Significance of iron bioavailability for iron recommendations

Recently, recommended dietary allowances (RDA) have been formulated by the Dutch Nutrition Council for minerals and trace elements, including iron (Fe). For some population groups in the Netherlands, it is questionable whether they easily meet the Fe recommendation. An increase in Fe intake is not always possible, but “manipulation” of Fe bioavailability ultimately may result in better Fe utilization. Various factors are known to affect Fe bioavailability. Generally, much attention is paid to diet-related factors, such as inhibitors and enhancers of Fe availability for absorption. Factors such as pH, oxidation potential, structure of food, and time of digestion often are overlooked. Of the diet-related factors, heme Fe and ascorbic acid have a strong positive effect on Fe availability for absorption, whereas oxalate and polyphenols seem to be strong inhibitors of Fe availability. Because of the many interactions that may occur simultaneously, the net effect of the various combined factors in a meal is not equal to the sum of the individual factors.     

A sulfated polyphenols-rich extract from Sabal yapa exhibits antitumor activities in Ehrlich ascites carcinoma

Cancer is the second leading cause of mortality accounting for one in every six deaths globally. Plant secondary metabolites, among them polyphenols, represent an effective and much safer alternative approach to the currently available medications. In this work, utilizing LC-MS/MS, we characterized the constituents of S. yapa leaves extract and evaluated its antioxidant and anticancer properties. In total, 34 secondary metabolites, mainly flavonoids (Tricin, luteolin, and apigenin and their glucosides as well as sulfated derivatives) were identified. The extract manifested substantial antioxidant activity in DPPH assay, and high total phenolic content determined by Folin Ciocalteu method. The extract was safe up to 4800 mg/kg b.wt. when administered orally in mice and neither affected the hematological parameters nor the liver enzyme levels at the studied dose (LD₅₀, 480 mg, kg b.wt.). In the treated animals, the extract surpassed the reference drug (5-flouro uracil) and significantly reduced the tumor volume and weight by 71.50 and 85.46%, respectively, increased the median survival time to 53.2 days and the lifespan by 116%. The extract improved all the hematological parameters, where it increased the hemoglobin (Hb) concentration, red blood cell (RBC) count, packed cell volume (PVC) and platelets by 58.21, 8.98, 9.89 and 120%, respectively, compared to the untreated EAC bearing animals. Additionally, the extract significantly declined the elevated levels of ALT and AST enzymes by 29.18% and 59.88%, respectively. In molecular docking, the annotated flavonoids displayed appreciable binding affinities to the active sites of VEGFR1 and VEGFR2. In conclusion, Saba yapa is a promising plant that can be introduced to further advanced clinical studies for the development of novel anticancer drugs with lower side effects.     

Hydrogenation as an approach to study of reactions of oxidizing polyphenols with plant proteins

Coupling of oxidation products of o-diphenols with -NH₂ groups of plant proteins can damage nutritional availability of lysine residues. Relevant model coupling products (before or after reductive acetylation or permethylation) are unstable to acid hydrolysis. Hydrogenation over Rh/Al₂O₃, at room temperature and atmospheric pressure, gave cyclohexane derivatives stable to hydrolysis and retaining, with only partial hydrogenolysis, all groups originally attached to the aromatic nucleus. Plant bulk proteins were hydrogenated with substantial conversion of their aromatic amino acids; their S-containing amino acids were desulphurized. The technique is therefore promising for study of the fate of lysine residues in “enzymically browned” proteins.     

Polyphenols,flavonoids, antioxidant activity in leaves and flowers of Tunisian Globularia alypum L. (Globulariaceae)

Leaves and flowers from Tunisian Globularia alypum were assessed for their phenolic and flavonoid contents and antioxidant activity. Phenolic (15.5–22.30 mg GAE g^?1 DW) and flavonoid (3.63–4.72 mg RE g^?1 DW) contents varied according to plant part. Globularia alypum leaves exhibited the highest phenol and flavonoid contents, and displayed the highest antioxidant activity, based on radical‐scavenging activity (295 μmol TEAC g^?1 DW) and ferric reducing power (24.27 mmol Fe2+/l). The obtained results demonstrated that some of the isolated compounds play an important role for the antioxidant activity of G. alypum and give a scientific basis to the use of this plant in traditional medicine. The methanolic extract of G. alypum could be considered as a source of potential antioxidants and will promote the reasonable usage of this plant in food technology and processing as well as for medical use.     

Optimization of enzyme-assisted improvement of polyphenols and free radical scavenging activity in red rice bran: A statistical and neural network-based approach

The current study is focused on optimizing the parameters involved in enzymatic processing of red rice bran for maximizing total polyphenol (TP) and free radical scavenging activity (FRSA). The sequential optimization strategies using central composite design (CCD) and artificial neural network (ANN) modeling linked with genetic algorithm (GA) was performed to study the effect of incubation time (60–90?min), xylanase concentration (5–10?mg/g), cellulase concentration (5–10?mg/g) on the response, i.e., total polyphenol and FRSA. The result showed that incubation time has a negative effect on the response, while the square effect of xylanase and cellulase showed positive effect on the response. A maximum TP of 2,761?mg ferulic acid Eq/100?g bran and FRSA of 778.4?mg Catechin Eq/100?g bran was achieved with incubation time (min)?=?60.491; xylanase (mg/g)?=?5.4633; cellulase (mg/g)?=?11.5825. Furthermore, ANN-GA-based optimization showed better predicting capabilities as compared to CCD.     

Effect of dietary tea polyphenols on growth performance and cell-mediated immune response of post-weaning piglets under oxidative stress

To gain insights into the effects of tea polyphenols (TP) on growth performance and cell-mediated immune response of piglets under oxidative stress, an oxidative stress model was established by intraperitoneally injecting weaned piglets with diquat. After intake of either basal diet or TP-supplemented diet for 7 d, half of the piglets in each group were challenged with diquat. Results showed that dietary TP alleviated growth depression to some extent. A T lymphocyte transformation test (LTT) demonstrated that TP promoted the proliferation and activation of T lymphocytes. The ratio of CD4+/CD8+ was elevated, indicating a recovering tendency from immune damages caused by oxidative stress. The increment of pro-inflammatory IL-1 caused by oxidative stress was attenuated, and the concentration of serum IFN-γ was decreased by TP-supplementation. However, the serum concentrations of anti-inflammatory cytokine, such as IL-4, were greatly enhanced by TP, which suggested an immune shift from Th1 to Th2. These findings supported the immunomodulatory potential of TP for piglets subjected to oxidative stress.     

Ingestion of coffee polyphenols suppresses deterioration of skin barrier function after barrier disruption,concomitant with the modulation of autonomic nervous system activity in healthy subjects

The aim of this study was to evaluate the effect of consumption of coffee polyphenols (CPPs) on the autonomic nervous system activity and decreased skin barrier function caused by sodium dodecyl sulfate (SDS) treatment. In this single-blind, placebo-controlled study, ten healthy male subjects consumed either a beverage containing CPPs or a placebo beverage for four weeks. CPPs significantly suppressed the deterioration in skin barrier function and skin moisture content induced by SDS treatment after the third week. Furthermore, in the heart rate variability analysis, CPPs significantly produced an increase in parasympathetic nervous activity, and a decrease in sympathetic nervous activity after the four weeks of beverage consumption. These results suggest that CPPs might influence the regulation of the autonomic nervous system and contribute to the suppressive effect on deterioration of skin barrier function.