Preliminary Studies on Biodegradable Zinc Oxide Nanoparticles Doped with Fe as a Potential Form of Iron Delivery to the Living Organism

Iron is the crucial element for living organisms and its deficiency is described as the most common nutritional disorder all over the world. Nowadays, more effective and safe iron supplementation strategies for both humans and animals become one of the most important challenges in the therapy of nutritional deficiencies. Our previous in vivo studies confirmed safety and biodegradability of in-house manufactured zinc oxide-based nanoparticles and their rapid distribution to majority of organs and tissues in the body. In vitro examinations performed on Caco-2 cell line, a model of epithelial cells of the gastrointestinal tract, revealed a low toxicity of studied nanomaterials. In the current study, we investigated biodegradable zinc oxide nanoparticles doped with Fe(III) as a perspective supplementation strategy for iron deficiency. Biodegradable ZnO:Fe nanoparticles were intra-gastrically administered to adult mice and following 24 h, animals were sacrificed with collection of internal organs for further analyses. The iron concentration measured with atomic absorption spectrometry and histological staining (Perl's method) showed a rapid distribution of iron-doped nanoparticles to tissues specifically related with iron homeostasis. Accumulation of iron was also visible within hepatocytes and around blood vessels within the spleen, which might indicate the transfer of Fe-doped nanoparticles from the bloodstream into the tissue. Reassuming, preliminary results obtained in the current study suggest that biodegradable ZnO nanoparticles doped with Fe might be a good carriers of exogenous iron in the living body. Therefore, subsequent investigations focus on determination an exact mechanisms related with an iron deposition in the tissue and influence of nanoparticle carriers on iron metabolism are required.

Benefits and risks of iron supplementation in anemic neonatal pigs

Iron deficiency is a common health problem. The most severe consequence of this disorder is iron deficiency anemia (IDA), which is considered the most common nutritional deficiency worldwide. Newborn piglets are an ideal model to explore the multifaceted etiology of IDA in mammals, as IDA is the most prevalent deficiency disorder throughout the early postnatal period in this species and frequently develops into a critical illness. Here, we report the very low expression of duodenal iron transporters in pigs during the first days of life. We postulate that this low expression level is why the iron demands of the piglet body are not met by iron absorption during this period. Interestingly, we found that a low level of duodenal divalent metal transporter 1 and ferroportin, two iron transporters located on the apical and basolateral membrane of duodenal absorptive enterocytes, respectively, correlates with abnormally high expression of hepcidin, despite the poor hepatic and overall iron status of these animals. Parenteral iron supplementation by a unique intramuscular administration of large amounts of iron dextran is current practice for the treatment of IDA in piglets. However, the potential toxicity of such supplemental iron implies the necessity for caution when applying this treatment. Here we demonstrate that a modified strategy for iron supplementation of newborn piglets with iron dextran improves the piglets' hematological status, attenuates the induction of hepcidin expression, and minimizes the toxicity of the administered iron.

Quantitative study of soybean-induced changes in proliferation and programmed cell death in the intestinal mucosa of young rats

The use of soybean in human and animal nutrition is limited because of high content of bioactive compounds: enzyme inhibitors, polyphenols, goitrogens, phytates, saponins, sugars, and agglutinins. The damage of intestinal mucosa structure was previously observed in animals fed soybean supplemented diets. Hence, the objectives of the presented study were to compare intensity of epithelium remodeling processes in different intestinal segments, and to evaluate the influence of the 1% of soybean dietary supplementation on the processes in intestinal mucosa. The experiment was performed on 30 Wistar rats fed AIN-93 based diets. Animals were divided randomly into three groups: control (CTRL), with 1% of raw soybean (RS) and with 1% of soaked and boiled soybean (BS). The samples of: duodenum (DUO), proximal jejunum (PROX), mid-jejunum (MID), distal-jejunum (DIST) and ileum (ILE) were collected. The following processes in these samples were evaluated: mitosis (Ki-67), apoptosis (Cpp32), autophagy (MAP I LC3) and DNA damage (p53). Present data show that modification of soybean by soaking and subsequent boiling markedly influences the enterocyte turnover in the small intestine mucosa. Increased mitotic ratio in the intestine of rats fed with boiled soybean masks the negative effects of soybean on the small intestine structure.

A characterization of the activities of iron regulatory protein 1 in various farm animal species

Iron regulatory protein 1 (IRP1) post-transcriptionally regulates the expression of proteins involved in the iron metabolism of mammals. IRP1 is a bifunctional cytosolic protein which can exhibit aconitase activity or bind to iron responsive element (IREs) in the untranslated regions of specific mRNAs. The modulation of IRP1 activities and its consequence for intracellular iron homeostasis is best characterized in rodents and humans. Little is known about IRP1 in farm animals. In this study, we analyzed the two activities of IRP1 in the livers of four farm animal species (cattle, goat, pig and rabbit) and their relationship to hepatic iron content. We found an inverse correlation between spontaneous IRP1 IRE binding activity and non-haem iron content in the liver. Using the electrophoretic mobility shift assay, we showed differential mobility of IRE/IRP1 complexes formed with hepatic cytosolic extracts from various farm animal species. We discuss this observation in relation to a comparative analysis of mammalian IRP1 amino acid sequences.

Effect of dietary protein level and source on bone mineralization in rats

Bone mineralization was studied in rats. Animals were divided into three feeding groups: LCP - diet with 13.5% crude protein in DM (5% of gluten, 10% of casein), HCP - diet with 21.2% CP in DM (8% of gluten, 10% of casein), and LSM - diet based on grain meals and meat-bone meal (21% CP in DM). After 28 days feeding, animals were euthanased by cervical dislocation and femur bones were collected, weighed and kept frozen until analyses. Diets with 21% protein (HCP, LSM) significantly increased weight of femur bones. Despite of the substantially higher ash level (7.1%) in the LSM diet than in the LCP diet (3.4%), rats of both groups had the similar bone concentration of Ca (15.7 +/- 1.1 vs. 17.4 +/- 1.1 g/kg) and Zn (178.7 +/- 7.9 vs. 173.0 +/- 8.5 mg/kg). However bone density in LSM rats was significantly higher than in LCP ones. Although rats fed HCP diet had intermediate bone density, the bone concentration of Ca (11.4 +/- 0.5 g/kg) and Zn (145.1 +/- 2.9 mg/kg) was significantly lower, than in animals fed LCP and LSM diets. This was related to the very wide protein/calcium (37:1 g/g) and protein/zinc (5.3:1 g/mg) ratios in HCP diet. Those ratios were narrowest in the LSM diet: 16.2:1 (CP/Ca) and 2.6:1 (CP/Zn). It can be conluded that protein/mineral ratio in a diet is a very important factor in bone development, besides dietary protein and ash contents itselves.

Diets containing leguminous seeds influence chromium content in the rat femur bone

Leguminous seeds contain a lot of antinutritional factors (ANFs) such as protease inhibitors, lectins and condensed tannins which can affect bioavailability of nutrients. Detrimental effect of protease inhibitors can be decreased by sulphur amino acids addition. Moreover, most of the leguminous ANFs are thermolabile. Hence, legumes tested in our study were extruded and/or diets were supplemented with methionine and cystine (0.15% + 0.15%). The present experiment was performed for 28 days on 90 Wistar rats divided into nine feeding groups. Semipurified diets (10% casein) were supplemented (10%), except the control one, with soybean (S) or faba bean (F), raw (R) or extruded (E), with addition of sulphur amino acids (SAA) or without them. The Cr concentration was determined in the femur bone. Total feed intake during whole trial widely varied among the groups and was the lowest in SR (289 g) and FR (294 g) groups. There was no correlation between feed intake and Cr content in the femur bone. Generally, 10% soybean in the diet decreased Cr concentration in the bones, and faba bean increased it. The SAA addition to diets generally increased femur Cr content. However, there was a significant interaction between SAA supplementation and extrusion of faba bean, hence, the effect of their combination was unclear.

The influence of dietary sulphur loading on metabolism and health in young sheep fed low fibre and high starch diet

The purpose of the experiment was to evaluate the long-term effect of a low roughage diet (7-8% CF) with or without sulphur (S) supplementation (elemental and sodium sulphate 1:1) on basal dietary components, Zn, Cu and S availability, rumen metabolism and health in growing sheep. The control diet contained 0.2% and the supplemented diet 0.8% of S on a DM basis. The experiment lasted 12 weeks. The intake of the diet with 0.8% of S resulted in an increase in rumen acetic acid concentration. Rumen lactic acid concentrations in S-supplemented versus control sheep were higher in the first and lower in the third month, and decreased at the end of the third month of the experiment in both groups. Blood plasma pyruvate was lower at the end of the experiment in S-supplemented sheep than in control sheep. In the 5th week of the experiment, the high S diet depressed basal nutritional components as well as Zn and Cu availability. After 12 weeks of feeding of this diet, polioencephalomalacia had developed in all sheep.

Rumen dry matter and crude protein degradability of extracted or untreated oilseeds and Leucaena leucocephala leaves

A study was undertaken to determine the rumen DM and CP degradability characteristics of soyabean, canola seed, peanut, palm kernel and Leucaena leucocephala leaves. The oilseeds were either treated with n-hexane to extract the fat or left untreated. Nylon bags were incubated in each of four rumen cannulated sheep for 0, 2, 4, 6, 12, 24 and 48 h. Animals were fed on a diet consisting of meadow hay (ad libitum) and 150 g of concentrate twice daily. Fat extraction caused a decrease (P < or = 0.05) in DM disappearance of soyabean at 0, 2, 4, 6 and 12 h and of peanuts at all incubation times. CP disappearance from peanuts was reduced (P < or = 0.05) as a result of fat extraction at 0, 2, 4, 6 and 12 h. Fat extraction of canola seed increased CP disappearance at 0, 2, 4, 6 and 24 h (P < or = 0.05). However, in the case of defatted canola seed, an increase in DM disappearance (P < or = 0.05) was observed in the first 4 incubation times and a decrease (P < or = 0.05) in the later times. Fat extraction increased (P < or = 0.05) DM disappearance of palm kernel at 0 and 48 h, but reduced it at 4, 6 and 24 h. CP disappearance of palm kernel was improved by treatment (P < or = 0.05) at 0, 4, 24 and 48 h and decreased at 12 h. In the case of palm kernel the largest differences in DM and CP disappearance occurred between the 24 and 48 h incubation times. Degradability characteristics for DM and CP of full-fat soyabean, canola seed and peanut were comparable to those of the full fat samples. Effective DM degradability of soyabean, canola seed and peanuts was 72.2 and 71.9; 74.1 and 66.8; and 85.9 and 70.8 for full fat and extracted feeds, respectively. Effective CP degradability was similar in all oilseeds with the exception of the extracted canola seed. Therefore, the incorporation of full-fat soyabean, canola seed and peanut into ruminant rations can be considered as a means of increasing the energy balance. Both palm kernel DM and CP degradabilities were characterized by slow rates of degradation by negative values "b". This suggests the predominance of microbial colonization over disappearance during incubation. DM and CP disappearance of Leucaena leucocephala leaves originating from Cuba were lower than those from Nigeria. Degradability characteristics for CP and DM of Cuban leucaena leaves showed that the linear model resulted in a better fit than the exponential one.

Comparison of the influence of dietary fibre sources with different proportions of soluble and insoluble fibre on Ca, Mg, Fe, Zn, Mn and Cu apparent absorption in rats

The 6 week experiment was performed on growing Wistar male rats. In the third and the sixth weeks digestibility trials were performed. The following high fibre preparations were supplemented to the control diet (C): high methoxylated citrus pectin (Cr); apple pomace (A), potato fiber "Povex" (P) and sugar beet pulp (B). Fibre supplementation, except Cr, significantly increased Ca, Mg, Fe, Mn, Zn, Cu excretion in faeces and decreased their apparent absorption in both trials. Significant correlations (P < or = 0.001) were found between crude, insoluble and total fibre intake and mineral excretion and apparent absorption. Apparent absorption of minerals increased from the third to the sixth week in group C and in group Cr, except Fe, while it decreased in groups P and B or showed tendency to decrease. In the sixth week the following differences (P < or = 0.05) in apparent absorption were observed between diets, in descending order: [equation: see text]

Rumen degradability of dry matter and crude fibre of irradiated and sodium hydroxide treated straws

Wheat straw (WS) and triticale straw (TS) were treated with 2- and 4%-NaOH and/or 300- and 600-kGy radiation doses (accelerated electrons) for improvement of the nutritional value of these feeds. Beside the chemical composition of straws, the nylon bag rumen disappearance of dry matter and crude fibre was estimated. NaOH did not influence the chemical composition of straws, while irradiation significantly reduced the level of crude fibre (CF), neutral detergent fibre (NDF) and acid detergent fibre (ADF) proportionally to the dose. The level of nitrogen free extractives (NFE) and alpha-linked glucose polymers pronouncedly increased in the radiated straws. NaOH treatment raised potential rumen degradability of DM and irradiation did so in the case of potential as well as effective degradability. It was not able to prove the summarized influence of both treatments on DM and CF rumen degradability of the straws. The dynamics of the rumen disappearance of DM was different in the straws.