Spirulina platensis aqueous extracts ameliorate colonic mucosal damage and modulate gut microbiota disorder in mice with ulcerative colitis by inhibiting inflammation and oxidative stress / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

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.

Mechanism of Sanhuang Decoction in alleviating dextran sulfate sodium induced ulcerative colitis in mice with Candida albicans colonization:based on high-throughput transcriptome sequencing / 中国中药杂志

This study explored the mechanism of Sanhuang Decoction(SHD) in treating dextran sulfate sodium(DSS)-induced ulcerative colitis(UC) in mice with Candida albicans(Ca) colonization via high-throughput transcriptome sequencing. Specifically, the animal model was established by oral administration of 3.0% DSS for 7 days followed by intragastrical administration of Ca suspension at 1.0 × 10~8 cells for 4 days and then the mice were treated with SHD enema for 7 days. Afterwards, the general signs were observed and the disease activity index(DAI) was recorded every day. After mice were sacrificed, colon length and colon mucosa damage index(CMDI) were determined and the histomorphology was observed with the HE staining method. The fungal loads of feces were detected with the plate method. Anti-saccharomyces cerevisiae antibody(ASCA) and β-1,3-glucan in serum, and TNF-α, IL-1β, and IL-6 in serum and colon were detected by ELISA. High-throughput RNA sequencing method was adopted to identify transcriptome of colon tissues from the control, model and SHD(15.0 g·kg~(-1)) groups. Differentially expressed genes(DEGs) among groups were screened and the GO and KEGG pathway enrichment analysis of the DEGs was performed. The expression levels of NLRP3, ASC, caspase-1, and IL-1β genes related to the NOD-like receptor signaling pathway which involved 9 DEGs, were examined by qRT-PCR and Western blot. The results demonstrated that SHD improved the general signs, decreased DAI and Ca loads of feaces, alleviated colon edema, erosion, and shortening, and lowered the content of β-1,3-glucan in serum and TNF-α, IL-1β, and IL-6 in serum and colon tissues of mice. Transcriptome sequencing revealed 383 DEGs between SHD and model groups, which were mainly involved in the biological processes of immune system, response to bacterium, and innate immune response. They were mainly enriched in the NOD-like signaling pathway, cytokine-cytokine interaction pathway, and retinol metabolism pathway. Moreover, SHD down-regulated the mRNA and protein levels of NLRP3, caspase-1, and IL-1β. In a word, SHD ameliorates DSS-induced UC in mice colonized with Ca, which probably relates to its regulation of NOD-like receptor signaling pathway.

Effect of Banxia Xiexin Decoction on intestinal flora of mice with ulcerative colitis induced by dextran sodium sulfate / 中国中药杂志

The aim of this paper was to investigate the effect of Banxia Xiexin Decoction(BXD) on inflammatory factors and intestinal flora in a dextran sulfate sodium induced ulcerative colitis(DSS-UC) mouse model, and to explore the mechanism of BXD in treating ulcerative colitis from the perspective of flora disorder. Forty C57 BL/6 J mice were randomly divided into control group, model group and BXD group. A 2.5% DSS-induced ulcerative colitis model was established. On the 8 th day, normal saline, normal saline, and BXD were given daily for 14 days. After 14 days, HE staining was used to observe histopathological changes of the colon. Serum inflammatory factor content was detected by ELISA, and the change of intestinal flora in mice feces was detected by 16 S rRNA sequencing technology. Compared with control group, the colonic tissue of mice in model group was damaged seriously, and the contents of IL-6 and TNF-α in serum were significantly increased(P<0.05). Compared with model group, mice in BXD group had less colonic damage, and the contents of IL-6, TNF-α in serum were decreased significantly(P<0.05). After creation, the richness of Patescibacteria was increased significantly at the phylum level(P<0.05). At the same time, the richness of Faecalibaculum(P<0.01), norank_f_Muribaculaceae(P<0.01) were decreased significantly at the genus level, while the richness of Turicibacter(P<0.01), Romboutsia(P<0.01), Clostridium_sensu_stricto_1(P<0.01) were increased significantly. After the intervention with BXD, the content of Patescibacteria was significantly reduced at the phylum level(P<0.05), and the contents of Lactobacillus(P<0.01), Clostri-dium_sensu_stricto_1(P<0.01), Enterorhabdus(P<0.01), Candidatus_Saccharimonas(P<0.05), Eubacterium_fissicatena_group(P<0.05) were decreased significantly at the genus level, while the contents of Dubosiella, Bacteroides and Allobaculum were increased significantly. Therefore, BXD could significantly improve the symptoms of DSS-UC mice. It not only could reduce the contents of IL-6 and TNF-α, but also could reduce the richness of Patescibacteria at the phylum level, and those of Clostridium_sensu_stricto_1, Candidatus_Saccharimonas, Eubacterium_fissicatena_group at the genus level. Inaddition, BXD could increase the richness of Bacteroides and Bifidobacterium. It suggested that BXD could play a role in the treatment of ulcerative colitis partially through reducing inflammatory factors and regulating the structure of the gut microbiota.

Protective effect of Pai-Nong-San against AOM/DSS-induced CAC in mice through inhibiting the Wnt signaling pathway / 中国天然药物

Pai-Nong-San (PNS), a prescription of traditional Chinese medicine, has been used for years to treat abscessation-induced diseases including colitis and colorectal cancer. This study was aimed to investigate the preventive effects and possible protective mechanism of PNS on a colitis-associated colorectal cancer (CAC) mouse model induced by azoxymethane (AOM)/dextran sodium sulfate (DSS). The macroscopic and histopathologic examinations of colon injury and DAI score were observed. The inflammatory indicators of intestinal immunity were determined by immunohistochemistry and immunofluorescence. The high throughput 16S rRNA sequence of gut microbiota in the feces of mice was performed. Western blot was used to investigate the protein expression of the Wnt signaling pathway in colon tissues. PNS improved colon injury, as manifested by the alleviation of hematochezia, decreased DAI score, increased colon length, and reversal of pathological changes. PNS treatment protected against AOM/DSS-induced colon inflammation by regulating the expression of CD4

Protective effect of alcoholic extract of stem of Entada pursaetha in dextran sulphate sodium-induced colitis in mice.

Oxidative stress has been shown to play a critical role in the pathogenesis of ulcerative colitis (UC). Entada pursaetha has been demonstrated to have antioxidant and anti-inflammatory effects. In this study, we investigated the effects of stem of alcoholic extract of E. pursaetha (PSE) in dextran sodium sulfate (DSS)-induced colitis in mice. The protective effect of PSE was determined at three different doses of 30, 100 and 300 mg/kg body weight by oral gavage for 7 days. Morphological (colon length and colon weight/length ratio), clinical (disease activity index) and macroscopic (damage score) features were determined using standard criteria. Lipid peroxides (determined as malonaldehyde; MDA), enzymatic (superoxide dismutase; SOD and catalase; CAT) and non- enzymatic antioxidants (reduced glutathione; GSH), nitrate and nitrite (NOx) levels and myeloperoxidase (MPO) activity in colon tissues were determined. The DSS damaged the colonic tissue, increased MPO activity, lipid peroxidation and NOx levels, reduced the antioxidant enzymes and glutathione and lowered the body weight. PSE significantly reduced the inflammation of colon and reversed the increase in MPO activity induced by DSS. It also significantly increased the SOD and catalase activities and did not elicit any effect on depleted levels of GSH in the colonic tissue. In addition, PSE also significantly decreased colonic NOx and MDA levels compared to DSS-treated mice; reduced both infiltration of inflammatory cells and the mucosal damage in colon on histopathological examination. The results suggested the protective potential of PSE in DSS-induced colitis and this might be attributed to its anti-inflammatory and antioxidant activities.

Benzoxazole Derivative B-98 Ameliorates Dextran Sulfate Sodium-induced Acute Murine Colitis and the Change of T Cell Profiles in Acute Murine Colitis Model / 대한소화기학회지

BACKGROUND/AIMS: The unique role of enzyme 5-lipoxygenase (5-LO) in the production of leukotrienes makes it a therapeutic target for inflammatory bowel disease (IBD). The aim of this study was to evaluate the effects of B-98, a newly synthesized benzoxazole derivatives and a novel 5-LO inhibitor, in a mouse model of IBD induced by dextran sulfate sodium (DSS). METHODS: C57BL/6 mice were randomly assigned to four groups: normal control, DSS colitis (DSS+saline), low dose B-98 (DSS+B-98 20 mg/kg) and high dose B-98 (DSS+B-98 100 mg/kg). B-98 was administered with 3% DSS intraperitoneally. The severity of the colitis was assessed via the disease activity index (DAI), colon length, and histopathologic grading. The production of inflammatory cytokines interleukin (IL)-6 was determined by RT-PCR. Th cells were examined for the proportion of Th1 cell, Th2 cell, Th9 cell, Th17 cell and Treg cell using intracellular cytometry. RESULTS: The B-98 group showed lower DAI, less shortening of the colon length and lower histopathologic grading compared with the DSS colitis group (p<0.01). The expression of IL-6 in colonic tissue was significantly lower in the B-98 groups than the DSS colitis group (p<0.05). The cellular profiles revealed that the Th1, Th9 and Th17 cells were increased in the DSS colitis group compared to the B-98 group (p<0.05). CONCLUSIONS: Our results suggest that acute intestinal inflammation is reduced in the group treated with B-98 by Th1, Th9 and Th17 involved cellular immunity.

Parasitic Helminth Cystatin Inhibits DSS-Induced Intestinal Inflammation Via IL-10+F4/80+ Macrophage Recruitment

Many immune down-regulatory molecules have been isolated from parasites, including cystatin (cystain protease inhibitor). In a previous study, we isolated and characterized Type I cystatin (CsStefin-1) of the liver fluke, Clonorchis sinensis. To investigate whether the CsStefin-1 might be a new host immune modulator, we induced intestinal inflammation in mice by dextran sodium sulfate (DSS) and treated them with recombinant CsStefin-1 (rCsStefin-1). The disease activity index (DAI) increased in DSS only-treated mice. In contrast, the DAI value was significantly reduced in rCsStefin-1-treated mice than DSS only-treated mice. In addition, the colon length of DSS only-treated mice was shorter than that of rCsStefin-1 treated mice. The secretion levels of IFN-gamma and TNF-alpha in the spleen and mesenteric lymph nodes (MLNs) were significantly increased by DSS treatment, but the level of TNF-alpha in MLNs was significantly decreased by rCsStefin-1 treatment. IL-10 production in both spleen and MLNs was significantly increased, and IL-10+F4/80+ macrophage cells were significantly increased in the spleen and MLNs of rCsStefin-1 treated mice after DSS treatment. In conclusion, rCsStefin-1 could reduce the intestinal inflammation occurring after DSS treatment, these effects might be related with recruitment of IL-10 secreting macrophages.

Triptolide downregulates Rac1 and the JAK/STAT3 pathway and inhibits colitis-related colon cancer progression

Triptolide, a diterpenoid triepoxide from the traditional Chinese medicinal herb Tripterygium wilfordii Hook. f., is a potential treatment for autoimmune diseases as well a possible anti-tumor agent. It inhibits proliferation of coloretal cancer cells in vitro and in vivo. In this study, its ability to block progress of colitis to colon cancer, and its molecular mechanism of action are investigated. A mouse model for colitis-induced colorectal cancer was used to test the effect of triptolide on cancer progression. Treatment of mice with triptolide decreased the incidence of colon cancer formation, and increased survival rate. Moreover, triptolide decreased the incidence of tumors in nude mice inoculated with cultured colon cancer cells dose-dependently. In vitro, triptolide inhibited the proliferation, migration and colony formation of colon cancer cells. Secretion of IL6 and levels of JAK1, IL6R and phosphorylated STAT3 were all reduced by triptolide treatment. Triptolide prohibited Rac1 activity and blocked cyclin D1 and CDK4 expression, leading to G1 arrest. Triptolide interrupted the IL6R-JAK/STAT pathway that is crucial for cell proliferation, survival, and inflammation. This suggests that triptolide might be a candidate for prevention of colitis induced colon cancer because it reduces inflammation and prevents tumor formation and development.