Polyphenol-rich grape pomace extracts protect against dextran sulfate sodium-induced colitis in rats

Oxidative stress, hormones, and effects of natural antioxidants on intestinal inflammation in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic, relapsing gastrointestinal (GI) disorder characterized by intestinal inflammation. The etiology of IBD is multifactorial and results from a complex interplay between mucosal immunity, environmental factors, and host genetics. Future therapeutics for GI disorders, including IBD, that are driven by oxidative stress require a greater understanding of the cellular and molecular mechanisms mediated by reactive oxygen species (ROS). In the GI tract, oxidative stressors include infections and pro-inflammatory responses, which boost ROS generation by promoting the production of pro-inflammatory cytokines. Nuclear factor kappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2) represent two important signaling pathways in intestinal immune cells that regulate numerous physiological processes, including anti-inflammatory and antioxidant activities. Natural antioxidant compounds exhibit ROS scavenging and increase antioxidant defense capacity to inhibit pro-oxidative enzymes, which may be useful in IBD treatment. In this review, we discuss various polyphenolic substances (such as resveratrol, curcumin, quercetin, green tea flavonoids, caffeic acid phenethyl ester, luteolin, xanthohumol, genistein, alpinetin, proanthocyanidins, anthocyanins, silymarin), phenolic compounds including thymol, alkaloids such as berberine, storage polysaccharides such as tamarind xyloglucan, and other phytochemicals represented by isothiocyanate sulforaphane and food/spices (such as ginger, flaxseed oil), as well as antioxidant hormones like melatonin that target cellular signaling pathways to reduce intestinal inflammation occurring with IBD.

Polyphenols from foxtail millet bran ameliorate DSS-induced colitis by remodeling gut microbiome

INTRODUCTION

Polyphenols from plants possess the anti-inflammatory and gut microbiota modulated properties. Foxtail millet (Setaria italica L., FM) has potential medical and nutritional functions because of rich phenolic and other phytochemical components.

METHODS

Here, the study explored the effects of bound polyphenol of inner shell (BPIS) from FM bran on dextran sodium sulfate (DSS)-induced experimental colitis mice.

RESULTS

Results showed that BPIS administration effectively relieved the weight loss, decreased disease active index (DAI) scores, restrained the secretion of pro-inflammatory cytokines TNF-α, IL-6 and IL-1β, increased anti-inflammatory cytokines IL-10, IL-4, IL-5. BPIS prevented gut barrier damage by enhancing tight junction proteins Claudin1, ZO-1 and Occludin, increasing the number of goblet cells and facilitating the gene expressions of mucin family. In addition, BPIS restored the gut microbiota composition and increased the relative abundance of commensal bacteria such as Lachnospiraceae and Rikenellaceae and restrained the growth of S24-7 and Staphylococcaceae. Concentrations of short-chain-fatty acids (SCFAs) generated by gut microbiota were elevated in BPIS treated colitis mice.

CONCLUSION

These data suggest that BPIS effectively ameliorates DSS-induced colitis by preventing intestinal barrier damage and promoting gut microbiota community.

Evaluation of Radio Frequency-Assisted Enzymatic Extraction of Non-Anthocyanin Polyphenols from Akebia trifoliata Flowers and Their Biological Activities Using UPLC-PDA-TOF-ESI-MS and Chemometrics

A new radio frequency heating-assisted enzymatic extraction (RF-E) method is applied for the determination of phenolic compounds in Akebia trifoliata flowers, compared with hot water, acidified ethanol (EtOH), and enzymatic-assisted (EA) extractions. Non-anthocyanin polyphenol profiles, antibacterial, angiotensin-converting enzyme (ACE) inhibitory, anti-inflammatory activities, and structures of extracts are evaluated. Results show no significant differences in the extraction of total flavonoid content (15.85-16.63 mg QEs/g) and ACE inhibitory activity (51.30-52.86%) between RF-E and EA extracts. RF-E extract shows the highest anti-inflammatory activities. FTIR and UV spectra reveal that acidified EtOH treatment has a significant effect on the structure of the extract due to its highest flavonoid content (20.33 mg QEs/g), thus it has the highest antibacterial activity against Staphylococcus aureus and Escherichia coli. Sixteen non-anthocyanin polyphenols are identified by UPLC-PDA-TOF-ESI-MS and RF pre-treatment did not cause significant compound degradation. The chemometric analysis shows that enzymatic hydrolysis significantly increased biological activities, and the presence of non-anthocyanin polyphenols correlates well with ACE inhibitory and anti-inflammatory activities. Accordingly, A trifoliata flowers have potential as reagents for the food and pharmaceutical industries due to their abundant polyphenols that could be extracted efficiently using RF-E.

Grape Pomace Polyphenols as a Source of Compounds for Management of Oxidative Stress and Inflammation—A Possible Alternative for Non-Steroidal Anti-Inflammatory Drugs?

Flavonoids, stilbenes, lignans, and phenolic acids, classes of polyphenols found in grape pomace (GP), were investigated as an important alternative source for active substances that could be used in the management of oxidative stress and inflammation. The benefic antioxidant and anti-inflammatory actions of GP are presented in the literature, but they are derived from a large variety of experimental in vitro and in vivo settings. In these in vitro works, the decrease in reactive oxygen species, malondialdehyde, and thiobarbituric acid reactive substances levels and the increase in glutathione levels show the antioxidant effects. The inhibition of nuclear factor kappa B and prostaglandin E2 inflammatory pathways and the decrease of some inflammatory markers such as interleukin-8 (IL-8) demonstrate the anti-inflammatory actions of GP polyphenols. The in vivo studies further confirmed the antioxidant (increase in catalase, superoxide dismutase and glutathione peroxidase levels and a stimulation of endothelial nitric oxide synthase -eNOS gene expression) and anti-inflammatory (inhibition of IL-1𝛼, IL-1β, IL-6, interferon-𝛾, TNF-α and C-reactive protein release) activities. Grape pomace as a whole extract, but also different individual polyphenols that are contained in GP can modulate the endogenous pathway responsible in reducing oxidative stress and chronic inflammation. The present review analyzed the effects of GP in oxidative stress and inflammation, suggesting that it could become a valuable therapeutic candidate capable to reduce the aforementioned pathological processes. Grape pomace extract could become an adjuvant treatment in the attempt to reduce the side effects of the classical anti-inflammatory medication like non-steroidal anti-inflammatory drugs (NSAIDs).

Supplementation of polyphenol-rich grapes attenuates colitis, colitis-associated colon cancer and disease-associated dysbiosis in mice, but fails to mitigate colitis in antibiotic-treated mice

Polyphenols are known to interact with gut microbes that play key roles in maintaining gut health, but the role of gut microbiota modulation by polyphenols in mitigating colonic diseases is not fully established. We hypothesize that the interaction of polyphenols with the gut microbiota contributes to the attenuation of colitis and colitis-associated colon cancer (CAC). To test this hypothesis, we examined the effects of dietary supplementation of polyphenol-rich grape powder (GP) on azoxymethane (AOM) and dextran sulfate sodium (DSS)-induced colitis, CAC and the gut microbiota in mice (study 1), and further compared anti-colitis effects of GP in regular and antibiotic-treated mice (study 2). Compared to the control diet that has matched non-polyphenol contents, 10% GP, but not 3% GP, attenuated AOM-DSS induced colitis and tumor multiplicity by 29% (p<0.05). Ten percent GP increased gut bacterial evenness and counteracted CAC-induced decrease of bacterial evenness and changes of microbial composition. Remarkably, gut bacterial functional profiles of healthy mice and diseased mice fed 10% GP were similar, and both were significantly different from those of diseased mice with the control diet. Furthermore, 10% GP increased the relative abundance of butyrate-producing bacteria in the Lachnospiraceae family and enhanced the concentrations of fecal butyrate. Additionally, 10% GP mitigated DSS-induced colitis in conventional mice, but not the antibiotic-treated, gut microbe-depleted mice. Collectively, our studies demonstrate that grape polyphenols alleviate colonic diseases and prevent disease-associated dysbiosis, and their interaction with the gut microbiota may play a causative role in the protection of gut health.

l-Ergothioneine Exhibits Protective Effects against Dextran Sulfate Sodium-Induced Colitis in Mice

Background: Ulcerative colitis (UC) is a chronic disease of the intestinal tract in which excessive activation of inflammatory response is correlated. l-Ergothioneine (EGT) widely existing in mushrooms has various physiological activities. In this study, the protective effects of EGT on dextran sulfate sodium (DSS)-induced colitis mice were investigated. Results: It was observed that EGT administration, especially at the high dose level, prevented the body weight loss, the colon shortening, and the increase in disease activity index and spleen index caused by DSS. Moreover, EGT supplementation attenuated DSS-induced gut barrier damage by enhancing the expression of tight-junction protein and recovering the loss of gut mucus layer. Furthermore, EGT considerably decreased the colonic myeloperoxidase (MPO) activity induced by DSS, but no significant differences were observed in the concentrations of IL-6 and TNF-α in colon tissues. Additionally, EGT downregulated the populations of CD4⁺ T cells and macrophages, indicating that EGT stabilized the immune response caused by DSS. Conclusion: Together these results suggest that EGT can alleviate DSS-induced colitis and provide important insights concerning the potential anticolitis activity of such food products.

Mitigation of DSS-Induced Colitis Potentially via Th1/Th2 Cytokine and Immunological Function Balance Induced by Phenolic-Enriched Buckwheat (Fagopyrum esculentum Moench) Bee Pollen Extract

Colitis is an inflammatory disease that results from the overactivation of effector immune cells, producing a high quantity of pro-inflammatory cytokines. Our study aimed to explore whether buckwheat (F. esculentum) bee pollen extract (FBPE) could inhibit the progression of dextran sulfate sodium (DSS)-induced colitis via regulating immune function. We isolated and identified six main phenolic compounds of FBPE such as luteolin (9.46 mg/g) by column chromatography, HPLC-DAD, ESI-MS and NMR spectroscopy, then assessed their effects on colonic mucosal injury by clinical symptoms, histomorphology and immunohistochemistry examinations. The results showed that FBPE at 25.2 g/kg body weight (g/kg BW) changed the clinical symptoms of colitis, the ICAM-1 expression in colon, the activity of related inflammatory mediators in colon tissue and helped restore the immune system. Compared with the model group (40.28%), the CD4 positivity was significantly reduced in the HD (High-dose group: 25.2 g FBPE/kg BW/day) group (20.45%). Administration of 25.2 g/kg BW of FBPE decreased the IFN-γ, TNF-α and IL-4 levels, while enhancing the IL-10 level, and significantly inhibited the abnormally decreased IgG (Model: 13.25 mg/mL, HD: 14.06 mg/mL), showing a reversal effect on the Th1/Th2 levels in colitis. These findings suggested that FBPE at 25.2 g/kg BW had the effects of alleviating colitis and immunomodulation, which can help in the development of safe and effective immune therapy.

Lycium barbarum Polysaccharides and Capsaicin Inhibit Oxidative Stress, Inflammatory Responses, and Pain Signaling in Rats with Dextran Sulfate Sodium-Induced Colitis

Ulcerative colitis (UC) is an inflammatory disease with chronic relapsing symptoms. This study investigated the effects of Lycium barbarum polysaccharides (LBP) and capsaicin (CAP) in dextran sulfate sodium (DSS)-induced UC rats. Rats were divided into normal, DSS-induced UC, and UC treated with 100 mg LBP/kg bw, 12 mg CAP/kg bw, or 50 mg LBP/kg bw and 6 mg CAP/kg bw. Rats were fed LBP or CAP orally by gavage for 4 weeks, and UC model was established by feeding 5% DSS in drinking water for 6 days during week 3. Oral CAP and mixture significantly reduced disease activity index. Oral LBP significantly decreased serum malondialdehyde, interleukin (IL)-6, colonic tumor necrosis factor (TNF)-α levels, and protein expression of transient receptor potential cation channel V1 (TRPV1) and transient receptor potential ankyrin 1 (TRPA1), but increased serum catalase activity. Oral CAP significantly suppressed serum IL-6, colonic TRPV1 and TRPA1 protein expression, but elevated IL-10 levels, serum superoxide dismutase and catalase activities. The mixture of LBP and CAP significantly reduced serum IL-6, colonic TNF-α and TRPA1 protein. In conclusion, administration of LBP and/or CAP attenuate DSS-induced UC symptoms through inhibiting oxidative stress, proinflammatory cytokines, and protein expression of TRPV1 and TRPA1.

Bioactive Compounds from Pale Ale Beer Powder Attenuate Experimental Colitis in BALB/c Mice

Phenolic compounds (PCs) present in foods are associated with a decreased risk of developing inflammatory diseases. The aim of this study was to extract and characterize PCs from craft beer powder and evaluate their potential benefits in an experimental model of inflammatory bowel disease (IBD). PCs were extracted and quantified from pure beer samples. BALB/c mice received either the beer phenolic extract (BPE) or beer powder fortified with phenolic extract (BPFPE) of PCs daily for 20 days by gavage. Colon samples were collected for histopathological and immunohistochemical analyses. Dextran sodium sulfate (DSS)-induced mice lost more weight, had reduced colon length, and developed more inflammatory changes compared with DSS-induced mice treated with either BPE or BPFPE. In addition, in DSS-induced mice, the densities of CD4- and CD11b-positive cells, apoptotic rates, and activation of NF-κB and p-ERK1/2 MAPK intracellular signaling pathways were higher in those treated with BPE and BPFPE than in those not treated. Pretreatment with the phenolic extract and BPFPE remarkably attenuated DSS-induced colitis. The protective effect of PCs supports further investigation and development of therapies for human IBD.

Cherry Polyphenol Extract Ameliorated Dextran Sodium Sulfate-Induced Ulcerative Colitis in Mice by Suppressing Wnt/β-Catenin Signaling Pathway

Ulcerative colitis (UC) is a chronic and nonspecific inflammatory disease of the colon and rectum, and its etiology remains obscure. Cherry polyphenols showed potential health-promoting effects. However, both the protective effect and mechanism of cherry polyphenols on UC are still unclear. This study aimed to investigate the potential role of the free polyphenol extract of cherry in alleviating UC and its possible mechanism of action. Our study revealed that the free polyphenol extract of cherry management significantly alleviated UC symptoms, such as weight loss, colon shortening, the thickening of colonic mucous layer, etc. The free polyphenol extract of cherry treatment also introduced a significant reduction in levels of malondialdehyde (MDA), myeloperoxidase (MPO) and nitric oxide (NO), while causing a significant elevation in levels of catalase (CAT), glutathione (GSH-Px), superoxide dismutase (SOD), as well as the downregulation of pro-inflammatory cytokines. This indicated that such positive effects were performed through reducing oxidative damage or in a cytokine-specific manner. The immunofluorescence analysis of ZO-1 and occludin proteins declared that the free polyphenol extract of cherry had the potential to prompt intestinal barrier function. The reduced expression levels of β-catenin, c-myc, cyclin D1 and GSK-3β suggested that the cherry extract performed its positive effect on UC by suppressing the Wnt/β-ctenin pathway. This finding may pave the way into further understanding the mechanism of cherry polyphenols ameliorating ulcerative colitis.

Role of Gut Microbiota in the Anti-Colitic Effects of Anthocyanin-Containing Potatoes

SCOPE

Anthocyanin-containing potatoes exert anti-inflammatory activity in colitic mice. Gut bacterial dysbiosis plays a critical role in ulcerative colitis. This study examined the extent to which the anti-colitic activity of anthocyanin-containing red/purple-fleshed potatoes depends on the gut bacteria using a chemically-induced rodent model of colitis with the intact and antibiotic-ablated microbiome.

METHODS AND RESULTS

Four-week-old male mice (C57BL6) are randomly assigned to the control diet or 20% purple-/red-fleshed potatoes supplemented diet group. The microbiota-ablated group received an antibiotic cocktail in drinking water. At week nine, colitis is induced by 2% dextran sulfate sodium (DSS) in drinking water for five days. Administration of antibiotics resulted in a 95% reduction in gut bacterial load and fecal SCFAs. DSS-induced elevated gut permeability and body weight loss are more pronounced in antibiotic mice compared to non-antibiotic mice. Purple- or red-fleshed potato supplementation (20% w/w) ameliorated DSS-induced reduction in colon length and mucin 2 expression levels, and increase in permeability, spleen weight, myeloperoxidase (MPO) activity, and inflammatory cytokines (IL-6, IL-17, and IL1-β) expression levels in non-antibiotic mice, but not in gut microbiota ablated mice.

CONCLUSIONS

Anthocyanin-containing potatoes are potent in alleviating colitis, and the gut microbiome is critical for the anti-colitic activity of anthocyanin-containing potatoes.

Diet supporting therapy for inflammatory bowel diseases

PURPOSE

Non-specific inflammatory bowel diseases (IBD) include Crohn's disease and ulcerative colitis. More and more often attention is paid to the possibility of dietary support for inflammatory bowel diseases.

METHODS

The following review article considers the role of dietary components in the treatment of IBD as: pteridines, probiotics, bovine immunoglobulin, vitamin D, omega-3, flavonoids, polyphenols, curcumin and phosphatidylcholine. The article also discusses plant raw materials of arjuna, soy protein and nettles, trying to summarize their effect on quenching the inflammatory process within the intestines. This review focuses on the possibilities of dietary components and supplementation use to improve the pharmacotherapy response as well as the general clinical patients' condition.

RESULTS

The mechanism of action of supportive therapy is based on reduction in oxidative stress, maintaining the adequate balance between Th1 and Th2 lymphocytes by affecting cytokines, increasing riboflavin supply for macrophages, increasing expression of vitamin D receptor, regulation by decreasing the expression of NF-κB in liver cells and ability to inhibit the COX2 entrance and inactivate prostaglandins that are involved in the inflammatory process and 12-lipoxygenase pathway inhibition.

CONCLUSION

Considering clinical researches, it seems that the use of the above-mentioned ingredients in the diet of patients suffering IBD may positively influence the treatment process and maintenance of remission.

Grape seed proanthocyanidin extract ameliorates dextran sulfate sodium-induced colitis through intestinal barrier improvement, oxidative stress reduction, and inflammatory cytokines and gut microbiota modulation

It is widely believed that grape seed proanthocyanidin extract (GSPE) exerts antioxidant and anti-inflammatory effects. Dietary supplementation with GSPE has been reported to alleviate colitis signs in mice, but the mechanisms involved require further exploration. The present study investigated how the oral administration of GSPE ameliorates colitis signs and reduces colitis-associated inflammation. C57BL/6 mice were treated with GSPE for 21 days. During the final 7 days of treatment, the mice were administered dextran sulfate sodium (DSS) dissolved in drinking water to induce experimental colitis. We found that GSPE treatment improved DSS-induced colitis, which was evidenced by decreases in disease activity index (DAI) scores, pathological scores, and oxidative stress and increases in zonula occludens-1 (ZO-1), occludin, and claudin-1 mRNA levels of colon tissue. Notably, the proinflammatory cytokines TNF-α and IL-1β were significantly downregulated as a result of GSPE treatment in colon tissues. GSPE treatment also reduced NLR family pyrin domain-containing 3 (NLRP3) inflammasome mRNA levels of colon tissue. Furthermore, an analysis of 16S rRNA sequences showed that GSPE rebalanced the DSS-damaged gut microbiota, including reducing Bacteroidetes, Dubosiella, and Veillonella, increasing Verrucomicrobia and Akkermansia, and elevating the Firmicutes to Bacteroidetes ratio. In conclusion, GSPE supplementation alleviates DSS-induced colitis by modulating inflammatory cytokines and oxidation stress, maintaining the intestinal barrier, and improving the microbial community. These results indicate that GSPE might be a new dietary strategy for the treatment of ulcerative colitis.

Anthocyanin-containing purple potatoes ameliorate DSS-induced colitis in mice

Ulcerative colitis (UC), a major form of inflammatory bowel disease (IBD), is on the rise worldwide. Approximately three million people suffer from IBD in the United States alone, but the current therapeutic options (e.g., corticosteroids) come with adverse side effects including reduced ability to fight infections. Thus, there is a critical need for developing effective, safe and evidence-based food products with anti-inflammatory activity. This study evaluated the antiinflammatory potential of purple-fleshed potato using a dextran sodium sulfate (DSS) murine model of colitis. Mice were randomly assigned to control (AIN-93G diet), P15 (15% purple-fleshed potato diet) and P25 (25% purple-fleshed potato diet) groups. Colitis was induced by 2% DSS administration in drinking water for six days. The results indicated that purple-fleshed potato supplementation suppressed the DSS-induced reduction in body weight and colon length as well as the increase in spleen and liver weights. P15 and P25 diets suppressed the elevation in the intestinal permeability, colonic MPO activity, mRNA expression and protein levels of pro-inflammatory interleukins IL-6 and IL-17, the relative abundance of specific pathogenic bacteria such as Enterobacteriaceae, Escherichia coli (E. coli) and pks⁺ E. coli, and the increased flagellin levels induced by DSS treatment. P25 alone suppressed the elevated systemic MPO levels in DSS-exposed mice, and elevated the relative abundance of Akkermansia muciniphila (A. muciniphila) as well as attenuated colonic mRNA expression level of IL-17 and the protein levels of IL-6 and IL-1β. Therefore, the purple-fleshed potato has the potential to aid in the amelioration of UC symptoms.

Dietary Grape Seed Meal Bioactive Compounds Alleviate Epithelial Dysfunctions and Attenuates Inflammation in Colon of DSS-Treated Piglets

Inflammatory Bowel Diseases (IBD) are chronic inflammations associated with progressive degradation of intestinal epithelium and impairment of the local innate immune response. Restoring of epithelial integrity and of the mucosal barrier function, together with modulation of inflammatory and innate immune markers, represent targets for alternative strategies in IBD. The aim of our study was to evaluate the effects of a diet including 8% grape seed meal (GSM), rich in bioactive compounds (polyphenols, polyunsaturated fatty acids (PUFAs), fiber) on the markers of colonic epithelial integrity, mucosal barrier function, pro-inflammatory, and innate immunity in DSS-treated piglets used as animal models of intestinal inflammation. Our results have demonstrated the beneficial effects of bioactive compounds from dietary GSM, exerted at three complementary levels: (a) restoration of the epithelial integrity and mucosal barrier reinforcement by modulation of claudins, Occludin (OCCL) and Zonula-1 (ZO-1) tight junction genes and proteins, myosin IXB (MYO9B) and protein tyrosine phosphatase (PTPN) tight junction regulators and mucin-2 (MUC2) gene; (b) reduction of pro-inflammatory MMP-2 (matrix metalloproteinase-2) and MMP-9 (matrix metalloproteinase-9) genes and activities; and (c) suppression of the innate immune TLR-2 (Toll-like receptor-2) and TLR-4 (Toll-like receptor-4) genes and attenuation of the expression of MyD88 (Myeloid Differentiation Primary Response 88)/MD-2 (Myeloid differentiation factor-2) signaling molecules. These beneficial effects of GSM could further attenuate the transition of chronic colitis to carcinogenesis, by modulating the in-depth signaling mediators belonging to the Wnt pathway.

Plant Polyphenols-Biofortified Foods as a Novel Tool for the Prevention of Human Gut Diseases

Plant food biofortification is recently receiving remarkable attention, as it aims to increase the intake of minerals, vitamins, or antioxidants, crucial for their contribution to the general human health status and disease prevention. In this context, the study of the plant’s secondary metabolites, such as polyphenols, plays a pivotal role for the development of a new generation of plant crops, compensating, at least in part, the low nutritional quality of Western diets with a higher quality of dietary sources. Due to the prevalent immunomodulatory activity at the intestinal level, polyphenols represent a nutritionally relevant class of plant secondary metabolites. In this review, we focus on the antioxidant and anti-inflammatory properties of different classes of polyphenols with a specific attention to their potential in the prevention of intestinal pathological processes. We also discuss the latest biotechnology strategies and new advances of genomic techniques as a helpful tool for polyphenols biofortification and the development of novel, healthy dietary alternatives that can contribute to the prevention of inflammatory bowel diseases.

Biologically active compounds contained in grape pomace

A healthy lifestyle and gastronomic trends based on traditional and local foods accompanied by waste-free technologies are currently in the primary focus. One of the raw materials with properties in alignment with such requirements is grape pomace. This paper evaluates the antioxidant activity of grape pomace (which is homogenized into a brown powder) and selected commonly available commercial flours – wheat bread, rye plain, and rye whole grain flour – using DPPH (2,2‑diphenyl-1-picryl-hydrazyl-hydrate) and total polyphenol content method, where was used Folin-Ciocalteaure agent and then it was determined by spectrophotometric method (the measure of absorbance). The total amount of polyphenols in grape pomace was measured of 47.94 mg GAE.g-1, but the value 0.27 mg GAE.g-1 was measured in wheat bread flour. Grape pomace performed the antioxidant activity of 57.45 mg AAE.g-1, whereas wheat bread flour of only 0.21 mg AAE.g‑1 Compared to selected commercial flours, the total amount of polyphenols in grape pomace was up to 150 times higher and the ratio of antioxidant activity between grape pomace and wheat bread flour was even more than 280 times higher. This makes it possible to fortify commercial, commonly available flours with different amount of grape pomace so that products with a higher amount of biologically active substances can be prepared. Another benefit could be a reduction in health risks and a contribution to improving consumer health.

Grape pomace inhibits colon carcinogenesis by suppressing cell proliferation and inducing epigenetic modifications

Grape pomace (GP), a by-product of the wine and juice industry, is rich in bioflavonoids and dietary fibers. We hypothesized that GP has protective effects against colitis-associated colorectal cancer (CRC). Nine-week-old female mice were fed a control diet (CON) or CON with 5% grape pomace (GP) for 2 weeks, when mice were subjected to azoxymethane (AOM)/dextran sulfate sodium (DSS) induced-CRC induction. GP supplementation ameliorated the disease activity index (DAI) score, reduced tumor number, tumor size and pathological scores in AOM/DSS treated mice. Furthermore, dietary GP suppressed colonic expression of inflammatory cytokines, IL-1β and TNF-α, and inhibited NF-κB inflammatory signaling, while increased anti-inflammatory cytokine TGF-β mRNA expression. Colorectal inflammation is known to enhance Wnt signaling and cell proliferation. In agreement, the content of β-catenin, a key downstream mediator of Wnt signaling, was reduced as was the expression of Cyclin D1, phosphorylation and content of p53 and PCNA level in GP-fed mice. In addition, GP reduced the expression of ALDH1, a marker of cell stemness, and increased the expression of Cdx2, a key transcription factor initiating epithelial cell differentiation, DNA methylation of the promoter region of Cdx2 gene and hypermethylation of CpG island methylator phenotype (CIMP), which commonly occurs during CRC carcinogenesis, was alleviated in the GP group. In conclusion, GP supplementation suppressed colitis-associated CRC carcinogenesis, which was associated with the suppression of inflammation and cell proliferation and the enhancement of DNA demethylation in Cdx2 and CIMP genes in the colon. These data suggest that dietary GP supplementation has preventive effects against colorectal carcinogenesis.

A food pyramid, based on a review of the emerging literature, for subjects with inflammatory bowel disease

Emerging literature suggests that diet plays an important modulatory role in inflammatory bowel disease (IBD) through the management of inflammation and oxidative stress. The aim of this narrative review is to evaluate the evidence collected up till now regarding optimum diet therapy for IBD and to design a food pyramid for these patients. The pyramid shows that carbohydrates should be consumed every day (3 portions), together with tolerated fruits and vegetables (5 portions), yogurt (125ml), and extra virgin olive oil; weekly, fish (4 portions), white meat (3 portions), eggs (3 portions), pureed legumes (2 portions), seasoned cheeses (2 portions), and red or processed meats (once a week). At the top of the pyramid, there are two pennants: the red one means that subjects with IBD need some personalized supplementation and the black one means that there are some foods that are banned. The food pyramid makes it easier for patients to decide what they should eat.

Dietary polyphenol impact on gut health and microbiota

Polyphenols are naturally occurring compounds in plants and they are the most abundant antioxidants in the human diet. Due to their considerable structural diversity, this largely influences their bioavailability. Since a large proportion of polyphenols remains unabsorbed along the gastrointestinal tract, they may accumulate in the large intestine, where most of them are extensively metabolized by the intestinal microbiota. The formation of bioactive polyphenol-derived metabolites may also benefit the health status of the subjects, although the mechanisms have not been delineated. This review aims to highlight the impact of polyphenols on gut health and the modes of action could be through modulation of intestinal barrier function, innate and adaptive immune response, signaling pathways, as well as the ability to modify gut microbiota composition. The review will conclude by presenting future perspective and challenges of polyphenols application in food products to be used for preventing or treating diseases.

Effects of Dietary Grape Seed Meal Bioactive Compounds on the Colonic Microbiota of Weaned Piglets With Dextran Sodium Sulfate-Induced Colitis Used as an Inflammatory Model

Microbiota affects host health and plays an important role in dysbiosis. The study examined the effect of diet including grape seed meal (GSM) with its mixture of bioactive compounds on the large intestine microbiota and short-chain fatty acid synthesis in weaned piglets treated with dextran sodium sulfate (DSS) as a model for inflammatory bowel diseases. Twenty-two piglets were included in four experimental groups based on their diet: control, DSS (1 g/kg/b.w.+control diet), GSM (8% grape seed meal inclusion in control diet), and DSS+GSM (1 g/kg/b.w., 8% grape seed meal in control diet). After 30 days, the colon content was isolated and used for microbiota sequencing on an Illumina MiSeq platform. QIIME 1.9.1 pipeline was used to process the raw sequences. Both GSM and DSS alone and in combination affected the diversity indices and Firmicutes:Bacteroidetes ratio, with significantly higher values in the DSS-afflicted piglets for Proteobacteria phylum, Roseburia, Megasphera and CF231 genus, and lower values for Lactobacillus. GSM with high-fiber, polyphenol and polyunsaturated fatty acid (PUFA) content increased the production of butyrate and isobutyrate, stimulated the growth of beneficial genera like Prevotella and Megasphaera, while countering the relative abundance of Roseburia, reducing it to half of the DSS value and contributing to the management of the DSS effects.

Pomegranate peel extract alters the microbiome in mice and dysbiosis caused by Citrobacter rodentium infection

Treatment of mice with a pomegranate peel extract (PPX) decreased the pathogenicity of Citrobacter rodentium (Cr) infections. Here, we investigate the effects of PPX on the microbiome of uninfected or Cr-infected C3H/HeNCr mice by 16S rRNA gene sequencing. Mice were treated with water or PPX for 14 days, feces were collected, and then, the mice were infected with Cr and feces collected again at day 6 postinfection. DNA was isolated from the fecal samples and subjected to 16S rRNA gene sequencing to determine the microbial composition. Differences in the composition of the microbiome were observed for untreated and PPX-treated mice with PPX mice having decreased diversity. PPX treatment decreased the Firmicutes/Bacteroidetes ratio by increasing Bacteroidetes and decreasing Firmicutes levels. The decrease in Firmicutes was driven by a large reduction in Lactobacillus. PPX treatment increased the abundance of Proteobacteria and Verrucomicrobiae and decreased Actinobacteria. The relative abundance of Cr reached 22% in water-treated but only 5% in PPX-treated infected mice. These results suggest that consumption of pomegranate polyphenols altered the microbiome, making it more resistant to displacement by infection with Cr, indicating that pomegranate polyphenols may mitigate the pathogenic effects of food-borne bacterial pathogens.

The Anti-inflammatory Effects of Dietary Anthocyanins against Ulcerative Colitis

Ulcerative colitis (UC), which is a major form of inflammatory bowel disease (IBD), is a chronic relapsing disorder of the gastrointestinal tract affecting millions of people worldwide. Alternative natural therapies, including dietary changes, are being investigated to manage or treat UC since current treatment options have serious negative side effects. There is growing evidence from animal studies and human clinical trials that diets rich in anthocyanins, which are pigments in fruits and vegetables, protect against inflammation and increased gut permeability as well as improve colon health through their ability to alter bacterial metabolism and the microbial milieu within the intestines. In this review, the structure and bioactivity of anthocyanins, the role of inflammation and gut bacterial dysbiosis in UC pathogenesis, and their regulation by the dietary anthocyanins are discussed, which suggests the feasibility of dietary strategies for UC mitigation.

Mulberry juice freeze-dried powder attenuates the disease severity by the maintaining of colon mucosa in mice with DSS-induced acute colitis

This study aimed to evaluate the microbial compositions and gene expression related to inflammation in dextran sodium sulfate (DSS)-induced acute colitis and the effect of mulberry supplementation. Male BALB/c mice received a diet supplemented with mulberry juice freeze-dried powder (MFP) or not for 3 weeks. After 3 weeks, the mice received water containing 5% (w/v) DSS or not for 1 week. The disease activity index score in mice fed MFP was significantly decreased. A significant decrease in Bifidobacterium spp. and the Clostridium perfringens subgroup was observed in mice not fed MFP. The number of goblet cell and NLRP6 expression were observed in mice fed a diet supplemented with MFP compared with mice not fed MFP. These results may indicate that mulberry mitigates DSS-induced acute colitis by a changing the gut microbial flora and by improving mucosal conditions.

Grape peel powder promotes intestinal barrier homeostasis in acute TNBS-colitis: A major role for dietary fiber and fiber-bound polyphenols

Inflammatory bowel diseases are characterized by impaired intestinal barrier function. This study aimed to evaluate the effects of grape peel powder (GPP) and its bioactive rich-fractions on the barrier function and colonic injury in a model of colitis induced by 2,4,6 trinitrobenzene sulfonic acid (TNBS). Wistar rats received diets supplemented with either GPP (8%), extractable polyphenols (EP), non-extractable polyphenols-rich fraction (NEP-F), or polyphenols-poor, fiber-rich fraction (F) from grapes at amounts equivalent to the GPP group during 15 days before and for 7 days after colitis induction. NEP-F has decreased the extension of colonic lesion but the other grape peel bioactive fractions did not protect against macroscopic or microscopic colonic damage, EP diet increased macroscopic colonic damage. GPP, EP, and NEP-F reduced claudin-2 mRNA expression, whereas GPP and F fraction increased occludin and ZO-1 mRNA expression. All experimental diets reduced the colitis-triggered increase of MMP-9 mRNA expression. Colitis reduced by 30% the production of cecal short-chain fatty acids (SCFA). GPP and NEP-F completely protected against this effect, whereas F fraction was ineffective. Only GPP and NEP-F were able to decrease the upregulation of GRP94 mRNA triggered by colitis. Dietary fiber seems to reestablish the intestinal barrier function, whereas fiber-bound phenolics were able to restore cecal metabolism to produce beneficial metabolites like SCFA and to reduce the activation of the unfolded protein response.

The Role of Wine in Modulating Inflammatory Processes: A Review

Several epidemiological studies associated the consumption of wine with the reduction of the risk factors for cardiovascular disease and certain cancers, as well as for diabetes. These conditions are characterized by inflammatory mechanisms in addition to other biological mechanisms. Acute and chronic inflammation is mediated by a plethora of biomarkers production and pathway activation. Since the health promoting properties of wine in different pathological conditions may include the reduction of inflammation, the aim of this paper was to collect and review the in vitro, in vivo, and human studies performed to evaluate the effects of wine on different models of inflammation. Although great variability in wine intake, period of consumption, and content of phenolic compounds was observed, data from both human and animal studies showed a positive modulation of inflammatory biomarkers (cytokines, coagulation parameters) and oxidative stress (mainly malondialdehyde) involved in cardiovascular function. In addition, some convincing evidence was obtained in different models suggesting a positive modulation of risk factors for gastric and intestinal inflammation. Contradictory results were obtained for metabolic syndrome and type 2 diabetes. To date, no significant paper has been published in the area of immune function. Integrating in vivo data and in vitro studies, the NF-κB pathway has been identified as a critical target for the protective properties of a moderate wine consumption.

An update on dietary consideration in inflammatory bowel disease: anthocyanins and more

Inflammatory bowel disease (IBD) is a chronic idiopathic inflammatory disorder. A wealth of data pointed out that various aspects of chronic inflammation may be affected by several specific dietary factors. This paper calls attention to anthocyanins enriched plant food and anthocyanin dietary supplements, whose role in the management of IBD and its associated oncogenesis deems crucial. Area covered: We updated the most relevant dietary anthocyanins with potential anti-colitis and preventive effect on inflammatory associated colorectal cancer based on the recent animal and human researches along with revealing the major cellular and molecular mechanisms of action. Mounting evidence reported that anthocyanins enriched plant foods perform their protective role on IBD and inflammatory-induced colorectal cancer via different cellular transduction signaling pathways, including inflammatory transcription factors, SAPK/JNK and p38 MAPK cascade, JAK/STAT signaling, NF-kB/pERK/MAPK, Wnt signaling pathway, Nrf2 cytoprotective pathway as well as AMPK pathway and autophagy. Expert commentary: Combination of anthocyanins enriched dietary supplements with existing medications can provide new therapeutic options for IBD patients. Further, well-designed randomized control trials (RCTs) are essential to evaluate the role of anthocyanins enriched medicinal foods as well as isolated anthocyanin components as promising preventive and therapeutic dietary agents for IBD and its associated oncogenesis.

Secretory leukoprotease inhibitor is required for efficient quercetin-mediated suppression of TNFα secretion

Dendritic cells (DCs) are professional antigen presenting cells (APCs) that in response to microbial infections generate long-lasting adaptive immune response. Following microbial uptake, DCs undergo a cascade of cellular differentiation that ultimately leads to “mature” DCs. Mature DCs produce a variety of inflammatory cytokines, including tumor necrosis factor-α (TNFα) a key cytokine for the inflammatory cascade. In numerous studies, polyphenols, including quercetin, demonstrated their ability to suppress TNFα secretion and protect from the onset of chronic inflammatory disorders. We show that murine bone marrow derived DCs express Slpi following quercetin exposure. Slpi is known to suppress LPS mediated NFκB activation, thus, it was hypothesized that its expression could be the key step for polyphenol induced inflammatory suppression. Slpi-KO DCs poorly respond to quercetin administration failing to reduce TNFα secretion in response to quercetin exposure. Supernatant from quercetin exposed DCs could also reduce LPS-mediated TNFα secretion by unrelated DCs, but this property is lost using an anti-Slpi antibody. In vivo, oral administration of quercetin is able to induce Slpi expression. Human biopsies from inflamed tract of the intestine reveal the presence of numerous SLPI⁺ cells and the expression level could be further increased by quercetin administration. We propose that quercetin induces Slpi expression that in turn reduces the inflammatory response. Our data encourages the development of nutritional strategies to improve the efficiency of current therapies for intestinal chronic inflammatory syndrome and reduce the risks of colorectal cancer development.

Muscadine Grape (Vitis rotundifolia) or Wine Phytochemicals Reduce Intestinal Inflammation in Mice with Dextran Sulfate Sodium-Induced Colitis

The objective of this study was to determine the anti-inflammatory effects of phytochemical extracts from muscadine grapes or wine on dextran sulfate sodium (DSS)-induced colitis in mice and to investigate cellular mechanisms. Two groups of C57BL/6J mice were gavaged with muscadine grape phytochemicals (MGP) or muscadine wine phytochemicals (MWP), respectively, for 14 days. Acute colitis was induced by 3% DSS in drinking water for 7 days. An additional two groups of mice served as healthy and disease controls. Results indicated that MGP or MWP significantly prevented weight loss, reduced disease activity index, and preserved colonic length compared to the colitis group (p ≤ 0.05). MGP or MWP significantly decreased myeloperoxidase activity as well as the levels of IL-1β, IL-6, and TNF-α in colon (p ≤ 0.05). MGP or MWP caused down-regulation of the NF-κB pathway by inhibiting the phosphorylation and degradation of IκB in a dose-dependent manner. These findings suggest that phytochemicals from muscadine grape or wine mitigate ulcerative colitis via attenuation of pro-inflammatory cytokine production and modulation of the NF-κB pathway.

Phenolics profiling of pomace extracts from different grape varieties cultivated in Argentina

Grape pomace can be considered as an excellent and inexpensive source of phenolic compounds with potential bioactive properties.

Dietary supplementation of Thai black rice bran extract and yeast beta-glucan protects the dextran sodium sulphate mediated colitis induced rat

The present study was employed to evaluate the impact of black rice bran (RB) extract, and yeast β-glucan (YBG) supplementation on a dextran sodium sulfate (DSS)-induced colitis rat model.

Red Grape Skin Polyphenols Blunt Matrix Metalloproteinase-2 and -9 Activity and Expression in Cell Models of Vascular Inflammation: Protective Role in Degenerative and Inflammatory Diseases

Matrix metalloproteinases (MMPs) are endopeptidases responsible for the hydrolysis of various components of extracellular matrix. MMPs, namely gelatinases MMP-2 and MMP-9, contribute to the progression of chronic and degenerative diseases. Since gelatinases' activity and expression are regulated by oxidative stress, we sought to evaluate whether supplementation with polyphenol-rich red grape skin extracts modulated the matrix-degrading capacity in cell models of vascular inflammation. Human endothelial and monocytic cells were incubated with increasing concentrations (0.5-25 μg/mL) of Negroamaro and Primitivo red grape skin polyphenolic extracts (NSPE and PSPE, respectively) or their specific components (0.5-25 μmol/L), before stimulation with inflammatory challenge. NSPE and PSPE inhibited, in a concentration-dependent manner, endothelial invasion as well as the MMP-9 and MMP-2 release in stimulated endothelial cells, and MMP-9 production in inflamed monocytes, without affecting tissue inhibitor of metalloproteinases (TIMP)-1 and TIMP-2. The matrix degrading inhibitory capacity was the same for both NSPE and PSPE, despite their different polyphenolic profiles. Among the main polyphenols of grape skin extracts, trans-resveratrol, trans-piceid, kaempferol and quercetin exhibited the most significant inhibitory effects on matrix-degrading enzyme activities. Our findings appreciate the grape skins as rich source of polyphenols able to prevent the dysregulation of vascular remodelling affecting degenerative and inflammatory diseases.

Bioactivity of Polyphenols: Preventive and Adjuvant Strategies toward Reducing Inflammatory Bowel Diseases-Promises, Perspectives, and Pitfalls

Inflammatory bowel diseases (IBDs) are characterized by autoimmune and inflammation-related complications of the large intestine (ulcerative colitis) and additional parts of the digestive tract (Crohn's disease). Complications include pain, diarrhoea, chronic inflammation, and cancer. IBD prevalence has increased during the past decades, especially in Westernized countries, being as high as 1%. As prognosis is poor and medication often ineffective or causing side effects, additional preventive/adjuvant strategies are sought. A possible approach is via diets rich in protective constituents. Polyphenols, the most abundant phytochemicals, have been associated with anti-inflammatory, antioxidant, immunomodulatory, and apoptotic properties. Locally reducing oxidative stress, they can further act on cellular targets, altering gene expression related to inflammation, including NF-κB, Nrf-2, Jak/STAT, and MAPKs, suppressing downstream cytokine formation (e.g., IL-8, IL-1β, and TNF-α), and boosting the bodies' own antioxidant status (HO-1, SOD, and GPx). Moreover, they may promote, as prebiotics, healthy microbiota (e.g., Bifidobacteria, Akkermansia), short-chain fatty acid formation, and reduced gut permeability/improved tight junction stability. However, potential adverse effects such as acting as prooxidants, or perturbations of efflux transporters and phase I/II metabolizing enzymes, with increased uptake of undesired xenobiotics, should also be considered. In this review, we summarize current knowledge around preventive and arbitrary actions of polyphenols targeting IBD.

Dietary Supplementation with a Low Dose of Polyphenol-Rich Grape Pomace Extract Prevents Dextran Sulfate Sodium-Induced Colitis in Rats

Evidence from several epidemiological and experimental studies points to a beneficial role of dietary polyphenols in inflammatory bowel disease. In this study, we investigate the protective effect of dietary supplementation with various amounts of a polyphenol-rich grape pomace extract (GPE) on the development of dextran sulfate sodium (DSS)-induced colitis in rats. Rats were fed 21 days on a semisynthetic diet enriched with GPE (0.1%, 0.5%, and 1%), and acute colitis was induced by DSS (40 g/L in the drinking water) administration during the last 7 days. The low GPE content in the diet (0.1%) attenuated clinical signs and colon shortening and limited DSS-induced histological lesions. GPE 0.1% also attenuated the DSS-induced increase in myeloperoxidase activity and improved superoxide dismutase activity. Higher amounts of GPE in the diet induced only weak and nonsignificant protective effects. These results suggest that consumption of a low amount of polyphenol-rich GPE helps protect against colitis development.

Metabolic and Microbial Modulation of the Large Intestine Ecosystem by Non-Absorbed Diet Phenolic Compounds: A Review

Phenolic compounds represent a diverse group of phytochemicals whose intake is associated with a wide spectrum of health benefits. As consequence of their low bioavailability, most of them reach the large intestine where, mediated by the action of local microbiota, a series of related microbial metabolites are accumulated. In the present review, gut microbial transformations of non-absorbed phenolic compounds are summarized. Several studies have reached a general consensus that unbalanced diets are associated with undesirable changes in gut metabolism that could be detrimental to intestinal health. In terms of explaining the possible effects of non-absorbed phenolic compounds, we have also gathered information regarded their influence on the local metabolism. For this purpose, a number of issues are discussed. Firstly, we consider the possible implications of phenolic compounds in the metabolism of colonic products, such as short chain fatty acids (SCFA), sterols (cholesterol and bile acids), and microbial products of non-absorbed proteins. Due to their being recognized as affective antioxidant and anti-inflammatory agents, the ability of phenolic compounds to counteract or suppress pro-oxidant and/or pro-inflammatory responses, triggered by bowel diseases, is also presented. The modulation of gut microbiota through dietetic maneuvers including phenolic compounds is also commented on. Although the available data seems to assume positive effects in terms of gut health protection, it is still insufficient for solid conclusions to be extracted, basically due to the lack of human trials to confirm the results obtained by the in vitro and animal studies. We consider that more emphasis should be focused on the study of phenolic compounds, particularly in their microbial metabolites, and their power to influence different aspects of gut health.