The present study aimed to explore the effect of nuclear factor erythroid 2 related factor 2(Nrf2)/heme oxygenase-1(HO-1) signaling pathway in intestinal protection by Sishen Pills against ulcerative colitis(UC). After the UC model was induced by 3% dextran sodium sulfate(DSS), experimental animals were randomly divided into control group, model group, salazosulfapyridine(SASP) group, and low-and high-dose Sishen Pills groups. Drug intervention(ig) was performed for seven consecutive days during modeling. On the 7 th day, the mice were euthanized. The body weight and colon length were recorded, and the histopathological changes of the colon were observed by HE staining. Serum interleukin-6(IL-6), tumor necrosis factor-α(TNF-α), total antioxidant capacity(T-AOC), malondialdehyde(MDA), and reactive oxygen species(ROS) were detected by ELISA. The protein and mRNA expression of Nrf2, HO-1, and NADPH quinine oxidoreductase-1(NQO-1) was determined by Western blot and reverse transcription-polymerase chain reaction(RT-PCR). Compared with the normal group, the model group exhibited reduced body weight, colon length, and T-AOC, increased IL-6, TNF-α, MDA, and ROS, and diminished protein and mRNA expression of Nrf2, HO-1, and NQO-1 in the colon tissues. Compared with the model group, the SASP group and high-dose Sishen Pills group showed elevated body weight, colon length, and T-AOC, lowered IL-6, TNF-α, MDA, and ROS levels, and increased protein and mRNA expression of Nrf2, HO-1, and NQO-1 in the colon tissues. As assessed by HE staining, Sishen Pills could improve the pathological changes of the colon. The findings suggested that Sishen Pills could protect the colon against UC induced by 3% DSS. The specific mechanism of action may be related to the anti-inflammatory and anti-oxidative stress effects by the activation of the Nrf2/HO-1 signaling pathway.
Animals ; Colitis, Ulcerative/genetics* ; Dextran Sulfate ; Heme Oxygenase-1/metabolism* ; Mice ; NF-E2-Related Factor 2/metabolism* ; Signal Transduction

Humans ; Animals ; Mice ; NF-kappa B/metabolism* ; Crohn Disease/drug therapy* ; Dextran Sulfate ; Colitis/metabolism* ; Macrophages/metabolism* ; Adenosine Triphosphate/metabolism* ; Mice, Inbred C57BL ; Disease Models, Animal ; Colon/metabolism*

BACKGROUNDDisrupted Ca2+ homeostasis contributes to the development of colonic dysmotility in ulcerative colitis (UC), but the underlying mechanisms are unknown. This study aimed to examine the alteration of colonic smooth muscle (SM) Ca2+ signaling and Ca2+ handling proteins in a rat model of dextran sulfate sodium (DSS)-induced UC.

METHODSMale Sprague-Dawley rats were randomly divided into control (n = 18) and DSS (n = 17) groups. Acute colitis was induced by 5% DSS in the drinking water for 7 days. Contractility of colonic SM strips (controls, n = 8 and DSS, n = 7) was measured in an organ bath. Cytosolic resting Ca2+ levels (n = 3 in each group) and Ca2+ transients (n = 3 in each group) were measured in single colonic SM cells. Ca2+ handling protein expression was determined by Western blotting (n = 4 in each group). Differences between control and DSS groups were analyzed by a two-sample independent t-test.

RESULTSAverage tension and amplitude of spontaneous contractions of colonic muscle strips were significantly enhanced in DSS-treated rats compared with controls (1.25 ± 0.08 g vs. 0.96 ± 0.05 g, P= 0.007; and 2.67 ± 0.62 g vs. 0.52 ± 0.10 g, P= 0.013). Average tensions of carbachol-evoked contractions were much weaker in the DSS group (1.08 ± 0.10 g vs. 1.80 ± 0.19 g, P= 0.006). Spontaneous Ca2+ transients were observed in more SM cells from DSS-treated rats (15/30 cells) than from controls (5/36 cells). Peak caffeine-induced intracellular Ca2+ release was lower in SM cells of DSS-treated rats than controls (0.413 ± 0.046 vs. 0.548 ± 0.041, P= 0.033). Finally, several Ca2+ handling proteins in colonic SM were altered by DSS treatment, including sarcoplasmic reticulum calcium-transporting ATPase 2a downregulation and phospholamban and inositol 1,4,5-trisphosphate receptor 1 upregulation.

CONCLUSIONSImpaired intracellular Ca2+ signaling of colonic SM, caused by alteration of Ca2+ handing proteins, contribute to colonic dysmotility in DSS-induced UC.

Animals ; Colitis ; chemically induced ; metabolism ; Colon ; cytology ; metabolism ; Dextran Sulfate ; toxicity ; Male ; Muscle, Smooth ; metabolism ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; physiology

Ultra-high performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry(UHPLC-Q-TOF-MS) was employed in this study to observe the effect of Huaihua Powder on the serum metabolites of mice with ulcerative colitis and reveal the mechanism of Huaihua Powder in the treatment of ulcerative colitis. The mouse model of ulcerative colitis was established by dextran sodium sulfate salt(DSS). The therapeutic effect of Huaihua Powder on ulcerative colitis was preliminarily evaluated based on the disease activity index(DAI), colon appearance, colon tissue morphology, and the content of inflammatory cytokines such as tumor necrosis factor-α(TNF-α), interleukin-6(IL-6), and interleukin-1β(IL-1β). UHPLC-Q-TOF-MS was employed to profile the endogenous metabolites of serum samples in blank control group, model group, and low-, medium-, and high-dose Huaihua Powder groups. Multivariate analyses such as principal component analysis(PCA), partial least squares discriminant analysis(PLS-DA), and orthogonal partial least squares discriminant analysis(OPLS-DA) were performed for pattern recognition. Potential biomarkers were screened by Mass Profiler Professional(MPP) B.14.00 with the thresholds of fold change≥2 and P<0.05. The metabolic pathways were enriched by MetaboAnalyst 5.0. The results showed that Huaihua Powder significantly improved the general state and colon tissue morphology of mice with ulcerative colitis, reduced DAI, and lowered the levels of TNF-α, IL-6, and IL-1β in serum. A total of 38 potential biomarkers were predicted to be related to the regulatory effect of Huaihua Powder, which were mainly involved in glycerophospholipid metabolism, glycine, serine, and threonine metabolism, mutual transformation of glucuronic acid, and glutathione metabolism. This study employed metabolomics to analyze the mechanism of Huaihua Powder in the treatment of ulcerative colitis, laying a foundation for the further research.
Mice ; Animals ; Colitis, Ulcerative/metabolism* ; Powders ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-6/metabolism* ; Metabolomics ; Colon ; Disease Models, Animal ; Biomarkers ; Dextran Sulfate/therapeutic use*

The study is aimed to explore the molecular mechanism of the treatment of apocynin in dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mice. 5% DSS was used to mimic the UC model, and 2% apocynin was applied to treat the UC mice. HE staining was used for histopathological evaluation. Chemiluminescence technique was used to measure reactive oxygen species (ROS) production, and the rate of consumption of NADPH inhibited by DPI was detected to determine the NADPH oxidases (NOXs) activity. Western blot was applied to identify the level of p38MAPK phosphorylation, Griess reaction assay to analyze NO production, immunoenzymatic method to determine prostaglandin E2 (PGE2) production, real time RT-PCR and Western blot to identify the expression of iNOS and COX2, and enzyme linked immunosorbent assay to detect inflammatory cytokines TNF-α, IL-6, IFN-γ, IL-1β. Rat neutrophils were separated, and then ROS production, NOXs activity, NO and PGE2 production, NOX1 and p-p38MAPK expression were detected. Compared with the UC group, apocynin decreased ROS over-production and NOXs activity (P < 0.01), reduced p38MAPK phosphorylation, inhibited NO, PGE2 and cytokines production (P < 0.01). Apocynin also decreased NOXs activity and ROS over-production (P < 0.01), inhibited p38MAPK phosphorylation and NOX1 expression, and reduced NO and PGE2 production (P < 0.01) in separated neutrophils from UC mice. Therefore, apocynin could relieve inflammation in DSS-induced UC mice through inhibiting NOXs-ROS-p38MAPK signal pathway, and neutrophils play an important role.
Acetophenones ; pharmacology ; Animals ; Colitis, Ulcerative ; chemically induced ; drug therapy ; Cytokines ; metabolism ; Dextran Sulfate ; Inflammation ; drug therapy ; MAP Kinase Signaling System ; Mice ; NADH, NADPH Oxidoreductases ; metabolism ; Neutrophils ; metabolism ; Rats ; Reactive Oxygen Species ; metabolism ; p38 Mitogen-Activated Protein Kinases ; metabolism

This study aims to explore the effect of tryptanthrin on potential metabolic biomarkers in the serum of mice with ulcerative colitis(UC) induced by dextran sulfate sodium(DSS) based on liquid chromatography-mass spectrometry(LC-MS) and predict the related metabolic pathways. C57BL/6 mice were randomly assigned into a tryptanthrin group, a sulfasalazine group, a control group, and a model group. The mouse model of UC was established by free drinking of 3% DSS solution for 11 days, and corresponding drugs were adminsitrated at the same time. The signs of mice were observed and the disease activity index(DAI) score was recorded from the first day. Colon tissue samples were collected after the experiment and observed by hematoxylin-eosin(HE) staining. The levels of interleukin-4(IL-4), interleukin-10(IL-10), tumor necrosis factor-α(TNF-α), interleukin-6(IL-6), and interleukin-8(IL-8) in the serum were measured by enzyme linked immunosorbent assay(ELISA). The serum samples were collected from 6 mice in each group for widely targeted metabolomics. The metabolic pathways were enriched by MetaboAnalyst 5.0. The results showed that compared with the model group, tryptanthrin treatment decreased the DAI score(P<0.05), alleviated the injury of the colon tissue and the infiltration of inflammatory cells, lowered the levels of proinflammatory cytokines, and elevated the levels of anti-inflammatory cytokines in the serum. The metabolomic analysis revealed 28 differential metabolites which were involved in 3 metabolic pathways including purine metabolism, arachidonic acid metabolism, and tryptophan metabolism. Tryptanthrin may restore the metabolism of the mice with UC induced by DSS to the normal level by regulating the purine metabolism, arachidonic acid metabolism, and tryptophan metabolism. This study employed metabolomics to analyze the mechanism of tryptanthrin in the treatment of UC, providing an experimental basis for the utilization and development of tryptanthrin.
Mice ; Animals ; Colitis, Ulcerative/drug therapy* ; Tryptophan ; Arachidonic Acid/metabolism* ; Mice, Inbred C57BL ; Colon ; Cytokines/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-6/metabolism* ; Metabolomics ; Purines/therapeutic use* ; Dextran Sulfate/metabolism* ; Disease Models, Animal ; Colitis/chemically induced*

OBJECTIVETo investigate the changes in the activity of nuclear factor-kappaB (NF-kappa B) in mice with dextran sulphate sodium (DSS)-induced rat colitis and its modulalorg effect on intercellular adhesion molecule-1 (ICAM-1) expression.

METHODSTwenty normal male mice were randomized into DSS group and normal saline (NS) control group according to a matched-pair design. From days 1 to 7, the mice in DSS group were subjected to oral administration of 5%DSS solution, and from days 8 to 20, NS was given instead, for a total of 3 cycles. In the control group, only NS was administered. The colonic pathology was observed using HE staining and the mucosa 1 damage was scored for each mouse. The DNA-binding activity of NF-kappa B was tested by electrophoretic mobility shift assay, and the expressions of ICAM-1 and NF-kappa B p65 were detected using immunohistochemistry.

RESULTSThe DNA-binding activity of NF-kappa B was significantly increased in DSS group as compared with NS group. ICAM-1 and p65 expressions were detected in the nuclei of the vascular endothelial and inflammatory cells, especially in the mucosa and submucosa, but such positive cells were seldom observed in NS group. A positive correlation was found between the DNA-binding activity of NF-kappa B and ICAM-1 expression.

CONCLUSIONNF-kappa B activation is an important event in the development of DSS-induced colitis in that activated NF-kappa B upregulates ICAM-1 expression during colonic inflammation.

Animals ; Colitis ; chemically induced ; metabolism ; DNA ; metabolism ; Dextran Sulfate ; Electrophoretic Mobility Shift Assay ; Immunohistochemistry ; Intercellular Adhesion Molecule-1 ; biosynthesis ; Male ; Mice ; Mice, Inbred BALB C ; NF-kappa B ; metabolism ; Protein Binding ; Random Allocation ; Transcription Factor RelA ; metabolism

BACKGROUNDDiarrhea is a common clinical feature of ulcerative colitis resulting from unbalanced intestinal fluid and salt absorption and secretion. The Cl(-)/HCO3(-) exchanger SLC26A3 is strongly expressed in the mid-distal colon and plays an essential role in colonic Cl(-) absorption and HCO3(-) secretion. Slc26a3 expression is up-regulated by lysophosphatidic acid (LPA) in vitro. Our study was designed to investigate the effects of LPA on SLC26A3 expression and the diarrheal phenotype in a mouse colitis model.

METHODSColitis was induced in C57BL/6 mice by adding 4% of dextran sodium sulfate (DSS) to the drinking water. The mice were assigned to LPA treatment DSS group, phosphate-buffered saline (PBS) treatment DSS group, DSS only group and untreated mice with a completely randomized design. Diarrhea severity was evaluated by measuring mice weight, disease activity index (DAI), stool water content and macroscopic evaluation of colonic damage. The effect of LPA treatment on Slc26a3 mRNA level and protein expression in the different groups of mice was investigated by quantitative PCR and Western blotting.

RESULTSAll mice treated with DSS lost weight, but the onset and severity of weight loss was attenuated in the LPA treatment DSS group. The increases in stool water content and the macroscopic inflammation score in LPA treatment DSS group were significantly lower compared to DSS control group or PBS treatment DSS group ((18.89±8.67)% vs. (28.97±6.95)% or (29.48±6.71)%, P = 0.049, P = 0.041, respectively and 2.67±0.81 vs. 4.5±0.83 or 4.5±0.54, P = 0.020, P = 0.006, respectively), as well as the increase in DAI (P = 0.004, P = 0.008, respectively). LPA enema resulted in higher Slc26a3 mRNA and protein expression levels compared to PBS-treated and untreated DSS colitis mice.

CONCLUSIONLPA increases Slc26a3 expression in the inflamed intestine and reduces diarrhea severity in DSS-induced colitis, suggesting LPA might be a therapeutic strategy in the treatment of colitis associated diarrhea.

Animals ; Antiporters ; genetics ; metabolism ; Colitis ; chemically induced ; drug therapy ; Colon ; immunology ; metabolism ; Dextran Sulfate ; pharmacology ; Dextrans ; pharmacology ; Diarrhea ; drug therapy ; metabolism ; Female ; Immunoblotting ; Intestines ; drug effects ; metabolism ; Lysophospholipids ; therapeutic use ; Mice ; Mice, Inbred C57BL

BACKGROUND/AIMS: This animal study aimed to define the underlying cellular mechanisms of intestinal barrier dysfunction. METHODS: Rats were fed 4% with dextran sodium sulfate (DSS) to induce experimental colitis. We analyzed the sugars in 24-hour urine output by high pressure liquid chromatography. The expression of claudins, mannan-binding lectin (MBL), and MBL-associated serine proteases 2 (MASP-2) were detected in the colonic mucosa by immunohistochemistry; and apoptotic cells in the colonic epithelium were detected by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling method assay. RESULTS: The lactulose and sucralose excretion levels in the urine of rats with DSS-induced colitis were significantly higher than those in the control rats. Mannitol excretion was lower and lactulose/mannitol ratios and sucralose/mannitol ratios were significantly increased compared with those in the control group (p<0.05). Compared with the controls, the expression of sealing claudins (claudin 3, claudin 5, and claudin 8) was significantly decreased, but that of claudin 1 was increased. The expression of pore-forming claudin 2 was upregulated and claudin 7 was downregulated in DSS-induced colitis. The epithelial apoptotic ratio was 2.8%+/-1.2% in controls and was significantly increased to 7.2%+/-1.2% in DSS-induced colitis. The expression of MBL and MASP-2 in the intestinal mucosa showed intense staining in controls, whereas there was weak staining in the rats with colitis. CONCLUSIONS: There was increased intestinal permeability in DSS-induced colitis. Changes in the expression and distribution of claudins, increased epithelial apoptosis, and the MASP-2-induced immune response impaired the intestinal epithelium and contributed to high intestinal permeability.
Animals ; Apoptosis/*physiology ; Claudins/*metabolism ; Colitis/chemically induced/immunology/*physiopathology ; Colon/immunology/physiopathology ; Dextran Sulfate ; Intestinal Mucosa/*physiopathology ; Lactulose/metabolism ; Mannitol/metabolism ; Mannose-Binding Lectin/*immunology ; Permeability ; Rats ; Rats, Sprague-Dawley ; Sucrose/analogs & derivatives/metabolism ; Up-Regulation

Ulcerative colitis (UC) is a chronic and recurrent inflammatory bowel disease (IBD) that has become a major gastroenterologic problem during recent decades. Numerous complicating factors are involved in UC development such as oxidative stress, inflammation, and microbiota disorder. These factors exacerbate damage to the intestinal mucosal barrier. Spirulina platensis is a commercial alga with various biological activity that is widely used as a functional ingredient in food and beverage products. However, there have been few studies on the treatment of UC using S. platensis aqueous extracts (SP), and the underlying mechanism of action of SP against UC has not yet been elucidated. Herein, we aimed to investigate the modulatory effect of SP on microbiota disorders in UC mice and clarify the underlying mechanisms by which SP alleviates damage to the intestinal mucosal barrier. Dextran sulfate sodium (DSS) was used to establish a normal human colonic epithelial cell (NCM460) injury model and UC animal model. The mitochondrial membrane potential assay 3-‍‍(4,5-dimethylthiazol-2-yl)-2,‍5-diphenyltetrazolium bromide (MTT) and staining with Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) and Hoechst 33258 were carried out to determine the effects of SP on the NCM460 cell injury model. Moreover, hematoxylin and eosin (H&E) staining, transmission electron microscopy (TEM), enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qPCR), western blot, and 16S ribosomal DNA (rDNA) sequencing were used to explore the effects and underlying mechanisms of action of SP on UC in C57BL/6 mice. In vitro studies showed that SP alleviated DSS-induced NCM460 cell injury. SP also significantly reduced the excessive generation of intracellular reactive oxygen species (ROS) and prevented mitochondrial membrane potential reduction after DSS challenge. In vivo studies indicated that SP administration could alleviate the severity of DSS-induced colonic mucosal damage compared with the control group. Inhibition of inflammation and oxidative stress was associated with increases in the activity of antioxidant enzymes and the expression of tight junction proteins (TJs) post-SP treatment. SP improved gut microbiota disorder mainly by increasing antioxidant enzyme activity and the expression of TJs in the colon. Our findings demonstrate that the protective effect of SP against UC is based on its inhibition of pro-inflammatory cytokine overproduction, inhibition of DSS-induced ROS production, and enhanced expression of antioxidant enzymes and TJs in the colonic mucosal barrier.
Animals ; Antioxidants/pharmacology* ; Colitis/prevention & control* ; Colitis, Ulcerative/metabolism* ; Colon/metabolism* ; Dextran Sulfate/toxicity* ; Disease Models, Animal ; Gastrointestinal Microbiome ; Inflammation/metabolism* ; Mice ; Mice, Inbred C57BL ; Oxidative Stress ; Reactive Oxygen Species/metabolism* ; Spirulina