Bioavailability study of dried microencapsulated ferrous sulfate — SFE 171 — by means of the prophylactic-preventive method

Microencapsulated ferrous sulfate with soy lecithin (SFE-171) has been used as an iron source for the fortification of milk and dairy products. With the purpose to extend the use of this agent to other kind of foods or even to pharmaceutical preparations for oral administration, the SFE-171 was turned into a fluid powder (SFE-171-P) by means of vacuum drying. The iron bioavailability (BioFe) of SFE-171-P was evaluated in this work by means of the prophylactic-preventive method in rats, using ferrous sulfate as reference standard. Both iron sources were separately added to a basal diet of low iron content in a concentration of 10 mg iron/kg diet. Two groups of 10 weaned rats 25 days old received the fortified diets during 28 days, while a third group of the same size received the basal diet without iron additions. The weights and haemoglobin concentrations (HbC) of every animal were determined before and after the treatment, thus allowing the calculation of the mass of iron incorporated into haemoglobin (HbFe) during this period. The BioFe of the iron sources were obtained as the percentage ratio between the HbFe and the mass of iron consumed by each animal. The results were also given as Relative Biological Value (RBV), which relates the BioFe of the studied source with that of the reference standard. The liver iron concentration (LIC) of each animal was determined at the end of the experiment in order to evaluate the influence of the studied iron sources on the liver iron stores. SFE-171-P presented BioFe, RBV and LIC values of (47 ± 7) %, 109% and (46.6 ± 3.4) mg/kg respectively, while the corresponding values for the reference standard were of (43 ± 7)%, 100% and (45.0 ± 4.7) mg/kg. These results show that the drying process used to produce the SFE-171-P does not affect its bioavailability, which is also adequate for the potential use of this product in food fortification or with pharmaceutical purposes.     

Bioavailability of Stabilised Ferrous Gluconate with Glycine in Fresh Cheese Matrix: a Novel Iron Compound for Food Fortification

Iron fortification of foods continues to be one of the preferred ways of improving the iron status of the population. Dairy product is a common product in the diet; therefore, it is a plausible vehicle for iron fortification. This study aims to investigate the bioavailability of ferrous gluconate stabilised with glycine (FGSG) in a fresh cheese fortified with zinc. The iron bioavailability of fresh cheese fortified with either FGSG and with or without zinc and FGSG in aqueous solution and a water solution of ferrous ascorbate (reference dose) was studied using double radio iron (⁵⁵Fe and ⁵⁹Fe) erythrocyte incorporation in 15 male subjects. All subjects presented with normal values for iron status parameters. The geometric mean of iron bioavailability for the water solution of FGSG was 38.2 %, adjusted to 40 % from reference doses (N.S.). Iron bioavailability in fresh cheese fortified with Ca and Zn was 15.4 % and was 23.1 % without Zn, adjusted to 40 % from reference doses (N.S.). The results of the present study show that the novel iron compound ferrous gluconate stabilised with glycine in a fresh cheese matrix is a good source of iron and can be used in iron fortification programmes.     

Iron bioavailability from fortified fluid milk and petit suisse cheese determined by the prophylactic-preventive method

In this research, we measure the iron bioavailability of micronized ferric orthophosphate when it is used to fortify low-fat fluid milk enriched with calcium and petit suisse cheese using the prophylactic-preventive method in rats. Four groups of male weaned rats received a basal diet (control diet; 6.5 ppm Fe), a reference standard diet (SO₄Fe; 18.2 ppm Fe), a basal diet using iron-fortified fluid milk as the iron source (milk diet; Fe ppm 17.9), and a basal diet using iron-fortified petit suisse cheese as the iron source (cheese diet; 18.0 ppm Fe) for 22 d. The iron bioavailability of the different sources was calculated as the ratio between the mass of iron incorporated into hemoglobin during the experiment and the total iron intake per animal. The relative biological values with regard to the reference standard (RBV%) were 61% and 69% for the milk and cheese diet, respectively. These results show that according to this method, the iron bioavailability in both fortified foods can be considered as medium bioavailability rates.     

Hair Trace Element Levels in Han and Indigenous Hualien Inhabitants in Taiwan

The boron content was determined in 42 different foods consumed in Istanbul, Turkey. Eleven species of fruit, ten species of vegetable, eight species of food of animal origin, four species of grain, two species of nuts, two species of legume, and five other kinds of foods were included to this study. They were analyzed by two methods: Inductively coupled plasma mass spectrometry (ICP-MS) technique and carminic acid assay, and the results of two methods were also compared. Boron concentration in foods ranged between 0.06–37.2 mg/kg. Nuts had the highest boron content while foods of animal origin had the lowest. A strong correlation was found between the results of the carminic acid assay and the ICP-MS technique (p = 0.0001, Pearson correlation coefficient: r = 0.956). Bland Altman analysis also supported this correlation. ICP-MS is one of the most common, reliable, and powerful method for boron determination. The results of our study show that spectrophotometric carminic acid assay can provide similar results to ICP-MS, and the boron content in food materials can be also determined by spectrophotometric method.

     

Bioavailability studies of a new iron source by means of the prophylactic-preventive method in rats

The bioavailability of iron from a new commercial source containing ferric gluconate stabilized with glycine sold under the trade name Bioferrico™ was studied in this work by means of the prophylactic-preventive test in rats. NaFeEDTA was also studied by the same methodology for comparative purposes and ferrous sulfate was used as the reference standard. The test was conducted for 4 wk with male weaned rats, which were randomized into four groups of at least eight animals each. A control group received a basal diet of low-iron content, whereas the other groups received the same diet with iron added at a dose of 20 mg/kg as FeSO₄·7H₂O, NaFeEDTA, and Bioferrico, respectively. Individual hemoglobin concentrations (HbC) and weights were determined at the beginning and at the end of the study and food intake was daily registered. The iron bioavailability (BioFe) of each source was calculated as the ratio between the amount of iron incorporated into hemoglobin during the treatment (HbFe) and the total iron intake per animal (ToFeIn). A relative biological value (RBV) was obtained for each iron source under study as the ratio between the BioFe of the tested compound and that of the reference standard. The RBVs were 98% and 86% for Bioferrico and NaFeEDTA, respectively. Bioferrico showed a high bioavailability and behaved inertly in relation to the sensorial properties of the fortified food when it was added to flour. These qualities emphasize Bioferrico as a promising source for iron fortification.     

Iron bioavailability from fortified petit suisse cheese determined by the prophylactic-preventive method

In this research, we measured the iron bioavailability of ferrous gluconate stabilized with glycine (SFG) when it is used to fortify petit suisse cheese using the prophylactic-preventive method in rats. Three groups of male, weaned rats received a basal diet (control diet; 5.2 ppm Fe), a reference standard diet (SO₄Fe; 9.2 ppm Fe), and a basal diet using iron-fortified petit suisse cheese as the iron source (cheese diet; 8.8 ppm Fe) for 22d. The iron bioavailability was calculated as the ratio between the mass of iron incorporated into hemoglobin and the total iron intake per animal during the treatment. These values (BioFe) were 68% and 72% for SFG and ferrous sulfate, respectively. The value of the Relative Biological Value (RBV) was 95% for SFG in petit suisse cheese. These results show that according to this method, the iron bioavailability from industrial fortified petit suisse cheese can be considered as a high bioavailability rate.     

Biochemical properties of canine serum ferritin: iron content and nonbinding to concanavalin A

A sandwich enzyme-linked immunosorbent assay using H-subunit-rich canine heart ferritin as a standard has been developed for measuring canine serum ferritin which is H-subunit-rich. Serum ferritin concentrations in 51 normal dogs ranged from 143 to 1766 ng ml^–1, with a mean value of 479±286 (SD) ng ml^–1. Serum ferritin iron concentrations as determined by an immunoprecipitation technique ranged from 30.4 to 115.9 ng ml^–1 in 15 normal dogs with serum ferritin protein levels of 298 to 959 ng ml^–1. There was a significant linear correlation between the serum ferritin iron and protein levels (r=0.9441, P<0.001), and the mean iron/protein ratio of serum ferritin was 0.112±0.017. When canine sera were incubated with concanavalin A-Sepharose 4B, we observed the apparent binding of serum ferritin to concanavalin A. However, ferritin obtained by heat-treating the sera at pH 4.8 to remove the ferritin-binding proteins did not bind to the lectin. These results suggest that canine serum ferritin contains a considerable amount of iron but no concanavalin A-binding G subunit present in human serum ferritin.     

A comparison of ferric-chelate reductase and chlorophyll and growth ratios as indices of selection of quince,pear and olive genotypes under iron deficiency stress

Quince (Cydonia oblonga Mill.), pear (Pyrus communis L.) and olive (Olea europaea L.) genotypes were evaluated for their tolerance to iron deficiency stress by growing young plants in three types of aerated nutrient solutions: (1) with iron, (2) without iron or (3) low in iron and with 10 mM bicarbonate. Plants were obtained either from rooted softwood cuttings or from germination of seeds. The degree of tolerance was evaluated with several indices: (1) the chlorophyll content, (2) the root Fe³⁺ reducing capacity and (3) the whole plant relative growth. Fifteen hours before Fe³⁺ reducing capacity determination, iron was applied to the roots of plants with iron-stress, since this method resulted in increasing the reductase activity. All quince and pear genotypes increased the root Fe³⁺ reducing capacity when grown in the treatments for iron-stress, in relation to control plants of the same genotypes. In olive cultivars, the Fe³⁺ reducing capacity was lower in the iron-stress treatments than in the control one. Studying the relationship between relative growth and chlorophyll content for each genotype under iron-stress, in relation to both indices in control plants, a classification of species and genotypes was established. According to that, most olive cultivars and some pear rootstocks and cultivars appear more iron-efficient than quince rootstocks. Our study shows that in some woody species, determining root Fe³⁺ reducing capacity is not the best method to establish tolerance to iron deficiency stress.     

Iron and cadmium uptake by duodenum of hypotransferrinaemic mice

Absorption from food is an important route for entry of the toxic metal, cadmium, into the body. Both cadmium and iron are believed to be taken up by duodenal enterocytes via the iron regulated, proton-coupled transporter, DMT1. This means that cadmium uptake could be enhanced in conditions where iron absorption is increased. We measured pH dependent uptake of ¹⁰⁹Cd and ⁵⁹Fe by duodenum from mice with an in vitro method. Mice with experimental (hypoxia, iron deficiency) or hereditary (hypotransferrinaemia) increased iron absorption were studied. All three groups of mice showed increased ⁵⁹Fe uptake (p<0.05) compared to their respective controls. Hypotransferrinaemic and iron deficient mice exhibited an increase in ¹⁰⁹Cd uptake (p<0.05). Cadmium uptake was not, however, increased by lowering the medium pH from 7.4 to 6. In contrast, ⁵⁹Fe uptake (from ⁵⁹FeNTA₂) and ferric reductase activity was increased by lowering medium pH in control and iron deficient mice (p<0.05). The data show that duodenal cadmium uptake can be increased by hereditary iron overload conditions. The uptake is not, however, altered by lowering medium pH suggesting that DMT1-independent uptake pathways may operate.     

The determination of ferric iron in plants by HPLC using the microbial iron chelator desferrioxamine E

Common methods for plant iron determination are based on atomic absorption spectroscopy, radioactive measurements or extraction with subsequent spectrophotometry. However, accuracy is often a problem due to background, contamination and interfering compounds. We here describe a novel method for the easy determination of ferric iron in plants by chelation with a highly effective microbial siderophore and separation by high performance liquid chromatography (HPLC). After addition of colourless desferrioxamine E (DFE) to plant fluids, the soluble iron is trapped as a brown-red ferrioxamine E (FoxE) complex which is subsequently separated by HPLC on a reversed phase column. The formed FoxE complex can be identified due to its ligand-to-metal charge transfer band at 435 nm. Alternatively, elution of both, DFE and FoxE can be followed as separate peaks at 220 nm wavelength with characteristic retention times. The extraordinarily high stability constant of DFE with ferric iron of K=10³² enables extraction of iron from a variety of ferrous and ferric iron compounds and allows quantitation after separation by HPLC without interference by coloured by-products. Thus, iron bound to protein, amino acids, citrate and other organic acid ligands and even insoluble ferric hydroxides and phosphates can be solubilized in the presence desferrioxamine E. The “Ferrioxamine E method” can be applied to all kinds of plant fluids (apoplasmic, xylem, phloem, intracellular) either at physiological pH or even at acid pH values. The FoxE complex is stable down to pH 1 allowing protein removal by perchloric acid treatment and HPLC separation in the presence of trifluoroacetic acid containing eluents. Published online December 2004     

Development and evaluation of multiplex PCR for detection of T-2 and zearalenone producing Fusarium spp

The study aimed to develop and evaluate a multiplex polymerase chain reaction assay (mPCR) for the concurrent detection of three major mycotoxin metabolic pathway genes, namely tri8 (T-2 toxin), tri6 (trichothecene) and pks4 (zearalenone), along with competitive internal amplification control. Specific primers for each of the aforementioned genes were optimized and validated using 14 reference strains and 10 pure culture isolates. The optimized mPCR assay detected the three metabolic pathway genes in artificially contaminated maize samples with a sensitivity of 2 × 10³ CFU per g for tri6 and pks4 positive Fusarium strains, whereas 2 × 10⁴ CFU per g for tri8 positive Fusarium strains. Application of the developed mPCR assay to 30 cereal and 20 feed samples revealed 24% (12 of 50) contamination with either one or more mycotoxins. The results of mPCR assay were further evaluated with high performance liquid chromatography (HPLC), and both methods provided unequivocal results. This mPCR assay might be a supplementary tool to conventional mycotoxin analytical techniques like thin-layer chromatography, HPLC, etc. The current mPCR assay is a rapid and reliable tool for simultaneous, sensitive and specific detection of T-2, zearalenone and trichothecene producing Fusarium spp. from naturally contaminated foods and to monitor them during the processing steps of food and feed commodities.     

Nutritional and technological behavior of stabilized iron-gluconate in wheat flour

Food fortification has been shown to be an effective strategy to overcome iron malnutrition. When a new iron compound is developed for this purpose, it must be evaluated from a nutritional and technological point of view before adding it into foods. In this way, we have evaluated ferrous gluconate stabilized by glycine as a new iron source to be used in wheat flour fortification. We performed biological studies in rats as well as sensory perceptions by human subjects in wheat flour fortified with this iron source. The productions of pentane as a rancidity indicator as well as the change of the sensorial properties of the biscuits made with stabilized ferrous gluconate-fortified wheat flour were negligible. Iron absorption in water from this iron source was similar to the reference standard ferrous sulfate. Nevertheless, because of the phytic acid content, iron absorption from fortified wheat flour decrease 40% for both iron sources. The addition of zinc from different sources did not modify iron absorption from ferrous sulfate and stabilized ferrous gluconate in water and wheat flour. The iron absorption mechanism as well as the biodistribution studies demonstrate that the biological behavior of this iron source does not differ significantly from the reference standard. These results demonstrate that the iron source under study has adequate properties to be used in wheat flour fortification. Nevertheless, more research is needed before considering this iron source for its massive use in food fortification.     

Determination of lincomycin residues in salmon tissues by gas chromatography with nitrogen-phosphorus detection

A sensitive method for the determination of lincomycin residues in fish tissues is described. Lincomycin was extracted from fish tissues with phosphate buffer (pH 4.5). The extract was concentrated with a C₁₈ solid-phase extraction cartridge and further cleaned up by solvent extraction. Lincomycin was derivatized with N,O-bis(trimethylsilyl)trifluoroacetamide to form a trimethylsilyl derivative before being analyzed by gas chromatography with nitrogen-phosphorus detection. Coumaphos was used as the internal standard. Assays showed good linearity in the range 25–250 ppb (ng/g) (r = 0.9994). Recoveries of fortified lincomycin at 50, 100 and 200 ppb were>80% with relative standard deviation <6%. The limit of detection of the method was 1.7 ppb and the limit of quantitation was 3.8 ppb.     

Iron deficiency in obese postmenopausal women

Objective: This study evaluates whether the iron deficiency suggested in children and adolescents with overweight is also present with increasing age. Research Methods and Procedures: We examined 50 consecutive postmenopausal nondiabetic white women with a BMI ≥30 kg/m² and 50 non‐obese seemingly healthy women as a control group. In addition to the traditional indices of iron status, we measured the soluble transferrin receptor (sTfR) levels, a sensitive and highly quantitative indicator of early iron deficiency not influenced by the acute phase response. Results: Obese women have higher serum sTfR levels than control subjects [1.38 (range, 0.89 to 2.39) vs. 1.16 mg/dL (range, 0.69 to 2.03 mg/dL); p < 0.001]. However, no difference in ferritin concentration was observed between the groups [70.50 (range, 18 to 219) vs. 69.50 ng/mL (range, 24 to 270 ng/mL); p = not significant]. A positive correlation between BMI and sTfR concentration was detected. On multiple regression analyses, BMI (positively) and ferritin (inversely) were independent predictors accounting for sTfR. Discussion: These results suggest that a moderate degree of iron deficiency is also present among adult women with obesity. The determination of sTfR is useful in the evaluation of iron status in this condition. Further studies with a greater number of patients are required to investigate the relationship between tissue iron concentrations and obesity.     

Enantioseparation and determination of flumequine enantiomers in multiple food matrices with chiral liquid chromatography coupled with tandem mass spectrometry

The present work firstly described the enantioseparation and determination of flumequine enantiomers in milk, yogurt, chicken, beef, egg, and honey samples by chiral liquid chromatography‐tandem mass spectrometry. The enantioseparation was performed under reversed‐phase conditions on a Chiralpak IC column at 20°C. The effects of chiral stationary phase, mobile phase components, and column temperature on the separation of flumequine enantiomers have been studied in detail. Target compounds were extracted from six different matrices with individual extraction procedure followed by cleanup using Cleanert C18 solid phase extraction cartridge. Good linearity (R²>0.9913) was obtained over the concentration range of 0.125 to 12.5 ng g^‐1 for each enantiomer in matrix‐matched standard calibration curves. The limits of detection and limits of quantification of two flumequine enantiomers were 0.015‐0.024 and 0.045‐0.063 ng g^‐1, respectively. The average recoveries of the targeted compounds varied from 82.3 to 110.5%, with relative standard deviation less than 11.7%. The method was successfully applied to the determination of flumequine enantiomers in multiple food matrices, providing a reliable method for evaluating the potential risk in animal productions.     

Determination of the R2* relaxation rate constant for estimating hepatic iron concentration: A customized approach that considers liver fat infiltration

PurposeΑ customized approach to determine R₂* relaxation rate for hepatic iron concentration (HIC) estimation is presented, and is evaluated in the context of concurrent liver fat infiltration.MethodsThe proposed method employs a customized acquisition protocol, featuring a 16-echo, gradient-echo sequence, and a bi-exponential least squares fitting that considers baseline noise and uses a cosine function to correct for fat-induced signal oscillation. 193 patients with wide-ranging HIC and liver fat fraction (FF) were imaged at 1.5 T. In severely iron-overload patients, a four-echo train technique was applied to enforce all 16 echoes in the 1.2–4.0 ms range. Acquired data were compared to corresponding results obtained with the IDEAL IQ method.ResultsTechniques employed to counter the rapid signal decay in iron-overloaded liver, such as the offset and the truncation methods, have to be combined with the appropriate calibration curve to provide reliable HIC estimation. When high grade steatosis and siderosis co-exist, fat-suppression may downgrade siderosis. A high correlation was observed between data obtained with the proposed technique and the IDEAL IQ method, except from the high R₂* region. However, systematic differences were detected. In the concurrent presence of high FF and non-severe iron overload, it is postulated that the bi-exponential model may attribute patient siderosis grading more accurately than IDEAL IQ, while simultaneously providing reliable FF estimation.ConclusionsThe proposed approach is widely available and seems capable of providing reliable R₂* measurements regardless of liver steatosis grading, whilst it succeeds in averting significant R₂* underestimation in severely iron-overloaded liver.     

Determination of naphazoline hydrochloride in biological and pharmaceutical samples by a quantum dot‐assisted chemiluminescence system using response‐surface methodology

A simple and highly sensitive chemiluminescence (CL) method is reported for the determination of naphazoline hydrochloride (NH). It was found that the weak CL from the reaction of luminol and KIO₄ in an alkaline medium could be highly amplified by cysteine‐capped cadmium telluride quantum dots (QDs) and the enhanced CL was effectively quenched by NH and this finding was utilized as a basis for the determination of NH. The QDs were synthesized in aqueous medium and characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), and UV‐vis and photoluminescence spectroscopy. A possible mechanism was proposed for the CL system based on radical identification experiments, along with CL spectrum of the system. The experimental parameters were optimized by the reliable response surface methodology (RSM). Under the optimized experimental conditions, the proposed method allowed the determination of NH over the range of 5.0 × 10^‐10–2.0 × 10^‐7 mol/L (r² = 0.9993, n = 10). The precision (RSD%) of the method, obtained from five replicate determinations of 2.0 and 150 nmol/L NH, was found to be 1.0% and 1.3%, respectively. The method was successfully applied to the determination of NH in pharmaceutical formulations and human urine and serum samples with results corroborated with the aid of those obtained from a standard method. Copyright © 2014 John Wiley & Sons, Ltd.     

Non-protein-bound iron detection in small samples of biological fluids and tissues

Interest in the pro-oxidative nature of non-protein-bound-iron (NPBI) led to the development of an assay for its detection. The aim was to set up a reliable method of detecting NPBI in small samples of biological fluids and tissue. The method was based on preferential chelation of NPBI by a large excess of the low-affinity ligand nitrilotriacetic acid. To separate NPBI, a two-step filtration procedure was used. All glassware and plasticware were treated to minimize iron contamination. Measurements were performed in plasma, amniotic fluid, bronchoalveolar lavage, and brain tissues. The analytic system detected iron as ferric nitrate standard down to a concentration of 0.01 μM. The 1,2-dimethyl-3-hydroxy-4(1H)-pyridone-Fe(DHP-Fe) complex eluted with a retention time of about 2.6 min. The standard curve for the DHP-Fe complex was linear between 0.01 and 400 μM in water as well as in plasma, bronchoalveolar lavage, brain tissue, and amniotic fluid. The detection limit was 0.01 μM for all biological fluids and brain tissue. The data show that reliable measurements of NPBI are possible in studies on oxidative stress under experimental and clinical conditions. The possibility of investigating NPBI involvement in free-radical injury might be useful in all human diseases in which oxidative stress occur.     

Determination of the water-extractable fraction of iron in selected medicinal plant raw materials: Folium Menthae,Folium Urticae and Folium Salviae

Abstract

The aim of the investigation was to study the water-extractable iron species at different pH values from selected medicinal plant materials, therefore total and water-extractable iron species were determined in 30 samples of the medicinal plants Folium Menthae, Folium Urticae and Folium Salviae. The extractions were infusions popularly used by patients. Microwave digestion of the plant samples, and flame atomic absorption spectrometry (FAAS) was used for the determination of iron. Total iron ranged from 132.93 to 149.26 mg kg^?1 of dry plant weight (d.w.) in Folium Menthae, from 47.62 to 58.09 mg kg^?1(d.w.) in Folium Urticae, and from 189.81 to 233.58 mg kg^?1 (d.w.) in Folium Salviae. The ranges of concentrations of water-extractable iron species were found to be lower than those of the total iron concentrations, viz. 9.45, 5.38 and 9.04 mg kg^?1 of d.w. in Folium Menthae, Folium Urticae and Folium Salviae, respectively. Taking into consideration the potential bioavailability of iron species in solutions of different pH values representing the acidity of particular segments of the digestive system of humans, these fractions of iron are very low in comparison with the total iron contents, especially the species detected at pH = 1.2. Based on the comparison with the values of Recommended Daily Allowances (RDA) for women and men, the water-extractable fractions of iron found in the studied plant materials, cannot be significant sources of that microelement for patients.     

High-resolution liquid chromatographic method using ultraviolet detection for determination of ondansetron in human plasma

This paper describes a simple technique for extraction and a sensitive high-performance liquid chromatographic method for separation and quantitation of ondansetron in human plasma. The procedure involved liquid–liquid extraction of ondansetron from plasma, reversed-phase HPLC separation and ultraviolet detection at 305 nm. The internal standard method was applied for quantitation. The recovery of ondansetron was >85%. Linearity was good throughout the concentration range anticipated in human plasma from investigations in panic disorder (0.5–15 ng/ml, r² ranging from 0.9953 to 0.9988). This method was applied to the determination of plasma concentrations of ondansetron in humans.