Differences in the effects and action modes of gut commensals against dextran sulfate sodium-induced intestinal inflammation

Inflammatory bowel disease(IBD)is a complex relapsing inflammatory disease in the gut and is driven by complicated host-gut microbiome interactions.Gut commensals have shown different functions in IBD prevention and treatment.To gain a mechanistic understanding of how different commensals affect intestinal inflammation,we compared the protective effects of 6 probiotics(belonging to the genera Akkermansia,Bifidobacterium,Clostridium,and Enterococcus)on dextran sulfate sodium(DSS)-induced colitis in mice with or without gut microbiota.Anti-inflammatory properties(ratio of interleukin(IL)-10 and IL-12)of these strains were also evaluated in an in vitro mesenteric lymph nodes(MLN)co-culture system.Results showed that 4 probiotics(belonging to the species Bifidobacterium breve,Bifidobacterium bifidum,and Enterococcus faecalis)can alleviate colitis in normal mice.The probiotic strains differed in regulating the intestinal microbiota,cytokines(IL-10,IL-1βand interferon(IFN)-γ),and tight junction function(Zonulin-1 and Occludin).By constrast,Akkermansia muciniphila AH39 and Clostridium butyricum FHuNHHMY49T1 were not protective.Interestingly,B.breve JSNJJNM2 with high anti-inflammatory potential in the MLN model could relieve colitis symptoms in antibiotic cocktail(Abx)-treated mice.Meanwhile,E.faecalis FJSWX25M1induced low levels of cytokines in vitro and showed no beneficial effects.Therefore,we provided insight into the clinical application of probiotics in IBD treatment.

Alkaline sphingomyelinase deficiency impairs intestinal mucosal barrier integrity and reduces antioxidant capacity in dextran sulfate sodium-induced colitis

BACKGROUND Ulcerative colitis is a chronic inflammatory disease of the colon with an unknown etiology.Alkaline sphingomyelinase(alk-SMase)is specifically expressed by intestinal epithelial cells,and has been reported to play an anti-inflammatory role.However,the underlying mechanism is still unclear.AIM To explore the mechanism of alk-SMase anti-inflammatory effects on intestinal barrier function and oxidative stress in dextran sulfate sodium(DSS)-induced colitis.METHODS Mice were administered 3%DSS drinking water,and disease activity index was determined to evaluate the status of colitis.Intestinal permeability was evaluated by gavage administration of fluorescein isothiocyanate dextran,and bacterial translocation was evaluated by measuring serum lipopolysaccharide.Intestinal epithelial cell ultrastructure was observed by electron microscopy.Western blotting and quantitative real-time reverse transcription-polymerase chain reaction were used to detect the expression of intestinal barrier proteins and mRNA,respectively.Serum oxidant and antioxidant marker levels were analyzed using commercial kits to assess oxidative stress levels.RESULTS Compared to wild-type(WT)mice,inflammation and intestinal permeability in alk-SMase knockout(KO)mice were more severe beginning 4 d after DSS induction.The mRNA and protein levels of intestinal barrier proteins,including zonula occludens-1,occludin,claudin-3,claudin-5,claudin-8,mucin 2,and secretory immunoglobulin A,were significantly reduced on 4 d after DSS treatment.Ultrastructural observations revealed progressive damage to the tight junctions of intestinal epithelial cells.Furthermore,by day 4,mitochondria appeared swollen and degenerated.Additionally,compared to WT mice,serum malondialdehyde levels in KO mice were higher,and the antioxidant capacity was significantly lower.The expression of the transcription factor nuclear factor erythroid 2-related factor 2(Nrf2)in the colonic mucosal tissue of KO mice was significantly decreased after DSS treatment.mRNA levels of Nrf2-regulated downstream antioxidant enzymes were also decreased.Finally,colitis in KO mice could be effectively relieved by the injection of tertiary butylhydroquinone,which is an Nrf2 activator.CONCLUSION Alk-SMase regulates the stability of the intestinal mucosal barrier and enhances antioxidant activity through the Nrf2 signaling pathway.

Effect of Berberine Chloride on Experimental Murine Colitis Induced by Dextran Sulfate Sodium

Aim To investigate the effect in berberine chloride （BER） on experimental ulcerative colitis in mice. Methods BALB/C mice in 6 groups were allowed to drink either 4% dextran sulfate sodium （DSS） solution or distilled water freely with different doses of BER （15 mg·kg^-1, 45 mg·kg^-1, 150 mg·kg^-1） or sallcylazosulfapyridine （SASP, 520 mg·kg^-1）, and solvent （0. 2 mL/10 mg Wt） once a day for 7 d, respectively. The symptom of ulcerative colitis was evaluated by disease activity index （DAI）. Myeloperoxidase （MPO） and superoxide dismutase （SOD） activities and malondialdehyde （MDA） content were determined by HE staining and immunohistochemistry of expressions of NF-κB p65 and intercellular adhesion molecule 1 （ ICAM-1 ） proteins to observe the damage to colon tissues and possible mechanisms. Results DAI, MPO activity, MDA content and expressions of ICAM-1 and NF-κB p65 were markedly increased, while SOD activity decreased in DSS-treated mice. Treatment of mice with different doses of BER or SASP significantly decreased DAI, MPO activity and MDA content, improved histological changes of colon tissues, blunted the expressions of NF-κB p65 and ICAM-1 proteins, and enhanced SOD activity. Conclusion Berberine chloride has excellent therapeutic effect on ulcerative colitis caused by DSS in mice. The possible mechanism may be related to its antioxidant and anti-inflammatory activities associated with inhibiting the NF-κB activation and ICAM-1 expression.

Resveratrol alleviates intestinal mucosal barrier dysfunction in dextran sulfate sodium-induced colitis mice by enhancing autophagy

BACKGROUND Intestinal mucosal barrier dysfunction plays an important role in the pathogenesis of ulcerative colitis(UC).Recent studies have revealed that impaired autophagy is associated with intestinal mucosal dysfunction in the mucosa of colitis mice.Resveratrol exerts anti-inflammatory functions by regulating autophagy.AIM To investigate the effect and mechanism of resveratrol on protecting the integrity of the intestinal mucosal barrier and anti-inflammation in dextran sulfate sodium(DSS)-induced ulcerative colitis mice.METHODS Male C57BL/6 mice were divided into four groups:negative control group,DSS model group,DSS+resveratrol group,and DSS+5-aminosalicylic acid group.The severity of colitis was assessed by the disease activity index,serum inflammatory cytokines were detected by enzyme-linked immunosorbent assay.Colon tissues were stained with haematoxylin and eosin,and mucosal damage was evaluated by mean histological score.The expression of occludin and ZO-1 in colon tissue was evaluated using immunohistochemical analysis.In addition,the expression of autophagy-related genes was determined using reverse transcription-polymerase chain reaction and Western-blot,and morphology of autophagy was observed by transmission electron microscopy.RESULTS The resveratrol treatment group showed a 1.72-fold decrease in disease activity index scores and 1.42,3.81,and 1.65-fold decrease in the production of the inflammatory cytokine tumor necrosis factor-α,interleukin-6 and interleukin-1β,respectively,in DSS-induced colitis mice compared with DSS group(P<0.05).The expressions of the tight junction proteins occludin and ZO-1 in DSS model group were decreased,and were increased in resveratrol-treated colitis group.Resveratrol also increased the levels of LC3B(by 1.39-fold compared with DSS group)and Beclin-1(by 1.49-fold compared with DSS group)(P<0.05),as well as the number of autophagosomes,which implies that the resveratrol may alleviate intestinal mucosal barrier dysfunction in DSS-induced UC mice by enhancing autophagy.CONCLUSION Resveratrol treatment decreased the expression of inflammatory factors,increased the expression of tight junction proteins and alleviated UC intestinal mucosal barrier dysfunction;this effect may be achieved by enhancing autophagy in intestinal epithelial cells.

Therapeutic effect of a hydroxynaphthoquinone fraction on dextran sulfate sodium-induced ulcerative colitis

AIM: To evaluate the therapeutic effect of hydroxynaphthoquinone mixture (HM) on dextran sulfate sodium (DSS)-induced colitis and explore the underlying mechanisms.

Involvement of lymphocytes in dextran sulfate sodium-induced experimental colitis

AIM： To investigate the roles of lymphocytes in the development of dextran sulfate sodium-induced colitis. METHODS： Using various doses of dextran sulfate sodium （DSS）, we induced colitis in wild-type B6 control and Rag-1 knockout （H-2b haplotype） mice, and evaluated the colitis in terms of symptomatic and histologic parameters, such as weight loss, survival, severity of diarrhea, shortage of colon length and histological changes. Symptomatic parameters were checked daily and histological changes were scored. RESULTS： Although development of colitis in Rag-1 knockout mice treated with high dose （5%） of DSS was comparable to that in B6 control mice, colitis progression was much more tolerable in Rag-1 knockout mice compared to than in B6 mice treated with low dose （1.5%） DSS. Symptomatic parameters as well as histopathologic changes were improved in Rag-1 knockout mice. CONCLUSION： These results indicate that the presence of lymphoo/tes contributes to colitis progression at low dose of DSS stimulation. Lymphoo/tes may play roles as an aggravating factor in DSS-induced colitis.

Protective effect of decursin and decursinol angelate-rich Angelica gigas Nakai extract on dextran sulfate sodium-induced murine ulcerative colitis

Objective: To investigate the anti-inflammatory effects of decursin and decursinol angelate-rich Angelica gigas Nakai(AGNE) on dextran sulfate sodium(DSS)-induced murine ulcerative colitis(UC).Methods: The therapeutic effect of an AGNE was analyzed in a mouse model of UC induced by DSS. Disease activity index values were measured by clinical signs such as a weight loss, stool consistency, rectal bleeding and colon length. A histological analysis was performed using hematoxylin and eosin staining. Key inflammatory cytokines and mediators including IL-6, TNF-a, PGE2, COX-2 and HIF-1 a were assayed by enzymelinked immunosorbent assay or western blotting.Results: Treatment with the AGNE at 10, 20, and 40 mg/kg alleviated weight loss,decreased disease activity index scores, and reduced colon shortening in mice with DSSinduced UC. AGNE inhibited the production of IL-6 and TNF-a in serum and colon tissue. Moreover, AGNE suppressed the increased expression of COX-2 and HIF-1 a and the increased production of PGE2 in colon tissue were observed in mice with DSSinduced UC. Additionally, histological damage was also alleviated by AGNE treatment.Conclusions: The findings of this study verified that AGNE significantly improves clinical symptoms and reduces the activity of various inflammatory mediators. These results indicate the AGNE has the therapeutic potential in mice with DSS-induced UC.

Induction of experimental acute ulcerative colitis in rats by administration of dextran sulfate sodium at low concentration followed by intracolonic administration of 30% ethanol

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 ulcera-tive colitis, an obvious obstacle is that dextran sulfate sodium is very expensive. The aim of this study was to develop an inex-pensive model of colitis in rats. Sprague-Dawley rats were treated with 2% dextran sulfate sodium in drinking water for 3 d fol-lowed 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 concentra-tion 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.

Sodium arsenite reduces severity of dextran sulfate sodium-induced ulcerative colitis in rats

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.

Sodium selenite ameliorates dextran sulfate sodiuminduced chronic colitis in mice by decreasing Th1, Th17, and γδT and increasing CD4(+)CD25(+) regulatory T-cell responses

AIM To assess the effect of sodium selenite on the severity of dextran sulfate sodium(DSS)-induced colitis in C57BL/6 mice.METHODS Mice were randomly divided into four groups(n = 10/group): normal group, selenium(Se) group, chronic colitis group, and Se + chronic colitis group. The mice were sacrificed on day 26. Survival rates, clinical symptoms, colon length, and histological changes were determined. The percentages and absolute numbers of immune system cells in the lamina propria lymphocytes(LPL) of the colon, the expression of m RNA in colon tissue, and the concentrations of Th1, Th17, and Treg cytokines in LPL from the large intestine, were measured.RESULTS Se significantly ameliorated the symptoms of colitis and histological injury(P < 0.05 each), increasing the proportions of neutrophils and CD4+ CD25+ T cells(P < 0.05 each) and decreasing the proportions of γδT cells, CD4+, CD4+CD44+, and CD4+ CD69+ T cells in LPL(P < 0.05 each). Moreover, Se reduced the expression of IL-6, IFN-γ, IL-17 A, IL-21, T-bet, and RORγt(P < 0.05 each), but enhanced the expression of IL-10 and Foxp3(P < 0.05 each). CONCLUSION These results suggest that Se protects against DSSinduced chronic colitis perhaps by increasing the number of CD4(+)CD25(+) Tregs that suppress the secretion of proinflammatory cytokines and populations of Th1, Th17, and γδT cells.

Longitudinal analysis of inflammation and microbiota dynamics in a model of mild chronic dextran sulfate sodium-induced colitis in mice

AIM: To characterize longitudinally the inflammation and the gut microbiota dynamics in a mouse model of dextran sulfate sodium (DSS)-induced colitis.

Antibody to eosinophil cationic protein suppresses dextran sulfate sodium-induced colitis in rats

AIM： To produce an antibody against rat eosinophil cationic protein （ECP） and to examine the effects of the antibody in rats with dextran sulfate sodium （DSS）-induced colitis. METHODS： An antibody was raised against rat ECP. Rats were treated with 3% DSS in drinking water for 7 d and received the antibody or normal serum. The colons were examined histologically and correlated with clinical symptoms. Immunohistochemistry and Western blot analysis were estimated as a grade of inflammation. RESULTS： The ECP antibody stained the activated eosinophils around the injured crypts in the colonic mucosa. Antibody treatment reduced the severity of colonic ulceration and acute clinical symptoms （diarrhea and/or bloodstained stool）. Body weight gain was significantly greater and the colon length was significantly longer in anti-ECPtreated rats than in normal serum-treated rats. Expression of ECP in activated eosinophils was associated with the presence of erosions and inflammation. The number of Ki-67-positive cells in the regenerated surface epithelium increased in anti-ECP-treated rats compared with normal serum-treated rats. Western blot analysis revealed reduced expression of macrophage migration inhibitory factor （MIF） in anti-ECP-treated rats. CONCLUSION： Our results indicate that treatment with ECP antibody, improved DSS-induced colitis in rats, possibly by increasing the regenerative activity of the colonic epithelium and downregulation of the immune response, and suggest that anti-ECP may promote intestinal wound healing in patients with ulcerative colitis （UC）.

Capillary Zone Electrophoresis Investigation of Interactions between Granulocyte-colony Stimulating Factor and Dextran Sulfate/Carrageenan Oligosaccharide

The interactions between granulocyte-colony stimulating factor (G-CSF) and dextran sulfate / κ-carrageenan oligosaccharide were studied by capillary zone electrophoresis. Dextran sulfate could strongly interact with G-CSF and the complex was detected. The binding constant and stoichiometry were determined to be 1.2×106 (mol/L)-1 and 3:1, respectively. However, the interaction between κ-carrageenan oligosaccharide and G-CSF was not found.

Differential analysis of intestinal microbiota and metabolites in mice with dextran sulfate sodium-induced colitis

BACKGROUND Intestinal micro-ecological imbalances impair the intestinal barrier and induce intestinal inflammation,for example,ulcerative colitis(UC).According to the latest research,abnormalities in intestinal microbiota structure and their metabolites play a dominant role in UC progression;in addition,they could affect the mucus barrier based on different factors.Although numerous studies have confirmed the important role of intestinal microbiota in UC pathogenesis,the intricate connection between microbiota and metabolites and mucus barrier in UC occurrence remains unclear,and correlation analyses of differential microbiota and their metabolites under UC are relatively scarce.AIM To reveal the differential intestinal microbiota and metabolites in UC pathogenesis and explore more sensitive biomarker compositions.METHODS We used the antibiotic combination method to establish intestinal pseudo-aseptic mice;afterward,dextran sulfate sodium(DSS)was applied to establish an acute experimental colitis mice model.Colitis severity,assessed based on disease activity index,colorectal length,colorectal wet weight,and histological lesions,and mucus-related staining(mucopolysaccharide alcian blue and immunofluorescence of mucin),was compared between the pseudo-aseptic and bacterial colitis mice.Finally,differential intestinal microbiota,metabolites,and their association and correlations,were analyzed by 16s rDNA sequencing in combination with non-targeted metabolomics,through gas chromatography-mass spectrometry.RESULTS Compared with the pseudo-aseptic mice,intestinal bacteria positive mice were more severely ill and their intestinal mucus loss was more pronounced in DSS-induced colitis(P<0.05),suggesting that different microbiota and metabolites could cause the different degrees of colitis.Subsequently,we observed that in addition to Klebsiella,and Bacteroides,which were widely associated with colitis,Candidatus Stoquefichus,Anaerobiospirillum,Muribaculum,and Negativibacillus may be involved in protection against colitis.Furthermore,differential metabolites of the microbiota were mainly enriched in the synthesis-related pathways of key structural sequences of mucin.In combination with the mucin-related staining and immunofluorescence results,the findings indicate that the differential microbiota and their metabolites potentially regulate the composition and function of mucus under colitis.CONCLUSION Microbiota and their metabolites are major factors regulating the composition and function of mucus,in turn influencing the function and structure of intestinal mucus barrier under colitis.The different microbiota and metabolites identified in the present study could be novel biomarkers for colitis.

Dramatic Changes of Matrix Metalloproteinases-7 and Lysozyme in the Ulcerative Colitis of Mice Induced by Dextran Sulfate Sodium

Ulcerative colitis （UC） is a lifelong illness with profound emotional and social impacts, and could cause serious damage to large intestine, especially in colon. However, the pathogenesis of UC remained unclear. The present study attempts to find out the role of matrix metalloproteinases-7 （MMP-7） and lysozyme in the pathogenesis of UC through a mice model induced by dextran sulfate sodium （DSS）. The UC model was evaluated both by disease activity index （DAI） and the intestinal histopathology. The results show that there is a high correlation between the DAI score and the pathological changes of colon. Interleukin-6 （IL-6） serum levels and large intestinal fluids levels in UC mice are always higher than that of the control groups, which might be associated with the degree of the inflammation damage in the colon. The change tendency of the MMP-7 mRNA and protein expressions are both up-regulated firstly and then down-regulated from 1 to 5 d in the colon, but only the MMP-7 protein is up-regulated at 7 d again. The up-regulated MMP-7 levels in the early stage of UC may play a protective role through the activated defensins, while the down-regulated levels in the mid-later stage of UC may be connected with the severe lesions in the colon. However, the up-regulated MMP-7 levels in the later stage of UC in the colon may also contribute to the tissue repair or be served as a marker to CRC （colorectal cancer）. The distribution of lysozyme protein indicates that there may be Paneth-like cells in the colon. Both the changes of MMP-7 and lysozyme in the small intestine may play a protective role for the safe environment of the whole gut, especially to the colon of UC.

Possible Role of Mast Cells and Neuropeptides in the Recovery Process of Dextran Sulfate Sodium-induced Colitis in Rats

Objective To clarify the role of mast cells and neuropeptides substance P （SP）, somatostatin （SS）, and vasoactive intestinal peptide （VIP） in dextran sulfate sodium （DSS）-induced colitis in rats. Methods Experimental colitis was induced in Sprague-Dawley rats （180-200 g, n=20） by oral in- gestion of 4% （w/v） DSS in drinking water for 7 days. Control rats （n=5） drank water and were sacrificed on day 0. Mast cell number, histamine levels in whole blood and tissue, tissue levels of SP, SS and, VIP in the dis- tal colon of the rats were measured on day 8, day 13, and day 18 of experimentation. Results Oral administration of 4% DSS solution for 7 days resulted in surface epithelial loss and crypt loss in the distal colon. Mast cell count increased on day 8 （1.75±1.09/mm vs. 0.38±0.24/mm, P〈0.05） and day 13 （1.55±1.01/mm vs. 0.38±0.24/mm, P〈0.05） after DSS treatment. Whole blood his- tamine levels were increased on day 8 （266.93±35.62 ng/mL vs. 76.87±32.28 ng/mL, P〈0.01） and gradu- ally decreased by clay 13 and day 18 after DSS treatment. Histamine levels in the distal colon were decreased on day 8 （1.77±0.65 ng/mg vs. 3.06±0.87 ng/mg, P〈0.05） and recovered to control levels by day 13 after DSS treatment. SP level in the distal colon gradually increased and were raised significantly by day 13 （8777.14±3056.14 pg/mL vs. 4739.66±3299.81 pg/mL, P〈0.05） after DSS treatment. SS and VIP levels in the distal colon were not changed. Conclusions Mast cell degranulation followed by histamine release may play an important role in the pathogenesis of colitis induced by DSS. SP may be a significant substance in the progression of inflamma- tion and the recovery process of DSS-induced colitis.

Effect of Yang-activating and stasis-eliminating decoction from Traditional Chinese Medicine on intestinal mucosal permeability in rats with ulcerative colitis induced by dextran sulfate sodium

OBJECTIVE: To evaluate the effect of decoction prepared with Yang-activating and stasis-eliminating medicinals from Traditional Chinese Medicine(TCM) on the intestinal mucosal permeability in rats with ulcerative colitis induced by dextran sulfate sodium(DSS).METHODS: Totally 55 male Wistar rats(body weight of 170-190 g) were randomly divided into the blank group(n = 10) and the model duplication group(n = 45). The blank group was not intervened, while the other was modeled with 5% dextran sulfate sodium by gavaging in a dosage of4 m L per day to induce ulcerative colitis, a total of7 days. Then, the model rats were divided into model blank group, mesalazine group and TCM group,and each group was consisted of 15 rats. They were given retention enema 10 min with normal saline,mesalazine enema(0.036 g/m L), and Yang-activating and stasis-eliminating decoction [0.54 g/m L of a decoction boiled by Puhuang(Pollen Typhae), Xiebai(Bulbus Allii Macrostemonis) and Wulingzhi(Faeces Trogopteri)] for 10 days respectively. Afterwards,all of the rats were evaluated by disease activity index(DAI), histological changes of distal colon, expression of occludin protein and ultrastructure of intestinal epithelial cells. Furthermore, ratio of lactulose to mannitol(L/M) discharged in urine was evaluated.RESULTS: Comparing the results between TCM and model control groups, scores of DAI and histological lesions decreased significantly(P = 0.000 <0.01), ultrastructures of intestinal epithelial cells and tight junctions were more complete. The expression of occludin protein(P = 0.001 < 0.01) increased while the L/M value decreased significantly(P = 0.000 < 0.01) in TCM group. There was no statistical difference between the TCM and mesalazine groups in results of each item(P > 0.05).CONCLUSION: The decoction prepared with Yang-activating and stasis-eliminating TCM medicianls can restore intestinal mucosal epithelial cells and tight junctions the model rats with ulcerative colitis; it can reduce histological lesions and protect the permeability of intestinal mucosa barrier in the rats as well.

The Involvement of Ca^2＋ Signal Pathways in Distal Colonic Myocytes in a Rat Model of Dextran Sulfate Sodium-induced Colitis

Background： Disrupted 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. Methods： Male 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. Results： Average 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. Conclusions： Impaired intracellular Ca2＋ signaling of colonic SM, caused by alteration of Ca2＋ handing proteins, contribute to colonic dysmotility in DSS-induced UC.

New approach of medicinal herbs and sulfasalazine mixture on ulcerative colitis induced by dextran sodium sulfate

BACKGROUND Sulfasalazine has been used as a standard-of-care in ulcerative colitis for decades,however,it results in severe adverse symptoms,such as hepatotoxicity,blood disorders,male infertility,and hypospermia.Accordingly,the new treatment strategy has to enhance pharmacological efficacy and stimultaneously minimize side effects.AIM To compare the anti-inflammatory action of sulfasalazine alone or in combination with herbal medicine for ulcerative colitis in a dextran sodium sulfate(DSS)-induced colitis mouse model.METHODS To induce ulcerative colitis,mice received 5%DSS in drinking water for 7 d.Animals were divided into five groups(n=9 each)for use as normal(non-DSS),DSS controls,DSS+sulfasalazine(30 mg/kg)-treatment experimentals,DSS+sulfasalazine(60 mg/kg)-treatment experimentals,DSS+sulfasalazine(30 mg/kg)+Citrus unshiu peel and Bupleuri radix mixture(30 mg/kg)(SCPB)-treatment experimentals.RESULTS The SCPB treatment showed an outstanding effectiveness in counteracting the ulcerative colitis,as evidenced by reduction in body weight,improvement in crypt morphology,increase in antioxidant defenses,down-regulation of proinflammatory proteins and cytokines,and inhibition of proteins related to apoptosis.CONCLUSIONSCPB may represent a promising alternative therapeutic against ulcerative colitis,without inducing adverse effects.

Protective Effect of Total Alkaloids of Sophora Alopecuroides on Dextran Sulfate Sodium-Induced Chronic Colitis

Objective：To investigate the effect of total alkaloids of Sophora alopecuroides（TASA） on dextran sulfate sodium（DSS）-induced colitis in mice.Methods：Chronic experimental colitis was induced by administration of 4 cycles of 4%DSS.Fifty mice were randomly distributed into 4 groups（normal,DSS,DSS/high-dose TASA, and DSS/low-dose TASA groups） by a random number table with body weight stratification.Mice in the normal group（n=11） and DSS-induced colitis control group（n=15） received control treatment of 20 mL/kg distilled water; DSS plus TASA high- and low-dose groups（n=12 each） were treated with TASA solution（20 mL/kg） at the doses of 60 mg/kg and 30 mg/kg,respectively.The severity of colitis was assessed on the basis of clinical signs, colon length,and histology scores.Moreover,secretory immunoglobulin A（slgA） and haptoglobin（HP） were analyzed by enzyme linked immunosorbent assay;intercellular adhesion molecule 1（ICAM-1） and macrophage-migration inhibitory factor（MIF） gene expressions were analyzed by quantitative reverse transcriptase realtime polymerase chain reaction（qRT-PCR） using SYBA greenⅠ;and nuclear factorκB（NF-κB） expression and activation and p65 interaction with the promoter of ICAM-1 gene were assessed by Western blotting and chromatin immunoprecipitation assay.Results：TASA administration significantly attenuated the damage and substantially reduced HP elevation and maintained the level of cecum slgA.TASA inhibited the ICAM-1 gene expression and had no effect on MIF gene expression.Also,TASA was able to reduce phospho-lκBα（p-lκBα） protein expression;however,it had no effect on the activation of IκB kinaseα（IKKα） and inhibitor of NF-κBα（IκBα）.Moreover,TASA inhibited the p65 recruitment to the ICAM-1 gene promoter.Conclusions：TASA had a protective effect on DSS-induced colitis.Such effect may be associated with its inhibition of NF-κB activation and blockade of NF-κB-regulated transcription activation of proinflammatory mediator gene.