Iron bis-glycine chelate competes for the nonheme-iron absorption pathway

Antarctic Krill Derived Nonapeptide as an Effective Iron-Binding Ligand for Facilitating Iron Absorption via the Small Intestine

A novel nonapeptide DTDSEEEIR identified from Antarctic krill (Euphausia superba) iron-binding peptides was used in this study to analyze its iron-binding sites and structural changes after iron coordination. The enzymatic resistance and transport of DTDSEEEIR-iron during gastrointestinal digestion and absorption as well as the relationship between the DTDSEEEIR stability and the enhancement of iron absorption were further explored. Results revealed that iron ions spontaneously bound to the carboxyl, hydroxyl, and amino groups of the DTDSEEEIR peptide, which induced the folding of DTDSEEEIR to form a more orderly structure. The DTDSEEEIR peptide remained stable to a certain extent (79.60 ± 0.19%) after gastrointestinal digestion and the coordination of iron improved the digestive stability of the DTDSEEEIR peptide (93.89 ± 1.37%). Moreover, the stability of DTDSEEEIR across intestinal epithelium had a positive effect on iron absorption, which implied that DTDSEEEIR might carry iron ions through intestinal epithelial cells.

Identification of multiple dysregulated metabolic pathways by GC-MS-based profiling of liver tissue in mice with OVA-induced asthma exposed to PM2.5

Particulate matter (PM) exposure increases the risk of asthma. However, the effect of PM_2.5 exposure on liver metabolism in mice with asthma symptoms remains unclear. We established an ovalbumin (OVA)-induced asthma model in mice and divided the animals into four groups: control group (C), PM_2.5 exposure group (P), OVA-induced asthma group (O) and OVA-induced asthma PM_2.5 exposure group (OP). Gas chromatography-mass spectrometry (GC-MS) was used to identify the metabolite markers and related perturbed metabolic pathways in mouse liver tissue after PM_2.5 exposure. Multivariate analysis showed 9 and 12 potential metabolite markers in the P and OP groups, respectively, after PM_2.5 exposure that were significantly correlated with lipid peroxidation indices. PM_2.5 exposure perturbed 5 and 7 metabolic pathways in the P and OP groups, respectively. These metabolic pathways mainly involve the lipid metabolism, amino acid metabolism, carbohydrate metabolism, and nucleotide metabolism. These results highlight the potential to study PM_2.5-triggered alterations via liver tissue in normal and OVA-induced asthmatic mice to gain a more realistic appraisal of the resulting early toxicity events. Additionally, these results revealed potential metabolite markers of early antioxidant defense events triggered by PM_2.5 and indicated that metabolite markers are more sensitive than antioxidant indicators.

Protein Hydrolysates as Promoters of Non-Haem Iron Absorption

Iron (Fe) is an essential micronutrient for human growth and health. Organic iron is an excellent iron supplement due to its bioavailability. Both amino acids and peptides improve iron bioavailability and absorption and are therefore valuable components of iron supplements. This review focuses on protein hydrolysates as potential promoters of iron absorption. The ability of protein hydrolysates to chelate iron is thought to be a key attribute for the promotion of iron absorption. Iron-chelatable protein hydrolysates are categorized by their absorption forms: amino acids, di- and tri-peptides and polypeptides. Their structural characteristics, including their size and amino acid sequence, as well as the presence of special amino acids, influence their iron chelation abilities and bioavailabilities. Protein hydrolysates promote iron absorption by keeping iron soluble, reducing ferric iron to ferrous iron, and promoting transport across cell membranes into the gut. We also discuss the use and relative merits of protein hydrolysates as iron supplements.

Ferrus calcium citrate is absorbed better than iron bisglycinate in patients with Crohn's disease, but not in healthy controls

Our purpose was to compare the absorption of iron bisglycinate and ferrous calcium citrate in volunteers using an oral iron tolerance test. Twenty volunteers, 10 healthy controls and 10 with stable Crohn's disease, agreed to participate in the study. All were given 50 mg of elemental iron as iron bisglycinate or ferrous calcium citrate. Serum iron levels were monitored for 4 hr. After a week, each received the other regimen. Using the area under the curve as indicator, the oral iron absorption test revealed that absorption of iron post-ingestion of ferrous calcium citrate was better than after ingestion of iron bisglycinate for the group as a whole (P < 0.03). Volunteers with Crohn's disease absorbed ferrous calcium citrate better than iron bisglycinate (P=0.005). No difference was noted in the absorption of either preparation by healthy volunteers. Ferrus calcium citrate is apparently more effective than iron bisglycinate in patients with Crohn's disease.