Search Results (18)

Background/Objectives: Lactoferrin (Lf) is an iron-binding glycoprotein with multiple bioactivities, including promotion of cell proliferation and differentiation, immunomodulation, and antimicrobial activity. Lf, a basic glycoprotein, can bind to α-lactalbumin (α-Lac), an acidic whey protein. The current study aimed to evaluate whether Lf forms protein complexes with α-Lac and proteins/peptides from whey protein hydrolysate (WPH) and nonfat bovine milk powder (MP) and whether forming protein complexes influences resistance to gastrointestinal digestion and affects the bioactivities of Lf in human intestinal epithelial cells (HIECs and differentiated Caco-2 cells). Methods: Lf was blended with α-Lac, WPH, or MP. Assays were conducted to evaluate the bioactivities of proteins (Lf, α-Lac, WPH, or MP) and Lf–protein blends on HIECs and Caco-2 cells. Results: (1) Lf forms complexes with α-Lac and proteins/peptides from WPH and MP; (2) compared with Lf alone, complexed Lf shows greater resistance to in vitro digestion; (3) forming protein complexes does not affect Lf’s binding to the Lf receptor or its uptake by HIECs; and (4) forming protein complexes does not impact Lf’s bioactivities, including the promotion of cell proliferation and differentiation, reduction of cell permeability by upregulating tight-junction proteins, immune modulation through the regulation of IL-18, inhibition of enteropathogenic Escherichia coli growth, and modulation of immune responses to EPEC infection. Conclusions: Lf forms complexes with α-Lac and other milk proteins/peptides from WPH and MP in protein blends, and forming complexes does not affect the functionalities of Lf. Full article

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. Full article

This study aims to design and test different formulations composed of dextran-coated iron oxide nanoparticles (IONPs) loaded with 5-Fluorouracil (5-FU) with varying nanoparticle:drug ratios on colorectal cancer cells. The stable suspension of IONPs s was synthesized by the adapted co-precipitation method. The stable suspension of IONPs was mixed with a solution of dextran and 5-FU solubilized in a saline solution. The final suspensions with optimized ratios of IONP:5-FU in the final suspension were 0.5:1, 1:1, and 1.5:1. The information on the morphology and size distribution of the IONPs suspension and IONP loads with 5-FU was obtained using scanning electron microscopy (SEM). The presence of 5-FU and dextran on the surface of the IONPs was highlighted by energy-dispersive X-ray spectroscopy (EDS) studies. The determination of the surface charge of the nanoparticles in the final suspensions of IONP:5-FU was achieved by measuring the zeta potential (ζ). The hydrodynamic diameter of the resulting suspensions of IONP:5-FU was determined by dynamic light scattering (DLS). A cytocompatibility analysis was performed using Caco-2 (human epithelial colorectal adenocarcinoma) cells. In this research, our goal was to find a relationship between the formulation ratio of nanoparticles and drug, and the cellular response after exposure, as a strategy to increase the efficacy of this drug-delivery system. The nanoparticle uptake and antitumor activity, including modulation of oxidative stress, apoptosis, and proliferation biomarkers, were analyzed. The present study showed that the nanoformulation with the ratio IONP:5-FU 1.5:1 had the highest anti-tumor efficiency. Moreover, decreased MCM-2 expression in Caco-2 cells exposed to dextran-coated iron oxide nanoparticles loaded with 5-FU was demonstrated for the first time. Full article

Previous studies demonstrated that quercetin, a polyphenolic compound, inhibits the transport of iron by down-regulation of ferroportin (FPN1), an iron export protein. We have previously demonstrated that activation of the PI3K signaling pathway by zinc stimulates the intestinal iron uptake and transport by stimulating the expression of iron regulatory protein 2 (IRP2) dependent divalent metal iron transporter 1 (DMT1, apical iron transporter) expression and caudal-related homeobox transcription factor 2 (CDX2) dependent hephaestin (HEPH, basolateral ferroxidase required for iron oxidation) expression, respectively. Since polyphenols are antagonists of the PI3K pathway, we hypothesized that quercetin might inhibit basolateral iron transport via the down-regulation of hephaestin (HEPH). Here in we investigated the effect of quercetin on iron uptake, transport, and expression of iron transporters in intestinal cells. In differentiated Caco-2 cells grown on permeable supports, quercetin inhibited the basolateral iron transport while increasing the iron uptake, possibly due to higher cellular retention. Further, quercetin down-regulated the protein and mRNA expression of HEPH and FPN1 but not that of IRP2 or DMT1. In addition, quercetin also abrogated the zinc-induced Akt, CDX2 phosphorylation, and HEPH expression. Together these results suggest that inhibition of iron transport by quercetin is mediated via the down-regulation of CDX2-dependent HEPH expression via inhibition of the PI3K pathway. Full article

A systematic investigation on the cellular uptake, intracellular dissolution, and in vitro biological effects of ultra-small (<10 nm) iron hydroxide adipate/tartrate coated nanoparticles (FeAT-NPs) was carried out in intestinal Caco-2, hepatic HepG2 and ovarian A2780 cells, and the nucleotide excision repair (NER) deficient GM04312 fibroblasts. Quantitative evaluation of the nanoparticles uptake, as well as their transformation within the cell cytosol, was performed by inductively coupled plasma mass spectrometry (ICP-MS), alone or in combination with high performance liquid chromatography (HPLC). The obtained results revealed that FeAT-NPs are effectively taken up in a cell type-dependent manner with a minimum dissolution after 3 h. These results correlated with no effects on cell proliferation and minor effects on cell viability and reactive oxygen species (ROS) production for all the cell lines under study. Moreover, the comet assay results revealed significant DNA damage only in GM04312 cells. In vivo genotoxicity was further studied in larvae from Drosophila melanogaster, using the eye-SMART test. The obtained results showed that FeAT-NPs were genotoxic only with the two highest tested concentrations (2 and 5 mmol·L⁻¹ of Fe) in surface treatments. These data altogether show that these nanoparticles represent a safe alternative for anemia management, with high uptake level and controlled iron release. Full article

A new iron–casein complex (ICC) has been developed for iron (Fe) fortification of dairy matrices. The objective was to assess the impact of ascorbic acid (AA) on its in vitro bioavailability in comparison with ferrous sulfate (FeSO₄) and ferric pyrophosphate (FePP). A simulated digestion coupled with the Caco-2 cell culture model was used in parallel with solubility and dissociation tests. Under diluted acidic conditions, the ICC was as soluble as FeSO₄, but only part of the iron was found to dissociate from the caseins, indicating that the ICC was an iron chelate. The Caco-2 cell results in milk showed that the addition of AA (2:1 molar ratio) enhanced iron uptake from the ICCs and FeSO₄ to a similar level (p = 0.582; p = 0.852) and to a significantly higher level than that from FePP (p < 0.01). This translated into a relative in vitro bioavailability to FeSO₄ of 36% for FePP and 114 and 104% for the two ICCs. Similar results were obtained from water. Increasing the AA to iron molar ratio (4:1 molar ratio) had no additional effect on the ICCs and FePP. However, ICC absorption remained similar to that from FeSO₄ (p = 0.666; p = 0.113), and was still significantly higher than that from FePP (p < 0.003). Therefore, even though iron from ICC does not fully dissociate under gastric digestion, iron uptake suggested that ICCs are absorbed to a similar amount as FeSO₄ in the presence of AA and thus provide an excellent source of iron. Full article

Iron deficiencies continue to cause significant health problems in vulnerable populations. A good strategy to combat mineral deficiency includes fortification with iron-binding peptides. This research aims to determine the optimal conditions to hydrolyze red tilapia viscera (RTV) using Alcalase 2.4 L and recovery of iron-binding protein hydrolysate. The result showed that under the optimal hydrolysis condition including pH 10, 60 °C, E/S ratio of 0.306 U/g protein, and substrate concentration of 8 g protein/L, the obtained hydrolysate with 42.5% degree of hydrolysis (RTVH-B), displayed the maximal iron-binding capacity of 67.1 ± 1.9%. Peptide fractionation was performed using ultrafiltration and the <1 kDa fraction (FRTVH-V) expressed the highest iron-binding capacity of 95.8 ± 1.5%. Iron content of RTVH-B and its fraction was assessed, whereas iron uptake was measured indirectly as ferritin synthesis in a Caco-2 cell model and the result showed that bioavailability of bound minerals from protein complexes was significantly higher (p < 0.05) than iron salt in its free form, increased 4.7 times for the Fe²⁺–RTVH-B complex. This research suggests a potential application of RTVH-B as dietary supplements to improve iron absorption. Full article

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. Full article

Hummus, an iron-containing plant-based dish mainly made from chickpea purée, tahini, lemon juice and garlic, could be a valuable source of iron when bioavailable. Since the processing and formulation of food influence iron bioavailability, the present study investigated for the first time, their effects on hummus. Firstly, iron bioaccessibility was assessed on eight samples (prepared according to the screening Hadamard matrix) by in vitro digestion preceding iron dialysis. Then, iron bioavailability of four selected samples was estimated by the in vitro digestion/Caco-2 cell model. Total and dialyzable iron were determined by the atomic absorption spectrometry and ferritin formation was determined using an ELISA kit. Only autoclaving, among other processes, had a significant effect on iron bioaccessibility (+9.5, p < 0.05). Lemon juice had the highest positive effect (+15.9, p < 0.05). Consequently, the effect of its acidic components were investigated based on a full factorial 2³ experimental design; no significant difference was detected. Garlic’s effect was not significant, but tahini’s effect was negative (−8.9, p < 0.05). Despite the latter, hummus had a higher iron bioavailability than only cooked chickpeas (30.4 and 7.23 ng ferritin/mg protein, respectively). In conclusion, hummus may be a promising source of iron; further in vivo studies are needed for confirmation. Full article

Siderophores are iron chelators with low molecular weight secreted by microorganisms. Siderophores have the potential to become natural iron fortifiers. To explore the feasibility of the application of Synechococcus sp. PCC7002-derived siderophores as iron fortifiers, Synechococcus sp. PCC7002, as a carrier, was fermented to produce siderophores. The absorption mechanism and anemia intervention effect of siderophores-chelated iron (SCI) were studied through the polarized Caco-2 Cell monolayers and the rat model of iron-deficiency anemia, respectively. The results indicated that siderophores (from Synechococcus sp. PCC7002) had an enhancing effect on iron absorption in polarized Caco-2 cell monolayers. The main absorption site of SCI was duodenum with pH 5.5, and the absorption methods included endocytosis and DMT1, with endocytosis being dominant. The effect of sodium phytate on SCI was less than that of ferrous sulfate. Therefore, SCI could resist inhibitory iron absorption factors in polarized Caco-2 cell monolayers. SCI showed significantly higher relative bioavailability (133.58 ± 15.42%) than ferrous sulfate (100 ± 14.84%) and ferric citrate (66.34 ± 8.715%) in the rat model. Food intake, hemoglobin concentration, and hematocrit and serum iron concentration of rats improved significantly after Fe-repletion. Overall, this study indicated that siderophores derived from Synechococcus sp. PCC7002 could be an effective and feasible iron nutritive fortifier. Full article

Chronic renal failure involving hemodialysis results in blood loss during filtration. Iron deficiency and iron deficiency anemia can result. A compensatory increase in iron dosage has many side effects including discomfort. Elemental iron is a highly-pure iron source, which reduces the frequency of dosages; the solubility decreases with increased particle size or pore size. In this study, synthesized mesoporous iron particles (MIPs) were used to relieve iron deficiency anemia. Their bioavailability was measured in vitro by a Caco-2 cell model and in vivo in iron-deficient rats. In vitro bioavailability of MIPs was examined by measuring ferritin content in the Caco-2 cell model. Iron uptake of MIPs was significantly higher than commercial iron particles, which were less porous. In vivo bioavailability of MIPs was examined by measuring body weight gain and red blood cell-related parameters, compared with the bioavailability of standard drug ferrous sulfate in iron-deficient anemic rats. Finally, average hemoglobin content and hemoglobin regeneration efficiency were significantly higher in anemic rats supplemented with commercial iron particles, compared to anemic controls. In the 28-day oral toxicity test, MIPs were not significantly toxic to rat physiology or tissue histopathology. Thus, MIPs may allow effective recovery of hemoglobin in iron deficiency anemia. Full article

Superparamagnetic iron oxide nanoparticles are one of the most prominent agents used in theranostic applications, with MRI imaging the main application assessed. The biomolecular interface formed on the surface of a nanoparticle in a biological medium determines its behaviour in vitro and in vivo. In this study, we have compared the formation of the protein corona on highly monodisperse iron oxide nanoparticles with two different coatings, dimercaptosuccinic acid (DMSA), and after conjugation, with a bifunctional polyethylene glycol (PEG)-derived molecule (2000 Da) in the presence of Wistar rat plasma. The protein fingerprints around the nanoparticles were analysed in an extensive proteomic study. The results presented in this work indicate that the composition of the protein corona is very difficult to predict. Proteins from different functional categories—cell components, lipoproteins, complement, coagulation, immunoglobulins, enzymes and transport proteins—were identified in all samples with very small variability. Although both types of nanoparticles have similar amounts of bonded proteins, very slight differences in the composition of the corona might explain the variation observed in the uptake and biotransformation of these nanoparticles in Caco-2 and RAW 264.7 cells. Cytotoxicity was also studied using a standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Controlling nanoparticles’ reactivity to the biological environment by deciding on its surface functionalization may suggest new routes in the control of the biodistribution, biodegradation and clearance of multifunctional nanomedicines. Full article

Nicotianamine (NA) is a low-molecular weight metal chelator in plants with high affinity for ferrous iron (Fe²⁺) and other divalent metal cations. In graminaceous plant species, NA serves as the biosynthetic precursor to 2′ deoxymugineic acid (DMA), a root-secreted mugineic acid family phytosiderophore that chelates ferric iron (Fe³⁺) in the rhizosphere for subsequent uptake by the plant. Previous studies have flagged NA and/or DMA as enhancers of Fe bioavailability in cereal grain although the extent of this promotion has not been quantified. In this study, we utilized the Caco-2 cell system to compare NA and DMA to two known enhancers of Fe bioavailability—epicatechin (Epi) and ascorbic acid (AsA)—and found that both NA and DMA are stronger enhancers of Fe bioavailability than Epi, and NA is a stronger enhancer of Fe bioavailability than AsA. Furthermore, NA reversed Fe uptake inhibition by Myricetin (Myr) more than Epi, highlighting NA as an important target for biofortification strategies aimed at improving Fe bioavailability in staple plant foods. Full article

Background: Iron deficiency is a public health problem in many low- and middle-income countries. Introduction of agro-industrial food by-products, as additional source of nutrients, could help alleviate this micronutrient deficiency, provide alternative sources of nutrients and calories in developed countries, and be a partial solution for disposal of agro-industry by-products. Methods: The aim of this study was to determine iron bioavailability of 5 by-products from Brazilian agro-industry (peels from cucumber, pumpkin, and jackfruit, cupuaçu seed peel, and rice bran), using the in vitro digestion/ Caco-2 cell model; with Caco-2 cell ferritin formation as a surrogate marker of iron bioavailability. Total and dialyzable Fe, macronutrients, the concentrations of iron-uptake inhibitors (phytic acid, tannins, fiber) and their correlation with iron bioavailability were also evaluated. Results: The iron content of all by-products was high, but the concentration of iron and predicted bioavailability were not related. Rice bran and cupuaçu seed peel had the highest amount of phytic acid and tannins, and lowest iron bioavailability. Cucumber peels alone, and with added extrinsic Fe, and pumpkin peels with extrinsic added iron, had the highest iron bioavailability. Conclusion: The results suggest that cucumber and pumpkin peel could be valuable alternative sources of bioavailable Fe to reduce iron deficiency in at-risk populations. Full article

Iron deficiency is a major public health concern and nutritional approaches are required to reduce its prevalence. The aim of this study was to examine the iron bioavailability of a novel home fortificant, the “Lucky Iron Fish™” (LIF) (www.luckyironfish.com/shop, Guelph, Canada) and the impact of dietary factors and a food matrix on iron uptake from LIF in Caco-2 cells. LIF released a substantial quantity of iron (about 1.2 mM) at pH 2 but this iron was only slightly soluble at pH 7 and not taken up by cells. The addition of ascorbic acid (AA) maintained the solubility of iron released from LIF (LIF-iron) at pH 7 and facilitated iron uptake by the cells in a concentration-dependent manner. In vitro digestion of LIF-iron in the presence of peas increased iron uptake 10-fold. However, the addition of tannic acid to the digestion reduced the cellular iron uptake 7.5-fold. Additionally, LIF-iron induced an overproduction of reactive oxygen species (ROS), similar to ferrous sulfate, but this effect was counteracted by the addition of AA. Overall, our data illustrate the major influence of dietary factors on iron solubility and bioavailability from LIF, and demonstrate that the addition of AA enhances iron uptake and reduces ROS in the intestinal lumen. Full article