Schisandra chinensis (Turcz.) Baill. Protects against DSS-induced colitis in mice: Involvement of TLR4/NF-κB/NLRP3 inflammasome pathway and gut microbiota.

the fruit of Schisandra chinensis (Turcz.) Baill. (SC) is an important traditional Chinese herbal medicine, which has been widely used in traditional Chinese medicine (TCM) for treating intestinal diseases. It is also traditionally used as health product and medicine in Russia and other countries. However, the effect of SC ethanol extract on anti-ulcerative colitis (UC) has not been systematically studied yet. We investigated the protective effects and underlying action mechanisms of SC extract (SCE) for UC treatment. An animal model of UC induced by dextran sulfate sodium (DSS) was established. After oral administration of SCE, the Disease Activity Index (DAI) was calculated, the length of colon measured, levels of proinflammatory factors determined, and histopathology carried out to assess the therapeutic efficacy of SCE on UC. The effects of SCE on the toll-like receptor 4/nuclear factor-kappa B/nucleotide-binding and oligomerization domain-like receptor family pyrin domain containing 3 inflammasome (TLR4/NF-κB/NLRP3 inflammasome) signaling pathway were evaluated by western blotting. High-throughput sequencing was done to reveal the effect of SCE on the change of the gut microbiota (GM) in mice with DSS-induced colitis. SCE significantly reduced the DAI score, restored colon-length shortening, and ameliorated colonic histopathologic injury in mice with DSS-induced colitis. SCE inhibited the inflammatory response by regulating the TLR4/NF-κB/NLRP3 inflammasome pathway in mice with UC. SCE also maintained gut barrier function by increasing the levels of zonula occludens (ZO)-1 and occludin. 16S rRNA sequencing showed that SCE could reverse the GM imbalance caused by UC. SCE can ameliorate DSS-induced colitis, and that its effects might be associated with suppression of the TLR4/NF-κB/NLRP3 inflammasome pathway and GM regulation, which may provide significant supports for the development of potential candidates for UC treatment.

Bian Z ，Qin Y ，Li L ，Su L ，Fei C ，Li Y ，Hu M ，Chen X ，Zhang W ，Mao C ，Yuan X ，Lu T ，Ji D ... -  《-》

Canna x generalis L.H. Bailey rhizome extract ameliorates dextran sulfate sodium-induced colitis via modulating intestinal mucosal dysfunction, oxidative stress, inflammation, and TLR4/ NF-ҡB and NLRP3 inflammasome pathways.

Genus Canna is used in folk medicine as demulcent, diaphoretic, antipyretic, mild laxative and in gastrointestinal upsets therapy. Canna x generalis (CG) L.H. Bailey is traditionally used as anti-inflammatory, analgesic and antipyretic. Besides, CG is used in Ayurvedic medicines' preparations and in the treatment of boils, wounds, and abscess. Nevertheless, its anti-inflammatory effects against ulcerative colitis (UC) are not yet investigated. This study aimed to investigate the phytoconstituents of CG rhizome ethanol extract (CGE). Additionally, we aimed to comparatively evaluate its therapeutic effects and underlying mechanisms against the reference drug "sulphasalazine (SAS)" in dextran sodium sulfate (DSS)-induced UC in mice. Metabolic profiling of CG rhizomes was performed via UHPLC/qTOF-HRMS; the total phenolic, flavonoid and steroid contents were determined, and the main phytoconstituents were isolated and identified. Next, DSS-induced (4%) acute UC was established in C57BL/6 mice. DSS-induced mice were administered either CGE (100 and 200 mg/kg) or SAS (200 mg/kg) for 7 days. Body weight, colon length, disease activity index (DAI) and histopathological alterations in colon tissues were examined. Colon levels of oxidative stress (GSH, MDA, SOD and catalase) and pro-inflammatory [Myeloperoxidase (MPO), nitric oxide (NO), IL-1β, IL-12, TNF-α, and INF-γ] markers were colourimetrically determined. Serum levels of lipopolysaccharide (LPS) and relative mRNA expressions of occludin, TLR4 and ASC (Apoptosis-Associated Speck-Like Protein Containing CARD) using RT-PCR were measured. Protein levels of NLRP3 inflammasome and cleaved caspase-1 were determined by Western blot. Furthermore, immunohistochemical examinations of caspase-3, NF-ҡB and claudin-1 were performed. Major identified constituents of CGE were flavonoids, phenolic acids, phytosterols, beside five isolated phytoconstituents (β-sitosterol, triacontanol fatty alcohol, β-sitosterol-3-O-β-glucoside, rosmarinic acid, 6-O-p-coumaroyl-β-D-fructofuranosyl α-D-glucopyranoside). The percentage of the phenolic, flavonoid and steroid contents in CGE were 20.55, 6.74 and 98.09 μg of gallic acid, quercetin and β-sitosterol equivalents/mg extract, respectively. In DSS-induced mice, CGE treatment ameliorated DAI, body weight loss and colon shortening. CGE attenuated the DSS-induced colonic histopathological alternations, inflammatory cell infiltration and histological scores. CGE elevated GSH, SOD and catalase levels, and suppressed MDA, pro-inflammatory mediators (MPO and NO) as well as cytokines levels in colonic tissues. Moreover, CGE downregulated LPS/TLR4 signaling, caspase-3 and NF-ҡB expressions. CGE treatment inhibited NLRP3 signaling pathway as indicated by the suppression of the protein expression of NLRP3 and cleaved caspase-1, and the ASC mRNA expression in colonic tissues. Additionally, CGE restored tight junction proteins' (occludin and claudin-1) expressions. Our findings provided evidence for the therapeutic potential of CGE against UC. CGE restored intestinal mucosal barrier's integrity, mitigated oxidative stress, inflammatory cascade, as well as NF-ҡB/TLR4 and NLRP3 pathways activation in colonic tissues. Notably, CGE in a dose of 200 mg/kg was more effective in ameliorating DSS-induced UC as compared to SAS at the same dose.

Mahmoud TN ，El-Maadawy WH ，Kandil ZA ，Khalil H ，El-Fiky NM ，El Alfy TSMA ... -  《-》

The protective effect of Schisandra chinensis (Turcz.) Baill. polysaccharide on DSS-induced ulcerative colitis in mice via the modulation of gut microbiota and inhibition of NF-κB activation.

Guo X ，Liu L ，Zhao W ，Li X ，Wang X ，Ning A ，Cao J ，Zhang W ，Cao L ，Zhong M ... -  《-》

Gegen Qinlian decoction ameliorates TNBS-induced ulcerative colitis by regulating Th2/Th1 and Tregs/Th17 cells balance, inhibiting NLRP3 inflammasome activation and reshaping gut microbiota.

Chinese herbal medicine Gegen Qinlian Decoction (GQD) has been clinically shown to be an effective treatment of ulcerative colitis (UC) in China. However, the underlying mechanism of GQD's anti-ulcerative colitis properties and its effect on gut microbiota still deserve further exploration. This study observed the regulatory effects of GQD on Th2/Th1 and Tregs/Th17 cells balance, the NOD-like receptor family pyrin domain containing 3 (NLRP3) infammasome and gut microbiota in TNBS-induced UC in BALB/c mice. 61 main chemical compounds in the GQD were determined by UPLC-Q-TOF/MS. The UC BALB/c model was established by intrarectal administration of trinitrobenzene sulfonic acid (TNBS), and GQD was orally administered at low and high dosages of 2.96 and 11.83 g/kg/day, respectively. The anti-inflammatory effects of GQD for ulcerative colitis were evaluated by survival rate, body weight, disease activity index (DAI) score, colonic weight and index, spleen index, hematoxylin-eosin (HE) staining and histopathological scores. Flow cytometry was used to detect the percentage of CD4, Th1, Th2, Th17 and Tregs cells. The levels of Th1-/Th2-/Th17-/Tregs-related inflammatory cytokines and additional proinflammatory cytokines (IL-1β, IL-18) were detected by CBA, ELISA, and RT-PCR. The expressions of GATA3, T-bet, NLRP3, Caspase-1, IL-Iβ, Occludin and Zonula occludens-1 (ZO-1) on colon tissues were detected by Western blot and RT-PCR. Transcriptome sequencing was performed using colon tissue and 16S rRNA gene sequencing was performed on intestinal contents. Fecal microbiota transplantation (FMT) was employed to assess the contribution of intestinal microbiota and its correlation with CD4 T cells and the NLRP3 inflammasome. GQD increased the survival rate of TNBS-induced UC in BALB/c mice, and significantly improved their body weight, DAI score, colonic weight and index, spleen index, and histological characteristics. The intestinal barrier dysfunction was repaired after GQD administration through promoting the expression of tight junction proteins (Occludin and ZO-1). GQD restored the balance of Th2/Th1 and Tregs/Th17 cells immune response of colitis mice, primarily inhibiting the increase in Th2/Th1 ratio and their transcription factor production (GATA3 and T-bet). Morever, GQD changed the secretion of Th1-/Th2-/Th17-/Tregs-related cytokines (IL-2, IL-12, IL-5, IL-13, IL-6, IL-10, and IL-17A) and reduced the expressions of IL-1β, IL-18. Transcriptome results suggested that GQD could also remodel the immune inflammatory response of colitis by inhibiting NOD-like receptor signaling pathway, and Western blot, immunohistochemistry and RT-PCR further revealed that GQD exerted anti-inflammatory effects by inhibiting the NLRP3 inflammasome, such as down-regulating the expression of NLRP3, Caspase-1 and IL-1β. More interestingly, GQD regulated gut microbiota dysbiosis, suppressed the overgrowth of conditional pathogenic gut bacteria like Helicobacter, Proteobacteria, and Mucispirillum, while the probiotic gut microbiota, such as Lactobacillus, Muribaculaceae, Ruminiclostridium_6, Akkermansia, and Ruminococcaceae_unclassified were increased. We further confirmed that GQD-treated gut microbiota was sufficient to relieve TNBS-induced colitis by FMT, involving the modulation of Th2/Th1 and Tregs/Th17 balance, inhibition of NLRP3 inflammasome activation, and enhancement of colonic barrier function. GQD might alleviate TNBS-induced UC via regulating Th2/Th1 and Tregs/Th17 cells Balance, inhibiting NLRP3 inflammasome and reshaping gut microbiota, which may provide a novel strategy for patients with colitis.

Hu Y ，Tang J ，Xie Y ，Xu W ，Zhu W ，Xia L ，Fang J ，Yu D ，Liu J ，Zheng Z ，Zhou Q ，Shou Q ，Zhang W ... -  《-》

Glycyrrhiza uralensis Fisch. alleviates dextran sulfate sodium-induced colitis in mice through inhibiting of NF-κB signaling pathways and modulating intestinal microbiota.

Licorice is widely used in traditional Chinese Medicine (TCM) for compound compatibility, which could reduce toxicity and increase efficacy of certain herbal medicine, and its active components prominently effects of inhibit of inflammation and regulate of immunity. The study probed into the mechanism of the anti-inflammatory and immunomodulatory effects of licorice based on the domination of the T helper type 17/regulatory T cells (Th17/Treg) differentiation balance and the composition and structure of the intestinal flora through the nuclear factor kappa B (NF-κB) signaling pathway. BALB/c mice were inoculated with dextran sulfate sodium (DSS) to establish animal models of ulcerative colitis (UC). For the pharmacodynamic study, UC mice were observed for the anti-inflammatory effect of licorice water extraction (LWE) in vivo, including clinical observation and measurement of colon length. Hematoxylin-eosin (HE) staining was used to evaluate pathological conditions. Immunohistochemistry (IHC) and transmission electron microscopy (TEM) were performed to observe the intestinal barrier of the colons. Inflammatory cytokine levels were measured using with enzyme-linked immunosorbent assay (ELISA) kits. The proportions of T helper (Th) cells in the colons was assessed using flow cytometry. Gut microbiota diversity was detected using 16S ribosomal (r)DNA sequencing. In addition, Western blot (WB) assays were used to verify ROR-γt, Foxp3, TLR4, MyD88 and NF-κB expression according to a standard protocol. LWE exerted a pharmacological anti-inflammatory effect by attenuating inflammation in the colonic tissues through affecting the protein expression of TLR4/MyD88/NF-κB, and increasing the expression of tight junction (TJ) protein in the colons, improving the integrity of the intestinal mucosal barrier in vivo. Moreover, LWE reversed the imbalance in Th17/Treg cells differentiation and influenced the protein expression of ROR-γt and Foxp3 in UC mouse colons. In particular, LWE significantly affected the diversity of the gut microbiota in UC mice, ameliorated the composition of dominant species, and significantly increased the type and quantity of probiotics. Licorice tends to reduce inflammation and enhance the protective action of the intestinal mucosal barrier via the TLR4/MyD88/NF-κB signal transduction pathway and alter the imbalance of Th-cell differentiation. Notably, licorice may affect the diversity of intestinal microbiota and the content of beneficial bacteria in the colon, which is a potential mechanism for understanding anti-inflammatory and immunomodulatory effects in UC mice in vivo.

Shi G ，Kong J ，Wang Y ，Xuan Z ，Xu F ... -  《-》