Novel bioanalytical strategy using isotope pattern deconvolution and ICP-QMS for the study of iron incorporation in erythrocytes: An insight to better assessment.

Iron is an essential element for human life and its nutritional status in the human body is directly linked to human health. More than 1015 atoms of iron per second are necessary for the maintenance of haemoglobin formation. To predict iron bioavailability three approaches are normally employed: (a) faecal recovery; (b) plasma appearance; and (c) erythrocyte incorporation (the most used). Isotope Pattern Deconvolution (IPD) is a mathematical tool that allows the isolation of distinct isotope signatures from mixtures of natural abundance and enriched tracers. In this work we propose a novel strategy to assess erythrocyte iron incorporation, based on the use of an iron stable isotope (57Fe) and the IPD concept. This strategy allows direct calculation of the exogenous concentration of 57Fe incorporated into RBCs after supplementation. In this way, to determine the mass of iron incorporated into erythrocytes, the unique prediction that must be made is the blood volume, estimate to reproduce the natural dilution of the tracer (57Fe) in the blood. This novel bioanalytical approach was applied for the measurements of iron incorporation and further iron absorption studies in humans, using a group of twelve healthy participants, that should be further evaluated for the assessment of other chemical elements that could be of health concerns and directly impact society.

Can Iron and Polyunsaturated Fatty Acid Supplementation Induce Ferroptosis?

Ferroptosis is a regulated non-apoptotic cell death process triggered by excessive iron-induced lipid peroxidation. Excess intracellular iron promotes lipid peroxidation by increasing reactive oxygen species formation through the Fenton reaction. Thus, iron and polyunsaturated fatty acid intake may trigger ferroptosis under certain conditions. The aims of this review were to compile and examine evidence in the literature for the effects of iron and polyunsaturated fatty acid supplementation on ferroptosis. Omega-6 polyunsaturated fatty acids have relatively greater susceptibility to lipid peroxidation and could, therefore, participate in ferroptosis. By contrast, omega-3 polyunsaturated fatty acids promote intracellular antioxidants synthesis and reduce the formation of hydroperoxides that induce ferroptosis. As intestinal iron absorption is regulated by iron nutritional status, individuals with normal functioning of the hepcidin-ferroportin axis are at low risk of developing iron overload in response to ingestion of iron-rich foods. Therefore, iron supplementation is potentially toxic mainly for the intestinal epithelium and the microbiota. In animal models, iron-rich diets increased oxidative damage, lowered the glutathione concentration within hepatocytes, and downregulated desaturases that synthesize long-chain polyunsaturated fatty acids. These adverse effects of iron supplementation were prevented by omega-3 fatty acid co-supplementation. The impact of food and supplement intake on ferroptosis has seldom been investigated. Scientific evidence still does not allow us to know for sure whether iron and PUFA supplementation are capable of inducing ferroptosis. As the mechanisms that control ferroptosis can determine whether cells proliferate or die, future studies should directly investigate the effects of nutrient supplementation and food intake on the ferroptosis process in different types of cells and tissues.

Nutrients with Antioxidant Properties and Their Effects on Lower-Limb Ulcers: A Systematic Review.

Chronic lower-limb ulcers (LLUs) are ulcers that fail to proceed through an orderly and timely process to produce anatomic and functional integrity. LLUs reduce the quality of life of affected individuals and are a public health problem. The treatment options include medications or surgery. Nutrition therapy is an important adjunct to improve the clinical picture and healing of LLUs. Considering that nutrients with antioxidant properties can improve the process of tissue healing, this systematic review aimed to evaluate the efficacy of antioxidant nutrient supplementation in the treatment of LLUs through randomized clinical trials. This systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses and the Cochrane Handbook for Systematic Reviews of Interventions. The guiding question was-can antioxidant nutrients help in the treatment of chronic LLUs? In total, 1184 articles were found when searching for antioxidant nutrients associated with the most common causes of LLUs. Fourteen articles were included in this review after removing duplicates, studies with topical and/or venous use of antioxidants, and articles published in other languages, except English. Omega-3 fatty acids, magnesium, zinc, vitamins A, C, D, and resveratrol along with probiotics positively improved the ulcer healing. These effects were more significant when there was initially a deficiency of the respective supplemented nutrients. Therefore, correcting and maintaining an adequate nutritional status can improve ulcer healing and contribute to the clinical treatment of patients with LLUs.

The effect of food and nutrients on iron overload: what do we know so far?

There has been no established food and nutrition guidance for diseases characterized by the presence of iron overload (IOL) yet. Hepcidin is a hormone that diminishes iron bioavailability. Its levels increase in response to increased iron stores. Hence, IOL conditions could hypothetically trigger a self-regulatory mechanism for the reduction of the intestinal absorption of iron. In addition, some food substances may modulate intestinal iron absorption and may be useful in the dietary management of patients with IOL. This scoping review aimed to systematize studies that support dietary prescriptions for IOL patients. It was carried out according to the method proposed by the Joanna Briggs Institute and the preferred reporting items for systematic reviews and meta-analyses (PRISMA). Although the need to restrict iron in the diet of individuals with hemochromatosis is quite clear, there is a consensus that IOL diminishes the rate of iron absorption. Reduced iron absorption is also present and has been reported in some diseases with transfusion IOL, in which serum hepcidin is usually high. The consumption of polyphenols and 6-shogaol seems to reduce iron absorption or serum ferritin concentration, while procyanidins do not cause any changes. Vitamin C deficiency is often found in IOL patients. However, vitamin C supplementation and alcohol consumption should be avoided not only because they increase iron absorption, but also because they provoke toxic oxidative reactions when the iron is excessive. Dietary approaches must consider the differences in the pathophysiology and treatment of IOL diseases.

Prevalência de anemia e deficiência de vitamina A e consumo de ferro e de vitamina A entre crianças usuárias do Sistema Único de Saúde na cidade do Rio de Janeiro, Brasil / Prevalence of anemia and vitamin A deficiency and iron and vitamin A intake in children that use the Brazilian Unified National Health System in Rio de Janeiro, Brazil / Prevalencia de anemia, deficiencia de vitamina A, y consumo de hierro y de vitamina A entre niños pacientes del Sistema Único de Salud en la ciudad de Río de Janeiro, Brasil

Estratégias nacionais para o controle de anemia e deficiência de vitamina A em crianças estão baseadas em estimativas de suas prevalências produzidas em âmbito nacional em 2006 com métodos não validados para este grupo etário e com nível de desagregação para macrorregiões. Com o intuito de subsidiar a gestão local para o (re)direcionamento de medidas de controle desses agravos, o presente trabalho apresenta estimativas de sua prevalência e, também, de marcadores de consumo alimentar de fontes de micronutrientes e do uso de suplementos de vitaminas e minerais em amostra probabilística de crianças de 6 a 59 meses, usuárias da atenção básica de saúde do Município do Rio de Janeiro, Brasil (n = 536). Foram coletadas amostras de sangue venoso para análise de hemoglobina, ferritina e retinol sérico e dados sobre o consumo alimentar, o uso de suplementos de vitaminas e minerais e as características sociodemográficas. As prevalências de anemia, anemia ferropriva e deficiência de vitamina A foram de, respectivamente, 13,7%, 5,5% e 13%. Quase todas as crianças haviam consumido alimentos ricos em ferro no dia anterior à entrevista, sendo altas as prevalências de consumo de fontes de origem animal. Somente 49,4% haviam consumido alimentos ricos em vitamina A. As prevalências de uso de algum suplemento, de suplemento com ferro e com vitamina A foram de, respectivamente, 51%, 14,7% e 24,4%. Os resultados apontam a necessidade de redirecionamento das estratégias de prevenção e controle de anemia e deficiência de vitamina A. Estudos futuros são necessários para examinar a evolução desses indicadores, tendo em vista as políticas de austeridade que entraram em vigor nos últimos anos e a crise econômica decorrente da pandemia da COVID-19.

Brazilian national strategies for the control of anemia and vitamin A deficiency in children are based on estimates of their nationwide prevalence rates in 2006 with methods not validated for this age group and with disaggregation at the level of major geographic regions. To back local administrations in (re)directing control measures for these two disorders, the current study presents estimates of their prevalence and markers of dietary intake of sources of micronutrients and use of vitamin and mineral supplements in a probabilistic sample of children 6 to 59 months of age, users of primary healthcare in the city of Rio de Janeiro, Brazil (n = 536). Venous blood samples were drawn for analysis of hemoglobin, ferritin, and serum retinol, besides collection of data on food consumption, use of vitamin and mineral supplements, and sociodemographic characteristics. Prevalence rates for anemia, iron deficiency anemia, and vitamin A deficiency were 13.7%, 5.5%, and 13%, respectively. Nearly all the children had consumed iron-rich food the day before the interview, with high prevalence of animal sources. Only 49.4% had consumed foods high in vitamin A. The prevalence rates for use of any supplement, iron supplements, and vitamin A supplements were 51%, 14.7%, and 24.4%, respectively. The findings point to the need to redirect the strategies for prevention and control of anemia and vitamin A deficiency. Future studies are necessary to examine trends in these indicators, focusing on austerity policies implemented in recent years and the economic crisis resulting from the COVID-19 pandemic.

Las estrategias brasileñas para el control de anemia y deficiencia de vitamina A en niños están basadas en estimaciones de sus prevalencias, producidas en el ámbito nacional en 2006 con métodos no validados para este grupo etario, y con un nivel de desagregación en las macrorregiones. Con el fin de apoyar la gestión local para la (re)orientación de medidas de control de esos problemas de salud, este trabajo presenta estimaciones de su prevalencia y, también, de los marcadores de consumo alimentario de fuentes de micronutrientes y del uso de suplementos de vitaminas y minerales, en una muestra probabilística de niños de 6 a 59 meses, pacientes de atención básica de salud del Municipio de Río de Janeiro, Brasil (n = 536). Se recogieron muestras de sangre venosa para el análisis de hemoglobina, ferritina y retinol sérico, así como datos sobre el consumo alimentario, de suplementos de vitaminas y minerales, así como de características sociodemográficas. Las prevalencias de anemia, anemia ferropénica y deficiencia de vitamina A fueron de, respectivamente, 13,7%, 5,5% y 13%. Casi todos los niños habían consumido alimentos ricos en hierro el día anterior a la entrevista, siendo altas las prevalencias de consumo de fuentes de origen animal. Solamente un 49,4% habían consumido alimentos ricos en vitamina A. Las prevalencias de consumo de algún suplemento, de suplemento con hierro y de suplemento con vitamina A fueron de, respectivamente, 51%, 14,7% y 24,4%. Los resultados apuntan la necesidad de reorientar las estrategias de prevención y control de la anemia y deficiencia de vitamina A. Se necesitan estudios futuros para examinar la evolución de esos indicadores, teniendo en vista las políticas de austeridad que entraron en vigor en los últimos años y la crisis económica a consecuencia de la pandemia de COVID-19.

Impact of Long-Term Supplementation with Fish Oil in Individuals with Non-Alcoholic Fatty Liver Disease: A Double Blind Randomized Placebo Controlled Clinical Trial.

Non-alcoholic fatty liver disease (NAFLD) is a chronic disease affecting up to 25% of the population worldwide. n-3 long-chain polyunsaturated fatty acids (n-3 PUFA) have been associated with improved clinical parameters of NAFLD. Our purpose was to conduct a pilot study to evaluate the effects of n-3 PUFA supplementation in a randomized, double-blind, placebo-controlled clinical study performed on NAFLD individuals diagnosed by ultrasound. Patients received n-3 PUFA (n = 13) or placebo (n = 11) supplementation for six months. Circulating miR-122 expression (determined by quantitative real time-polymerase chain reaction (qRT-PCR), liver fibrosis (FibroScan®), red blood cells (RBC) fatty acids (gas chromatography), and biochemical tests were performed at baseline and after intervention. After the intervention, in the n-3 PUFA group, docosahexaenoic acid (DHA) and omega index increased significantly in RBC (p = 0.022 and p = 0.012, respectively), in addition to a significant reduction in alkaline phosphatase (ALP) (p = 0.002) and liver fibrosis (p = 0.039). However, there was no change in the expression of circulating miR-122 in both groups. Our results showed that omega-3 PUFA were incorporated in erythrocytes after six months of fish oil supplementary intake, and that n-3 PUFA were effective in reducing ALP and liver fibrosis without altering the expression of circulating miR-122 in individuals with NAFLD.

Antioxidant nutrients and hemolysis in sickle cell disease.

Hemolysis is one of the main pathophysiological characteristics of sickle cell disease (SCD) and might cause or could be the result of oxidative stress. Antioxidants are studied in SCD due to their potential to ensure redox balance and minimize deleterious effects on erythrocyte membranes. The objective of this systematic review was to evaluate the efficacy of antioxidant nutrient supplementation on reducing hemolysis in SCD patients through randomized clinical trials. We conducted our study according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses and the Cochrane Handbook for Systematic Reviews of Interventions investigating whether antioxidants could improve the hemolytic status of SCD patients. This study included 587 articles published until April 2020. We reduced this pool to 12 articles by excluding duplicates, reviews, comments, and studies with non-human subjects. Omega-3 fatty acids, vitamin A, and zinc were the antioxidants that reportedly improved the indirect hemolysis parameters such as hemoglobin, hematocrit, mean corpuscular volume, or red blood cells. High-dose vitamin C and E supplementation worsened hemolysis, causing increased reticulocytes, lactate dehydrogenase, indirect bilirubin, and haptoglobin. More intervention studies especially high-quality controlled randomized clinical trials are needed to investigate the effects of antioxidant nutrients in reducing hemolysis in SCD.

Chia oil induces browning of white adipose tissue in high-fat diet-induced obese mice.

Previous research suggests that omega-3 fatty acids from animal origin may promote the browning of subcutaneous white adipose tissue. We evaluated if supplementation with a plant oil (chia, Salvia hispanica L.) rich in alpha-linolenic fatty acid (C18:3; ω-3) would promote browning and improve glucose metabolism in animals subjected to an obesogenic diet. Swiss male mice (n = 28) were divided into 4 groups: C: control diet; H: high-fat diet; HC: animals in the H group supplemented with chia oil after reaching obesity; HCW: animals fed since weaning on a high-fat diet supplemented with chia oil. Glucose tolerance, inflammatory markers, and expression of genes and proteins involved in the browning process were examined. When supplemented since weaning, chia oil improved glucose metabolism and promoted the browning process and a healthier phenotype. Results of this study suggested that chia oil has potential to protect against the development of obesity-related diseases.

Selenium Status and Hemolysis in Sickle Cell Disease Patients.

Sickle cell disease (SCD) is a genetic hemoglobinopathy characterized by chronic hemolysis. Chronic hemolysis is promoted by increased oxidative stress. Our hypothesis was that some antioxidant micronutrients (retinol, tocopherol, selenium, and zinc) would be determinant factors of the degree of hemolysis in SCD patients. We aimed to investigate the nutritional adequacy of these antioxidants and their relationships to hemolysis. The study included 51 adult SCD patients regularly assisted in two reference centers for hematology in the State of Rio de Janeiro, Brazil. Serum concentrations of retinol, alpha-tocopherol, selenium, and zinc were determined by high-performance liquid chromatography or atomic absorption spectrometry. Hematological parameters (complete blood count, reticulocyte count, hemoglobin, direct and indirect bilirubin, total bilirubin, lactate dehydrogenase) and inflammation markers (leukocytes and ultra-sensitive C-reactive protein) were analyzed. A linear regression model was used to test the associations between the variables. Most patients presented selenium deficiency and low selenium consumption. Linear regression analysis showed that selenium is the main determinant of hemolysis among the antioxidant nutrients analyzed. Thus, data from this study suggest that the nutritional care protocols for patients with SCD should include dietary sources of selenium in order to reduce the risk of hemolysis.

Chia oil supplementation changes body composition and activates insulin signaling cascade in skeletal muscle tissue of obese animals.

OBJECTIVE: Chia seed oil is the richest source of plant-based ω-3 fatty acid, α-linolenic acid, but its potential and mechanisms of action to treat obesity are unclear. The aim of the study was to evaluate the effects of chia oil (ChOi) supplementation on body composition and insulin signaling in skeletal muscles of obese mice. METHODS: Male C57 BL/6 mice (n = 8/group) were fed regular control chow or a high-fat diet (HFD) for 135 d. Another HFD group additionally received ChOi from 90 to 135 d. RESULTS: Consumption of ChOi reduced fat mass accumulation and increased lean mass as evidenced by nuclear magnetic resonance. Moreover, obese mice treated with ChOi showed higher tyrosine phosphorylation of insulin receptor substrate 1, greater activation of protein kinase B, and increased translocation of glucose transporter type 4 in skeletal muscle tissue in response to insulin. ChOi supplementation improved glucose levels and insulin tolerance; decreased serum insulin, leptin, and triacylglycerols; and increased blood high-density lipoprotein cholesterol levels. All these effects caused by the use of ChOi seemed to be independent of the resolution of inflammation because the markers of inflammation were not altered in animals fed the HFD. CONCLUSION: The molecular effects observed in muscle tissue together with changes in body composition may have contributed to the increased glucose tolerance and to the healthy phenotype presented by obese animals treated with ChOi.

Identification of a selenium-dependent glutathione peroxidase in the blood-sucking insect Rhodnius prolixus.

The selenium-dependent glutathione peroxidase (SeGPx) is a well-studied enzyme that detoxifies organic and hydrogen peroxides and provides cells or extracellular fluids with a key antioxidant function. The presence of a SeGPx has not been unequivocally demonstrated in insects. In the present work, we identified the gene and studied the function of a Rhodnius prolixus SeGPx (RpSeGPx). The RpSeGPx mRNA presents the UGA codon that encodes the active site selenocysteine (Sec) and a corresponding Sec insertion sequence (SECIS) in the 3' UTR region. The encoded protein includes a signal peptide, which is consistent with the high levels of GPx enzymatic activity in the insect's hemolymph, and clusters phylogenetically with the extracellular mammalian GPx03. This result contrasts with all other known insect GPxs, which use a cysteine residue instead of Sec and cluster with the mammalian phospholipid hydroperoxide GPx04. RpSeGPx is widely expressed in insect organs, with higher expression levels in the fat body. RNA interference (RNAi) was used to reduce RpSeGPx gene expression and GPx activity in the hemolymph. Adult females were apparently unaffected by RpSeGPx RNAi, whereas first instar nymphs showed a three-day delay in ecdysis. Silencing of RpSeGPx did not alter the gene expression of the antioxidant enzymes catalase, xanthine dehydrogenase and a cysteine-GPx, but it reduced the levels of the dual oxidase and NADPH oxidase 5 transcripts that encode for enzymes releasing extracellular hydrogen peroxide/superoxide. Collectively, our data suggest that RpSeGPx functions in the regulation of extracellular (hemolymph) redox homeostasis of R. prolixus.

Pea protein provides a promising matrix for microencapsulating iron.

Worldwide, the most prevalent nutritional deficiency is iron. The strategies for iron supplementation often fail due to poor adherence to supplementation methods contributed to unpleasant sensory characteristics. An alternative is the use of microencapsulated nutrients for home fortification in order to mask undesirable tastes and to allow its release in strategic sites of the gastrointestinal tract. Toward this end, pea protein concentrate was tested as a natural, edible and alternative material and the spray-drying technique was utilized for the preparation of microparticles containing ferrous sulfate. Their physical and chemical characteristics were evaluated. The microparticles had a spherical shape and grooves with an average size ranging between 2 and 3 µm. Analysis by in vitro assays tested the release of iron in simulated salivary and gastric fluids and its intestinal absorption in Caco-2 cells. No dissolution of iron occurred in the salivary medium whereas the sensory analysis showed good acceptance of a product which incorporated 5.5 mg of iron per 100 g portion of food. Thus, the effectiveness of microencapsulation was demonstrated by utilizing a plant protein as an encapsulating matrix for the controlled release of iron and capable of preserving the bioaccessibility of ferrous sulfate.

Vitamin A modulates the expression of genes involved in iron bioavailability.

Iron bioavailability seems to be regulated by vitamin A (VA) but the molecular events involved in this mechanism are not well understood. It is also known that retinoids mediate most of their function via interaction with retinoid receptors, which act as ligand-activated transcription factors controlling the expression of a number of target genes. Here, we evaluated the VA effects on the modulation of the levels of mRNA encoding proteins involved in the iron bioavailability, whether in the intestinal absorption process or in the liver iron metabolism. The expression of genes involved in iron intestinal absorption (divalent metal transporter 1, duodenal cytochrome B, ferroportin 1 FPN1, and ferritin) were evaluated in vitro by treating Caco-2 cells with retinoic acid or in vivo by observing the effects of vitamin A deficiency (VAD) in BALB/C mice. Liver hepcidin and ferritin mRNA levels were upregulated by VAD; however, this condition did not promote any change on the expression of those genes that participate in the iron absorption. Moreover, data from the in vitro analysis showed that VA induced FPN1 gene expression by a hepcidin-independent manner. Therefore, the in vivo results support the idea that VAD may not affect iron absorption but would rather affect iron mobilization mechanisms. On the other hand, our results using Caco-2 cells raises the possibility that VA addition to intestinal epithelium may improve iron absorption through the induction of FPN1 gene expression.