Protective effect of sucrose esters from cape gooseberry (Physalis peruviana L.) in TNBS-induced colitis.

Phytotherapy is an attractive strategy to treat inflammatory bowel disease (IBD) that could be especially useful in developing countries. We previously demonstrated the intestinal anti-inflammatory effect of the total ethereal extract from the Physalis peruviana (Cape gooseberry) calyces in TNBS-induced colitis. This work investigates the therapeutic potential of Peruviose A and B, two sucrose esters that constitute the major metabolites of its calyces. The effect of the Peruvioses A and B mixture on TNBS-induced colitis was studied after 3 (preventive) and 15-days (therapy set-up) of colitis induction in rats. Colonic inflammation was assessed by measuring macroscopic/histologic damage, MPO activity, and biochemical changes. Additionally, LPS-stimulated RAW 264.7 macrophages were treated with test compounds to determine the effect on cytokine imbalance in these cells. Peruvioses mixture ameliorated TNBS-induced colitis in acute (preventive) or established (therapeutic) settings. Although 3-day treatment with compounds did not produce a potent effect, it was sufficient to significantly reduce the extent/severity of tissue damage and the microscopic disturbances. Beneficial effects in the therapy set-up were substantially higher and involved the inhibition of pro-inflammatory enzymes (iNOS, COX-2), cytokines (TNF-α, IL-1ß, and IL-6), as well as epithelial regeneration with restoration of goblet cells numbers and expression of MUC-2 and TFF-3. Consistently, LPS-induced RAW 264.7 cells produced less NO, PGE2, TNF-α, IL-6, and MCP-1. These effects might be related to the inhibition of the NF-κB signaling pathway. Our results suggest that sucrose esters from P. peruviana calyces, non-edible waste from fruit production, might be useful as an alternative IBD treatment.

Therapeutic effect of Yiyi Fuzi Baijiang formula on TNBS-induced ulcerative colitis via metabolism and Th17/Treg cell balance.

ETHNOPHARMACOLOGICAL RELEVANCE: Yiyi Fuzi Baijiang formula (YFB) is a traditional Chinese medicine prescription composed of Coix seed, Radix Aconiti Lateralis and Patrinia villosa, which has been used to treat ulcerative colitis (UC) for thousands of years. AIM OF THE STUDY: To investigate the therapeutic effect and metabolic analysis of YFB formula on UC in rats induced by 2,4,6-trinitro-benzene sulfonic acid (TNBS). MATERIALS AND METHODS: Six main alkaloids in the YFB formula were determined by UPLC‒MS/MS. The rat UC model was induced by TNBS, and the therapeutic effect of YFB formula on UC was evaluated by disease activity index (DAI) score and hematoxylin-eosin (HE) staining. UPLC-QTRAP-MS metabolomics technology was used to screen potential biomarkers for YFB treatment of UC in combination with multivariate data statistics and further analyze related metabolic pathways. Western blotting was used to detect the protein levels of NLRP1, NLRP3, NLRC4, ASC, pro-caspase1 and Caspase-1 in rat liver tissues. ELISA and immunohistochemistry were used to detect the contents of interleukin (IL)-17A, IL-21, IL-22, IL-6, TNF-α, IL-1ß and IL-18 in rat serum and liver tissues. RESULTS: The DAI scores of the YFB groups were significantly reduced, and colon tissue injury was significantly improved (p < 0.01). The results of metabolomics analysis revealed 29 potential biomarkers in serum and 27 potential biomarkers in liver. YFB formula can treat UC by affecting glycerophospholipid metabolism, primary bile acid biosynthesis, glyoxylic acid and dicarboxylic acid metabolism, and arginine and proline metabolism. Compared with the model group, the contents of IL-17A, IL-21, IL-22, IL-6, TNF-α, IL-1ß and IL-18 in the YFB groups were decreased in a dose-dependent manner (p < 0.01). Compared with those in the model group, the protein levels of NLRP1, NLRP3, NLRC4, ASC, pro-caspase1 and Caspase-1 in the YFB groups were significantly decreased in a dose-dependent manner (p < 0.01). CONCLUSIONS: The therapeutic effect of YFB formula on UC rats was dose dependent, and the effect of the YFB (2.046 g/kg) group was close to that of the positive group. YFB formula has an anti-inflammatory effect on UC by regulating the balance of Th17/Treg cells in rats.

Pre-clinical investigation of protective effect of nutraceutical D-glucosamine on TNBS-induced colitis.

OBJECTIVE: The level of precursors involved in the biosynthesis of glycosaminoglycan (GAG), glucosamine synthase, and N-acetyl glucosamine (NAG), are significantly reduced in inflammatory bowel disease (IBD). This results in deficient GAG content in mucosa, which eventually disrupt the gut wall integrity, provoking abnormal immunological responses. This is characterized by colossal liberation of inflammatory mediators including tumor necrosis factor-alpha (TNF-α), interleukins (ILs), and reactive oxygen species (ROS) provoking colonic inflammation. D-glucosamine (D-GLU) is reported to suppress oxidative stress, and pro-inflammatory cytokines and acts as a starting material for biosynthesis of NAG. The potential of D-GLU and its combination with mesalamine (5-ASA) was investigated in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-instigated IBD in Wistar rats. MATERIALS AND METHODS: Standard and test drugs were given orally for 5 d to separate groups of rats. Colonic inflammation was evaluated by disease activity score rate (DASR), colon/body weight ratio, colon length, diameter, colon pH, histological injury, and score. Inflammatory biomarkers IL-1ß, TNF-α, along with reduced glutathione (GSH), and malondialdehyde (MDA) were assessed. RESULTS: Combination of D-GLU + 5-ASA significantly ameliorated severity of colonic inflammation by lowering DASR (p < 0.001) and colon/body weight ratio (p < 0.001), restored the colonic architecture and suppressed the histopathological score (p < 0.001), along with the absence of major adverse reactions. The combination suppressed the levels of inflammatory markers (p < 0.001) and MDA (p < 0.001) while enhancing GSH level (p < 0.001). CONCLUSION: In comparison to individual 5-ASA and D-GLU, combination of drugs significantly diminished colitis severity through their combined anti-inflammatory and antioxidant effects by acting on multiple targets simultaneously. The combination holds remarkable potential in the management of IBD.

MFE40-the active fraction of Mume Fructus alcohol extract-alleviates Crohn's disease and its complications.

ETHNOPHARMACOLOGICAL RELEVANCE: Mume Fructus (MF) is a well-known traditional Chinese medicine used to treat chronic cough, prolonged diarrhea, and other inflammation-related diseases. We previously confirmed the anti-colitis effect of its ethanol extract on a 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced Crohn's disease (CD) rat model. However, the active ingredients and underlying mechanisms of MF remain unknown. AIM OF THE STUDY: To clarify the material basis and potential mechanism of the ethanol extract of MF (MFE) in alleviating CD and its complications, such as lung injury and intestinal obstruction. MATERIALS AND METHODS: MF was extracted with 80% ethanol aqueous solution and separated with 0, 40, and 100% ethanol aqueous solutions. MFE and its fractions were screened in a TNBS-induced CD rat model. For the bioactive fraction, the chemical composition was identified and quantified using ultrahigh-performance liquid chromatography coupled with diode-array detection and quadrupole time-of-flight tandem mass spectrometry. Interleukin (IL)-1ß, IL-6, IL-17, transforming growth factor (TGF)-ß, and lipopolysaccharide (LPS) levels in the colon, lungs, and/or plasma were detected using enzyme-linked immunosorbent assays. The expression levels of zonula occludens-1 (ZO-1) and occludin in the colon were measured using immunohistochemical staining, and the intestinal microbiota and short-chain fatty acid (SCFA) levels were analyzed using 16S rRNA gene sequencing and gas chromatography/mass spectrometry. RESULTS: The 40% ethanol fraction of MF (MFE40), which mainly contained methyl citrate, ethyl citrate, and caffeoylquinic acid ethyl esters, was identified as the active fraction that could alleviate CD in rats. MFE40 could ameliorate inflammation and fibrosis in the colon and lung tissues by inhibiting the secretion of cytokines, such as IL-1ß, IL-6, IL-17, and TGF-ß, along with intestinal obstruction and lung injury in CD rats. The possible mechanisms of MFE40 were related to increased expression of ZO-1 and occludin in the colon, reduction in plasma LPS levels, and restoration of SCFAs via reduction in the relative abundance of Adlercreutzia, Clostridium_sensu_stricto_1, Erysipelatoclostridium, Faecalibaculum, norank_f_Erysipelotrichaceae, Phascolarctobacterium Coriobacteriaceae_UGG_002, and Allobaculum and increase in the relative abundance of Escherichia shigella, Christensenella, Acetivibrio_ethanolgignens, and Butyricicoccus. MFE40 had no significant influence on the inflammatory factors in healthy rats. CONCLUSIONS: Citrate esters and hydroxycinnamate esters are the main active constituents of MFE40. MFE40 exhibited a remission effect on CD rats and inhibited intestinal obstruction and lung injury via anti-inflammatory effects and regulation of the intestinal microbiota-gut-lung homeostasis.

Protective effect of naringin ameliorates TNBS-induced colitis in rats via improving antioxidant status and pro-inflammatory cytokines.

Aim: Ulcerative colitis (UC) is a chronic inflammatory bowel disease that disturbs the colon mucosal lining and is characterized by oxido-nitrosative stress and the release of pro-inflammatory cytokines. Naringin (NG) belongs to a group of chemicals called bioflavonoids derived from grapefruit and related citrus species. NG has been widely used as folk medicine in many countries, due to its several health benefits.Method: This study examined the effect of NG on 2,4,6 trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats. Forty-two male Wistar rats were divided into seven groups like Normal Control (NC), Ethanol Control (EC), Disease Control (DC), NG 20 (20 mg/kg, p.o.), NG 40 (40 mg/kg, p.o.), NG 80 (80 mg/kg, p.o.), and Dexamethasone (DEX) (2 mg/kg, p.o.). Colitis was induced in Wistar albino rats by administering TNBS intra-rectally (in 50% ethanol). The rats were then given 14 days of NG (20, 40, and 80 mg/kg) and DEX (2 mg/kg) treatment. Several behavioral, biochemical, molecular, and histological analyses were performed.Result: The treatment of rats with NG significantly increased the body weight (p < .05, p < .01), hematological parameters like hemoglobin (p < .05, p < .01, p < .001), red blood cells (p < .01, p < .001), and platelets count (p < .01, p < .001) and decreased in spleen weight (p < .01, p < .001), colon weight (p < .01, p < .001), colon weight to length ratio (p < .05, p < .01, p < .001), macroscopic score (p < .01, p < .001), adhesion score (p < .01, p < .001), diarrhea score (p < .05, p < .001), stool consistency (p < .01, p < .001), rectal bleeding score (p < .05, p < .01, p < .001), white blood cells count (p < .01, p < .001). NG significantly (p < .01, p < .001) increased colonic superoxide, glutathione, and catalase levels and decreased malondialdehyde and myeloperoxidase levels. It also significantly (p < .01, p < .001) decreased the biochemical parameters, proinflammatory cytokines and reduced the histological damage in the colon tissue caused by TNBS.Conclusion: Our results demonstrated that NG treatment attenuated pathologic changes of TNBS-induced colitis in rats through restoring colonic damage and reducing inflammatory response in the colon tissue. Thus, NG might be considered as an effective candidate for the treatment of UC patients.

Study of the therapeutic effects of Painong powder on ulcerative colitis and the role of Platycodonis Radix in the prescription based on pharmacodynamic, pharmacokinetic, and tissue distribution analyses.

ETHNOPHARMACOLOGICAL RELEVANCE: Herbal formulas have unique efficacy and are of great significance to the theory and practice of Chinese medicine and are therefore gaining increasing attention in research. Painong powder (PNS), composed of Aurantii fructus immaturus (Zhishi in Chinese, ZS), Paeoniae Radix Alba (Baishao in Chinese, BS), and Platycodonis Radix (Jiegeng in Chinese, JG), has remarkable effects on the detoxification and discharge of pus. JG is traditionally used to treat pulmonary carbuncles and is considered a 'medicinal guide'. According to the composition theory of prescriptions, JG is an 'assistant and guide' medicine. The role of JG as an adjuvant has gained increasing attention. AIM OF THE STUDY: The study was designed to prove the efficacy of PNS in ulcerative colitis (UC) and to study the role of JG in PNS via pharmacodynamic, pharmacokinetic, and tissue distribution analyses. MATERIALS AND METHODS: For the pharmacodynamic study, the UC rat model was induced using 5% trinitrobenzene sulfonic acid (TNBS). The results of the macroscopic characterization, histological analysis, and cytokine levels, including those of tumour necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and nuclear factor-kappa B (NF-κB), were integrated to evaluate the treatment of UC with PNS. In addition, an LC-MS/MS method was established and validated to analyze the blood pharmacokinetic parameters and tissue distribution of naringin and paeoniflorin. RESULTS: After the administration of high-dose PNS, the UC rats showed amelioration of macroscopic damage at the lesion site. The cytokine levels in the plasma, colon, and lung tissues were also decreased. The pharmacokinetic parameters showed that compared with UC rats administered with PNS-JG, those administered with PNS showed an increase in the AUC, MRT, and Tmax of naringin and paeoniflorin, and a decrease in their clearance rate. Furthermore, naringin and paeoniflorin had higher concentrations in the colon and lung tissues in the normal and model groups administered with PNS than in those administered with PNS-JG. CONCLUSIONS: PNS was shown to have marked therapeutic efficacy against TNBS-induced UC in rats. The effect of JG in PNS was reflected by the differences in the pharmacokinetic parameters and tissue distribution of the active components, providing valuable information for the clinical application of PNS in the treatment of UC. However, knowledge about how JG works as an adjuvant medicine in PNS is still lacking.

Olaparib: A Clinically Applied PARP Inhibitor Protects from Experimental Crohn's Disease and Maintains Barrier Integrity by Improving Bioenergetics through Rescuing Glycolysis in Colonic Epithelial Cells.

Crohn's disease (CD) is an inflammatory disorder of the intestines characterized by epithelial barrier dysfunction and mucosal damage. The activity of poly(ADP-ribose) polymerase-1 (PARP-1) is deeply involved in the pathomechanism of inflammation since it leads to energy depletion and mitochondrial failure in cells. Focusing on the epithelial barrier integrity and bioenergetics of epithelial cells, we investigated whether the clinically applied PARP inhibitor olaparib might improve experimental CD. We used the oral PARP inhibitor olaparib in the 2,4,6-trinitrobenzene sulfonic acid- (TNBS-) induced mouse colitis model. Inflammatory scoring, cytokine levels, colon histology, hematological analysis, and intestinal permeability were studied. Caco-2 monolayer culture was utilized as an epithelial barrier model, on which we used qPCR and light microscopy imaging, and measured impedance-based barrier integrity, FITC-dextran permeability, apoptosis, mitochondrial oxygen consumption rate, and extracellular acidification rate. Olaparib reduced the inflammation score, the concentration of IL-1ß and IL-6, enhanced the level of IL-10, and decreased the intestinal permeability in TNBS-colitis. Blood cell ratios, such as lymphocyte to monocyte ratio, platelet to lymphocyte ratio, and neutrophil to lymphocyte ratio were improved. In H2O2-treated Caco-2 monolayer, olaparib decreased morphological changes, barrier permeability, and preserved barrier integrity. In oxidative stress, olaparib enhanced glycolysis (extracellular acidification rate), and it improved mitochondrial function (mitochondrial coupling efficiency, maximal respiration, and spare respiratory capacity) in epithelial cells. Olaparib, a PARP inhibitor used in human cancer therapy, improved experimental CD and protected intestinal barrier integrity by preventing its energetic collapse; therefore, it could be repurposed for the therapy of Crohn's disease.

Protective effect of sarsasapogenin in TNBS induced ulcerative colitis in rats associated with downregulation of pro-inflammatory mediators and oxidative stress.

BACKGROUND: Ulcerative colitis (UC) is a chronic inflammatory bowel condition considered by oxido-nitrosative stress and the release of pro-inflammatory cytokines that affects the mucosal lining of the colon. Sarsasapogenin (SG), as an active component, has been found in many plants, and it exhibits potential protective effects, such as anti-inflammatory, antioxidant, anti-psoriasis, anti-arthritis, anti-asthma, anti-depressant and anti-cancer. However, the effects of SG on UC remain unknown. OBJECTIVE: The purpose of this study was to investigate the effects of SG on 2, 4, 6-trinitrobenzene sulfonic acid (TNBS)-induced UC in rats. METHOD: Thirty Wistar rats were randomized into five groups: (i) Normal control, (ii) Disease control (TNBS), (iii) Sarsasapogenin (SG) (50 µg/rat), (iv) Fluticasone (FC) (50 µg/rat), (v) Sarsasapogenin + Fluticasone (SG + FC) (25 µg/rat). UC was induced in rats by trans-rectal instillation of TNBS (10 mg/kg). SG, FC and SG + FC were administered for 11 days and on the 8th day colitis was induced. Several molecular, biochemical and histological alterations were evaluated in the colon tissue. All treatment group results were compared to the TNBS group results. RESULT: The study results revealed that treatment of rats with SG and SG + FC combination significantly decreased the colon weight/length ratio, macroscopic inflammation score, lesions score, diarrhea score and adhesion score. Combination treatment in rats significantly reduced the production of biochemical parameters, proinflammatory cytokines, haematological parameters, serum IgE levels and restored the oxidative stress markers. SG and SG + FC treatment also considerably restored the histopathological changes induced by TNBS. CONCLUSION: Thus, SG and SG + FC combination could alter the disease progression and could be a hopeful therapeutic target for the management of UC by reducing its dose in combination with FC to elude the long term adverse effects of FC.

Atractylenolide III Ameliorates TNBS-Induced Intestinal Inflammation in Mice by Reducing Oxidative Stress and Regulating Intestinal Flora.

The present study aimed to explore the therapeutic effects of the main active ingredients of Atractylodes macrocephala on the 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced mouse colitis model. TNBS-induced colitis was established in mice, which were treated with 8-ß-Hydroxyasterolide (Atractylenolide III) for 14 days. The body weight of the mice in the middle and high dose groups of Atractylenolide III was increased compared with that of the model group. The disease activity index score was significantly reduced. The activity levels of myeloperoxidase were significantly decreased following increase in the dosage of Atractylenolide III, as determined by histological analysis. Moreover, Atractylenolide III downregulated the expression levels of the inflammatory factors interleukin-1ß and tumor necrosis factor-α, and greatly suppressed the levels of the pro-oxidant markers, reactive oxygen species and malondialdehyde, while enhancing the expression levels of the antioxidant enzymes catalase, superoxide dismutase and glutathione peroxidase. The protein expression levels of formyl peptide receptor 1 (FPR1) and nuclear respiratory factor 2 (Nrf2) were upregulated in the colonic tissues of TNBS-treated mice. This effect was effectively reversed by Atractylenolide III treatment. In vivo studies indicated that TNBS alone induced a decrease in the abundance of lactobacilli and in the biodiversity of the colon. In conclusion, the present study suggested that Atractylenolide III attenuated TNBS-induced acute colitis by regulating oxidative stress via the FPR1 and Nrf2 pathways and by affecting the development of intestinal flora.

A New Rat Model of Pouchitis After Proctocolectomy and Ileal Pouch-Anal Anastomosis Using 2,4,6-Trinitrobenzene Sulfonic Acid.

BACKGROUND: Pouchitis is a common complication after ileal pouch-anal anastomosis (IPAA) in patients with ulcerative colitis. However, an ideal model remains lacking. Therefore, we aimed to establish an appropriate model resembling human pouchitis. METHODS: Sprague-Dawley rats were randomly assigned to five groups: TNBS group, DSS group, NS group (following IPAA procedure, administrated with TNBS enema, DSS orally, normal saline enema, respectively), NI group (underwent IPAA), and sham group (underwent switch abdominal surgery). General status, weight change, hematochezia, and fecal scores were recorded. Fecal microbiota were counted under a microscope and analyzed by 16S rRNA gene high-throughput sequencing. Specimens of ileal pouch and small intestine (proximal, mid, distal) were collected to evaluate myeloperoxidase and occludin expression by immunohistochemistry and mRNA expression of pro-inflammatory markers by PCR. RESULTS: General status, hematochezia, fecal score, and increased mRNA expression of interleukin-6 and TNF-α in the TNBS group were similar to those in the DSS group, whereas the TNBS-induced model displayed a more stable weight change and more serious dysbacteriosis, not only was fecal bacterial diversity reduced, the dominant microbiota was altered. Histopathology scores of the distal small intestine in the TNBS group were lower compared with those in the DSS group (P < 0.05). A significant difference in myeloperoxidase and occludin expression in the small intestine was also detected between the TNBS and DSS groups. CONCLUSIONS: Our model mimicked the characteristics of human pouchitis and avoided potential side effects in the small intestine, and thus could be employed for further research.

Jiaolong capsule protects SD rats against 2,4,6-trinitrobenzene sulfonic acid induced colitis.

ETHNOPHARMACOLOGICAL RELEVANCE: Jiaolong capsule (JLC) was approved for the therapy of gastrointestinal diseases by the State Food and Drug Administration (SFDA) of China. It has a satisfactory curative effect in the treatment of patients with inflammatory bowel disease, however, the mechanism remains to be elucidated. AIM OF THE STUDY: In current study, the effects and possible mechanisms of JLC on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis were investigated. MATERIALS AND METHODS: Sulfasalazine and JLC were administrated orally and initialized 6 h after TNBS enema, once a day for seven consecutive days. The effect of JLC on intestinal microbial populations and LPS/TLR-4/NF-κB pathway was observed and assessed. Thirty female SD rats were distributed into six groups randomly and equally, namely, control, TNBS, TNBS + sulfasalazine (625 mg/kg), and TNBS + three different doses of JLC (25, 50, and 100 mg/kg) groups. RESULTS: The effect of JLC on restoring normal structures of colorectum and repairing colonic damage were superior to that of sulfasalazine. JLC showed a positive effect in re-balancing intestinal bacteria population of colitis, and suppressed the activation of LPS/TLR-4/NF-κB pathway. CONCLUSION: The results suggest that JLC demonstrated a beneficial effect on treating colitis in a rat model. The possible mechanisms may be through the regulatory effect of intestinal commensal bacteria and down-regulation of LPS/TLR-4/NF-κB pathway.

Dilodendron bipinnatum Radlk. extract alleviates ulcerative colitis induced by TNBS in rats by reducing inflammatory cell infiltration, TNF-α and IL-1ß concentrations, IL-17 and COX-2 expressions, supporting mucus production and promotes an antioxidant effect.

ETHNOPHARMACOLOGICAL RELEVANCE: Dilodendron bipinnatum (Sapindaceae) stem bark decoction and macerate were used to treat uterine inflammation, pain in general, dermatitis and bone fractures. These homemade preparations also have diuretic, stimulant, expectorants and sedative effects and are effective in treating worm infections in the Brazilian Pantanal population. Our previous research confirmed the anti-inflammatory activity of the hydroethanolic extract of inner stem bark of D. bipinnatum (HEDb). AIM: This work aimed to investigate the efficacy of HEDb in ameliorating experimental colitis in rats and to elucidate the possible mechanisms involved in the anti-ulcerative colitis properties of HEDb in rats and Caco-2 cell line. MATERIALS AND METHODS: The effects on cell viability, IL-8 and TNF-α in human colon adenocarcinoma (Caco-2) were determined by flow cytometer and ELISA. Wistar rats (n = 6-7) were orally gavaged with, vehicle (0.9% saline), HEDb at doses of 20, 100 or 500 mg/kg, or mesalazine at a dose of 500 mg/kg, at 48, 24 and 1 h prior to the administration of trinitrobenzene sulfonic acid via rectal administration to induce colitis. The anti-inflammatory effects of HEDb were assessed macroscopically, by myeloperoxidase (MPO) activity and for glutathione (GSH) concentration in the colon. Additionally, colonic histopathological analyses of UC severity were conducted by different staining methods (H&E, PAS and toluidine blue). Pro-inflammatory cytokines TNF-α and IL-1ß were quantified in colonic tissue by ELISA and colonic expressions of COX-2 and IL-17 were analyzed by western blotting. RESULTS: HEDb was shown to be non-cytotoxic with mean viability of 80% in Caco-2 cells. HEDb pre-treatments of 1, 5 or 20 µg/mL significantly reduced TNF-α production in Caco-2 cells by 21.8% (p < 0.05), 60.5 and 82.1% (p < 0.001) respectively following LPS treatment compared to LPS alone. However, no change in IL-8 production was observed. HEDb pre-treatment of rats subjected to TNBS significantly (p < 0.001) reduced colonic lesion score. Higher doses (100 and 500 mg/kg) caused a sharp downregulation of haemorrhagic damage, leukocyte infiltration, edema and restoration of mucus production. Moreover, mast cell degranulation was inhibited. Colonic MPO activity was reduced following all doses of HEDb, reaching 51.1% ± 1.51 (p < 0.05) with the highest dose. GSH concentration was restored by 58% and 70% following 100 and 500 mg/kg of HEDb, respectively. The oral treatment of HEDb at doses 20, 100 and 500 mg/kg decreased the concentrations of TNF-α and IL-1ß at all doses in comparison to vehicle treated control. In addition, HEDb inhibited the COX-2 and IL-17 expressions with maximal effect at 500 mg/kg (60.3% and 65% respectively; p < 0.001). In all trials, the effect of HEDb at all doses being 20, 100 and 500 mg/kg was statistically comparable to mesalazine (500 mg/kg). CONCLUSIONS: HEDb reduces colonic damage in the TNBS colitis model and relieves oxidative and inflammatory events, at least in part, by increasing mucus production, reducing leukocyte migration and reducing TNF-α (in vivo and in vitro), IL-1ß, IL-17 and COX-2 expression. Therefore, HEDb requires further investigation as a candidate for treating IBD.

Sacral nerve stimulation ameliorates colonic barrier functions in a rodent model of colitis.

BACKGROUND: The mucosal barrier damage is recognized as one of the key factors in the pathogenesis of colitis. While sacral nerve stimulation (SNS) was reported to have therapeutic potential for colitis, its mechanisms of actions on colonic permeability remained largely unknown. METHODS: In this study, colitis was induced by intrarectal administration of TNBS in rats. Five days later, they were treated with SNS or sham-SNS for 10 days. The effects of SNS on colonic permeability were assessed by measuring the expression of tight-junction proteins involved in regulating permeability and the FITC-dextran test. The mechanism of actions of SNS was investigated by studying the function of the enteric nervous system (ENS) cells and analyzing the autonomic nervous system. KEY RESULTS: SNS decreased the disease activity index, microscopic and macroscopic scores, myeloperoxidase activity, and pro-inflammatory cytokines (TNF-α, IL-6). SNS increased the expression of Zonula Occludens-1, Occludin, Claudin-1, and Junctional adhesion molecule-A in the colon tissue. The FITC-dextran test showed that the colonic permeability was lower with SCS than sham-SNS. SNS increased ChAT, pancreatic polypeptide, and GDNF and reduced norepinephrine NGF, sub-P, and mast cell overactivation in the colon tissue. Concurrently, SNS increased acetylcholine in colon tissues and elevated vagal efferent activity. CONCLUSIONS & INFERENCES: SNS ameliorates colonic inflammation and enhances colonic barrier function with the proposed mechanisms involving the increase in parasympathetic activity and modulation of the activity of the ENS and immune system, including mast cells.

Flos lonicerae flavonoids attenuate experimental ulcerative colitis in rats via suppression of NF-κB signaling pathway.

This study sought to isolate active Flos lonicerae flavonoids and evaluate their anti-oxidative and anti-inflammatory effects as well as investigate the molecular mechanistic action of these flavonoids in the rat model of ulcerative colitis (UC). Total flavonoids and three flavonoids (hyperoside, lonicerin, and luteolin) were isolated from honeysuckle and purified via column purification. Rat model of UC was established via 2,4,6-trinitrobenzene sulfonic acid (TNBS) intoxication. The anti-oxidative and anti-inflammatory effects of the three flavonoids against TNBS-induced UC were evaluated by measuring appropriate biomarkers via assay kit. The effects of hyperoside, lonicerin, and luteolin on the regulation of nuclear factor-kappa B (NF-κB) pathway were investigated using Western blot (WB) and real-time polymerase chain reaction (RT-PCR) while their protective effects on UC were also elucidated. Pretreatment with flavonoids (hyperoside, lonicerin, and luteolin at 25-100 mg/kg) and sulfasalazine (SSZ, positive control at 100 mg/kg) substantially attenuated TBNS-induced UC. Also, the flavonoids significantly reduced the levels of respective serum oxidative and proinflammatory markers such as superoxide dismutase (SOD), myeloperoxidase (MPO), malondialdehyde (MDA), prostaglandins E2 (PGE2), tumor necrosis factor-alpha (TNF-α), interleukin-beta (IL-ß), and C-reactive protein (CRP). In addition, the flavonoids remarkably inhibited the expression of NF-κB signaling pathway. F. lonicerae flavonoids (hyperoside, lonicerin, and luteolin) demonstrated potent anti-UC activities in TBNS-induced UC rat model via anti-oxidative and anti-inflammatory effects through the inhibition of NF-κB signaling pathway.

Anti-Inflammatory Local Effect of Hydroxytyrosol Combined with Pectin-Alginate and Olive Oil on Trinitrobenzene Sulfonic Acid-Induced Colitis in Wistar Rats.

Purpose: Evaluate the efficacy of hydroxytyrosol in the local treatment of inflammatory colitis. Currently, the existing treatments for inflammatory bowel diseases does not cure the disease and it is associated with high rates of side effects and complications. Hydroxytyrosol is a phenyl-ethyl-alcohol derived from the hydrolysis of oleuropein and present in olive oil, previous studies have demonstrated the anti-inflammatory effect of dietary hydroxytyrosol supplement, with no toxicity. Materials & Methods: Colitis has been induced by using Trinitrobenzene Sulfonic Acid at 40 rats. They were divided into four groups randomly: 10 rats without treatment; 10 rats with pectin/alginate mixture; 10 rats treated with pectin/alginate + olive oil; 10 rats treated with pectin/alginate + olive oil + hydroxytyrosol. Animals were sacrificed 10 days after induction of trinitrobenzene sulfonic acid, receiving 5 days of continuous treatment. Samples of the rectal area were studied and observed under a microscope to determine the damage by Hunter scoring modified, assessing inflammatory infiltration, number of intestinal walls involved, damage to the mucosal architecture, and edema. Results: When the rectum was analyzed in a global way, nonsignificant differences were observed; however, when performing an individualized analysis, statistically significant differences in the inflammatory infiltrate are present in the samples, which were evaluated using the ANOVA and Student-T statistics. Conclusions: Local treatment with the natural antioxidant hydroxytyrosol combined with pectin/alginate and olive oil of inflammatory bowel disease has been shown to be effective against inflammatory infiltration of TNBS-induced colitis.

Inactive Rhomboid Protein 2 Mediates Intestinal Inflammation by Releasing Tumor Necrosis Factor-α.

BACKGROUND: Tumor necrosis factor (TNF)-α is a major proinflammatory cytokine that plays a key role in inflammatory bowel disease (IBD). Inactive rhomboid protein 2 (iRhom2) is essential for activating TNF-α-converting enzyme (TACE) in immune cells, which regulates TNF-α release. The aim of the study was to investigate the role of iRhom2 in intestinal inflammation in IBD. METHODS: The expression of iRhom2 and TACE in lipopolysaccharide (LPS)-stimulated COLO 205 and RAW 264.7 cells was assessed by reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis. The expression of iRhom2 and TACE in the colonic tissue of IBD patients and 2,4,6-trinitrobenzenesulfonic acid solution (TNBS)-treated mice was determined by RT-PCR and immunohistochemistry. To assess the role of iRhom2 in intestinal inflammation, colitis was induced in wild-type and iRhom2-/- mice by the administration of TNBS enema. RESULTS: In LPS-stimulated COLO 205 and RAW 264.7 cells, the mRNA and protein levels of TACE and iRhom2 were upregulated. The expression of TACE and iRhom2 in the colon of the IBD patients and TNBS-treated mice was significantly enhanced. The inflammatory cells that expressed high levels of iRhom2 in the colon were identified as macrophages. Finally, iRhom2 deficiency ameliorated TNBS-induced colitis by inhibiting TNF-α release. CONCLUSIONS: iRhom2 has an important role in intestinal inflammation through TNF-α secretion in immune cells, which suggests that iRhom2 could be a novel therapeutic target for IBD.

Beneficial effects of nutritional supplements on intestinal epithelial barrier functions in experimental colitis models in vivo.

Acute and chronic colitis affect a huge proportion of the population world-wide. The etiology of colitis cases can be manifold, and diet can significantly affect onset and outcome of colitis. While many forms of acute colitis are easily treatable, chronic forms of colitis such as ulcerative colitis and Crohn's disease (summarized as inflammatory bowel diseases) are multifactorial with poorly understood pathogenesis. Inflammatory bowel diseases are characterized by exacerbated immune responses causing epithelial dysfunction and bacterial translocation. There is no cure and therapies aim at reducing inflammation and restoring intestinal barrier function. Unfortunately, most drugs can have severe side effects. Changes in diet and inclusion of nutritional supplements have been extensively studied in cell culture and animal models, and some supplements have shown promising results in clinical studies. Most of these nutritional supplements including vitamins, fatty acids and phytochemicals reduce oxidative stress and inflammation and have shown beneficial effects during experimental colitis in rodents induced by dextran sulphate sodium or 2,4,6-trinitrobenzene sulfonic acid, which remain the gold standard in pre-clinical colitis research. Here, we summarize the mechanisms through which such nutritional supplements contribute to epithelial barrier stabilization.

Sacral nerve stimulation improves colonic inflammation mediated by autonomic-inflammatory cytokine mechanism in rats.

BACKGROUND: Vagal nerve stimulation (VNS) was reported to have a therapeutic potential for inflammatory bowel disease (IBD). This study was designed to determine effects and mechanisms of SNS on colonic inflammation of in rodent models of IBD and compare the difference among SNS, VNS, and SNS plus VNS. METHODS: Intestinal inflammation in rats was induced by intrarectal administration of TNBS (2,4,6-Trinitrobenzenesulfonic acid) on the first day. Five days after intrarectal TNBS, the rats were treated with sham-VNS, VNS, Sham-SNS, SNS, and SNS + VNS for 10 days. In another experiment, after 10 days of 4% DSS (dextran sodium sulfate) in drinking water, rats were treated with 10-day sham-SNS and SNS. Various inflammatory responses were assessed; mechanisms involving autonomic functions and inflammatory cytokines were investigated. KEY RESULTS: (a) VNS, SNS, and VNS + SNS significantly and equally decreased the disease activity index and macroscopic scores, and normalized colon length; (b) IL-10 was decreased by TNBS but increased with SNS, VNS, and SNS + VNS; pro-inflammatory cytokines, IL-6, IL-17A, MCP-1 and TNF-α, were increased by TNBS but decreased with SNS, VNS, and SNS + VNS (P < .05); MPO activity was decreased by SNS, VNS, and SNS + VNS; (c) SNS, VNS, and SNS + VNS remarkably increased vagal activity that was suppressed by TNBS (P < .05); (d) smilar SNS effects were noted in rats with DSS-induced colitis. CONCLUSIONS & INFERENCES: SNS presents similar anti-inflammatory effects as VNS by inhibiting pro-inflammatory cytokines and increasing anti-inflammatory cytokines via the autonomic pathway. Similar to VNS, SNS may also have a therapeutic potential for colonic inflammation.

Acute Colitis Drives Tolerance by Persistently Altering the Epithelial Barrier and Innate and Adaptive Immunity.

BACKGROUND: Inflammatory bowel disease (IBD) has a remitting and relapsing disease course; however, relatively little is understood regarding how inflammatory damage in acute colitis influences the microbiota, epithelial barrier, and immune function in subsequent colitis. METHODS: Mice were administered trinitrobenzene sulphonic acid (TNBS) via enema, and inflammation was assessed 2 days (d2) or 28 days (d28) later. Colitis was reactivated in some mice by re-treating at 28 days with TNBS and assessing 2 days later (d30). Epithelial responsiveness to secretagogues, microbiota composition, colonic infiltration, and immune activation was compared between all groups. RESULTS: At day 28, the distal colon had healed, mucosa was restored, and innate immune response had subsided, but colonic transepithelial transport (P = 0.048), regulatory T-cell (TREG) infiltration (P = 0.014), adherent microbiota composition (P = 0.0081), and responsiveness of stimulated innate immune bone marrow cells (P < 0.0001 for IL-1ß) differed relative to health. Two days after subsequent instillation of TNBS (d30 mice), the effects on inflammatory damage (P < 0.0001), paracellular permeability (P < 0.0001), and innate immune infiltration (P < 0.0001 for Ly6C+ Ly6G- macrophages) were reduced relative to d2 colitis. However, TREG infiltration was increased (P < 0.0001), and the responsiveness of stimulated T cells in the mesenteric lymph nodes shifted from pro-inflammatory at d2 to immune-suppressive at d30 (P < 0.0001 for IL-10). These effects were observed despite similar colonic microbiota composition and degradation of the mucosal layer between d2 and d30. CONCLUSIONS: Collectively, these results indicate that acute colitis chronically alters epithelial barrier function and both innate and adaptive immune responses. These effects reduce the consequences of a subsequent colitis event, warranting longitudinal studies in human IBD subjects.

Citrus aurantium L. and Its Flavonoids Regulate TNBS-Induced Inflammatory Bowel Disease through Anti-Inflammation and Suppressing Isolated Jejunum Contraction.

Inflammatory bowel disease (IBD) is a serious digestive system disease, for which the clinical therapeutic choices remain limited. Dried fruits of Citrus aurantium L. (CAL) are a traditional medicine used for regulation of the digestive system. The aim of this study was to identify the regulatory effects of CAL on IBD and to clarify the mechanism of the active compounds. In trinitrobenzene sulfonic acid-induced IBD rats, 125 to 500 mg/kg of oral CAL significantly alleviated weight loss and diarrhea, decreased colitis inflammatory cell infiltration, and inhibited pro-inflammatory cytokine production. The mechanisms of characteristic flavonoids in CAL were evaluated involving inflammation and intestine contraction aspects. Naringenin, nobiletin, and hesperetin showed anti-inflammatory effects on lipopolysaccharide-induced RAW cells. The mechanism may be related to the inhibition of the tumor necrosis factor-α (TNF-α)-induced nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway to suppress cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expressions. Naringenin and nobiletin showed inhibitory effects on isolated jejunum contraction. The mechanism of naringenin is partly related to COX, NOS, inositol triphosphate (IP3), and finally, to decreased jejunum motility. This study demonstrated that CAL, and its flavonoids' regulatory effects on IBD through anti-inflammation and inhibition of intestine muscle contraction, can provide basic information on developing new drugs or supplements against IBD based on CAL.