IL-) 6, IL-1β, and tumor necrosis factor (TNF)-α in the colons of DSS-induced mice and LPS-stimulated RAW246.7 cells. Furthermore, the expression of key proteins in TLR4-mediated PI3K/Akt and NF-κB pathways significantly decreased with YFBD treatment. In conclusion, YFBD had protective effects on mice with UC, which was in part related to its anti-inflammatory effects and downregulation of TLR4-mediated PI3K/Akt and NF-κB pathways.

Pectic polysaccharide from Smilax china L. ameliorated ulcerative colitis by inhibiting the galectin-3/NLRP3 inflammasome pathway

Ulcerative colitis (UC) is an inflammatory bowel disease that affects the colon and rectum. Although galectin-3 (Gal-3) has been reported to play a proinflammatory role in UC, it is unknown whether pectic polysaccharide, a Gal-3 inhibitor in tumor metastasis, can alleviate UC by inhibiting Gal-3. The aim of this study was to investigate the anti-inflammatory effects and underlying mechanisms of SCLP, a pectic polysaccharide purified from Smilax china L. in our previous work, on dextran sulfate sodium-induced UC in BALB/c mice. The results showed that SCLP could significantly improve symptoms, alleviate histopathological damage and reduce the secretion of inflammatory mediators in mice with UC. Analysis of the anti-colitis mechanisms indicated that SCLP could inhibit the Gal-3/NLRP3 inflammasome/IL-1β pathway by suppressing the expression of Gal-3 and the interaction of Gal-3 and NLRP3. Our results suggested that SCLP could be a promising candidate for prevention and treatment of UC.