Castanea sativa Mill. By-Products: Investigation of Potential Anti-Inflammatory Effects in Human Intestinal Epithelial Cells.

Castanea sativa Mill. (C. sativa) processing and pruning generate several by-products, including leaves, burs, and shells (inner and outer teguments), which are considered an important source of high-value phytochemicals. Ellagitannins from C. sativa leaf extracts have been described to impair H. pylori viability and inflammation in gastric cells. Furthermore, chestnut shells showed an important anti-inflammatory effect in gastric epithelial cells. Dietary polyphenols, including tannins, have been reported to interfere with targets of inflammation, including the nuclear factor κB (NF-κB). A promising role as a further therapeutical target for gut disorders has been recently proposed for the regulatory subunit of hypoxia-inducible factor (HIF-1α), as a potential stabilizer of intestinal barrier integrity. Therefore, the main objective of this work is the chemical characterization of several chestnut by-products (bud, spiny bur, wood, pericarp and episperm), together with the exploitation of their anti-inflammatory properties in intestinal cells, scavenging capacity, and stability following gastrointestinal digestion. The chemical characterization confirmed the presence of bioactive polyphenols in the extracts, including ellagitannins. In CaCo-2 cells stimulated by an IL-1ß-IFN-γ cocktail, nearly all chestnut by-products (50 µg/mL) inhibited the release of proinflammatory mediators (CXCL-10, IL-8, MCP-1, ICAM), along with the NF-κB-driven transcription, and induced the HRE-driven transcription. The stability of the most promising extracts, identified through PCA and cluster analysis, was addressed by in vitro gastrointestinal digestion. Despite the significant reduction in total polyphenol index of chestnut bud and wood after gastric and intestinal digestion, the activity of these extracts on both scavenging and anti-inflammatory parameters remained promising. These data contribute to exploit the potential of chestnut by-products as sources of dietary polyphenols with anti-inflammatory properties at the intestinal level. Moreover, this study could represent an important step to encourage the recycling and valorization of chestnut by-products, promoting the circular economy and reducing the environmental impact related to the management of agriculture waste.

Resveratrol, human health and winemaking perspectives.

Resveratrol, (3, 5, 4'-trihydroxystilbene) is a non-flavonoid polyphenol stilbene synthesized by plants when damaged by infectious diseases or ionizing radiation. Although present in more than seventy plant species, grapes and wine are the major dietary contributors of resveratrol, responsible for 98% of the daily intake. In 1992, Renaud and De Lorgeril first linked wine polyphenols, including resveratrol, to the potential health benefits ascribed to regular and moderate wine consumption (the so called "French Paradox"). Since then, resveratrol has received increasing scientific interest, leading to research on its biological actions, and to a large number of published papers, which have been collected and discussed in this review. The relatively low amounts of resveratrol measured in wine following moderate consumption, however, may be insufficient to mitigate biological damage, such as that due to oxidative stress. On this basis, the authors also highlight the importance of viticulture and the winemaking process to enhance resveratrol concentrations in wine in order to bolster potential health benefits.

A bio-guided approach for the development of a chestnut-based proanthocyanidin-enriched nutraceutical with potential anti-gastritis properties.

Gastritis is a widely spread inflammatory disease, mostly caused by Helicobacter pylori infection. Release of IL-8 by the stomach epithelium is a hallmark of gastritis and contributes to the amplification of the inflammatory state. Pharmacological modulation of IL-8 release is a strategy to relieve gastric inflammation and prevent more severe clinical outcomes. In search of nutraceuticals with potential anti-gastritis properties we used a bio-guided approach based on IL-8 secretion by gastric cells to characterize extracts from the fruits of different chestnut varieties. We found that the ability to inhibit IL-8 secretion correlated with the amount of proanthocyanidins and was associated to the not edible parts of chestnut in all the tested varieties. We also found that the anti-inflammatory activity is preserved upon mild thermal treatment and after in vitro simulated gastric digestion. By combining a robust bio-guided approach with a comprehensive analysis of the tannin fraction of chestnut extracts, we provide evidence for the potential use of chestnut-based nutraceuticals in human gastritis. The bioactive components of chestnut fruits inhibit IL-8 secretion by impairing NF-κB signaling and by other mechanisms, thus opening new applications of proanthocyanidins for inflammation-based diseases.

Adverse Effects of Plant Food Supplements and Plants Consumed as Food: Results from the Poisons Centres-Based PlantLIBRA Study.

Plant food supplements (PFS) are products of increasing popularity and wide-spread distribution. Nevertheless, information about their risks is limited. To fill this gap, a poisons centres-based study was performed as part of the EU project PlantLIBRA. Multicentre retrospective review of data from selected European and Brazilian poisons centres, involving human cases of adverse effects due to plants consumed as food or as ingredients of food supplements recorded between 2006 and 2010. Ten poisons centres provided a total of 75 cases. In 57 cases (76%) a PFS was involved; in 18 (24%) a plant was ingested as food. The 10 most frequently reported plants were Valeriana officinalis, Camellia sinensis, Paullinia cupana, Melissa officinalis, Passiflora incarnata, Mentha piperita, Glycyrrhiza glabra, Ilex paraguariensis, Panax ginseng, and Citrus aurantium. The most frequently observed clinical effects were neurotoxicity and gastro-intestinal symptoms. Most cases showed a benign clinical course; however, five cases were severe. PFS-related adverse effects seem to be relatively infrequent issues for poisons centres. Most cases showed mild symptoms. Nevertheless, the occurrence of some severe adverse effects and the increasing popularity of PFS require continuous active surveillance, and further research is warranted. Copyright © 2016 John Wiley & Sons, Ltd.

Evaluation of the Anti-Inflammatory Activity of Raisins (Vitis vinifera L.) in Human Gastric Epithelial Cells: A Comparative Study.

Raisins (Vitis vinifera L.) are dried grapes largely consumed as important source of nutrients and polyphenols. Several studies report health benefits of raisins, including anti-inflammatory and antioxidant properties, whereas the anti-inflammatory activity at gastric level of the hydro-alcoholic extracts, which are mostly used for food supplements preparation, was not reported until now. The aim of this study was to compare the anti-inflammatory activity of five raisin extracts focusing on Interleukin (IL)-8 and Nuclear Factor (NF)-κB pathway. Raisin extracts were characterized by High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD) analysis and screened for their ability to inhibit Tumor necrosis factor (TNF)α-induced IL-8 release and promoter activity in human gastric epithelial cells. Turkish variety significantly inhibited TNFα-induced IL-8 release, and the effect was due to the impairment of the corresponding promoter activity. Macroscopic evaluation showed the presence of seeds, absent in the other varieties; thus, hydro-alcoholic extracts from fruits and seeds were individually tested on IL-8 and NF-κB pathway. Seed extract inhibited IL-8 and NF-κB pathway, showing higher potency with respect to the fruit. Although the main effect was due to the presence of seeds, the fruit showed significant activity as well. Our data suggest that consumption of selected varieties of raisins could confer a beneficial effect against gastric inflammatory diseases.

Molecular characterization of allergens in raw and processed kiwifruit.

BACKGROUND: The prevalence of allergy to kiwifruit is increasing in Europe since the last two decades. Different proteins have been identified as kiwifruit allergens; even though with geographic differences, Act d 1, a cysteine protease protein of 30 kDa, and Act d 2, a thaumatin-like protein of 24 kDa, are normally considered the most important. The aim of this study was (i) to identify at molecular level the sensitization pattern in a group of well-characterized patients allergic to kiwifruit and (ii) to assess the role of technological treatments on kiwifruit allergenic potential. METHODS: The differences in the pattern of antigenicity between fresh and processed kiwifruit were evaluated by both immunoelectrophoretic techniques and clinical tests. RESULTS: In the group of patients included in this study, three proteins were identified as major allergens in fresh kiwifruit, as the specific sensitization was present in ≥50% of the subjects. These proteins corresponded to actinidin (Act d 1), pectin methyl aldolase (Act d 6), and thaumatin-like protein (Act d 2). Kiwellin (Act d 5) and proteins of Bet v 1 family (Act d 8/act d 11) were also recognized as minor allergens. Immunoreactivity was totally eliminated by industrial treatments used for the production of kiwifruit strained derivative. CONCLUSIONS: In this group of allergic children, the technological treatments used in the production of kiwifruit strained product reduced drastically the allergenic potential of kiwifruit.

Adverse effects of plant food supplements and botanical preparations: a systematic review with critical evaluation of causality.

AIMS: The objective of this review was to collect available data on the following: (i) adverse effects observed in humans from the intake of plant food supplements or botanical preparations; (ii) the misidentification of poisonous plants; and (iii) interactions between plant food supplements/botanicals and conventional drugs or nutrients. METHODS: PubMed/MEDLINE and Embase were searched from database inception to June 2014, using the terms 'adverse effect/s', 'poisoning/s', 'plant food supplement/s', 'misidentification/s' and 'interaction/s' in combination with the relevant plant name. All papers were critically evaluated according to the World Health Organization Guidelines for causality assessment. RESULTS: Data were obtained for 66 plants that are common ingredients of plant food supplements; of the 492 papers selected, 402 (81.7%) dealt with adverse effects directly associated with the botanical and 89 (18.1%) concerned interactions with conventional drugs. Only one case was associated with misidentification. Adverse effects were reported for 39 of the 66 botanical substances searched. Of the total references, 86.6% were associated with 14 plants, including Glycine max/soybean (19.3%), Glycyrrhiza glabra/liquorice (12.2%), Camellia sinensis/green tea ( 8.7%) and Ginkgo biloba/gingko (8.5%). CONCLUSIONS: Considering the length of time examined and the number of plants included in the review, it is remarkable that: (i) the adverse effects due to botanical ingredients were relatively infrequent, if assessed for causality; and (ii) the number of severe clinical reactions was very limited, but some fatal cases have been described. Data presented in this review were assessed for quality in order to make the results maximally useful for clinicians in identifying or excluding deleterious effects of botanicals.

Allergenic proteins in enology: a review on technological applications and safety aspects.

Proteinaceous products are widely used as fining agents during winemaking to remove unwanted insoluble particles and undissolved microscopic particles (colloidal material) from the must or wine to improve stability. Some of them (egg white, caseinates, and fish gelatine) have allergenic potential and the presence of their residues in the final product could represent a risk for allergic individuals. Moreover, lysozyme (an egg allergen) is included among wine additives to control the fermentation processes and avoid spoiling during winemaking. The aim of this paper is to review the experimental/clinical data on the use of allergenic products in enology and the measurement of relative risk for sensitized subjects. In addition, methods developed specifically for the quantification of allergenic residues in must and wine are described.

Biochemical and immunochemical evidences supporting the inclusion of quinoa (Chenopodium quinoa Willd.) as a gluten-free ingredient.

To date, the only acceptable therapeutic approach for celiac disease (CD) is a strict elimination from the diet of gluten-containing foods, but this diet does not always guarantee an adequate nutritional intake. Pseudocereals are receiving considerable attention as interesting alternatives for the formulation of gluten-free products, and quinoa grains arise as nutritive substitutes of conventional cereals. The aim of this study was the characterization of different quinoa samples corresponding to 11 quinoa varieties, using polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE) and immunoblotting techniques to assess their suitability for celiac subjects. Some of these varieties were grown in Italy to assess if the reproduction in a new habitat can guarantee the retention of the "safe" protein pattern. None of the quinoa varieties studied presented protein bands with electrophoretic mobility comparable with those of wheat gliadins, the toxic protein for celiac subjects. All the quinoa samples showed a low binding affinity for both specific anti-gliadin antibodies and IgAs from celiac subjects, confirming that quinoa can be considered as a safe ingredient for celiac patients. However, reliable varieties should be previously selected since the immuno cross-reactivity with anti-gliadin antibodies can vary significantly.

In Vitro Insights into the Dietary Role of Glucoraphanin and Its Metabolite Sulforaphane in Celiac Disease.

Sulforaphane is considered the bioactive metabolite of glucoraphanin after dietary consumption of broccoli sprouts. Although both molecules pass through the gut lumen to the large intestine in stable form, their biological impact on the first intestinal tract is poorly described. In celiac patients, the function of the small intestine is affected by celiac disease (CD), whose severe outcomes are controlled by gluten-free dietary protocols. Nevertheless, pathological signs of inflammation and oxidative stress may persist. The aim of this study was to compare the biological activity of sulforaphane with its precursor glucoraphanin in a cellular model of gliadin-induced inflammation. Human intestinal epithelial cells (CaCo-2) were stimulated with a pro-inflammatory combination of cytokines (IFN-γ, IL-1ß) and in-vitro-digested gliadin, while oxidative stress was induced by H2O2. LC-MS/MS analysis confirmed that sulforaphane from broccoli sprouts was stable after simulated gastrointestinal digestion. It inhibited the release of all chemokines selected as inflammatory read-outs, with a more potent effect against MCP-1 (IC50 = 7.81 µM). On the contrary, glucoraphanin (50 µM) was inactive. The molecules were unable to counteract the oxidative damage to DNA (γ-H2AX) and catalase levels; however, the activity of NF-κB and Nrf-2 was modulated by both molecules. The impact on epithelial permeability (TEER) was also evaluated in a Transwell® model. In the context of a pro-inflammatory combination including gliadin, TEER values were recovered by neither sulforaphane nor glucoraphanin. Conversely, in the context of co-culture with activated macrophages (THP-1), sulforaphane inhibited the release of MCP-1 (IC50 = 20.60 µM) and IL-1ß (IC50 = 1.50 µM) only, but both molecules restored epithelial integrity at 50 µM. Our work suggests that glucoraphanin should not merely be considered as just an inert precursor at the small intestine level, thus suggesting a potential interest in the framework of CD. Its biological activity might imply, at least in part, molecular mechanisms different from sulforaphane.

Pigmented corn as a gluten-free source of polyphenols with anti-inflammatory and antioxidant properties in CaCo-2 cells.

A high number of varieties from corn (Zea mays L.) have been consumed for long time all over the world, however pigmented varieties are recently gaining renewed attention due to their beneficial effects and polyphenolic content. The natural lack of gluten makes corn suitable for consumption by celiac population, who need to control their inflammatory state through an appropriate gluten-free diet. The biological effects of polyphenols from pigmented corn are poorly investigated in the context of celiac disease. In this work, we analyzed through HPLC-DAD the phenolic composition of two Italian purple and red varieties ("Scagliolo Rosso" and "Rostrato di Rovetta", respectively) comparing their effects in human intestinal epithelial cells (CaCo-2 cells). The possible impact of gastro-intestinal digestion following oral consumption was assessed as well. The phenolic profile showed the presence of phenolic acids in both varieties, while anthocyanins were identified in Scagliolo Rosso only. After simulated digestion, the level of polyphenols did not significantly change and paralleled with an increased scavenging activity. In CaCo-2 cells, stimulated by a proinflammatory cocktail containing gliadin-derived peptides (IL-1ß, IFN-γ, digested gliadin), pigmented corn extracts inhibited the release of CXCL-10 and sICAM-1, with mechanisms partially ascribed to NF-κB impairment. At the same concentration (200 µg/mL), ROS production and catalase depletion were reverted through Nrf-2-independent mechanisms. Our data suggest that polyphenols from pigmented corns might help in controlling the inflammatory and oxidative state of people with celiac disease at intestinal level, at concentrations potentially achievable through a gluten-free diet.

Plant food supplements with anti-inflammatory properties: a systematic review (I).

Plant food supplements (PFS) receive great acceptance by European consumers. However, quality and efficacy of these products remain a question of concern. The aim of this systematic review is to summarize and critically evaluate the evidence for or against the efficacy of PFS for coping inflammatory conditions by considering epidemiological and human intervention studies. The review, which consists of two parts, considers Olea europea L., Camellia sinensis L., Vitis vinifera L., and Matricaria recutita L., which are herbal material frequently used also as food. The search retrieved 1251 publications. By applying the inclusion/exclusion criteria, the final number of papers was 91. Vitis vinifera L. showed promising results, but other trials should be performed in order to assessing the efficacy. Surprisingly, it was impossible to draw conclusions for the anti-inflammatory effect of Camellia sinensis L. as green tea. No studies were found on the leaves of Olea europea L. whereas more human trials are needed to assess the anti-inflammatory effect of olive oil. Only one study for Matricaria recutita L. was selected. In conclusion, it is advisable to conduct further studies with more homogeneous population and larger number of subjects by avoiding the heterogeneity of the herbal preparations considered.

Plant food supplements with anti-inflammatory properties: a systematic review (II).

The aim of this systematic review is to summarize the evidence for or against the efficacy of plant food supplements (PFS) for coping inflammatory conditions by considering epidemiological and human intervention studies. The review considers six botanical species commonly used as food supplements/medicinals: Urtica dioica L., Symphytum officinalis L., Calendula officinalis L., Curcuma longa L., Boswellia serrata Roxb., and Harpagophytum procumbens L. The search retrieved 579 publications. By removing the duplicates and applying the inclusion/exclusion criteria, the final number of papers was 47. No epidemiological data were found. The bibliographic search found no paper regarding the anti-inflammatory effects of Calendula officinalis L. and Symphytum officinalis L. by oral use. In spite of the long-term traditional use for inflammatory disorders, Curcuma longa L. and Harpagophytum procumbens L. warrant further investigation, whereas the efficacy of Urtica dioica L, even if the available data on hard endpoints are promising, requires other trials. Boswellia serrata Roxb. was found to be the most promising, since it shows the best efficacy for the treatment of pain/inflammatory conditions. In conclusion, it is advisable to conduct further studies with more homogeneous population and larger number of subjects by avoiding the heterogeneity of the herbal preparations considered.

Correlation between catechin content and NF-κB inhibition by infusions of green and black tea.

This study investigates whether infusions of green and black tea inhibit the NF-κB driven transcription in human epithelial gastric AGS cells. Water extracts were prepared from different brands of green and black tea available on the Italian market. Teas with or without caffeine were studied. An industrially prepared freeze-dried water extract of green tea was also tested. Catechin and caffeine contents were measured by HPLC analysis. The decrease in phenol and catechin content three months after the expiry date was also investigated. The NF-κB driven transcription and the free radical scavenger activity were inhibited, and this effect was related to catechin levels. The potency of epigallocatechin 3-gallate in inhibiting NF-κB driven transcription is so great that tea extracts low in epigallocatechin 3-gallate are still highly active. In one decaffeinated sample of green tea, the phenol and catechin content was very low, probably as a consequence of caffeine removal. The decrease in catechin levels after 3 months did not reduce the inhibition of NF-κB driven transcription by tea infusions. This is the first paper reporting the inhibitory effect of NF-κB of commercial green and black infusions at the gastric level, evaluating their stability as well.

Phenolic Profile and In Vitro Antioxidant Activity of Different Corn and Rice Varieties.

Celiac disease (CD) is an autoimmune disease. To date, the only universally recognized treatment for CD is the gluten-free diet (GFD). Despite the GFD, a state of inflammation and oxidative stress could remain at the intestinal level of celiac patients. Several components of the diet, such as phenolic compounds with known antioxidant properties, could play a protective role in the inflammatory state of patients with CD. The objective of this study was the characterization of the phenolic profile and the antioxidant capacity of pigmented cereals (rice and corn) from the Italian market and farms. Different in vitro methods were applied: Folin-Ciocalteu assay, pH differential method, DPPH assay, TEAC assay, and High-Performance Thin Layer Chromatography technique. According to the results, pigmented varieties are possible valuable sources of phenolic compounds and anthocyanins with high antioxidant activity. They could be used as alternative ingredients for the formulation of gluten-free products.

Evaluation of the Potential Anti-Inflammatory Activity of Black Rice in the Framework of Celiac Disease.

Inflammation and oxidative stress are two mechanisms involved in the pathogenesis of celiac disease (CD). Since the direct effect of gliadin on the intestinal epithelia is less studied, the aims of this study were the development of a specific cellular model based on the use of gliadin as a pro-inflammatory stimulus and the evaluation of the potential antioxidant and anti-inflammatory properties of extracts from different black rice in the framework of CD. The rice extracts were in vitro digested, characterized in terms of phenolic compounds and antioxidant capacity, and tested on Caco-2 cells to investigate their inhibitory effect on Reactive Oxygen Species, the NF-κB transcription and the CXC chemokines (sICAM-1, IL-8, and CXCL-10). In addition, the role of the extracts in modulating the activation of epithelial cells in CD was confirmed by applying the K562(S) agglutination test. The black rice extracts showed inhibitory effects on the production of the oxidative and the inflammatory mediators considered, with particular reference to lymphocyte-attracting CXCL-10 both before and after digestion. The presence of anthocyanins and their digestion metabolites may account for the observed anti-inflammatory activity after in vitro digestion. This work provided preliminary data supporting the use of black rice as a healthy food or ingredient of food supplements for celiacs.

Ancient and Modern Cereals as Ingredients of the Gluten-Free Diet: Are They Safe Enough for Celiac Consumers?

Celiac disease is an autoimmune disorder that occurs in genetically predisposed individuals after consuming prolamins from some cereals. Although the products available for celiac subjects have increased significantly in quality and quantity over the last few decades, research still focuses on identifying new ingredients to improve the nutritional, sensorial and functional qualities of gluten-free products. In terms of toxicity for people with celiac disease, there is a wide variability between ancient and modern grains. The most contradictory results are related to the role of oats in the gluten-free diet. In order to clarify the role of minor cereals (such as oat) and ancient grains in the diets of celiac patients, this review discusses recent in vitro and in vivo studies performed on those cereals for which the toxicity for celiac subjects is still controversial. According to in vivo studies, selected oat varieties could be tolerated by celiac patients. On the other hands, although some wheat-ancient grains (Triticum monococcum, Triticum aestivum ssp. spelta and Kamut®) showed a reduced in vitro toxicity, to date, these grains are still considered toxic for celiac patients. Contradictory results underline the importance of studying the safety of "unusual" cereals in more detail.

Polyphenols and Human Health: The Role of Bioavailability.

Polyphenols are a group of phytochemicals with potential health-promoting effects. They are classified as flavonoid (flavonols, flavanols, flavones, flavanones, isoflavones, and anthocyanins) and non-flavonoid molecules (phenolic acids, hydroxycinnamic acids, lignans, stilbenes, and tannins). Although an increasing number of trials have shown a correlation among polyphenol consumption and a reduction in risk factors for chronic diseases, discrepancies in explaining their positive effects have been found in terms of the bioavailability. In fact, polyphenols show a low bioavailability due to several factors: interaction with the food matrix, the metabolic processes mediated by the liver (phase I and II metabolism), intestine and microbiota. On the other hand, the biological activities of phenol compounds may be mediated by their metabolites, which are produced in vivo, and recent studies have confirmed that these molecules may have antioxidant and anti-phlogistic properties. This review discusses the studies performed in vivo, which consider the polyphenol bioavailability and their different food sources. Factors influencing the biological effects of the main classes of polyphenols are also considered.

Pigmented Corn Varieties as Functional Ingredients for Gluten-Free Products.

Oxidative stress, one among the several factors responsible for the gluten toxicity in celiac disease, together with inflammation and duodenal mucosal injury, are only partially reduced by the gluten-free diet. Thanks to their phenolic profile, the pigmented varieties of corn could be an interesting source of dietary antioxidants for the formulation of new gluten-free ingredients. The aim of this research was: (1) to characterize the phenolic profile and the associated antioxidant properties of corn samples with different pigmentation, using spectrophotometric and chromatographic techniques and (2) to assess the stability of anthocyanins during the gastro-intestinal digestion. The pigmented varieties showed a significantly higher content of polyphenols compared to the common yellow varieties and, as a consequence, a higher antioxidant activity. Although corn is among the cereals most frequently used in gluten-free products, it can produce an inflammatory response in some celiac patients. Therefore, after the chemical characterization, the safety of the pigmented varieties for celiac patients was confirmed using different in vitro models (cell agglutination test and the measure of transepithelial electrical resistance). Although in vivo studies are necessary, the data collected in this study underline that the pigmented corn could have a role in reducing the oxidative stress at the intestinal level in celiac subjects.