The unsaponifiable fraction of extra virgin olive oil promotes apoptosis and attenuates activation and homing properties of T cells from patients with inflammatory bowel disease.

The unsaponifiable fraction (UF) of extra virgin olive oil (EVOO) possesses anti-inflammatory properties and exerts preventative effects in murine models of inflammatory bowel disease (IBD). The present study was designed to determine the in vitro effects of UF on blood and intestinal T cells from IBD patients and healthy subjects. The T cell phenotype was investigated by flow cytometry and cytokine secretion was determined by ELISA. The presence of UF of EVOO promoted apoptosis and attenuated activation of intestinal and blood T cells isolated from IBD patients, decreasing the frequency of CD69(+) and CD25(+) T cells and, also, the secretion of IFN-γ. Moreover, UF reduced the expression of the gut homing receptor integrin ß7 on blood T cells from IBD patients. In conclusion, UF modulates the activity and the gut homing capacity of T cells, and might therefore be considered as a dietary complement with an anti-inflammatory role in IBD patients.

Extra virgin olive oil polyphenolic extracts downregulate inflammatory responses in LPS-activated murine peritoneal macrophages suppressing NFκB and MAPK signalling pathways.

Extra virgin olive oil (EVOO) is obtained from the fruit of the olive tree Olea europaea L. Phenolic compounds present in EVOO have recognized anti-oxidant and anti-inflammatory properties. However, the activity of the total phenolic fraction extracted from EVOO and the action mechanisms involved are not well defined. The present study was designed to evaluate the potential anti-inflammatory mechanisms of the polyphenolic extract (PE) from EVOO on LPS-stimulated peritoneal murine macrophages. Nitric oxide (NO) production was analyzed by the Griess method and intracellular reactive oxygen species (ROS) by fluorescence analysis. Moreover, changes in the protein expression of the pro-inflammatory enzymes, inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and microsomal prostaglandin E synthase-1 (mPGES-1), as well as the role of nuclear transcription factor kappa B (NFκB) and mitogen-activated protein kinase (MAPK) signalling pathways, were analyzed by Western blot. PE from EVOO reduced LPS-induced oxidative stress and inflammatory responses through decreasing NO and ROS generation. In addition, PE induced a significant down-regulation of iNOS, COX-2 and mPGES-1 protein expressions, reduced MAPK phosphorylation and prevented the nuclear NFκB translocation. This study establishes that PE from EVOO possesses anti-inflammatory activities on LPS-stimulated murine macrophages.

Melatonin modulates microsomal PGE synthase 1 and NF-E2-related factor-2-regulated antioxidant enzyme expression in LPS-induced murine peritoneal macrophages.

BACKGROUND AND PURPOSE: Increasing evidence demonstrates that melatonin regulates inflammatory and immune processes acting as both an activator and inhibitor of these responses. Nevertheless, the molecular mechanisms of its anti-inflammatory action remain unclear. Here we have characterized the cellular mechanisms underlying the redox modulation of LPS-stimulated inflammatory responses in murine peritoneal macrophages by melatonin to provide insight into its anti-inflammatory effects. EXPERIMENTAL APPROACH: Murine peritoneal macrophages were isolated and treated with melatonin in the presence or absence of LPS (5 µg·mL(-1) ) for 18 h. Cell viability was determined using sulforhodamine B assay and NO production was measured using the Griess reaction. Pro-inflammatory enzymes and transcription factors were detected by Western blotting. KEY RESULTS: Without affecting cell viability, melatonin (12.5, 25, 50 and 100 µM) reduced the level of nitrites, inducible NOS (iNOS), COX-2 and microsomal PGE synthase-1 (mPGES1) protein, and p38 MAPK phosphorylation, and prevented NF-κB translocation. Furthermore, melatonin treatment significantly increased NF-E2-related factor 2 (Nrf2) and haem oxygenase 1 (HO1) protein levels in murine macrophages exposed to LPS. CONCLUSIONS AND IMPLICATIONS: Melatonin reduced pro-inflammatory mediators and enhanced the expression of HO1 via NF-κB, p38 MAPK and Nrf2 cascade signalling pathways in murine macrophages. Thus, melatonin might be a promising target for diseases associated with overactivation of macrophages.

An up-date of olive oil phenols in inflammation and cancer: molecular mechanisms and clinical implications.

Olive oil (OO), the main fatty component of the Mediterranean diet, exhibits numerous biological functions which are beneficial for the state of health. In addition to monounsaturated fatty acid (MUFA) evidences have accumulated on the favorable properties of its minor though highly bioactive components, particularly the phenolic compounds, which have shown a broad spectrum of bioactive properties, including antioxidant and anti-inflammatory effects both associated with the origin of the main chronic diseases. Additional studies have demonstrated that the health effects of olive oil polyphenols have been also associated with their, neuroprotective, antiaging and antiatherogenic effects. On the other hand, because of their ability to modulate cell death, olive polyphenols have been proposed as chemopreventive and therapeutic agents. Thus, the purpose of this article is to review the chemistry, bioavailability and pharmacokinetic characteristics of OO polyphenols, in addition to provide the reader an up-date of their putative antioxidant, anti-inflammatory and anti-cancer activities as well as the plausible action mechanisms involved.

Abarema cochliacarpos reduces LPS-induced inflammatory response in murine peritoneal macrophages regulating ROS-MAPK signal pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Abarema cochliacarpos (Gomes) Barneby and Grimes (Fabaceae), known by the vulgar name of Babatenã, has been traditionally used in Northeast Brazil, as an anti-inflammatory remedy. Previous studies have demonstrated its anti-inflammatory and antiulcer effects in skin lesion, alcohol gastric ulcer and acute and chronic colitis. AIMS: The present study was designed to evaluate the antioxidant and anti-inflammatory effects of the butanolic fraction from A. cochliacarpos (BFAC) and its major flavonoid, (+)-catechin, in LPS-stimulated murine peritoneal macrophages. Moreover, we studied the role of mitogen-activated protein kinase (MAPK)s and NF-kB signaling pathways possibly involved in the beneficial effects. MATERIALS AND METHODS: The quantification of the extract was carried out by ultra-performance liquid chromatography analysis. Cell viability was determined using SRB assay. Nitric oxide (NO) production was analyzed by Griess method and intracellular reactive oxygen species (ROS) by fluorescence analysis. In addition, cyclooxygenase (COX-2) and inducible nitric oxide synthase (iNOS) expression, MAPK activation and IkappaBalpha (IKBα) degradation, were determined by Western blot. RESULTS: After BFAC characterization, (+)-catechin was revealed as its major constituent. Both BFAC and (+)-catechin, exerted significant anti-oxidant and anti-inflammatory effects inhibiting LPS-induced intracellular ROS and NO production in peritoneal macrophages. Additionally, the extract but also its major component reduced pro-inflammatory proteins expression probably through c-Jun N-terminal kinase and p38 MAPK signaling pathways. CONCLUSION: These data suggest that the beneficial effects of BFAC might be mediated, at least in part, by the presence of (+)-catechin. Conclusively our findings confirm the potential of A. cochliacarpos as a new therapeutic strategy for the management of inflammatory and oxidative stress-related diseases.

Dietary unsaponifiable fraction from extra virgin olive oil supplementation attenuates acute ulcerative colitis in mice.

Extra virgin olive oil (EVOO) has demonstrated immunomodulatory and antiinflammatory properties in murine experimental ulcerative colitis (UC). In addition to its high monounsaturated fatty acid content, evidences have accumulated on the favorable properties of minor, although highly bioactive, components present in the unsaponifiable fraction (UF). The present study was designed to evaluate the effects of dietary EVOO's UF supplementation on acute UC. C57BL/6 mice were fed from weaning with sunflower oil (SD), EVOO diet and UF-enriched SD at 5% oil (SD+UF). After 30 days, mice were exposed to 3% dextran sulfate sodium (DSS) for 5 days developing acute colitis. After 4 days of DSS removal, animals were sacrificed and colons were histological and biochemically processed. Disease activity index and microscopic damage score were significantly improved in EVOO and SD+UF dietary groups versus SD group. In addition, both dietary treatments significantly induced decreases in MCP-1 and TNF-α levels, iNOS and COX-2 overexpression and p38 MAPKs activation in colon mucosa. Moreover, an upregulation of IκB expression was also observed after feeding the animals with both diets. However, no statistically differences between data from mice fed with EVOO or UF+SD diets were observed. Dietary enrichment with EVOO's UF reduces the damage in acute colitis model, alleviating the oxidative events and returning proinflammatory proteins expression to basal levels probably through p38 MAPK and NFκB signalling pathways. EVOO's UF diet might provide a basis for developing a new strategy in dietary supplementation for the prevention of UC.

Influence of extra virgin olive oil diet enriched with hydroxytyrosol in a chronic DSS colitis model.

PURPOSE: Recent epidemiological studies have shown that habitual consumption of extra virgin olive oil (EVOO), the characteristic culinary fat of the Mediterranean area, is effective in the prevention of diverse types of digestive disorders such as inflammatory bowel disease. Many of these benefits are, in addition to its high proportion of oleic acid, due to the high content of phenolic compounds. METHODS: Six-week-old mice were randomized into three dietary groups: standard, EVOO and hydroxytyrosol-enriched EVOO. After 30 days, mice that were exposed to 3% DSS for 5 days developed acute colitis that progressed to severe chronic inflammation during a regime of 21 days of water. RESULTS: Diets enriched with EVOO significantly attenuated the clinical and histological signs of damage, improving results from disease activity index and reducing about 50% the mortality caused by DSS. Moreover, hydroxytyrosol supplement showed better results. Cytokines study showed that TNF-α was maintained near to sham control and IL-10 levels were significantly improved in EVOO and EVOO plus hydroxytyrosol diet-DSS groups. In the same way, COX-2 and iNOS were downregulated, and the activation of p38 MAPK was reduced. We also observed a higher significant reduction in iNOS in hydroxytyrosol-enriched EVOO compared with EVOO alone. CONCLUSIONS: EVOO diets exerted a noteworthy beneficial effect in chronic DSS-induced colitis by cytokine modulation and COX-2 and iNOS reduction via downregulation of p38 MAPK. In addition to the beneficial effect by EVOO, supplementation of the diet with hydroxytyrosol may improve chronic colitis through iNOS downregulation plus its antioxidant capacity.

Protective effect of ellagic acid, a natural polyphenolic compound, in a murine model of Crohn's disease.

Current epidemiological and experimental studies support a beneficial role of dietary polyphenols in several gastrointestinal diseases, including inflammatory bowel disease. The aim of this study was to gain a better understanding of the effects of a naturally occurring polyphenol, ellagic acid, present in some fruits such as pomegranate, raspberries and nuts among others, in an experimental murine model of Crohn's disease by intra-colonic administration of TNBS in rats. Analysis of the lesions were carried out by macroscopic and histological technics. Inflammation response was assessed by histology and myeloperoxidase activity. iNOS and COX-2 are upregulated by MAPKs and NF-κB nuclear transcription factor in intestinal epithelial cells thus, we determined the expression of iNOS, COX-2 and the involvement of the p38, JNK, ERK1/2 MAPKs and NF-κB signalling in the protective effect of EA by western blotting. Oral administration of EA (10-20 mg/kg) diminished the severity and extension of the intestinal injuries induced by TNBS although there was no observed a significant dose-response. In addition, EA increased mucus production in goblet cells in colon mucosa, decreased neutrophil infiltration and pro-inflammatory proteins COX-2 and iNOS overexpression. Also EA was capable of reducing the activation of p38, JNK and ERK1/2 MAPKs, preventing the inhibitory protein IκB-degradation and inducing an inhibition of the nuclear translocation level of p65 in colonic mucosa. In conclusion, EA reduces the damage in a rat model of Crohn's disease, alleviates the oxidative events and returns pro-inflammatory proteins expression to basal levels probably through MAPKs and NF-κB signalling pathways.

Extra-virgin olive oil-enriched diet modulates DSS-colitis-associated colon carcinogenesis in mice.

BACKGROUND & AIMS: Patients with inflammatory bowel disease (IBD) are at increased risk for developing ulcerative colitis (UC)-associated colorectal cancer (CRC). Several studies have shown that extra virgin olive oil (EVOO) might possess anti-inflammatory, antiproliferative and antiapoptotic effects. We have evaluated EVOO diet effects on the severity of repeated colitis-associated CRC. METHODS: Six-week-old C57BL/6 mice were randomized into two dietary groups: sunflower oil (SFO) and EVOO diets, both at 10%. Mice were exposed to 15 cycles of 0.7% dextran sodium sulphate (DSS) for 1 week followed by distilled water for 10 days. After, the rats were sacrificed and colonic damage was both histologically and biochemically assessed. RESULTS: Disease activity index (DAI) was significantly higher on SFO vs. EVOO diet at the end of the experimental period. EVOO-fed mice showed less incidence and multiplicity of tumors than in those SFO-fed mice. ß-catenin immunostaining was limited to cell membranes in control groups, whereas translocation from the cell membrane to the cytoplasm and/or nucleus was showed in DSS-treated groups and its expression was higher in SFO-fed animals. Cytokine production was significantly enhanced in SFO-fed mice, while this increase was not significant in EVOO-fed mice. Conversely, cyclooxygenase-2 (COX-2) and inducible nitric oxidase synthase (iNOS) expression were significantly lower in the animal group fed with EVOO than in the SFO group. CONCLUSIONS: These results confirm that EVOO diet has protective/preventive effect in the UC-associated CRC. This beneficial effect was correlated with a better DAI, a minor number of dysplastic lesions, a lower ß-catenin immunoreactivity, a proinflammatory cytokine levels reduction, a non modification of p53 expression and, COX-2 and iNOS reduction in the colonic tissue.