RESUMEN
PURPOSE: The objective of this study was to evaluate the capacity of modified phenols synthesized from hydroxytyrosol, a natural olive oil phenol, specifically those containing a selenium or sulphur group, to inhibit lipid peroxidation. METHODS: The compounds' abilities to inhibit lipid peroxidation in liver microsomes obtained from vitamin E-deficient rats were compared to hydroxytyrosol. RESULTS: All synthetic compounds had a significant higher ability to inhibit lipid peroxidation than hydroxytyrosol. Selenium derivates displayed a higher antioxidant activity than sulphur derivatives. In addition, the antioxidant activity increased with a higher number of heteroatoms in the hydroxytyrosol molecular structure. CONCLUSION: The study shows, for the first time, the ability of synthetic compounds, derived from the most active phenol present in olives in free form (hydroxytyrosol), and containing one or two atoms of sulphur or selenium, to inhibit the lipid peroxidation of vitamin E-deficient microsomes. The antioxidant activity of five thioureas, a disulfide, a thiol, three selenoureas, a diselenide, and a selenonium were evaluated and the results showed a higher inhibition of lipid peroxidation than the natural phenol. Selenium and sulphur derivatives of hydroxytyrosol are novel antioxidants with the potential to supplement the lack of vitamin E in the diet as natural alternatives for the prevention of diseases related to oxidative damage.
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Peroxidación de Lípido/efectos de los fármacos , Microsomas Hepáticos/efectos de los fármacos , Alcohol Feniletílico/análogos & derivados , Selenio/farmacología , Azufre/farmacología , Deficiencia de Vitamina E , Animales , Modelos Animales de Enfermedad , Alcohol Feniletílico/farmacología , RatasRESUMEN
PURPOSE: Low fruit and vegetable consumption is linked with an increased risk of death from vascular disease and cancer. The benefit of eating fruits and vegetables is attributed in part to antioxidants, vitamins and phytochemicals. Whether increasing intake impacts on markers of disease remains to be established. This study investigates whether increasing daily intake of fruits, vegetables and juices from low (approx. 3 portions), to high intakes (approx. 8 portions) impacts on nutritional and clinical biomarkers. Barriers to achieving the recommended fruit and vegetable intakes are also investigated. METHOD: In a randomised clinical trial, the participants [19 men and 26 women (39-58 years)] with low reported fruit, juice and vegetable intake (<3 portions/day) were randomised to consume either their usual diet or a diet supplemented with an additional 480 g of fruit and vegetables and fruit juice (300 ml) daily for 12 weeks. Nutritional biomarkers (vitamin C, carotenoids, B vitamins), antioxidant capacity and genomic stability were measured pre-intervention, at 4-, 8- and 12 weeks throughout the intervention. Samples were also taken post-intervention after a 6-week washout period. Glucose, homocysteine, lipids, blood pressure, weight and arterial stiffness were also measured. Intake of fruit, fruit juice and vegetables was reassessed 12 months after conducting the study and a questionnaire was developed to identify barriers to healthy eating. RESULTS: Intake increased significantly in the intervention group compared to controls, achieving 8.4 portions/day after 12 weeks. Plasma vitamin C (35%), folate (15%) and certain carotenoids [α-carotene (50%) and ß-carotene (70%) and lutein/zeaxanthin (70%)] were significantly increased (P < 0.05) in the intervention group. There were no significant changes in antioxidant capacity, DNA damage and markers of vascular health. Barriers to achieving recommended intakes of fruits and vegetables measured 12 months after the intervention period were amount, inconvenience and cost. CONCLUSION: While increasing fruit, juice and vegetable consumption increases circulating level of beneficial nutrients in healthy subjects, a 12-week intervention was not associated with effects on antioxidant status or lymphocyte DNA damage. TRIAL REGISTRATION: This trial was registered at Controlled-Trials.com; registration ISRCTN71368072.
Asunto(s)
Antioxidantes/metabolismo , Biomarcadores/sangre , Dieta , Frutas , Estado Nutricional , Verduras , Adulto , Actitud , Carotenoides , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vitaminas/sangreRESUMEN
Flavan-3-ols and methylxanthines have potential beneficial effects on human health including reducing cardiovascular risk. We performed a randomized controlled crossover intervention trial to assess the acute effects of consumption of flavan-3-ol-enriched dark chocolate, compared with standard dark chocolate and white chocolate, on the human metabolome. We assessed the metabolome in urine and blood plasma samples collected before and at 2 and 6 h after consumption of chocolates in 42 healthy volunteers using a nontargeted metabolomics approach. Plasma samples were assessed and showed differentiation between time points with no further separation among the three chocolate treatments. Multivariate statistics applied to urine samples could readily separate the postprandial time points and distinguish between the treatments. Most of the markers responsible for the multivariate discrimination between the chocolates were of dietary origin. Interestingly, small but significant level changes were also observed for a subset of endogenous metabolites. 1H NMR revealed that flavan-3-ol-enriched dark chocolate and standard dark chocolate reduced urinary levels of creatinine, lactate, some amino acids, and related degradation products and increased the levels of pyruvate and 4-hydroxyphenylacetate, a phenolic compound of bacterial origin. This study demonstrates that an acute chocolate intervention can significantly affect human metabolism.
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Chocolate/análisis , Flavonoides/administración & dosificación , Metaboloma/fisiología , Fitoquímicos/administración & dosificación , Aminoácidos/sangre , Aminoácidos/orina , Creatinina/sangre , Creatinina/orina , Estudios Cruzados , Femenino , Flavonoides/sangre , Flavonoides/orina , Humanos , Ácido Láctico/sangre , Ácido Láctico/orina , Masculino , Metabolómica/métodos , Fenilacetatos/sangre , Fenilacetatos/orina , Fitoquímicos/sangre , Fitoquímicos/orina , Periodo Posprandial , Ácido Pirúvico/sangre , Ácido Pirúvico/orina , Factores SexualesRESUMEN
Dietary modification may affect inflammatory processes and protect against chronic disease. In the present study, we examined the relationship between dietary patterns, circulating carotenoid and tocopherol concentrations, and biomarkers of chronic low-grade systemic inflammation in a 10-year longitudinal study of Scottish postmenopausal women. Diet was assessed by FFQ during 1997-2000 (n 3237, mean age 54·8 (SD 2·2) years). Participants (n 2130, mean age 66·0 (SD 2·2) years) returned during 2007-11 for follow-up. Diet was assessed by FFQ (n 1682) and blood was collected for the analysis of serum high-sensitivity C-reactive protein (hs-CRP), IL-6, serum amyloid A, E-selectin, lipid profile and dietary biomarkers (carotenoids, tocopherols and retinol). Dietary pattern and dietary biomarker (serum carotenoid) components were generated by principal components analysis. A past 'prudent' dietary pattern predicted serum concentrations of hs-CRP and IL-6 (which decreased across the quintiles of the dietary pattern; P= 0·002 and P= 0·001, respectively; ANCOVA). Contemporary dietary patterns were also associated with inflammatory biomarkers. The concentrations of hs-CRP and IL-6 decreased across the quintiles of the 'prudent' dietary pattern (P= 0·030 and P= 0·006, respectively). hs-CRP concentration increased across the quintiles of a 'meat-dominated' dietary pattern (P= 0·001). Inflammatory biomarker concentrations decreased markedly across the quintiles of carotenoid component score (P< 0·001 for hs-CRP and IL-6, and P= 0·016 for E-selectin; ANCOVA). Prudent dietary pattern and carotenoid component scores were negatively associated with serum hs-CRP concentration (unstandardised ß for prudent component: -0·053, 95% CI -0·102, -0·003; carotenoid component: -0·183, 95% CI -0·233, -0·134) independent of study covariates. A prudent dietary pattern (which reflects a diet high in the intakes of fish, yogurt, pulses, rice, pasta and wine, in addition to fruit and vegetable consumption) and a serum carotenoid profile characteristic of a fruit and vegetable-rich diet are associated with lower concentrations of intermediary markers that are indicative of CVD risk reduction.
Asunto(s)
Enfermedades Cardiovasculares/epidemiología , Carotenoides/sangre , Dieta/efectos adversos , Promoción de la Salud , Política Nutricional , Cooperación del Paciente , Tocoferoles/sangre , Biomarcadores/sangre , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/etiología , Enfermedades Cardiovasculares/prevención & control , Carotenoides/deficiencia , Carotenoides/uso terapéutico , Estudios de Cohortes , Femenino , Humanos , Estudios Longitudinales , Persona de Mediana Edad , Estado Nutricional , Análisis de Componente Principal , Estudios Prospectivos , Riesgo , Escocia/epidemiología , Tocoferoles/uso terapéutico , Vasculitis/sangre , Vasculitis/epidemiología , Vasculitis/etiología , Vasculitis/prevención & control , Vitamina A/sangre , Vitamina A/uso terapéutico , Deficiencia de Vitamina A/fisiopatología , Deficiencia de Vitamina E/fisiopatologíaRESUMEN
While oxidative damage owing to reactive oxygen species (ROS) often increases with advancing age and is associated with many age-related diseases, its causative role in ageing is controversial. In particular, studies that have attempted to modulate ROS-induced damage, either upwards or downwards, using antioxidant or genetic approaches, generally do not show a predictable effect on lifespan. Here, we investigated whether dietary supplementation with either vitamin E (α-tocopherol) or vitamin C (ascorbic acid) affected oxidative damage and lifespan in short-tailed field voles, Microtus agrestis. We predicted that antioxidant supplementation would reduce ROS-induced oxidative damage and increase lifespan relative to unsupplemented controls. Antioxidant supplementation for nine months reduced hepatic lipid peroxidation, but DNA oxidative damage to hepatocytes and lymphocytes was unaffected. Surprisingly, antioxidant supplementation significantly shortened lifespan in voles maintained under both cold (7 ± 2°C) and warm (22 ± 2°C) conditions. These data further question the predictions of free-radical theory of ageing and critically, given our previous research in mice, indicate that similar levels of antioxidants can induce widely different interspecific effects on lifespan.
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Antioxidantes/administración & dosificación , Arvicolinae/fisiología , Ácido Ascórbico/administración & dosificación , Longevidad/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , alfa-Tocoferol/administración & dosificación , Animales , Metabolismo Basal/efectos de los fármacos , Frío , Suplementos Dietéticos , Femenino , Masculino , Especies Reactivas de Oxígeno/farmacologíaRESUMEN
There are concerns that weight-loss (WL) diets based on very low carbohydrate (LC) intake have a negative impact on antioxidant status and biomarkers of cardiovascular and metabolic health. Obese men (n 16) participated in a randomised, cross-over design diet trial, with food provided daily, at approximately 8.3 MJ/d (approximately 70 % of energy maintenance requirements). They were provided with two high-protein diets (30 % of energy), each for a 4-week period, involving a LC (4 % carbohydrate) and a moderate carbohydrate (MC, 35 % carbohydrate) content. Body weight was measured daily, and weekly blood samples were collected. On average, subjects lost 6.75 and 4.32 kg of weight on the LC and MC diets, respectively (P < 0.001, SED 0.350). Although the LC and MC diets were associated with a small reduction in plasma concentrations of retinol, vitamin E (α-tocopherol) and ß-cryptoxanthin (P < 0.005), these were still above the values indicative of deficiency. Interestingly, plasma vitamin C concentrations increased on consumption of the LC diet (P < 0.05). Plasma markers of insulin resistance (P < 0.001), lipaemia and inflammation (P < 0.05, TNF-α and IL-10) improved similarly on both diets. There was no change in other cardiovascular markers with WL. The present data suggest that a LC WL diet does not impair plasma indices of cardiometabolic health, at least within 4 weeks, in otherwise healthy obese subjects. In general, improvements in metabolic health associated with WL were similar between the LC and MC diets. Antioxidant supplements may be warranted if LC WL diets are consumed for a prolonged period.
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Antioxidantes/metabolismo , Dieta Baja en Carbohidratos , Dieta Reductora/métodos , Carbohidratos de la Dieta/administración & dosificación , Proteínas en la Dieta/administración & dosificación , Obesidad/dietoterapia , Pérdida de Peso/fisiología , Adulto , Anciano , Ácido Ascórbico/sangre , Biomarcadores/sangre , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/etiología , Enfermedades Cardiovasculares/prevención & control , Estudios Cruzados , Criptoxantinas , Endotelio Vascular/efectos de los fármacos , Ingestión de Energía , Humanos , Hiperlipidemias/sangre , Mediadores de Inflamación/sangre , Resistencia a la Insulina , Masculino , Enfermedades Metabólicas/sangre , Enfermedades Metabólicas/etiología , Enfermedades Metabólicas/prevención & control , Persona de Mediana Edad , Necesidades Nutricionales , Obesidad/sangre , Factores de Riesgo , Vitamina A/sangre , Xantófilas/sangre , alfa-Tocoferol/sangreRESUMEN
PURPOSE: Platelets play a key role in haemostasis and wound healing, contributing to formation of vascular plugs. They are also involved in formation of atherosclerosic plaques. Some traditional diets, like the Mediterranean diet, are associated with a lower risk of cardiovascular disease. Components in these diets may have anti-platelet functions contributing to their health benefits. METHODS: We studied the effects of alperujo extract, an olive oil production waste product containing the majority of polyphenols found in olive fruits, through measurement of effects on platelet aggregation and activation in isolated human platelets, and through identification of changes in the platelet proteome. RESULTS: Alperujo extract (40 mg/L) significantly decreased in vitro ADP- (p = 0.002) and TRAP- (p = 0.02) induced platelet activation as measured by the flow cytometry using the antibody for p-selectin (CD62p), but it did not affect the conformation of the fibrinogen receptor as measured by flow cytometry using the antibodies for anti-fibrinogen, CD42a and CD42b. Alperujo extract (100 mg/L) inhibited both collagen- and TRAP-induced platelet aggregation by 5% (p < 0.05), and a combination of hydroxytyrosol and 3,4-dihydroxyphenylglycol were, at least partly, responsible for this effect. Proteomic analysis identified nine proteins that were differentially regulated by the alperujo extract upon ADP-induced platelet aggregation. These proteins represent important mechanisms that may underlie the anti-platelet effects of this extract: regulation of platelet structure and aggregation, coagulation and apoptosis, and signalling by integrin αIIb/ß3. CONCLUSIONS: Alperujo extract may protect against platelet activation, platelet adhesion and possibly have anti-inflammatory properties.
Asunto(s)
Plaquetas/efectos de los fármacos , Fitoterapia , Extractos Vegetales/farmacología , Aceites de Plantas/farmacología , Polifenoles/farmacología , Proteómica/métodos , Anticuerpos , Coagulación Sanguínea/efectos de los fármacos , Colágeno/metabolismo , Femenino , Fibrinógeno/efectos de los fármacos , Humanos , Masculino , Metoxihidroxifenilglicol/análogos & derivados , Metoxihidroxifenilglicol/metabolismo , Aceite de Oliva , Selectina-P/efectos de los fármacos , Alcohol Feniletílico/análogos & derivados , Alcohol Feniletílico/metabolismo , Adhesividad Plaquetaria/efectos de los fármacos , Agregación Plaquetaria/efectos de los fármacos , Complejo GPIb-IX de Glicoproteína Plaquetaria/metabolismoRESUMEN
A simple, fast and reliable method to quantify, simultaneously, 3,4-dihydroxyphenylglycol (DHPG), hydroxytyrosol (HT) and tyrosol (Ty) extracted and purified successfully from olive oil by-product, called alperujo, in animal plasma and tissues samples has been developed using a high-performance liquid chromatographic (HPLC) method with UV-Vis detection. Extraction of compounds is based on solid-phase extraction for plasma and homogenisation with zirconia beads and centrifugation for tissues. Calibration curves were linear for all three phenols at a relatively low concentration range (0.05-50µg/mL). This method has acceptable accuracy (91-95% in plasma and 63-100% in tissues), precision (1.11-8.26% intra-day and 0.32-9.5% inter-day) and sensitivity for detecting low concentrations of these phenols in small plasma volumes and several animal tissues such as liver, heart, kidney, muscle, testes, white adipose tissue (WAT) and brain.
RESUMEN
Evidence from a wide range of sources suggests that individuals taking aspirin and related non-steroidal anti-inflammatory drugs have reduced risk of large bowel cancer. Work in animals supports cancer reduction with aspirin, but no long-term randomised clinical trials exist in human beings, and randomisation would be ethically unacceptable because vascular protection would have to be denied to a proportion of the participants. However, opportunistic trials of aspirin, designed to test vascular protection, provide some evidence of a reduction in cancer, but only after at least 10 years. We summarise evidence for the potential benefit of aspirin and natural salicylates in cancer prevention. Possible mechanisms of action and directions for further work are discussed, and implications for clinical practice are considered.
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Antiinflamatorios no Esteroideos/uso terapéutico , Aspirina/uso terapéutico , Medicina Basada en la Evidencia , Neoplasias/prevención & control , Animales , Antiinflamatorios no Esteroideos/farmacología , Apoptosis/efectos de los fármacos , Aspirina/farmacología , Neoplasias de la Mama/prevención & control , Estudios de Casos y Controles , Estudios de Cohortes , Neoplasias del Colon/prevención & control , Inhibidores de la Ciclooxigenasa/farmacología , Inhibidores de la Ciclooxigenasa/uso terapéutico , Reparación de la Incompatibilidad de ADN/efectos de los fármacos , Evaluación Preclínica de Medicamentos , Medicina Basada en la Evidencia/organización & administración , Femenino , Humanos , Pólipos Intestinales/prevención & control , Masculino , Neoplasias/epidemiología , Neoplasias/etiología , Prostaglandina-Endoperóxido Sintasas/efectos de los fármacos , Neoplasias de la Próstata/prevención & control , Ensayos Clínicos Controlados Aleatorios como Asunto , Conducta de Reducción del Riesgo , Factores de TiempoRESUMEN
Diets rich in flavonoids may reduce the risk of developing colorectal cancer. Flavonoids are widely distributed in foods of plant origin, though in the UK tea is the main dietary source. Our objective was to evaluate any independent associations of total dietary and non-tea intake of four flavonoid subclasses and the risk of developing colorectal cancer in a tea-drinking population with a high colorectal cancer incidence. A population-based case-control study (264 cases with histologically confirmed incident colorectal cancer and 408 controls) was carried out. Dietary data gathered by FFQ were used to calculate flavonoid intake. Adjusted OR and 95 % CI were estimated by logistic regression. No linear association between risk of developing colorectal cancer and total dietary flavonol, procyanidin, flavon-3-ol or flavanone intakes was found, but non-tea flavonol intake was inversely associated with colorectal cancer risk (OR 0.6; 95 % CI 0.4, 1.0). Stratification by site of cancer and assessment of individual flavonols showed a reduced risk of developing colon but not rectal cancer with increasing non-tea quercetin intake (OR 0.5; 95 % CI 0.3, 0.8; P(trend) < 0.01). We concluded that flavonols, specifically quercetin, obtained from non-tea components of the diet may be linked with reduced risk of developing colon cancer.
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Dieta , Flavonoides/farmacología , Anciano , Índice de Masa Corporal , Estudios de Casos y Controles , Catequina/metabolismo , Catequina/farmacología , Neoplasias del Colon/genética , Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/prevención & control , Conducta Alimentaria , Femenino , Flavonoides/administración & dosificación , Flavonoides/metabolismo , Flavonoles/metabolismo , Flavonoles/farmacología , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo Genético , Neoplasias del Recto/genética , Valores de Referencia , Factores de Riesgo , Escocia/epidemiología , Encuestas y Cuestionarios , TéRESUMEN
Trials in free-living populations involving increased consumption of fruit and vegetables are difficult to monitor. We evaluated biomarkers for assessing fruit and vegetable intake and compliance in a 2-year trial. Postmenopausal women were randomised to 300 g additional fruit and vegetables per d (n 66), placebo (n 70) or potassium citrate (n 140). They completed dietary checklists (3-monthly) and food diaries or FFQ (yearly). We measured whole-blood folate, plasma vitamin C and homocysteine (yearly), serum vitamin E and carotenoids (at 12 months) and urinary vitamin K metabolites (yearly). Plasma vitamin C was associated with fruit and vegetable intake at baseline (r +0.31; P < 0.01), remaining significant only for the non-fruit and vegetable group at 12 months (r +0.43; P < 0.01). For the fruit and vegetable group, vitamin C increased by 5.9 micromol/l (P = 0.07) but was not significantly associated with fruit and vegetable intake; vitamin E, beta-carotene and beta-cryptoxanthin were higher compared with the non-fruit and vegetable group (P < 0.05); and whole-blood folate and the urinary 5C-aglycone metabolite of vitamin K were associated with vegetable intake. For all participants plasma vitamin C increased with increasing fruit and vegetable intakes, reaching a plateau of 90-95 micromol/l at intakes>500 g/d, whereas whole-blood folate, beta-carotene and beta-cryptoxanthin continued to increase. Concentrations of vitamin C, folate and beta-cryptoxanthin were lower and the 7C-aglycone metabolite of vitamin K higher, in smokers compared with non-smokers. Suitable markers for monitoring fruit and vegetable compliance include beta-carotene and beta-cryptoxanthin. Plasma vitamin C and whole-blood folate may be suitable for monitoring intakes in populations but for monitoring compliance the former may be restricted to low intakes of fruit and vegetables and the latter to vegetable intake.
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Biomarcadores/sangre , Dieta , Conducta Alimentaria , Frutas , Verduras , Vitaminas/metabolismo , Anciano , Femenino , Humanos , Persona de Mediana Edad , Fenómenos Fisiológicos de la Nutrición , Vitaminas/sangreRESUMEN
Life-history theory assumes that animal life histories are a consequence of trade-offs between current activities and future reproductive performance or survival, because resource supply is limited. Empirical evidence for such trade-offs in the wild are common, yet investigations of the underlying mechanisms are rare. Life-history trade-offs may have both physiological and ecological mediated costs. One hypothesized physiological mechanism is that elevated energy metabolism may increase reactive oxygen species production, leading to somatic damage and thus compromising future survival. We investigated the impact of experimentally elevated energy expenditure on oxidative damage, protection and lifespan in short-tailed field voles (Microtus agrestis) maintained in captivity to remove any confounding ecological factor effects. Energy expenditure was elevated via lifelong cold exposure (7+/-2 degrees C), relative to siblings in the warm (22+/-2 degrees C). No treatment effect on cumulative mortality risk was observed, with negligible effects on oxidative stress and antioxidant protection. These data suggest that in captive animals physiologically mediated costs on life history do not result from increased energy expenditure and consequent elevations in oxidative stress and reduced survival.
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Arvicolinae/metabolismo , Metabolismo Energético , Longevidad , Estrés Oxidativo , Animales , FríoRESUMEN
The effects of dietary antioxidant supplementation on oxidative stress and life span are confused. We maintained C57BL/6 mice at 7 +/- 2 degrees C and supplemented their diet with alpha-tocopherol from 4 months of age. Supplementation significantly increased (p = 0.042) median life span by 15% (785 days, n = 44) relative to unsupplemented controls (682 days, n = 43) and also increased maximum life span (oldest 10%, p = 0.028). No sex or sex by treatment interaction effects were observed on life span, with treatment having no effect on resting or daily metabolic rate. Lymphocyte and hepatocyte oxidative DNA damage and hepatic lipid peroxidation were unaffected by supplementation, but hepatic oxidative DNA damage increased with age. Using a cDNA macroarray, genes associated with xenobiotic metabolism were significantly upregulated in the livers of female mice at 6 months of age (2 months supplementation). At 22 months of age (18 months supplementation) this response had largely abated, but various genes linked to the p21 signaling pathway were upregulated at this time. We suggest that alpha-tocopherol may initially be metabolized as a xenobiotic, potentially explaining why previous studies observe a life span extension generally when lifelong supplementation is initiated early in life. The absence of any significant effect on oxidative damage suggests that the life span extension observed was not mediated via any antioxidant properties of alpha-tocopherol. We propose that the life span extension observed following alpha-tocopherol supplementation may be mediated via upregulation of cytochrome p450 genes after 2 months of supplementation and/or upregulation of p21 signaling genes after 18 months of supplementation. However, these signaling pathways now require further investigation to establish their exact role in life span extension following alpha-tocopherol supplementation.
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Frío , Longevidad/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , alfa-Tocoferol/farmacología , Animales , Suplementos Dietéticos , Femenino , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Hígado/química , Hígado/efectos de los fármacos , Hígado/metabolismo , Longevidad/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Análisis de Secuencia por Matrices de Oligonucleótidos , Sustancias Reactivas al Ácido Tiobarbitúrico/análisis , Factores de TiempoRESUMEN
Due to the success of therapeutic anti-inflammatory compounds to inhibit, retard, and reverse the development of colon cancer, the identification of dietary compounds as chemopreventives is being vigorously pursued. However, an important factor often overlooked is the metabolic transformation of the food-derived compounds in the gut that may affect their bioactivity. Commonly consumed dietary phenolics (esterified ferulic acid and its 5-5'-linked dimer), which have the potential to undergo predominant microbial transformations (de-esterification, hydrogenation, demethylation, dehydroxylation, and dimer cleavage), were incubated with human microbiota. The metabolites were identified (high-performance liquid chromatography and nuclear magnetic resonance) and confirmed to be present in fresh fecal samples from 4 human volunteers. The potential anti-inflammatory properties were compared by measuring the ability of the parent compounds and their metabolites to modulate prostanoid production in a cell line in which the inflammatory pathways were stimulated following a cytokine-induced insult. The compounds were readily de-esterified and hydrogenated, but no dimer cleavage occurred. Only the monomer underwent demethylation and selective de-hydroxylation. The resultant metabolites had differing effects on prostanoid production ranging from a slight increase to a significant reduction in magnitude. This suggests that the microbial transformation of dietary compounds will have important inflammatory implications in the chemoprevention of colon cancer.
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Antiinflamatorios no Esteroideos/metabolismo , Bacterias/metabolismo , Colon/microbiología , Ácidos Cumáricos/metabolismo , Antiinflamatorios no Esteroideos/química , Cromatografía Líquida de Alta Presión , Ácidos Cumáricos/química , Heces/microbiología , Humanos , Espectroscopía de Resonancia Magnética , Prostaglandinas/metabolismo , Factores de TiempoRESUMEN
Elevated levels of phospholipases, prostaglandin synthases and lipoxygenases in colonic cells at various stages of malignancy indicate a strong link between dietary lipids and colon cancer. Lipoxygenase-catalysed arachidonic acid metabolism plays a key role in colorectal carcinogenesis and has the potential to be modulated by phenolic compounds. Plant-based foods are rich sources of phenolic compounds and in the human colon they are predominantly available as simple phenolics such as the benzoic acids. Benzoic acids were determined in faecal waters from four volunteers consuming a western-style diet. Structure-activity relationships were established for the lipoxygenase-catalysed oxygenation of arachidonic acid using an oxygen electrode. All compounds studied inhibited this reaction (21-73%; p<0.001) and many of the structural features could be rationalised by computational modelling. No correlation was observed with the ability to act as reductants, supporting the hypothesis that their mode of inhibition may not be by a direct redox effect on the non-haem iron.
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Araquidonato 15-Lipooxigenasa/metabolismo , Ácido Araquidónico/metabolismo , Benzoatos/química , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Inhibidores de la Lipooxigenasa , Oxígeno/metabolismo , Ácido Araquidónico/química , Catálisis , Colon/efectos de los fármacos , Colon/metabolismo , Inhibidores Enzimáticos/química , Humanos , Oxidación-Reducción , Relación Estructura-ActividadRESUMEN
Many of the inflammatory pathways regulating the production of prostanoids are implicated in the development of colon cancer. Diets rich in fruits and vegetables are associated with decreased rates of colon cancer and this may reflect anti-inflammatory properties of some phytochemicals in plant-based foods. In order to ascertain which of the many dietary compounds may be protective, a cell-based screening method was established to determine their effects on the production of prostanoids. By up-regulating prostaglandin H synthase-2 in human colonic fibroblast cells with cytokines, we have investigated the potential protective effect of a structurally related group of phytochemicals on prostanoid biogenesis. Several of the compounds significantly inhibited prostanoid biogenesis, by up to 81% and others enhanced prostanoid production. All of the compounds that enhanced prostanoid production belonged to the hydroxylated benzoic acid family and good correlation was observed with their redox activity and the ability to enhance prostanoid production. Common structural features of the inhibitors were the presence of 4-hydroxyl and 3-methoxyl substituents on the aromatic ring and/or the presence of a three-carbon side-chain on C1.
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Colon/citología , Colon/efectos de los fármacos , Citocinas/farmacología , Fibroblastos/efectos de los fármacos , Estructuras de las Plantas/metabolismo , Prostaglandinas/biosíntesis , Células Cultivadas , Ciclooxigenasa 2/metabolismo , Inhibidores de la Ciclooxigenasa 2/química , Relación Dosis-Respuesta a Droga , Humanos , Estructuras de las Plantas/química , Regulación hacia Arriba/genéticaRESUMEN
The fate of anthocyanins and ellagitannins in rats was monitored following ingestion of raspberry juice. After 1 h low nM concentrations of unmetabolised anthocyanins were present in plasma but these declined by 2 h and after 4 h they were no longer detectable. For the first 2 h there was an almost full recovery of anthocyanins as they passed from the stomach through the duodenum/jejunum and into the ileum. After 3 h less than 50% were recovered, and the levels declined rapidly thereafter. Excretion of raspberry anthocyanins in urine over a 24 h period was equivalent to 1.2% of the amount ingested. Trace quantities of anthocyanins were detected in the caecum, colon and faeces and they were absent in extracts of liver, kidneys and brain. Urine also contained a number of phenolic acids but most were present in quantities well in excess of the 918 nmol of anthocyanins present in the ingested juice. These findings indicate that raspberry anthocyanins per se are poorly absorbed, probably prior to reaching the ileum, and that substantial amounts pass from the small to the large intestine where they are degraded by colonic bacteria. Ellagitannins disappeared in the stomach without accumulation of ellagic acid.
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Antocianinas/farmacocinética , Frutas/química , Taninos Hidrolizables/farmacocinética , Rosaceae/química , Animales , Antocianinas/sangre , Antocianinas/orina , Bebidas , Disponibilidad Biológica , Líquidos Corporales/química , Cromatografía de Gases y Espectrometría de Masas , Tracto Gastrointestinal/metabolismo , Cinética , Masculino , Ratas , Ratas Sprague-Dawley , Distribución TisularRESUMEN
Epidemiological studies assessing the health benefits of drinking black tea are equivocal. Such disparity may reflect an inability of semiquantitative assessment to consider how infusion time and addition of milk affect the bioavailability of potentially beneficial antioxidant polyphenols. Six brands of tea demonstrated similar increases in antioxidant capacity and total phenolic and catechin contents with increasing infusion time. These results were unaffected by the addition of milk. Consumption of black tea (400 mL) was associated with significant increases in plasma antioxidant capacity (10%) and concentrations of total phenols (20%), catechins (32%), and the flavonols quercetin (39%) and kaempferol (45%) (all p < 0.01) within 80 min. This was unaffected by adding milk. Infusion time may therefore be a more important determinant in the absorption of polyphenols from black tea. Observational studies assessing the health benefits of tea consumption require recording of brewing methods as well as frequency of consumption.
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Flavonoides/química , Fenoles/química , Té , Absorción , Animales , Bebidas , Biflavonoides/química , Catequina/análogos & derivados , Catequina/química , Humanos , Absorción Intestinal , Cinética , Leche , Polifenoles , Quercetina/químicaRESUMEN
The polyacetylene falcarinol, isolated from carrots, has been shown to be protective against chemically induced colon cancer development in rats, but the mechanisms are not fully understood. In this study CaCo-2 cells were exposed to falcarinol (0.5-100 microM) and the effects on proliferation, DNA damage, and apoptosis investigated. Low-dose falcarinol exposure (0.5-10 microM) decreased expression of the apoptosis indicator caspase-3 concomitantly with decreased basal DNA strand breakage. Cell proliferation was increased (1-10 microM), whereas cellular attachment was unaffected by <10 microM falcarinol. At concentrations above 20 microM falcarinol, proliferation of CaCo-2 cells decreased and the number of cells expressing active caspase-3 increased simultaneously with increased cell detachment. Furthermore, DNA single-strand breakage was significantly increased at concentrations above 10 microM falcarinol. Thus, the effects of falcarinol on CaCo-2 cells appear to be biphasic, inducing pro-proliferative and apoptotic characteristics at low and high concentrations of falcarinol, respectively.
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Apoptosis/efectos de los fármacos , División Celular/efectos de los fármacos , Daño del ADN/efectos de los fármacos , Diinos/farmacología , Alcoholes Grasos/farmacología , Células CACO-2 , Caspasa 3/metabolismo , Adhesión Celular/efectos de los fármacos , Daucus carota/química , Humanos , Extractos VegetalesRESUMEN
In a large cohort of older women, a mechanism-driven statistical technique for assessing dietary patterns that considers a potential nutrient pathway found two dietary patterns associated with lumbar spine and femoral neck bone mineral density. A "healthy" dietary pattern was observed to be beneficial for bone mineral density. INTRODUCTION: Dietary patterns represent a broader, more realistic representation of how foods are consumed, compared to individual food or nutrient analyses. Partial least-squares (PLS) is a data-reduction technique for identifying dietary patterns that maximizes correlation between foods and nutrients hypothesized to be on the path to disease, is more hypothesis-driven than previous methods, and has not been applied to the study of dietary patterns in relation to bone health. METHODS: Women from the Aberdeen Prospective Osteoporosis Screening Study (2007-2011, n = 2129, age = 66 years (2.2)) provided dietary intake using a food frequency questionnaire; 37 food groups were created. We applied PLS to the 37 food groups and 9 chosen response variables (calcium, potassium, vitamin C, vitamin D, protein, alcohol, magnesium, phosphorus, zinc) to identify dietary patterns associated with bone mineral density (BMD) cross-sectionally. Multivariable regression was used to assess the relationship between the retained dietary patterns and BMD at the lumbar spine and femoral neck, adjusting for age, body mass index, physical activity level, smoking, and national deprivation category. RESULTS: Five dietary patterns were identified, explaining 25% of the variation in food groups and 77% in the response variables. Two dietary patterns were positively associated with lumbar spine (per unit increase in factor 2: 0.012 g/cm2 [95% CI: 0.006, 0.01]; factor 4: 0.007 g/cm2 [95% CI: 0.00001, 0.01]) and femoral neck (factor 2: 0.006 g/cm2 [95% CI: 0.002, 0.01]; factor 4: 0.008 g/cm2 [95% CI: 0.003, 0.01)]) BMD. Dietary pattern 2 was characterized by high intakes of milk, vegetables, fruit and vegetable juices, and wine, and low intakes of processed meats, cheese, biscuits, cakes, puddings, confectionary, sweetened fizzy drinks and spirits while dietary pattern 4 was characterized by high intakes of fruits, red and white meats, and wine, and low intakes of vegetables and sweet spreads. CONCLUSION: Our findings using a robust statistical technique provided important support to initiatives focusing on what constitutes a healthy diet and its implications.