Mouse Model Of Colitis Research Articles

Berberine and magnolol exert cooperative effects on ulcerative colitis in mice by self-assembling into carrier-free nanostructures

The risk of ulcerative colitis (UC) is increasing worldwide with limited success using classical drugs, which has underscored the development of novel agents. Recently, carrier-free molecular assembly has been proven to be an effective drug delivery system, but it has yet to be examined for UC drug development using phytochemicals. Based on traditional Chinese medicine compatibility and potential medicinal uses, a pair of natural compounds, berberine (BBR) and magnolol (MAG), were found to self-assemble into nanostructures in aqueous solutions. Spectral analysis revealed that the assembly mechanisms of BBR and MAG were mediated through charge interactions and π-π stacking. Pharmacokinetic studies and animal imaging showed that BBR-MAG self-assembly (BM) effectively promoted the oral bioavailability and biodistribution of BBR in the colon. BM exhibited superior effects in regulating inflammatory factors, maintaining colon barrier integrity, and regulating gut microbiota in a dextran sulfate sodium salt-induced colitis mouse model. Additionally, no apparent signs of toxicity were observed, suggesting that BM has a favorable safety profile. This study presents a new strategy for UC management and highlights the cooperative effects of combined phytochemicals.Graphical

PARP1 inactivation increases regulatory T / Th17 cell proportion in intestinal inflammation. Role of HMGB1

Inflammatory bowel diseases (IBD) are chronic relapsing disorders with increasing prevalence. Knowledge gaps still limit the possibility to develop more specific and effective therapies. Using a dextran sodium sulfate colitis mouse model, we found that inflammation increased the total number and altered the frequencies of leukocytes within colon mesenteric lymph nodes (cMLNs). Although the inflammation reduced the frequency of regulatory T (Treg) cells, their absolute numbers were increased. Increased frequency of colitogenic Th17 cells was also observed. Noteworthy, untreated mice lacking Poly(ADP-ribose)-Polimerase-1 functional gene (PARP-1KO) displayed higher frequency of Treg cells and lower percentage of Th17 cells in cMLNs. In colitic PARP-1KO mice the inflammation driven expansion of the Foxp3 Treg population was more pronounced than in WT mice. Conversely, colitis increased Th17 cells to a lower extent in PARP-1KO mice compared with WT mice, resulting in a more protective Treg/Th17 cell ratio. Consequently PARP-1KO mice developed less severe colitis with reduced expression of inflammatory cytokines. In ex vivo experiments PARP-1KO and WT CD11c dendritic cells (DCs) promoted naïve CD4 T cell differentiation differently, the former sustaining more efficiently the generation of Treg cells, the latter that of Th17 cells. Addition of HMGB1 B box or of dipotassium glycyrrhizate, which sequesters extracellular HMGB1, revealed a role for this alarmin in the regulation exerted by PARP-1 on the stimulating vs. tolerogenic function of DCs during colitis. Moreover, a higher percentage of CD11c DC from PARP-1KO mice expressed CD103, a marker associated with the ability of DC to induce Treg cells, compared with WT DC. Conversely, PARP-1KO DC were including a reduced percentage of CX3CR1+ DC, described to induce Th17 cells. These findings were observed in both splenic and colon lamina propria DC.

Dysregulated myeloid differentiation in colitis is induced by inflammatory osteoclasts in a TNFα-dependent manner

Inflammatory bowel disease (IBD) is characterized by very severe intestinal inflammation associated with extra-intestinal manifestations. One of the most critical ones is bone destruction, which remains a major cause of morbidity and a risk factor for osteopenia and osteoporosis in IBD patients. In various mouse models of IBD, we and other have demonstrated concomitant bone loss due to a significant increase in osteoclast activity. Besides bone resorption, osteoclasts are known to control hematopoietic niches in vivo and modulate inflammatory responses in vitro, suggesting they may participate in chronic inflammation in vivo. Here, using different models of colitis, we showed that osteoclast inhibition significantly reduced disease severity and that induction of osteoclast differentiation by RANKL contributed to disease worsening. Our results demonstrate a direct link between osteoclast activity and myeloid cell accumulation in the intestine during colitis. RNAseq analysis of osteoclasts from colitic mice revealed overexpression of genes involved in the remodeling of hematopoietic stem cell niches. We also demonstrated that osteoclasts induced hematopoietic progenitor proliferation accompanied by a myeloid skewing in the early phases of colitis, which was confirmed in a model of RANKL-induced osteoclastogenesis. Mechanistically, inhibition of TNF-α reduced the induction of myeloid skewing by OCL both in vitro and in vivo. Lastly, we observed that osteoclastic activity and the proportion of myeloid cells in the blood are positively correlated in patients with Crohn’s disease. Collectively, our results shed light on a new role of osteoclasts in colitis in vivo, demonstrating they exert their colitogenic activity through an early action on hematopoiesis, leading to an increase in myelopoiesis sustaining gut inflammation.

Lactobacillus johnsonii colonizing in mice intestine contributes to control the gut barrier function via regeneration of the crypt in DSS‐treated mice

AbstractBackgroundUnbalanced gut microbiota is considered to cause dysfunction of the gut barrier function. Lactobacillus johnsonii MG, isolated from mouse feces as gut associating lactobacilli, enhanced gut barrier function in Caco‐2 cells via interaction with JAM‐2 in tight junctions. In this study, the anti‐inflammatory effects of L. johnsonii MG were investigated in a colitis mouse model developed by treating mice with 3% dextran sulfate sodium (DSS) for 9 days.ResultsMG treatment of colitis mice resulted in fast recovery of the body weight and showed significant improvement in the disease activity index and histopathological scores. The histomorphological score increased by DSS treatment was significantly improved in the MG‐treated group. In the intestine, the expression of Ocln, Zo1, Itga6, Lama3, and Jam2 genes, which are involved in tight junction functions, were significantly upregulated in MG‐treated colitis mice. In the microflora analysis, the abundance of Ruminococcaceae, Bacteroides, and Lachnospiraceae were reduced in DSS‐treated mice and recovered by MG treatment.ConclusionWe reported the potential of L. johnsonii MG in the regeneration of crypts and integrity of matrix proteins in the gut of mice with colitis through its association with tight junctions. The experimental results provide new insights into the probiotic effect of tight junction associating L. johnsonii MG.

Curcumin-mediated photodynamic disinfection strategy with specific spectral range for mucoid Pseudomonas Aeruginosa from hospital water

BackgroundHospital water systems represent critical environments for the transmission of pathogens, including multidrug-resistant strains like mucoid Pseudomonas aeruginosa (M-PA). Conventional disinfection methods often struggle to eradicate these pathogens effectively, highlighting the need for innovative approaches. ObjectiveThis study aimed to develop an enhanced photodynamic disinfection strategy targeting M-PA from hospital water systems, using curcumin-mediated photodynamic inactivation (PDI) with specific spectral range. MethodsAn M-PA strain isolated from hospital water was subjected to photodynamic treatment using curcumin as the photosensitizer. The efficacy of different wavelengths of light and varying concentrations of curcumin, with and without Tris-EDTA adjuvants, was evaluated through bacterial enumeration, ROS level measurements, transcriptome analysis, and assessment of virulence factors and biofilm formation. In vivo experiments utilizing a DSS-induced colitis mouse model assessed the protective effects of the photodynamic treatment against M-PA infection. ResultsOur findings demonstrated that the combination of curcumin-mediated PDI with specific spectral range effectively reduced M-PA counts in water, particularly when supplemented with Tris-EDTA. Transcriptome analysis revealed significant downregulation of virulence-related genes under sublethal photodynamic conditions. Furthermore, photodynamic treatment inhibited pyocyanin production and biofilm formation in M-PA, highlighting its potential to disrupt pathogenicity mechanisms. In vivo experiments showed that PDI attenuated M-PA-induced colitis in mice, indicating its protective efficacy. ConclusionThis study presents a promising photodynamic disinfection strategy for combating M-PA from hospital water. By optimizing curcumin-mediated PDI with specific spectral range and adjuvants, our approach demonstrates substantial efficacy in reducing bacterial counts, inhibiting virulence factors, and preventing M-PA-associated colitis.

FGF20 modulates gut microbiota to mitigate dextran sodium sulfate-induced ulcerative colitis in mouse models

Ulcerative colitis (UC), a prevalent form of inflammatory bowel disease (IBD), presents a significant clinical challenge due to the lack of optimal therapeutic strategies. Emerging evidence suggests that fibroblast growth factor 20 (FGF20) may play a crucial role in mitigating UC symptoms, though the mechanistic underpinnings remain elusive. In this study, a mouse model of UC was established using dextran sodium sulfate (DSS) to investigate the potential role of FGF20. Our findings revealed a marked reduction in FGF20 expression in the serum and colonic tissues of DSS-treated mice. Furthermore, FGF20 knockout did not exacerbate colonic damage in these mice. Conversely, overexpression of FGF20 via adeno-associated virus (AAV) significantly alleviated UC-associated symptoms. This alleviation was evidenced by attenuated intestinal shortening, mitigated weight loss, increased colonic goblet cell density and crypt formation, reduced inflammation severity and inflammatory cell infiltration, and enhanced expression of tight junction and mucin proteins. Moreover, FGF20 significantly ameliorated the dysbiosis of gut microbiota in DSS-treated mice by increasing the abundance of beneficial bacteria and decreasing the abundance of harmful bacteria. The beneficial effects of FGF20 were notably attenuated following gut microbiota depletion with an antibiotic regimen. Fecal microbiota transplantation experiments further supported the critical role of gut microbiota in mediating the effects of FGF20 on DSS-treated mice. In conclusion, these findings highlight the potential involvement of gut microbiota in the therapeutic effects of FGF20 in UC.

Bioorthogonal conjugation and responsive nanocoating of probiotics for inflammatory bowel disease

Inflammatory bowel disease (IBD) is closely associated with dysregulated immune response, gut mucosal barrier, and microbiota. Conventional treatments suffer from inferior bioavailability and inadequate efficiency. Herein, we present a synergistic therapeutic strategy based on multifunctionalized probiotics to mitigate IBD through single oral administration. The probiotic (Escherichia coli Nissle 1917) is bioorthogonally conjugated with immunomodulators and subsequently encapsulated by an enteric coating. The viability and bioactivity of probiotics are not affected by the modifications. And the armored probiotics are able to resist the harsh environment of the stomach and shed their enteric coating in the intestinal tract, exposing immunomodulators to polarize pro-inflammatory M1-type macrophages into anti-inflammatory M2-type. In a mouse colitis model, orally administered multifunctionalized probiotics cooperatively alleviate IBD with increased body weight to 1.13 folds and decreased disease activity index to 0.43 folds, through downregulating the pro-inflammatory cytokines expression, upregulating the epithelial tight junction-associated proteins levels to restore the intestinal barrier, and increasing the microbiota richness and abundance. This work exhibits a feasible approach to construct functionalized orally administered probiotics for enhanced synergistic therapy of IBD.

Gut bacterial type III secretion systems aggravate colitis in mice and serve as biomarkers of Crohn’s disease

Mesenteric adipose tissue (mAT) hyperplasia, known as creeping fat, is a pathologic characteristic of Crohn's disease (CD). In our previously reported cohort, we observed that Achromobacter pulmonis was the most abundant and prevalent bacteria cultivated from creeping fat. A whole genomic sequencing and identification of T3SS orthologs of mAT-derived A. pulmonis were used. A functional type III secretion system (T3SS) mediated the pathogenic potential of A. pulmonis invitro and in mouse colitis model. Furthermore, a T3SS Finder pipeline was introduced to evaluate gut bacterial T3SS orthologs in the feces of CD patients, ulcerative colitis and colorectal cancer patients. Here, we reveal that mAT-derived A. pulmonis possesses a functional T3SS, aggravates colitis in mice via T3SS, and exhibits T3SS-dependent cytotoxicity via a caspase-independent mechanism in macrophages and epithelial cells, which demonstrated the pathogenic potential of the T3SS-harboring A. pulmonis. Metagenomic analyses demonstrate an increased abundance of Achromobacter in the fecal of Crohn's disease patients compared to healthy controls. A comprehensive comparison of total microbial vT3SS abundance in various intestine diseases demonstrated that the specific enrichment of vT3SS genes was shown in fecal samples of CD, neither ulcerative colitis nor colorectal cancer patients, and ten T3SS gene-based biomarkers for CD were discovered and validated in a newly recruited CD cohort. Furthermore, treatment with exclusive enteral nutrition (EEN), an intervention that improves CD patient symptomatology, was found associated with a significant reduction in the prevalence of T3SS genes in fecal samples. These findings highlight the pathogenic significance of T3SSs in the context of CD and identify specific T3SS genes that could potentially function as biomarkers for diagnosing and monitoring the clinical status of CD patients. This work is supported by the National Key Research and Development Program of China (2020YFA0907800), the China Postdoctoral Science Foundation (2023M744089), the National Natural Science Foundation of China (32000096), the Shenzhen Science and Technology Programs (KQTD20200820145822023, RCIC20231211085944057, and ZDSYS20220606100803007), National Key Clinical Discipline, Guangdong Provincial Clinical Research Center for Digestive Diseases (2020B1111170004), Qingfeng Scientific Research Fund of the China Crohn's & Colitis Foundation (CCCF) (CCCF-QF-2022B71-1), and the Sixth Affiliated Hospital, Sun Yat-sen University Clinical Research 1010 Program 1010CG(2023)-08. These funding provided well support for this research work, which involved data collection, analysis, interpretation, patient recruitment and so on.

Untargeted Metabolomics Analysis of Lactic Acid Bacteria Fermented Acanthopanax senticosus with Regard to Regulated Gut Microbiota in Mice.

Previous studies have shown that Acanthopanax senticosus (AS) has a beneficial preventive and therapeutic effect on colitis. The fermentation of lactic acid bacteria (LAB) can alter the efficacy of AS by modifying or producing new compounds with potential bioactive properties. However, the specific components and mechanisms that enhance the efficacy are still unclear. In the present experiment, untargeted metabolomics was used to analyze the changes in active components before and after LAB fermentation of AS. The aim was to explain the mechanism of AS fermentation in treating colitis using a colitis model in mice. The results indicated that the fermentation of LAB could enhance the levels of total flavonoids and total polyphenols in FAS. Additionally, the beneficial components such as Delphinidin chloride, Diosmetin, Psoralidin, and Catechol significantly increased (p < 0.05). The colitis treatment experiment demonstrated that fermented AS could alleviate symptoms and improve the morphology of colitis in mice by enhancing antioxidant enzymes like CAT, T-SOD, and T-AOC. It also regulated the composition and abundance of intestinal flora species, such as Lactobacillus and Pseudogracilibacillus. The effectiveness of fermented AS was significantly superior to that of unfermented AS (p < 0.05). In conclusion, this study contributes to the application of lactic acid bacteria in AS fermentation and reveals the mechanism of fermentation AS for colitis.

Carthamin yellow alleviates dextran sodium sulfate-induced ulcerative colitis by repairing the intestinal barrier and activating the Nrf2/GPX4 axis

Ulcerative colitis (UC) is a chronic and recurrent inflammatory bowel disease (IBD). There is a growing prevalence of UC, but current conventional drugs lack efficacy. Carthamin yellow (CY) is a flavonoid compound extracted from safflower that is widely used and has various pharmacological effects. In the present study, we established colitis models in mice via DSS and in Caco-2 cells via lipopolysaccharide (LPS). Our results showed that CY treatment attenuated the symptoms of colitis by decreasing colonic pathological damage and improving disease activity index (DAI) scores. Notably, we observed that CY treatment decreased the levels of proinflammatory cytokines (TNF-α, IL-6, and IL-1β) by inhibiting the NLRP3/Caspase-1/IL-1β and MAPK/NF-κB signaling pathways. Moreover, we verified that treatment with CY obviously improved intestinal barrier function in both DSS-induced mice and LPS-stimulated Caco-2 cells. Ferroptosis-related markers were assessed. CY attenuated DSS-induced colitis by inhibiting ferroptosis, as assessed by Fe2+ accumulation, total antioxidant capacity (T-AOC), and reactive oxygen species (ROS), 4-hydroxynonenal (4-HNE), and glutathione (GSH) levels. Additionally, there was an increase in superoxide dismutase (SOD) and catalase (CAT) activity, as well as alterations in ferroptosis-related protein and gene expression (ACSL4, GPX4, SLC7A11, TfR1, and FTH1). Further analyses revealed that CY could inhibit ferroptosis via the Nrf2/GPX4 axis in both in vivo and RSL3-induced Caco-2 cell models. Importantly, the antiferroptotic and protective effects of CY were nullified by Nrf2 knockout in vivo and by the use of ML385 in vitro. In conclusion, the effects of CY on UC are strongly associated with the Nrf2 pathway. CY might be a potential candidate for the treatment of UC. Therefore, our results provide an important reference for investigating the mechanisms of flavonoid compounds involved in preventing inflammatory diseases.

Structural elucidation of a capsular polysaccharide from Bacteroides uniformis and its ameliorative impact on DSS-induced colitis in mice

Capsular polysaccharides derived from Bacteroides species have emerged as potential mitigators of intestinal inflammation in murine models. However, research on capsular polysaccharides from B. uniformis, a Bacteroides species with reduced abundance in colons of patients with ulcerative colitis, remains scarce. In this study, we extracted a neutral polysaccharide component from B. uniformis ATCC8492, termed BUCPS1B, using ultrasonic disruption, ethanol precipitation, and anion exchange chromatography. Structural characterization revealed BUCPS1B as a water-soluble polysaccharide with an α-1,4-glucan main chain adorned with minor substituent sugar residues. BUCPS1B alleviated intestinal inflammation in a mouse model of colitis and induced polarization of macrophages into M2-type. Furthermore, BUCPS1B modulated the gut microbiota composition, increased the abundance of the probiotic Akkermansia muciniphila and altered the gut metabolic profile to promote phenylalanine and short chain fatty acids metabolism. BUCPS1B is therefore a promising candidate to prevent inflammation and augment intestinal health.

Effects and Mechanisms of the Xianhecao-Huanglian Drug Pair on Autophagy-Mediated Intervention in Acute Inflammatory Bowel Disease via the JAK2/STAT3 Pathway

To explore the effects and mechanisms of the Xianhecao-Huanglian drug pair on autophagy-mediated intervention in acute inflammatory bowel disease (IBD) via the JAK2/STAT3 pathway. The study examined the underlying mechanisms of action of Xianhecao (APL) and Huanglian (CR) using a mouse model of dextran sodium sulfate (DSS)-induced acute inflammatory bowel disease (IBD) and in an in vitro model of IBD induced by lipopolysaccharide (LPS). The assessment of the therapeutic efficacy of the Xianhecao-Huanglian drug combination in a mouse model of IBD caused by DSS included the following parameters: Assessment of weight loss or gain. Measurement of the disease activity index (DAI). Assessment of histological damage. Determination of organ index. Measurement of colon length. Ascertain the levels of inflammatory cytokines in the intestinal tissues and serum of mice. Immunohistochemistry (IHC) for the measurement of tight junction protein concentrations in the colon mucosa, including ZO-1, claudin-1, and occludin. Measurement of mucin levels, specifically Mucin 2 (Muc2). Hematoxylin and eosin (HE) staining for the observation of histopathological alterations in colonic tissues. Examining the effect on goblet cells using periodic acid-Schiff (PAS) labeling. Application of Western blot and immunofluorescence techniques for the detection of autophagy-related markers in colonic tissues and proteins associated with the JAK2/STAT3 pathway. A cell inflammation model of IBD was induced through LPS stimulation, and a serum containing the Xianhecao-Huanglian drug pair (referred to as ACHP-DS) was formulated. Cell viability, anti-proinflammatory cytokines, tight junction proteins, mucins, autophagy-related markers, and the JAK2/STAT3 signaling pathway were assessed. The Xianhecao-Huanglian drug pair significantly ameliorated the symptoms and survival quality of acute IBD mice, reducing the disease activity index score, raising MUC2 secretion and tight junction protein expression to improve the integrity of the intestinal barrier, and preserving goblet cell function; thus, protecting the intestines. It effectively restrained triggering the signaling pathway that involves JAK2 and STAT3, leading to the suppression of inflammation and amelioration of colonic inflammation damage. Additionally, it induced autophagy in mouse colonic tissues.The in vitro experiments demonstrated that the Xianhecao-Huanglian drug combination enhanced the viability of LOVO and NCM460 cells when exposed to LPS stimulation. Furthermore, it suppressed the production of inflammatory cytokines such as IL-6, IL-1β, as well as TNF-α, whilst increasing the production of IL-10, ZO-1, along with MUC2. These effects collectively led to the alleviation of inflammation and the restoration of mucosal integrity. The results were consistent with what was shown in the in vivo trial. Moreover, the medication demonstrated effectiveness in reducing JAK2 along with STAT3 phosphorylation levels in the LPS-induced inflammatory model of IBD cells. The intervention with either the Xianhecao-Huanglian drug combination-containing serum or the JAK2/STAT3 pathway inhibitor AG490 reversed the pro-inflammatory effects and increased autophagy levels in the LPS-stimulated cells. The Xianhecao-Huanglian drug combination modulates the JAK2/STAT3 pathway, leading to the induction of autophagy, which serves as an intervention for IBD.

Protopanaxadiol derivative: A plant origin of novel selective glucocorticoid receptor modulator with anti-inflammatory effect

Constant efforts have been made to move towards maintaining the positive anti-inflammatory functions of glucocorticoids (GCs) while minimizing side effects. The anti-inflammatory effect of GCs is mainly attributed to the inhibition of major inflammatory pathways such as NF-κB through GR transrepression, while its side effects are mainly mediated by transactivation. Here, we investigated the selective glucocorticoid receptor modulator (SGRM)-like properties of a plant-derived compound. In this study, glucocorticoid receptor (GR)-mediated alleviation of inflammation by SP-8 was investigated by a combination of in vitro, in silico, and in vivo approaches. Molecular docking and cellular thermal shift assay suggested that SP-8 bound stably to the active site of GR via hydrogen bonding and hydrophobic interactions. SP-8 activated GR, induced GR nuclear translocation, and inhibited NF-κB pathway activation. Furthermore, SP-8 did not up-regulate the gene and protein expression of PEPCK and TAT in HepG2 cells, and it did not induce fat deposition like GC and has little effect on bone metabolism. Interestingly, SP-8 upregulated GR protein expression and did not cause GR phosphorylation at Ser211 in RAW264.7 cells. This work proved that SP-8 dissociated characteristics of transrepression and transactivation can be separated. In addition, the in vitro and in vivo anti-inflammatory effects of SP-8 were confirmed in LPS-induced RAW 264.7 cells and in a mouse model of DSS-induced ulcerative colitis, respectively. In conclusion, SP-8 might serve as a potential SGRM and might hold great potential for therapeutic use in inflammatory diseases.

The Immunosuppressive Properties of Cyclo-[D-Pro-Pro-β3-HoPhe-Phe-] Tetrapeptide Selected from Stereochemical Variants of Cyclo-[Pro-Pro-β3-HoPhe-Phe-] Peptide.

The anti-inflammatory, antiviral, and anti-cancer properties, as well as the mechanism of action of cyclo-[Pro-Pro-β3-HoPhe-Phe-] tetrapeptide (denoted as 4B8M), were recently described. The aim of this work was to synthesize and evaluate the immunosuppressive actions of the stereochemical variants of 4B8M by sequential substitution of L-amino acids by D-amino acids (a series of peptides denoted as P01-P07) using parent 4B8M as a reference compound. In addition, diverse available bioinformatics tools using machine learning and artificial intelligence were tested to find the bio-pharmacokinetic and polypharmacological attributes of analyzed stereomers. All peptides were non-toxic to human peripheral blood mononuclear cells (PBMCs) and only cyclo-[D-Pro-Pro-β3-HoPhe-Phe-] peptide (P03) was capable of inhibiting mitogen-induced PBMC proliferation. The peptides inhibited the lipopolysaccharide (LPS)-induced production of tumor necrosis factor-alpha (TNF-α) to various degrees, with P04 (cyclo-[Pro-Pro-D-β3-HoPhe-Phe-]) and P03 being the most potent. For further in vivo studies, P03 was selected because it had the combined properties of inhibiting cell proliferation and TNF-α production. P03 demonstrated a comparable ability to 4B8M in the inhibition of auricle edema and lymph node cell number and in the normalization of a distorted blood cell composition in contact sensitivity to the oxazolone mouse model. In the mouse model of carrageenan-induced inflammation of the air pouch, P03 exhibited a similar inhibition of the cell number in the air pouches as 4B8M, but its inhibitory effects on the percentage of neutrophils and eosinophils in the air pouches and blood, as well as on mastocyte degranulation in the air pouches, were stronger in comparison to 4B8M. Lastly, in a mouse model of dextran sulfate-induced colitis, similar effects to 4B8M regarding thymocyte number restoration and normalization of the blood cell pictures by P03 were observed. In summary, depending on either experimental findings or in silico predictions, P03 demonstrated comparable, or even better, anti-inflammatory and bio-pharmacokinetic properties to 4B8M and may be considered as a potential therapeutic. The possibility of P00 and P03 identification by circular dichroism measurements was tested by quantum-chemical calculations.

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.

An in situ bioadhesive foam as a large intestinal delivery platform for antibody fragment to treat inflammatory bowel disease

Biologics have been widely used as injectables in the treatment of inflammatory bowel disease (IBD). Different local treatment attempts have been developed in recent years. However, maintaining systemic levels of biologics is still crucial for achieving colitis remission. An equilibrium between systemic and local concentrations of biologics is therefore essential for treatment of colitis. Current formulations struggle to create optimal balance between drug concentrations in plasma and the colonic wall. Addressing this challenge, we developed a rectally delivered in situ foam that generates CO2via a reaction between potassium bicarbonate (PB) and citric acid (CA) without the aid of an external device. An anti-TNF-α antibody fragment (Fab) was loaded into the foam formulation, which promoted prolonged colon retention and improved Fab distribution up to proximal colon following rectal administration to mice. In addition, we observed increased plasma Fab concentrations in mice receiving the rectal Fab foam compared to a Fab solution. In a non-everted rat gut ex vivo model, a single exposure to the CO2-containing foam improved macromolecule transepithelial flux across colonic tissue by over ten-fold. Foam efficacy for Fab was investigated in a range of colitis mouse models, from acute to chronic. This non-invasive formulation platform demonstrates potential to overcome existing limitations in delivering biologics to inflamed colonic tissue.

ETS1 deficiency in macrophages suppresses colorectal cancer progression by reducing the F4/80+TIM4+ macrophage population.

Tumor-associated macrophages (TAMs) take on pivotal and complex roles in the tumor microenvironment (TME); however, their heterogeneity in the TME remains incompletely understood. ETS proto-oncogene 1 (ETS1) is a transcription factor that is mainly expressed in lymphocytes. However, its expression and immunoregulatory role in colorectal cancer (CRC)-associated macrophages remain unclear. In the study, the expression levels of ETS1 in CD68+ macrophages in the CRC microenvironment were significantly higher than those in matched paracarcinoma tissues. Importantly, ETS1 increased the levels of chemokines C-C motif chemokine ligand 2 (CCL2) and C-X-C motif chemokine ligand 10 (CXCL10) in lipopolysaccharide-stimulated THP-1 cells. It also boosted the migration and invasion of CRC cells during the in vitro co-culture. In the ETS1 conditional knockout mouse model, ETS1 deficiency in macrophages ameliorated the histological changes in DSS-induced ulcerative colitis mouse models and prolonged the survival in an azomethane/dextran sodium sulfate (AOM/DSS)-induced CRC model. ETS1 deficiency in macrophages substantially inhibited tumor formation, reduced F4/80+TIM4+ macrophages in the mesenteric lymph nodes, and decreased CCL2 and CXCL10 protein levels in tumor tissues. Moreover, ETS1 deficiency in macrophages effectively prevented liver metastasis of CRC and reduced the infiltration of TAMs into the metastasis sites. Subsequent studies have indicated that ETS1 upregulated the expression of T-cell immunoglobulin mucin receptor 4 in macrophages through the signal transducer and activator of the transcription 1 signaling pathway activated by the autocrine action of CCL2/CXCL10. Collectively, ETS1 deficiency in macrophages potentiates antitumor immune responses by repressing CCL2 and CXCL10 expression, shedding light on potential therapeutic strategies for CRC.

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.

Protective and therapeutic effects of hesperidin in an experimental colitis model

Ulcerative colitis is a gastrointestinal problem with increasing prevalence. In this study, the effect of hesperidin (commonly found in citrus white peel) on colitis was investigated. For this purpose, 28 Wistar albino female rats, 3–4 months old and weighing between 250–350 g, were used in the study. Rats were randomly divided into four groups: control (n=7), colitis (n=7), protective effect (n=7), and treatment (n=7) groups. Colitis was induced in rats with acetic acid (except control), and hesperidin was then administered at 150 mg/kg for 1 week before and after colitis. At the end of the study, IFN-γ and IL-6 values in blood, TAS, TOS, and OSI in tissue were evaluated. Intestinal tissues were assessed visually by haematoxylin and eosin staining. Our results showed that the levels of IFN-γ and IL-6 were highest in the colitis group and lowest in the treatment group, with statistical significance. The most histopathological damage was seen in the colitis group, while less prevalent in the treatment and control groups. The results of the study show that hesperidin had limited protective and therapeutic effects on experimental colitis mouse models.

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.