Iron Intake and Human Health.

Iron deficiency anemia (IDA) is a global nutritional disorder affecting large population groups in varying magnitudes in different countries [...].

Ferulic acid protects HepG2 cells and mouse liver from iron-induced damage.

Liver as iron storage organ is particularly susceptible to oxidative stress-induced injury from excess iron. Thus, antioxidant therapies are often used to reverse oxidative damage and protect cells and tissues. This study investigated the protective effects of phenolic acids; ferulic acid (FA) and its metabolite, ferulic acid 4-O-sulfate disodium salt (FAS) against oxidative stress under iron overload conditions in mouse and HepG2 cells. Cells were exposed to FA or FAS and then treated with iron-induced oxidative stress complex of 50 µmol/L FAC and 20 µmol/L of 8-hydroxyquinoline 8HQ (8HQ-FAC). Iron dextran was injected intraperitoneally on alternate days for 10 days to induce the iron overload condition in BALB/c mice. The study revealed that the phenolic acids were protective against ROS production, lipid peroxidation and antioxidant depletion in HepG2 cells and liver tissues of BALB/c mice during iron-induced oxidative stress. The protective function of phenolic acids was achieved by the transcriptional activation of nuclear factor erythroid-2-related factor 2 (Nrf2) to regulate antioxidant genes. In conclusion, the study provides evidence that FA has the potential as a therapeutic agent against iron-related diseases such as T2D.

Strategies to increase the bioaccessibility and bioavailability of iron and zinc from cereal products.

Cereal products provide 50 % of iron and 30 % of zinc in the UK diet. However, despite having high content, the bioavailability of minerals from cereals is low. This review discusses strategies to increase mineral bioavailability from cereal-based foods. Iron and zinc are localised to specific tissue structures within cereals; however, the cell walls of these structures are resistant to digestion in the human gastrointestinal tract and therefore the bioaccessibility of these essential minerals from foods for absorption in the intestine is limited. In addition, minerals are stored in cereals bound to phytate, which is the main dietary inhibitor of mineral absorption. Recent research has focused on ways to enhance mineral bioavailability from cereals. Current strategies include disruption of plant cell walls to increase mineral release (bioaccessibility) during digestion; increasing the mineral:phytate ratio either by increasing the mineral content through conventional breeding and/or agronomic biofortification, or by reducing phytate levels; and genetic biofortification to increase the mineral content in the starchy endosperm, which is used to produce white wheat flour. While much of this work is at an early stage, there is potential for these strategies to lead to the development of cereal-based foods with enhanced nutritional qualities that could address the low mineral status in the UK and globally.

Content and Availability of Minerals in Plant-Based Burgers Compared with a Meat Burger.

Increasing numbers of individuals follow plant-based diets. This has sparked interest in the nutritional evaluation of the meat substitute sector. Nutritional understanding of these products is vital as plant-based eating becomes more common. For example, animal products are rich sources of iron and zinc, and plant-based foods could be inadequate in these minerals. The main aim was to analyse the mineral composition and absorption from a range of plant-based meat-free burgers and compare them to a typical beef burger. Total and bioaccessible mineral contents of plant-based burgers and a beef burger were determined using microwave digestion and in vitro simulated gastrointestinal digestion, respectively. Mineral bioavailability was analysed by in vitro simulated gastrointestinal digestion of foods, followed by exposure of Caco-2 cells to the sample digests and assessment of mineral uptake. Mineral quantification for all samples was achieved using inductively coupled ICP-optical emission spectrometry (ICP-OES). The content of minerals varied significantly amongst the burgers. Significantly greater quantities of Fe and Zn were found in the beef burger compared to most meat substitutes. Bioaccessible Fe was significantly higher in the beef compared to most of the plant-based meat alternatives; however, bioavailable Fe of most plant-based burgers was comparable to beef (p > 0.05). Similarly, bioaccessible Zn was significantly (p < 0.001) higher from the beef burger. Moreover, beef was superior regarding bioavailable Zn (p ≤ 0.05-0.0001), with only the mycoprotein burger displaying comparable Zn bioavailability (p > 0.05). Beef is an excellent source of bioaccessible Fe and Zn compared to most plant-based substitutes; however, these plant-based substitutes were superior sources of Ca, Cu, Mg and Mn. The quantity of bioaccessible and absorbable Fe varies dramatically among the meat alternatives. Plant-based burgers have the potential to provide adequate quantities of iron and zinc to those consuming such burgers as part of a varied diet. Thus, guiding consumer choices will depend on the variety of the vegetable constituents and their iron nutritional quality in different burgers.

Phenolic Acids Rescue Iron-Induced Damage in Murine Pancreatic Cells and Tissues.

Iron is an essential element involved in a variety of physiological functions. However, excess iron catalyzes the generation of reactive oxygen species (ROS) via the Fenton reaction. Oxidative stress, caused by an increase in intracellular ROS production, can be a contributory factor to metabolic syndromes such as dyslipidemia, hypertension, and type 2 diabetes (T2D). Accordingly, interest has grown recently in the role and use of natural antioxidants to prevent iron-induced oxidative damage. This study investigated the protective effect of the phenolic acids; ferulic acid (FA) and its metabolite ferulic acid 4-O-sulfate disodium salt (FAS) against excess iron-related oxidative stress in murine MIN6 cells and the pancreas of BALB/c mice. Rapid iron overload was induced with 50 µmol/L ferric ammonium citrate (FAC) and 20 µmol/L 8-hydroxyquinoline (8HQ) in MIN6 cells, while iron dextran (ID) was used to facilitate iron overload in mice. Cell viability was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay, ROS levels were determined by dihydrodichlorofluorescein (H2DCF) cell-permeant probe, iron levels were measured by inductively coupled plasma mass spectrometry (ICP-MS), glutathione, SOD (superoxide dismutase) and lipid peroxidation, and mRNA were assayed with commercially available kits. The phenolic acids enhanced cell viability in iron-overloaded MIN6 cells in a dose-dependent manner. Furthermore, MIN6 cells exposed to iron showed elevated levels of ROS, glutathione (GSH) depletion and lipid peroxidation (p < 0.05) compared to cells that were protected by treatment with FA or FAS. The treatment of BALB/c mice with FA or FAS following exposure to ID increased the nuclear translocation of nuclear factor erythroid-2-related factor 2 (Nrf2) gene levels in the pancreas. Consequently, levels of its downstream antioxidant genes, HO-1, NQO1, GCLC and GPX4, increased in the pancreas. In conclusion, this study shows that FA and FAS protect pancreatic cells and liver tissue from iron-induced damage via the Nrf2 antioxidant activation mechanism.

Intestinal iron bio-accessibility changes by Lignin and the subsequent impact on cell metabolism and intestinal microbiome communities.

The detrimental effects of high concentrations of colonic iron have been linked to intestinal inflammation and microbial dysbiosis. Exploiting chelation against this luminal pool of iron may restore intestinal health and have beneficial impacts on microbial communities. This study aimed to explore whether lignin, a heterogenous polyphenolic dietary component, has iron-binding affinity and can sequester iron within the intestine and thus, potentially modulate the microbiome. Within in vitro cell-culture models, the treatment of RKO and Caco-2 cells with lignin almost abolished intracellular iron import (96% and 99% reduction of iron acquisition respectively) with corresponding changes in iron metabolism proteins (ferritin and transferrin receptor-1) and reductions in the labile-iron pool. In a Fe-59 supplemented murine model, intestinal iron absorption was significantly inhibited by 30% when lignin was co-administered compared to the control group with the residual iron lost in the faeces. The supplementation of lignin into a microbial bioreactor colonic model increased the solubilisation and bio-accessibility of iron present by 4.5-fold despite lignin-iron chelation previously restricting intracellular iron absorption in vitro and in vivo. The supplementation of lignin in the model increased the relative abundance of Bacteroides whilst levels of Proteobacteria decreased which could be attributed to the changes in iron bio-accessibility due to iron chelation. In summary, we demonstrate that lignin is an effective luminal iron chelator. Iron chelation leads to the limitation of intracellular iron import whilst, despite increasing iron solubility, favouring the growth of beneficial bacteria.

Upregulation of Nrf2 Signalling and the Inhibition of Erastin-Induced Ferroptosis by Ferulic Acid in MIN6 Cells.

Ferroptosis is a regulated cell death process characterised by the iron-dependent accumulation of oxidised polyunsaturated fatty acid-containing phospholipids. Its initiation is complicated and involves reactive oxygen species (ROS) and a loss of the activity of the lipid repair enzyme glutathione peroxidase 4 (GPX4). These play critical roles in the development of ferroptotic cell damage by lipid peroxidation. Antioxidant therapy is a promising therapeutic strategy to prevent or even reverse the progression of ferroptosis. This study was designed to demonstrate the protective effect of ferulic acid (FA) against oxidative stress and erastin-mediated ferroptosis in murine MIN6 cells. Cells were treated with FA or its metabolite ferulic acid 4-O-sulfate disodium salt (FAS) and 20 µM of erastin. Cell viability was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay, iron levels were measured by inductively coupled plasma mass spectrometry (ICP-MS), ROS levels were determined by a dihydrodichlorofluorescein (H2DCF) cell-permeant probe, and glutathione and lipid peroxidation were assayed with commercially available kits. The phenolic acids enhanced cell viability in erastin-treated MIN6 cells in a dose-dependent manner. Furthermore, MIN6 cells exposed to erastin alone showed elevated levels of iron and ROS, glutathione (GSH) depletion, and lipid peroxidation (p < 0.05) compared to cells that were protected by co-treatment with FA or FAS. The treatment of MIN6 cells with FA or FAS following exposure to erastin increased the nuclear translocation of nuclear factor erythroid-2-related factor 2 (Nrf2) protein levels. Consequently, levels of its downstream antioxidant proteins, HO-1, NQO1, GCLC, and GPX4, increased. FA and FAS greatly decreased erastin-induced ferroptosis in the presence of the Nrf2 inhibitor, ML385, through the regulation of Nrf2 response genes. In conclusion, these results show that FA and FAS protect MIN6 cells from erastin-induced ferroptosis by the Nrf2 antioxidant protective mechanism.

Cytotoxicity of Fenugreek Sprout and Seed Extracts and Their Bioactive Constituents on MCF-7 Breast Cancer Cells.

Trigonella foenum-graecum L. (fenugreek), a member of the legume family (Fabaceae), is a promising source of bioactive phytochemicals, which explains its traditional use for a variety of metabolic disorders including cancer. The current study aimed to evaluate extracts of fenugreek seeds and sprouts, and some of their constituents, to compare their cytotoxic and antiproliferative activities in MCF-7 breast cancer cells. The extracts were chemically characterised using high-resolution accurate mass liquid chromatography-mass spectrometry to reveal the detection of compounds assigned as flavone C-glycosides including those derived from apigenin and luteolin, in addition to isoflavones. Five different flavones or their glycosides (apigenin, vicenin-2, vitexin, luteolin and orientin) and two isoflavones (daidzein and formononetin) were quantified in the fenugreek extracts. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay using MCF-7 cells treated with fenugreek methanolic extracts showed dose- and time-dependent effects on cell viability. The MCF-7 cancer cells treated with the fenugreek methanolic extracts also displayed increased relative mitochondrial DNA damage as well as suppressed metastasis and proliferation. This study demonstrates the potential anti-cancer effects of fenugreek seeds and sprouts and reveals fenugreek sprouts as an untapped resource for bioactive compounds.

In vitro bioaccessibility and bioavailability of iron from fenugreek, baobab and moringa.

Iron deficiency anaemia (IDA) is a common nutritional disorder worldwide. Sustainable food-based approaches are being advocated to use high and bioavailable dietary iron sources to prevent iron deficiency. The study investigated the bioaccessibility and bioavailability of iron from some plant products. Total iron levels in the samples were measured by inductively coupled plasma optical emission spectrometry (ICP-OES). Fractionation of the iron from the digested extracts was carried out by centrifugation and ultrafiltration. Iron bioavailability was determined using an in vitro simulated peptic-pancreatic digestion, followed by measurement of ferritin in Caco-2 cells. The highest amount of bioaccessible iron was obtained from moringa leaves (9.88% ± 0.45 and 8.44 ± 0.01 mg/100 g), but the highest percentage bioavailability was from baobab fruit pulp (99.7% ± 0.13 and 1.74 ± 0.01 mg/100 g) respectively. All the plant products, except for baobab, significantly inhibited iron uptake from FeSO4 and FAC, with fenugreek sprout being the most inhibitory.

In Vitro Bioaccessibility and Bioavailability of Iron from Mature and Microgreen Fenugreek, Rocket and Broccoli.

Iron deficiency is a global epidemic affecting a third of the world's population. Current efforts are focused on investigating sustainable ways to improve the bioavailability of iron in plant-based diets. Incorporating microgreens into the diet of at-risk groups in populations could be a useful tool in the management and prevention of iron deficiency. This study analysed and compared the mineral content and bioavailability of iron from microgreen and mature vegetables. The mineral content of rocket, broccoli and fenugreek microgreens and their mature counterparts was determined using microwave digestion and ICP-OES. Iron solubility and bioavailability from the vegetables were determined by a simulated gastrointestinal in vitro digestion and subsequent measurement of ferritin in Caco-2 cells as a surrogate marker of iron uptake. Iron contents of mature fenugreek and rocket were significantly higher than those of the microgreens. Mature fenugreek and broccoli showed significantly (p < 0.001) higher bioaccessibility and low-molecular-weight iron than found in the microgreens. Moreover, iron uptake by Caco-2 cells was significantly higher only from fenugreek microgreens than the mature vegetable. While all vegetables except broccoli enhanced FeSO4 uptake, the response to ferric ammonium citrate (FAC) was inhibitory apart from the mature rocket. Ascorbic acid significantly enhanced iron uptake from mature fenugreek and rocket. Microgreen fenugreek may be bred for a higher content of enhancers of iron availability as a strategy to improve iron nutrition in the populace.

Anemia of Inflammation with An Emphasis on Chronic Kidney Disease.

Iron is vital for a vast variety of cellular processes and its homeostasis is strictly controlled and regulated. Nevertheless, disorders of iron metabolism are diverse and can be caused by insufficiency, overload or iron mal-distribution in tissues. Iron deficiency (ID) progresses to iron-deficiency anemia (IDA) after iron stores are depleted. Inflammation is of diverse etiology in anemia of chronic disease (ACD). It results in serum hypoferremia and tissue hyperferritinemia, which are caused by elevated serum hepcidin levels, and this underlies the onset of functional iron-deficiency anemia. Inflammation is also inhibitory to erythropoietin function and may directly increase hepcidin level, which influences iron metabolism. Consequently, immune responses orchestrate iron metabolism, aggravate iron sequestration and, ultimately, impair the processes of erythropoiesis. Hence, functional iron-deficiency anemia is a risk factor for several ailments, disorders and diseases. Therefore, therapeutic strategies depend on the symptoms, severity, comorbidities and the associated risk factors of anemia. Oral iron supplements can be employed to treat ID and mild anemia particularly, when gastrointestinal intolerance is minimal. Intravenous (IV) iron is the option in moderate and severe anemic conditions, for patients with compromised intestinal integrity, or when oral iron is refractory. Erythropoietin (EPO) is used to treat functional iron deficiency, and blood transfusion is restricted to refractory patients or in life-threatening emergency situations. Despite these interventions, many patients remain anemic and do not respond to conventional treatment approaches. However, various novel therapies are being developed to treat persistent anemia in patients.

Programmed Cell-Death by Ferroptosis: Antioxidants as Mitigators.

Iron, the fourth most abundant element in the Earth's crust, is vital in living organisms because of its diverse ligand-binding and electron-transfer properties. This ability of iron in the redox cycle as a ferrous ion enables it to react with H2O2, in the Fenton reaction, to produce a hydroxyl radical (•OH)-one of the reactive oxygen species (ROS) that cause deleterious oxidative damage to DNA, proteins, and membrane lipids. Ferroptosis is a non-apoptotic regulated cell death that is dependent on iron and reactive oxygen species (ROS) and is characterized by lipid peroxidation. It is triggered when the endogenous antioxidant status of the cell is compromised, leading to lipid ROS accumulation that is toxic and damaging to the membrane structure. Consequently, oxidative stress and the antioxidant levels of the cells are important modulators of lipid peroxidation that induce this novel form of cell death. Remedies capable of averting iron-dependent lipid peroxidation, therefore, are lipophilic antioxidants, including vitamin E, ferrostatin-1 (Fer-1), liproxstatin-1 (Lip-1) and possibly potent bioactive polyphenols. Moreover, most of the enzymes and proteins that cascade or interact in the pathway of ferroptosis such as a subunit of the cystine/glutamate transporter xc- (SLC7A11), glutathione peroxidase 4 (GPX4), and the glutamate-cysteine ligase (GCLC) iron metabolism genes transferrin receptor 1 (TfR1) ferroportin, (Fpn) heme oxygenase 1 (HO-1) and ferritin are regulated by the antioxidant response element of the transcription factor, Nrf2. These, as well as other radical trapping antioxidants (RTAs), are discussed in the current review.

A Short Review of Iron Metabolism and Pathophysiology of Iron Disorders.

Iron is a vital trace element for humans, as it plays a crucial role in oxygen transport, oxidative metabolism, cellular proliferation, and many catalytic reactions. To be beneficial, the amount of iron in the human body needs to be maintained within the ideal range. Iron metabolism is one of the most complex processes involving many organs and tissues, the interaction of which is critical for iron homeostasis. No active mechanism for iron excretion exists. Therefore, the amount of iron absorbed by the intestine is tightly controlled to balance the daily losses. The bone marrow is the prime iron consumer in the body, being the site for erythropoiesis, while the reticuloendothelial system is responsible for iron recycling through erythrocyte phagocytosis. The liver has important synthetic, storing, and regulatory functions in iron homeostasis. Among the numerous proteins involved in iron metabolism, hepcidin is a liver-derived peptide hormone, which is the master regulator of iron metabolism. This hormone acts in many target tissues and regulates systemic iron levels through a negative feedback mechanism. Hepcidin synthesis is controlled by several factors such as iron levels, anaemia, infection, inflammation, and erythropoietic activity. In addition to systemic control, iron balance mechanisms also exist at the cellular level and include the interaction between iron-regulatory proteins and iron-responsive elements. Genetic and acquired diseases of the tissues involved in iron metabolism cause a dysregulation of the iron cycle. Consequently, iron deficiency or excess can result, both of which have detrimental effects on the organism.

Iron Deficiency and Iron Homeostasis in Low Birth Weight Preterm Infants: A Systematic Review.

Iron is an essential micronutrient that is involved in many functions in humans, as it plays a critical role in the growth and development of the central nervous system, among others. Premature and low birth weight infants have higher iron requirements due to increased postnatal growth compared to that of term infants and are, therefore, susceptible to a higher risk of developing iron deficiency or iron deficiency anemia. Notwithstanding, excess iron could affect organ development during the postnatal period, particularly in premature infants that have an immature and undeveloped antioxidant system. It is important, therefore, to perform a review and analyze the effects of iron status on the growth of premature infants. This is a transversal descriptive study of retrieved reports in the scientific literature by a systematic technique. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were adapted for the review strategy. The inclusion criteria for the studies were made using the PICO (population, intervention, comparison, outcome) model. Consequently, the systematic reviews that included studies published between 2008-2018 were evaluated based on the impact of iron status on parameters of growth and development in preterm infants.

Curcumin and (-)- Epigallocatechin-3-Gallate Protect Murine MIN6 Pancreatic Beta-Cells Against Iron Toxicity and Erastin-Induced Ferroptosis.

Ferroptosis is a form of programmed cell death that is characterized by lipid peroxidation and is inducible by iron and the accumulation of reactive oxygen species (ROS). It is triggered by erastin but inhibited by antioxidants such as -tocopherol, -carotene, polyphenols, and iron chelators such as deferoxamine (DFO), nitrilotriacetic acid (NTA), and ethylenediaminetetraacetic acid (EDTA). This study investigated the protective effects of two polyphenols, curcumin and (-)- epigallocatechin-3-gallate (EGCG), against iron loading and erastin-mediated ferroptosis in MIN6 cells. Cells were treated with polyphenols before exposure to iron-induced oxidative stress comprising of 20 µmol/L of 8-hydroxyquinoline (8HQ) and 50 µmol/L of ferric ammonium citrate, (FAC) (8HQ+FAC) or Fenton reaction substrate (FS) (30 µmol/L of FeSO4 and 0.5 of mmol/L H2O2) and 20 µmol/L erastin. Cell viability was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay, iron levels were measured by inductively-coupled plasma mass spectrometry (ICP-MS), glutathione and lipid peroxidation were assayed with commercially-available kits. Curcumin and EGCG both significantly protected pancreatic cells against iron-induced oxidative damage. Moreover, both compounds also protected against erastin-induced ferroptosis in pancreatic cells. The polyphenols enhanced cell viability in erastin-treated MIN6 cells in a dose- and time-dependent manner. Furthermore, MIN6 cells exposed to erastin alone showed elevated levels of iron, glutathione (GSH) depletion, glutathione peroxidase 4 (GPX4) degradation and lipid peroxidation (p < 0.05) compared to cells that were protected by pre-treatment with curcumin or EGCG. Taken together, the data identify curcumin and EGCG as novel ferroptosis inhibitors, which might exert their protective effects by acting as iron chelators and preventing GSH depletion, GPX4 inactivation, and lipid peroxidation in MIN6 cells. The implications of the findings on the effects of iron overload and ferroptosis represent a potential therapeutic strategy against iron-related diseases.

Protective Role of Histidine Supplementation Against Oxidative Stress Damage in the Management of Anemia of Chronic Kidney Disease.

Anemia is a major health condition associated with chronic kidney disease (CKD). A key underlying cause of this disorder is iron deficiency. Although intravenous iron treatment can be beneficial in correcting CKD-associated anemia, surplus iron can be detrimental and cause complications. Excessive generation of reactive oxygen species (ROS), particularly by mitochondria, leads to tissue oxidation and damage to DNA, proteins, and lipids. Oxidative stress increase in CKD has been further implicated in the pathogenesis of vascular calcification. Iron supplementation leads to the availability of excess free iron that is toxic and generates ROS that is linked, in turn, to inflammation, endothelial dysfunction, and cardiovascular disease. Histidine is indispensable to uremic patients because of the tendency toward negative plasma histidine levels. Histidine-deficient diets predispose healthy subjects to anemia and accentuate anemia in chronic uremic patients. Histidine is essential in globin synthesis and erythropoiesis and has also been implicated in the enhancement of iron absorption from human diets. Studies have found that L-histidine exhibits antioxidant capabilities, such as scavenging free radicals and chelating divalent metal ions, hence the advocacy for its use in improving oxidative stress in CKD. The current review advances and discusses evidence for iron-induced toxicity in CKD and the mechanisms by which histidine exerts cytoprotective functions.

Ferroptosis: Role of lipid peroxidation, iron and ferritinophagy.

Ferroptosis is a form of regulated cell death that is dependent on iron and reactive oxygen species (ROS) and is characterized by lipid peroxidation. It is morphologically and biochemically distinct and disparate from other processes of cell death. As ferroptosis is induced by inhibition of cysteine uptake or inactivation of the lipid repair enzyme glutathione peroxidase 4 (GPX4), the process is favored by chemical or mutational inhibition of the cystine/glutamate antiporter and culminates in the accumulation of reactive oxygen species (ROS) in the form of lipid hydroperoxides. Excessive lipid peroxidation leads to death by ferroptosis and the phenotype is accentuated respectively by the repletion and depletion of iron and glutathione in cells. Furthermore, oxidized phosphatidylethanolamines (PE) harbouring arachidonoyl (AA) and adrenoyl moieties (AdA) have been shown as proximate executioners of ferroptosis. Induction of ferroptosis due to cysteine depletion leads to the degradation of ferritin (i.e. ferritinophagy), which releases iron via the NCOA4-mediated autophagy pathway. Evidence of the manifestation of ferroptosis in vivo in iron overload mice mutants is emerging. Thus, a concerted synchronization of iron availability, ROS generation, glutamate excess and cysteine deficit leads to ferroptosis. A number of questions on the molecular mechanisms of some features of ferroptosis are highlighted as subjects for future investigations.

Hepcidin suppression in ß-thalassemia is associated with the down-regulation of atonal homolog 8.

Atonal homolog 8 (ATOH8) is defined as a positive regulator of hepcidin transcription, which links erythropoietic activity with iron-sensing molecules. In the present study, we investigated the association between hepcidin and ATOH8 expression in ß-thalassemia. We found that inhibition of hepcidin expression in ß-thalassemia is correlated with reduced ATOH8 expression. Hepatic hepcidin 1 (Hamp1) and Atoh8 mRNA expression were down-regulated in ß-thalassemic mice. Hepcidin (HAMP) and ATOH8 mRNA expression were consistently suppressed in Huh7 cells cultured in medium supplemented with ß-thalassemia patient serum. The Huh7 cells, which were transfected with ATOH8-FLAG expression plasmid and cultured in the supplemented medium, exhibited increased levels of ATOH8 mRNA, ATOH8-FLAG protein, pSMAD1,5,8, and HAMP mRNA. Interestingly, over-expression of ATOH8 reversed the effects of hepcidin suppression induced by the ß-thalassemia patient sera. In conclusion, hepcidin suppression in ß-thalassemia is associated with the down-regulation of ATOH8 in response to anemia. We, therefore, suggest that ATOH8 is an important transcriptional regulator of hepcidin in ß-thalassemia.

Bioavailability of iron multi-amino acid chelate preparation in mice and human duodenal HuTu 80 cells.

Strategies for preventing Fe deficiency include Fe supplementation and Fe fortification of foods. The absorption, metabolism and chemical characteristics of Fe multi-amino acid chelate (IMAAC) are not known. Absorption of IMAAC was compared with FeSO4 in Fe-depleted mice and in vitro chemical studies of the Fe supplement was performed in HuTu 80 cells. Hb repletion study was carried out in Fe-deficient CD1 mice that were fed for 10 d a diet supplemented with ferrous IMAAC or FeSO4. A control group of Fe-replete mice was fed a diet with adequate Fe concentrations throughout the study. Tissues were collected from the mice, and the expression of Fe-related genes was determined by quantitative PCR. Ferric reductase and Fe uptake were evaluated in HuTu 80 cells. Supplementation of the diet with FeSO4 or IMAAC significantly increased Hb levels (P<0·001) in Fe-deficient mice from initial 93·9 (SD 10·8) or 116·2 (SD 9·1) to 191 (SD 0·7) or 200 (SD 0·5) g/l, respectively. Initial and final Hb for the Fe-deficient control group were 87·4 (SD 6·7) and 111 (SD 11·7) g/l, respectively. Furthermore, the liver non-haem Fe of both supplement groups increased significantly (P<0·001). IMAAC was more effective at restoring Fe in the spleen compared with FeSO4 (P<0·005). Gene expression showed the IMAAC supplement absorption is regulated by the body's Fe status as it significantly up-regulated hepcidin (P<0·001) and down-regulated duodenal cytochrome b mRNA (P<0·005), similar to the effects seen with FeSO4. A significant proportion of Fe in IMAAC is reduced by ascorbic acid. Fe absorption in mice and cells was similar for both IMAAC and FeSO4 and both compounds induce and regulate Fe metabolism genes similarly in the maintenance of homeostasis in mice.

In Vitro Iron Availability from Insects and Sirloin Beef.

Interest in the consumption of insects (entomophagy) as an alternative environmentally sustainable source of protein in the diet of humans has recently witnessed a surge. Knowledge of the nutrient composition and, in particular, the bioavailability of minerals from insects is currently sparse. This study evaluated the availability of Fe, Ca, Cu, Mg, Mn, and Zn from four commonly eaten insects and compared these to sirloin beef. Soluble iron from the samples was measured by inductively coupled plasma optical emission spectrometry (ICP-OES). Iron bioavailability was determined using an in vitro simulated peptic-pancreatic digestion, followed by measurement of ferritin (a surrogate marker for iron absorption) in Caco-2 cells. Cricket and sirloin beef had comparably higher levels of Fe, Ca, and Mn than grasshopper, meal, and buffalo worms. However, iron solubility was significantly higher from the insect samples than from beef. The complementation of whole-wheat flour with insect or beef protein resulted in overall decreases in mineral content and iron solubility in the composite mixtures. Collectively, the data show that grasshopper, cricket, and mealworms contain significantly higher chemically available Ca, Cu, Mg, Mn, and Zn than sirloin. However, buffalo worms and sirloin exhibited higher iron bioavailability comparable to that of FeSO4. Commonly consumed insect species could be excellent sources of bioavailable iron and could provide the platform for an alternative strategy for increased mineral intake in the diets of humans.