RESUMO
Few studies have investigated the relationships between organic food consumption, dietary patterns, monetary diet cost, health, and the environment. To address these issues, a consortium of French epidemiologists, nutritionists, economists, and toxicologists launched the BioNutriNet project in 2013. In 2014, an FFQ documented the usual organic and nonorganic (conventional) food consumption of approximately 35,000 NutriNet-Santé participants. Then, individual organic and conventional food intakes were merged with price, environmental, and pesticide residue data sets, which distinguished between conventional and organic farming methods. Many studies were conducted to characterize organic consumers and their environmental impacts (i.e., greenhouse gas emissions, energy demand, and land use) and organic food consumption impacts on health. We observed that organic consumers had diets that were healthier and richer in plant-based food than nonorganic consumers. Their diets were associated with higher monetary costs, lower environmental impacts, and reduced exposure to certain pesticide residues. Regular consumption of organic food was associated with reduced risks of obesity, type 2 diabetes, postmenopausal breast cancer, and lymphoma. Although several observations have been confirmed by several studies conducted in other countries, our results should be replicated in other cultural settings and coupled with experimental studies to be able to draw causal conclusions. Finally, the main finding of the BioNutriNet project is that while organic food consumption could be associated with positive externalities on human health and the environment, organic-based diets should be accompanied by dietary shifts toward plant-based diets to allow for better planetary and human health.
Assuntos
Diabetes Mellitus Tipo 2 , Alimentos Orgânicos , Dieta/métodos , Meio Ambiente , Nível de Saúde , HumanosRESUMO
Tryptophan (Trp) is an essential amino-acid and the precursor of many biologically active substances such as kynurenine (KYN) and serotonin (5HT). Its metabolism is involved in different physiopathological states, such as cardiovascular diseases, cancer, immunomodulation or depression. Hence, the quantification of Trp catabolites, from both KYN and 5HT pathways, might be usefulfor the discovery of novel diagnostic and follow-up biomarkers. We have developed a simple method for quantification of Trp and 8 of its metabolites,involved in both KYN and 5HT pathways, using liquid chromatography coupled to tandem mass spectrometry. We also validated the methodin human plasma samples, according to NF EN ISO 15189 criteria. Our method shows acceptable intra- and inter-day coefficients of variation (CV) (<12% and <16% respectively). The linearity entirelycovers the human plasma range. Stabilities of whole blood and of residues weredetermined, as well as the use of 2 different types of collectiontube, enabling us to adapt our process. Matrix effects and reference values showed good agreement compared to the literature. We propose here a method allowing the simultaneous quantification of a panel of Trp catabolites, never used before to our knowledge. This method, witha quickchromatographic runtime (15min) and simple sample preparation, has beenvalidated according to NF EN ISO 15189 criteria. The method enables the detailed analysis of these metabolic pathways, which are thought to be involved in a number of pathological conditions.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Triptofano/sangue , Triptofano/metabolismo , Cromatografia Líquida de Alta Pressão/instrumentação , Cromatografia Líquida/métodos , Desenho de Equipamento , Humanos , Cinurenina/análogos & derivados , Cinurenina/sangue , Cinurenina/metabolismo , Limite de Detecção , Serotonina/análogos & derivados , Serotonina/sangue , Serotonina/metabolismo , Espectrometria de Massas em Tandem/instrumentação , Triptofano/análogos & derivadosRESUMO
BACKGROUND: Endogenous (heterophile, human anti-animal ) antibodies are a known cause of interference in immunoassays. CASE REPORT: A patient with hypercalcemia and low PTH levels was investigated. The serum 25OH vitamin D (25OHD) concentration was above the analytical range of the automated analyser (>150ng/mL) but serum dilutions were not linear. A myeloma-related monoclonal peak of immunoglobulin G (30g/L) was found. RESULTS: Alternative 25OHD assays (RIA, automated analysers, mass spectrometry) all found concentrations <25ng/mL. NabTM columns (Thermo Scientific) eliminated the endogenous immunoglobulin from the serum thus allowing the initial analyser to provide correct results. DISCUSSION AND CONCLUSION: The potentially misleading point was that the apparent very high 25OHD levels were concomitant with hypercalcemia and low PTH levels thus mimicking vitamin D intoxication. Identifying assay interferences requires clinical awareness but, when suspected, one should be aware that technical tools or alternate assays are available to correct some interferences, including monoclonal immunoglobulins.
Assuntos
Hipercalcemia/sangue , Vitamina D/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Hormônio Paratireóideo/sangueRESUMO
Crohn's disease (CD) and irritable bowel syndrome (IBS) involve brain-gut dysfunctions where vagus nerve is an important component. The aim of this work was to study the association between vagal tone and markers of stress and inflammation in patients with CD or IBS compared to healthy subjects (controls). The study was performed in 73 subjects (26 controls, 21 CD in remission and 26 IBS patients). The day prior to the experiment, salivary cortisol was measured at 8:00 AM and 10:00 PM. The day of the experiment, subjects completed questionnaires for anxiety (STAI) and depressive symptoms (CES-D). After 30 min of rest, ECG was recorded for heart rate variability (HRV) analysis. Plasma cortisol, epinephrine, norepinephrine, TNF-alpha and IL-6 were measured in blood samples taken at the end of ECG recording. Compared with controls, CD and IBS patients had higher scores of state-anxiety and depressive symptomatology. A subgroup classification based on HRV-normalized high frequency band (HFnu) as a marker of vagal tone, showed that control subjects with high vagal tone had significantly lower evening salivary cortisol levels than subjects with low vagal tone. Such an effect was not observed in CD and IBS patients. Moreover, an inverse association (r = â-0.48; p<0.05) was observed between the vagal tone and TNF-alpha level in CD patients exclusively. In contrast, in IBS patients, vagal tone was inversely correlated with plasma epinephrine (r = â-0.39; p<0.05). No relationship was observed between vagal tone and IL-6, norepinephrine or negative affects (anxiety and depressive symptomatology) in any group. In conclusion, these data argue for an imbalance between the hypothalamus-pituitary-adrenal axis and the vagal tone in CD and IBS patients. Furthermore, they highlight the specific homeostatic link between vagal tone and TNF-alpha in CD and epinephrine in IBS and argue for the relevance of vagus nerve reinforcement interventions in those diseases.
Assuntos
Doença de Crohn/fisiopatologia , Epinefrina/sangue , Hidrocortisona/metabolismo , Síndrome do Intestino Irritável/fisiopatologia , Fator de Necrose Tumoral alfa/sangue , Nervo Vago/fisiopatologia , Adolescente , Adulto , Estudos de Casos e Controles , Análise por Conglomerados , Doença de Crohn/sangue , Doença de Crohn/metabolismo , Feminino , Frequência Cardíaca , Humanos , Hidrocortisona/sangue , Interleucina-6/sangue , Síndrome do Intestino Irritável/sangue , Síndrome do Intestino Irritável/metabolismo , Masculino , Pessoa de Meia-Idade , Norepinefrina/sangue , Saliva/metabolismo , Adulto JovemRESUMO
Experimental studies suggest that carotenoids and retinol may play a role in carcinogenesis, but epidemiological evidence is lacking. We investigated the prospective associations between plasma concentrations of major carotenoids and retinol, and overall and breast cancer risk. A nested case-control study included all first incident cancer cases diagnosed in the SU.VI.MAX cohort between 1994 and 2002 (n = 159 cases, 1 matched control/case). Baseline plasma concentrations of carotenoids and retinol were measured by high-performance liquid chromatography. Conditional logistic regression was used to assess odds ratios for an increase of 0.1 µmol/L [odds ratio (OR)] and 95% confidence intervals (CI). Plasma ß-carotene (OR = 0.95, 95% CI = 0.90-0.99, Ptrend = 0.04) and ß-cryptoxanthin concentrations (OR = 0.89, 95% CI = 0.81-0.99, Ptrend = 0.03) were inversely associated with overall cancer risk. Plasma ß-cryptoxanthin concentration was inversely associated with breast cancer risk (OR = 0.83, 95% CI = 0.71-0.96, Ptrend = 0.02). The OR between plasma lycopene concentration and overall cancer risk was 1.07 (0.99-1.15), Ptrend = 0.06. This association turned significant (Ptrend = 0.01) when excluding cancer cases diagnosed during the first year of follow-up. This prospective study suggests an inverse association between plasma concentrations of ß-cryptoxanthin and both overall and breast cancer risk, and an inverse association between ß-carotene and overall cancer risk. The direct association between lycopene concentration and cancer risk deserves further investigation.
Assuntos
Neoplasias da Mama/sangue , Criptoxantinas/sangue , Vitamina A/sangue , beta Caroteno/sangue , Adulto , Índice de Massa Corporal , Carotenoides/sangue , Estudos de Casos e Controles , Cromatografia Líquida de Alta Pressão , Neoplasias Colorretais/sangue , Feminino , Seguimentos , Neoplasias de Cabeça e Pescoço/sangue , Humanos , Modelos Logísticos , Neoplasias Pulmonares/sangue , Licopeno , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Neoplasias da Próstata/sangue , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de RiscoRESUMO
Hyperhomocysteinemia, characterized by high plasma homocysteine levels, is recognized as an independent risk factor for cardiovascular diseases. The increased synthesis of homocysteine, a product of methionine metabolism involving B vitamins, and its slower intracellular utilization cause increased flux into the blood. Plasma homocysteine level is an important reflection of hepatic methionine metabolism and the rate of processes modified by B vitamins as well as different enzyme activity. Lowering homocysteine might offer therapeutic benefits. However, approximately 50% of hyperhomocysteinemic patients due to cystathionine-beta-synthase deficiency are biochemically responsive to pharmacological doses of B vitamins. Therefore, effective treatments to reduce homocysteine levels are needed, and gene therapy could provide a novel approach. We recently showed that hepatic expression of DYRK1A, a serine/threonine kinase, is negatively correlated with plasma homocysteine levels in cystathionine-beta-synthase deficient mice, a mouse model of hyperhomocysteinemia. Therefore, Dyrk1a is a good candidate for gene therapy to normalize homocysteine levels. We then used an adenoviral construct designed to restrict expression of DYRK1A to hepatocytes, and found decreased plasma homocysteine levels after hepatocyte-specific Dyrk1a gene transfer in hyperhomocysteinemic mice. The elevation of pyridoxal phosphate was consistent with the increase in cystathionine-beta-synthase activity. Commensurate with the decreased plasma homocysteine levels, targeted hepatic expression of DYRK1A resulted in elevated plasma paraoxonase-1 activity and apolipoprotein A-I levels, and rescued the Akt/GSK3 signaling pathways in aorta of mice, which can prevent homocysteine-induced endothelial dysfunction. These results demonstrate that hepatocyte-restricted Dyrk1a gene transfer can offer a useful therapeutic targets for the development of new selective homocysteine lowering therapy.
Assuntos
Aorta/metabolismo , Apolipoproteína A-I/sangue , Terapia Genética , Hepatócitos/metabolismo , Homocisteína , Proteínas Serina-Treonina Quinases/biossíntese , Proteínas Tirosina Quinases/biossíntese , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Aorta/patologia , Cistationina beta-Sintase/genética , Cistationina beta-Sintase/metabolismo , Homocisteína/sangue , Hiper-Homocisteinemia/sangue , Hiper-Homocisteinemia/genética , Hiper-Homocisteinemia/terapia , Camundongos , Camundongos Mutantes , Especificidade de Órgãos/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Tirosina Quinases/genética , Transdução Genética , Quinases DyrkRESUMO
The aim of this study was to investigate the effect of selenium supplementation on the antioxidant enzymatic system (such as GPx, GR and SOD), GSH and selenium level in liver, kidney, muscle and brain of static magnetic field (SMF) exposed rats. Male adult rats were divided into control rats (n=6), SMF-exposed rats (128 mT; 1h/day for 5 days), selenium-treated rats (Na(2)SeO(3), 0.2mg/l, in drinking water for 4 weeks) and co-exposed rats (selenium for 4 weeks and SMF during the last 5 consecutive days). Sub-acute exposure to SMF induces a decrease of selenium levels in kidney, muscle and brain. Our results also revealed a decrease of GPx activities in kidney and muscle. By contrast, SMF exposure increased total GSH levels and total SOD activities in liver, while glutathione reductase activity is unaffected. Selenium supplementation in SMF-exposed rats restored selenium levels in kidney, muscle and brain and elevated the activities of GPx in kidney and muscle to those of control group. In the liver, selenium supplementation failed to bring down the elevated levels of total GSH and SOD activity. Our investigations suggested that sub-acute exposure to SMF altered the antioxidant response by decreasing the level of total selenium in kidney, muscle and brain. Interestingly, selenium supplementation ameliorates antioxidant capacity in rat tissues exposed to SMF.
Assuntos
Antioxidantes/metabolismo , Antioxidantes/farmacologia , Campos Eletromagnéticos/efeitos adversos , Selênio/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/efeitos da radiação , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Rim/efeitos dos fármacos , Rim/efeitos da radiação , Fígado/efeitos dos fármacos , Fígado/efeitos da radiação , Masculino , Malondialdeído/metabolismo , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/efeitos da radiação , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismoRESUMO
BACKGROUND: Hyperhomocysteinemia, characterized by increased plasma homocysteine level, is associated with an increased risk of atherosclerosis. On the contrary, patients with Down syndrome appear to be protected from the development of atherosclerosis. We previously found a deleterious effect of hyperhomocysteinemia on expression of DYRK1A, a Down-syndrome-associated kinase. As increased expression of DYRK1A and low plasma homocysteine level have been associated with Down syndrome, we aimed to analyze the effect of its over-expression on homocysteine metabolism in mice. METHODOLOGY/PRINCIPAL FINDINGS: Effects of DYRK1A over-expression were examined by biochemical analysis of methionine metabolites, real-time quantitative reverse-transcription polymerase chain reaction, and enzyme activities. We found that over-expression of Dyrk1a increased the hepatic NAD(P)H:quinone oxidoreductase and S-adenosylhomocysteine hydrolase activities, concomitant with decreased level of plasma homocysteine in three mice models overexpressing Dyrk1a. Moreover, these effects were abolished by treatment with harmine, the most potent and specific inhibitor of Dyrk1a. The increased NAD(P)H:quinone oxidoreductase and S-adenosylhomocysteine hydrolase activities were also found in lymphoblastoid cell lines from patients with Down syndrome. CONCLUSIONS/SIGNIFICANCE: Our results might give clues to understand the protective effect of Down syndrome against vascular defect through a decrease of homocysteine level by DYRK1A over-expression. They reveal a link between the Dyrk1a signaling pathway and the homocysteine cycle.
Assuntos
Regulação da Expressão Gênica , Homocisteína/sangue , Homocisteína/química , Fígado/metabolismo , Metionina/química , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/fisiologia , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/fisiologia , Animais , Feminino , Genótipo , Harmina/farmacologia , Linfócitos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fatores de Risco , Quinases DyrkRESUMO
The concentration of polyamines in red blood cells (RBCs) is considered to be an index of cell proliferation. This index has been demonstrated to be of clinical importance for the follow-up and treatment of some cancer patients. The concentration of polyamines in RBCs is usually determined by high-performance liquid chromatography (HPLC) with fluorescence detection. In the current work, we present a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of putrescine, spermidine, and spermine, the three major polyamines in RBCs. The polyamines were dansylated and analyzed by an LC gradient of 20-min duration on a C18 column on-line with a tandem mass spectrometer. An internal standard (1,8-diaminooctane) was used for quantification. This method exhibited excellent linearity for the three polyamines with regression coefficients higher than 0.99. The limits of detection for putrescine, spermidine, and spermine were 0.10, 0.75, and 0.50 pmol/ml, respectively. The intrarun precision values for putrescine, spermidine, and spermine all were better than 10%, and the interrun precision values were 13%, 9%, and 20%, respectively. The LC-MS/MS method is sufficiently simple and reliable enough to replace the currently used HPLC method with fluorescence detection in which putrescine is not always detectable.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Compostos de Dansil/química , Eritrócitos/química , Poliaminas/análise , Espectrometria de Massas em Tandem/métodos , Humanos , Poliaminas/química , Putrescina/análise , Putrescina/química , Espectrometria de Fluorescência , Espermidina/análise , Espermidina/química , Espermina/análise , Espermina/químicaRESUMO
Hyperhomocysteinemia is characterized by an increase of plasma homocysteine, a thiol-containing amino acid produced during methionine metabolism. Hyperhomocysteinemia has often been associated with coronary artery disease, vascular thrombosis and the development of premature atherosclerosis. We have recently demonstrated that the supplementation of catechin, a polyphenol found in the red wine, significantly reduced plasma homocysteine level in cystathionine beta synthase (CBS) deficient mice, a murine model of hyperhomocysteinemia. In the present study, we have investigated the influence of another well-studied polyphenol found in red wine, resveratrol, on hyperhomocysteinemia. After two months on high methionine diet, heterozygous Cbs deficient mice were administrated the resveratrol in drinking water (0.001%) for one month. High methionine diet significantly increased serum homocysteine levels, and decreased the serum activity of HDL-associated enzyme paraoxonase-1. Chronic administration of resveratrol significantly increased plasma homocysteine level, which was associated with a decreased serum paraoxonase-1 activity, in hyperhomocysteinemic mice. Then we looked at gene expression of several proteins involved in HDL stability and found a down-regulation of lecithin:cholesterol acyltransferase. In conclusion, we found a deleterious effect of resveratrol onto homocysteine and HDL metabolism in a murine model of hyperhomocysteinemia.
Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Metabolismo dos Lipídeos/genética , Fígado/efeitos dos fármacos , Fígado/metabolismo , Estilbenos/farmacologia , Animais , Apolipoproteína A-I/genética , Apolipoproteína A-I/metabolismo , Cistationina beta-Sintase/metabolismo , Suplementos Nutricionais , Genótipo , Hiper-Homocisteinemia/genética , Hiper-Homocisteinemia/metabolismo , Camundongos , Fosfatidilcolina-Esterol O-Aciltransferase/metabolismo , Resveratrol , S-Adenosil-Homocisteína/metabolismo , S-Adenosilmetionina/metabolismo , Receptores Depuradores Classe B/genética , Receptores Depuradores Classe B/metabolismoRESUMO
BACKGROUND: Folate deficiency associated with hyperhomocysteinemia might increase the risk of developing colorectal cancer. The aim of this study was to evaluate factors associated with colonic carcinogenesis, in particular, folate and homocysteinemia levels, in a cross-sectional study of patients with inflammatory bowel disease (IBD). METHODS: IBD patients with carcinogenic lesions discovered during colonoscopy [dysplasia-associated lesion or masses (DALM), colorectal cancer] were included and compared with the whole population of IBD patients with a normal colonoscopy performed during the same period. The following parameters were collected at the time of colonoscopy: age, sex, type, duration, activity, and extent of the disease, treatment, smoking status, and vitamin B12, folate, and homocysteinemia levels. Univariate and multivariate analyses were performed after adjusting for the main parameters. RESULTS: One hundred and fourteen patients [41 with ulcerative colitis (UC), 73 with Crohn's disease (CD)] were included. Twenty-six carcinogenic lesions were isolated: 18 DALM (7 high-grade and 11 low-grade dysplasia) and 8 colorectal cancers. In univariate analysis, the factors associated with carcinogenesis were: active smoking (P = 0.03), folate level < 145 pmol/L (P = 0.02), hyperhomocysteinemia > 15 micromol/L (P = 0.003), duration of disease > 10 years (P = 0.006), and UC (P = 0.02). In multivariate analysis, patients with hyperhomocysteinemia associated with folate deficiency had 17 times as many carcinogenic lesions as patients with normal homocysteinemia whatever the folate status and duration of the disease (P = 0.01). Patients with hyperhomocysteinemia without folate deficiency had 2.5 times as many carcinogenic lesions as patients with normal homocysteinemia (P = 0.08). CONCLUSIONS: Our data suggest that in IBD patients with normal homocysteinemia, the increase in carcinogenic risk is negligible. Conversely, in patients with hyperhomocysteinemia, folate deficiency may be associated with increased colorectal carcinogenesis in IBD patients.
Assuntos
Neoplasias do Colo/etiologia , Deficiência de Ácido Fólico/complicações , Hiper-Homocisteinemia/complicações , Doenças Inflamatórias Intestinais/complicações , Adulto , Neoplasias do Colo/epidemiologia , Neoplasias do Colo/patologia , Estudos Transversais , Feminino , França/epidemiologia , Humanos , Modelos Logísticos , Masculino , Análise Multivariada , Fatores de RiscoRESUMO
BACKGROUND: This study investigates the relationship between the burn-induced oxidative stress and the selenium status. METHODS: The rats were fed with a selenium-adequate diet or a selenium-depleted diet for 5 weeks, before a third-degree thermal injury was applied to the animals. One group of selenium-depleted animals received injections of sodium selenite after the injury. The selenium status and the oxidative stress parameters were measured for 5 days. RESULTS: The selenium-deficient diet leads to oxidative stress with a high stimulation of the superoxide dismutase activity. After the burn injury, the oxidative stress appears important because the initial selenium status is already impaired and, in all animals, the selenium levels and the antioxidant seleno-dependent glutathione peroxidase (GPx) activity decrease in the plasma and the tissues. A treatment with daily selenium injections is efficient in normalizing selenium levels and restores the GPx activity, but fails to counteract the initial oxidative damages induced by the selenium-deficient diet. CONCLUSIONS: The selenium status before the burn injury is a modulating factor of the burn-induced oxidative stress. A single selenium supplement is not sufficient to counteract these oxidative damages and henceforth combined antioxidant supplementations should be investigated to improve the early treatment of the burn patients.
Assuntos
Queimaduras/fisiopatologia , Estresse Oxidativo/fisiologia , Selênio/deficiência , Selenito de Sódio/farmacologia , Animais , Glutationa/sangue , Glutationa Peroxidase/sangue , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/fisiologia , Masculino , Necessidades Nutricionais , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Superóxido Dismutase/sangue , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
There is currently of a great interest investigating the role of nutrition in the prevention of age-associated disorders. The present study aimed to evaluate, on a particular strain of mice, the efficacy of alternate-day fasting on the mitochondrial production of free radical species and on the incidence of a specific cancer (lymphoma) in aged mice. Alternate fasting, that was initiated in middle age mice through a 4 month period, reduced significantly the incidence of lymphoma (0% versus 33% for controls). No remarkable difference was observed in the overall food consumption between alternate-fed (AF) and ad libitum (AL) mice, suggesting that the efficacy of alternate fasting did not really depend on calorie restriction. A significant decrease in the mitochondrial generation of reactive oxygen species (ROS) that was associated with a significant increase in spleen mitochondria SOD activity was observed when mice were maintained on intermittent fasting. Our results suggest that alternate fasting could exert a beneficial antioxidant effect and a modulation of the oxidative stress associated with aging.
Assuntos
Envelhecimento/fisiologia , Jejum , Linfoma/metabolismo , Mitocôndrias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Catalase/metabolismo , Ingestão de Alimentos , Feminino , Radicais Livres/metabolismo , Glutationa Peroxidase/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos , Baço/enzimologia , Superóxido Dismutase/metabolismoRESUMO
Prospective epidemiological studies have shown that the incidence of numerous cardiovascular pathologies is correlated with body selenium status. However, it remains unclear whether selenium status also influences the outcome of myocardial infarction. The aim of the present study was to test whether dietary selenium intake affects myocardial necrosis induced by transient regional ischemia in vivo in rats. For this purpose, male Wistar rats received either a high-selenium (High-Se: 1.5 mg of Se/kg) or a low-selenium (Low-Se: 0.05 mg of Se/kg) diet for 10 weeks. Animals were subjected to 30 min of myocardial ischemia induced by coronary artery ligation followed by 60 min of reperfusion. Pre- and postischemic blood samples were collected for glutathione (GSH and GSSG) determination and for glutathione peroxidase (GSH-Px) assessment. Our results show that high-selenium intake reduces myocardial infarct size (High-Se: 25.16 +/- 1.19% versus Low-Se: 36.51 +/- 4.14%, p < 0.05), preserves postischemic GSH/GSSG ratio (High-Se: 1.37 +/- 0.37 versus Low-Se: 0.47 +/- 0.10, p < 0.05), increases plasma GSH-Px activity, and improves postischemic mean arterial pressure. In conclusion, preischemic body selenium status is a major determinant of the outcome of myocardial ischemia in vivo in rats probably because it influences the cellular redox status.
Assuntos
Infarto do Miocárdio/patologia , Isquemia Miocárdica/metabolismo , Selênio/sangue , Animais , Pressão Sanguínea , Dieta , Glutationa/sangue , Glutationa Peroxidase/sangue , Humanos , Masculino , Oxirredução , Distribuição Aleatória , Ratos , Ratos Wistar , Selênio/administração & dosagemRESUMO
BACKGROUND: Previous studies on the effects of alcohol consumption on total plasma homocysteine (tHcy) concentrations showed contradictory results. The conflicting results may derive in part from confounding by the type of alcoholic beverage consumed. OBJECTIVE: The objective of the study was to evaluate in a predominantly wine-drinking French population whether the relation between alcohol consumption and homocysteine concentrations is dependent on the type of alcoholic beverage consumed. DESIGN: In 1996, a cross-sectional study measuring tHcy and red blood cell folate concentrations was conducted in 1196 middle-aged women and men from the French Supplementation with Antioxidant Vitamins and Minerals Study. Intakes of alcohol, energy, coffee, and B vitamins were assessed by 6 separate 24-h dietary records from the previous year. RESULTS: tHcy concentrations were positively associated with wine intake (P = 0.01) in the women and with beer intake in the men (P = 0.002). No association with the consumption of spirits was observed. The association between beer consumption and tHcy concentrations in the men was modified by the consumption of wine; the association was positive in wine drinkers, whereas an inverse trend was seen in those who drank no wine. CONCLUSION: Wine consumption may increase tHcy concentrations, whereas beer consumption seems to have no effect (or even an inverse effect) on tHcy.
Assuntos
Consumo de Bebidas Alcoólicas , Antioxidantes/administração & dosagem , Cerveja , Homocisteína/sangue , Vinho , Adulto , Registros de Dieta , Método Duplo-Cego , Feminino , França , Humanos , Masculino , Pessoa de Meia-Idade , Minerais/administração & dosagem , Minerais/farmacologia , Fatores Sexuais , Vitaminas/administração & dosagem , Vitaminas/farmacologiaRESUMO
BACKGROUND: An elevated plasma total homocysteine (tHcy) concentration seems to increase the risk of cardiovascular disease. OBJECTIVE: We evaluated the determinants of tHcy in healthy French adults. DESIGN: tHcy was measured by HPLC and fluorometric detection in 1139 women and 931 men aged 35-60 y. Subjects were participants of the Supplementation with Antioxidant Vitamins and Minerals Study, which investigates the effects of antioxidant supplementation on chronic diseases. Red blood cell folate (RBCF), plasma vitamins B-6 and B-12, and cardiovascular disease risk factors were also measured. The habitual diet was assessed in 616 subjects. Cross-sectional analyses were adjusted for age, smoking, energy intake, and concentration or intake of folate and vitamin B-6, where appropriate. RESULTS: The mean (+/-SD) tHcy concentration was 8.74 +/- 2.71 micro mol/L in women and 10.82 +/- 3.49 micro mol/L in men. In women, tHcy was positively related to age (P = 0.001), apolipoprotein B (P < 0.01), serum triacylglycerol (P < 0.01), fasting glucose (P = 0.02), and coffee and alcohol consumption (both P < 0.01) and inversely related to RBCF (P = 0.11) and plasma vitamin B-12 (P = 0.08) and vitamin B-6 (P = 0.01) intakes. In men, tHcy was positively associated with body mass index (P = 0.03), blood pressure (P < 0.02), serum triacylglycerol (P < 0.01), fasting glucose (P = 0.01), and energy intake (P < 0.01) and inversely associated with physical activity (P = 0.04), RCBF (P = 0.02), plasma vitamin B-12 (P = 0.09), and dietary fiber (P < 0.01), folate (P = 0.03), and vitamin B-6 (P = 0.09) intakes. CONCLUSION: To control tHcy, decreasing coffee and alcohol consumption may be important in women, whereas increasing physical activity, dietary fiber, and folate intake may be important in men.
Assuntos
Antioxidantes/administração & dosagem , Doenças Cardiovasculares/sangue , Homocisteína/sangue , Minerais/administração & dosagem , Vitaminas/administração & dosagem , Adulto , Envelhecimento , Consumo de Bebidas Alcoólicas , Apolipoproteínas B/sangue , Glicemia/análise , Constituição Corporal , Índice de Massa Corporal , Cromatografia Líquida de Alta Pressão , Café , Fibras na Dieta/administração & dosagem , Suplementos Nutricionais , Ingestão de Energia , Eritrócitos/química , Exercício Físico , Jejum , Feminino , Ácido Fólico/sangue , França , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Caracteres Sexuais , Triglicerídeos/sangue , Vitamina B 12/sangue , Vitamina B 6/sangueRESUMO
There is currently a great interest in the efficiency of micronutrients against age-associated disorders. The present study aimed to evaluate the efficacy of beta-carotene on the incidence of lymphoid neoplasia, a fatal pathology associated with OFI mouse ageing. Beta-carotene, given as a water-dispersible preparation to 8-month-old mice, on a four month follow-up study, significantly reduced the incidence of neoplasm (12.5% versus 50% for controls). Evaluation of the parameters of oxidative stress showed a highly-significant reduction of the antioxidant defenses in the liver of cancer mice when compared to healthy controls (78% decrease in GSH-Px activity and 47% decrease of the ratio GSH/GSSG). Liver GSH-Px activity was 35% higher in old than in young mice, which correlated with higher (41%) plasma Se level. In conclusion beta-carotene improved the antioxidant status of the mice, causing a 4.5-fold increase in the liver GSH/GSSG ratio, an effect which was probably responsible for the lowered incidence of neoplasia observed.
Assuntos
Envelhecimento/metabolismo , Anticarcinógenos/farmacologia , Antioxidantes/farmacologia , Linfoma/prevenção & controle , beta Caroteno/farmacologia , Envelhecimento/sangue , Envelhecimento/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Química Farmacêutica , Eritrócitos/efeitos dos fármacos , Eritrócitos/enzimologia , Feminino , Glutationa Peroxidase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/metabolismo , Linfoma/etiologia , Camundongos , Selênio/sangue , Selênio/metabolismo , Água/química , beta Caroteno/químicaRESUMO
We studied Ca and Mg and trace elements (Zn, Cu, Fe, Mn, Se) in 15 P.K.U. children treated with strict Phe-reduced diet and in a control group. P.K.U. children are significantly lower (p < 0.01) plasma and erythrocyte Se as well as significantly lower (p < 0.01) activities of Glutathione-Peroxidase (GSH-Px), a seleno-dependent enzyme in erythrocytes and in plasma. Concomitantly with defective GSH-Px activities we observe significantly (p < 0.01) increased levels of lipid peroxidation products: malonaldialdehyde (MDA) and organic hydroperoxides (O.H.P.). So, Se supplementation appears to be necessary in low phenylalanine products used in P.K.U. treatment.