Black tea extract prevents lipopolysaccharide-induced NF-κB signaling and attenuates dextran sulfate sodium-induced experimental colitis

Incidental nanoparticles in black tea alleviate DSS-induced ulcerative colitis in BALB/c mice

As the dominant herbal drink consumed worldwide, black tea exhibits various health promoting benefits including amelioration of inflammatory bowel diseases. Despite extensive studies on the tea's components, little is known about the bioactivities of nanoparticles (NPs) which were incidentally assembled in the tea infusion and represent the major components. This study investigated the alleviative effects of black tea infusion, the isolated black tea NPs, and a mixture of caffeine, epigallocatechin-3-gallate, gallic acid and epicatechin gallate on dextran sodium sulfate (DSS)-induced ulcerative colitis. The results showed that both the black tea infusion and the NPs significantly alleviated colitis, suppressed the mRNA levels of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β, and suppressed the DSS-induced loss of cell-cell junction proteins (e.g., E-cadherin, ZO-1, and claudin-1) and increase of p-STAT3. The mixture of four tea components, which is the analogue of bioactive payloads carried by the NPs, was much less effective than the tea infusion and NPs. It shows that the NPs elevate the efficiency of polyphenols and caffeine in black tea in restoring the intercellular connection in the intestine, inhibiting mucosal inflammation, and alleviating ulcerative colitis. This work may inspire the development of tea-based therapeutics for treating inflammatory bowel diseases and have wide influences on value-added processing, quality evaluation, functionalization, and innovation of tea and other plant-based beverages.

Tea (Camellia sinensis) ameliorates DSS-induced colitis and liver injury by inhibiting TLR4/NF-κB/NLRP3 inflammasome in mice

The gut-liver axis is a bidirectional relationship between the gut with its microbiota and the hepatic. Ulcerative colitis (UC) disrupts the intestinal barrier and influx of intestinal microorganisms and their products into the liver, which trigger liver injury. Tea consumption is associated with a low incidence of UC in Asian countries. In this study, we revealed the mechanisms of six types of tea water extracts (TWEs) obtained from the leaves of Camellia sinensis on the dextran sodium sulfate (DSS)-induced colitis and liver injury in mice. The TWEs significantly restored mucin production and increased the expression levels of tight junction (TJ) proteins such as zonula occludens-1 (ZO-1), occluding, and claudin-1. In addition, TWEs also reduced the levels of pro-inflammatory cytokines in the colon and liver tissue by inactivating the NF-κB/NLRP3. Moreover, TEWs treatment promoted the integrity of the intestinal barrier to reduce serum lipopolysaccharide (LPS) levels, thereby reducing liver injury caused by intestinal microbial translocation and LPS induction. Analysis of 16 S rRNA microbial sequencing revealed that tea water extracts (TWEs) restored the DSS-induced gut dysbiosis. Interestingly, our results showed that the degree of fermentation of tea leaves was negatively associated with the alleviation of DSS-induced colitis effects, and there was also an overall negative trend with colitis-induced liver injury, except for black tea. Taken together, tea consumption mitigated DSS-induced colitis and liver injury in mice via inhibiting the TLR4/NF-κB/NLRP3 inflammasome pathway.

Therapeutic implications of functional tea ingredients for ameliorating inflammatory bowel disease: a focused review

Inflammatory bowel disease (IBD) is a chronic gastro-intestinal disorders of unknown etiology. There are several drugs approved for treating IBD patients with active disease, including first-line use of aminosalicylates, and secondary choices of immunomodulators and other therapies. These medications might manage disease symptoms, but have also shown significant side-effects in IBD patients. Tea is the second largest beverage in the world and its main active ingredients including tea polyphenols, polysaccharides and tea pigments have been shown promising anti-inflammatory and antioxidant properties. In this review, we summarize the influence of different tea varieties including green tea, black tea and dark tea as potential nutritional therapy for preventing and treating IBD, and discuss the mechanisms of tea ingredients involved in the regulation of oxidative stress, inflammation, signaling pathways, and gut microbiota that could benefit for IBD disease management. Our observation directs further basic and clinical investigations on tea polyphenols and their derivatives as novel IBD therapeutic agents.

Hot-water extract of ripened Pu-erh tea attenuates DSS-induced colitis through modulation of the NF-κB and HIF-1α signaling pathways in mice

Tea consumption has been found to be associated with low incidence of inflammatory bowel disease in Asian countries. However, there is very limited knowledge of such potential protection and its underlying mechanism. Ripened Pu-erh tea (RPT) belongs to the variety of microbial fermented tea, but its function regarding anti-inflammation remains unclear. In the present study, we investigated the effects of RPT on dextran sulfate sodium (DSS)-induced colitis in mice. The results demonstrated that RPT significantly relieved the loss of body weight, disease severity and shortening of colon length, and remarkably inhibited the secretion of pro-inflammatory cytokines by lessening the infiltration of inflammatory cells. Furthermore, we found that RPT suppressed the activation of the NF-κB pathway and down-regulated the expression of HIF-1α. Thus, it was concluded that RPT attenuated the progress of colitis via suppressing the HIF-1α/NF-κB signaling pathways thus reducing inflammation. This suggests that RPT may be a potential anti-inflammatory nutraceutical for the prevention and treatment of colonic colitis.

Posttranslational modifications as therapeutic targets for intestinal disorders

A variety of biological processes are regulated by posttranslational modifications. Posttranslational modifications including phosphorylation, ubiquitination, glycosylation, and proteolytic cleavage, control diverse physiological functions in the gastrointestinal tract. Therefore, a better understanding of their implications in intestinal diseases, including inflammatory bowel disease, irritable bowel syndrome, celiac disease, and colorectal cancer would provide a basis for the identification of novel biomarkers as well as attractive therapeutic targets. Posttranslational modifications can be common denominators, as well as distinct biomarkers, characterizing pathological differences of various intestinal diseases. This review provides experimental evidence that identifies changes in posttranslational modifications from patient samples, primary cells, or cell lines in intestinal disorders, and a summary of carefully selected information on the use of pharmacological modulators of protein modifications as therapeutic options.

Caesalpinia crista coat extract protects red blood cell from sodium nitrite-induced oxidative stress and exhibits antiplatelet activity

: To understand the RBC protecting efficiency and antiplatelet activity of methanolic extract of Caesalpinia crista coat (MECCC). RBC-protecting activity of MECCC was evaluated using assays, such as DPPH, level of lipid peroxidation, protein carbonyl content, superoxide dismutase and catalase as a marker of oxidative stress whereas, platelet aggregation inhibition was performed using human platelet-rich plasma (PRP). MECCC showed about 76% of DPPH-scavenging activity, with an IC50 value of 71.89 μg/ml. The MECCC reduced the level of lipid peroxidation and protein carboxylation in RBC caused by NaNO2 in a dose-dependent manner. In addition, MECCC normalized the levels of superoxide dismutase (SOD) and catalase (CAT) in oxidative stress-induced RBC in a dose-dependent manner. This suggested the protective effect of MECCC on RBC against oxidative stress. Furthermore, MECCC also exhibited mild antiplatelet activity by inhibiting both ADP and epinephrine agonists that induced platelet aggregation. The noticed inhibition percentage was found to be 28 and 23%, respectively at the concentration of 150 μg. Interestingly, MECCC did not hydrolyse the RBC suggesting its nontoxic properties. MECCC possesses protective effect of RBC against NaNO2 (10 mmol/l) induce oxidative stress and inhibits platelet aggregation.

Camellia sinensis and Litsea coreana Ameliorate Intestinal Inflammation and Modulate Gut Microbiota in Dextran Sulfate Sodium-Induced Colitis Mice

SCOPE

Polyphenol-enriched herbal extracts have been proved as alternative therapeutic strategies for experimentally induced colitis. The in vivo and in vitro anti-inflammatory effects of Camellia sinensis (green, white, yellow, oolong, black, and dark tea) and Litsea coreana (hawk tea) are comparatively explored.

METHODS AND RESULTS

HPLC analysis confirms dissimilarities among phytochemical compositions of these teas. The tea extracts (TEs) significantly decrease the production of pro-inflammatory cytokines (IL-6, IL-12, and tumor necrosis factor-α) and increase the anti-inflammatory cytokines (IL-10) in LPS-stimulated RAW 264.7 macrophages and a dextran sodium sulfate (DSS)-induced colitis mouse model. The treatment of TEs in colitis mice can ameliorate colon inflammation, pro-oxidative enzyme activity, colon integrity, and suppress the activation of nuclear factor-κB. Of note, green TE significantly attenuates the DSS-induced decrease in richness and diversity of gut microbiota. Moreover, TEs are capable of exerting a prebiotic effect on gut microbiota by increasing the abundance of potentially beneficial bacteria (e.g., Faecalibaculum, and Bifidobacterium), and decreasing the abundance of potentially harmful bacteria (e.g., Bacteroids, and Mucispirillum). TEs restore the decreased production of SCFAs in the feces of colitic mice.

CONCLUSION

The treatment of seven types of tea can alleviate DSS-induced colitis in mice, and modulate the dysbiosis of gut microbiota in colitis mice.

Effects of Guchang Capsule on Dextran Sulphate Sodium-Induced Experimental Ulcerative Colitis in Mice

Guchang capsule (GC) is a Chinese materia medica standardized product extracted from 15 Chinese traditional medical herbs and it has been clinically used in the treatment of intestinal disease. In this study, in order to extend the research of GC in intestinal disease, we were aiming to evaluate potential effects of GC on dextran sulphate sodium- (DSS-) induced murine experimental colitis and to elucidate the underlying mechanisms. GC treatment attenuated DSS-induced body weight loss and reduced the mortality. Moreover, GC treatment prevented DSS-induced colonic pathological damage; meanwhile it inhibited proinflammatory cytokines production in colon tissues. In vitro, GC significantly reduced LPS-induced proinflammatory cytokines production via inhibiting the activation of NF-κB in macrophage cells, and the expressions of several long noncoding RNAs (lncRNAs) which were reported in regulating NF-κB signaling pathway were obviously affected by adding GC into culture medium. In conclusion, our data suggested that administration of GC exhibits therapeutic effects on DSS-induced colitis partially through regulating the expression of NF-κB related lncRNAs in infiltrating immune cells.

Beneficial effects of the traditional medicine Igongsan and its constituent ergosterol on dextran sulfate sodium-induced colitis in mice

Ulcerative colitis (UC) is a type of inflammatory bowel disease and is considered a chronic gastrointestinal disorder. Igongsan (IGS) is a Korean herbal medicine, which has been used to treat digestive disorders. However, the ameliorative effect and molecular mechanisms of IGS in intestinal inflammation have not yet been studied in detail. The present study aimed to investigate the protective effects of IGS and its constituent, ergosterol, in a mouse model of dextran sulfate sodium (DSS)‑induced colitis. Colitis was induced in mice by supplementing their drinking water with 5% (w/v) DSS for 7 days. The effects of IGS were then determined on DSS‑induced clinical signs of colitis, including weight loss, colon shortening, diarrhea and obscure/gross bleeding. In addition, the effects of IGS were determined on the expression levels of inflammation‑associated genes in the colon tissue of DSS‑treated mice. The results of the present study demonstrated that mice treated with DSS exhibited marked clinical symptoms, including weight loss and reduced colon length. Treatment with IGS attenuated these symptoms and also suppressed the expression levels of tumor necrosis factor‑α and interleukin‑6, as well as the expression of cyclooxygenase‑2 in the colon tissue of DSS‑treated mice. IGS also reduced the activation of the transcription factor nuclear factor‑κB p65 in the colon tissue of DSS‑treated mice. In addition, ergosterol was shown to attenuate the DSS‑induced clinical symptoms of colitis in mice. In conclusion, the present study provided experimental evidence that IGS may be a useful therapeutic drug for patients with UC.

NF-κB and Nrf2 signaling pathways contribute to wogonin-mediated inhibition of inflammation-associated colorectal carcinogenesis

The transcriptional factors nuclear factor-κB (NF-κB) and NF-E2-related factor 2 (Nrf2) have been recently reported to have critical roles in protecting various tissues against inflammation and colitis-associated colorectal cancer (aberrant crypt foci). Our previous studies showed that wogonin (5,7-dihydroxy-8-methoxyflavone) possessed anti-neoplastic and anti-inflammatory activities. The present study extended these important earlier findings by exploring the effect of wogonin on the initiation and development of colitis-associated cancer. Wogonin lowered tumor incidence and inhibited the development of colorectal adenomas in azoxymethane- or dextran sulfate sodium-induced mice. We found that wogonin significantly decreased the secretion and expression of IL-6 and IL-1β, reduced cell proliferation and nuclear expression of NF-κB in adenomas and surrounding tissues and promoted Nrf2 nuclear translocation in surrounding tissues, although overexpressed Nrf2 in tumor tissues was independent of wogonin administration. Furthermore, wogonin inhibited the interaction between human monocytic THP-1 cells and human colon cancer HCT116 cells, and significantly downregulated lipopolysaccharide-induced secretion of prototypical pro-inflammatory cytokines IL-6 and IL-1β in THP-1 cells. Further mechanism research revealed that wogonin inhibited the nuclear translocation of NF-κB and phosphorylation of IκB and IKKα/β, and promoted Nrf2 signaling pathway in HCT116 cells and THP-1 cells. Taken together, the present results indicated that wogonin effectively suppressed inflammation-associated colon carcinogenesis and cancer development, suggesting its potential as a chemopreventive agent against colitis-associated colon cancer.

Effects of methanolic extract form Fuzhuan brick-tea on hydrogen peroxide-induced oxidative stress in human intestinal epithelial adenocarcinoma Caco-2 cells

The present study investigated the protective effect of methanolic extract from Fuzhuan brick‑tea (FME) on hydrogen peroxide (H2O2)‑induced oxidative stress in the human intestinal epithelial adenocarcinoma cell line Caco‑2. Caco‑2 cells were pretreated with different concentrations (50, 100 and 200 µg/ml) of FME for 2 h and then exposed to H2O2 (1 mM) for 6 h. FME did not exhibit a significant cytotoxic effect and increased the cell viability following H2O2 treatment by decreasing lipid peroxidation in Caco‑2 cells. To investigate the protective effect of FME on H2O2‑induced oxidative stress in Caco‑2 cells, the levels of intracellular glutathione (GSH) and the activity of the endogenous antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH‑px) and glutathione S‑transferase (GST), were determined. FME significantly increased the level of GSH and the activity of antioxidant enzymes. The results from the present study demonstrated that FME has a protective effect on H2O2‑induced oxidative damage in Caco‑2 cells through the inhibition of lipid peroxidation and the increase in the activity of antioxidant enzymes. In addition, FME reduced the H2O2‑induced expression of interleukin‑8 at both the mRNA and protein levels in Caco‑2 cells.

Protective role of andrographolide in bleomycin-induced pulmonary fibrosis in mice

Idiopathic pulmonary fibrosis (IPF) is a chronic devastating disease with poor prognosis. Multiple pathological processes, including inflammation, epithelial mesenchymal transition (EMT), apoptosis, and oxidative stress, are involved in the pathogenesis of IPF. Recent findings suggested that nuclear factor-κB (NF-κB) is constitutively activated in IPF and acts as a central regulator in the pathogenesis of IPF. The aim of our study was to reveal the value of andrographolide on bleomycin-induced inflammation and fibrosis in mice. The indicated dosages of andrographolide were administered in mice with bleomycin-induced pulmonary fibrosis. On day 21, cell counts of total cells, macrophages, neutrophils and lymphocytes, alone with TNF-α in bronchoalveolar lavage fluid (BALF) were measured. HE staining and Masson’s trichrome (MT) staining were used to observe the histological alterations of lungs. The Ashcroft score and hydroxyproline content of lungs were also measured. TGF-β1 and α-SMA mRNA and protein were analyzed. Activation of NF-κB was determined by western blotting and electrophoretic mobility shift assay (EMSA). On day 21 after bleomycin stimulation, andrographolide dose-dependently inhibited the inflammatory cells and TNF-α in BALF. Meanwhile, our data demonstrated that the Ashcroft score and hydroxyproline content of the bleomycin-stimulated lung were reduced by andrographolide administration. Furthermore, andrographloide suppressed TGF-β1 and α-SMA mRNA and protein expression in bleomycin-induced pulmonary fibrosis. Meanwhile, andrographolide significantly dose-dependently inhibited the ratio of phospho-NF-κB p65/total NF-κB p65 and NF-κB p65 DNA binding activities. Our findings indicate that andrographolide compromised bleomycin-induced pulmonary inflammation and fibrosis possibly through inactivation of NF-κB. Andrographolide holds promise as a novel drug to treat the devastating disease of pulmonary fibrosis.

Carbon monoxide attenuates dextran sulfate sodium-induced colitis via inhibition of GSK-3β signaling

Endogenous carbon monoxide (CO) is produced by heme oxygenase-1 (HO)-1 which mediates the degradation of heme into CO, iron, and biliverdin. Also, CO ameliorates the human inflammatory bowel diseases and ulcerative colitis. However, the mechanism for the effect of CO on the inflammatory bowel disease has not yet been known. In this study, we showed that CO significantly increases survival percentage, body weight, colon length as well as histologic parameters in DSS-treated mice. In addition, CO inhalation significantly decreased DSS induced pro-inflammatory cytokines by inhibition of GSK-3β in mice model. To support the in vivo observation, TNF-α, iNOS and IL-10 after CO and LiCl treatment were measured in mesenteric lymph node cells (MLNs) and bone marrow-derived macrophages (BMMs) from DSS treated mice. In addition, we determined that CO potentially inhibited GSK-3β activation and decreased TNF-α and iNOS expression by inhibition of NF-κB activation in LPS-stimulated U937 and MLN cells pretreated with CO. Together, our findings indicate that CO attenuates DSS-induced colitis via inhibition of GSK-3β signaling in vitro and in vivo. Importantly, this is the first report that investigated the molecular mechanisms mediated the novel effects of CO via inhibition GSK-3β in DSS-induced colitis model.

Review article: evidence-based dietary advice for patients with inflammatory bowel disease

BACKGROUND

The therapeutic effect of enteral nutrition in Crohn's disease (CD) and the epidemiological associations between diet and inflammatory bowel disease (IBD) implicate diet in IBD causation. There is little evidence, however, to support specific dietary changes and patients often receive contradictory advice.

AIM

To review the literature on the impacts of diet on IBD causation and activity to produce guidance based on 'best available evidence'.

METHOD

Review of Medline, Embase and Cochrane databases from 1975 to 2012 using MeSH headings 'crohn's disease' 'ulcerative colitis' 'enteral' 'diet' 'nutrition' 'fatty acid' and 'food additives'.

RESULTS

Enteral nutrition with a formula-defined feed is effective treatment for CD, but approximately 50% of patients relapse within 6 months of return to normal diet. There is no direct evidence of benefit from any other specific dietary modification in CD, but indirect evidence supports recommendation of a low intake of animal fat, insoluble fibre and processed fatty foods containing emulsifiers. Foods tolerated in sustained remission may not be tolerated following relapse. Some evidence supports vitamin D supplementation. In ulcerative colitis (UC), evidence is weaker, but high intakes of meat and margarine correlate with increased UC incidence and high meat intake also correlates with increased likelihood of relapse.

CONCLUSIONS

There is little evidence from interventional studies to support specific dietary recommendations. Nevertheless, people with IBD deserve advice based on 'best available evidence' rather than no advice at all, although dietary intake should not be inappropriately restrictive. Further interventional studies of dietary manipulation are urgently required.

Anti-inflammatory effects of Lacto-Wolfberry in a mouse model of experimental colitis

AIM: To investigate the anti-inflammatory properties of Lacto-Wolfberry (LWB), both in vitro and using a mouse model of experimental colitis.

METHODS: The effects of LWB on lipopolysaccharide (LPS)-induced reactive oxygen species (ROS) and interleukin (IL)-6 secretion were assessed in a murine macrophage cell line. in vitro assessment also included characterizing the effects of LWB on the activation of NF-E2 related 2 pathway and inhibition of tumor necrosis factor-α (TNF-α)-induced nuclear factor-κB (NF-κB) activation, utilizing reporter cell lines. Following the in vitro assessment, the anti-inflammatory efficacy of an oral intervention with LWB was tested in vivo using a preclinical model of intestinal inflammation. Multiple outcomes including body weight, intestinal histology, colonic cytokine levels and anti-oxidative measures were investigated.

RESULTS: LWB reduced the LPS-mediated induction of ROS production [+LPS vs 1% LWB + LPS, 1590 ± 188.5 relative luminescence units (RLU) vs 389 ± 5.9 RLU, P < 0.001]. LWB was more effective than wolfberry alone in reducing LPS-induced IL-6 secretion in vitro (wolfberry vs 0.5% LWB, 15% ± 7.8% vs 64% ± 5%, P < 0.001). In addition, LWB increased reporter gene expression via the anti-oxidant response element activation (wolfberry vs LWB, 73% ± 6.9% vs 148% ± 28.3%, P < 0.001) and inhibited the TNF-α-induced activation of the NF-κB pathway (milk vs LWB, 10% ± 6.7% vs 35% ± 3.3%, P < 0.05). Furthermore, oral supplementation with LWB resulted in a reduction of macroscopic (-LWB vs +LWB, 5.39 ± 0.61 vs 3.66 ± 0.59, P = 0.0445) and histological scores (-LWB vs +LWB, 5.44 ± 0.32 vs 3.66 ± 0.59, P = 0.0087) in colitic mice. These effects were associated with a significant decrease in levels of inflammatory cytokines such as IL-1β (-LWB vs +LWB, 570 ± 245 μg/L vs 89 ± 38 μg/L, P = 0.0106), keratinocyte-derived chemokine/growth regulated protein-α (-LWB vs +LWB, 184 ± 49 μg/L vs 75 ± 20 μg/L, P = 0.0244), IL-6 (-LWB vs +LWB, 318 ± 99 μg/L vs 117 ± 18 μg/L, P = 0.0315) and other pro-inflammatory proteins such as cyclooxygenase-2 (-LWB vs +LWB, 0.95 ± 0.12 AU vs 0.36 ± 0.11 AU, P = 0.0036) and phosphorylated signal transducer and activator of transcription-3 (-LWB vs +LWB, 0.51 ± 0.15 AU vs 0.1 ± 0.04 AU, P = 0.057). Moreover, antioxidant biomarkers, including expression of gene encoding for the glutathione peroxidase, in the colon and the plasma anti-oxidant capacity were significantly increased by supplementation with LWB (-LWB vs +LWB, 1.2 ± 0.21 mmol/L vs 2.1 ± 0.19 mmol/L, P = 0.0095).

CONCLUSION: These results demonstrate the anti-inflammatory properties of LWB and suggest that the underlying mechanism is at least in part due to NF-κB inhibition and improved anti-oxidative capacity.

Anti-inflammatory effect of ethanolic extract from Myagropsis myagroides on murine macrophages and mouse ear edema

BACKGROUND

This study aims to investigate anti-inflammatory effect of ethanolic extract of Myagropsis myagroides (EMM) in the lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and the phorbol 12-myristate 13-acetate (PMA)-induced ear edema in mice, and to clarify its underlying molecular mechanisms.

METHODS

The levels of nitric oxide (NO), prostaglandin E2 (PGE2), and pro-inflammatory cytokines were measured by Griess assay and enzyme linked immunosorbent assay. The expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), mitogen-activated protein kinases (MAPKs), and Akt were measured using Western blotting. Nuclear translocation and transcriptional activation of nuclear factor-κB (NF-κB) were determined by immunocytochemistry and reporter gene assay, respectively. PMA-induced mouse ear edema was used as the animal model of inflammation. Anti-inflammatory compounds in EMM were isolated using high-performance liquid chromatography and identified by nuclear magnetic resonance.

RESULTS

EMM significantly inhibited the production of NO, PGE2, and pro-inflammatory cytokines in a dose-dependent manner and suppressed the expression of iNOS and COX-2 in LPS-stimulated RAW 264.7 cells. EMM strongly suppressed nuclear translocation of NF-κB by preventing degradation of inhibitor of κB-α as well as by inhibiting phosphorylation of Akt and MAPKs. EMM reduced ear edema in PMA-induced mice. One of the anti-inflammatory compounds in EMM was identified as 6,6'-bieckol.

CONCLUSIONS

These results suggest that the anti-inflammatory properties of EMM are associated with the down-regulation of iNOS, COX-2, and pro-inflammatory cytokines through the inhibition of NF-κB pathway in LPS-stimulated macrophages.