Colonic Coffee Phenols Metabolites, Dihydrocaffeic, Dihydroferulic, and Hydroxyhippuric Acids Protect Hepatic Cells from TNF-α-Induced Inflammation and Oxidative Stress.

Coffee presents beneficial health properties, including antiobesity effects. However, its effects on inflammation are controversial. Hydroxycinnamic acids are the main coffee phenolic bioactive compounds. In human bioavailability studies carried out with coffee, among the most abundant compounds found in urine and plasma were the colonic metabolites, dihydrocaffeic (DHCA), dihydroferulic (DHFA), and hydroxyhippuric (HHA) acids. To understand the hepato-protective potential of these three compounds, we tested whether treatment with realistic concentrations (0.5-10 µM) were effective to counteract inflammatory process and oxidative status induced by tumor necrosis factor α (TNF-α). First, we established a novel model of inflammation/oxidation using TNF-α and HepG2 cells. Afterwards, we evaluated the activity of DHCA, DHFA, and HHA against the inflammatory/oxidative challenge through the determination of the inflammatory mediators, interleukins (IL)-6, and IL-8 and chemokines, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1, as well as the levels of biomarkers of oxidative stress, such as reactive oxygen species, reduced glutathione, and the antioxidant enzymes glutathione peroxidase and reductase. Results showed that all three compounds have a potential hepato-protective effect against the induced inflammatory/oxidative insult.

Effect of Olive Pomace Oil on Cardiovascular Health and Associated Pathologies.

BACKGROUND: olive pomace oil (OPO) is a nutritionally relevant fat due to its high oleic acid content (C18:1) and the presence of a wide range of minor bioactive components. Although numerous in vitro and preclinical studies have been developed to study some of its characteristic components, the health effect of prolonged OPO consumption is unknown. METHODS: a randomised, blinded, cross-over, controlled clinical trial was carried out in 31 normocholesterolemic and 37 hypercholesterolemic subjects. Participants consumed 45 g/day of OPO or sunflower oil (SO) for 4 weeks, each preceded by a 3-week run-in/wash-out phase with corn oil (CO). RESULTS: regular consumption of OPO and SO had no statistically significant effect on any of the markers related to lipid profile, blood pressure, and endothelial function in both groups, except for eNOS levels, which were close to statistical significance due to the effect of oil (OPO and SO) (p = 0.083). A decrease in visceral fat (p = 0.028) in both groups was observed after OPO intake, accompanied by an increment of leptin (p = 0.017) in the hypercholesterolemic group. CONCLUSION: reducing visceral fat after prolonged OPO intake might contribute to improve cardiometabolic status, with a potentially positive effect on the vascular tone. Further clinical trials are needed to confirm the present results.

Olive Pomace Oil versus High Oleic Sunflower Oil and Sunflower Oil: A Comparative Study in Healthy and Cardiovascular Risk Humans.

Olive pomace oil (OPO) is mainly a source of monounsaturated fat together with a wide variety of bioactive compounds, such as triterpenic acids and dialcohols, squalene, tocopherols, sterols and aliphatic fatty alcohols. To date, two long-term intervention studies have evaluated OPO's health effects in comparison with high oleic sunflower oil (HOSO, study-1) and sunflower oil (SO, study-2) in healthy and cardiovascular risk subjects. The present study integrates the health effects observed with the three oils. Two randomized, blinded, cross-over controlled clinical trials were carried out in 65 normocholesterolemic and 67 moderately hypercholesterolemic subjects. Each study lasted fourteen weeks, with two four-week intervention phases (OPO versus HOSO or SO), each preceded by a three-week run-in or washout period. Regular OPO consumption reduced total cholesterol (p = 0.017) and LDL cholesterol (p = 0.018) levels as well as waist circumference (p = 0.026), and only within the healthy group did malondialdehyde (p = 0.004) levels decrease after OPO intake versus HOSO. Contrarily, after the SO intervention, apolipoprotein (Apo) B (p < 0.001) and Apo B/Apo A ratio (p < 0.001) increased, and to a lower extent Apo B increased with OPO. There were no differences between the study groups. OPO intake may improve cardiometabolic risk, particularly through reducing cholesterol-related parameters and waist circumference in healthy and hypercholesterolemic subjects.

Sustained Consumption of a Decaffeinated Green Coffee Nutraceutical Has Limited Effects on Phenolic Metabolism and Bioavailability in Overweight/Obese Subjects.

Knowledge on the bioavailability of coffee (poly)phenols mostly come from single dose postprandial studies. This study aimed at investigating the effects of regularly consuming a green coffee phenolic extract (GCPE) on the bioavailability and metabolism of (poly)phenols. Volunteers with overweight/obesity consumed a decaffeinated GCPE nutraceutical containing 300 mg hydroxycinnamates twice daily for two months. Plasma and urinary pharmacokinetics, and fecal excretion of phenolic metabolites were characterized by LC-MS-QToF at weeks 0 and 8. Fifty-four metabolites were identified in biological fluids. Regular consumption of the nutraceutical produced certain changes: reduced forms of caffeic, ferulic and coumaric acids in urine or 3-(3'-hydroxypenyl)propanoic, and 3,4-dihydroxybenzoic acids in feces significantly increased (p < 0.05) after 8 weeks; in contrast, coumaroylquinic and dihydrocoumaroylquinic acids in urine decreased (p < 0.05) compared to baseline excretion. The sum of intestinal and colonic metabolites increased after sustained consumption of GCPE, without reaching statistical significance, suggesting a small overall effect on (poly)phenols' bioavailability.

Regular Consumption of Green Coffee Phenol, Oat ß-Glucan and Green Coffee Phenol/Oat ß-Glucan Supplements Does Not Change Body Composition in Subjects with Overweight and Obesity.

Many in vitro and in vivo studies support that green coffee polyphenols (GCP) and beta-glucans (BG) present important hypolipidaemic and hypoglycaemic effects. However, their weight-management/-reducing properties are less clear. Considering that these compounds act on different metabolic pathways, their combination could increase their beneficial health effects. The aim of the present study was to investigate the effects of regularly consuming supplements containing GCP, BG or the novel GCP/BG combination on body composition in overweight/obese subjects without changing their dietary and physical activity habits, hence addressing the difficulty to adapt to lifestyle changes. A randomised, cross-over, blind trial was carried out in 29 volunteers who consumed GCP (300 mg), BG (2.5 g) or GCP/BG (300 mg + 2.5 g) twice a day for 8 weeks. At the beginning and end of each of the interventions, body weight, body mass index, body fat%, intracellular and extracellular water, skinfolds (tricipital, bicipital, subscapularis, suprailiac, leg and thigh) and body circumferences (waist, hip, thigh, calf, branchial) were measured. Along the study, volunteers filled out 72 h dietary records, and physical activity was measured using accelerometers. The results show that dietary intake and physical activity were unchanged throughout the study; however, there were no changes in any of the body composition parameters analysed with any of the food supplements. In conclusion, the regular intake of GCP, BG and GCP/BG, without changes in diet and physical activity, is not an efficient strategy to lose weight or induce other positive changes in body composition, although results should be taken with caution as the study was underpowered.

Influence of 8-week daily consumption of a new product combining green coffee hydroxycinnamates and beta-glucans on polyphenol bioavailability in subjects with overweight and obesity.

Nutraceuticals based on plant extracts rich in polyphenols, as well as dietary fibres, are new means to fight overweight/obesity and associated diseases. However, to understand the potential effects of polyphenols on health it is critical to study their bioavailability and metabolic fate. Consumption of a green coffee phenolic extract (GCPE) in combination with oat beta-glucan (BG) could affect the pharmacokinetic profile of the main polyphenols present in coffee (hydroxycinnamates). Moreover, the regular intake of the combination could also induce changes. Nine overweight men and women consumed a novel nutraceutical product containing 300 mg of green coffee hydroxycinnamic acids and 2.5 g of BG twice a day for 8 weeks. A pharmacokinetic study was carried out in blood and urine samples taken before (baseline) and at week 8 after the nutraceutical intervention, collecting samples at different times in a 0-24 h interval. Faecal samples were also obtained at 0 and 24 h after the intake of the nutraceutical at baseline and week 8. Phenolic metabolites were analysed by LC-MS-QToF. Results showed that polyphenols were differentially absorbed and extensively metabolized throughout the gastrointestinal tract. An apparent reduction in the excretion of small intestinal metabolites was accompanied by a tendency to increase colonic metabolites after sustained intake (p = 0.052). In conclusion, continued consumption of the GCPE/BG nutraceutical appears to enhance the absorption of hydroxycinnamates by increasing the colonic bioavailability of their derived metabolites compared to baseline, although the regular intake of the nutraceutical did not modify the metabolite profile in any of the biological samples.

Evaluation of novel nutraceuticals based on the combination of oat beta-glucans and a green coffee phenolic extract to combat obesity and its comorbidities. A randomized, dose-response, parallel trial.

Obesity and its associated comorbidities are a major public health concern worldwide. Reduced energy intake and increased physical activity interventions have limited success in the long term. Nutraceuticals might be an alternative means to help lose weight and reduce obesity-associated cardiometabolic risk factors without changes in the habitual diet. The objective of the present study was to comparatively evaluate the efficiency of nutraceuticals based on the combination of a decaffeinated green coffee bean extract (GCBE) and two types of oat beta-glucans (BG) with different physiochemical properties on obesity related biomarkers in overweight/obese subjects. A randomized, dose-response, parallel, blind study was carried out in four groups of subjects (n = 15 each) who consumed for 6 weeks, twice a day, a nutraceutical containing 3 g d-1 or 5 g d-1 doses of 35% or 70% BG and a fixed amount of GCBE providing 600 mg d-1 of phenols. 35% BG showed a 10 and 100 times higher molecular weight and viscosity, respectively, compared to 70% BG. Food intake, anthropometry and different cardiometabolic markers were assessed at the beginning and end of the intervention. According to the general model of variance with repeated measure analysis, the intervention caused positive changes in the levels of total cholesterol, LDL cholesterol, VLDL cholesterol, triglycerides, alanine aminotransferase, aspartate aminotransferase, haemoglobin A1c, insulin, systolic blood pressure (SBP), total body fat percentage (TBF%), visceral fat percentage, and waist and hip circumferences without differences among the treatments, except for SBP and TBF%. Looking into the rates of change [(end value - beginning value)/beginning value] of these parameters, 5 g - 70% BG was the treatment that lowered TBF% the most. In conclusion, 5 g - 70% BG may be more effective in helping to lose weight and additionally, it produced the least bloating according to participants' subjective perception.

Appetite and Satiety Effects of the Acute and Regular Consumption of Green Coffee Phenols and Green Coffee Phenol/Oat ß-Glucan Nutraceuticals in Subjects with Overweight and Obesity.

Green coffee has weight management properties, yet its effects on appetite and satiety remain unclear as few, mainly acute, studies perform objective measurements. Therefore, the influence on appetite/satiety of acute and regular consumption of two nutraceuticals, a decaffeinated green coffee phenolic extract (GC) alone or combined with oat ß-glucans (GC/BG), with known satiating properties, has been analysed subjectively using visual analog scales (VAS) and objectively measuring actual food intake and postprandial appetite and satiety hormones. A randomised, cross-over, blind trial was carried out in 29 overweight volunteers who consumed GC or GC/BG twice a day for 8 weeks. After acute (day = 0) and regular consumption (day = 56) of the nutraceuticals, satiety was measured at 30, 60, 90, 150, and 210 min, as well as food intake at breakfast (30 min) and lunch (300 min). Additionally, in a subgroup of participants (n = 9), cholecystokinin, peptide-YY, glucagon-like-peptide-1, ghrelin and leptin concentrations were analysed in blood samples taken at the same time-points. According to VAS results, GC/BG reduced hunger more efficiently than GC. However, there were no statistically significant differences in food intake. Comparing the effects of the acute consumption of GC/BG and GC, leptin concentration at 150 min was higher after GC/BG intake vs. GC. Moreover, when comparing the effects of regularly consuming the two nutraceuticals, maximum ghrelin level decreased with GC/BG vs. GC. In conclusion, acute and regular effects of the nutraceuticals on appetite/satiety differed, and subjective and objective results partially agreed; GC/BG may reduce hunger more efficiently than GC.

[Effectiveness of hydroxycinamates and beta-glucans as dietary tools against obesity and its associated dysfunctions, and their application as nutraceuticals]. / Eficacia de los hidroxicinamatos y los beta-glucanos como herramientas dietéticas frente a la obesidad y sus disfunciones asociadas, y su aplicación como nutracéutico.

INTRODUCTION: Over the last few years the prevalence of overweight and obesity has increased, affecting in certain parts of the world more than half of the adult population. Obesity has been related to disorders such as type-2 diabetes, non-alcoholic fatty liver disease, and cardiovascular diseases, among others, which has made of obesity the second cause of preventable death, only behind smoking. Bearing this in mind, it is necessary to find new strategies to overcome overweight/obesity and its associated pathologies. In this context, nutraceuticals and dietary supplements have become interesting tools thanks to their composition, rich in bioactive compounds beneficial to health. Among bioactive compounds, this study will focus on ß-glucans, a type of soluble dietary fiber, and hydroxycinnamic acids, a group of phenols. Both types of compounds show complex and multifactorial effects, acting as hypolipemic, hypoglycemic, antioxidant, prebiotic and satiating agents. They act by modulating different metabolic pathways, affecting the absorption and metabolism of lipids and carbohydrates, reducing oxidative damage, promoting the proliferation of beneficial bacterial species, and reducing dietary intake. It may be concluded that both beta-glucans and hydroxycinnamates have potential as a nutritional tool for the management of obesity and its associated metabolic dysfunctions.

INTRODUCCIÓN: Durante los últimos años se ha incrementado la incidencia de casos de sobrepeso/obesidad entre la población, afectando en ciertas partes del mundo a más de la mitad de la población adulta. La obesidad lleva asociada comorbilidades como la diabetes de tipo 2, la esteatosis hepática no alcohólica y las enfermedades cardiovasculares entre otras muchas, que la han convertido en la segunda causa de muerte evitable en el mundo, solo por detrás del tabaquismo. Ante esta nueva realidad se hace necesaria la búsqueda de nuevas estrategias para combatir el sobrepeso/obesidad y sus patologías asociadas. Los nutracéuticos o suplementos dietéticos se han convertido en una herramienta dietética de sumo interés gracias a su composición de compuestos bioactivos beneficiosos para la salud. De entre estos compuestos bioactivos, este estudio abordará en profundidad dos de ellos: una fibra soluble, los ß-glucanos procedentes de la avena, y un tipo de compuesto fenólico, los hidroxicinamatos. Ambos tipos de compuestos presentan efectos complejos y multifactoriales al actuar como agentes hipolipemiantes, hipoglucemiantes, antioxidantes, prebióticos o saciantes. Ejercen su efecto modulando diferentes vías metabólicas que afectan tanto a la absorción como al metabolismo de los lípidos y los glúcidos, reduciendo el daño oxidativo, promoviendo la proliferación de especies bacterianas beneficiosas y reduciendo la ingesta dietética. Se puede concluir que tanto los beta-glucanos como los hidroxicinamatos presentan potencial como herramienta nutricional en el manejo de distintas disfunciones metabólicas asociadas a la obesidad.

Green/Roasted Coffee May Reduce Cardiovascular Risk in Hypercholesterolemic Subjects by Decreasing Body Weight, Abdominal Adiposity and Blood Pressure.

In previous studies, after regularly consuming a green/roasted coffee blend, body weight, body fat%, glucose, plasminogen activator inhibitor-1 (PAI-1), resistin, leptin, ghrelin, diastolic (DBP) and systolic blood pressure (SBP) significantly changed in healthy and hypercholesterolemic subjects. However, glucagon, total-cholesterol (T-C), triglycerides (TG), LDL-cholesterol (LDL-C) and Homeostasis Model Assessment index to estimate insulin resistance (HOMA-IR) only changed in the hypercholesterolemics. This work looks into the antiobesity effects of coffee blend and into the relationship of antiobesity with the aforementioned cardiometabolic modifications in hypercholesterolemics. (1) Methods: Tricipital and subscapular skinfolds, hip, thigh, arm and waist circumference (WC) were measured in normocholesterolemic and hypercholesterolemics. To understand the relationship between cardiometabolic and antiobesity results in hypercholesterolemics, factor analysis was carried out using baseline values of the variables that changed. (2) Results: WC, WC/hip and WC/height showed significant coffee×group interaction, and in hypercholesterolemics tended to decrease. After factor analysis, three factors emerged, accounting for 29.46, 13.13 and 11.79% of variance. Only factor 1 (main loadings: WC, DBP and SBP, body weight, WC/hip and WC/height ratios, TG and ghrelin, inversely) decreased after coffee intake. (3) Conclusion: Regularly consuming green/roasted coffee may help to control body weight, and in hypercholesterolemics, may reduce cardiovascular risk by reducing abdominal adiposity and blood pressure.

Flavanol Bioavailability in Two Cocoa Products with Different Phenolic Content. A Comparative Study in Humans.

Cocoa has beneficial health effects partly due to its high flavanol content. This study was aimed at assessing the absorption and metabolism of polyphenols in two soluble cocoa products: a conventional (CC) and a flavanol-rich product (CC-PP). A crossover, randomized, blind study was performed in 13 healthy men and women. On two different days, after an overnight fast, volunteers consumed one serving of CC (15 g) or CC-PP (25 g) in 200 mL of semi-skimmed milk containing 19.80 mg and 68.25 mg of flavanols, respectively. Blood and urine samples were taken, before and after CC and CC-PP consumption, and analyzed by high-performance liquid chromatography coupled to electrospray ionisation and quadrupole time-of-flight mass spectrometry (HPLC-ESI-QToF-MS). Up to 10 and 30 metabolites were identified in plasma and urine, respectively. Phase II derivatives of epicatechin were identified with kinetics compatible with small intestine absorption, although the most abundant groups of metabolites were phase II derivatives of phenyl-γ-valerolactone and phenylvaleric acid, formed at colonic level. 5-(4'-Hydroxyphenyl)-γ-valerolactone-sulfate could be a sensitive biomarker of cocoa flavanol intake. CC and CC-PP flavanols showed a dose-dependent absorption with a recovery of 35%. In conclusion, cocoa flavanols are moderately bioavailable and extensively metabolized, mainly by the colonic microbiota.

TNF-α-induced oxidative stress and endothelial dysfunction in EA.hy926 cells is prevented by mate and green coffee extracts, 5-caffeoylquinic acid and its microbial metabolite, dihydrocaffeic acid.

The main phenol in mate and coffee, 5-caffeoylquinic-acid (5-CQA), and its relevant microbial metabolites, dihydrocaffeic (DHCA) and dihydroferulic (DHFA) acids, have shown oxidative-stress protective effects in HepG2 cells. To evaluate possible endothelial-protective effects of the extracts and compounds, endothelial EA.hy926 cells were pre-treated with yerba mate (YME) and green coffee bean (GCBE) phenolic extracts, 5-CQA, DHCA and DHFA and afterwards stressed with tumour-necrosis-factor-alpha (TNF-α). Then oxidative-stress markers and endothelial-nitric-oxide-synthase levels were studied. TNF-α (10 ng/mL, 24 h) depleted reduced glutathione (GSH) and eNOS levels, increased reactive oxygen species (ROS) production, glutathione peroxidase (GPx) and reductase (GR) activities, and protein oxidation (carbonyl groups, CG) in EA.hy926 cells. Pre-treatment with YME, GCBE, 5-CQA, DHCA at certain physiological concentrations, lowered ROS production, recovered depleted GSH, reduced GR and GPx activities, and CG levels, and enhanced eNOS concentration.. YME, GCBE and 5-CQA show antioxidant effects in endothelial cells playing DHCA an important role in such protection; moreover, the extracts, 5-CQA, DHCA and DHFA increased eNOS levels.

Moderate consumption of a soluble green/roasted coffee rich in caffeoylquinic acids reduces cardiovascular risk markers: results from a randomized, cross-over, controlled trial in healthy and hypercholesterolemic subjects.

PURPOSE: Coffee is rich in bioactive compounds with health beneficial properties, with green coffee presenting higher phenol content than roasted. We evaluated the effects of regularly consuming realistic amounts of a green/roasted coffee blend on cardiovascular health-related biomarkers. METHODS: A randomized, cross-over, controlled study was carried out in 25 normocholesterolemic [total cholesterol (TC) < 200 mg/dL] and 27 hypercholesterolemic (TC 200-240 mg/dL) subjects. During 8 weeks, volunteers consumed 6 g/day of soluble green/roasted (35:65) coffee or a control beverage (water or an isotonic drink). Blood pressure, heart rate and body weight were monitored at the end of each intervention, and serum lipids [TC, HDL-C, LDL-C, VLDL-C, triglycerides and phospholipids], cytokines and chemokines (IL-1ß, IL-2, IL-4, IL-5, IL-6, IL-7, IL-10, IL-12, IL-13, IL-17, G-CSF, GM-CSF, MCP-1, MIP-1ß, TNF-α, INF-γ), adhesion molecules (ICAM-1, VCAM-1), and C-reactive protein were measured. Plasma antioxidant capacity (FRAP, ORAC and ABTS methods), and lipid (malondialdehyde, MDA) and protein (carbonyl groups, CG) oxidation were also determined. RESULTS: Attending to the general lineal model of variance for repeated measures, after the green/roasted coffee intervention significant reductions in TC, LDL-C, VLDL-C and triglycerides levels (p = 0.006, 0.001, 0.003 and 0.017, respectively), and a significant group effect were observed (0.001, < 0.001, 0.019 and 0.027, respectively). Only within the hypercholesterolemic group, attending to the Bonferroni test, the aforementioned lipid parameters were significantly lower after regular green/roasted coffee intake compared to baseline values. Moreover, after the coffee stage, plasma antioxidant capacity improved, according to the increase in ORAC and FRAP values (p < 0.001 and p < 0.001, respectively) and decrease of MDA (p = 0.015) and CG (p < 0.001) levels, without differences between groups. Systolic (p = 0.001) and diastolic (p < 0.001) blood pressure, heart rate (p = 0.035), and body weight (p = 0.017) were reduced in both normo- and hypercholesterolemic groups. CONCLUSION: Regular consumption of moderate amounts of a soluble green/roasted (35:65) coffee blend may contribute to improve cardiovascular health in moderately hypercholesterolemic people, as reducing serum lipids, blood pressure and body weight effects, as well as increasing plasma antioxidant capacity, have been observed. Moreover, positive influences on blood pressure, body weight, and plasma antioxidant capacity were obtained in the healthy group. Therefore, incorporation of green coffee beans into the coffee brew can be recommended as part of a dietary strategy to protect from cardiovascular disease.

Regularly consuming a green/roasted coffee blend reduces the risk of metabolic syndrome.

PURPOSE: Preventive health effects of coffee could have a widespread impact on public health. Green coffee has more phenols than roasted, and thus is healthier, although with less acceptable organoleptic properties. Therefore, the effects of regularly consuming a green/roasted coffee blend (35/65) on the main components of MetS in humans were evaluated. METHODS: A crossover, randomized, controlled study was performed in 25 normocholesterolaemic and 27 hypercholesterolaemic men and women aged 18-45 years with BMI 18-25 kg/m2. Three servings/day of the blend, providing 510.6 mg hydroxycinnamic acids and 121.2 mg caffeine/day, were consumed versus a control drink, during 8 weeks each. Polyphenol and methylxanthine-rich foods were restricted along the study. At the beginning (baseline) and end of the control and coffee interventions, blood samples were collected and glucose, HDL-cholesterol, triglycerides, insulin, leptin, plasminogen activator inhibitor-1 (PAI-1), resistin and visfatin were analysed; waist circumference, %body fat, and blood pressure were measured and dietary records and physical activity questionnaires completed. RESULTS: Systolic and diastolic blood pressure decreased (p = 0.001 and p < 0.001, respectively) in both groups as well as %body fat (p = 0.001) which may be related to the lower leptin (p = 0.001), PAI-1 (p < 0.001) and resistin (p = 0.034) levels in the two groups after coffee consumption. Glucose concentration (p = 0.030) and insulin resistance (p = 0.011; HOMA-IR) also decreased, as well as triglyceride levels (p = 0.017), so that the reduction was much greater in the hypercholesterolaemics (group effect, p = 0.027). CONCLUSION: Regular consumption of the green/roasted coffee blend may be recommended to healthy and hypercholesterolaemic subjects to prevent MetS, as it produces positive effects on blood pressure, glucose and triglyceride levels.

Hydroxytyrosol in functional hydroxytyrosol-enriched biscuits is highly bioavailable and decreases oxidised low density lipoprotein levels in humans.

Hydroxytyrosol (HT) and its derivatives in olive oil protect low-density lipoproteins (LDL) against oxidation. Biscuits could be a convenient alternative to broaden consumers' choice of HT-rich foods, although the biscuit matrix could affect HT bioavailability. We performed a crossover, randomized, double-blind study to evaluate HT bioavailability in HT-enriched biscuits (HT-B) versus non-enriched biscuits (C-B), and the effects on oxidative postprandial status. On two separate days, 13 subjects consumed 30 g of C-B or HT-B (5.25mg HT) after overnight-fasting. Blood and urine were collected at different intervals and analysed by LC-MS-QToF. After HT-B consumption, plasma metabolites peaked between 0.5 and 1h and were extensively excreted in urine. HT-sulphate and 3,4-dihydroxyphenylacetic acid (DOPAC)-sulphate were the main metabolites, followed by DOPAC and homovanillic acid (HVA). HT-glucuronide, DOPAC-glucuronide, HVA-glucuronide and HVA-sulphate were also detected. Postprandial oxidised-LDL concentrations decreased with HT-B. HT is a promising functional ingredient and, in biscuits, it is highly bioavailable and lowers postprandial oxidised-LDL levels.

Evaluation of the Bioavailability and Metabolism of Nitroderivatives of Hydroxytyrosol Using Caco-2 and HepG2 Human Cell Models.

Considering that nitrocatechols present putative effects against Parkinson's disease, the absorption and metabolism of nitroderivatives of hydroxytyrosol (HT) were assessed using human cell model systems. The test compounds nitrohydroxytyrosol (NO2HT), nitrohydroxytyrosyl acetate (NO2HT-A), and ethyl nitrohydroxytyrosyl ether (NO2HT-E) were efficiently transferred across human Caco-2 cell monolayers as an intestinal barrier model, NO2HT-A and NO2HT-E being better (p < 0.05) absorbed (absorption rate (AR) = 1.4 ± 0.1 and 1.5 ± 0.2, respectively) than their precursor, NO2HT (AR = 1.1 ± 0.1). A significant amount of the absorbed compounds remained unconjugated (81, 70, and 33% for NO2HT, NO2HT-A, and NO2HT-E, respectively) after incubation in Caco-2 cells, being available for hepatic metabolism. Nitrocatechols were extensively taken up and metabolized by human hepatoma HepG2 cells as a model of the human liver. Both studies revealed extensive hydrolysis of NO2HT-A into NO2HT, whereas NO2HT-E was not hydrolyzed. Glucuronide (75-55%), methylglucuronide (25-33%), and methyl derivatives (0-12%) were the main nitrocatechol metabolites detected after metabolism in Caco-2 and HepG2 cells. In conclusion, NO2HT, NO2HT-A, and NO2HT-E show high in vitro bioavailability and are extensively metabolized by hepatic cells.

Pharmacokinetics of caffeine and its metabolites in plasma and urine after consuming a soluble green/roasted coffee blend by healthy subjects.

Coffee is widely consumed worldwide; therefore, the methylxanthines contained in coffee, mainly caffeine (CF), are among the most abundant bioactive compounds in our diet. In the present work, the bioavailability and metabolism of methylxanthines in a commercial soluble green/roasted coffee blend was studied. After a 3-day restriction of methylxanthine-containing foods, fasting healthy subjects (12 men and women) consumed the coffee product containing 70.69mg CF and 0.119mg theobromine (TB). Plasma samples were taken before (t=0h) and after coffee consumption at different time points (0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, 9, 10 and 12h). Urine was collected at baseline (-2-0h) and at different intervals (0-2, 2-5, 5-8, 8-12 and 12-24h). Samples were analyzed by HPLC-DAD and LC-MS-QToF, and pharmacokinetic parameters were calculated. CF was the main methylxanthine found in plasma (Cmax=10.50µM, Tmax=1.2h). In addition, seven methylxanthines and methyluric acids were detected between 0.5 and 12h after coffee intake, paraxanthine (PX) being the major metabolite (Cmax=3.36µM), followed by 1-methyluric acid (1-MU; Cmax=1.44µM) and 1-methylxanthine (1-MX; Cmax=1.27µM), identified in plasma samples for the first time. In 24h urine, eleven methylxanthines and methyluric acids were detected, 1-MU being the major metabolite (Cmax=150.52µM, Tmax=12h) amounting to 67.7% of the total urinary metabolites. In conclusion, a rapid absorption, metabolization and excretion of caffeine and its derived methylxanthines and methyluric acids have been observed after consumption of a green/roasted coffee product.