Dextran Sulfate Sodium Research Articles

Vitamin D3 Upregulated Protein 1 Deficiency Promotes Azoxymethane/Dextran Sulfate Sodium-Induced Colorectal Carcinogenesis in Mice.

VDUP1 acts as a tumor suppressor gene in various cancers. VDUP1 is expressed at low levels in sporadic and ulcerative-colitis-associated colorectal cancer. However, the effects of VDUP1 deficiency on CAC remain unclear. In this study, we found that VDUP1 deficiency promoted CAC development in mice. Wild-type (WT) and VDUP1 KO mice were used to investigate the role of VDUP1 in the development of azoxymethane (AOM)- and dextran sulfate sodium (DSS)-induced CAC. VDUP1 levels significantly decreased in the colonic tumor and adjacent nontumoral tissues of WT mice after AOM/DSS treatment. Moreover, AOM/DSS-treated VDUP1 KO mice exhibited a worse survival rate, disease activity index, and tumor burden than WT mice. VDUP1 deficiency significantly induced cell proliferation and anti-apoptosis in tumor tissues of VDUP1 KO mice compared to WT littermates. Additionally, mRNA levels of interleukin-6 and tumor necrosis factor-alpha and active forms of signal transducer and activator of transcription 3 and nuclear factor-kappa B p65 were significantly increased in the tumor tissues of VDUP1 KO mice. Overall, this study demonstrated that the loss of VDUP1 promoted AOM/DSS-induced colon tumorigenesis in mice, highlighting the potential of VDUP1-targeting strategies for colon cancer prevention and treatment.

Si-Ni-San alleviates intestinal and liver damage in ulcerative colitis mice by regulating cholesterol metabolism

Ethnopharmacological relevanceSi-Ni-San (SNS), a traditional Chinese medicinal formula derived from Treatise on Febrile Diseases, is considered effective in the treatment of inflammatory bowel diseases based upon thousands of years of clinical practice. However, the bioactive ingredients and underlying mechanisms are still unclear and need further investigation. Aim of the studyThis study aimed to evaluate the effect, explore the bioactive ingredients and the underlying mechanisms of SNS in ameliorating ulcerative colitis (UC) and associated liver injury in dextran sodium sulphate (DSS)-induced mouse colitis models. Materials and methodsThe effect of SNS (1.5, 3, 6 g/kg) on 3% DSS-induced acute murine colitis was evaluated by disease activity index (DAI), colon length, inflammatory cytokines, hematoxylin-eosin (H&E) staining, tight junction proteins expression, ALT, AST, and oxidative stress indicators. HPLC-ESI-IT/TOF MS was used to analyze the chemical components of SNS and the main xenobiotics in the colon of UC mice after oral administration of SNS. Network pharmacological study was then conducted based on the main xenobiotics. Flow cytometry and immunohistochemistry techniques were used to demonstrate the inhibitory effect of SNS on Th17 cells differentiation and the amelioration of Th17/Treg cell imbalance. LC-MS/MS, Real-time quantitative polymerase chain reaction (RT-qPCR), and western blotting techniques were performed to investigate the oxysterol-Liver X receptor (LXRs) signaling activity in colon. Targeted bile acids metabolomics was conducted to reveal the change of the two major pathways of bile acid synthesis in the liver, and the expression of key metabolic enzymes of bile acids synthesis was characterized by RT-qPCR and western blotting techniques. ResultsSNS (1.5, 3, 6 g/kg) decreased the DAI scores, protected intestinal mucosa barrier, suppressed the production of pro-inflammatory cytokines, improved hepatic and splenic enlargement and alleviated liver injury in a dose-dependent manner. A total of 22 components were identified in the colon of SNS (6 g/kg) treated colitis mice, and the top 10 components ranked by relative content were regarded as the potential effective chemical components of SNS, and used to conduct network pharmacology research. The efficacy of SNS was mediated by a reduction of Th17 cell differentiation, restoration of Th17/Treg cell homeostasis in the colon and spleen, and the experimental results were consistent with our hypothesis and the biological mechanism predicted by network pharmacology. Mechanistically, SNS regulated the concentration of 25-OHC and 27-OHC by up-regulated CH25H, CYP27A1 protein expression in colon, thus affected the expression and activity of LXR, ultimately impacted Th17 differentiation and Th17/Treg balance. It was also found that SNS repressed the increase of hepatic cholesterol and reversed the shift of BA synthesis to the acidic pathway in UC mice, which decreased the proportion of non-12-OH BAs in total bile acids (TBAs) and further ameliorated colitis and concomitant liver injury. ConclusionsThis study set the stage for considering SNS as a multi-organ benefited anti-colitis prescription based on the significant effect of ameliorating intestinal and liver damage, and revealed that derivatives of cholesterol, namely oxysterols and bile acids, were closely involved in the mechanism of SNS anti-colitis effect.

Rosa roxburghii Tratt (Cili) has a more effective capacity in alleviating DSS-induced colitis compared to Vitamin C through B cell receptor pathway

Rosa roxburghii Tratt (RRT), a traditional Chinese plant known as the ’King of Vitamin C (VitC; ascorbic acid, AsA)’, contains a wealth of nutrients and functional components, including polysaccharides, organic acids, flavonoids, triterpenes, and high superoxide dismutase (SOD) activity. The various functional components of RRT suggest that it may theoretically have a stronger potential for alleviating colitis compared to VitC. This study aims to verify whether RRT has a stronger ability to alleviate colitis than equimolar doses of VitC and to explore the mechanisms underlying this improvement. Results showed that RRT significantly mitigated body weight loss, intestinal damage, elevated inflammation levels, and compromised barriers in mice induced by Dextran sulfate sodium (DSS). Additionally, RRT enhanced the diversity and composition of intestinal microbiota in these DSS-induced mice. Colon RNA sequencing analysis revealed that compared to VitC, RRT further downregulated multiple immune-related signaling pathways, particularly the B cell receptor (BCR) pathway, which is centered around genes like Btk and its downstream PI3K-AKT, NF-κB, and MAPK signaling pathways. Correlation analysis between microbiota and genes demonstrated a significant relationship between the taxa improved by RRT and the key genes in the BCR and its downstream signaling pathways. Overall, RRT exhibited superior capabilities in alleviating DSS-induced colitis compared to VitC by decreasing intestinal inflammation and modulating BCR and its downstream signaling pathways, potentially regulated by the improved intestinal microbiota.

Dietary Fiber Deficiency Accelerates Colitis in Mice in the Short Term Independent of Short-Chain Fatty Acids

It is believed that short-chain fatty acids (SCFAs)—the bacterial metabolites produced by the digestion of dietary fiber—potentially contribute to the prevention of colitis. However, this beneficial effect has not been conclusively proven. We thus attempted to verify this beneficial effect by examining whether colitis can be caused or worsened by the deficiency in dietary fiber in mice. We found that dextran sodium sulfate (DSS)-induced colitis was accelerated under a fiber-deficient condition, but the fiber deficiency itself did not provoke colitis. Moreover, episodes of diarrhea and epithelium damage in the large intestine were found upon analysis 24 h after the intervention. Unfortunately, these symptoms and tissue damage could not be ameliorated by administering SCFAs. On the other hand, a fiber-deficient condition increased the population of Desulfovibrio spp. and decreased the population of Lactobaccillus spp. regardless of the presence or absence of DSS upon analysis 24 h after the intervention. These results suggest that a deficiency in dietary fiber makes the intestinal environment irritable to colitis-inducing stimuli within the short term. This change does not appear to be related to the presence of SCFAs, but to the alteration of microbiota. Hence, a regular intake of dietary fiber is strongly recommended to avoid colitis and preserve intestinal health.

Alleviation of Antarctic krill oil on dextran sulfate sodium exposure induced chronic ulcerative colitis and depressive-like behavior

Substantial evidence indicate that Antarctic krill oil (KO) is an effective method for alleviating acute ulcerative colitis (UC). Nevertheless, UC is a chronic disease, and the chronic colitis model is more conducive to simulating its pathological characteristics. The objective of this study was to establish a chronic UC model in C57BL/6 mice and identify the regulatory consequences and feasible mechanisms of KO on chronic UC and its associated depressive-like behaviors. The results showed that KO alleviated the pathological features of UC and depression-like behavior. Further mechanisms suggested that KO significantly suppressed gut-brain inflammation, increased the concentration of 5-hydroxytryptamine (5-HT) and the expression of postsynaptic density protein 95 (PSD95) and brain-derived neurotrophic factor (BDNF), protected the integrity of the gut barrier and blood–brain barrier. Moreover, KO maintained the equilibrium of the intestinal flora. The findings suggested that KO may be a promising approach for alleviating UC and its concomitant psychiatric disorders.

Sanguinarine alleviates ulcerative colitis in mice by regulating the Nrf2/NF-κB pathway

To investigate the mechanism of sanguinarine (SA) for alleviating ulcerative colitis (UC) induced by dextran sodium sulfate (DSS) in mice. Male C57BL/6 mouse models of 3.5% DSS-induced UC were randomized for treatment with 1, 5 and 10 mg/kg SA by gavage, 400 mg/kg sulfasalazine by gavage, or 10 mg/kg SA combined with intraperitoneal injection of 30 mg/kg ML385 (a Nrf2 inhibitor). The changes in intestinal inflammation was assessed by monitoring weight changes, disease activity index (DAI) score, colon length measurement, and HE staining. After the treatments, the colon tissues were collected for detection of malondialdehyde (MDA) content using colorimetry, mRNA expressions of inflammatory factors using RT-qPCR, and the expressions of Nrf2, HO-1, Keap-1, p-p65, p65, occludin, and ZO-1 proteins were detected using Western blotting. SA treatment obviously alleviated weight loss, colon length shortening and DAI score increase and ameliorated structural destruction of the colon glands and colonic crypts in mice with DSSinduced UC. SA intervention significantly decreased the levels of TNF-α, IL-1β and IL-6 mRNA and lowered ROS and MDA levels in the colon tissue of UC mice. The mouse models receiving SA treatment showed significantly increased expressions of Nrf2, HO-1, occludin and ZO-1 and lowered expressions of Keap-1 and P-P65 in the colon tissue without significant changes of p65 expression, and these changes were SA dose-dependent. Treatment with ML385 obviously attenuated the effect of highdose SA for improving UC in the mouse models. SA can improve UC-like enteritis in mice possibly by activating the Nrf2 pathway and inhibiting the NF-κB pathway in the colon tissue.

Exploring the relationship between ulcerative colitis, colorectal cancer, and prostate cancer.

Chronic systemic inflammation caused by diseases such as ulcerative colitis (UC) and Crohn's disease (CD) increases the risk of developing colorectal cancer (CRC). Recent evidence indicates that patients with UC are more susceptible to prostate cancer (PCa), and individuals with PCa may also be at a higher risk of developing CRC. However, these relationships are not well defined. A better understanding of this phenomenon could improve the identification of high-risk populations. In this study, we characterized these relationships with experiments using preclinical mouse models of dextran sulfate sodium (DSS)-induced colitis (DSS-UC) and DSS/azoxymethane (AOM)-induced CRC (DSS/AOM-CRC) in wild-type and conditional transgenic mice of PCa. We showed that DSS-induced UC was more severe in mice with PCa and resulted in the development of CRC in the absence of AOM. We further showed that PCa-free mice that developed DSS-induced UC also showed histological changes in the normal prostate that resembled proliferative inflammatory atrophy. Finally, we used immunohistochemical immune profiling to show that mice with PCa-induced chronic systemic inflammation accumulated Gr1+ myeloid cells in the normal colon and exposure to DSS further enriched these cells in active colitis regions and colon tumors. Our study provides evidence to support a link between systemic chronic inflammation and cancer.

The inhibitory effects of the novel Lactobacillus cocktail on colorectal cancer development through modulating BMP signaling pathway: In vitro and in vivo study

This study investigates the impact of a five-strain Lactobacillus cocktail (comprising two strains of L. plantarum, and one strain each of L. brevis, L. reuteri, and L. rhamnosus) on colorectal cancer (CRC) modulation by targeting the bone morphogenetic proteins (BMP) signaling pathway. Both in vitro and in vivo (models were employed. The antiproliferative effects of the Lactobacillus cocktail on HT-29 cells were assessed via the MTT assay. Mice were divided into three groups: a negative control (treated with PBS), a positive control (treated with azoxymethane (AOM)/dextran sulfate sodium (DSS) + PBS), and a test group (treated with AOM/DSS + Lactobacillus cocktail in PBS). The role of the Lactobacillus cocktail in inhibiting the BMP signaling pathway was evaluated using qRT-PCR for gene expression analysis and western blotting for β-catenin protein assessment in both models. The MTT assay results demonstrated a significant, time-dependent reduction in HT-29 cell proliferation. qRT-PCR indicated downregulation of the BMP signaling pathway in treated cells, which subsequently led to decreased expression of the hes1 gene, crucial for cell differentiation and proliferation control. This inhibitory effect was corroborated in the mice model, showing significant downregulation of BMP pathway genes and hes1 in the AOM/DSS/Lactobacillus cocktail-treated group. Additionally, western blotting revealed a marked decrease in β-catenin expression in both in vitro and in vivo experiments. Collectively, these findings suggest that the Lactobacillus cocktail may aid in CRC prevention by downregulating the BMP signaling pathway.

Effects of the N-Butanol Extract of Pulsatilla Decoction on Neutrophils in a Mouse Model of Ulcerative Colitis.

Ulcerative colitis (UC) is a chronic inflammatory disease, the incidence of which is increasing worldwide. However, the etiology and pathogenesis of UC remains unclear. The n-butanol extract of Pulsatilla decoction (BEPD), a traditional Chinese medicine, has been shown to be effective in treating UC. This study aimed to explore the molecular mechanism underlying the effects of BEPD on UC, in particular its effects on neutrophil extracellular trap (NET) formation by neutrophils. High-performance liquid chromatography was used to determine the principal compounds of BEPD. UC was induced in mice using dextran sodium sulfate, and mice were treated with 20, 40, or 80 mg/kg BEPD daily for seven days. Colonic inflammation was determined by assessing the disease activity index, histopathology, colonic mucosal damage index, colonic mucosal permeability, and pro- and anti-inflammatory cytokine levels. The infiltration and activation status of neutrophils in the colon were determined by analyzing the levels of chemokine (C-X-C motif) ligand (CXCL) 1 and CXCL2, reactive oxygen species, Ly6G, and numerous NET proteins. The findings suggest that BEPD improved the disease activity index, histopathology, and colonic mucosal damage index scores of mice with UC, and restored colonic mucosal permeability compared with untreated mice. The expression levels of the pro-inflammatory cytokines interleukin-1β, interleukin-6, and tumor necrosis factor-α in colon tissues were significantly decreased, while the expression levels of anti-inflammatory cytokines in colon tissues were significantly increased, exceeding those of control mice. In addition, BEPD reduced the expression of the neutrophil chemokines CXCL1 and CXCL2 in the colon tissue of mice with UC, reduced neutrophil infiltration, reduced reactive oxygen species levels, and significantly reduced the expression of NET proteins. BEPD also significantly reduced NET formation. The results of this study suggest that BEPD exerts therapeutic effects in a murine model of UC by inhibiting neutrophil infiltration and activation in the colon, as well as by inhibiting the expression of key proteins involved in NET formation and reducing NET formation, thereby alleviating local tissue damage and disease manifestations.

Network pharmacology and experimental verification revealing valnemulin alleviates DSS-induced ulcerative colitis by inhibiting intestinal senescence

Ulcerative colitis (UC) is a chronic inflammatory disease that is increasing in prevalence globally. Senescence is characterized by a specific chronic, low-grade, “sterile” inflammatory state known as inflammaging, suggesting that senescence may exacerbate the severity of UC. However, the link between UC and senescence remains unclear. Valnemulin (VAL) is a semi-synthetic derivative of a naturally occurring diterpenoid antibiotic (pleuromutilin), which can inhibit peptidyl transferase. Studies investigating the potential of valnemulin to inhibit senescence and alleviate colitis are currently limited. In this study, we revealed that dextran sulfate sodium (DSS), an inducer of UC, induces senescence in both colon epithelial NCM460 cells and colon tissues. Additionally, VAL, identified from a compound library, exhibited robust anti-senescence activity in DSS-treated NCM460 cells. Identified in our study as an anti-senescence agent, VAL effectively mitigated DSS-induced UC and colonic senescence in mice. Through network pharmacology analysis and experimental validation, the potential signaling pathway (AMPK/NF-κB) for VAL in treating UC was identified. We discovered that DSS significantly inhibited the AMPK signaling pathway and activated the NF-κB signaling pathway. However, supplementation with VAL remarkably restored AMPK activity and inhibited the NF-κB signaling pathway, which led to the inhibition of senescence. In summary, our study demonstrated that DSS-induced UC stimulates the senescence of colonic tissues, and VAL can effectively alleviate DSS-induced colonic damage and reduce colonic senescence. Our research findings provide a new perspective for targeting anti-senescence in the treatment of UC.

Isoorientin ameliorated ulcerative colitis by inhibiting the Galectin-3/NLRP3/IL-1β signaling pathway

Isoorientin (Iso) is a natural flavonoid present in the human diet, known for its anti-inflammatory, antioxidant, and antiviral properties. The purpose of this research was to illustrate the anti-inflammatory potential of Iso in ulcerative colitis (UC) mice and elucidate potential mechanisms. The mice model of UC was induced by cyclic intervention with Dextran Sulfate Sodium (DSS). We evaluated the efficacy of Iso in the treatment of UC, detected the expression of proteins related to the Galectin-3/NLRP3/IL-1β signaling pathway, and assessed the intestinal mucosa barrier function of colon tissue. Our findings demonstrated that Iso could improve colon length, the index of colonic weight, pathological damage to the colon, and serum cytokine secretion of UC mice. Most importantly, Iso could competitively bind Galectin-3, inhibit the interaction of Galectin-3 with NLRP3 and the expression of Galectin-3, NLRP3, ASC, caspase-1, IL-1β, and IL-18, increase the expression of MUC2, Occludin, and ZO-1. In summary, Iso had a therapeutic effect on UC mice, and its mechanism may be to inhibit the inflammatory response and improve the intestinal mucosa barrier by binding Galectin-3 and inhibiting the Galectin-3/NLRP3/IL-1β signaling pathway.

Amelioration effects of chlorogenic acid on mice colitis: Anti-inflammatory and regulation of gut flora

This research endeavors to investigate the potential preventive and protective effects of chlorogenic acid (CGA), a bioactive component found in various foods, in the context of dextran sodium sulfate (DSS)-induced colitis in mice. The study reveals that CGA administration, at dosages of 150 and 300 mg/kg, significantly retards the progression of colitis. This is substantiated by observable enhancements in colon length, reduction in the disease activity index, and mitigation of colon tissue damage. Meanwhile, CGA acts as an antioxidant by reducing the oxidative stress associated with colitis inflammation and increasing the activity of antioxidant enzymes. Furthermore, CGA demonstrates anti-inflammatory properties by inhibiting the inflammatory response associated with colitis and regulating the excessive expression of cytokines. Notably, CGA contributes to the restoration of intestinal barrier function by augmenting the levels of claudin-1 and ZO-1. Moreover, the investigation uncovers CGA's capacity to modulate the gut microbiota composition in colitic mice, fostering the proliferation of beneficial bacteria, notably Lactobacillus, while concurrently impeding the growth of detrimental bacteria like Bacteroides, Enterobacteriaceae, and Escherichia_Shigella. To conclude, these findings substantiate the viability of CGA for diverse applications in the realms of food and medicine, thereby bolstering its potential as a therapeutic strategy within dietary interventions.

Impact of Nanoplastic Particles on Macrophage Inflammation and Intestinal Health in a Mouse Model of Inflammatory Bowel Disease.

The increasing presence of plastics in the human diet is raising public concern about the potential risks posed by nanoplastic (NP) particles, which can emerge from the degradation of plastic debris. NP ingestion poses particular risks to individuals with inflammatory bowel disease (IBD), as compromised epithelial barriers may facilitate NP translocation. In vitro, bone-marrow-derived macrophages (BMDMs) were exposed to 25 nm polymethacrylate (PMMA) or 50 nm polystyrene (PS) particles to assess morphological changes and alterations in pro- and anti-inflammatory gene expression. In vivo, mice received PMMA NP particles for 6 months before acute dextran sodium sulfate (DSS) colitis was induced to investigate NP impacts on intestinal health and inflammation. PMMA and PS NP exposure in BMDMs induced morphological changes indicative of a proinflammatory phenotype characterized by enlarged amoeboid cell shapes. It also triggered an inflammatory response, indicated by increased expression of proinflammatory cytokines such as Tnfa and Il6. Unexpectedly, long-term PMMA NP administration did not affect the intestinal epithelial barrier or exacerbate acute DSS-induced colitis in mice. Colonoscopy and histological analysis revealed no NP-related changes, suggesting adverse effects on intestinal health or inflammation. Our findings from animal models offer some reassurance to IBD patients regarding the effects of NP ingestion. However, variations in lifestyle and dietary habits may lead to significantly higher plastic intake in certain individuals, raising concerns about potential long-term gastrointestinal effects of lifelong plastic consumption.

Integration of microbiome, metabolomics and transcriptome for in-depth understanding of berberine attenuates AOM/DSS-induced colitis-associated colorectal cancer

A type of colorectal cancer (CRC)，Colitis-associated colorectal cancer (CAC)， is closely associated with chronic inflammation and gut microbiota dysbiosis. Berberine (BBR) has a long history in the treatment of intestinal diseases, which has been reported to inhibit colitis and CRC. However, the mechanism of its action is still unclear. Here, this study aimed to explore the potential protective effects of BBR on azoxymethane (AOM)/dextransulfate sodium (DSS)-induced colitis and tumor mice, and to elucidate its potential molecular mechanisms by microbiota, genes and metabolic alterations. The results showed that BBR inhibited the gut inflammation and improved the function of mucosal barrier to ameliorate AOM/DSS-induced colitis. And BBR treatment significantly reduced intestinal tumor development and ki-67 expression of intestinal tissue along with promoted apoptosis. Through microbiota analysis based on the 16 S rRNA gene, we found that BBR treatment improved intestinal microbiota imbalance in AOM/DSS-induced colitis and tumor mice, which were characterized by an increase of beneficial bacteria, for instance Akkermanisa, Lactobacillus, Bacteroides uniformis and Bacteroides acidifaciens. In addition, transcriptome analysis showed that BBR regulated colonic epithelial signaling pathway in CAC mice particularly by tryptophan metabolism and Wnt signaling pathway. Notably, BBR treatment resulted in the enrichment of amino acids metabolism and microbiota-derived SCFA metabolites. In summary, our research findings suggest that the gut microbiota-amino acid metabolism-Wnt signaling pathway axis plays critical role in maintaining intestinal homeostasis, which may provide new insights into the inhibitory effects of BBR on colitis and colon cancer.

Effect of Mutant and Engineered High-Acetate-Producing Saccharomyces cerevisiae var. boulardii Strains in Dextran Sodium Sulphate-Induced Colitis.

Acetate-producing Saccharomyces cerevisiae var. boulardii strains could exert improved effects on ulcerative colitis, which here, was preclinically evaluated in an acute dextran sodium sulphate induced model of colitis. Nine-week-old female mice were divided into 12 groups, receiving either drinking water or 2.75% dextran sodium sulphate for 7 days, combined with a daily gavage of various treatments with different levels of acetate accumulation: sham control (phosphate buffered saline, no acetate), non-probiotic control (Baker's yeast, no acetate), probiotic control (Enterol®, transient acetate), and additionally several Saccharomyces cerevisiae var. boulardii strains with respectively no, high, and extra-high acetate accumulation. Disease activity was monitored daily, and feces samples were collected at different timepoints. On day 14, the mice were sacrificed, upon which blood and colonic tissue were collected for analysis. Disease activity in inflamed mice was lower when treated with the high-acetate-producing strain compared to sham and non-probiotic controls. The non-acetate-producing strain showed higher disease activity compared to the acetate-producing strains. Accordingly, higher histologic inflammation was observed in non- or transient-acetate-producing strains compared to the sham control, whereas this increase was not observed for high- and extra-high-acetate-producing strains upon induction of inflammation. These anti-inflammatory findings were confirmed by transcriptomic analysis of differentially expressed genes. Moreover, only the strain with the highest acetate production was superior in maintaining a stable gut microbial alpha-diversity upon inflammation. These findings support new possibilities for acetate-mediated management of inflammation in inflammatory bowel disease by administrating high-acetate-producing Saccharomyces cerevisae var. boulardii strains.

Portulaca oleracea L. polysaccharide ameliorates ulcerative colitis by regulating the immune system and gut microbiota

This study aims to clarify the characteristics of the water-soluble polysaccharide from Portulaca oleracea L. (POL-P) and further explore its potential mechanism on ulcerative colitis (UC). POL-P was prepared and identified by gel permeation chromatography (GPC), high-performance liquid chromatography (HPLC), and scanning electron microscopy (SEM). The protective effect of POL-P was evaluated in a mouse model of UC induced by dextran sulfate sodium (DSS). Under the premise of confirming the efficacy of POL-P, we performed an integrated approach of transmission electron microscopy (TEM), fluorescence-activated cell sorting (FACS), enzyme-linked immunosorbent assay (ELISA), and 16S rRNA high-throughput sequencing to explore the effects of POL-P on the intestinal immunity and intestinal flora structure of UC mice and to further analyzed the related mechanism of POL-P in alleviating UC. ResultsThe molecular weight of POL-P was 40 kDa. POL-P contained mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, and arabinose, with a molar ratio of 1.2:13.2:33.5:1.2:3.3:32.2:15.4. The in vivo efficacy results showed that 0.8 g/kg POL-P significantly ameliorated colonic pathological damage and alleviated colon inflammation by improving the blood status and regulating the levels of IL-6, IL-17, TNF-α, and IL-10. Additionally, POL-P decreased specific immune responses, which was attributed to inhibiting the function of dendritic cells and balancing T-lymphocyte subsets. Furthermore, POL-P suppressed pathogens and ameliorated DSS-induced microbiota dysbiosis. ConclusionPOL-P functions as a novel polymer compound to alleviate UC by regulating immune and gut microbiota.

Tocilizumab unfolds colo-protective and immunomodulatory effect in experimentally induced ulcerative colitis via mitigating autophagy and ER stress signaling

Ulcerative colitis (UC) is an idiopathic, chronic, relapsing inflammatory bowel disease (IBD), characterized by chronic inflammation of the gastrointestinal tract. The pathophysiology of UC is complicated and involves several factors including immune, genetic, and environmental factors. Recently, a huge amount of research has concentrated on the role of interleukins including interleukin-6 (IL-6) in its pathophysiology. Thus, this study aims to examine the colo-protective and immunomodulatory effect of Tocilizumab (TCZ) in an experimental model of dextran sulfate sodium (DSS) induced UC. In the current study, we analyzed the inflammatory, immunomodulatory, apoptotic, autophagy, and endoplasmic reticulum (ER) stress markers and other clinical features including stool consistency, rectal bleeding, and edema markers in rats. Our results showed that induction of colitis caused bloody diarrhea and increased IL-6 levels. Treatment with TCZ significantly ameliorated DSS-induced injury via decreasing inflammatory markers of colon injury (IL-6), signal transducer and activator of transcription-3 (STAT-3), and C-reactive protein (CRP). Furthermore, TCZ attenuated the apoptotic marker (caspase-3), and down-regulated endoplasmic reticulum stress sensor proteins (inositol- requiring transmembrane kinase endonuclease-1 (IRE-1) and activated transcription factor-6 (ATF-6)) and autophagy proteins (autophagy-related 16-like protein 1 (ATG16L1) and nucleotide-binding oligomerization domain-containing protein-2 (NOD2)), as compared to DSS group. Altogether, the current data suggest TCZ to be a promising protective therapy against UC.Graphical

The beneficial impact of ketogenic diets on chemically-induced colitis in mice depends on the diet's lipid composition

Previously, we showed that restrictive diets, including ketogenic diet (KD), have an anti-inflammatory impact on the healthy gastrointestinal tract of mice. Afterward, we found that energy-restricting diets mitigate inflammation in the dextran sodium sulfate (DSS) colitis mouse model. The current study aimed to verify the impact of KD on DSS colitis and assess if the diet's fat composition influences the outcomes of the intervention.Mice with mild chronic colitis were fed control chow, KD composed of long-chain triglycerides (KD LCT) or a KD containing a mix of LCT and medium-chain triglycerides (KD LCT/MCT).KDs did not reverse DSS-enhanced gut permeability and shortening of the colon. Both KDs had a similar impact on liver, cecum, and spleen weight, villi and colon length, the thickness of muscularis externa, and expression of ZO-1 and occludin. On the contrary, body weight, glutathione (GSH) and taurine-GSH levels, GSH-S transferase (GST), and myeloperoxidase (MPO) activity, as well as an abundance of several fecal bacteria, all were differentially affected by the two types of KDs. When compared to the DSS control diet, reduction in colon mucosa cytokines expression was stronger in KD LCT than in the KD LCT/MCT group.We conclude that the outcomes of the KD interventions in terms of potential therapeutical applications depend on lipid composition. KD LCT showed a strong positive impact on gut inflammation. A potential contribution of GSH to KD outcomes and a correlation between MPO activity and microbiota composition was identified.

Dietary Porphyra tenera ameliorated dextran sodium sulfate-induced colitis in mice via modulating gut microbiota dysbiosis

Bioactive components from Porphyra tenera (PT) have been reported to confer various health benefits. The role of PT in inflammatory bowel disease (IBD) has not been fully investigated. This study aimed to explore the anti-inflammatory properties of PT on dextran sodium sulfate (DSS)-treated mice. PT supplementation attenuated the severity of colitis in DSS-treated mice, evidenced by the reduction of disease activity index (DAI), restoration of colonic histological damage and suppression of abnormal inflammatory response. Sequencing analysis indicated that intake of PT alleviated DSS-induced gut microbiota dysbiosis, accompanied by reversing the generation of short-chain fatty acids (SCFAs) and bile acids (BAs). Overall, our findings demonstrated that supplementation of PT attenuated the severity of intestinal inflammation and ameliorated gut microbiota dysbiosis in a murine colitis model, which provided a rationale for further application of edible seaweeds for preventing inflammation-related disorders in humans.

Class A1 scavenger receptor antibody improves murine colitis by influencing macrophage and gut microbiota

This study aimed to investigate whether class A1 scavenger receptor (SR-A1) regulated macrophage polarization and gut microbial alteration during intestinal inflammation of colitis. A murine colitis model was established by feeding with dextran sulfate sodium (DSS), and treatment groups were injected intravenously with SR-A1 antibody. Results showed a preventive effect on colitis symptoms and fewer inflammatory cell infiltrates in treatment groups. Down-regulation of inflammatory cytokines and up-regulation of anti-inflammatory cytokine related to macrophages were seen in murine PBMC and LPMC after injected with SR-A1 antibody. The percentage of M2 macrophages was also elevated in treatment groups. In addition, SR-A1 antibody treatment resulted in the decreased apoptosis and increased proliferation of colonic epithelial cells. Other findings indicated that SR-A1 antibody injection could mediate its anti-inflammatory effect via inhibiting TLR4-MyD88-NF-kB signaling pathway and alterating the gut microbiota composition. Our research identified SR-A1 as a potential therapeutic target in inflammatory bowel disease (IBD).