Colitis In Mice Research Articles

ChiA: a major player in the virulence of Crohn’s disease-associated adherent and invasive Escherichia coli (AIEC)

ABSTRACT We investigated the role of ChiA and its associated polymorphisms in the interaction between Crohn’s disease (CD)-associated adherent-invasive Escherichia coli (AIEC) and intestinal mucosa. We observed a higher abundance of chiA among the metagenome of CD patients compared to healthy subjects. In dextran sulfate sodium-induced colitis mice model, AIEC-LF82∆chiA colonization was reduced in ileal, colonic and fecal samples compared to wild-type LF82. The binding of ChiA to recombinant human CHI3L1 or mucus was higher with the pathogenic polymorphism. The strength of ChiA-mucin interaction was 300-fold stronger than ChiA-rhCHI3L1. ChiA was able to degrade mucin to promote its growth and enabled LF82 to get closer to epithelial cells. The pathogenic polymorphism of ChiA had a stronger impact on mucus degradation than on the binding capability of AIEC to adhere to the intestinal epithelium. We observed that ChiA could favor an efficient bacterial invasion of intestinal crypts, and that ChiA, especially its pathogenic polymorphism, gives LF82 an advantage to uptake within Peyer’s patches, macrophages and mesenteric lymph nodes. All together, these data support the role of ChiA in the virulence of AIEC and show that it could be a promising target to reduce AIEC colonization in patients with CD.

A pH-sensitive opioid does not exhibit analgesic tolerance in a mouse model of colonic inflammation.

Tolerance to the analgesic effects of opioids and resultant dose escalation is associated with worsening of side effects and greater addiction risk. Here, we compare the development of tolerance to the conventional opioid fentanyl with a novel pH-sensitive μ-opioid receptor (MOR) agonist, (±)-N-(3-fluoro-1-phenethylpiperidine-4-yl)-N-phenyl propionamide (NFEPP) that is active only in acidic inflammatory microenvironments. An opioid tolerance model was developed in male C57BL/6 mice, with and without dextran sulphate sodium colitis, using increasing doses of either fentanyl or NFEPP over 5 days. Visceral nociception was assessed in vivo by measuring visceromotor responses (VMRs) to noxious colorectal distensions and in vitro measuring colonic afferent nerve activity of mesenteric nerves and performing patch-clamp recordings from isolated dorsal root ganglia neurons. Somatic thermal nociception was tested using a tail immersion assay. Cardiorespiratory effects were analysed by pulse oximeter experiments. VMRs and tail immersion tests demonstrated tolerance to fentanyl, but not to NFEPP in colitis mice. Cross-tolerance also occurred to fentanyl, but not to NFEPP. The MOR agonist DAMGO inhibited colonic afferent nerve activity in colitis mice exposed to chronic NFEPP, but not those from fentanyl-treated mice. Similarly, in patch-clamp recordings from isolated dorsal root ganglia neurons, DAMGO inhibited neurons from NFEPP-, but not fentanyl-treated mice. NFEPP did not exhibit tolerance in an inflammatory pain model, unlike fentanyl. Consequently, dose escalation to maintain analgesia during an evolving inflammation could be avoided, mitigating the potential risk of side effects.

Dietary Dihydroquercetin Alleviated Colitis via the Short-Chain Fatty Acids/miR-10a-5p/PI3K-Akt Signaling Pathway.

Gut microbiota provides an important insight into clarifying the mechanism of active substances with low bioavailability, but its specific action mechanism varied case by case and remained unclear. Dihydroquercetin (DHQ) is a bioactive flavonoid with low bioavailability, which showed beneficial effects on colitis alleviation and gut microbiota modulation. Herein, we aimed to explore the microbiota-dependent anticolitis mechanism of DHQ in sight of gut microbiota metabolites and their interactions with microRNAs (miRNAs). Dietary supplementation of DHQ alleviated dextran sulfate sodium-induced colitis phenotypes and improved gut microbiota dysbiosis. Fecal microbiota transplantation further revealed that the anticolitis activity of DHQ was mediated by gut microbiota. To clarify how the modulated gut microbiota alleviated colitis in mice, the tandem analyses of the microbiome and targeted metabolome were performed, and altered profiles of metabolite short-chain fatty acids (SCFAs) and bile acids and their producers were observed in DHQ-treated mice. In addition, SCFA treatment showed anticolitis activity compared to that of bile acids, along with the specific inhibition on the phosphoinositide-3-kinase (PI3K)-protein kinase B (Akt) pathway. Subsequently, the colonic miRNA profile of mice receiving SCFA treatment was sequenced, and a differentially expressed miR-10a-5p was identified. Both prediction analysis and dual-luciferase reporter assay indicated that miR-10a-5p directly bind to the 3'-untranslated regions of gene pik3ca, inhibit the PI3K-Akt pathway activation, and lead to colitis alleviation. Together, we proposed that gut microbiota mediated the anticolitis activity of DHQ through the SCFAs/miR-10a-5p/PI3K-Akt axis, and it provided a novel insight into clarifying the microbiota-dependent mechanism via the interaction between metabolites and miRNAs.

Cordycepin mitigates dextran sulfate sodium-induced colitis through improving gut microbiota composition and modulating Th1/Th2 and Th17/Treg balance

BackgroundImbalances in Th1/Th2 and Th17/Treg immune axes, coupled with disruptions in the gut microbiota (GM), play a pivotal role in the pathogenesis of inflammatory bowel disease (IBD). Cordycepin, a natural anti-inflammatory compound, holds promise in mitigating IBD by rebalancing these immune axes in conjunction with modulating the GM. The aim of this experiment is to investigate the potential of cordycepin in mitigating enteritis and elucidate the underlying mechanisms associated with its ameliorative effects on enteritis. MethodsOn the day of inducing experimental colitis with Dextran Sulfate Sodium (DSS), mice in the DSS + Cordycepin and Cordycepin groups received 50 mg/kg/day Cordycepin via intra-gastric administration (i.g.) for seven consecutive days, respectively. Mice in the DSS and control groups were treated with equal volumes of saline. On day 8, all mice were euthanized under pentobarbital sodium anesthesia. ResultsIn a DSS-induced colitis mouse model, Cordycepin treatment led to a significant reduction in the disease activity index (DAI), splenic weight, and colonic pathological injury while simultaneously improving body weight and colonic length. Furthermore, it positively impacted GM composition, resulting in decreased Th1 and Th17 cells, alongside an increase in Th2 and Treg cells. The contents of the mouse colon were extracted for microbial community analysis. Mouse blood was prepared into a single-cell suspension, and flow cytometry was used to assess the expressio of Treg, Th17, Th1, and Th2 immune cells. ConclusionsThese results underscored the effective intervention of cordycepin in ameliorating DSS-induced colitis by harmonizing the interplay between GM and immune homeostasis.

Goat Milk Exosomes Ameliorate Ulcerative Colitis in Mice through Modulation of the Intestinal Barrier, Gut Microbiota, and Metabolites.

Goat milk is rich in a variety of nutrients that are important for intestinal health and disease prevention. However, the role of exosomes in goat milk remains to be elucidated. This study investigated for the first time the therapeutic efficacy and molecular underlying mechanisms of mature milk exosomes (M-exo) and goat colostrum exosomes (C-exo) on dextran sodium sulfate-induced ulcerative colitis (UC) in mice. The findings demonstrate that M-exo and C-exo significantly improved physiological indices, suppressed the secretion of proinflammatory cytokines, and diminished oxidative stress and apoptosis in UC mice. Moreover, C-exo and M-exo restored the intestinal barrier function, remodeled the gut microbiota, and improved metabolite composition in the feces of colitis mice. In conclusion, goat milk exosomes ameliorate UC in mice, which provides a basis for the development of functional food applications for the prevention and treatment of inflammatory bowel disease.

The Role of Dicrocoelium dendriticum Egg Antigen in Colitis: A Molecular, Pathological and Serological Study in an Experimental Model of C57BL/6 Mice.

Inflammatory bowel disease (IBD) is a chronic and recurrent disease of the gastrointestinal tract that enhances the chance of developing colorectal cancer. Since standard treatments such as Mesalazine have limited effectiveness and are often accompanied by numerous side effects, the use of immune modulators derived from worms has been proposed as a new immunotherapy method for inflammatory diseases such as ulcerative colitis. The aim of this study is to investigate the protective effects of D. dendriticum egg antigen on DSS-induced colitis in C57BL/6 mice. D. dendriticum egg antigen was extracted and DSS (3.5%) was used to induce colitis in mice. Treatment and prophylaxis included intraperitoneal injections of D. dendriticum egg antigen. Histopathological indicators and the disease activity index (DAI), including weight loss, rectal bleeding, stool consistency, and rectal prolapse, were used to assess the severity of colitis. Real-time PCR measured the expression of transforming growth factor-β (TGF-β) and interleukin-17 (IL-17), while ELISA determined the concentration of these cytokines. Treatment with D. dendriticum egg antigen significantly improved the clinical symptoms and decreased the severity of DSS-induced colitis. Furthermore, D. dendriticum egg antigen increased the expression of TGF-β mRNA and reduced the expression of IL-17 mRNA, leading to a positive adjustment in the regulation of proteins and reduction of inflammatory proteins. As a result, the macroscopic, microscopic inflammation and activity index (DAI) of DSS-induced decreased. D. dendriticum egg antigen provides a promising new way to modulate the immune system and improve ulcerative colitis.

Zinc pyrithione ameliorates colitis in mice by interacting on intestinal epithelial TRPA1 and TRPV4 channels

AimsAlthough zinc pyrithione (ZPT) has been studied as topical antimicrobial and cosmetic consumer products, little is known about its pharmacological actions in gastrointestinal (GI) health and inflammation. Our aims were to investigate the effects of ZPT on transient receptor potential (TRP) channels and Ca2+ signaling in intestinal epithelial cells (IECs) and its therapeutic potential for colitis. Main methodsDigital Ca2+ imaging and patch-clamp electrophysiology were performed on human colonic epithelial cells (HCoEpiC) and rat small intestinal epithelial cells (IEC-6). The transcription levels of proinflammatory cytokines such as IL-1β were detected by RTq-PCR. Dextran sulfate sodium (DSS) was used to induce colitis in mice. Key findingsZPT dose-dependently induced Ca2+ signaling and membrane currents in IECs, which were attenuated by selective blockers of transient receptor potential ankyrin 1 (TRPA1) and transient receptor potential vanilloid 4 (TRPV4) channels, respectively. Interestingly, Ca2+ entry via TRPA1 channels inhibited the activity of TRPV4 channels in HCoEpiC, but not vice versa. ZPT significantly promoted migration of IECs by activating TRPA1 and TRPV4 channels. ZPT reversed lipopolysaccharides (LPS)-induced changes in mRNA expression of TRPA1 and TRPV4. Moreover, ZPT decreased mRNA levels of pro-inflammatory factors promoted by LPS in HCoEpiC, which were restored by selective TRPA1 blocker. In whole animal studies in vivo, ZPT significantly ameliorated DSS-induced body weight loss, colon shortening and increases in stool score, serum calprotectin and lactic acid (LD) in mouse model of colitis. SignificanceZPT exerts anti-colitic action likely by anti-inflammation and pro-mucosal healing through TRP channels in IECs. The present study not only expands pharmacology spectrum of ZPT in GI tract, but also repurposes it to a potential drug for colitis therapy.

Intestinal barrier, immunity and gut microbiota-based protective effects of Lactococcus lactis HF08 and its postbiotic derivative on aging and aging colitis mice

The prevalence and severity of gastrointestinal diseases were increased with age. In this study, the intestinal protective effects of Lactococcus lactis HF08 (HF08) and its derived postbiotic (P-HF08) on D-gal-induced aging mice and D-gal/DSS-induced aging colitis mice were investigated. In D-gal-induced aging mice, both HF08 and P-HF08 alleviated aging-related intestinal barrier dysfunction, inflammatory status, and gut microbiota disorder. The effects of probiotic HF08 were superior to those of postbiotic P-HF08, attributed to ability of HF08 to regulate the gut microbiota. However, in D-gal/DSS-induced aging colitis mice, the effects of P-HF08 on colitis surpassed that of HF08. Specifically, both HF08 and P-HF08 could reduce symptoms of age-related colitis, including reduction of lose weight, the DAI score, colonic shortening, and colon tissue damage. The inhibitory effects of P-HF08 on intestinal inflammation surpassed those of HF08, as evidenced by the levels of colon IL-6, IL-1β, and IL-10. Western blot results demonstrated that the anti-inflammatory effects of P-HF08 were attributed to the downregulation of key proteins in the TLR4/NF-κB pathway. And four potential TLR4 inhibitors were identified from HF08 metabolites (eplerenone, genistein, indoleacrylic acid, and turanose) by molecular docking. Nevertheless, HF08 could better regulate gut microbiota and metabolite in aging-related colitis than P-HF08, which was consistent with the results on aging mice. Overall, our finding revealed that when the intestinal barrier was intact (aging), probiotics showed superior regulation of intestinal microbiota, while postbiotics offered greater safety in case of intestinal barrier damage (aging colitis). This study offered a novel perspective into the applications of probiotics and their derivatives in the aging related gastrointestinal diseases adjuvant therapy.

Curcumin Attenuates Dextran Sodium Sulfate Induced Colitis in Obese Mice.

Curcumin (Cur), with diverse pharmacological properties, shows anti-obesity, immunomodulatory, and anti-inflammatory effects. Its role in ulcerative colitis complicated by obesity remains unclear. Here, colitis is induced in obese mice using dextran sulfate sodium (DSS), followed by administration of Cur at a dosage of 100mg kg-1 for 14 days. Cur effectively alleviates DSS-induced colitis in obese mice, accompanied by an increase in body weight and survival rate, reduction in disease activity index, elongation of the colon, decrease in colonic weight, and improvements in ulcer formation and inflammatory cell infiltration in colonic tissues. Additionally, Cur effectively improves lipid metabolism and the composition of the gut microbiota, and enhances mucosal integrity and boosts anti-oxidative stress capacity in obese mice with colitis. Importantly, Cur is effective in improving the homeostasis of memory T cells in obese mice with colitis. Furthermore, Cur regulates inflammatory cytokines expression and inhibits activation of the JAK2/STAT signaling pathway in colonic tissues of obese mice with colitis. Cur alleviates colitis in obese mice through a comprehensive mechanism that improves lipid metabolism, modulates gut microbiota composition, enhances mucosal integrity and anti-oxidative stress, balances memory T cell populations, regulates inflammatory cytokines, and suppresses the JAK2/STAT signaling pathway.

The protective effect of Amitriptyline on experimental colitis through inhibiting TLR4/MD2 signaling pathway.

Amitriptyline, a pleiotropic tricyclic antidepressant, possesses anti-oxidant and anti-inflammatory properties. Despite its diverse benefits, the specific effects of amitriptyline on IBD are not yet well defined. To explore this, we utilized a 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 improvements in body weight retention, reductions in DAI, lessening of colon length shortening, and repair 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 TNF-α, IL-1β, and IL-6. Additionally, RNA sequencing analysis pointed to the potential involvement of the TLR pathway in the anti-colitic effects induced by amitriptyline. Subsequent Western blot analysis indicated that amitriptyline significantly inhibited the TLR4-mediated NF-κB signaling pathway. To bolster our findings, in vitro studies demonstrated that amitriptyline down-regulated the TLR4/NF-κB/MAPK signaling cascades in mouse macrophages stimulated with LPS. Further molecular investigations revealed that amitriptyline was able to suppress the elevated expression of MD-2 that LPS stimulation typically induces. In summary, our findings suggest that amitriptyline effectively mitigates DSS-induced colitis in mice through the inhibition of TLR4/MD-2 pathway signaling, indicating its potential repurposing for IBD treatment. Significance Statement The potential of utilizing amitriptyline in treating IBD appears promising, leveraging its established safety and dosing profile as an antidepressant. Our observations show that amitriptyline can alleviate pathological symptoms, inflammation, and intestinal mucosal damage in mice with colitis induced by DSS. The protective effect observed appear to be linked to the inhibition of the TLR4/MD2 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.

Oral administration of Sophora Flavescens-derived exosomes-like nanovesicles carrying CX5461 ameliorates DSS-induced colitis in mice.

Ulcerative colitis (UC) belongs to chronic inflammatory disease with a relapsing characterization. Conventional oral drugs of UC are restricted in clinical by premature degradation in the gastrointestinal tract, modest efficacy, and adverse effects. CX5461 can treat autoimmune disease, immunological rejection, and vascular inflammation. However, low solubility, intravenous administration, and non-inflammatory targeting limited its clinical application. Herein, this work aims to develop Sophora Flavescens-derived exosomes-like nanovesicles carrying CX5461 (SFELNVs@CX5461) for efficient CX5461 oral delivery for UC therapy. We identified SFELNVs as nano-diameter (80nm) with negative zeta potential (-32mV). Cellular uptake has shown that SFELNVs were targeted uptake by macrophages, thus increasing drug concentration. Additionally, oral SFELNVs@CX5461 exhibited good safety and stability, as well as inflammation-targeting ability in the gastrointestinal tract of dextran sodium sulfate (DSS)-induced colitis mice. In vivo, oral administration of SFELNVs and CX5461 could relieve mice colitis. More importantly, combined SFELNVs and CX5461 alleviated mice colitis by inhibiting pro-inflammatory factors (TNF-α, IL-1β, and IL-6) expression and promoting M2 macrophage polarization. Furthermore, SFELNVs promoted M2 polarization by miR4371c using miRNA sequencing. Our results suggest that SFELNVs@CX5461 represents a novel orally therapeutic drug that can ameliorate colitis, and a promising targeting strategy for safe UC therapy.

Effects of Pine Pollen Polysaccharides and Sulfated Polysaccharides on Ulcerative Colitis in Mice by Regulating Th17/Treg.

This study was to investigate the effects of the polysaccharides (PPM60-III) and sulfated polysaccharides (SPPM60-III) of pine pollen on the Th17/Treg balance, inflammatory cytokines, intestinal microbiota, and metabolite distribution in 3% DSS drinking water-induced UC mice. First of all, the physiological results showed that PPM60-III and SPPM60-III could alleviate UC, which was shown by the reduction in liver Treg cells, the rebalance of Th17/Treg, and the modulation of inflammatory cytokines. In addition, the 16S rRNA results showed that PPM60-III and SPPM60-III could decrease Beijerinck and Bifidobacterium, and increase Akkermansia, Escherichia coli, and Fidobacteria. Finally, the metabonomics results showed that PPM60-III and SPPM60-III also restored purine and glycerolipid metabolism, up-regulated nicotinate and nicotinamide metabolism and caffeine metabolism to inhibit inflammation. In conclusion, PPM60-III and SPPM60-III could inhibit UC by regulating gut bacteria composition and metabolite distribution; SPPM60-III showed better anti-colitis activity.

Protective effects and mechanisms of HuDiChangRong capsule on TNBS-induced ulcerative colitis in mice

Ethnopharmacological relevanceUC, characterized by chronic inflammation primarily affecting the colon and rectum, follows a protracted relapsing course marked by inflammation and an abundance of free radicals at the onset. Hudichangrong Capsule (HDCRC), a traditional Chinese medicinal formula, has long been employed in the treatment of UC and chronic bacillary dysentery, exhibiting positive therapeutic outcomes and a high rate of cure in clinical practice. Aim of the studyThe precise mechanism underlying its efficacy for UC remains elusive. Our objective was to investigate the anti-inflammatory effect and underlying mechanisms of HDCRC on TNBS-induced UC. Materials and methodsHere, we introduced HDCRC and induced UC using TNBS. SPF BALB/c mice were divided into 6 groups as follows: control group, colitis model group, colitis treated with sulfasalazine (400 mg/kg) group, and colitis treated with HDCRC (156, 312, and 624 mg/kg) groups. To assess the effects of HDCRC on colitis, we measured body weight loss, disease activity index (DAI), colon length, tissue damage, degree of inflammation, immune capacity, and oxidative stress. Additionally, we evaluated the TLR-4/MyD88 pathway and its downstream signaling using immunohistochemistry, real-time qPCR, and Western blot. Network pharmacology was used for main target prediction. 16s rRNA was employed for gut microbiota detechtion and UPLC-QTOF-MS was used for its and its metabonomics. ResultsHDCRC significantly slowed weight loss, ameliorated DAI, restored colon length, alleviated TNBS-induced tissue damage. It exerted the therapeutic effects via reducing oxidative stress, restoring immune balance, normalizing the inflammatory mediator levels and restoring intestinal barrier integrity. Furthermore, HDCRC mainly alleviate UC via suppressing the TLR-4/MyD88 pathway and its downstream signaling. The key components of the downstream pathway, including TLR-4, MyD88, NF-κB p65, ERK, p-JNK, p38, p-JAK1, JAK1, p-STAT3, and STAT3, were improved, thereby ameliorating the TNBS-induced injury. In addition, HDCRC could regulate gut microbiota (eg. Erysipelaloclostridium,etc.) and its metabonomics (eg. Vitamin B6 metabolism) in UC mice. ConclusionsIn conclusion, HDCRC exerts a protective effect against TNBS-induced UC in mice by inhibiting the TLR-4/MyD88 pathway and its downstream signaling, and partially JAK1/STAT3, suppressing oxidative stress, regulating immunity, restoring intestinal barrier integrity, and regulating gut microbiota and its metabonomics.

Evaluation of inhibitory potential of the flavonoid-rich fraction of Myrica esculenta Buch.-Ham. ex D. Don against DSS-induced colonic inflammation in mice

ObjectiveMyrica esculenta (family Myricaceae), a valuable plant species in China and India, has been traditionally used by many tribes and local communities to manage gut disorders. Scientific validation of its anti-ulcerative colitis activity was aimed. MethodsThe ethyl acetate fraction of Myrica esculenta (MeEa) was prepared and evaluated for its potency against DSS-induced ulcerative colitis (UC) in mice at 200 and 400 mg/kg BW oral dose. The effective dose of MeEa was determined through its effect on DSS-induced UC and was further analyzed through its effects on disease activity index (DAI), colon length, colon weight/length ratio, spleen weight, serum and colon tissue cytokine level, cell count and hemoglobin content. Further, the effect was determined through histopathology and FITC-dextran-induced membrane permeability assay. ResultsBetween the two doses, MeEa at 400 mg/kg BW was found to be the most effective dose in terms of reduced DAI scores, protected colon length from shortening, decreased colon weight/length ratio, reduced spleen weight, decreased pro-inflammatory cytokine level and stabilized the anti-inflammatory cytokine level in serum and colon tissue. MeEa 400 reduced cell counts and increased hemoglobin content and platelet count. MeEa 400 also prevented the colon by protecting epithelial cells and crypts. MeEa 400 provided significant protection from intestinal leakage and reduced FITC dextran level in serum. DiscussionMeEa 400 possesses significant anti-inflammatory potential and acts via attenuation of DSS-induced UC and inhibition of DAI scores. It reduces pro-inflammatory cytokines and stabilizes anti-inflammatory cytokine levels, reduces cell count, and protects epithelial tissue and crypts in the colon, as well as intestinal membrane leakage that occurred due to FITC-dextran administration in mice.

Pharmacodynamic and pharmacokinetic study of Shaoyao Gancao decoction for repairing intestinal barrier damage in ulcerative colitis

ObjectiveTo study the therapeutic effect and mechanism of Shaoyao Gancao Decoction (SGD) on ulcerative colitis (UC) mice based on the perspective of intestinal barrier, and this study provides a new consultation for the clinical application of SGD. MethodsThe chemical composition of SGD was characterized by HPLC. The UC mouse model was constructed by 3 % dextran sodium sulfate (DSS), which were randomly divided into the model group (DSS), the positive drug group (5-ASA), the Shaoyao group (SYD), Gancao group (GCD), and the Shaoyao Gancao Decoction group (SGD) at low, medium, and high dosages, respectively. The effects of each drug treatment group on UC were evaluated by the rate of body weight loss, disease activity index (DAI), colon length, spleen index, histopathological evaluations, and the levels of serum inflammatory factors (IL-1β, IL-6, IL-10, IL-21, and TNF-α). The goblet cell was observed by Alcian blue/periodic acid-Schiff (AB/PAS) straining, ELISA was used to detect the content of LPS in serum, and Western blot was used to detect the changes in the expression of tight junction proteins ZO-1, occludin, and the pathway proteins TLR4 and NF-κBp65 in the colonic tissues, to explore the protective effect of SGD on the intestinal barrier of UC mice. The vivo absorption process of the main active ingredients in the SG, SY and GC groups was determined by LC-MS. ResultsThe contents of albiflorin, paeoniflorin, liquiritin apioside, liquiritin and glycyrrhetinic acid were 6.1227 mg/g, 20.8993 mg/g, 4.0054 mg/g, 3.6140 mg/g and 8.2515 mg/g, respectively. Compared with DSS group, SGD reduced weight loss(P<0.01) and DAI scores(P<0.05), prevented colon shortening(P<0.01), and ameliorated histopathological damage of the colon in UC mice(P<0.01). SGD also protected the intestinal barrier to alleviate UC by significantly reducing serum LPS and inflammatory factor levels, altering the number of goblet cells, promoting tight junction proteins (ZO-1 and occludin) and decreasing the expression of TLR4 and NF-κB in colonic tissues. Pharmacokinetic results showed that there was no significant difference in Cmax, AUC0-t (μg/L.h) and Tmax of albiflorin and paeoniflorin between the SY and SG groups, the Tmax was within 1 h; the AUC0-t (μg/L.h) of liquiritin and glycyrrhizic acid were about 1.6 and 1.9 times higher in the SG group compared to the GC group, respectively. The Cmax, Tmax and AUC0-t (μg/L.h) of glycyrrhizinic acid were significantly reduced to 0.73, 0.68 and 0.68 times of that of the GC group. ConclusionSGD may have a therapeutic effect on DSS-induced UC mice by repairing the damaged intestinal barrier through the TLR4/NF-κB pathway. The combination of Shaoyao and Gancao increased the absorption of liquiritin and glycyrrhizic acid in vivo. The combination of Shaoyao and Gancao could promote the absorption of Gancao, and that the pairing of the two herbs could have a synergistic effect.

Optimization of a gelatin/carboxymethylcellulose-based probiotic microcapsule and its application in preventing dextran sodium sulfate-induced colitis in mice.

Oral administration of probiotics has demonstrated substantial potential in alleviating colitis. However, most of the ingested microorganisms struggle to survive the harsh conditions of the gastrointestinal tract, leading to decreased efficacy. In the present study, using double emulsification (W1/O/W2) and complex coacervation methods, we developed a gelatin/carboxymethyl cellulose (CMC)-based probiotic microcapsule and analyzed the efficacy of encapsulated probiotics in preventing dextran sodium sulfate (DSS)-induced colitis in mice. Our results reveal that nearly 90% of the encapsulated probiotics remained viable after 30-day storage at 4°C and approximately 38.1% of viable bacteria (4.0 × 108 cfu/g) survived after 4-h simulated gastrointestinal digestion. In a DSS-induced colitis model, pretreatment with probiotics exerted significant protective effects, with the bacterial microcapsule-treated group having superior outcomes to those of the bacterial suspension plus empty carrier group. Probiotic treatments, especially those administered in the encapsulated form, significantly increased fecal short-chain fatty acid contents, and altered the intestinal microbial composition. The family Muribaculaceae, dominant bacteria in the mouse gut, may be the key microorganism involved in the BM regulation process. Our study presents an alternative approach to treating colitis using probiotics. PRACTICAL APPLICATION: The encapsuled probiotic showed remarkable storage stability at 4°C, maintained good vitality after simulated digestion, and gained superior outcomes in preventing colitis. Our results offer an alternative approach for the probiotic preparations aiming to prevent the intestinal inflammation.

5-aminosalicylic acid alleviates colitis and protects intestinal barrier function by modulating gut microbiota in mice.

5-aminosalicylic acid (5-ASA) is widely used in the treatment of ulcerative colitis (UC), but its anti-inflammatory mechanism is complex and has not been fully understood. DSS model was used to test the effect of 5-ASA. Tight junction and Ki-67 were detected by western blot, immunofluorescence, and immunohistochemistry or qPCR. 16S rRNA gene sequencing of gut microbiota and subsequent bioinformatics and statistical analysis were performed to identify the specific bacteria which were associated with the treatment effect of 5-ASA. GC-MS was performed to test short-chain fatty acids (SCFAs). Antibiotic-treated mice were used to demonstrate the key role of endogenous gut microbiota. Here, we found that 5-ASA alleviated dextran sulfate sodium (DSS)-induced colitis in mice. Moreover, 5-ASA significantly repaired the intestinal barrier. At the molecular level, 5-ASA markedly raised the expression of tight junction proteins including JAM-A and occludin and cell proliferation marker Ki-67 in mice. In addition, bacterial 16S rRNA gene sequencing and bioinformatics analysis showed that 5-ASA significantly modulated the DSS-induced gut bacterial dysbiosis. In detail, it stimulated the growth of protective bacteria belonging to Faecalibaculum and Dubosiella, which were negatively correlated with colitis parameters, and blocked the expansion of pro-inflammatory bacteria such as Escherichia-Shigella and Oscillibacter, which were positively correlated with colitis in mice. Meanwhile, 5-ASA increased the cecal acetate level. Most notably, 5-ASA was no longer able to treat colitis and reverse gut barrier dysfunction in antibiotic-treated mice that lacked endogenous gut microbiota. Our data suggested that the anti-inflammatory activity of 5-ASA required the inherent intestinal flora, and the gut microbiota was a potential and effective target for the treatment of ulcerative colitis.

TIPE2 aggravates experimental colitis and disrupts intestinal epithelial barrier integrity by activating JAK2/STAT3/SOCS3 signal pathway

Ulcerative colitis (UC) is a chronic relapsing and progressive inflammatory disease of the colon. TIPE2 is a negative regulator of innate and adaptive immunity that maintains immune homeostasis. We found that TIPE2 was highly expressed in mucosa of mice with colitis. However, the role of TIPE2 in colitis remains unclear. We induced colitis in mice with dextran sulphate sodium (DSS) and treated them with TIPE2, and investigated the inflammatory activity of the colon in vivo by cytokines detection and histopathological analyses. We also measured inflammatory alteration and tight junctions induced by DSS in vitro. The results demonstrated that administration of TIPE2 promoted the severity of colitis in mice and human colon epithelial cells. Furthermore, TIPE2 aggravated intestinal epithelial barrier dysfunction by decreasing the expression of the tight junction proteins Occludin, Claudin-1 and ZO-1. In addition, TIPE2 exacerbated intestinal inflammatory response by inhibiting the expression of SOCS3, remarkably activating JAK2/STAT3 signaling pathway, and increasing the translocation of phosphorylated STAT3 into the nucleus. Silencing of Tipe2 attenuated the DSS-induced activation of JAK2/STAT3, thereby rescuing epithelial inflammatory injury and restoring barrier dysfunction. These results indicate that TIPE2 augments experimental colitis and disrupted the integrity of the intestinal epithelial barrier by activating the JAK2/STAT3/SOCS3 signaling pathway.

Huaiyu pill alleviates inflammatory bowel disease in mice blocking toll like receptor 4/ myeloid differentiation primary response gene 88/ nuclear factor kappa B subunit 1 pathway.

To investigate the therapeutic effects of Huaiyu pill (, HYP) on inflammatory bowel disease (IBD) and the underlying mechanisms have not been elucidated. To establish the IBD model, mice were administered with dextran sulfate sodium (DSS). Mice were intragastrically pre-treated with sulfasalazine (SASP) and HYP. Disease activity index (DAI) and colon length were monitored, and the colonic tissues were subjected to hematoxylin-eosin staining. Pro-inflammatory factors and vascular inflammation-related proteins were determined using enzyme-linked immunosorbent assay (ELISA). The potential mechanisms of HYP were examined using network pharmacology analysis.The expressions of zona occludens 1 (ZO-1), occludin, toll like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (MYD88), and nuclear factor kappa B p65 subunit (NF-κB p65) in colon tissues were examined using Western blotting or immunohistochemical analyses. Pre-treatment with HYP enhanced the colon length, decreased DAI scores, and mitigated histopathological alterations in DSS-treated mice. HYP alleviated intestinal inflammation by downregulating the levels of interleukin 1 beta (IL-1β), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α) and interleukin 17 (IL-17). Additionally, HYP suppressed the disruption of the gut barrier by upregulating the ZO-1, occludin, and mucin 2 (MUC2) levels and downregulating the endothelin 1 (ET-1) and erythropoietin (EPO) levels. Network pharmacological analysis and experimental results revealed that HYP downregulated the colonic tissue levels of TLR4, MYD88, and NF-κB p65 in DSS-treated mice. This study investigated the in vivotherapeutic effects of HYP on IBD and the underlying molecular mechanisms. These findings provide an experimental foundation for the clinical application of HYP.

Butyrolactone-I from marine fungi alleviates intestinal barrier damage caused by DSS through regulating Lactobacillus johnsonii and its metabolites in the intestine of mice

Butyrolactone-I (BTL-1), a secondary metabolite from the marine fungus Aspergillus terreus, exhibits numerous biological activities. Previous research has indicated that Butyrolactone-I alleviates intestinal epithelial inflammation via the TLR4/NF-κB and MAPK pathways. However, the mechanisms underlying its protection against intestinal barrier damage remain unclear. This study aims to further elucidate these mechanisms. We observed that BTL-1 administration increased the abundance of Lactobacillus johnsonii (LJ) in both in vivo and in vitro experiments, prompting an investigation into the effects of LJ and its metabolites on DSS-induced inflammatory bowel disease (IBD). The results demonstrated that BTL-1 significantly upregulated tight junction (TJ) and adherens junction (AJ) proteins, maintained intestinal barrier integrity, and alleviated DSS-induced IBD in mice. These effects were associated with the proliferation of LJ and its metabolites, such as butyric and propionic acids, and the inhibition of the MAPK signaling pathway in the colon. Interestingly, administering LJ alone produced a protective effect against DSS-induced IBD similar to that observed with BTL-1. Furthermore, butyric acid, a metabolite of LJ, also upregulated TJ/AJ proteins in intestinal epithelial cells through the MAPK signaling pathway. Our findings suggest that BTL-1 regulates intestinal flora, promotes LJ proliferation, protects intestinal barrier integrity, increases the concentrations of butyric and propionic acids, and ultimately inhibits the activation of the MAPK signaling pathway in mice to alleviate IBD. Therefore, BTL-1 could potentially be used as a natural drug to prevent IBD and maintain intestinal flora balance. ImportanceWe explored how butyrolactone-I exerts a preventive effect on IBD through intestinal bacteria (Lactobacillus johnsonii).