Dextran Sulfate Research Articles

Iron and Inflammatory Cytokines Synergistically Induce Colonic Epithelial Cell Ferroptosis in Colitis.

Inflammatory bowel disease (IBD) is an inflammatory disease that occurs to the intestinal tract. Many patients with IBD often develop anemia and often receive oral iron supplementation. Many of them develop non-compliance with oral iron therapy, but the mechanisms are not well understood. We interrogated whether colonic epithelial iron overload impacts cell viability and disease severity. We observed increased expression of iron importers and iron accumulation in mature colonocytes in dextran sulfate sodium (DSS)-induced acute colitis and in humans with active colitis. Administration of hepcidin increased epithelial iron overload and aggravated colonic inflammation in DSS-treated mice and IL10-/- mice. Hepcidin-induced iron accumulation increased colonic epithelial death, which was prevented by treatment with Trolox, a vitamin E analog and a scavenger of lipid peroxides. By using cultured Caco-2 cells, we showed that iron and inflammatory cytokines (TNF-α and IL-1β) induced a synergistic increase in the number of necrotic cells. We then showed that the combined treatment by hepcidin and cytokines increased labile iron content and lipid peroxidation in Caco-2 cells. Moreover, liproxstatin-1, a ferroptosis inhibitor, and deferoxamine, an iron chelator, both abolished the hepcidin/cytokines induced death of Caco-2 cells, suggesting ferroptosis. We further elucidated that inflammatory cytokines promote lipid peroxidation and ferroptosis by inducing NOX1-dependent exhaustion of reduced glutathione (GSH). Collectively, our findings demonstrate that the inflammatory context predisposes colonic epithelial cells to iron overload mediated ferroptosis, exacerbating colonic inflammation.

Taraxasterol Acetate From Taraxacum officinale Ameliorates Dextran Sulfate Sodium–Induced Ulcerative Colitis in Mice in Association With Changes of the Metabolism and Structure of Gut Microbiota

ABSTRACTUlcerative colitis (UC) is closely associated with the structural and metabolic disorders of gut microbiota. Taraxasterol acetate (TSA) from Taraxacum officinale (TO) has anti‐inflammatory activity. In this study, to investigate the therapeutic potential of TSA and its mechanism of action in dextran sulfate sodium (DSS)‐induced UC. The anti‐inflammatory effects of TSA were evaluated in vitro. DSS‐induced UC animal models and TSA gavage were employed for in vivo experiments. The results indicated that TSA showed good anti‐inflammatory effects both in vitro and in vivo, and the anti‐UC effect of TSA was better than that of the extract in vivo. TSA relieved clinical symptoms in DSS‐induced UC mice and repaired the intestinal barrier. TSA restored the structural disorder of gut microbiota and regulated metabolic levels in DSS‐induced UC mice. This study provides a fresh perspective on developing new therapeutic methods against UC using the traditional Chinese medicine TSA.

Therapeutic potential of Lacticaseibacillus rhamnosus grx10 and its derived postbiotic through gut microbiota and MAPK/MLCK/MLC pathway-mediated intestinal barrier repairment in ulcerative colitis.

Lacticaseibacillus rhamnosus grx10 (grx10) has shown promising potential in promoting intestinal health as predicted by genomic and metabolomic analyses. Given the increasing prevalence of ulcerative colitis (UC) and the limitations of existing treatments, exploring alternative therapeutic strategies is essential. This study explored the therapeutic effects and underlying mechanisms of grx10 and its derived postbiotic (P-grx10) in a mouse model of dextran sulfate sodium (DSS)-induced chronic UC. The intervention with grx10 and P-grx10 significantly alleviated clinical symptoms and improved biochemical markers in UC mice. These effects included reducing the disease activity index (DAI), improving colon length and histopathological damage, decreasing the secretion of inflammatory cytokines, and preventing the reduction of antioxidant enzymes. Additionally, grx10 and P-grx10 downregulated key proteins in the Mitogen-Activated Protein Kinase (MAPK)/myosin light chain kinase (MLCK)/myosin light chain (MLC) pathway, prevented the dissociation of tight junction (TJ) proteins and E-cadherin, reduced intestinal permeability, and restored the integrity of the intestinal barrier. Furthermore, both grx10 and P-grx10 modulated the composition and abundance of gut microbiota, helping to maintain intestinal microbiome homeostasis. In conclusion, this study provided evidence regarding the role of grx10 and P-grx10 in alleviating intestinal barrier dysfunction associated with UC and restoring gut microbiota balance. Notably, P-grx10 exhibited higher anti-inflammatory activity and better restoration of intestinal barrier function, whereas the live probiotic grx10 showed a stronger regulatory effect on the gut microbiota. These findings suggest that grx10 and P-grx10 could serve as promising nutritional adjunct therapies for UC, providing novel insights into the distinct roles of probiotic and its derived postbiotic in UC treatment.

The protective effect of amitriptyline on experimental colitis through inhibiting TLR-4/MD-2 signaling pathway

Amitriptyline, a pleiotropic tricyclic antidepressant, possesses antioxidant and anti-inflammatory properties. Despite its diverse benefits, the specific effects of amitriptyline on inflammatory bowel disease (IBD) are not yet well defined. To explore this, we used a dextran sulfate sodium (DSS)–induced colitis model to examine the anti-inflammatory effects of amitriptyline and the underlying mechanisms by which it operates. Our research revealed that amitriptyline is effective in alleviating several pathological manifestations associated with colitis. This includes improving body weight retention, reducing disease activity index, lessening of colon length shortening, and repairing of colonic mucosal damage. Treatment with amitriptyline significantly protected mucosal injury by preserving the population of goblet cells and increasing the expression of tight junction proteins. Furthermore, we observed that amitriptyline effectively countered immune cell infiltration, specifically neutrophils and macrophages, while simultaneously lowering the levels of inflammatory cytokines such as tumor necrosis factor α, interleukin (IL)-1β, and IL-6. Additionally, RNA sequencing analysis pointed to the potential involvement of the Toll-like receptor (TLR) pathway in the anticolitic effects induced by amitriptyline. Subsequent Western blot analysis indicated that amitriptyline significantly inhibited the TLR-4–mediated nuclear factor (NF)-κB signaling pathway. To bolster our findings, in vitro studies demonstrated that amitriptyline downregulated the TLR-4/NF-κB/mitogen-activated protein kinase signaling cascades in mouse macrophages stimulated with lipopolysaccharide. Further molecular investigations revealed that amitriptyline was able to suppress the elevated expression of myeloid differentiation factor 2 that lipopolysaccharide stimulation typically induces. In summary, our findings suggest that amitriptyline effectively mitigates DSS–induced colitis in mice through the inhibition of TLR-4/myeloid differentiation 2 pathway signaling, indicating its potential repurposing for IBD treatment. Significance StatementThe potential of using amitriptyline in treating inflammatory bowel disease appears promising, leveraging its established safety and dosing profile as an antidepressant. The study results show that amitriptyline can alleviate pathological symptoms, inflammation, and intestinal mucosal damage in mice with colitis induced by DSS. The protective effect observed appears to be linked to the inhibition of TLR-4/myeloid differentiation 2 signaling pathway. By exploring novel applications for existing medications, we can optimize amitriptyline’s efficacy and broaden its impact in both medical and commercial contexts.

Abdominal ultrasound stimulation alleviates DSS-induced colitis and behavioral disorders in mice by mediating the microbiota–gut–brain axis balance

Inflammatory bowel disease (IBD) has the potential to induce neuroinflammation, which may increase the risk of developing neurodegenerative disorders. Ultrasound stimulation to the abdomen is a potential treatment for dextran sulfate sodium (DSS)-induced acute colitis. The present study aimed to investigate whether abdominal low-intensity pulsed ultrasound (LIPUS) can alleviate DSS-induced neuroinflammation through the microbiota–gut–brain axis. Male mice were fed DSS to induce ulcerative colitis. LIPUS stimulation was then applied to the abdomen at intensities of 0.5 and 1.0 ​W/cm2. Mouse biological samples were analyzed, and behavior was evaluated. [18F]FEPPA PET/CT imaging was employed to track and quantify inflammation in the abdomen and brain. Changes in the gut microbiota composition were analyzed using 16S rRNA sequencing. Abdominal LIPUS significantly inhibited the DSS-induced inflammatory response, repaired destroyed crypts, and partially preserved the epithelial barrier. [18F]FEPPA accumulation in the colitis-induced neuroinflammation in the abdomen and specific brain regions significantly decreased after LIPUS treatment. LIPUS maintained intestinal integrity by increasing zonula occludens and occludin levels, reduced lipopolysaccharide-binding protein and lipopolysaccharide levels in the serum, and improved behavioral dysfunctions. Moreover, LIPUS, at an intensity of 0.5 ​W/cm2, reshaped the gut microbiota in colitis-induced mice by increasing the relative abundance of the Firmicutes and decreasing the relative abundance of the Bacteroidota. Our findings demonstrated that abdominal LIPUS stimulation has the potential to be a novel therapeutic strategy to improve colitis-induced behavioral disorders through microbiota–gut–brain axis signaling.

Citrus rhoifolin alleviated DSS-induced acute colitis by activating CEMIP/SLC7A11-mediated cystine uptake and inhibiting epithelial ferroptosis.

Pharmacological inhibition of ferroptosis, a specific form of regulated cell death, has emerged as a promising therapeutic strategy for alleviating symptoms and enhancing endoscopic outcomes in patients suffering from ulcerative colitis. Rhoifolin, a prominent bioactive constituent abundant in the widely consumed fruit Citrus grandis (grapefruit), has garnered attention for its ability to diminish the levels of reactive oxygen species (ROS), which are key inducers of ferroptosis across diverse cellular contexts. In this study, we aimed to investigate whether rhoifolin exerts its beneficial effects on colitis by modulating the process of epithelial ferroptosis. Colitis model was successfully established in C57BL/6 mice through the administration of 2.5% dextran sulfate sodium (DSS) solution for a duration of 9days, which was freely accessible for drinking. RNA sequencing was conducted to delve into the mechanisms underlying the rhoifolin-mediated effects on colitis. To evaluate the impact of rhoifolin on ferroptosis in epithelial cells, several key indicators were measured, including mitochondrial morphology, colonic glutathione (GSH) levels, lipid peroxidation product contents, and ROS levels. The results indicated that rhoifolin exhibited profound anti-colitis properties and effectively curbs ferroptosis in epithelial cells of mice subjected to DSS treatment. The RNA sequencing analysis further revealed that rhoifolin stimulated a remarkable upregulation of colonic cell migration-inducing protein (CEMIP) expression by approximately 2.4-fold in colitis-affected mice. Notably, depletion of CEMIP significantly blocked the rhoifolin-induced increase in the cystine transporter solute carrier family 7 member 11 (SLC7A11, from 1.9-fold to approximately 1.1-fold), as well as the elevation of cystine uptake (from 1.72-fold to 1.2-fold) and glutathione (GSH) biosynthesis (from 2.1-fold to 1.2-fold), and the suppression of epithelial ferroptosis (from 0.51-fold to 0.94-fold) in mice with colitis. Molecular docking investigations have pinpointed crucial amino acid residues within CEMIP, specifically His267, His289, and Phe265, as the primary interaction sites (docking score: -7.8kcal/mol), facilitating the engagement of rhoifolin via hydrogen bonding interactions. Rhoifolin significantly mitigated DSS-induced colitis primarily through inhibiting epithelial ferroptosis. The activation of CEMIP by citrus-derived rhoifolin led to a notable upregulation of SLC7A11 expression, thereby enhanced cystine uptake and facilitated GSH biosynthesis, ultimately suppressed the occurrence of ferroptosis in epithelial cells.

Heat-killed Lacticaseibacillus paracasei 6235 is more effective than live on DSS-induced colitis via modulation of intestinal microbiota and MAPK/NF-κB signaling pathways.

This study compared the protective effects of both live Lacticaseibacillus paracasei 6235 (LLP 6235) and heat-killed Lacticaseibacillus paracasei 6235 (HK-LP 6235) on ulcerative colitis. Using a dextran sulfate sodium (DSS)-induced colitis mouse model, we evaluated physiological state, colon tissue integrity, inflammatory factors, tight junction (TJ) proteins, and intestinal microbiota variations. The findings demonstrated that both LLP 6235 and HK-LP 6235 have the capacity to mitigate colitis damage, enhance TJ protein levels, and restore colon morphology. In addition, these interventions modulated the intestinal inflammatory response by inhibiting pro-inflammatory factors and upregulating anti-inflammatory factors through the mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways. Moreover, treatment with LLP 6235 and HK-LP 6235 significantly altered intestinal microbiota diversity, increased the relative abundance of beneficial bacteria, and regulated the short-chain fatty acid (SCFA) levels. Spearman correlation analysis revealed a strong association between TJ proteins, SCFAs, intestinal microbiota, and inflammatory response, suggesting that LLP 6235 and HK-LP 6235 may provide an effective approach to colitis prevention. In conclusion, LLP 6235 and HK-LP 6235 have similar abilities; furthermore, HK-LP 6235 modulated the intestinal microbiota through lipid metabolic pathways, resulting in a greater improvement. Moreover, considering the high stability and safety of prebiotics and their wide applicability, HK-LP 6235 is recommended for use as a modulator of intestinal inflammatory diseases.

Phenolics-Rich Extract from Agarwood Leaf-Tea Alleviate Dextran Sulfate Sodium (DSS)-Induced Ulcerative Colitis Via Modulating Intestinal Barrier Function, Liver Inflammation, and Gut Microbiota.

At present, the incidence rate of ulcerative colitis (UC) continues to increase, causing a global burden. In addition, therapeutic drugs have great side effects. According to modern pharmacology, agarwood leaves have anti-inflammatory, antibacterial, hypoglycemic, and lipid-lowering effects. Therefore, this experiment on DSS induced colitis treatment of polyphenolic substances in agarwood leaves is feasible and in line with the current hot topic of using natural substances instead of drugs for treatment. ALP supplementation promotes the expression of tight junction proteins occludin and Zonula occludens protein 1 (ZO-1) on colonic tissues, repairs the intestinal barrier, and relieves further colonic tissue damage. Besides, ALP effectively inhibits the activation of nuclear factor kappa-B (NF-кB) signaling pathway and reduces the release of proinflammatory cytokines. Moreover, ALP reverses the alteration of gut microbiota in the colitic mice by increasing the abundances of Parabacteroides, Chlamydia, and Lachnospiraceae, and decreasing the abundances of Bacteroides and Phocaeicola. Furthermore, the correlation analysis suggested that ALP can attenuate DSS-induced UC, which is probably related to the alterations in the gut microbiota. ALP can ameliorate DSS-induced UC by modulating gut microbiota, intestinal barrier function, and inflammatory responses.

The resolvin D2 and omega-3 polyunsaturated fatty acid as a new possible therapeutic approach for inflammatory bowel diseases

Inflammatory bowel diseases (IBD) are idiopathic disorders characterized by chronic gastrointestinal inflammation. Given conventional therapies’ adverse effects and clinical failures, novel approaches are being investigated. Recent studies have highlighted the role of specialized pro-resolving lipid mediators (SPMs) in the active resolution of chronic inflammation. In this regard, omega-3 fatty acid-derived Resolvin D2 (RvD2) appears to play a protective role in the pathophysiology of IBD. Therefore, we characterized the RvD2 pathway and its receptor expression in the intestinal mucosa of experimental colitis induced by dextran sulfate sodium. We also evaluated the preventive impact of an omega-3-enriched diet and the therapeutic efficacy of RvD2 compared with anti-TNF-α treatment. We found an increase in TNFα and IL22 expression and decreased levels of enzymes involved in RvD2 biosynthesis, such as PLA2, 15-LOX, 5-LOX, and its receptor GPR18 in experimental colitis. Omega-3 supplementation reduced the Disease Activity Index (DAI), weight loss, colonic shortening, and inflammation. These results and the increased IL-10 transcriptional levels after RvD2 treatment suggest that this mediator attenuated experimental colitis. These results enhance our understanding of the molecular mechanisms involved in the exacerbated inflammatory response present in experimental colitis and suggest that RvD2 and its omega-3 precursor offer a promising therapeutic approach for IBD.

Akkermansia muciniphila ONE effectively ameliorates dextran sulfate sodium (DSS)-induced ulcerative colitis in mice.

Akermansia muciniphila shows promise as a next-generation probiotic, however, its beneficial regulatory effects on mice ulcerative colitis (UC) has not been extensively investigated. We used an Akkermansia muciniphila strain (AKK ONE) isolated from healthy human feces to study its effect on DSS-induced colitis in mice. Our results demonstrate that AKK ONE supplementation significantly improves food intake, weight, colon length, disease activity index (DAI) score, organ index, and tissue damage of colitis mice. AKK ONE notably improved intestinal barrier integrity by significantly enhancing expression of occludin and claudin-1. Additionally, AKK ONE reduced inflammation by down-regulating IL-1β, IL-6, and TNF-α, and up-regulating IL-10. In addition to reducing excessive inflammation, AKK ONE also increased the abundance of Akkermansia and decreased the abundance of Bacteroides. Furthermore, the AKK ONE intervention markedly increased SCFAs in cecal contents. AKK ONE may be a potential therapeutic agent for improving UC, based on the findings of this study.

HMGB1 Modulates Macrophage Metabolism and Polarization in Ulcerative Colitis by Inhibiting Cpt1a Expression.

Macrophage polarization is involved in the development of ulcerative colitis (UC). This study investigated the mechanism by which high mobility group box-1 protein (HMGB1) regulates macrophage polarization through metabolic reprogramming, thereby contributing to the pathogenesis of UC. Dextran sulfate sodium (DSS) was used to induce colitis in mice. RAW264.7 cells were polarized to M1 or M2 macrophages in vitro by stimulating with lipopolysaccharide (LPS)/interferon-γ (IFN-γ) or Interleukin-4 (IL-4), respectively. Macrophage infiltration and distribution within colon tissue were assessed by immunohistochemistry and flow cytometry. Glycolysis, fatty acid oxidation (FAO), and inflammatory factors were evaluated using relevant reagent kits. Chromatin Immunoprecipitation (ChIP) and luciferase reporter experiments were performed to study the regulation of Carnitine palmitoyltransferase 1A (Cpt1a) promoter transcriptional activity by HMGB1. The mouse UC model showed upregulated HMGB1 and increased macrophage infiltration. Overexpression of HMGB1 promoted M1 macrophage polarization, increased glycolysis, and reduced FAO, whereas knockdown of HMGB1 promoted M2 macrophage polarization, reduced glycolysis, and increased FAO. HMGB1 negatively regulated Cpt1a expression by inhibiting transcription of the Cpt1a promoter. Knockdown of Cpt1a reversed the effects of small interfering RNA targeting HMGB1 (si-HMGB1) on macrophage metabolism and polarization. Administration of adeno-associated virus (AAV)-shHMGB1 in vivo caused a reduction in UC symptoms and inflammation. HMGB1 modulates macrophage metabolism in UC by inhibiting Cpt1a expression, leading to increased M1 polarization. This provides a theoretical basis for the clinical application of HMGB1 inhibitors in the treatment of UC.

Sanguinarine chloride hydrate mitigates colitis symptoms in mice through the regulation of the intestinal microbiome and metabolism of short-chain fatty acids

Sanguinarine constitutes the main components of Macleaya cordata, and exhibits diverse biological and pharmacological activities. This study investigated the effects of sanguinarine chloride hydrate (SGCH) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mice. Five groups were designed to investigate the effects of SGCH on the pathological symptoms, the mRNA expression levels of inflammatory cytokines, colonic mucosal barrier damage, microbiota composition, and SCFAs metabolism in UC mice. The administration of SGCH in DSS-induced UC mice resulted in the amelioration of pathological symptoms, as evidenced by an increase in body weight, a decrease in disease activity index score, elongation of colon length, reduction in spleen index, and improvement in colon injury. SGCH can regulate the expression of inflammatory cytokines (IL-6, TNF-α, IL-1β and IL-10) and tight junction proteins (ZO-1 and Occludin) associated with UC. SGCH exhibited a significant decrease in NF-κB P65 mRNA expression levels, accompanied by a significantly reduced protein level of NF-κB P-P65/P65. Further studies revealed SGCH effectively reversed the decrease in intestinal microbiota diversity induced by UC, thereby promoting the growth of beneficial bacteria such as Akkermansia, Alistipes, and norank_o_Clostridia_UCG-014. Correlation analysis demonstrated a positive association between butanoic acid, propanoic acid, isobutyric acid, isovaleric acid, valeric acid, hexanoic acid with Colidextribacter, while Coriobacteriaceae_UCG-002 exhibited a negative correlation with butanoic acid, acetic acid and propanoic acid. In conclusion, the administration of SGCH can ameliorate clinical symptoms in UC mice, regulate the expression of inflammatory cytokines and tight junction proteins, modulate intestinal microbiota metabolism and SCFAs production.

Anti-Inflammatory Effects of Novel Probiotic Lactobacillus rhamnosus RL-H3-005 and Pedicoccus acidilactici RP-H3-006: In Vivo and In Vitro Evidence.

Probiotics have garnered escalating attention in the treatment and prevention of inflammatory disorders. In this study, Lactobacillus rhamnosus RL-H3-005 (RL5) and Pediococcus acidilactici RP-H3-006 (RP6), which possess anti-inflammatory effects and favorable probiotic attributes, were selected through the comparison of an RAW264.7 inflammatory cell model screening and in vitro probiotic properties. Subsequently, it was implemented in an animal model of dextran sulfate sodium (DSS)-induced colitis. The results demonstrated that RL5 and RP6 could inhibit the release of proinflammatory factors in RAW264.7 inflammatory cells and exhibited excellent environmental adaptability, adhesion, safety, and antibacterial activity. Additionally, RL5 and RP6 provided protective effects on the intestines of mice with acute colitis by reducing the levels of intestinal inflammation and oxidative stress. Concurrently, supplementation with RL5 and RP6 modulated the composition of the gut microbiota in mice. These discoveries suggest that RL5 and RP6 can be used as a novel probiotic for alleviating intestinal inflammation.

Syringin ameliorates dextran sulphate colitis via alteration oxidative stress, inflammation NF-κB signalling pathway and gut microbiota.

The objective of the current study was to investigate the potential effects of syringin against dextran sulphate colitis (DSS)-induced ulcerative colitis (UC) in mice. In vitro study was performed on the RAW 264.7 cells and cytokines and inflammatory level were estimated. The oxidative stress, inflammatory cytokines, apoptosis and inflammatory parameters were estimated. The mRNA expression and faecal samples were estimated in the colon tissue. Syringin treatment enhanced the body weight, colon length and reduced the disease activity index (DAI), spleen index. Syringin treatment remarkably suppressed the level of nitric oxide (NO), myeloperoxidase (MPO), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) along with alteration of antioxidant parameters. Syringin treatment also altered level of cytokines in the serum and colon tissue; inflammatory parameters viz., platelet-activating factor (PAF), cyclooxygenase-2 (COX-2), prostaglandin (PGE2), inducible nitric oxide synthetase (iNOS), nuclear factor κ-B (NF-κB); matrix metalloproteinases (MMP) level. Syringin significantly (p < 0.001) enhanced the level of nuclear factor erythroid 2-related factor (Nrf2) and heme oxygenase-1 (HO-1). Syringin remarkably altered the relative abundance of gut microbiota like Firmicutes, Bacteroidetes, F/B ratio, Verrucomicrobia and Actinobacteria. Syringin exhibited the protective effect against DSS-induced UC in mice via alteration of NF-κB signalling pathway.

Protective effect of a newly probiotic Lactobacillus reuteri LY2-2 on DSS-induced colitis.

This study aimed to investigate the role of a newly isolated strain L.reuteri LY2-2 in colitis in mice and explored the underlying mechanisms. METHODS L. LY2-2 was orally administered to mice with dextran sulfate sodium (DSS)-induced colitis. 5-Aminosalicylic acid (5-ASA) treatment was used as the drug control. The results showed that the disease severity of colitis mice was significantly alleviated. The intestinal inflammation was restricted by synergistically reducing pro-inflammatory cytokines, inhibiting TLR4-NF-κB signaling, restoring the abnormal immune response, and enhancing intestinal barrier function. Of note, L.reuteri LY2-2 showed great potential in modulating macrophages polarization in colonic tissues. Moreover, the gut dysbiosis was improved. The potentially pro-inflammatory pathogenic bacteria such as Helicobacter and Romboutsia decreased and the probiotics including L.rhamnosus and L.plantarum increased. Interestingly, the above pathological indexes in the L.reuteri LY2-2 group were better than those in the 5-ASA group. L.reuteri LY2-2 had a better protective effect on DSS-induced colitis via its anti-inflammatory and microbiota-balancing properties, which supports the potential value of this probiotic against colitis. These results contribute to product development of functional probiotics for colitis and provide valuable insights for their mechanisms of biological function to affect human health status.

Presence of Pseudomonas aeruginosa in feces exacerbate leaky gut in mice with low dose dextran sulfate solution, impacts of specific bacteria.

The impact of Pseudomonas aeruginosa (PA) was explored in a mouse model with non-diarrheal gut permeability defect using 1.5% dextran sulfate solution (DSS) plus antibiotics (ATB) with or without orally administered PA. As such, ATB+DSS+PA mice induced more severe intestinal injury as indicated by stool consistency and leaky gut (FITC-dextran assay, bacteremia, and endotoxemia) with an increase in serum cytokines, liver enzyme, and hepatocyte apoptosis when compared with ATB+DSS mice. There was no abnormality by these parameters in the non-DSS group, including water alone (control), antibiotics alone (ATB+water), and antibiotics with PA (ATB+water+PA). Despite a similarly fecal microbiome patterns between ATB+DSS and ATB+DSS+PA groups, a higher abundance of Pseudomonas, Enterococci, and Escherichia-Shigella was detected in ATB+DSS+PA mice. Additionally, the additive pro-inflammation between pathogen molecules, using heat-killed P. aeruginosa preparations, and LPS against enterocytes (Caco2) and hepatocytes (HegG2), as indicated by supernatant IL-8 and expression of several genes (IL-8, NF-kB, and NOS2) are demonstrated. In conclusion, presence of P. aeruginosa in the gut exacerbated DSS-induced intestinal injury with spontaneous translocation of LPS and bacteria from the gut into the blood circulation (leaky gut) that induced more severe systemic inflammation. The presence of pathogenic bacteria, especially PA in stool of the healthy individuals might have some adverse effect. More studies are in needed.

Epimedium polysaccharides ameliorate ulcerative colitis by inhibiting oxidative stress and regulating autophagy.

Epimedium polysaccharide (EPS) is a bioactive compound derived from the traditional Chinese herb Epimedium brevicornum. The objective of this study was to investigate the protective effects of EPS on ulcerative colitis (UC) and to elucidate the underlying mechanisms involved. The findings showed that EPS treatment mitigated UC symptoms, including weight loss, anal bleeding, elevated disease activity index (DAI), and colon shortening. Hematoxylin and eosin (H&E) and Alcian blue-periodic acid-Schiff (AB-PAS) staining demonstrated that EPS alleviated histopathological damage and improved the integrity of the colonic mucosa. Mechanistically, EPS was found to substantially decrease inflammation by inhibiting the Toll-like receptor 4/nuclear factor-κB (TLR4/NF-κB) signaling pathway and to alleviate oxidative stress through modulation of the Kelch-like ECH-associated protein 1/nuclear factor erythroid-derived 2-like 2 (Keap1/Nrf2) pathway. Notably, EPS failed to exert protective effects against dextran sulfate sodium (DSS)-induced UC in Nrf2-knockout (Nrf2-/-) mice. Additionally, Western blotting and immunohistochemical analysis demonstrated that EPS facilitated autophagy via the adenosine monophosphate-dependent protein kinase/mammalian target of rapamycin (AMPK/mTOR) pathway. In vitro experiments revealed that EPS effectively suppressed lipopolysaccharide (LPS)-mediated cellular damage and oxidative stress by regulating Keap1/Nrf2 pathway. Transcriptomic analysis of LPS-treated Caco-2 cells following EPS treatment revealed a significant up-regulation of Nrf2 expression. In conclusion, the findings of this study suggest that EPS exerts protective effects against DSS-induced UC through the inhibition of the TLR4/NF-κB signaling pathway, regulation of the Keap1/Nrf2 pathway, and promotion of autophagy via the AMPK/mTOR pathway. Consequently, EPS may represent a potential therapeutic target for the treatment of UC. © 2024 Society of Chemical Industry.

Neohesperidin protects against colitis-associated colorectal cancer in mice via suppression of the NF-κB/p65 and MAPK pathways

Patients with inflammatory bowel disease (IBD) are at increased risk of developing colitis-associated colorectal cancer (CAC). Neohesperidin (NHP), a flavanone glycoside derived from citrus fruits, has been reported to have anti-inflammatory, antioxidant, and anticancer potential. However, the function of NHP on tumorigenesis has not been well understood. To investigate the potential chemopreventive effects of NHP on CAC development, an in vivo azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced mouse model was used and NHP was administered by daily gavage for 10 weeks throughout the model period. In this study, we found that NHP effectively ameliorated AOM/DSS-induced pathological symptoms of colitis and thus inhibited colon tumorigenesis in mice. NHP treatment attenuated tumor proliferation, induced apoptosis, and inhibited angiogenesis during CAC development. In addition, NHP inhibited macrophage infiltration and reduced the expression of proinflammatory cytokines such as TNF-α, IL-1β, IL-6, and COX-2 at both mRNA and protein levels, and the higher the concentration of NHP, the better the inhibition. It is worth noting that the positive therapeutic agent mesalazine (100 mg/kg) had a therapeutic effect comparable to that of a low concentration of NHP (50 mg/kg), but less effective than the same concentration of NHP (100 mg/kg). In addition, NHP may exert anti-inflammatory and anticancer effects by inhibiting the NF-κB/p65 and ERK/p38 MAPK pathways. Our findings highlight the potential of NHP as a potential therapeutic candidate for IBD and CAC.

MnNi@PVP Nanoenzyme Based on Regulating Inflammation and Immune Homeostasis for the Therapy of Inflammatory Bowel Disease.

Nanozymes exhibiting remarkable antioxidant capabilities represent an effective therapeutic approach for ulcerative colitis (UC). This study synthesized the MnNi@PVP nanoenzyme through high-temperature pyrolysis and the NaCl template method, which exhibited multienzyme activity comprising glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT). This study investigated the therapeutic effect of MnNi@PVP on colitis caused by sodium dextran sulfate (DSS). The findings indicated that MnNi@PVP notably decreased the disease activity index (DAI) score, which encompasses weight loss, colon shortening, and histopathological changes. MnNi@PVP showed effectiveness in addressing oxidative damage and suppressing the levels of proinflammatory markers, such as tumor necrosis factor (TNF-α), inducible nitric oxide synthase (iNOS), and interleukin (IL)-6, by inactivating the TLR4 pathway and macrophages. In addition, MnNi@PVP demonstrated the ability to repair tight junction proteins (occludin and ZO-1) and restore the intestinal barrier. The transcriptome sequencing demonstrated that MnNi@PVP could regulate inflammatory factor expression pathways and immune processes. Additionally, negatively charged MnNi@PVP can selectively bind to inflamed colonic tissues through electrostatic interactions, endowing it with targeted reparative capabilities at the location of intestinal inflammation. The MnNi@PVP, which possesses the reactive oxygen and nitrogen species (RONS) clearance capability examined in this section, is expected to provide the basis for the targeted repair of intestinal function.

Engineered vildagliptin-loaded polymeric nanoparticles via microfluidic and spray drying for enhanced antidiabetic activity

BackgroundVildagliptin (VLG), an antidiabetic agent, presents a potential solution to this widespread affliction. It exhibits notable attributes, such as a high solubility and a shorter elimination half-life. The current study uses a microreactor to fabricate sustained-release VLG-encapsulated cross-linked chitosan–dextran sulfate nanoparticles (VLG-CDNPs). The fabrication was systematically optimized using the design of experiment approach.ResultsThe optimized VLG-CDNPs had an average particle size of 217.4 ± 12.3 nm and an encapsulation efficiency of 78.25 ± 3.0%. Scanning electron microscopy revealed that the nanoparticles had a smooth spherical shape. Spray drying was used for drying, and the reconstitution ability was close to ideal (~ 1.33). In vitro studies revealed sustained VLG release over 12 h, with ~ 58% in acidic and ~ 83% in basic conditions. Cell viability remained at 80% even at 100 μg/mL, and glucose uptake in L6 cells was significantly enhanced with VLG-CDNPs (78.34%) compared to pure VLG (60.91%). VLG-CDNPs also showed moderate inhibitory activity against α-amylase (41.57%) and α-glucosidase (63.48%) compared to pure VLG, which had higher inhibition levels.ConclusionThe study’s outcome suggested that the optimized VLG-CDNPs may serve as an effective and promising nanoformulation for managing diabetes mellitus.