A lyophilized red grape pomace containing proanthocyanidin-rich dietary fiber induces genetic and metabolic alterations in colon mucosa of female C57BL/6J mice

Adipose tissue inflammation linked to obesity: A review of current understanding, therapies and relevance of phyto-therapeutics

Obesity is a current global challenge affecting all ages and is characterized by the up-regulated secretion of bioactive factors/pathways which result in adipose tissue inflammation (ATI). Current obesity therapies are mainly focused on lifestyle (diet/nutrition) changes. This is because many chemosynthetic anti-obesogenic medications cause adverse effects like diarrhoea, dyspepsia, and faecal incontinence, among others. As such, it is necessary to appraise the efficacies and mechanisms of action of safer, natural alternatives like plant-sourced compounds, extracts [extractable phenol (EP) and macromolecular antioxidant (MA) extracts], and anti-inflammatory peptides, among others, with a view to providing a unique approach to obesity care. These natural alternatives may constitute potent therapies for ATI linked to obesity. The potential of MA compounds (analysed for the first time in this review) and extracts in ATI and obesity management is elucidated upon, while also highlighting research gaps and future prospects. Furthermore, immune cells, signalling pathways, genes, and adipocyte cytokines play key roles in ATI responses and are targeted in certain therapies. As a result, this review gives an in-depth appraisal of ATI linked to obesity, its causes, mechanisms, and effects of past, present, and future therapies for reversal and alleviation of ATI. Achieving a significant decrease in morbidity and mortality rates attributed to ATI linked to obesity and related comorbidities is possible as research improves our understanding over time.

Unraveling the bioactive interplay: seaweed polysaccharide, polyphenol and their gut modulation effect

Seaweed is rich in many unique bioactive compounds such as polyphenols and sulfated polysaccharides that are not found in terrestrial plant. The discovery of numerous biological activities from seaweed has made seaweed an attractive functional food source with the potential to be exploited for human health benefits. During food processing and digestion, cell wall polysaccharide and polyphenols commonly interact, and this may influence the nutritional properties of food. Interactions between cell wall polysaccharide and polyphenols in plant-based system has been extensively studied. However, similar interactions in seaweed have received little attention despite the vast disparity between the structural and chemical composition of plant and seaweed cell wall. This poses a challenge in extracting seaweed bioactive compounds with intact biological properties. This review aims to summarize the cell wall polysaccharide and polyphenols present in brown, red and green seaweed, and current knowledge on their potential interactions. Moreover, this review gives an overview of the gut modulation effect of seaweed polysaccharide and polyphenol.

Profiling of hepatic transcriptomes reveals modulatory effects of parasitic infection on the metabolic response to dietary polyphenols in pigs

Polyphenols are a class of bioactive plant compounds with health-promoting properties, however the interactions between polyphenols and pathogen infection and their cumulative impact on inflammation and metabolic health are not well understood. Here, we investigated if a sub-clinical parasitic infection modulates the hepatic response to dietary polyphenol supplementation in a porcine model. Pigs were fed a diet with or without 1% grape proanthocyanidin (PAC) for 28 days. During the final 14 days of the experiment, half the pigs in each dietary group were inoculated with the parasitic nematode Ascaris suum. Serum biochemistry was measured and hepatic transcriptional responses were determined by RNA-sequencing coupled with gene-set enrichment analysis. A. suum infection resulted in reduced serum phosphate, potassium and calcium, and increased serum iron concentrations. In uninfected pigs, PAC supplementation markedly changed the liver transcriptome including genes related to carbohydrate and lipid metabolism, insulin signaling, and bile acid synthesis. However, during A. suum infection, a separate set of genes were modulated by dietary PAC, indicating that the polyphenol-mediated effects were dependent on infection status. A. suum infection strongly influenced the expression of genes related to cellular metabolism, and, in contrast to the effects of PAC, these changes were mostly identical in both control-fed and PAC-fed pigs. Thus, the hepatic response to infection was mostly unaffected by concurrent polyphenol intake. We conclude that the presence of a commonly occurring parasite substantially influences the outcome of dietary polyphenol supplementation, which may have important relevance for nutritional interventions in populations where intestinal parasitism is widespread.

Polyphenols from food by-products: An alternative or complementary therapy to IBD conventional treatments

Inflammatory bowel diseases (IBD) are illnesses characterized by chronic intestinal inflammation and microbial dysbiosis that have emerged as a public health challenge worldwide. It comprises two main conditions: Crohn's disease and ulcerative colitis. Currently, conventional therapy to treat IBD are not free from side effects, such as liver and kidney toxicity, drug resistance, and allergic reactions. In view of this, there is growing research for alternative and complementary therapies that, in addition to acting in the prevention or the control of the disease, do not compromise the quality of life and health of individuals. In this sense, a growing body of evidence has confirmed the benefits of natural phenolic compounds in intestinal health. Phenolic compounds or polyphenols are molecules widely distributed throughout the plant kingdom (flowers, vegetables, leaves, and fruits), including plant materials remaining of the handling and food industrial processing, referred to in the scientific literature as by-products, food waste, or bagasse. Since by-products are low-cost, abundant, easily accessible, safe, and rich in bioactive compounds, it becomes an exciting option to extract, concentrate or isolate phenolic compounds to be posteriorly applied in the therapeutic approach of IBD. In this article, we have reviewed the main phenolic compounds present in various plants and by-products that have shown beneficial and/or promising effects in experimental pre-clinical, clinical, and in vitro research with IBD. In addition, we have mentioned and suggested several plants and by-products originated and produced in Latin America that could be part of future research as good sources of specific phenolic compounds to be applied in the prevention and development of alternative treatments for IBD. This review may offer a valuable reference for studies related to IBD administering phenolic compounds from natural, cheap, and easily accessible raw and undervalued materials.

Effect of melatonin on visceral fat deposition, lipid metabolism and hepatic lipo-metabolic gene expression in male rats

Melatonin (MT) influences lipid metabolism in animals; however, the mechanistic effect of melatonin on liver fat and abdominal adipose deposition requires further clarity. In order to study the effects of melatonin on lipid metabolism, and hepatic fat and abdominal adipose deposition in animals, twenty Sprague-Dawley (SD) rats of 6 weeks of age with similar bodyweight were randomly divided into two groups: control (CTL) and MT-treated (10 mg/kg/day). During a 60-day experiment, food intake and bodyweight were measured daily and weekly respectively. At the end of treatment, blood samples were collected to collect plasma to quantify hormones and metabolic indicators of lipid metabolism. In addition, organ and abdominal adipose depots including liver, and omental, perirenal, and epididymal fat were weighed. Liver tissue was sampled for sectioning, long-chain fatty acid (LCFA) quantification, and gene chip and Real-time quantitative PCR (qPCR) analyses. The results showed that liver weight and index (ratio of liver weight to body weight) in MT group reduced by 20.69% and 9.63% respectively; omentum weight and index reduced by 59.88% and 54.93% respectively, and epididymal fat weight reduced by 45.34% (p = 0.049), relative to CTL. Plasma lipid indices, triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL) and total cholesterol (TC) with MT treatment decreased significantly compared with the control. Fat and 8 LCFA content in liver in MT group also decreased. Gene chip and qPCR demonstrated that there were 289 genes up-regulated and 293 genes down-regulated by MT. Further analysis found that the mRNA expression of lipolysis-related genes increased, while the mRNA expression of lipogenesis-related enzymes decreased (p < 0.05) with MT. This study concluded that melatonin greatly affected fat deposition, and hepatic LCFA supply and the expression of genes associated with lipogenesis and lipolysis.

The Impact of Whole Grain Intake on Gastrointestinal Tumors: A Focus on Colorectal, Gastric, and Esophageal Cancers

Cereals are one of staple foods in human diet, mainly consumed as refined grains. Nonetheless, epidemiological data indicate that whole grain (WG) intake is inversely related to risk of type 2 diabetes, cardiovascular disease, and several cancer types, as well as to all-cause mortality. Particularly responsive to WG positive action is the gastrointestinal tract, daily exposed to bioactive food components. Herein, we shall provide an up-to-date overview on relationship between WG intake and prevention of gastrointestinal tumors, with a particular focus on colorectal, stomach, and esophagus cancers. Unlike refined counterparts, WG consumption is inversely associated with risk of these gastrointestinal cancers, most consistently with the risk of colorectal tumor. Some WG effects may be mediated by beneficial constituents (such as fiber and polyphenols) that are reduced/lost during milling process. Beside health-promoting action, WGs are still under-consumed in most countries; therefore, World Health Organization and other public/private stakeholders should cooperate to implement WG consumption in the whole population, in order to reach nutritionally effective intakes.

Non-Extractable Polyphenols from Food By-Products: Current Knowledge on Recovery, Characterisation, and Potential Applications

Non-extractable polyphenols (NEPs), or bound polyphenols, are a significant fraction of polyphenols that are retained in the extraction residues after conventional aqueous organic solvent extraction. They include both high molecular weight polymeric polyphenols and low molecular weight phenolics attached to macromolecules. Current knowledge proved that these bioactive compounds possess high antioxidant, antidiabetic, and other biological activities. Plant-based food by-products, such as peels, pomace, and seeds, possess high amount of NEPs. The recovery of these valuable compounds is considered an effective way to recycle food by-products and mitigate pollution, bad manufacturing practice, and economic loss caused by the residues management. The current challenge to valorise NEPs from plant-based by-products is to increase the extraction efficiency with proper techniques, choose appropriate characterising methods, and explore potential functions to use in some products. Based on this scenario, the present review aims to summarise the extraction procedure and technologies applied to recover NEPs from plant-based by-products. Furthermore, it also describes the main techniques used for the characterisation of NEPs and outlines their potential food, pharmaceutical, nutraceutical, and cosmetic applications.

The Protective Effect of Polyphenols for Colorectal Cancer

Colorectal cancer (CRC) is one of the most prevalent cancers that threaten people in many countries. It is a multi-factorial chronic disease caused by a combination of genetic and environmental factors, but it is mainly related to lifestyle factors, including diet. Plentiful plant foods and beverages are abundant in polyphenols with antioxidant, anti-atherosclerotic, anti-inflammatory, and anticancer properties. These compounds participate in host nutrition and disease pathology regulation in different ways. Polyphenolic compounds have been used to prevent and inhibit the development and prognosis of cancer, and examples include green tea polyphenol (-)epigallocatechin-3-O-gallate (EGCG), curcumin, and resveratrol. Of course, there are more known and unknown polyphenol compounds that need to be further explored for their anticancer properties. This article focuses on the fact that polyphenols affect the progression of CRC by controlling intestinal inflammation, epigenetics, and the intestinal microbe in the aspects of prevention, treatment, and prognosis.

Antioxidant, Anti-Inflammatory and Antiproliferative Effects of the Vitis vinifera L. var. Fetească Neagră and Pinot Noir Pomace Extracts

The pathophysiology of inflammation and oxidative stress generated during different types of cancers and anticancer treatments is well documented. Traditionally, grape pomace is used for animal feed, organic fertilizers, ethanol production or is disposed as waste. Because grape pomace is a rich source of antioxidant compounds, the purpose of the study was to evaluate the antioxidant, anti-inflammatory, and antiproliferative effects of fresh and fermented grape pomace extracts of two Vitis vinifera L. varieties Fetească neagră and Pinot noir cultivated in Romania. Firstly, grape pomace phytochemical analysis and in vitro antioxidant tests were performed. Secondly, the effect of a seven-day pretreatment with grape pomace extracts on the turpentine oil-induced inflammation in rats was assessed by measuring total oxidative status, total antioxidant response, oxidative stress index, malondialdehyde, total thiols, nitric oxide and 3-nitrotyrosine. Thirdly, the antiproliferative properties were evaluated on human lung carcinoma (A549), human breast adenocarcinoma (MDA-MB-231), murine melanoma (B164A5), and keratinocyte (HaCat) cell lines. Fetească neagră and Pinot noir grape pomace extracts have a rich content of polyphenols and in vitro antioxidant effect. Fermented samples had higher polyphenol content, but fresh samples had better antioxidant activity. Pretreatment with grape pomace extracts reduced inflammation-induced oxidative stress in a concentration-dependent way, fresh samples being more efficient. The malignant cells' proliferation was inhibited by all grape pomace extracts, fermented Fetească neagră extracts having the strongest effect. Conclusion: fresh and fermented pomace extracts of Vitis vinifera L. varieties Fetească neagră and Pinot noir cultivated in a Romanian wine region have antioxidant, anti-inflammatory and antiproliferative effects.

Grape peel powder attenuates the inflammatory and oxidative response of experimental colitis in rats by modulating the NF-κB pathway and activity of antioxidant enzymes

Most phenolic compounds and dietary fiber reach intact to the colon. We hypothesized that grape peel powder (GPP), a rich source of these bioactive compounds, modulates inflammatory and oxidative pathways collaborating to attenuate colonic damage in experimental colitis. To determine which bioactive fraction would be responsible for this effect, the aim of this study was to evaluate the effect of dietary supplementation with whole GPP or the isolated bioactive-rich fractions from GPP (extractable polyphenols [EP], dietary fiber and fiber-bound polyphenols [NEP-F], and dietary fiber) in rats with experimental colitis. Colitis was induced by intrarectal injection of 2,4,6-trinitrobenzene sulfonic acid (TNBS) after 15 days of dietary supplementation. EP diet did not reverse the decrease in feed intake and indeed worsened colon shortening and increased spleen weight; however, these effects were not observed for the GPP group, which had polyphenols associated to the matrix besides the extractable ones. Colitis impaired the activity of colonic antioxidant enzymes and increased lipid peroxidation, protein oxidation, nitric oxide (NO) levels, and proinflammatory cytokines in serum and in the colon tissue. GPP restored the activity of antioxidant enzymes and decreased colon oxidation and NO levels. All grape peel fractions reduced the protein expression of the inhibitor of kappa kinase beta and NO levels in colon tissue, but only NEP-F reduced the expression of phosphorylated nuclear factor kappa B and myeloperoxidase activity. Results demonstrated that GPP attenuates inflammatory and oxidative response in TNBS-induced colitis by downregulating the nuclear factor kappa B pathway and upregulating antioxidant enzymes, with NEP-F being the fraction most likely associated to these protective effects.

Effects of co-administered melatonin, fructose and bisphenol A (BPA) on rat epididymis and sperm characteristics

Consumption of fructose-rich food and exposure to endocrine disrupting chemicals continue to increase. High fructose consumption is associated with increased incidence of dyslipidemia, hypertension, hyperuricemia and insulin resistance. Bisphenol A (BPA) is an environmental contaminant that exhibits estrogen-like activity; it impairs reproductive organs, sperm production, spermatogenesis and fertility. We investigated the possible ameliorative effects of melatonin on rat epididymis and sperm characteristics following exposure to fructose and BPA. We used 42 adult male Sprague-Dawley rats divided into seven groups. Group 1, control group, was treated with 25 mg/kg sesame oil + 25 mg/kg 0.1% ethanol. Group 2 was treated with 10% aqueous fructose. Group 3 was treated with 25 mg/kg BPA. Group 4 was treated with 10% fructose and 25 mg/kg BPA. Group 5 was treated with 10% fructose and 20 mg/kg melatonin. Group 6 was treated with 25 mg/kg BPA and 20 mg/kg melatonin. Group 7 was treated with 10% fructose, 25 mg/kg BPA and 20 mg/kg melatonin. After 60 days, epididymal tissue was removed and analyzed using histochemistry and immunohistochemistry. Sperm were counted, and sperm motility and viability were investigated. Administration of BPA caused significant damage to both epididymal tissue and sperm quality; melatonin reduced the damage, but did not prevent it completely.

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.

DNA Microarray-Based Screening and Characterization of Traditional Chinese Medicine

The application of DNA microarray assay (DMA) has entered a new era owing to recent innovations in omics technologies. This review summarizes recent applications of DMA-based gene expression profiling by focusing on the screening and characterizationof traditional Chinese medicine. First, herbs, mushrooms, and dietary plants analyzed by DMA along with their effective components and their biological/physiological effects are summarized and discussed by examining their comprehensive list and a list of representative effective chemicals. Second, the mechanisms of action of traditional Chinese medicine are summarized by examining the genes and pathways responsible for the action, the cell functions involved in the action, and the activities found by DMA (silent estrogens). Third, applications of DMA for traditional Chinese medicine are discussed by examining reported examples and new protocols for its use in quality control. Further innovations in the signaling pathway based evaluation of beneficial effects and the assessment of potential risks of traditional Chinese medicine are expected, just as are observed in other closely related fields, such as the therapeutic, environmental, nutritional, and pharmacological fields.

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

BACKGROUND

Several studies have reported that polyphenols may exert beneficial effects on inflammatory bowel disease. This study aimed to evaluate the effects of preventive consumption of polyphenol-rich red grape pomace extracts (GPEs) on dextran sulfate sodium (DSS)-induced colitis in rats. Rats were fed for 21 days with a semi-synthetic diet enriched with a GPE (Alicante-S, Alicante-P or Pinot-S) and colitis was induced by DSS administration in drinking water (40 g L(-1) ) during the last 7 days of experimentation.

RESULTS

GPEs attenuated clinical signs and colon shortening and Alicante GPEs limited histological lesions induced by DSS. GPEs curbed the increase in myeloperoxidase activity and modulated antioxidant enzyme activities. Moreover, GPEs prevented the DSS-induced increase in pro-inflammatory cytokine levels and the up-regulation of various genes implicated in colitis such as intercellular adhesion molecule 1 (ICAM-1) and matrix metalloproteinase 9 (MMP-9).

CONCLUSION

These results suggest that polyphenol-rich red GPEs could provide prevention against colon inflammation.

Chemopreventive and Therapeutic Effects of Edible Berries: A Focus on Colon Cancer Prevention and Treatment

Colon cancer is one of the most prevalent diseases across the world. Numerous epidemiological studies indicate that diets rich in fruit, such as berries, provide significant health benefits against several types of cancer, including colon cancer. The anticancer activities of berries are attributed to their high content of phytochemicals and to their relevant antioxidant properties. In vitro and in vivo studies have demonstrated that berries and their bioactive components exert therapeutic and preventive effects against colon cancer by the suppression of inflammation, oxidative stress, proliferation and angiogenesis, through the modulation of multiple signaling pathways such as NF-κB, Wnt/β-catenin, PI3K/AKT/PKB/mTOR, and ERK/MAPK. Based on the exciting outcomes of preclinical studies, a few berries have advanced to the clinical phase. A limited number of human studies have shown that consumption of berries can prevent colorectal cancer, especially in patients at high risk (familial adenopolyposis or aberrant crypt foci, and inflammatory bowel diseases). In this review, we aim to highlight the findings of berries and their bioactive compounds in colon cancer from in vitro and in vivo studies, both on animals and humans. Thus, this review could be a useful step towards the next phase of berry research in colon cancer.

Contribution of Macromolecular Antioxidants to Dietary Antioxidant Capacity: A Study in the Spanish Mediterranean Diet

Epidemiological and clinical studies show that diets with a high antioxidant capacity, such us those rich in plant food and beverages, are associated with significant decreases in the overall risk of cardiovascular disease or colorectal cancer. Current studies on dietary antioxidants and dietary antioxidant capacity focus exclusively on low molecular weight or soluble antioxidants (vitamins C and E, phenolic compounds and carotenoids), ignoring macromolecular antioxidants. These are polymeric phenolic compounds or polyphenols and carotenoids linked to plant food macromolecules that yield bioavailable metabolites by the action of the microbiota with significant effects either local and/or systemic after absorption. This study determined the antioxidant capacity of the Spanish Mediterranean diet including for the first time both soluble and macromolecular antioxidants. Antioxidant capacity and consumption data of the 54 most consumed plant foods and beverages were used. Results showed that macromolecular antioxidants are the major dietary antioxidants, contributing a 61% to the diet antioxidant capacity (8000 μmol Trolox, determined by ABTS method). The antioxidant capacity data for foods and beverages provided here may be used to estimate the dietary antioxidant capacity in different populations, where similar contributions of macromolecular antioxidants may be expected, and also to design antioxidant-rich diets. Including macromolecular antioxidants in mechanistic, intervention and observational studies on dietary antioxidants may contribute to a better understanding of the role of antioxidants in nutrition and health.

Chemopreventive Action of Anthocyanin-rich Black Soybean Fraction in APC (Min/+) Intestinal Polyposis Model

BACKGROUND

Anthocyanins have been shown to inhibit cancer cell growth by suppressing oxidative stress and inflammatory responses. The purpose of this study was to investigate the effects of an anthocyanin-rich extract (AE) from black soybean coat on intestinal carcinogenesis.

METHODS

Apc (Min/+) mice were fed a diet of 0.2% or 0.5% AE for 7 weeks. We analyzed the number of intestinal tumors, oxidative stress and inflammatory markers associated with β-catenin and cytosolic phospholipase A2 (cPLA2) signals. The number of intestinal tumors, and cellular expression of β-catenin were determined.

RESULTS

The number of intestinal tumors was significantly lower in mice fed a 0.5% AE diet compared to those of the other groups. Cytosolic β-catenin expression was significantly decreased in the AE supplemented groups compared to that of the control animals. In addition, mucosa expression of cyclooxygenase-2 and cPLA2 were also significantly decreased in the 0.5% AE group, by 32% and 62%, respectively, compared to the control group.

CONCLUSIONS

These results suggest that dietary AE reduced the development of intestinal tumors, possibly through the ability to suppress oxidative stresses, decreasing inflammatory responses mediated by β-catenin associated signals.

Evaluation of subacute bisphenol - A toxicity on male reproductive system

AIM

The aim was to evaluate the effect of multiple oral administration of bisphenol A (BPA) for 28 days on seminal characteristic on mammal using Wistar rat as a model.

MATERIALS AND METHODS

Rats were randomly divided into five different groups having 6 male rats in each group. The doses chosen were 50, 200, and 600 mg/kg body weight for Groups III, IV and V, respectively, based on preliminary dose range finding study and Group II served as vehicle control and Group I was negative control.

RESULTS

Reproductive study in the BPA-treated rats on day 28 revealed that there was significant (p≤0.05) reduction in the epididymal sperm count of rats of Group IV and significant (p≤0.01) decrease in Group V. Sperm motility percentage, dead count percentage, head and tail abnormality percentage were found to be significantly (p≤0.01) increased in rats of BPA-treated groups as compared to rats of control groups. Testes showed necrosis of germinal layer and spermatogonial cells in the seminiferous tubules. Hematological examination revealed significant (p≤0.01) decrease in the mean values of total erythrocyte count (TEC), total leukocyte count (TLC), hemoglobin, packed cell volume, and there was also significant (p≤0.05) lymphocytopenia in treated animals.

CONCLUSION

It can be concluded from this study that subacute toxicity of BPA caused a reduction in the epididymal sperm count, sperm motility, dead count, head and tail abnormality, as well as hematological indices such as TLC, TEC etc. Hence, it appears that BPA affects the germ cells leading to impairment in the spermatogenesis, and thus having its property as reproductive toxicant and it also suppresses bone marrow functioning, which leads to normocytic hypochromic anemia in rats.

Dietary fiber and phenolic compounds as functional ingredients: interaction and possible effect after ingestion

Dietary fiber and phenolic compounds are two recognized dietary factors responsible for potential effects on human health; therefore, they have been widely used to increase functionality of some foods. This paper focuses on showing the use of both substances as functional ingredients for enriching foods, and at the same time, describes the use of a single material that combines the properties of the two types of substances. The last part of the work describes some facts related to the interaction between dietary fiber and phenolic compounds, which could affect the bioaccessibility and absorption of phenolics in the gut. In this sense, the purpose of the present review is to compile and analyze evidence relating to the use of dietary fiber and phenolic compounds to enhance technological and nutritional properties of foods and hypothesize some of the possible effects in the gut after their ingestion.

Long-term intake of pea fiber affects colonic barrier function, bacterial and transcriptional profile in pig model

The objective of this study was to investigate the effect of long-term intake of pea fiber (PF) on colonic health and the underlying mechanism. Fifty weaned piglets were randomly allocated into 2 groups receiving control and fibrous diet with inclusion of PF from weaning to Day 160 postweaning, with 5 pens in each group and 5 pigs in each pen. Compared with control diet, long-term intake of PF diet induced deeper crypt and increased colonic barrier-related protein expression of mucin and sIgA. As indicated by the increased lactobacillus content, pigs fed PF diet had a stimulating effect on bacterial fermentation in the colon, thus a higher concentration of colonic total short chain fatty acid and acetic acid were observed. DNA microarray results suggested that feeding PF diet inhibited 77% of genes (40 downregulated and 12 upregulated genes) related to colonic cancer, immune response, and lipid metabolism, involving in signal pathway such as intestinal immune network for IgA production, peroxisome proliferator-activated receptor signaling pathway and nutrient metabolism-related pathways. Collectively, our results suggested that long-term intake of PF would improve colonic function via altering colonic barriers, colonic immune and metabolism-related protein or gene expressions.

Non-extractable polyphenols, a major dietary antioxidant: occurrence, metabolic fate and health effects

Current research on dietary antioxidants misses the so-called non-extractable polyphenols (NEPP), which are not significantly released from the food matrix either by mastication, acid pH in the stomach or action of digestive enzymes, reaching the colon nearly intact. NEPP, not detected by the usual analytical procedures, are made up of macromolecules and single phenolic compounds associated with macromolecules. Therefore, NEPP are not included in food and dietary intake data nor in bioavailability, intervention or observational studies. The present paper aims to provide an overview of dietary NEPP - nature, occurrence in diet, metabolic fate and possible health effects. NEPP are a relevant fraction of dietary polyphenols exerting their main biological action in the colon, where they are extensively fermented by the action of microbiota, giving place to absorbable metabolites. NEPP exhibit different potential health-related properties, in particular in relation to gastrointestinal health, such as increases in antioxidant and antiproliferative capacities, reduction of intestinal tumorigenesis and modification of gene expression, as observed in different animal models. Further research into NEPP may provide a better understanding of the health effects of dietary antioxidants.

Concept and health-related properties of nonextractable polyphenols: the missing dietary polyphenols

Most research studies in the field of dietary polyphenols or phenolic compounds use a chemical approach focusing exclusively on polyphenols extracted from plant foods with organic solvents. However, an appreciable part of polyphenols are not extracted with organic solvents and thus are ignored in biological, nutritional, and epidemiological studies. Recent studies have shown that these nonextractable polyphenols (NEPP) are a major part of total dietary polyphenols and that they exhibit a significant biological activity. A physiological approach is proposed on the basis that the bioavailability and health-related properties of polyphenols depend on their solubility in intestinal fluids, which is different from their solubility in organic solvents. This paper tries to clarify the concept of NEPP, distinguishing between chemical and physiological approaches and pointing out the main qualitative and quantitative differences between them. It is stressed that the literature and databases refer to only extractable polyphenols. Greater attention to NEPP may fill the current gap in the field of dietary polyphenols.

Suppression of lipopolysaccharide and galactosamine-induced hepatic inflammation by red grape pomace

Grape pomace is generated in the production process of wine and grape juices and is an industrial waste. This study investigated whether an intake of grape pomace was able to suppress chronic inflammation induced by lipopolysaccharide (LPS) and galactosamine (GalN) in vivo. When Sprague-Dawley rats were orally given methanolic extracts from red and white grape pomace, the extracts inhibited the LPS/GalN-evoked activation of nuclear factor-κB (NF-κB) dose-dependently, and red grape pomace exerted a stronger effect than white grape one. Next, rats were fed an AIN93 M-based diet containing 5% red grape pomace for 7 days, followed by the intraperitoneal injection of LPS and GalN. The intake of the red grape pomace-supplemented diet was found to suppress the LPS/GalN-induced activation of NF-κB and expression of inducible nitric oxide synthase and cyclooxygenase-2 proteins. These results suggest that red grape pomace may contain an abundance of effective compound(s) for anti-inflammatory action.