Pectic polysaccharides ameliorate the pathology of ulcerative colitis in mice by reducing pyroptosis.

Background: Ulcerative colitis (UC) is an inflammatory bowel disease which seriously affects the quality of life of patients. There has been an increasing amount of research related to the therapeutic effects and mechanisms of natural plant substances in the treatment of recurrent UC. Rauwolfia verticillata var. Hainanensis is a medicinal plant that is native to Hainan Island, China. Some studies have documented that pectic polysaccharides (PPs) from Rauvolfia inhibited the progression of colon ulcers. However, their mechanisms of action have not been established. Studies have revealed that suppressing pyroptosis can attenuate the damage of experimental colitis. However, it is unclear whether PPs from Rauvolfia verticillata inhibit inflammation through pyroptosis. This study investigated the effects and potential mechanisms of PPs extracted from Rauvolfia verticillata on experimental UC in mice. Methods: Male C57 mice (6-8 weeks old) were allocated into the control group, the dextran sulfate sodium (DSS)-induced UC model group (DSS group), or the DSS with pectic polysaccharides treatment group (DSS + PP group). The body weights, rectal bleeding, and stool consistencies in the mice were observed, and the disease activity index (DAI) score was calculated. Colon tissues were collected for pathological analysis by histological hematoxylin and eosin (H&E) staining. The levels of caspase-1 and interleukin (IL)-1ß were detected by immunohistochemistry. Pyroptosis was assessed by transmission electron microscopy. Results: UC in mice induced by DSS resulted in decreased general physical activity and body weight, increased DAI score, significant histological changes, inhibited caspase-1 and IL-1ß expression, and promoted pyroptosis. These DSS-induced changes could be partially ameliorated by administration of PP. Conclusions: PPs exerted an ameliorative effect on DSS-induced UC in mice by reducing pyroptosis.

Mechanism of M2 macrophage-derived extracellular vesicles carrying lncRNA MEG3 in inflammatory responses in ulcerative colitis.

Ulcerative colitis (UC) is a chronic inflammatory disease of the colon. M2 macrophages possess certain anti-inflammation activity. Accordingly, the current study set out to investigate the potential mechanism of M2 macrophage-derived extracellular vesicles (M2-EVs) in UC inflammation. Firstly, mouse peritoneal macrophages were induced to M2 phenotype, and M2-EVs were isolated. , the murine model of UC was established, and the length and weight of the colon, disease activity index (DAI), apoptosis, and inflammatory response of UC mice were measured. Young adult mouse colon (YAMC) cells were induced with the help of lipopolysaccharide. LncRNA maternally expressed 3 (LncRNA MEG3), miR-20b-5p, and cAMP responsive element binding protein 1 (CREB1) expression patterns were detected in UC models. In addition, we analyzed the binding relationship among MEG3, miR-20b-5p, and CREB1. UC mice presented with shortened colon length, lightened weight, increased DAI score, enhanced apoptosis, and significant inflammatory cell infiltration, while M2-EVs reversed these trends. In vitro, M2-EVs increased UC cell viability and reduced inflammation. Mechanistic experimentation revealed that M2-EVs transferred MEG3 into YAMC cells to up-regulate MEG3 expression and promote CREB1 transcription by competitively binding to miR-20b-5p. Moreover, up-regulation of MEG3 in M2-EVs enhanced the protective effect of M2-EVs on UC cells, while over-expression of miR-20b-5p attenuated the aforementioned protective effect of M2-EVs on UC mice and cells. Collectively, our findings revealed that M2-EVs carrying MEG3 enhanced UC cell viability and reduced inflammatory responses via the miR-20b-5p/CREB1 axis, thus alleviating UC inflammation.

Rauwolfia vomitoria Extract Represses Colorectal Cancer Cell Autophagy and Promotes Apoptosis.

BACKGROUND: Colorectal cancer (CRC) is one of the most frequent digestive tract tumors in the world with an increasing incidence. Currently, surgical resection and chemotherapy are the main therapeutic options; however, their effects are limited by various adverse reactions. Rauwolfia vomitoria extract (Rau) has been shown to repress the progression of multiple human cancers; however, whether Rau plays a role in CRC remains undetermined. METHODS: Influences of Rau treatment on HCT-116 and LoVo cells were estimated via MTT and colony formation experiments. Flow cytometry analysis was adopted to evaluate the apoptosis rate of HCT-116 and LoVo cells. Apoptosis-related proteins (Bcl-2, Bax, and caspase-3) and autophagy-related proteins (LC3 and P62) were assessed by Western blotting. Effects of Rau on autophagy of HCT-116 and LoVo cell were evaluated through GFP-LC3 analysis. In vivo xenograft tumor assay was conducted to further examine the role of Rau in CRC tumor growth. RESULTS: Rau remarkably repressed HCT-116 and LoVo cell viability and promoted HCT-116 and LoVo cell apoptosis in vitro in a dose-dependent manner. Rau increased the expression of caspase-3 and Bax and decreased the expression of Bcl-2 in HCT-116 and LoVo cells. Moreover, Rau was demonstrated to decrease the LC3||/LC3| ratio and increase the level of P62 in HCT-116 and LoVo cells. In addition, we found that Rau repressed xenograft tumor growth and also repressed autophagy in vivo. CONCLUSION: Our findings revealed that Rau repressed CRC cell viability and autophagy in vitro and in vivo, suggesting that Rau might be a potent therapeutic agent of CRC.

LncRNA CDKN2B-AS1 relieved inflammation of ulcerative colitis via sponging miR-16 and miR-195.

BACKGROUND: This study was aimed to explore the differential expression of lncRNA CDKN2B-AS1-miR-195-5p/miR-16-5p axis in ulcerative colitis (UC) and its role in regulating UC pathogenesis. METHODS: One hundred and eighty-seven UC patients and one hundred and fifty-two healthy volunteers were recruited, and their blood samples were collected. Inflammatory cytokines in serum were determined with ELISA, and lncRNA CDKN2B-AS1, miR-195-5p and miR-16-5p levels were detected with RT-PCR. Then pcDNA3.1-CDKN2B-AS1, si-CDKN2B-AS1, miR-195-5p mimic, miR-195-5p inhibitor, miR-16-5p mimic and miR-16-5p inhibitor were transfected into HT29 cells, and proliferation and apoptosis of the cells were assessed. Dual-luciferase reporter gene assay was implemented to identify the sponging relationship between lncRNA CDKN2B-AS1 and miR-195-5p/miR-16-5p. RESULTS: CDKN2B-AS1 level was negatively correlated with levels of inflammatory cytokines, including TNF-α, IL-6 and sIL-2R, yet miR-16-5p and miR-195-5p levels were negatively correlated with the CDKN2B-AS1 level. The CDKN2B-AS1 combined with miR-16-5p and miR-195-5p also achieved an optimum efficacy in differentiating between light and medium UC, light and severe UC, as well as medium and heavy UC. Furthermore, pcDNA3.1-CDKN2B-AS1 depressed expressions of IFN-γ, IL-8, IL-1ß and TNF-α in HT29 cells (P < 0.05), and strengthened proliferation of the cells (P < 0.05). CDKN2B-AS1 also sponged and regulated miR-16-5p and miR-195-5p in HT29 cells, and miR-16-5p and miR-195-5p could reverse the effect of CDKN2B-AS1 on inflammatory cytokine production, barrier function and apoptosis of HT29 cells (P < 0.05). CONCLUSION: LncRNA CDKN2B-AS1 regulated inflammation of UC by sponging miR-195-5p and miR-16-5p, providing an alternative for diagnosis and treatment of UC.

Long non-coding RNA Mirt2 interacts with long non-coding RNA IFNG-AS1 to regulate ulcerative colitis.

Long non-coding RNAs (lncRNAs) Mirt2 and interferon-γ antisense RNA I (IFNG-AS1) play opposing roles in lipopolysaccharide (LPS)-induced inflammation, a key initiator of ulcerative colitis (UC). The present study aimed to analyze the potential interaction between Mirt2 and IFNG-AS1 in UC. Levels of IFNG-AS1 and Mirt2 in plasma samples from UC patients were measured using reverse transcription-quantitative PCR. Receiver operating characteristic curves were used to evaluate the diagnostic values of IFNG-AS1 and Mirt2 fr UC. The role of Mirt2 and IFNG-AS1 in colonic epithelial cell apoptosis was analyzed by cell apoptosis assay. In patients with UC, Mirt2 and IFNG-AS1 exhibited an inverse correlation, in which Mirt2 was downregulated while IFNG-AS1 was upregulated. Altered expression of IFNG-AS1 and Mirt2 separated patients with UC from healthy controls. In colonic epithelial cells, lipopolysaccharide treatment led to the downregulation of Mirt2 and the upregulation of IFNG-AS1. Furthermore, overexpression of Mirt2 in colonic epithelial cells resulted in downregulation of IFNG-AS1, and vice versa. Overexpression of Mirt2 led to a decreased rate of colonic epithelial cell apoptosis, while overexpression of IFNG-AS1 led to an increased rate of apoptosis. Moreover, IFNG-AS1 overexpression attenuated the effects of Mirt2 overexpression. Therefore, Mirt2 may interact with IFNG-AS1 during UC to participate in colonic epithelial cell apoptosis.

Pectic polysaccharides extracted from Rauvolfia verticillata (Lour.) Baill. var. hainanensis Tsiang ameliorate ulcerative colitis via regulating the MAPKs and NF-κB pathways in dendritic cells.

This study was to investigate the effects and mechanisms of pectic polysaccharides (PP) extracted from Rauvolfia verticillata (Lour.) Baill. var. hainanensis Tsiang on dextran sulphate sodium (DSS)-induced ulcerative colitis (UC). Eighty female BALB/c mice were randomly divided into four groups: Control, DSS, DSS + salicylazosulfapyridine (SASP), and DSS+ PP. The disease activity index (DAI), overall physical activity, and blood stool were monitored daily to evaluate severity of UC. Histological scores of the colon were observed. The expression of nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPKs) pathways in colon tissues and bone marrow-derived dendritic cells (DCs) was assessed by western blot, immunohistochemistry, electrophoretic mobility shift assay (EMSA) and real time polymerase chain reaction (RT-PCR). Cytokines were measured by enzyme-linked immunosorbent assay (ELISA). The overall physical activity, DAI and histological scores decreased in DSS+SASP and DSS+PP groups, compared with the DSS-alone group. Also, tumour necrosis factor α (TNF-α) and interleukin 6 (IL-6) reduced significantly while the expression of IκBα was up-regulated, extracellular signal-regulated kinase (ERK), Jun N-terminal kinase (JNK) and p38 were activated, in DSS+SASP and DSS+PP groups. PP inhibited activation of MAPKs and NF-κB pathways in the bone-marrow-derived DCs. In conclusion, PP significantly ameliorated murine DSS-induced UC model, via regulation of MAPKs and NF-κB pathways in DCs.

Suppressive effect of pectic polysaccharides extracted from Rauwolfia verticillata (Lour.) Baill.var.hainanensis Tsiang on inflammation by regulation of NF- κ B pathway and interleukin-17 in mice with dextran sulphatesodium-induced ulcerative colitis.

OBJECTIVE: To investigate the effects of pectic polysaccharides extracted from Rauwolfia verticillata (Lour.) Baill.var.hainanensis Tsiang on an experimental murine colitis model. METHODS: Experimental colitis was induced by dextran sulfate sodium (DSS), and mice were divided into 4 groups: control, DSS alone, DSS plus SASP, DSS plus pectic polysaccharides. The disease activity index (DAI) and histological score were observed. The tumor necrosis factor (TNF)- α and interleukin (IL)-17 levels were measured by enzyme-linked immunosorbent assay. I κ B and NF- κ B p65 expression were assessed by western blot analysis. Myeloperoxidase (MPO) activity was determined by using MPO assay kit. RESULTS: Administration of pectic polysaccharides significantly reduced the severity of DSS-induced colitis as assessed by DAI and histological score, and resulted in down regulation of MPO activity and NF- κ B p65 expression and subsequent degradation of I κ B protein, strikingly reduced the production of TNF- a and IL-17. CONCLUSIONS: Pectic polysaccharides extracted from Rauvolfia verticillata (Lour.)Baill.var. hainanensis Tsiang exerts beneficial effects in experimental colitis and may therefore provide a useful therapeutic approach for the treatment of UC.