The potential use of polyphenols in the prevention and treatment of chronic inflammatory diseases has been extensively investigated although the mechanisms involved in cellular signaling need to be further elucidated. Cyanidin-3-glucoside is a typical anthocyanin of many pigmented fruits and vegetables widespread in the human diet. In the present study, the protection afforded by cyanidin-3-glucoside against cytokine-triggered inflammatory response was evaluated in the human intestinal HT-29 cell line, in comparison with 5-aminosalicylic acid, a well-established anti-inflammatory drug, used in inflammatory bowel disease. For this purpose, some key inflammatory mediators and inflammatory enzymes were examined. Our data showed that cyanidin-3-glucoside reduced cytokine-induced inflammation in intestinal cells, in terms of NO, PGE₂ and IL-8 production and of iNOS and COX-2 expressions, at a much lower concentration than 5-aminosalicylic acid, suggesting a higher anti-inflammatory efficiency. Interestingly, cyanidin-3-glucoside and 5-aminosalicylic acid neither prevented IkB-α degradation nor the activation of NF-kB, but significantly reduced cytokine-induced levels of activated STAT1 accumulated in the cell nucleus. In addition, we established that phosphorylated p38 MAPK was not involved in the protective effect of cyanidin-3-glucoside or 5-aminosalicylic acid. Taking into account the high concentrations of dietary anthocyanins potentially reached in the gastrointestinal tract, cyanidin-3-glucoside may be envisaged as a promising nutraceutical giving complementary benefits in the context of inflammatory bowel disease.

Luteolin efficiently fights intestinal inflammation. The inhibition of the JAK/STAT pathway by luteolin is a key mechanism.

The altered expression and subcellular distribution of tight junction (TJ) proteins, leading to a dysfunctional intestinal barrier, is a key mechanistic feature of inflammatory bowel disease (IBD). Therefore, increasing the integrity of the intestinal barrier by manipulating the TJ may constitute an innovative and effective therapeutic strategy in IBD. In this context, recent studies showed that dietary polyphenols are able to protect the intestinal TJ barrier integrity. Here, using a cellular model of intestinal inflammation, consisting of cytokine-stimulated HT-29 colon epithelial cells, we show that a polyphenolic extract obtained from Portuguese red wine (RWE) decreased the paracellular permeability across the cell monolayer compared with the control cells, even in the presence of pro-inflammatory cytokines. The beneficial effect of RWE was exerted at three complementary levels: (1) by promoting a significant increase of the mRNA of key barrier-forming TJ proteins, including occludin, claudin-5 and zonnula occludens (ZO)-1 above the levels observed in the control cells; (2) by preventing the decrease in the expression of these proteins under inflammatory conditions and (3) by averting the increase in claudin-2 mRNA, a channel-forming TJ protein induced by pro-inflammatory cytokines. Taken together, these results strongly suggest that polyphenols presented and consumed in red wine as a mixture can reinforce and protect the intestinal barrier against inflammatory stimulus by affecting the TJ protein expression and, thus, without the need for purifying individual compounds, might represent a readily available therapeutic intervention against IBD and intestinal inflammation.

The development of new therapeutic approaches, combining efficacy and safety against intestinal inflammation, notably inflammatory bowel disease (IBD), has emerged as an important goal due to the significant side effects and the lack of effectiveness of standard current therapies. Recently, several studies described the health-promoting effects of red wine, including anti-inflammatory properties, but the molecular mechanisms underlying its beneficial role remain largely unknown. Red wine is rich in phenolic compounds and it has been suggested that the positive effect of red wine intake might be attributed not only to the antioxidant properties of these compounds but also to the modulation of signalling cascades in connection with physiological and pathophysiological conditions such as inflammatory processes. This study assesses the potential anti-inflammatory action of a red wine extract (RWE) enriched in polyphenols in a cellular model of intestinal inflammation using cytokines-stimulated HT-29 colon epithelial cells. RWE suppressed cytokines-induced IκB degradation and interleukin-8 production in a dose-dependent manner. Coherently, key inflammatory mediators downstream NF-κB activation; notably cyclooxygenase-2 and inducible nitric oxide synthase were maintained at low levels by RWE in the presence of the cytokines. Additionally, RWE inhibited both the increase of nitric oxide derived from iNOS and of protein tyrosine nitration, a biomarker of nitrosative stress that typically requires the reaction of nitric oxide with the superoxide radical. Taken together, the anti-inflammatory action of RWE, mechanistically supported by the modulation of cascades orchestrated by NF-κB and involving nitric oxide, suggests that RWE (a readily straightforward preparation when compared with the purification of specific compounds) may represent a simple and inexpensive therapeutic strategy in the context of intestinal inflammation.

Salmonella enterica is a zoonotic foodborne pathogen that causes acute gastroenteritis in humans. We assessed the virulence potential of one-hundred and six Salmonella strains isolated from food animals and products. A high through-put virulence genes microarray demonstrated Salmonella Pathogenicity Islands (SPI) and adherence genes were highly conserved, while prophages and virulence plasmid genes were variably present. Isolates were grouped by serotype, and virulence plasmids separated S. Typhimurium in two clusters. Atypical microarray results lead to whole genome sequencing (WGS) of S. Infantis Sal147, which identified deletion of thirty-eight SPI-1 genes. Sal147 was unable to invade HeLa cells and showed reduced mortality in Galleria mellonella infection model, in comparison to a SPI-1 harbouring S. Infantis. Microarray and WGS of S. Typhimurium Sal199, established for the first time in S. Typhimurium presence of cdtB and other Typhi-related genes. Characterization of Sal199 showed cdtB genes were upstream of transposase IS911, and co-expressed with other Typhi-related genes. Cell cycle arrest, cytoplasmic distension, and nuclear enlargement were detected in HeLa cells infected by Sal199, but not with S. Typhimurium LT2. Increased mortality of Galleria was detected on infection with Sal199 compared to LT2. Thus, Salmonella isolates were rapidly characterized using a high through-put microarray; helping to identify unusual virulence features which were corroborated by further characterisation. This work demonstrates that the use of suitable screening methods for Salmonella virulence can help assess the potential risk associated with certain Salmonella to humans. Incorporation of such methodology into surveillance could help reduce the risk of emergence of epidemic Salmonella strains.

Dietary polyphenols are complex, natural compounds with recognized health benefits. Initially attractive to the biomedical area due to their in vitro antioxidant properties, the biological implications of polyphenols are now known to be far from their acute ability to scavenge free radicals but rather to modulate redox signaling pathways. Actually, it is now recognized that dietary polyphenols are extensively metabolized in vivo and that the chemical, biophysical and biological properties of their metabolites are, in most cases, quite different from the ones of the parent molecules. Hence, the study of the metabolic, absorptive and signaling pathways of both phenolics and derivatives has become a major issue. In this paper we propose a short-cut for the systemic effects of polyphenols in connection with nitric oxide (˙NO) biology. This free radical is a ubiquitous signaling molecule with pivotal functions in vivo. It is produced through an enzymatic pathway and also through the reduction of dietary nitrate and nitrite in the human stomach. At acidic gastric pH, dietary polyphenols, in the form they are conveyed in foods and at high concentration, not only promote nitrite reduction to ˙NO but also embark in a complex network of chemical reactions to produce higher nitrogen oxides with signaling functions, namely by inducing post-translational modifications. Modified endogenous molecules, such as nitrated proteins and lipids, acquire important physiological functions. Thus, local and systemic effects of ˙NO such as modulation of vascular tone, mucus production in the gut and protection against ischemia–reperfusion injury are, in this sense, triggered by dietary polyphenols. Evidence to support the signaling and biological effects of polyphenols by modulation of the nitrate–nitrite–NO pathway will be herein provided and discussed. General actions of polyphenols encompassing absorption and metabolism in the intestine/liver are short-cut via the production of diffusible species in the stomach that have not only a local but also a general impact.