RESUMO
BACKGROUND: Many countries in the nutrition transition have high rates of iron deficiency (ID) and overweight (OW). ID is more common in OW children; this may be due to adiposity-related inflammation reducing iron absorption. OBJECTIVE: We investigated whether weight status predicts response to oral iron supplementation in ID South African children. DESIGN: A placebo-controlled trial of oral iron supplementation (50 mg, 4 × weeks for 8.5 months) was done in ID 6- to 11-year-old children (n=321); 28% were OW or obese. BMI-for-age z-scores (BAZ), hepcidin (in a sub-sample), hemoglobin, serum ferritin (SF), transferrin receptor (TfR), zinc protoporphyrin (ZnPP) and C-reactive protein (CRP) were measured; body iron was calculated from the SF to TfR ratio. RESULTS: At baseline, BAZ correlated with CRP (r=0.201, P<0.001) and CRP correlated with hepcidin (r=0.384, P<0.001). Normal weight children supplemented with iron had significantly lower TfR concentrations at endpoint than the OW children supplemented with iron and the children receiving placebo. Higher BAZ predicted higher TfR (ß=0.232, P<0.001) and lower body iron (ß=-0.090, P=0.016) at endpoint, and increased the odds ratio (OR) for remaining ID at endpoint in both the iron and placebo groups (iron: OR 2.31, 95% CI: 1.13, 4.73; placebo: OR 1.78, 95% CI: 1.09, 2.91). In the children supplemented with iron, baseline hepcidin and BAZ were significant predictors of endpoint TfR, with a trend towards a hepcidin × BAZ interaction (P=0.058). CONCLUSION: South African children with high BAZ have a two-fold higher risk of remaining ID after iron supplementation. This may be due to their higher hepcidin concentrations reducing iron absorption. Thus, the current surge in OW in rapidly developing countries may undercut efforts to control anemia in vulnerable groups. The trial is registered at clinicaltrials.gov as NCT01092377.
Assuntos
Anemia Ferropriva/sangue , Ferro/sangue , Sobrepeso/sangue , Anemia Ferropriva/dietoterapia , Anemia Ferropriva/epidemiologia , Peptídeos Catiônicos Antimicrobianos/metabolismo , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Criança , Suplementos Nutricionais , Feminino , Hemoglobinas/metabolismo , Hepcidinas , Humanos , Inflamação/sangue , Deficiências de Ferro , Masculino , Sobrepeso/dietoterapia , Sobrepeso/epidemiologia , Estudos Prospectivos , Protoporfirinas/sangue , Receptores da Transferrina/sangue , Fatores de Risco , África do Sul/epidemiologia , Transferrina/metabolismoRESUMO
INTRODUCTION: South Africa's evolving burden of disease is challenging due to a persistent infectious disease, burgeoning obesity, most notably among women and rising rates of non-communicable diseases (NCDs). With two thirds of women presenting at their first antenatal visit either overweight or obese in urban South Africa (SA), the preconception period is an opportunity to optimise health and offset transgenerational risk of both obesity and NCDs. METHODS AND ANALYSIS: Bukhali is the first individual randomised controlled trial in Africa to test the efficacy of a complex continuum of care intervention and forms part of the Healthy Life Trajectories Initiative (HeLTI) consortium implementing harmonised trials in Canada, China, India and SA. Starting preconception and continuing through pregnancy, infancy and childhood, the intervention is designed to improve nutrition, physical and mental health and health behaviours of South African women to offset obesity-risk (adiposity) in their offspring. Women aged 18-28 years (n=6800) will be recruited from Soweto, an urban-poor area of Johannesburg. The primary outcome is dual-energy X-ray absorptiometry derived fat mass index (fat mass divided by height2) in the offspring at age 5 years. Community health workers will deliver the intervention randomly to half the cohort by providing health literacy material, dispensing a multimicronutrient supplement, providing health services and feedback, and facilitating behaviour change support sessions to optimise: (1) nutrition, (2) physical and mental health and (3) lay the foundations for healthier pregnancies and early child development. ETHICS AND DISSEMINATION: Ethical approval has been obtained from the Human Ethics Research Committee University of the Witwatersrand, Johannesburg, South Africa (M1811111), the University of Toronto, Canada (19-0066-E) and the WHO Ethics Committee (ERC.0003328). Data and biological sample sharing policies are consistent with the governance policy of the HeLTI Consortium (https://helti.org) and South African government legislation (POPIA). The recruitment and research team will obtain informed consent. TRIAL REGISTRATION: This trial is registered with the Pan African Clinical Trials Registry (https://pactr.samrc.ac.za) on 25 March 2019 (identifier: PACTR201903750173871). PROTOCOL VERSION: 20 March 2022 (version #4). Any protocol amendments will be communicated to investigators, Institutional Review Board (IRB)s, trial participants and trial registries.
Assuntos
Nível de Saúde , Saúde Mental , Criança , Pré-Escolar , Agentes Comunitários de Saúde , Feminino , Humanos , Masculino , Obesidade/prevenção & controle , Gravidez , África do SulRESUMO
BACKGROUND: Information regarding circulating fatty acids (FA) in association with metabolic health in black Africans is scarce, while the usefulness of circulating FAs as biomarkers of dietary fat intake and predictors for medical conditions is increasing. OBJECTIVE: We compared eleven dietary and the levels of 26 plasma phospholipid FAs in metabolically healthy and unhealthy phenotypes in black South African adults. METHODS: Adults from the South African arm of the Prospective Urban and Rural Epidemiology study baseline (n = 711) were categorised into four groups, namely normal weight without metabolic syndrome (MetS) (MHNW), normal weight with MetS (MUNW), metabolically healthy overweight/obese (MHO) and metabolically unhealthy overweight/obese (MUO). Dietary and plasma phospholipid FAs were measured by a quantitative food frequency questionnaire and gas chromatography-tandem mass spectrometry, respectively. We compared dietary FAs, plasma phospholipid FAs, and estimated desaturase activity between the metabolic status groups using ANCOVA adjusted for age and energy intake. RESULTS: MetS was diagnosed in 35% of the participants. After adjustment for age and total energy intake, in comparison to the MHNW reference group, saturated dietary FAs (C14:0 to C18:0) and alpha-linolenic acid intakes were higher in both overweight/obese groups (MHO and MUO), while linoleic acid intakes were higher in the MUO group only. Plasma levels of most saturated FAs (C18:0 to C22:0) and PUFAs were higher, whereas selected MUFAs, palmitic acid, and estimated desaturase activities were lower in the overweight/obese groups. CONCLUSIONS: The overweight groups generally had higher fat intakes than normal-weight groups, but lower plasma levels of palmitic, palmitoleic, oleic, cis-vaccenic and estimated desaturase activities. Therefore, in this population, lower plasma levels of palmitic, palmitoleic, oleic, and cis-vaccenic acids and decreased estimated desaturase activities may be biomarkers of abnormal metabolic health in overweight/obese study participants.
Assuntos
Gorduras na Dieta/sangue , Ácidos Graxos/sangue , Síndrome Metabólica/sangue , Sobrepeso/sangue , Fosfolipídeos/sangue , Adulto , Estudos de Casos e Controles , Estudos Transversais , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Masculino , Síndrome Metabólica/etnologia , Pessoa de Meia-Idade , Sobrepeso/etnologia , Estudos Prospectivos , África do Sul/etnologiaRESUMO
Evidence regarding the relationship of plasma clot properties with fatty acids is contradictory, owing to different experimental protocols employed. The relationship of fibrinogen and plasma fibrin clot properties with plasma phospholipid fatty acids were cross-sectionally investigated in a population-based setting in 900 individuals. Composite saturated fatty acids (driven by stearic acid) and composite n-3 and n-6 polyunsaturated fatty acids (driven by docosahexaenoic and arachidonic acid respectively) were associated with prothrombotic clot properties. Composite monounsaturated fatty acids (driven by oleic acid) were associated with a profibrinolytic clot phenotype. Fibrinogen and BMI partly mediated these relationships. Individual plasma fatty acids from the same composite group had opposing associations with clot properties indicating that associations with composite fatty acid groups is dependent on the relative composition of the comprising fatty acids. The relationship of the plasma phospholipid fatty acid profile with disease should not be interpreted without considering the role of regulatory mechanisms.
Assuntos
Coagulação Sanguínea/fisiologia , Ácidos Graxos/sangue , Fibrina/análise , Fibrinogênio/análise , Fosfolipídeos/sangue , Índice de Massa Corporal , Estudos Transversais , Feminino , Tempo de Lise do Coágulo de Fibrina , Fibrinogênio/química , Humanos , Masculino , Pessoa de Meia-Idade , Nefelometria e Turbidimetria , Concentração Osmolar , África do Sul , Trombose/sangueRESUMO
South Africa (SA) is home to a heterogeneous population with a wide range of cardiovascular risk factors. Cholesterol reduction in combination with aggressive management of modifiable risk factors, including nutrition, physical activity, blood pressure and smoking, can help to reduce and prevent morbidity and mortality in individuals who are at increased risk of cardiovascular events. This updated consensus guide to management of dyslipidaemia in SA is based on the updated European Society of Cardiology and European Atherosclerosis Society dyslipidaemia guidelines published in 2016. For individuals who are not considered to be at high or very high cardiovascular risk, the decision whether to treat and which interventional strategy to use is based on a cardiovascular risk score calculated using total cholesterol, high-density lipoprotein cholesterol (HDL-C), gender, age and smoking status. The cardiovascular risk score refers to the 10-year risk of any cardiovascular event and includes 4 categories of risk (low, moderate, high and very high). People with established cardiovascular disease, diabetes mellitus, chronic kidney disease and genetic or severe dyslipidaemias are considered to already be at high or very high risk and do not require risk scoring. Therapeutic lifestyle change is the mainstay of management for all patients. The need for and intensity of drug therapy is determined according to baseline low-density lipoprotein (LDL-C) levels and the target LDL-C concentration appropriate to the individual. LDL-C treatment targets are based on pre-treatment risk and are as follows: <3 mmol/L in low- and moderate risk cases; <2.5 mmol/L and a reduction of at least 50% if the baseline concentration is 2.5 - 5.2 mmol/L in high-risk cases; and <1.8 mmol/L and a reduction of at least 50% if the baseline concentration is 1.8 - 3.5 mmol/L in very high-risk cases. A statin is usually recommended first-line; the specific agent is based on the required degree of cholesterol reduction, comorbidities and co-prescribed medication. Special attention should be paid to children with a family history of genetic or severe dyslipidaemia, who should be screened for dyslipidaemia from 8 years of age. In SA, HIV infection is not considered to be a significant cardiovascular risk factor and treatment recommendations for HIV-positive individuals are the same as for the general population, with careful choice of pharmacotherapy to avoid potential adverse drug-drug interactions. The benefit of statins in individuals older than 70 years is uncertain and clinical judgement should be used to guide treatment decisions and to avoid side-effects and overmedication in this group.
Assuntos
Doenças Cardiovasculares , Dislipidemias , Inibidores de Hidroximetilglutaril-CoA Redutases , Programas de Rastreamento/métodos , Administração dos Cuidados ao Paciente , Comportamento de Redução do Risco , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/prevenção & controle , Doenças Cardiovasculares/psicologia , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Consenso , Dislipidemias/sangue , Dislipidemias/epidemiologia , Dislipidemias/terapia , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Administração dos Cuidados ao Paciente/métodos , Administração dos Cuidados ao Paciente/normas , Medição de Risco/métodos , Fatores de Risco , África do SulRESUMO
We recently reported that iron supplementation increased respiratory morbidity in iron deficient South African children. This increase, however, was attenuated when iron was provided in combination with a mixture of DHA/EPA. To explore potential underlying mechanisms, we examined the effects of iron and DHA/EPA, alone and in combination, on plasma lipid-derived immune modulator concentrations and related gene expression in peripheral blood mononuclear cells (PBMC). DHA/EPA decreased inflammatory 12-hydroxyeicosatetraenoic acid and tended to increase anti-inflammatory and pro-resolving 17-hydroxydocosahexaenoic acid (17-HDHA), while iron decreased 17-HDHA. However, in combination with iron, the anti-inflammatory effect of DHA/EPA was maintained. These biochemical changes may explain the prevention of iron-induced respiratory morbidity that we observed when iron was supplemented in combination with DHA/EPA during the 8.5 month randomised controlled trial and might lead to a safer approach of delivering iron supplementation. The study was registered at clinicaltrials.gov as NCT01092377.
Assuntos
Ácidos Docosa-Hexaenoicos/uso terapêutico , Ácido Eicosapentaenoico/uso terapêutico , Deficiências de Ferro , Ferro/uso terapêutico , Criança , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/administração & dosagem , Método Duplo-Cego , Ácido Eicosapentaenoico/administração & dosagem , Feminino , Humanos , Ferro/administração & dosagem , Masculino , Estresse Oxidativo/efeitos dos fármacos , América do SulRESUMO
Allergy has been associated with altered fatty acid and inflammatory status. In this cross-sectional study of 321 rural iron deficient (ID) South African children (aged 6-11 years), a subsample (n=111) of children with parent-reported allergy data were divided into an allergic (n=30) and non-allergic (n=81) group and compared. PBMC arachidonic acid (ARA; P=0.010) and the PBMC ARA to dihomo-gamma-linolenic acid (DGLA) ratio (P=0.035) were lower in the allergic children. Plasma 12-hydroxyeicosatetraenoic acid and 17-hydroxydocosahexaenoic acid (17-HDHA) were higher (P=0.040 and 0.020, respectively) in the allergic group. Thus, a fatty acid composition and lipid mediator levels indicative of increased release of ARA from PBMC membranes, increased inflammation as well as the resolving thereof, were associated with parent-reported allergy symptoms. This study used baseline data of an intervention study which was registered at clinicaltrials.gov as NCT01092377.
Assuntos
Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico/sangue , Anemia Ferropriva/sangue , Ácido Araquidônico/sangue , Ácidos Docosa-Hexaenoicos/sangue , Hipersensibilidade/epidemiologia , Ácido 8,11,14-Eicosatrienoico/sangue , Criança , Estudos Transversais , Feminino , Humanos , Hipersensibilidade/sangue , Masculino , População Rural , África do SulRESUMO
OBJECTIVE: First, we wanted to dispel the myth that avocados are fattening and therefore should be avoided in energy-restricted diets. Second, we examined the effects of avocados, a rich source of monounsaturated fatty acids, as part of an energy-restricted diet on weight loss, serum lipids, fibrinogen, and vascular function in overweight and obese subjects. METHODS: Sixty-one free-living volunteers (13 men and 48 women), with body mass index of 32 +/- 3.9 kg/m(2) (mean +/- standard deviation) participated in this randomized, controlled, parallel study. Subjects were paired and randomly assigned to one of two groups. The experimental group consumed 200 g/d of avocado (30.6 g of fat), which substituted for 30 g of other mixed dietary fats such as margarine or oil, and the control group excluded avocado from their energy-restricted diet for 6 wk. Seven-day isoenergetic menus were planned according to mean energy requirements of both sexes to provide total energy intakes consisting of 30% fat, 55% carbohydrates, and 15% protein. Anthropometric measurements, physical activity, blood pressure, and arterial compliance were measured with standard methods at the beginning and end of the intervention. Fasting blood samples were drawn at the beginning and end of the intervention. RESULTS: Fifty-five subjects completed the study. The compliance rate to avocado intake in the experimental group was 94.6%. The percentage of plasma oleic acid increased significantly with the consumption of avocado in the experimental group, whereas a decrease was seen in the percentage of myristic acid from baseline to the end of the intervention in both groups but was significant only in the experimental group. Anthropometric measurements (body mass, body mass index, and percentage of body fat) decreased significantly in both groups during the study (P < 0.001), and the change was similar in both groups. Serum lipid concentrations (total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triacylglycerols), fibrinogen, blood pressure, and arterial compliance did not change significantly within or between groups. CONCLUSION: The consumption of 200 g/d of avocado within an energy-restricted diet does not compromise weight loss when substituted for 30 g of mixed dietary fat. Serum lipid concentrations, plasma fibrinogen, arterial compliance, and systolic and diastolic blood pressures were not affected by weight loss or avocado intake.
Assuntos
Dieta Redutora , Gorduras Insaturadas na Dieta/administração & dosagem , Ácidos Graxos Monoinsaturados/administração & dosagem , Lipídeos/sangue , Obesidade/dietoterapia , Persea , Adulto , Pressão Sanguínea/efeitos dos fármacos , Feminino , Fibrinogênio/análise , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Persea/química , Redução de Peso/efeitos dos fármacosRESUMO
The effect of the intake of 3-14 eggs/wk on biochemical risk markers of coronary heart disease (CHD) was examined in 70 young men who followed a high-fat diet. The study consisted of a run-in phase during which all subjects ate 3 eggs/wk for 2 mo and an experimental phase during which a reference group continued eating 3 eggs/wk and two experimental groups ate either 7 or 14 eggs/wk for 5 mo. The mean coefficients of variation in total plasma cholesterol (5.4-7.4%) were similar in all three groups and were larger than the mean changes of 0.2-5.6% in plasma cholesterol from baseline to end in the experimental groups. Except for increased lecithin-cholesterol acyltransferase activities and total serum protein concentrations, no significant differences in lipoproteins or coagulation factors occurred between groups. It seems that egg intake in this range did not influence CHD risk markers in these subjects. Recommendations to lower risk should probably concentrate on a reduction in fat and not cholesterol intake.
Assuntos
Coagulação Sanguínea , Ingestão de Alimentos , Ovos , Lipoproteínas/sangue , Adolescente , Adulto , Colesterol/sangue , Colesterol na Dieta/farmacologia , Gorduras na Dieta/farmacologia , Humanos , Lipídeos/sangue , Masculino , Análise de RegressãoRESUMO
An atherogenic diet (AD) consisting entirely of normal foods for westernized people was fed to female Vervet monkeys for 4 years. The plasma low density lipoprotein (LDL) cholesterol pool was increased and progression of atherosclerosis was enhanced by the AD compared to a more prudent Western diet. The increased LDL-cholesterol was carried by a 3-fold increase in particles of relatively normal composition and not by packing cholesterol esters into the cores of enlarged LDL particles, as has been reported after feeding semisynthetic diets loaded with extra cholesterol. Nevertheless, these LDL particles were atherogenic. The AD changed the fatty acid composition of LDL-cholesterol esters and triacylglycerol, notably by increasing arachidonic and reducing linoleic acid. Multivariate analysis showed that measures and scores of atherosclerosis were significantly dependent on sphingomyelin and phosphatidylcholine in LDL and on arachidonic acid in LDL-triacylglycerol. Although apolipoprotein B, free cholesterol, esterified cholesterol and lysophosphatidylcholine in plasma LDL and atherosclerosis were significantly positively correlated in bivariate analysis they were not selected by multivariate analysis as the strongest determinants of atherogenesis. Cholesterol in plasma high density lipoprotein was not changed by the AD and lecithin:cholesterol acyltransferase activity in plasma was inversely linked to atherosclerosis. Subcutaneous fatty acids reflected dietary fatty acids.
Assuntos
Arteriosclerose/sangue , LDL-Colesterol/sangue , Dieta Aterogênica , Animais , Ácido Araquidônico , Ácidos Araquidônicos/sangue , Chlorocebus aethiops , Feminino , Ácido Linoleico , Ácidos Linoleicos/sangue , Tamanho da PartículaRESUMO
Adding less than 0.5% w/w of culture material of strain MRC 826 of the fungus Fusarium moniliforme to a carbohydrate diet low in fat resulted in an atherogenic plasma lipid profile in a non-human primate. Simultaneously increased plasma fibrinogen and activity of blood coagulation factor VII could enhance atherogenesis. This unique potential for promotion of atherosclerosis was probably secondary to chronic hepatotoxicity as indicated by liver fibrosis and elevated cholesterol, albumin and the enzymes AST, ALT, LD, GGT and ALP in serum. The cholesterol and enzymes responded in proportion to the calculated doses of fumonisin mycotoxins in the F. moniliforme MRC 826 cultures. Fumonisins are water soluble and heat stable. Thrombotic, hepatotoxic, carcinogenic and cerebral effects of MRC 826 culture material and fumonisins are well known in non-primates. The estimated fumonisin concentrations tested fall within a range due to natural contamination of human foods. The results suggest that all maize grain products should be analysed for fumonisins.
Assuntos
Arteriosclerose/etiologia , Carboidratos da Dieta/administração & dosagem , Fusarium , Animais , Chlorocebus aethiops , Colesterol/sangue , Gorduras na Dieta/administração & dosagem , Feminino , Fibrinogênio/análise , Fusarium/metabolismo , Hemostasia , Imunoglobulinas/análise , Fígado/enzimologia , Fígado/metabolismo , Fígado/patologia , Masculino , Micotoxinas/biossíntese , Micotoxinas/toxicidade , Albumina Sérica/análiseRESUMO
This double-blind, cross-over study with olive oil as placebo, examined the effect of a daily dosage of 6 g fish oil on cardiovascular risk markers of 20 healthy young volunteers (10 men, 10 women). Serum lipids and lipoproteins, and plasma coagulation and fibrinolytic enzymes, including fibrinogen concentrations and plasminogen activator inhibitor-1 (PAI-1) activity were measured at baseline and after 6-week supplementation of either fish or olive oil. The results showed that fish oil had an independent lowering effect on triglycerides and coagulation factors Vc and VIIc. Both fish and olive oil significantly raised PAI-1 levels and lowered plasma factor Xc and fibrinogen levels in the women, who had higher initial levels than the men. Mean fibrinogen levels of the women were lowered from 3.23 +/- 0.98 to 2.64 +/- 0.55 g/l and from 3.19 +/- 0.72 to 2.66 +/- 0.49 g/l by fish and olive oil respectively. This study raises the question whether a particular fatty acid or group of fatty acids, or another constituent of the oil such as vitamin E may be responsible for the fibrinogen lowering effect.
Assuntos
Fibrinogênio/análise , Óleos de Peixe/farmacologia , Óleos de Plantas/farmacologia , Administração Oral , Adulto , Fatores de Coagulação Sanguínea/análise , Índice de Massa Corporal , Cápsulas , Doenças Cardiovasculares/epidemiologia , Estudos Cross-Over , Método Duplo-Cego , Ácidos Graxos/análise , Feminino , Óleos de Peixe/administração & dosagem , Óleos de Peixe/química , Humanos , Estilo de Vida , Masculino , Azeite de Oliva , Óleos de Plantas/administração & dosagem , Óleos de Plantas/química , Fatores de Risco , Fatores Sexuais , Triglicerídeos/sangue , Vitaminas/análiseRESUMO
We review the hepatocarcinogenic effects of fungal cultures of Fusarium verticillioides(= Fusarium moniliforme) strain MRC 826 in male BD IX rats. Subsequent chemical analyses of the fumonisin B (FB) mycotoxin content in the culture material used and long-term carcinogenesis studies with purified FB1 provide information about dose-response effects, relevance of hepatotoxicity during FB1-induced carcinogenesis, and the existence of a no-effect threshold. Fumonisin intake levels of between 0.08 and 0.16 mg FB/100 g body weight (bw)/day over approximately 2 years produce liver cancer in male BD IX rats. Exposure levels < 0.08 mg FB/100 g bw/day fail to induce cancer, although mild toxic and preneoplastic lesions are induced. The nutritional status of the diets used in the long-term experiments was marginally deficient in lipotropes and vitamins and could have played an important modulating role in fumonisin-induced hepatocarcinogenesis. Short-term studies in a cancer initiation/promotion model in rat liver provided important information about the possible mechanisms involved during the initial stages of cancer development by this apparently nongenotoxic mycotoxin. These studies supported the findings of long-term investigations indicating that a cytotoxic/proliferative response is required for cancer induction and that a no-effect threshold exists for cancer induction. The mechanisms proposed for cancer induction are highlighted and include the possible role of oxidative damage during initiation and the disruption of lipid metabolism, integrity of cellular membranes, and altered growth-regulatory responses as important events during promotion.
Assuntos
Ácidos Carboxílicos/toxicidade , Carcinógenos Ambientais/toxicidade , Fumonisinas , Neoplasias Hepáticas Experimentais/induzido quimicamente , Micotoxinas/toxicidade , Fenômenos Fisiológicos da Nutrição Animal , Animais , Peso Corporal/efeitos dos fármacos , Ácidos Carboxílicos/isolamento & purificação , Carcinógenos Ambientais/isolamento & purificação , Células Cultivadas , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Ácidos Graxos Insaturados/metabolismo , Fusarium/química , Fusarium/classificação , Lipídeos/biossíntese , Neoplasias Hepáticas Experimentais/metabolismo , Masculino , Micotoxinas/isolamento & purificação , Fosfolipídeos/metabolismo , RatosRESUMO
The kinetics of fatty acid (FA) replacement in different membrane compartments in the rat liver were investigated using diets with varying n-6/n-3 FA ratios. Rats at different stages of growth, i.e. after weaning and at 150 g body weight, were either fed a modified AIN 76A diet containing sunflower oil as fat source or the same diet containing sunflower oil and fish oil to achieve n-6/n-3 FA ratios of 12:1 and 6:1 (diets A and B, respectively). In the adult rats, fed diet A for 8 weeks, C18:2n-6 increased significantly at week 2 in the phosphatidylcholine (PC) fraction of the plasma membranes, microsomes and plasma but not in phosphatidylethanolamine (PE), C20:3n-6 increased significantly at week 2 in the plasma membrane and microsomal PC, but did only increased in PE of both compartments by week 8. C20:4n-6 and the n-3 FAs significantly decreased and increased, respectively, at week 2 in PC and PE of both membrane compartments and plasma PC. The experimental diets led to a change in the plasma membrane fluidity but not in the microsomes. The FA changes in the weaned rats followed a similar pattern as in the adult rats although the changes were greater, depending on the phospholipid fraction and specific FA. The decrease in C20:4n-6 was significantly greater in the microsomal PC and PE and plasma PC but not in the plasma membrane PC and PE. The n-3 FAs increased significantly above the adult levels in the plasma membrane PC and PE respectively but not in the microsomal phospholipid fractions. A plateau for maximal n-3 and n-6 FA incorporation was achieved in the adult rats fed diet A in the microsomes after 2 weeks with no further alterations occurring with diet B. In the plasma PC and plasma membranes most of the n-3 FAs achieved a threshold incorporation after 2 weeks on diet A, except for C22:6n-3 in the plasma membranal PE and certain n-6 FAs in the plasma membrane PC and PE. The present data shows that differences exist in the kinetics of FA incorporation and replacement depending on the specific phospholipid fraction, membrane compartment, age and to a certain extent the dietary n-6/n-3 FA ratio.
Assuntos
Gorduras Insaturadas na Dieta/metabolismo , Ácidos Graxos Insaturados/metabolismo , Fígado/metabolismo , Envelhecimento , Animais , Peso Corporal , Membrana Celular/química , Membrana Celular/metabolismo , Colesterol/sangue , Dieta , Gorduras Insaturadas na Dieta/administração & dosagem , Ácidos Graxos Ômega-3/química , Ácidos Graxos Ômega-3/metabolismo , Ácidos Graxos Ômega-6 , Ácidos Graxos Insaturados/administração & dosagem , Ácidos Graxos Insaturados/química , Óleos de Peixe/química , Óleos de Peixe/metabolismo , Cinética , Fluidez de Membrana/fisiologia , Lipídeos de Membrana/química , Lipídeos de Membrana/metabolismo , Microssomos Hepáticos/química , Microssomos Hepáticos/metabolismo , Tamanho do Órgão , Fosfolipídeos/sangue , Fosfolipídeos/química , Fosfolipídeos/metabolismo , Óleos de Plantas/química , Óleos de Plantas/metabolismo , Ratos , Ratos Endogâmicos F344 , Óleo de Girassol , ViscosidadeRESUMO
Severe iron deficiency was introduced in rats by feeding outbred male Wistar rats a purified diet that was either adequate or deficient in iron. The rats were weighed regularly over 4 weeks to monitor body weight differences, after which blood was drawn from a subsample to determine the haemoglobin concentrations and fatty acid composition of plasma total phospholipids and to measure the erythrocyte membrane phosphatidylcholine and phosphatidylethanolamine levels. Comparisons between dietary iron adequate (control) and dietary iron deficient (experimental) rats showed that the experimental rats had lower body weight and plasma total phospholipid linoleic acid levels typical of the symptoms of essential fatty acid deficiency. Erythrocyte membrane phosphatidylethanolamine arachidonic acid levels were increased (P < 0.05) with concomitant decreases in oleic acid (P < 0.01). Correlations between fatty acids and growth suggest that the mechanism whereby iron deficiency affects growth is in some way related to abnormal fatty acid shifts that disturb the delicate balance of essential fatty acids in membranes. Additional omega 3 and omega 6 fatty acids may be necessary to counteract the effect of iron deficiency in rats.
Assuntos
Membrana Eritrocítica/química , Ácidos Graxos/sangue , Deficiências de Ferro , Ferro da Dieta/administração & dosagem , Fosfolipídeos/sangue , Animais , Gorduras Insaturadas na Dieta/administração & dosagem , Ácidos Graxos/análise , Ácidos Graxos Essenciais/administração & dosagem , Ácidos Graxos Essenciais/sangue , Ácidos Graxos Essenciais/deficiência , Ácidos Graxos Ômega-3/administração & dosagem , Transtornos do Crescimento/sangue , Transtornos do Crescimento/etiologia , Masculino , Fosfolipídeos/química , Ratos , Ratos WistarRESUMO
The mitoinhibitory effect of fumonisin B1 (FB1) on the mitogenic response of epidermal growth factor (EGF) was investigated in primary hepatocyte cultures with respect to the alterations in the omega6 fatty acid metabolic pathway. Fatty acid analyses of hepatocytes showed that EGF treatment resulted in a significant decrease in the relative levels of 20:4omega6 (arachidonic acid) and an increase in 18:2omega6 (linoleic acid). Supplementation of the hepatocyte cultures with 20:4omega6 in the absence of EGF resulted in an increase in the total omega6 and omega6/omega3 fatty acid ratio. Addition of 20:5omega3 (eicosapentaenoic acid) resulted in an increase of the relative levels of the long chain omega3 fatty acids at the expense of the omega6 fatty acids. When 20:4omega6 and 20:5omega3 was added in the presence of EGF, the mitogenic response of EGF was increased and decreased respectively. When compared to the fatty acid profiles in the absence of EGF, the decreased mitogenic response coincided with a decrease of total omega6 fatty acids and total polyunsaturated fatty acids (PUFA). In addition, the saturated and mono-unsaturated fatty acids increased and the polyunsaturated/saturated (P/S) fatty acid ratio decreased which implied a more rigid membrane structure. Addition of prostaglandin E2 (PGE2) and prostaglandin E1 (PGE1) stimulated and inhibited the mitogenic response respectively. Ibuprofen, a known cyclooxygenase inhibitor, and FB1 inhibited the EGF-induced mitogenic response in a dose-dependent manner. The mitoinhibitory effect of FB1 on the EGF response was counteracted by the addition of PGE2. FB1 also disrupts the omega6 fatty acid metabolic pathway in primary hepatocytes, resulting in the accumulation of C18:2omega6 in phospatidylcholine and triacylglicerol. The disruption of the omega6 fatty acid metabolic pathway and/or prostaglandin synthesis is likely to be an important event in the mitoinhibitory effect of FB1 on growth factor responses.
Assuntos
Ácidos Carboxílicos/toxicidade , Ácidos Graxos/biossíntese , Fumonisinas , Fígado/efeitos dos fármacos , Fígado/metabolismo , Micotoxinas/toxicidade , Alprostadil/farmacologia , Animais , Ácido Araquidônico/metabolismo , Carcinógenos Ambientais/toxicidade , Morte Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Dinoprostona/farmacologia , Fator de Crescimento Epidérmico/farmacologia , Ácidos Graxos/farmacologia , Ibuprofeno/farmacologia , Ácido Linoleico/metabolismo , Fígado/citologia , RatosRESUMO
An intervention study was designed to evaluate the fatty acid (FA) status of children aged 6-11 years before and after iron fortification. Iron deficient (ID) and matched controls without ID (n = 30) were selected. All children received soup (160 mL) fortified with 20 mg iron and 100 mg vitamin C for 15 weeks on school days. Measurements before and after intervention included dietary intake, haematological and iron status and FA composition of plasma and erythrocyte membranes (EMBs). The prevalence of low plasma ferritin concentration and transferrin saturation decreased in the ID children by 40% and 56%, respectively, with intervention. Plasma FAs reflected dietary FA intake. In comparison with controls, the ID group presented with increased percentage total saturated FAs (SFAs; p = 0.0002) in their EMB phosphatidylcholine (PC) and reduced percentage total polyunsaturated FAs (PUFAs; p = 0.0037) before intervention. Lower total n-3 FAs (p = 0.0070) including eicosapentaenoic acid (EPA; p = 0.0034), docosapentaenoic acid (DPA; p = 0.0048) and docosahexaenoic acid (DHA; p = 0.0058) were observed in the ID group. The EMB phosphatidylethanolamine (PEA) of the ID children presented with lower percentages of alpha-linolenic acid (ALA; p = 0.0001), EPA (p = 0.0051) and DHA (p = 0.0084) compared to controls before intervention. Iron intervention was associated with an increase (p < 0,05) in the percentage of n-3 FAs in the EMB-PC and -PEA of the ID group to percentages comparable to that in the control group. It appears that iron status can influence FA metabolism of specific n-3 FAs in the EMBs of young children.
Assuntos
Membrana Eritrocítica/efeitos dos fármacos , Membrana Eritrocítica/metabolismo , Ácidos Graxos/sangue , Deficiências de Ferro , Ferro/administração & dosagem , Lipídeos de Membrana/sangue , Criança , Dieta , Ácidos Graxos Ômega-3/sangue , Ácidos Graxos Insaturados/sangue , Feminino , Hemoglobinas/metabolismo , Humanos , Ferro/sangue , Masculino , Transferrina/metabolismoRESUMO
There is controversy about whether supplementing diets with marine fish oil can regress, promote or prevent atherosclerosis. Therefore the effects of an Atlantic pilchard oil (FO) supplement and dietary change were measured in a proven atherosclerosis model. Vervet or African Green monkeys were fed an atherogenic diet (AD) for long enough to ensure progression before treatments started. Matched groups were then treated for 20 months, either by adding FO to the AD (AD/FO), or by changing to a therapeutic diet with FO (TD/FO). Control treatments consisted of supplementing with sunflower oil (SO) instead of FO, so that treatments were AD/SO and TD/SO. The same total polyunsaturates were supplied by the FO and SO and the dose of FO was realistic (2.5% of total energy). A reference group (R) received the TD with no oil supplements. Supplementing with FO did not change the concentrations of total, low or high density lipoprotein cholesterol in plasma. After The AD/FO the intimas of aortas contained more total (p < or = 0.001), free (p < or = 0.05) and esterified (p < or = 0.05) cholesterol, total phospholipid (p < or = 0.01) and sphingomyelin (p < or = 0.05) than after the AD/SO. After FO supplementation eicosapentaenoic acid was significantly higher and arachidonic acid significantly lower in the plasma and aorta intima phosphatidylcholine. None of these changes was anti-atherogenic in terms of atherosclerosis measured in the same individuals (1). Nor did FO increase the efficacy of the TD.
Assuntos
Artérias/química , Arteriosclerose/dietoterapia , Chlorocebus aethiops/metabolismo , Gorduras na Dieta/farmacologia , Óleos de Peixe/farmacologia , Lipídeos/análise , Lipoproteínas/sangue , Animais , Apolipoproteínas/sangue , Arteriosclerose/sangue , Dieta Aterogênica , Gorduras na Dieta/uso terapêutico , Ácidos Graxos/sangue , Feminino , Óleos de Peixe/uso terapêutico , Masculino , Óleos de Plantas/farmacologia , Óleos de Plantas/uso terapêutico , Óleo de GirassolRESUMO
An intervention study was designed to evaluate the fatty acid (FA) status of children aged 6-11 years before and after iron fortification. Iron-deficient (ID) and matched controls without ID (n = 30) were selected. All children received soup (160 ml) fortified with 20 mg iron and 100 mg vitamin C for 15 weeks on school days. Measurements before and after intervention included dietary intake, haematological and iron status and FA composition of plasma and erythrocyte membranes (EMBs). The prevalence of low plasma ferritin concentration and transferrin saturation decreased in the ID children by 40% and 56%, respectively, with intervention. Plasma FAs reflected dietary FA intake. In comparison with controls, the ID group presented with increased percentage total saturated FAs (SFAs; p = 0.0002) in their EMB phosphatidylcholine (PC) and reduced percentage total polyunsaturated FAs (PUFAs; p = 0.0037) before intervention. Lower total n-3 FAs (p = 0.0070), including eicosapentenoic acid (EPA; p = 0.0034), docosapentenoic acid (DPA; p = 0.0048) and docosahexenoic acid (DHA; p = 0.0058), were observed in the ID group. The EMB phosphatidylethanol-amine (PEA) of the ID children presented with lower percentages of alpha-linolenic acid (ALA; p = 0.0001), EPA (p = 0.0051) and DHA (p = 0.0084) compared to controls before intervention. Iron intervention was associated with an increase (p < 0.05) in the percentage of n-3 FAs in the EMB-PC and EMB-PEA of the ID group to percentages comparable to that in the control group. It appears that iron status can influence FA metabolism of specific n-3 FAs in the EMBs of young children.
Assuntos
Membrana Eritrocítica/metabolismo , Ácidos Graxos/sangue , Deficiências de Ferro , Ferro/administração & dosagem , Ácido Ascórbico/administração & dosagem , Criança , Dieta , Gorduras na Dieta/administração & dosagem , Proteínas Alimentares/administração & dosagem , Ingestão de Energia , Ácidos Graxos/administração & dosagem , Ácidos Graxos Ômega-3/sangue , Feminino , Alimentos , Humanos , Ferro/farmacologia , Masculino , Fosfatidilcolinas/sangue , Fosfatidiletanolaminas/sangue , Ácido alfa-Linolênico/sangueRESUMO
Supplementation with essential fatty acids has been shown to prevent the experimentally induced ectopic calcification of the kidneys known as nephrocalcinosis. Male Sprague-Dawley rats were fed a semi-synthetic diet supplemented with different essential fatty acids while being injected for a period of 10 days with calcium glubionate. After 3 weeks their kidneys and aorta were removed and the respective calcium content measured compared to the control, saline injected animals. Lipoic acid-EPA, fish oil (EPA rich) as well as the EPA monoester reduced the calcium concentration of both the kidneys and the aorta towards control values. Lipoic-EPA was the best absorbed of the three compounds and its combination of anti-oxidant together with EPA lowered the calcium content of both the aortas and the kidneys.