In recent years, there has emerged academic tendency towards the neurogenic mechanism of ulcerative colitis (UC). As one of the supports to the hypothesis of UC being a neurogenic inflammation, we have built a colitis model by intrathecal (ith) injection of a haptten 2,4-dinitrochlorobenzene (DNCB) to DNCB-sensitized rats. In order to explore further the neuroimmunal mechanism of this colitis model, we here focused on a pro-inflammatory cytokine, migration inhibitory factor (MIF), to observe its expression in rat colon nervous tissue and spinal cord in the colitis induced by ith injection of DNCB. At the same time we also observed the effect of MIF antibody pretreatment on the disease active index (DAI) score and the colon pathology by HE staining in the colitis rats. The results obtained showed that the immunofluorescence intensity of double staining of MIF protein in colon nervous tissue and spinal cord was increased in 0.8% and 1.6% DNCB-induced colitis groups than that in the control (60% ethanol) group. Both the colon pathology and the DAI score were significantly reduced by MIF antibody ith pretreatment. Ith injection of 0.8% DNCB after MIF antibody (1:10, 1:5) pretreatment could only induce lower DAI score (P<0.01 as compared, respectively, to the IgG pretreatment group). The colon pathological changes in ith 0.8% DNCB rats were mild, even little after MIF antibody (1:10, 1:5) pretreatment. These results suggest that MIF in spinal cord and enteric nervous system is possibly involved in the rat colitis induced by ith injection of DNCB, which reflects a neuroimmunal mechanism underlying this kind of colitis. MIF is possibly one of the important neurochemical factors in this experimental colitis, even in the UC.
Animals ; Antibodies ; pharmacology ; Colitis, Ulcerative ; chemically induced ; metabolism ; Haptens ; adverse effects ; Injections, Spinal ; Macrophage Migration-Inhibitory Factors ; metabolism ; Rats

OBJECTIVES: Liver disease is the most common extra-intestinal manifestation of ulcerative colitis (UC), but the underlying pathogenesis is still not clarified. It is well accepted that the occurrence of UC-related liver disease has close correlation with immune activation, intestinal bacterial liver translocation, inflammatory cytokine storm, and the disturbance of bile acid circulation. The occurrence of UC-related liver disease makes the therapy difficult, therefor study on the pathogenesis of UC-related liver injury is of great significance for its prevention and treatment. Glutathione (GSH) shows multiple physiological activities, such as free radical scavenging, detoxification metabolism and immune defense. The synthesis and the oxidation-reduction all contribute to GSH antioxidant function. It is reported that the deficiency in hepatic GSH antioxidant function participates in multiple liver diseases, but whether it participates in the pathogenesis of UC-related liver injury is still not clear. This study aims to investigate the feature and underlying mechanism of GSH synthesis and oxidation-reduction function during the development of UC, which will provide useful information for the pathogenesis study on UC-related liver injury. METHODS: UC model was induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS)-ethanol solution (5 mg/0.8 mL per rat, 50% ethanol) via intra-colonic administration in rats, and the samples of serum, liver, and colon tissue of rats were collected at the 3rd, 5th, and 7th days post TNBS. The severity degree of colitis was evaluated by measuring the disease activity index, colonic myeloperoxidase activity, and histopathological score, and the degree of liver injury was evaluated by histopathological score and the serum content of alanine aminotransferase. Spearman correlation analysis was also conducted between the degree of colonic lesions and index of hepatic histopathological score as well as serum aspartate aminotransferase level to clarify the correlation between liver injury and colitis. To evaluate the hepatic antioxidant function of GSH in UC rats, hepatic GSH content, enzyme activity of GSH peroxidase (GSH-Px), and GSH reductase (GR) were determined in rats at the 3rd, 5th, and 7th days post TNBS, and the protein expressions of glutamine cysteine ligase (GCL), GSH synthase, GSH-Px, and GR in the liver of UC rats were also examined by Western blotting. RESULTS: Compared with the control, the disease activity index, colonic myeloperoxidase activity, and histopathological score were all significantly increased at the 3rd, 5th, and 7th days post TNBS (all P<0.01), the serum aspartate aminotransferase level and hepatic histopathologic score were also obviously elevated at the 7th day post TNBS (all P<0.05). There was a significant positive correlation between the degree of liver injury and the severity of colonic lesions (P=0.000 1). Moreover, compared with the control, hepatic GSH content and the activity of GSH-Px and GR were all significantly decreased at the 3rd and 5th days post TNBS (P<0.05 or P<0.01), and the protein expressions of GCL, GSH-Px, and GR were all obviously down-regulated at the 3rd, 5th, and 7th days post TNBS (P<0.05 or P<0.01). CONCLUSIONS There is a significant positive correlation between the degree of liver injury and the severity of colonic lesions, and the occurrence of reduced hepatic GSH synthesis and decreased GSH reduction function is obviously earlier than that of the liver injury in UC rats. The reduced hepatic expression of enzymes that responsible for GSH synthesis and reduction may contribute to the deficiency of GSH synthesis and oxidation-reduction function, indicating that the deficiency in GSH antioxidant function may participate in the pathogenesis of UC related liver injury.
Animals ; Antioxidants ; Aspartate Aminotransferases ; Colitis/chemically induced* ; Colitis, Ulcerative/metabolism* ; Colon/pathology* ; Glutathione/biosynthesis* ; Liver/metabolism* ; Peroxidase/metabolism* ; Rats ; Trinitrobenzenesulfonic Acid

The histopathological features and the associated clinical findings of ulcerative colitis (UC) are due to persistent inflammatory response in the colon mucosa. Interventions that suppress this response benefit UC patients. We tested whether sodium arsenite (SA) benefits rats with dextran sulfate sodium (DSS)-colitis. The DSS-colitis was induced by 5% DSS in drinking water. SA (10 mg/kg; intraperitoneally) was given 8 h before DSS treatment and then every 48 h for 3 cycles of 7, 14 or 21 d. At the end of each cycle rats were sacrificed and colon sections processed for histological examination. DSS induced diarrhea, loose stools, hemoccult positive stools, gross bleeding, loss of body weight, loss of epithelium, crypt damage, depletion of goblet cells and infiltration of inflammatory cells. The severity of these changes increased in the order of Cycles 1, 2 and 3. Treatment of rats with SA significantly reduced this severity and improved the weight gain.
Animals ; Arsenites ; pharmacology ; Body Weight ; Colitis ; chemically induced ; drug therapy ; Colitis, Ulcerative ; chemically induced ; Colon ; pathology ; Dextran Sulfate ; pharmacology ; Epithelium ; pathology ; Inflammation ; Male ; Models, Biological ; Rats ; Rats, Wistar ; Sodium Compounds ; pharmacology ; Time Factors ; Treatment Outcome

AIMTo investigate the effects of glutamine on the colonic mucosa of mice subjected to colitis gravis.

METHODS64 Kunming mice were divided randomly into 4 groups (n=16): healthy group: animals not subjected to colitis; model group: animals subjected to colitis gravis but without glutamine supplementation; low-Gln group: animals subjected to colitis gravis and with low dose of glutamine supplementation; high-Gln group: animals subjected to colitis gravis and with high dose of glutamine supplementation. Animals belonging to the control, the low-Gln, the high-Gin groups were subjected to coloclysis by HAC to be colitis gravis animals. When the models were established, the healthy and the control groups were given some isotonic Na chloride by intragastric administration. The low-Gln group and the high-Gln group were given the same volume but different concentration of glutamine(low-Gln group--2 mmol x Kg(-1) bw, high-Gln group--2 mmol x Kg(-1) bw) for 7 days. Then the mice were sacrificed, the pathohistological changes of the colon were observed, besides, the content of endotoxin in the blood serum, the level of counteracting oxidation and the activities of MPO of the colon tissue were determined.

RESULTSThe glutamine lessened the pathological injures in the colon and relieved the step up of the content of endotoxin in the blood serum , the step down level of counteracting oxidation and the step up activity of MPO in the colon tissue, which were caused by colitis gravis.

CONCLUSIONThe glutamine can protect the colon of mice subjected to colitis gravis.

Acetic Acid ; Animals ; Colitis, Ulcerative ; chemically induced ; drug therapy ; pathology ; Colon ; pathology ; Female ; Glutamine ; pharmacology ; therapeutic use ; Male ; Mice ; Random Allocation

OBJECTIVETo prepare the diammonium glycyrrhizinate-loaded chitosan nanoparticles (DG-CS NPs), and evaluate its pharmaceutical properties and pharmacodynamic effects on ulcerative colitis (UC).

METHODDG-CS NPs were prepared by spray drying method and optimized by orthogonal design. The morphology, size and in vitro release of DG-CS NPs were investigated. The therapeutic effects of DG-CS NPs on UC mice induced by dextran sulfate were evaluated preliminarily through disease active index method.

RESULTThe size of DG-CS NPs with loading capacity about (51.25 +/- 1.75)% was in the range of 300-600 nm. The release of DG-CS NPs was associated with environmental pH value and displayed significant therapeutic and preventive effects on UC.

CONCLUSIONDG-CS NPs prepared by spray drying method showed efficacy on UC mice.

Animals ; Chitosan ; chemistry ; Colitis, Ulcerative ; chemically induced ; drug therapy ; Dextran Sulfate ; toxicity ; Disease Models, Animal ; Female ; Glycyrrhizic Acid ; chemistry ; therapeutic use ; Male ; Mice ; Nanoparticles ; chemistry

Several models of experimental ulcerative colitis have been reported previously. However, none of these models showed the optimum characteristics. Although dextran sulfate sodium-induced colitis results in inflammation resembling ulcerative colitis, an obvious obstacle is that dextran sulfate sodium is very expensive. The aim of this study was to develop an inexpensive model of colitis in rats. Sprague-Dawley rats were treated with 2% dextran sulfate sodium in drinking water for 3 d followed by an intracolonic administration of 30% ethanol. The administration of 2% dextran sulfate sodium followed by 30% ethanol induced significant weight loss, diarrhea and hematochezia in rats. Severe ulceration and inflammation of the distal part of rat colon were developed rapidly. Histological examination showed increased infiltration of polymorphonuclear leukocytes, lymphocytes and existence of cryptic abscesses and dysplasia. The model induced by dextran sulfate sodium at lower concentration followed by 30% ethanol is characterized by a clinical course, localization of the lesions and histopathological features similar to human ulcerative colitis and fulfills the criteria set out at the beginning of this study.
Acute Disease ; Administration, Rectal ; Animals ; Colitis, Ulcerative ; chemically induced ; pathology ; Dextran Sulfate ; administration & dosage ; Disease Models, Animal ; Drug Administration Schedule ; Ethanol ; administration & dosage ; Female ; Rats

OBJECTIVETo investigate the role of mast cells and gut hormones and their interactions in TNBS-induced ulcerative colitis.

METHODSRat models of ulcerative colitis were established by a single intracolonic injection of 100 mg/kg TNBS (in 0.3 ml 50% ethanol). At 0, 6, 11, 16, 21 days after TNBS injection, the rats were sacrificed to determine the count of the mast cells. Histamine level in the whole blood, and the levels of histamine, substance P (SP), vasoactive intestinal peptide (VIP), and somatostatin (SS) in the distal colons were measured by fluorimetry or radioimmune assay. Immunofluorescence double staining was used to observe the relationship of the mast cells with SP, VIP, and SS positive nerve fibers.

RESULTSOn day 6 after TNBS injection, obvious ulcers occurred in the distal colon of the rats with significantly increased histamine level in the whole blood (P<0.05) but significantly decreased colonic histamine levels (P<0.05). The histamine levels in the whole blood and distal colon gradually recovered the normal levels. The mast cells significantly increased on day 16 (P<0.05) and maintained the high level till day 21. The distribution of mast cells was altered after TNBS injection, and the cells were found to aggregate in the myenteric region. SP levels in the distal colon significantly increased on day 11 (P<0.05) and maintained the high level till day 21. Immunofluorescence double staining revealed numerous mast cells close to the SP- and VIP-positive nerve fibers at different time points after TNBS injection. VIP positivity and the number of VIP-positive nerve fibers in the myenteric region were markedly increased, but no mast cells were observed in association with SP- and VIP-positive nerve fibers. The distribution of MC was not found to associate with the SS-positive nerve fibers.

CONCLUSIONThe mast cells and histamine released by them, as well as parasecretion of SP and VIP, participate in tissue damage by TNBS-induced colitis. Bidirectional neuroimmunomodulation of the mast cells, SP and VIP have important effect on the development of TNBS-induced colitis.

Animals ; Colitis, Ulcerative ; chemically induced ; metabolism ; pathology ; Disease Models, Animal ; Male ; Mast Cells ; secretion ; Rats ; Rats, Sprague-Dawley ; Substance P ; metabolism ; Trinitrobenzenesulfonic Acid ; toxicity ; Vasoactive Intestinal Peptide ; 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*

Ulcerative colitis(UC) is a recurrent, intractable inflammatory bowel disease. Coptidis Rhizoma and Bovis Calculus, serving as heat-clearing and toxin-removing drugs, have long been used in the treatment of UC. Berberine(BBR) and ursodeoxycholic acid(UDCA), the main active components of Coptidis Rhizoma and Bovis Calculus, respectively, were employed to obtain UDCA-BBR supramolecular nanoparticles by stimulated co-decocting process for enhancing the therapeutic effect on UC. As revealed by the characterization of supramolecular nanoparticles by field emission scanning electron microscopy(FE-SEM) and dynamic light scattering(DLS), the supramolecular nanoparticles were tetrahedral nanoparticles with an average particle size of 180 nm. The molecular structure was described by ultraviolet spectroscopy, fluorescence spectroscopy, infrared spectroscopy, high-resolution mass spectrometry, and hydrogen-nuclear magnetic resonance(H-NMR) spectroscopy. The results showed that the formation of the supramolecular nano-particle was attributed to the mutual electrostatic attraction and hydrophobic interaction between BBR and UDCA. Additionally, supramolecular nanoparticles were also characterized by sustained release and pH sensitivity. The acute UC model was induced by dextran sulfate sodium(DSS) in mice. It was found that supramolecular nanoparticles could effectively improve body mass reduction and colon shortening in mice with UC(P<0.001) and decrease disease activity index(DAI)(P<0.01). There were statistically significant differences between the supramolecular nanoparticles group and the mechanical mixture group(P<0.001, P<0.05). Enzyme-linked immunosorbent assay(ELISA) was used to detect the serum levels of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6), and the results showed that supramolecular nanoparticles could reduce serum TNF-α and IL-6 levels(P<0.001) and exhibited an obvious difference with the mechanical mixture group(P<0.01, P<0.05). Flow cytometry indicated that supramolecular nanoparticles could reduce the recruitment of neutrophils in the lamina propria of the colon(P<0.05), which was significantly different from the mechanical mixture group(P<0.05). These findings suggested that as compared with the mechanical mixture, the supramolecular nanoparticles could effectively improve the symptoms of acute UC in mice. The study provides a new research idea for the poor absorption of small molecules and the unsatisfactory therapeutic effect of traditional Chinese medicine and lays a foundation for the research on the nano-drug delivery system of traditional Chinese medicine.
Animals ; Mice ; Colitis, Ulcerative/drug therapy* ; Ursodeoxycholic Acid/adverse effects* ; Berberine/pharmacology* ; Interleukin-6 ; Tumor Necrosis Factor-alpha/pharmacology* ; Drugs, Chinese Herbal/pharmacology* ; Colon ; Nanoparticles ; Dextran Sulfate/adverse effects* ; Disease Models, Animal ; Colitis/chemically induced*

Platycodon grandiflorus polysaccharide (PGP) is one of the main components of P. grandiflorus, but the mechanism of its anti-inflammatory effect has not been fully elucidated. The aim of this study was to evaluate the therapeutic effect of PGP on mice with dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) and explore the underlying mechanisms. The results showed that PGP treatment inhibited the weight loss of DSS-induced UC mice, increased colon length, and reduced DAI, spleen index, and pathological damage within the colon. PGP also reduced the levels of pro-inflammatory cytokines and inhibited the enhancement of oxidative stress and MPO activity. Meanwhile, PGP restored the levels of Th1, Th2, Th17, and Treg cell-related cytokines and transcription factors in the colon to regulate colonic immunity. Further studies revealed that PGP regulated the balance of colonic immune cells through mesenteric lymphatic circulation. Taken together, PGP exerts anti-inflammatory and anti-oxidant effect and regulates colonic immunity to attenuate DSS-induced UC through mesenteric lymphatic circulation.
Animals ; Mice ; Colitis, Ulcerative/drug therapy* ; Platycodon ; Colon/pathology* ; Cytokines ; Anti-Inflammatory Agents/therapeutic use* ; Polysaccharides/therapeutic use* ; Dextran Sulfate ; Disease Models, Animal ; Colitis/chemically induced* ; Mice, Inbred C57BL