378 research outputs found
Resveratrol and inflammatory bowel disease: the evidence so far
Despite the fact that inflammatory bowel disease (IBD) has still no recognised therapy, treatments which have proven at least mildly successful in improving IBD symptoms include anti-inflammatory drugs and monoclonal antibodies targeting pro-inflammatory cytokines. Resveratrol, a natural (poly)phenol found in grapes, red wine, grape juice and several species of berries, has been shown to prevent and ameliorate intestinal inflammation. Here, we discuss the role of resveratrol in the improvement of inflammatory disorders involving the intestinal mucosa. The present review covers three specific aspects of resveratrol in the framework of inflammation: (i) its content in food; (ii) its intestinal absorption and metabolism; and (iii) its anti-inflammatory effects in the intestinal mucosa in vitro and in the very few in vivo studies present to date. Actually, if several studies have shown that resveratrol may down-regulate mediators of intestinal immunity in rodent models, only two groups have performed intervention studies in human subjects using resveratrol as an agent to improve IBD conditions. The effects of resveratrol should be further investigated by conducting well-designed clinical trials, also taking into account different formulations for the delivery of the bioactive compound
Variations in caffeine and chlorogenic acid contents of coffees: what are we drinking?
The effect of roasting of coffee beans and the extraction of ground coffee with different volumes of hot pressurised water on the caffeine and the total caffeoylquinic acids (CQAs) content of the resultant beverages was investigated. While caffeine was stable higher roasting temperatures resulted in a loss of CQAs so that the caffeine/CQA ratio was a good marker of the degree of roasting. The caffeine and CQA content and volume was determined for 104 espresso coffees obtained from coffee shops in Scotland, Italy and Spain, limited numbers of cappuccino coffees from commercial outlets and several instant coffees. The caffeine content ranged from 48–317 mg per serving and CQAs from 6–188 mg. It is evident that the ingestion of 200 mg of caffeine per day can be readily and unwittingly exceeded by regular coffee drinkers. This is the upper limit of caffeine intake from all sources recommended by US and UK health agencies for pregnant women. In view of the variable volume of serving sizes, it is also clear that the term “one cup of coffee” is not a reproducible measurement for consumption, yet it is the prevailing unit used in epidemiology to assess coffee consumption and to link the potential effects of the beverage and its components on the outcome of diseases. More accurate measurement of the intake of coffee and its potentially bioactive components are required if epidemiological studies are to produce more reliable information
Bioavailability of black tea theaflavins: absorption, metabolism, and colonic catabolism
Data obtained with in vitro fecal incubations and a feeding study indicate black tea theaflavin and its galloyl derivatives are not absorbed in detectable amounts in either the upper or lower gastrointestinal tract. The theaflavin skeleton is comparatively resistant to degradation by colonic bacteria with a 67% recovery being obtained after a 24 h incubation, which yielded 21 phenolic and aromatic catabolites. The theaflavin galloyl moiety was removed by the microbiota, and the released gallic acid further transformed to 3-O- and 4-O-methyl gallic acids, pyrogallol-1-sulfate and pyrogallol-2-sulfate, which were excreted in urine in amounts equivalent to 94% of intake. The main urinary product potentially derived from breakdown of the theaflavin skeleton was 3-(4′-hydroxyphenyl)propionic acid. A number of the colonic catabolites originating from gallic acid and theaflavins has been reported to be bioactive in ex vivo and in vitro models with a variety of potential modes of action
Transthyretin binding heterogeneity and antiamyloidogenic activity of natural polyphenols and their metabolites
Transthyretin (TTR) is an amyloidogenic protein, the amyloidogenic
potential of which is enhanced by a number of specific
point mutations. The ability to inhibit TTR fibrillogenesis
is known for several classes of compounds, including natural
polyphenols, which protect the native state of TTR by specifically
interacting with its thyroxine binding sites. Comparative
analyses of the interaction and of the ability to protect the TTR
native state for polyphenols, both stilbenoids and flavonoids,
and some of their main metabolites have been carried out. A
main finding of this investigation was the highly preferential
binding of resveratrol and thyroxine, both characterized by negative
binding cooperativity, to distinct sites in TTR, consistent
with the data of x-ray analysis of TTR in complex with both
ligands. Although revealing the ability of the two thyroxine
binding sites of TTR to discriminate between different ligands,
this feature has allowed us to evaluate the interactions of polyphenols
with both resveratrol and thyroxine preferential binding
sites, by using resveratrol and radiolabeled T4 as probes.
Among flavonoids, genistein and apigenin were able to effectively
displace resveratrol from its preferential binding site,
whereas genistein also showed the ability to interact, albeit
weakly, with the preferential thyroxine binding site. Several
glucuronidated polyphenol metabolites did not exhibit significant
competition for resveratrol and thyroxine preferential
binding sites and lacked the ability to stabilize TTR. However,
resveratrol-3-O-sulfate was able to significantly protect the protein
native state. A rationale for the in vitro properties found for
polyphenol metabolites was provided by x-ray analysis of their
complexes with TTR
Colonic Metabolism of Polyphenols From Coffee, Green Tea, and Hazelnut Skins
Dietary polyphenolic compounds are poorly absorbed in
the small intestine. The absorbed fraction follows the common metabolic pathway of drugs, undergoing phase II enzymatic detoxification with the conjugation of glucuronic acid, sulfate, and methyl groups. However, the unabsorbed fraction can reach the colon, becoming available for the wide array of enzymes produced by the local commensal microbiota. Gut bacteria can hydrolyze glycosides, glucuronides, sulfates, amides, esters, and lactones and are able to break down the polyphenolic skeleton and perform
reactions of reduction, decarboxylation, demethylation, and
dehydroxylation. These complex modifications generate several low–molecular-weight metabolites that can be efficiently absorbed in situ, subsequently undergoing further phase II metabolism, locally and/or at the liver level, before entering the systemic blood circulation and finally being excreted in urine in substantial quantities that exceed the excretion of phenolic metabolites formed in the upper gastrointestinal tract. This brief work focuses on the phenolic composition and colonic microbial transformation of 2 of the most polyphenol-rich dietary sources, namely, green tea and
coffee, and a new interesting and innovative ingredient, hazelnut skin, recently evaluated as one of the richest edible sources of polyphenolic compounds
Quantification of Urinary Phenyl-γ-Valerolactones and Related Valeric Acids in Human Urine on Consumption of Apples
Flavan-3-ols are dietary bioactive molecules that have beneficial effects on human health and reduce the risk of various diseases. Monomeric flavan-3-ols are rapidly absorbed in the small intestine and released in the blood stream as phase II conjugates. Polymeric flavan-3-ols are extensively metabolized by colonic gut microbiota into phenyl-γ-valerolactones and their related phenylvaleric acids. These molecules are the main circulating metabolites in humans after the ingestion of flavan-3-ol rich-products; nevertheless, they have received less attention and their role is not understood yet. Here, we describe the quantification of 8 phenyl-γ-valerolactones and 3 phenylvaleric acids in the urine of 11 subjects on consumption of apples by using UHPLC-ESI-Triple Quad-MS with pure reference compounds. Phenyl-γ-valerolactones, mainly as sulfate and glucuronic acid conjugates, reached maximum excretion between 6 and 12 after apple consumption, with a decline thereafter. Significant differences were detected in the cumulative excretion rates within subjects and in the ratio of dihydroxyphenyl-γ-valerolactone sulfate to glucuronide conjugates. This work observed for the first time the presence of two distinct metabotypes with regards to the excretion of phenyl-γ-valerolactone phase II conjugates
Possible role of diet in cancer: systematic review and multiple meta-analyses of dietary patterns, lifestyle factors, and cancer risk
Context: Evidence of an association between dietary patterns derived a posteriori and risk of cancer has not been reviewed comprehensively. Objective: The aim of this review was to investigate the relation between a posteriori–derived dietary patterns, grouped as healthy or unhealthy, and cancer risk. The relation between cancer risk and background characteristics associated with adherence to dietary patterns was also examined. Data Sources: PubMed and Embase electronic databases were searched. Study Selection: A total of 93 studies including over 85 000 cases, 100 000 controls, and 2 000 000 exposed individuals were selected. Data Extraction: Data were extracted from each identified study using a standardized form by two independent authors. Results: The most convincing evidence (significant results from prospective cohort studies) supported an association between healthy dietary patterns and decreased risk of colon and breast cancer, especially in postmenopausal, hormone receptor–negative women, and an association between unhealthy dietary patterns and increased risk of colon cancer. Limited evidence of a relation between an unhealthy dietary pattern and risk of upper aerodigestive tract, pancreatic, ovarian, endometrial, and prostatic cancers relied only on case–control studies. Unhealthy dietary patterns were associated with higher body mass index and energy intake, while healthy patterns were associated with higher education, physical activity, and less smoking. Potential differences across geographical regions require further evaluation. Conclusions: The results suggest a potential role of diet in certain cancers, but the evidence is not conclusive and may be driven or mediated by lifestyle factors
Compositional study and antioxidant potential of Ipomoea hederacea Jacq. and Lepidium sativum L. seeds
The present investigation has been carried out to find the proximate composition, amino acids, metal contents, oil composition as well as the antioxidant capacity of the seeds of Ipomoea hederacea Jacq. and Lepidium sativum L. Proximate composition indicated a great difference in oil (14.09\ub10.66, 28.03\ub11.05) and fibre (16.55\ub10.31, 6.75\ub11.20) contents for I. hederacea and L. sativum, respectively. Fatty acid profile indicated that oleic acid (19.50 \ub1 0.37, 30.50 \ub1 0.16) and linoleic acid (52.09 \ub1 0.48, 8.60 \ub1 0.38) are major fatty acids. \u3b3-Tocopheol and alfa-tocopheol (28.70 \ub1 0.14, 111.56 \ub1 0.37) were the most abundant in the seed oil of I. hederacea and L. sativum, respectively. Results of antioxidant assays like TEAC, FRAP and TRAP indicated that L. sativum has much greater antioxidant potential than I. hederacea
Use of Dairy and Plant-Derived Lactobacilli as Starters for Cherry Juice Fermentation
BACKGROUND: Lactic acid bacteria (LAB) exhibit a great biodiversity that can be exploited for different purposes, such as to enhance flavours or metabolize phenolic compounds. In the present study, the use of dairy and plant-derived LAB strains to perform cherry juice fermentation is reported. METHODS: The growth ability of Lactobacillus plantarum, Lactobacillus casei, Lactobacillus paracasei and Lactobacillus rhamnosus was studied in cherry juice. Profiling of sugars, organic acids and volatile compounds was performed by GC-MS (Gas Chromatography-Mass Spectrometry), while the phenolic fraction was characterized using UHPLC (Ultra High Performance Liquid Chromatography) equipped with a linear ion trap-mass spectrometer. RESULTS: Sucrose significantly decreased in all fermented samples as well as malic acid, converted to lactic acid by malolactic fermentation. The total amount of volatile compounds increased. Specifically, propyl acetate, an ester with fruit notes, reached the highest concentration in L. rhamnosus and L. paracasei (dairy strains) fermented juices. Phenolics were extensively metabolized: caffeic acid was converted into dihydrocaffeic acid, p-coumaric acid into 4-ethylphenol and phenyllactic acid was produced. CONCLUSION: Lactic acid fermentation confer fruit notes to the juice and enhance phenyllactic acids, especially employing dairy strains (L. rhamnosus and L. paracasei). The level of dihydrocaffeic acid, a compound with putative biological activity was also increased (in particular with L. plantarum)
Total antioxidant capacity of the diet is inversely and independently related to plasma concentration of high-sensitivity C-reactive protein in adult Italian subjects
Inflammation, a risk factor for cardiovascular disease, is associated with low plasma levels of antioxidant vitamins. In addition to vitamins, other antioxidants modulate the synthesis of inflammatory markers in vitro and contribute to the total antioxidant capacity (TAC) of a diet. However, the relationship between dietary TAC and markers of inflammation has never been evaluated in vivo. We investigated the relationship between dietary TAC and markers of systemic (high-sensitivity C-reactive protein (hs-CRP), leucocytes) and vascular (soluble intercellular cell adhesion molecule-1) inflammation in 243 non-diabetic subjects. General Linear Model (GLM) analysis showed a significant (P=0·005) inverse relationship between hs-CRP and quartiles of energy-adjusted dietary TAC, even when recognized modulating factors of inflammation, namely alcohol, fibre, vitamin C, α-tocopherol, β-carotene, BMI, waist circumference, HDL-cholesterol, hypertension, insulin sensitivity and plasma β-carotene, were included in the model as covariates (P=0·004). The relationship was stronger for subjects with hypertension (P=0·013 v. P=0·109 for normotensive individuals). Among dietary factors, TAC was significantly higher (5·3 (sd 3·0) v. 4·9 (sd 2·7) mmol Trolox/d; P=0·026) in subjects with low plasma hs-CRP (range: 0·0–4·1 mg/l) than in subjects with high plasma hs-CRP (range: 4·2–27·8 mg/l). We conclude that dietary TAC is inversely and independently correlated with plasma concentrations of hs-CRP and this could be one of the mechanisms explaining the protective effects against CVD of antioxidant-rich foods such as fruits, whole cereals and red wine. This could be of particular significance for subjects with high blood pressure
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