Dietary extra virgin olive oil polyphenols supplementation modulates DSS-induced chronic colitis in mice

PGlyRP3 concerts with PPARγ to attenuate DSS-induced colitis in mice

Nutrients may modulate immunity through their transcription factors that act on both metabolic and immunity genes. It has been shown that the transcription factor of lipid ligands PPARγ physically binds the gene promoter of the peptidoglycan recognition protein (PGlyRP3), which showed anti-inflammatory action in vitro. It is hypothesized in the present work that olive oil feeding protects against toxicity of DSS-induced colitis via activation of the lipid transcription factor PPARγ that stimulates the anti-inflammatory PGlyRP3. Results: PGlyRP3 is expressed in mouse colon and up-regulated by olive oil feeding. Olive oil reduced mortality and severity scores of DSS-induced colitis and down-regulated the proinflammatory IL-1b, IL-6 and TNFα genes. This protective effect was accompanied by up-regulation of both PPARγ and PGlyRP3. Inhibition of PPARγ by its antagonist BADGE down-regulated PGlyRP3 and abolished the anti-inflammatory effect of olive oil feeding in this DSS-induced colitis model, reflecting the pivotal role of PPARγ binding nutrition and inflammation. Activation of PGlyRP3 by its ligand peptidoglycan was not responsible for the inflammation caused by peptidoglycan, since neutralization of TLR2 attenuated this inflammatory response without affecting the peptidoglycan-induced PGlyRP3 level. Olive oil activated the IκBα and inhibited NF-κB and cox-2 gene expressions, and p65 nuclear translocation in DSS-colitis mice, reflecting the involvement of the inhibition of NF-κB signaling pathway in the anti-inflammatory olive oil - PPARγ - PGlyRP3 access. This pathway was reactivated by the PPARγ antagonist BADGE. Conclusions: Olive oil regulates by the same transcription factor (PPARγ) both lipid metabolic and immune gene (PGlyRP3) expressions, exerting the anti-inflammatory effect, and protecting against DSS-induced colitis in mice.

Hydroxytyrosol Exerts Anti-Inflammatory and Anti-Oxidant Activities in a Mouse Model of Systemic Inflammation

Hydroxytyrosol (3,4-dihydroxyphenil-ethanol, HT), the major phenol derived from olive oil consumption, has shown different anti-inflammatory and anti-oxidant activities in vitro which may explain the chronic-degenerative diseases preventive properties of olive oil. The aim of this study was to examine the ability of HT reduce inflammatory markers, Cyclooxygenase-2 (COX2) and Tumour Necrosis Factor alfa (TNF-α and oxidative stress in vivo on a mouse model of systemic inflammation. Balb/c mice were pre-treated with HT (40 and 80 mg/Kg b.w.) and then stimulated by intraperitoneal injection of lipopolysaccharide (LPS). Blood was collected to measure COX2 gene expression by qPCR and TNF-α level by ELISA kit in plasma. In addition, the total anti-oxidant power of plasma and the DNA damage were measured by FRAP test and COMET assay, respectively. LPS increased the COX2 expression, the TNF-α production and the DNA damage. HT administration prevented all LPS-induced effects and improved the anti-oxidant power of plasma. HT demonstrated in vivo anti-inflammatory and anti-oxidant abilities. The results may explain the health effects of olive oil in Mediterranean diet. HT represents an interesting molecule for the development of new nutraceuticals and functional food useful in chronic diseases prevention.

Dietary supplementation with olive mill wastewaters induces modifications on chicken jejunum epithelial cell transcriptome and modulates jejunum morphology

BACKGROUND

The Mediterranean diet is considered one of the healthier food habits and olive oil is one of its key components. Olive oil polyphenols are known to induce beneficial effects in several pathological conditions, such as inflammatory bowel disease, and to contrast the proliferation of cancer cells or hypercholesterolemia. Polyphenols are also present in waste products derived from the olive industry: olive mill wastewaters (OMWW) are rich in polyphenols and there is an increasing interest in using OMWW in animal nutrition. OMWW are attributed with positive effects in promoting chicken performance and the quality of food-derived products. However, a tissue-specific transcriptome target analysis of chickens fed with OMWW has never been attempted.

RESULTS

We explored the effect of dietary OMWW on the intestinal function in broilers. A morphological analysis of the jejunum revealed that OMWW reduced crypt depth, whereas no significant modifications were observed for villus height and the villus height/crypt depth ratio. An RNA Sequencing analysis was performed on isolated, intestinal, epithelial cells and 280 differentially expressed genes were found using a count-based approach. An enrichment analysis revealed that the majority of up regulated genes in the OMWW group were over-represented by the regulation of viral genome replication-related GO-Terms, whereas down regulated genes were mainly involved in cholesterol and lipid metabolism.

CONCLUSIONS

Our study showed how an industrial waste product can be recycled as a feed additive with a positive relapse. OMWW dietary supplementation can be a nutritional strategy to improve chicken performance and health, prevent intestinal damage, enhance innate immunity and regulate cholesterol metabolism and fat deposition.

Virgin olive oil and its phenol fraction modulate monocyte/macrophage functionality: a potential therapeutic strategy in the treatment of systemic lupus erythematosus

Monocytes and macrophages are critical effectors and regulators of inflammation and innate immune response, which appear altered in different autoimmune diseases such as systemic lupus erythematosus (SLE). Recent studies suggested that virgin olive oil (VOO) and particularly its phenol compounds might possess preventive effects on different immune-inflammatory diseases, including SLE. Here, we evaluated the effects of VOO (and sunflower oil) on lipopolysaccharide (LPS)-activated peritoneal macrophages from a model of pristane-induced SLE in BALB/c mice, as well as those of the phenol fraction (PF) from VOO on the immune-inflammatory activity and plasticity in monocytes and monocyte-derived macrophages from healthy volunteers. The release of nitrite and inflammatory cytokines was lower in LPS-treated peritoneal macrophages from pristane-SLE mice fed the VOO diet when compared with the sunflower oil diet. PF from VOO similarly decreased the secretion of nitrite and inflammatory cytokines and expression of inducible nitric oxide, PPARγ and Toll-like receptor 4 in LPS-treated human monocytes. PF from VOO also prevented the deregulation of human monocyte subset distribution by LPS and blocked the genetic signature of M1 macrophages while favouring the phenotype of M2 macrophages upon canonical polarisation of naïve human macrophages. For the first time, our study provides several lines of in vivo and in vitro evidence that VOO and PF from VOO target and counteract inflammatory pathways in the monocyte–macrophage lineage of mice with pristane-induced SLE and of healthy subjects, which is a meaningful foundation for further development and application in preclinical and clinical use of PF from VOO in patients with SLE.

Validated UPLC-MS/MS method for the quantification of dasatinib in plasma: Application to pharmacokinetic interaction studies with nutraceuticals in Wistar rats

Dasatinib (DAS) is a tyrosine kinase inhibitor (TKI) used in the treatment of chronic myeloid leukemia and in the management of ulcerative colitis (UC). Since some nutraceuticals (e.g. curcumin, olive oil, and cocoa extract) could alter the function of ABC transporters and /or CYP450 enzymes, DAS bioavailability could potentially be affected following their co-administration. This work aims at studying the possibility of PK interaction between DAS and the selected nutraceuticals in UC rats using UPLC- MS/MS. Chromatographic analysis was carried out using BEH C 18 column (Waters) with a mobile phase consisting of acetonitrile and 50% aqueous methanol, 65:35, v/v, each with 0.1% formic acid and using erlotinib (ERL) as an internal standard (IS). DAS quantitation was carried out using multiple reaction monitoring (MRM) with positive ionization of the transitions at m/z 488.03 > 400.92 (DAS), and m/z 394.29 > 278.19 (ERL). Method validation was assessed as per the FDA guidelines for bioanalytical methods for DAS determination within the concentration range 1–500 ng/mL. No significant effect on the oral bioavailability of DAS was reported with any of the studied nutraceuticals. Thus, the concomitant administration of these nutraceuticals with DAS could be considered safe with a necessity to perform more detailed clinical investigations.

Extracellular Vesicles From the Helminth Fasciola hepatica Prevent DSS-Induced Acute Ulcerative Colitis in a T-Lymphocyte Independent Mode

The complexity of the pathogenesis of inflammatory bowel disease (ulcerative colitis and Crohn's disease) has led to the quest of empirically drug therapies, combining immunosuppressant agents, biological therapy and modulators of the microbiota. Helminth parasites have been proposed as an alternative treatment of these diseases based on the hygiene hypothesis, but ethical and medical problems arise. Recent reports have proved the utility of parasite materials, mainly excretory/secretory products as therapeutic agents. The identification of extracellular vesicles on those secreted products opens a new field of investigation, since they exert potent immunomodulating effects. To assess the effect of extracellular vesicles produced by helminth parasites to treat ulcerative colitis, we have analyzed whether extracellular vesicles produced by the parasitic helminth Fasciola hepatica can prevent colitis induced by chemical agents in a mouse model. Adult parasites were cultured in vitro and secreted extracellular vesicles were purified and used for immunizing both wild type C57BL/6 and RAG1^-/- mice. Control and immunized mice groups were treated with dextran sulfate sodium 7 days after last immunization to promote experimental colitis. The severity of colitis was assessed by disease activity index and histopathological scores. Mucosal cytokine expression was evaluated by ELISA. The activation of NF-kB, COX-2, and MAPK were evaluated by immunoblotting. Administration of extracellular vesicles from F. hepatica ameliorates the pathological symptoms reducing the amount of pro-inflammatory cytokines and interfering with both MAPK and NF-kB pathways. Interestingly, the observed effects do not seem to be mediated by T-cells. Our results indicate that extracellular vesicles from parasitic helminths can modulate immune responses in dextran sulfate sodium (DSS)-induced colitis, exerting a protective effect that should be mediated by other cells distinct from B- and T-lymphocytes.

Olive oil polyphenols reduce oxysterols -induced redox imbalance and pro-inflammatory response in intestinal cells

Dietary habits may strongly influence intestinal homeostasis. Oxysterols, the oxidized products of cholesterol present in cholesterol-containing foodstuffs, have been shown to exert pro-oxidant and pro-inflammatory effects, altering intestinal epithelial layer and thus contributing to the pathogenesis of human inflammatory bowel diseases and colon cancer. Extra virgin olive oil polyphenols possess antioxidant and anti-inflammatory properties, and concentrate in the intestinal lumen, where may help in preventing intestinal diseases. In the present study we evaluated the ability of an extra virgin olive oil phenolic extract to counteract the pro-oxidant and pro-inflammatory action of a representative mixture of dietary oxysterols in the human colon adenocarcinoma cell line (Caco-2) undergoing full differentiation into enterocyte-like cells. Oxysterols treatment significantly altered differentiated Caco-2 cells redox status, leading to oxidant species production and a decrease of GSH levels, after 1 h exposure, followed by an increase of cytokines production, IL-6 and IL-8, after 24 h. Oxysterol cell treatment also induced after 48 h an increase of NO release, due to the induction of iNOS. Pretreatment with the phenolic extract counteracted oxysterols effects, at least in part by modulating one of the main pathways activated in the cellular response to the action of oxysterols, the MAPK-NF-kB pathway. We demonstrated the ability of the phenolic extract to directly modulate p38 and JNK1/2 phosphorylation and activation of NF-kB, following its inhibitor IkB phosphorylation. The phenolic extract also inhibited iNOS induction, keeping NO concentration at the control level. Our results suggest a protective effect at intestinal level of extra virgin olive oil polyphenols, able to prevent or limit redox unbalance and the onset and progression of chronic intestinal inflammation.

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Dietary oxysterols exerted pro-oxidant and pro-inflammatory effects in differentiated Caco-2 cells.

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H₂O₂ production, GSH decrease, IL-6 and IL-8 release were detected.

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NO release due to iNOS induction was higher than controls in oxysterols treated cells.

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Olive oil phenolic extract efficiently counteracted oxysterols effects.

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Phenolic extract directly modulated p38 and JNK MAPK/NF-κB signaling axis.

Methionine restriction on oxidative stress and immune response in dss-induced colitis mice

A strong correlation exists between inflammatory bowel disease (IBD) and oxidative stress involving alterations of several key signaling pathways. It is known that methionine promotes reactive oxygen species (ROS) production; we therefore hypothesize that a methionine restriction diet would reduce ROS production, inflammatory responses, and the course of IBD. We generated a murine colitis model by dextran sodium sulfate (DSS) treatment and tested the effects of the methionine restriction diet. Forty-eight mice were randomly divided into four groups of equal size, which included a control (CON) group, an MR (methionine restriction diet) group, a DSS treated group and an MR-DSS treated group. Mice in the first two groups had unrestricted access to water for one week. Mice in the two DSS-treated groups had unrestricted access to 5% DSS solution supplied in the drinking water for the same period. Mice in the CON and DSS groups were given a basal diet, whereas mice in the MR-DSS and MR groups were fed a 0.14% MR diet. We found that DSS reduced daily weight gain, suppressed antioxidant enzyme expression, increased histopathology scores and activated NF-κB and nuclear factor erythroid 2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2/Keap1) signaling. We also showed that the MR diet upregulated catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities, decreased myeloperoxidase (MPO), TNF-α and IL-1β, and reversed activation of the NF-κB signaling pathway in MR-DSS mice. Taken together, our results imply that the MR diet may be considered as an adjuvant in IBD therapeutics.

Effect of vitamin C on azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced colitis-associated early colon cancer in mice

BACKGROUND/OBJECTIVES

The objective of this study was to investigate the effects of vitamin C on inflammation, tumor development, and dysbiosis of intestinal microbiota in an azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced inflammation-associated early colon cancer mouse model.

MATERIALS/METHODS

Male BALB/c mice were injected intraperitoneally with AOM [10 mg/kg body weight (b.w)] and given two 7-d cycles of 2% DSS drinking water with a 14 d inter-cycle interval. Vitamin C (60 mg/kg b.w. and 120 mg/kg b.w.) was supplemented by gavage for 5 weeks starting 2 d after the AOM injection.

RESULTS

The vitamin C treatment suppressed inflammatory morbidity, as reflected by disease activity index (DAI) in recovery phase and inhibited shortening of the colon, and reduced histological damage. In addition, vitamin C supplementation suppressed mRNA levels of pro-inflammatory mediators and cytokines, including cyclooxygenase-2, microsomal prostaglandin E synthase-2, tumor necrosis factor-α, Interleukin (IL)-1β, and IL-6, and reduced expression of the proliferation marker, proliferating cell nuclear antigen, compared to observations of AOM/DSS animals. Although the microbial composition did not differ significantly between the groups, administration of vitamin C improved the level of inflammation-related Lactococcus and JQ084893 to control levels.

CONCLUSION

Vitamin C treatment provided moderate suppression of inflammation, proliferation, and certain inflammation-related dysbiosis in a murine model of colitis associated-early colon cancer. These findings support that vitamin C supplementation can benefit colonic health. Long-term clinical studies with various doses of vitamin C are warranted.

Extra virgin olive oil: a key functional food for prevention of immune-inflammatory diseases

Nowadays, it is clear that an unhealthy diet is one of the prime factors that contributes to the rise of inflammatory diseases and autoimmunity in the populations of both developed and developing countries. The Mediterranean diet has been associated with a reduced incidence of certain pathologies related to chronic inflammation and the immune system. Olive oil, the principal source of dietary lipids of the Mediterranean diet, possesses a high nutritional quality and a particular composition, which is especially relevant in the case of Extra Virgin Olive Oil (EVOO). EVOO is obtained from olives solely by mechanical or other physical preparation methods, under conditions that do not alter the natural composition. EVOO is described as a key bioactive food with multiple beneficial properties and it may be effective in the management of some immune-inflammatory diseases. In this review, the key research is summarised which provides evidence of the beneficial effects of EVOO and its minor components focusing on their mechanisms on immune-inflammatory diseases such as rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel disease and sclerosis.

Modulation of intestinal epithelium homeostasis by extra virgin olive oil phenolic compounds

Extra virgin olive oil polyphenols concentrate at the intestinal level and, by modulating the microbiota, oxidative status and inflammation, contribute to prevent the onset or delay the progression of inflammatory/degenerative diseases.

Hyperoside attenuates dextran sulfate sodium-induced colitis in mice possibly via activation of the Nrf2 signalling pathway

Background

Hyperoside (Hyp) is a flavonoid glycoside compound that has been demonstrated to have anti-inflammatory, anti-apoptotic and antioxidant effects. However, the impact of Hyp on inflammatory bowel disease (IBD) has not been previously explored. Thus, we evaluated the role of Hyp in dextran sodium sulfate (DSS)-induced acute colitis in mice.

Methods

We established a mouse model of experimental acute colitis by treating mice with drinking water supplemented with 3.0% DSS for 7 days. The disease activity index (DAI), colon length, histological features and colonic malondialdehyde (MDA) levels were examined using appropriate methods, and COX-2 expression was examined by immunohistochemistry. TNF-α, IL-4, IL-6, IL-10, NF-κB p65, Bcl-2, Bax, Caspase-3, nuclear factor-erythroid 2-related factor 2 (Nrf2), hemeoxygenase-1 (HO-1) and superoxide dismutase (SOD) levels in colorectal tissues were detected by RT-PCR and western blotting.

Results

Hyp significantly attenuated DSS-induced changes in the DAI as well as DSS-induced colonic shortening and histological changes. Hyp also inhibited inflammation, a change reflected by decreases in TNF-α, IL-6, COX-2 and NF-κB p65 expression and increases in IL-10 expression. Hyp suppressed increases in the levels of apoptosis-related proteins, such as Caspase-3 and Bax, but upregulated the level of the anti-apoptotic protein Bcl2. In addition, Hyp also exerted antioxidant effects. The MDA content was decreased, and the expression of Nrf2 and its downstream targets HO-1 and SOD were increased by Hyp.

Conclusions

Based on these findings, Hyp possesses the ability to attenuate colitis, possibly by mitigating colonic inflammation and apoptosis via activation of the Nrf2 signaling pathway.

Protective effect of glutamine and arginine against soybean meal-induced enteritis in the juvenile turbot (Scophthalmus maximus)

Soybean meal can induce enteritis in the distal intestine (DI) and decrease the immunity of several cultured fish species, including turbot Scophthalmus maximus. Glutamine and arginine supplementation have been used to improve immunity and intestinal morphology in fish. This study was conducted to investigate the effects of these two amino acids on the immunity and intestinal health of turbot suffering from soybean meal-induced enteritis. Turbots (initial weight 7.6 g) were fed one of three isonitrogenous and isolipidic diets for 8 weeks: SBM (control diet), with 40% soybean meal; GLN, SBM diet plus 1.5% glutamine; ARG, the SBM diet plus 1.5% arginine. Symptoms that are typical of soybean meal-induced enteritis, including swelling of the lamina propria and subepithelial mucosa and a strong infiltration of various inflammatory cells was observed in fish that fed the SBM diet. Glutamine and arginine supplementation significantly increased (1) the weight gain and feed efficiency ratio; (2) the height and vacuolization of villi and the integrity of microvilli in DI; (3) serum lysozyme activity, and the concentrations of C3, C4, and IgM. These two amino acids also significantly decreased the infiltration of leucocytes in the lamina propria and submucosa and the expression of inflammatory cytokines including il-8, tnf-α, and tgf-β. For the mucosal microbiota, arginine supplementation significantly increased microbiota community richness and diversity, and glutamine supplementation significantly increased the relative abundance of Lactobacillus and Bacillus. These results indicate that dietary glutamine and arginine improved the growth performance, feed utilization, and distal intestinal morphology, activated the innate and adaptive immune systems, changed the intestinal mucosal microbiota community, and relieved SBMIE possibly by suppression of the inflammation response.

Influence of Dimerization of Apocynin on Its Effects in Experimental Colitis

Apocynin has been widely used as an inhibitor of the nicotinamide adenine dinucleotide phosphate oxidase (NADPH-oxidase) system and shows promise as an anti-inflammatory drug. Diapocynin, the dimeric product generated by the oxidation of apocynin in the presence of myeloperoxidase (MPO), is supposed to be its active form. In this study, diapocynin has been chemically synthesized and its activity on several inflammatory mediators in LPS-stimulated RAW 264.7 macrophages and its anti-inflammatory effect on ulcerative colitis induced by dextran sodium sulfate (DSS) in mice analyzed. We found that diapocynin showed higher inhibitory activity than apocynin. The dimer reduced ROS production, TNF-α, IL-6, and IL-1β levels and inhibited iNOS and COX-2 expression as well as decreased NO and PGE₂ production induced in LPS-stimulated RAW 264.7 cells. The anti-inflammatory molecular mechanism of diapocynin was associated with the suppression of NF-κB activation. However, these results were not paralleled by in vivo studies. Oral administration of apocynin and diapocynin (100 mg/kg) three times a week exhibited similar protections against experimental inflammatory bowel disease induced by DSS; therefore, apocynin should not be considered a prodrug. However, it should be taken into account that the dimer is more potent because its dose (0.3 mmol/kg) is half that of apocynin.

Oleuropein Decreases Cyclooxygenase-2 and Interleukin-17 Expression and Attenuates Inflammatory Damage in Colonic Samples from Ulcerative Colitis Patients

Oleuropein (OLE) is the major phenolic secoiridoid of olive tree leaves, and its antioxidant and anti-inflammatory activities have been demonstrated in in vitro and in vivo animal models. The aim of this study was to investigate the activity of OLE in the colonic mucosa from patients with ulcerative colitis (UC). Biopsies obtained during colonoscopy from 14 patients with active UC were immediately placed in an organ culture chamber and challenged with lipopolysaccharide from Escherichia coli (EC-LPS) at 1 μg/mL in the presence or absence of 3 mM OLE. The expression of cyclooxygenase (COX)-2 and interleukin (IL)-17 was assessed in total protein extracts from treated colonic biopsies by Western blotting. Levels of IL-17 were also measured in culture supernatant by ELISA. A microscopic evaluation of the cultured biopsies was performed by conventional histology and immunohistochemistry. The expression of COX-2 and IL-17 were significantly lower in samples treated with OLE + EC-LPS compared with those treated with EC-LPS alone (0.80 ± 0.15 arbitrary units (a.u.) vs. 1.06 ± 0.19 a.u., p = 0.003, and 0.71 ± 0.08 a.u. vs. 1.26 ± 0.42 a.u., p = 0.03, respectively) as were the levels of IL-17 in culture supernatants of OLE + EC-LPS treated colonic samples (21.16 ± 8.64 pg/mL vs. 40.67 ± 9.24 pg/mL, p = 0.01). Histologically, OLE-treated colonic samples showed an amelioration of inflammatory damage with reduced infiltration of CD3, CD4, and CD20 cells, while CD68 numbers increased. The anti-inflammatory activity of OLE was demonstrated in colonic biopsies from UC patients. These new data support a potential role of OLE in the treatment of UC.

The phenolic fraction of extra virgin olive oil modulates the activation and the inflammatory response of T cells from patients with systemic lupus erythematosus and healthy donors

SCOPE

Systemic lupus erythematosus (SLE) is a chronic multiorgan autoimmune disease characterized by immune deregulation, which involves altered T-cell response and imbalance of cytokine production. The phenolic fraction (PE) of extra virgin olive oil (EVOO) possesses anti-inflammatory and immunomodulatory properties and exerts preventive effects in murine models of immune-inflammatory diseases, such as SLE. The present study was designed to determine the in vitro effects of the PE from EVOO on peripheral blood mononuclear cells (PBMC) from inactive patients with SLE and healthy donors.

METHODS AND RESULTS

T-cell phenotype was investigated by flow cytometry, cytokine levels were determined by ELISA, and protein expression was detected by Western blot. The PE of EVOO decreased the frequency of CD69⁺ cells and the secretion of IFN-γ, TNF-α, IL-6, IL-1β, and IL-10. Moreover, PE increased the expression of I-kappa-B-α and decreased extracellular signal regulated kinase phosphorylation on PBMC from patients with SLE and healthy donors.

CONCLUSION

PE modulates cytokine production and attenuates induced T-cell activation, probably through NF-κB signaling pathway, providing the first evidence that PE from EVOO has an anti-inflammatory and immunomodulatory role in SLE patients and it might therefore be considered as a dietary complement in SLE management.

Anti-inflammatory intestinal activity of Combretum duarteanum Cambess. in trinitrobenzene sulfonic acid colitis model

AIM

To evaluate the anti-inflammatory intestinal effect of the ethanolic extract (EtOHE) and hexane phase (HexP) obtained from the leaves of Combretum duarteanum (Cd).

METHODS

Inflammatory bowel disease was induced using trinitrobenzenesulfonic acid in acute and relapsed ulcerative colitis in rat models. Damage scores, and biochemical, histological and immunohistochemical parameters were evaluated.

RESULTS

Both Cd-EtOHE and Cd-HexP caused significant reductions in macroscopic lesion scores and ulcerative lesion areas. The vegetable samples inhibited myeloperoxidase increase, as well as pro-inflammatory cytokines TNF-α and IL-1β. Anti-inflammatory cytokine IL-10 also increased in animals treated with the tested plant samples. The anti-inflammatory intestinal effect is related to decreased expression of cyclooxygenase-2, proliferating cell nuclear antigen, and an increase in superoxide dismutase.

CONCLUSION

The data indicate anti-inflammatory intestinal activity. The effects may also involve participation of the antioxidant system and principal cytokines relating to inflammatory bowel disease.

Diet as a Trigger or Therapy for Inflammatory Bowel Diseases

The most common question asked by patients with inflammatory bowel disease (IBD) is, "Doctor, what should I eat?" Findings from epidemiology studies have indicated that diets high in animal fat and low in fruits and vegetables are the most common pattern associated with an increased risk of IBD. Low levels of vitamin D also appear to be a risk factor for IBD. In murine models, diets high in fat, especially saturated animal fats, also increase inflammation, whereas supplementation with omega 3 long-chain fatty acids protect against intestinal inflammation. Unfortunately, omega 3 supplements have not been shown to decrease the risk of relapse in patients with Crohn's disease. Dietary intervention studies have shown that enteral therapy, with defined formula diets, helps children with Crohn's disease and reduces inflammation and dysbiosis. Although fiber supplements have not been shown definitively to benefit patients with IBD, soluble fiber is the best way to generate short-chain fatty acids such as butyrate, which has anti-inflammatory effects. Addition of vitamin D and curcumin has been shown to increase the efficacy of IBD therapy. There is compelling evidence from animal models that emulsifiers in processed foods increase risk for IBD. We discuss current knowledge about popular diets, including the specific carbohydrate diet and diet low in fermentable oligo-, di-, and monosaccharides and polyols. We present findings from clinical and basic science studies to help gastroenterologists navigate diet as it relates to the management of IBD.

Hydrogen sulfide from a NaHS source attenuates dextran sulfate sodium (DSS)-induced inflammation via inhibiting nuclear factor-κB

This study investigated the alleviating effects of hydrogen sulfide (H2S), derived from sodium hydrosulfide (NaHS), on inflammation induced by dextran sulfate sodium (DSS) in both in vivo and in vitro models. We found that NaHS injection markedly decreased rectal bleeding, diarrhea, and histological injury in DSS-challenged mice. NaHS (20 μmol/L) reversed DSS-induced inhibition in cell viability in Caco-2 cells and alleviated pro-inflammation cytokine expression in vivo and in vitro, indicating an anti-inflammatory function for H2S. It was also found that H2S may regulate cytokine expression by inhibiting the nuclear factor-κB (NF-κB) signaling pathway. In conclusion, our results demonstrated that H2S alleviated DSS-induced inflammation in vivo and in vitro and that the signal mechanism might be associated with the NF-κB signaling pathway.

Human Intervention Study to Assess the Effects of Supplementation with Olive Leaf Extract on Peripheral Blood Mononuclear Cell Gene Expression

Olive leaf extract (OLE) has been used for many years for its putative health benefits, but, to date, scientific evidence for the basis of these effects has been weak. Although recent literature has described a link between ailments such as cardiovascular disease, diabetes and cancer and a protective effect of polyphenols in the OLE, the mode of action is still unclear. Here, we describe a double-blinded placebo (PBO)-controlled trial, in which gene expression profiles of peripheral blood mononuclear cells from healthy male volunteers (n = 29) were analysed to identify genes that responded to OLE, following an eight-week intervention with 20 mL daily consumption of either OLE or PBO. Differences between groups were determined using an adjusted linear model. Subsequent analyses indicated downregulation of genes important in inflammatory pathways, lipid metabolism and cancer as a result of OLE consumption. Gene expression was verified by real-time PCR for three genes (EGR1, COX-2 and ID3). The results presented here suggest that OLE consumption may result in health benefits through influencing the expression of genes in inflammatory and metabolic pathways. Future studies with a larger study group, including male and female participants, looking into direct effects of OLE on lipid metabolism and inflammation are warranted.

Sasa quelpaertensis leaf extract regulates microbial dysbiosis by modulating the composition and diversity of the microbiota in dextran sulfate sodium-induced colitis mice

Background

Inflammatory bowel diseases (IBD) are related to a dysfunction of the mucosal immune system and they result from complex interactions between genetics and environmental factors, including lifestyle, diet, and the gut microbiome. Therefore, the effect of Sasa quelpaertensis leaf extract (SQE) on gut microbiota in a dextran sulfate sodium (DSS)-induced colitis mouse model was investigated with pyrosequencing of fecal samples.

Methods

Three groups of animals were examined: i) a control group, ii) a group that was received 2.5% DSS in their drinking water for 7 days, followed by 7 days of untreated water, and then another 7 days of 2.5% DSS in their drinking water, and iii) a group that was presupplemented with SQE (300 mg/kg body weight) by gavage for two weeks prior to the same DSS treatment schedule described in ii.

Results

SQE supplementation alleviated disease activity scores and shortened colon length compared to the other two groups. In the DSS group, the proportion of Bacteroidetes increased, whereas that the proportion of Firmicutes was decreased compared to the control group. SQE supplementation recovered the proportions of Firmicutes and Bacteroidetes back to control levels. Moreover, the diversity of microbiota in the SQE supplementation group higher than that of the DSS group.

Conclusion

SQE was found to protect mice from microbial dysbiosis associated with colitis by modulating the microbial composition and diversity of the microbiota present. These results provide valuable insight into microbiota-food component interactions in IBD.

UII/GPR14 is involved in NF-κB-mediated colonic inflammation in vivo and in vitro

The present study was conducted to investigate the molecular mechanism of urotensin II (UII) and its receptor, G protein‑coupled receptor 14 (GPR14), in colonic inflammation. Urantide, a special antagonist of GPR14, and GPR14-siRNA were used to inhibit GPR14 signaling in dextran sulfate sodium (DSS)‑induced inflammation in mice and Caco-2 cells. The results showed that urantide alleviated rectal bleeding, histological injury and production of interleukin (IL)-17 and tumor necrosis factor‑α (TNF‑α) caused by DSS in mice. GPR14-siRNA transfection subsequent with GPR14 inhibition reduced DSS-induced interferon-γ (IFN)-γ production in Caco-2 cells. Meanwhile, both in vivo and in vitro data demonstrated that inhibition of UII/GPR14 alleviated nuclear factor-κB (NF-κB) activation caused by DSS. In conclusion, UII/GPR14 signaling was involved in the DSS-induced colonic inflammation and its inhibition may serve as a potential therapeutic target, which may be associated with the NF-κB signaling pathway.

An extra-virgin olive oil rich in polyphenolic compounds has antioxidant effects in meat-type broiler chickens

The aim of this study was to extend the knowledge on the antioxidant effect of extra-virgin olive oil (EVOO) in the liver of broiler chickens not subjected to any form of insult. A total of 120 male broiler chickens (Hubbard strain) were divided into three groups and fed ad libitum with three isoenergetic diets from hatching until slaughter age (49 days) on a completely randomized design. The dietary treatments consisted of 2.5% added oil or fat from three sources as follows: diet containing sunflower oil (SFO); diet containing lard (LRD), and diet containing extra-virgin olive oil (EVOO). The activity of the main antioxidative enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GS-Px) and glutathione S-transferase (GST), and lipid peroxidation as thiobarbituric acid-reactive substances (TBARS) content, was measured in the liver of chickens. The susceptibility to undergo lipid peroxidation was assessed by exposing liver homogenate to 30 °C or to an ascorbate/iron mixture as pro-oxidant system. Dietary oil or fat type improved significantly (P < 0.05) the body weight and gain as well as feed efficiency in birds fed EVOO compared to those fed with the other treatments. Supplementing EVOO in the diet significantly (P < 0.05) reduced lipid peroxidation by increasing antioxidant defense system. These findings, besides adding more results on the antioxidant effect of extra-virgin olive oil on liver of other experimental model other than rats and humans, could be significant for animal welfare, with consequent benefits for both producers and consumers.

A review of the efficacy of dietary polyphenols in experimental models of inflammatory bowel diseases

Crohn's disease and ulcerative colitis presently have no cure and are treated with anti-inflammatory drugs or monoclonal antibodies targeting pro-inflammatory cytokines. A variety of rodent models have been used to model chronic and acute colitis. Dietary polyphenols in foods and botanicals are of considerable interest for prevention and treatment of colitis. Many dietary polyphenols have been utilized for prevention of colitis in rodent models. Berries, green tea polyphenols, curcumin, and stilbenes have been the most extensively tested polyphenols in rodent models of colitis. The majority of polyphenols tested have inhibited colitis in rodents, but increasing doses of EGCG and green tea, isoflavones, flaxseed, and α-mangostin have exacerbated colitis. Few studies have examined combination of polyphenols or other bioactives for inhibition of colitis. Translating polyphenol doses used in rodent models of colitis to human equivalent doses reveals that supplemental doses are most likely required to inhibit colitis from a single polyphenol treatment. The ability to translate polyphenol treatments in rodent models is likely to be limited by species differences in xenobiotic metabolism and microbiota. Given these limitations, data from polyphenols in rodent models suggests merit for pursuing additional clinical studies for prevention of colitis.

An update on dietary phenolic compounds in the prevention and management of rheumatoid arthritis

Certain nutritional components influence the cellular metabolism and interfere in the pathological inflammatory process, so that they may act as a coadjuvant in the treatment of many chronic inflammatory diseases, including rheumatoid arthritis (RA).

Dietary extra virgin olive oil attenuates kidney injury in pristane-induced SLE model via activation of HO-1/Nrf-2 antioxidant pathway and suppression of JAK/STAT, NF-κB and MAPK activation

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by a widespread organ involvement. Recent studies have suggested that extra virgin olive oil (EVOO) might possess preventive effects on this immunoinflammation-related disease. However, its role in SLE remained unknown. In this work, we evaluated the effects of EVOO diet in a pristane-induced SLE model in mice. Three-month-old mice received an injection of pristane or saline solution and were fed with different experimental diets: sunflower oil diet or EVOO diet. After 24weeks, mice were sacrificed, spleens were collected and kidneys were removed for immunoinflammatory detections. The kidney expression of microsomal prostaglandin E synthase 1, heme oxygenase 1 (HO-1), nuclear factor E2-related factor 2 (Nrf-2), mitogen-activated protein kinases (MAPKs), Janus kinase/signal transducer and activator of transcription (JAK/STAT) and nuclear transcription factor-kappa B (NF-κB) pathways were studied by western blotting. In addition to macroscopic and histological analyses, serum matrix metalloproteinase 3 (MMP-3) levels and proinflammatory cytokines production in splenocytes were evaluated by enzyme-linked immunoassay. We have demonstrated that EVOO diet significantly reduced renal damage and decreased MMP-3 serum and PGE2 kidney levels as well as the proinflammatory cytokines production in splenocytes. Our data indicate that Nrf-2 and HO-1 protein expressions were up-regulated in those mice fed with EVOO and the activation of JAK/STAT, MAPK and NF-κB pathways were drastically ameliorated. These results support the interest of EVOO as a beneficial functional food exerting a preventive/palliative role in the management of SLE.

Preventive and therapeutic effects of blueberry (Vaccinium corymbosum) extract against DSS-induced ulcerative colitis by regulation of antioxidant and inflammatory mediators

Inflammatory bowel disease (IBD) is an inflammatory disorder caused by hyperactivation of effector immune cells that produce high levels of proinflammatory cytokines. The aims of our study were to determine whether orally administered blueberry extract (BE) could attenuate or prevent the development of experimental colitis in mice and to elucidate the mechanism of action. Female Balb/C mice (n=7) were randomized into groups differing in treatment conditions (prevention and treatment) and dose of BE (50 mg/kg body weight). Acute ulcerative colitis was induced by oral administration of 3% dextran sodium sulfate for 7 days in drinking water. Colonic mucosal injury was assessed by clinical, macroscopic, biochemical and histopathological examinations. BE significantly decreased disease activity index and improved the macroscopic and histological score of colons when compared to the colitis group (P<.05). BE markedly attenuated myeloperoxidase accumulation (colitis group 54.97±2.78 nmol/mg, treatment group 30.78±1.33 nmol/mg) and malondialdehyde in colon and prostaglandin E2 level in serum while increasing the levels of superoxide dismutase and catalase (colitis group 11.94±1.16 U/ml, BE treatment group 16.49±0.39 U/ml) compared with the colitis group (P<.05). mRNA levels of the cyclooxygenase (COX)-2, interferon-γ, interleukin (IL)-1β and inducible nitric oxide synthase cytokines were determined by reverse transcriptase polymerase chain reaction. Immunohistochemical analysis showed that BE attenuates the expression of COX-2 and IL-1β in colonic tissue. Moreover, BE reduced the nuclear translocation of nuclear transcription factor kappa B (NF-κB) by immunofluorescence analysis. Thus, the anti-inflammatory effect of BE at colorectal sites is a result of a number of mechanisms: antioxidation, down-regulation of the expression of inflammatory mediators and inhibition of the nuclear translocation of NF-κB.

Antioxidant therapy for treatment of inflammatory bowel disease: Does it work?

Oxidative stress (OS) is considered as one of the etiologic factors involved in several signals and symptoms of inflammatory bowel diseases (IBD) that include diarrhea, toxic megacolon and abdominal pain. This systematic review discusses approaches, challenges and perspectives into the use of nontraditional antioxidant therapy on IBD, including natural and synthetic compounds in both human and animal models. One hundred and thirty four papers were identified, of which only four were evaluated in humans. Some of the challenges identified in this review can shed light on this fact: lack of standardization of OS biomarkers, absence of safety data and clinical trials for the chemicals and biological molecules, as well as the fact that most of the compounds were not repeatedly tested in several situations, including acute and chronic colitis. This review hopes to stimulate researchers to become more involved in this fruitful area, to warrant investigation of novel, alternative and efficacious antioxidant-based therapies.

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Major biomarkers used for evaluation of antioxidant therapy were MPO, TBARS/MDA and glutathione levels.

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Challenges were identified for the yet poor use of antioxidant therapy in IBD.

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This review stimulates the investigation of alternative and efficacious antioxidant therapies.

Animal models of ulcerative colitis developed with chemicals

In recent years, the incidence of ulcerative colitis (UC) has been rising obviously with the changes in people's diet (e.g., high fat diet), and it has become a common digestive system disease as well as a main cause of chronic diarrhea. Patients usually suffer from great pain because of the delayed recovery and repeated attacks of UC, and some of the patients may develop into colon cancer. At present, the pathogenesis of UC is not fully clear, anti-inflammatory drugs are mostly used clinically for the treatment of UC, but their efficacy is not satisfying. Therefore, it is of great significance to further investigate the etiology, mechanisms and new treatment strategies for UC using effective animal models of UC. There are many methods to establish animal models of UC. The present review mainly focuses on the mechanisms, characteristics and applications of UC animal models established using chemical substances.

Pyrrolidine Dithiocarbamate Inhibits NF-KappaB Activation and Upregulates the Expression of Gpx1, Gpx4, Occludin, and ZO-1 in DSS-Induced Colitis

Inflammatory bowel disease (IBD) correlates with oxidative stress, inflammation, and alteration in several signal pathways, including nuclear transcription factor-kappaB (NF-κB). Pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-κB, has been widely demonstrated to exhibit an antioxidant and anti-inflammatory function. This study aimed to test the hypothesis that NF-κB inhibitor PDTC confers a beneficial role in a colitis model induced by dextran sodium sulfate (DSS) in mouse. The results showed that DSS decreased daily weight gain, induced colonic inflammation, suppressed the expression of antioxidant enzymes and tight junctions, and activated NF-κB and nuclear factor erythroid 2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2/Keap1) signaling pathways. PDTC significantly upregulated (P < 0.05) Gpx1, Gpx4, occludin, and ZO-1 expressions in the DSS-induced colitis model. Meanwhile, PDTC reversed (P < 0.05) the activation of NF-κB signal pathway caused by DSS treatment. In conclusion, PDTC could serve as an adjuvant therapy for the patient with IBD.

The Sasa quelpaertensis Leaf Extract Inhibits the Dextran Sulfate Sodium-induced Mouse Colitis Through Modulation of Antioxidant Enzyme Expression

Background:

Oxidative stress plays an important role in the pathogenesis of inflammatory bowel disease. The objective of this study is to investigate the protective effect of Sasa quelpaertensis leaf extract (SQE) against oxidative stress in mice with dextran sulfate sodium (DSS)-induced colitis.

Methods:

Mice were treated with SQE (100 mg/kg or 300 mg/kg body weight) by gavage in advance two weeks before inflammation was induced. Then, the mice were administered with 2.5% DSS in drinking water for 7 days and normal drinking water for 7 days between two DSS treatment. Disease activity index values, gut motility, and severity of the resulting oxidative DNA damage were analyzed. The antioxidant effect of SQE was evaluated by measuring malondialdehyde (MDA) and superoxide dismutase (SOD) activity in plasma samples. Catalase activity and expressions levels of glutathione peroxidase 1 (Gpx1), SOD1, and SOD2 were also detected in colon tissues.

Results:

Administration of SQE significantly reduced the severity of DSS-induced colitis compared to the control (Ctrl) group. Levels of 8-oxo-dG, an oxidative DNA damage marker, were significantly lower in the SQE group compared to the untreated DSS Ctrl group. In the SQE (300 mg/kg) group, MDA levels were significantly lower, while SOD and catalase activity levels in the plasma samples were significantly higher compared with the DSS Ctrl group. The expression levels of the antioxidant enzymes, SOD2 and Gpx1, were significantly higher, while the levels of SOD 1 expression were lower, in the colon tissues of the DSS Ctrl group compared with those of the Ctrl group. In contrast, administration of SQE significantly down-regulated SOD2 and Gpx1 expressions and up-regulated SOD1 expression.

Conclusions:

These results indicate that SQE efficiently suppresses oxidative stress in DSS-induced colitis in mice, and its action is associated with the regulation of antioxidant enzymes.

Olive oil phenolic extract regulates interleukin-8 expression by transcriptional and posttranscriptional mechanisms in Caco-2 cells

In this study, we investigated the ability of a phenolic extract from extra virgin olive oil (OPE) to modulate the inflammatory response in intestinal epithelial cells. Undifferentiated and differentiated Caco-2 cells were challenged with LPS (50 μg/mL) or IL-1β (5 ng/mL) to mimic the early and intermediate phase of intestinal inflammation, respectively. The effects of OPE on nuclear factor-κB-driven transcription and IL-8 promoter activity were evaluated in transfection assays, coupled to p65 nuclear translocation. Modulation of IL-8 mRNA levels by OPE was measured by quantitative RT-PCR while effects on protein levels by ELISA. Specific mitogen activated protein kinases inhibitors were used to investigate mRNA stability and the involvement of related signaling pathways. OPE prevented IL-8 expression and secretion in LPS-treated Caco-2 cells. In the presence of IL-1β OPE exhibited opposing effects on IL-8 gene transcription and mRNA/protein levels. While in IL-1β-treated cells IL-8 promoter activity was inhibited by treatment with OPE, IL-8 mRNA stability was strongly enhanced, leading to increased protein expression. Inhibitors of p38 and extracellular signal-regulated kinases partly prevented OPE effect on IL-8 mRNA levels. Intestinal epithelial cells represent a direct target of the action of olive oil phenols where they regulate IL-8 expression by transcriptional and posttranscriptional mechanisms.

Dietary high-polyphenols extra-virgin olive oil is effective in reducing cholesterol content in eggs

BACKGROUND

Extra-virgin olive oil (EVOO) represents an important food in Mediterranean diet due to its favorable effects on human and animal health derived from the consumption of polyphenols. We studied the effects of dietary EVOO differing in polyphenols levels on egg quality.

METHODS

A total of 150 laying hens were allotted into three groups over 10 weeks of the experimental period. The three diets were based on wheat-soybean meal with added oils at 2.5%. Hens were fed the following diets: (1) commercial diet containing sunflower oil (Control), (2) diet EVOO from Cima di Bitonto variety (low-polyphenols content; Low-P), and (3) diet EVOO from Coratina variety (high-polyphenols content; High-P). The performance of the hen, the qualitative traits of eggs, and the fatty acid composition and cholesterol content of egg-yolk were measured.

RESULTS

None of the egg productive parameters studied were influenced by dietary treatment, except for yolk color score that was enhanced in hens fed the both EVOO diets (P<0.05). Feeding high-polyphenols EVOO reduced serum cholesterol level in hens (P<0.01) and egg-yolk cholesterol levels (as per egg; P<0.05). The dietary supplementation of high-polyphenols EVOO raised the polyunsaturated fatty acids (PUFAs) composition and increased the content of oleic and linolenic acids in egg-yolk. Moreover, the atherogenic index in egg-yolk decreased linearly in accordance with increasing levels of dietary polyphenols (P<0.01).

CONCLUSION

In conclusion, a diet for hens consisting of high-polyphenols level from extra-virgin olive oil can improve the fatty acid quality of egg-yolk while lowering the egg-yolk cholesterol level, which could be a beneficial functional food for human health.

Effects of dietary virgin olive oil polyphenols: hydroxytyrosyl acetate and 3, 4-dihydroxyphenylglycol on DSS-induced acute colitis in mice

Hydroxytyrosol, a polyphenolic compound from extra virgin olive oil (EVOO) has exhibited an improvement in a model of DSS-induced colitis. However, other phenolic compounds present such as hydroxytyrosyl acetate (HTy-Ac) and 3,4-dihydroxyphenylglycol (DHPG) need to be explored to complete the understanding of the overall effects of EVOO on inflammatory colon mucosa. This study was designed to evaluate the effect of both HTy-Ac and DHPG dietary supplementation in the inflammatory response associated to colitis model. Six-week-old mice were randomized in four dietary groups: sham and control groups received standard diet, and other two groups were fed with HTy-Ac and DHPG, respectively, at 0.1%. After 30 days, all groups except sham received 3% DSS in drinking water for 5 days followed by a regime of 5 days of water. Acute inflammation was evaluated by Disease Activity Index (DAI), histology and myeloperoxidase (MPO) activity. Colonic expression of iNOS, COX-2, MAPKs, NF-kB and FOXP3 were determined by western blotting. Only HTy-Ac-supplemented group showed a significant DAI reduction as well as an improvement of histological damage and MPO. COX-2 and iNOS protein expression were also significantly reduced. In addition, this dietary group down-regulated JNK phosphorylation and prevented the DSS-induced nuclear translocation level of p65. However, no significant differences were observed in the FOXP3 expression. These results demonstrated, for the first time, that HTy-Ac exerts an antiinflammatory effect on acute ulcerative colitis. We concluded that HTy-Ac supplement might provide a basis for developing a new dietary strategy for the prevention of ulcerative colitis.

Arginyl-glutamine dipeptide attenuates experimental colitis by enhancing antioxidant function and inhibiting nuclear factor-kappaB

This study aimed to investigate the effect and underlying mechanism of Arginyl-glutamine (AG) dipeptide on dextran sulfate sodium (DSS)-induced colitis byin vivoandin vitromodels.

Dietary squalene supplementation improves DSS-induced acute colitis by downregulating p38 MAPK and NFkB signaling pathways

SCOPE

Squalene is a polyunsaturated triterpene, which has exhibited anticancer and antioxidant activities among others. We investigated dietary squalene supplementation effect on an acute colitis model induced by dextran sulfate sodium (DSS) in C57BL/6 mice.

METHODS AND RESULTS

Mice were fed from weaning with squalene at 0.02% and 0.1%. After 4 weeks, mice were exposed to 3% DSS for 5 days developing acute colitis. After DSS removal (5 days), colons were histological and biochemically processed. Our results showed that dietary squalene treatment exerts anti-inflammatory action in DSS-induced acute colitis. Western blot revealed that squalene downregulated COX-2 (where COX is cyclooxygenase) and inducible nitric oxide synthase system by inhibition of mitogen-activated protein kinase p38 and the nuclear factor-kappa B signaling pathways, preventing an increase in the cytokines levels. Under our experimental conditions, STAT3 and FOXP3 (where FOXP3 is forkhead box P3) were not modified and the transcriptional regulation of antioxidant and/or detoxifying enzymes, Nrf2 (where Nrf2 is nuclear factor (erythroid-derived 2)-like 2), was reduced in DSS-induced colitis. However, any change could be observed after squalene supplementation.

CONCLUSION

Squalene was able to improve the oxidative events and returned proinflammatory proteins expression to basal levels probably through p38 mitogen-activated protein kinase and nuclear factor-kappa B signaling pathways. However, supplementary studies are needed in order to provide a basis for developing a new dietary supplementation strategy.

Dietary agents and phytochemicals in the prevention and treatment of experimental ulcerative colitis

Inflammatory bowel diseases (IBDs), consisting mainly of ulcerative colitis (UC) and Crohn's disease (CD), are important immune-mediated diseases of the gastrointestinal tract. The etiology of the disease includes environmental and genetic factors. Its management presents a constant challenge for gastroenterologists and conventional surgeon. 5-Amninosalicylates, antibiotics, steroids, and immune modulators have been used to reduce the symptoms and for maintenance of remission. Unfortunately, long-term usage of these agents has been found to lead to severe toxicities, which are deterrent to the users. Pre-clinical studies carried out in the recent past have shown that certain dietary agents, spices, oils, and dietary phytochemicals that are consumed regularly possess beneficial effects in preventing/ameliorating UC. For the first time, this review addresses the use of these dietary agents and spices in the treatment and prevention of IBD and also emphasizes on the mechanisms responsible for their effects.

Sasa quelpaertensis leaf extract suppresses dextran sulfate sodium-induced colitis in mice by inhibiting the proinflammatory mediators and mitogen-activated protein kinase phosphorylation

Sasa quelpaertensis leaves exert anti-inflammatory and anticarcinogenic effects, although it remains unclear whether these leaves can suppress inflammation-related intestinal diseases. This study hypothesized that Sasa quelpaertensis leaf extract (SQE) exerts a protective effect against inflammation in a dextran sulfate sodium (DSS)-induced colitis mouse model. Therefore, colon tissues of DSS-induced colitis mice that were treated with SQE were assayed for levels of proinflammatory markers, mitogen-activated protein kinase signaling, and activation of nuclear factor κB. For this purpose, mice were pretreated with SQE (100 mg/kg or 300 mg/kg body weight) by gavage for a 2-week period. Mice then received either SQE or sulfasalazine (100 mg/kg body weight) with 2.5% DSS in drinking water for 7 days twice daily and 7 days of tap water ad libitum between DSS treatment. Treatment with SQE was found to attenuate the severity of DSS-induced colitis, as assessed by disease activity index scores, shrinkage of colon length, and histopathologic changes. SQE reduced DSS-induced proliferation in distal colon tissues. It also significantly suppressed levels of tumor necrosis factor-α in serum and colon tissues, nitric oxide synthase, cyclooxygenase, and levels of phosphorylated c-Jun N-terminal kinases, p38, extracellular-signal-regulated kinases 1/2, and IκBα in colon tissues. To our knowledge, this is the first study to demonstrate that SQE supplementation can exert an anti-inflammatory effect on experimental chronic colitis.

Mangiferin attenuates the symptoms of dextran sulfate sodium-induced colitis in mice via NF-κB and MAPK signaling inactivation

Inflammatory bowel disease (IBD) is a chronic and relapsing inflammatory disorder of the gastrointestinal (GI) tract, and currently no curative treatment is available. Mangiferin, a natural glucosylxanthone mainly from the fruit, leaves and stem bark of a mango tree, has a strong anti-inflammatory activity. We sought to investigate whether mangiferin attenuates inflammation in a mouse model of chemically induced IBD. Pre-administration of mangiferin significantly attenuated dextran sulfate sodium (DSS)-induced body weight loss, diarrhea, colon shortening and histological injury, which correlated with the decline in the activity of myeloperoxidase (MPO) and the level of tumor necrosis factor-α (TNF-α) in the colon. DSS-induced degradation of inhibitory κBα (IκBα) and the phosphorylation of nuclear factor-kappa B (NF-κB) p65 as well as the mRNA expression of pro-inflammatory mediators (inducible NO synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1), TNF-α, interleukin-1β (IL-1β) and IL-6) in the colon were also downregulated by mangiferin treatment. Additionally, the phosphorylation/activation of DSS-induced mitogen-activated protein kinase (MAPK) proteins was also inhibited by mangiferin treatment. In accordance with the in vivo results, mangiferin exposure blocked TNF-α-stimulated nuclear translocation of NF-κB in RAW264.7 mouse macrophage cells. Transient transfection gene reporter assay performed in TNF-α-stimulated HT-29 human colorectal adenocarcinoma cells indicated that mangiferin inhibits NF-κB transcriptional activity in a dose-dependent manner. The current study clearly demonstrates a protective role for mangiferin in experimental IBD through NF-κB and MAPK signaling inhibition. Since mangiferin is a natural compound with little toxicity, the results may contribute to the effective utilization of mangiferin in the treatment of human IBD.