Influence of vitamin D supplementation on immune function of healthy aging people:A pilot randomized controlled trial

Objectives: This study aims to investigate the influence of vitamin D supplementation on immune function of healthy older adults. Materials and methods: Designed as a randomized controlled trial, 21 participants (55–85 years) completed the study during May–November 2018 in Coventry, England. The participants were randomized into vitamin D or the control group, stratified by age, gender and body mass index. The vitamin D group (n = 12) took vitamin D3 tablets of 1,000 IU/day for 12 weeks plus vitamin D education leaflet, while the control group (n = 9) were only provided with the leaflet. At baseline, 6 and 12 weeks, plasma 25(OH)D levels and immunological and metabolic parameters including phagocytic activity of granulocytes and monocytes, tumor necrosis factor, interleukin 6, lymphocyte subsets and fasting blood glucose and lipid were measured. Dietary vitamin D intake was analyzed at baseline and week 12. Data were presented as mean ± SD. Two-way repeated measures ANOVA and independent t-test were used to analyze the data. Results: At baseline, 42.9% of the participants were vitamin D deficiency (25(OH)D 50 nmol/L. Overweight/obese participants (n = 9) had significantly lower mean plasma 25(OH)D concentration (22.3 ± 8.7 nmol/L) than normal weight participants (48.1 ± 34.3 nmol/L) (P = 0.043). There was a significant increase in plasma 25(OH)D concentration in vitamin D group compared with that in control group (P = 0.002) during the intervention period. The plasma 25(OH)D concentration in vitamin D group was increased at 6 weeks (from 38.4 ± 37.0 nmol/L at baseline to 51.0 ± 38.2 nmol/L) with little change observed between 6 and 12 weeks (51.8 ± 36.4 nmol/L). The plasma creatinine concentration in vitamin D group was significantly decreased compared with the control group (P = 0.036) (79.8 ± 7.0 μmol/L at baseline vs 75.1 ± 5.4 μmol/L at week 12). No significant effect of vitamin D supplementation was determined on immunological parameters. Conclusion: Vitamin D deficiency is common among the aging population in the UK even during the summertime. Vitamin D supplementation at 1,000 IU/day for 12 weeks significantly increased plasma 25(OH)D concentration but showed no effect on metabolic and immunological parameters except decreased plasma creatinine

Periplasmic expression of Pseudomonas fluorescens peroxidase Dyp1B and site-directed mutant Dyp1B enzymes enhances polymeric lignin degradation activity in Pseudomonas putida KT2440

Expression of lignin-oxidising Pseudomonas fluorescens Dyp1B in the periplasm of Pseudomonas putida KT2440, using a tat fusion construct, was found to lead to enhanced whole cell activity for oxidation of DCP and polymeric lignin substrates. Four amino acid residues predicted to lie at the manganese ion binding site of Pseudomonas fluorescens peroxidase Dyp1B were investigated using site-directed mutagenesis. Mutants H127R and S223A showed 2-fold and 4-fold higher kcat for Mn(II) oxidation respectively, and mutant S223A showed 2-fold enhanced production of low molecular weight phenolic products from a polymeric soda lignin. The mutant Pfl Dyp1B genes were expressed as tat fusions to investigate their effect on lignin oxidation by P. putida KT2440

Characterisation of hepcidin response to holotransferrin treatment in CHO TRVb-1 cells

Iron overload coupled with low hepcidin levels are characteristics of hereditary haemochromatosis. To understand the role of transferrin receptor (TFR) and intracellular iron in hepcidin secretion, Chinese hamster ovary transferrin receptor variant (CHO TRVb-1) cells were used that express iron-response-element-depleted human TFRC mRNA (TFRC∆IRE). Results showed that CHO TRVb-1 cells expressed higher basal levels of cell-surface TFR1 than HepG2 cells (2.2-fold; p < 0.01) and following 5 g/L holotransferrin treatment maintained constitutive over-expression at 24h and 48 h, contrasting the HepG2 cells where the receptor levels significantly declined. Despite this, the intracellular iron content was neither higher than HepG2 cells nor increased over time under basal or holotransferrin-treated conditions. Interestingly, hepcidin secretion in CHO TRVb-1 cells exceeded basal levels at all time-points (p < 0.02) and matched levels in HepG2 cells following treatment. While TFRC mRNA expression showed expected elevation (2h, p < 0.03; 4h; p < 0.05), slc40a1 mRNA expression was also elevated (2 h, p < 0.05; 4 h, p < 0.03), unlike the HepG2 cells. In conclusion, the CHO TRVb-1 cells prevented cellular iron-overload by elevating slc40a1 expression, thereby highlighting its significance in the absence of iron-regulated TFRC mRNA. Furthermore, hepcidin response to holotransferrin treatment was similar to HepG2 cells and resembled the human physiological response

Ascorbyl palmitate/DSPE-PEG nanocarriers for oral iron delivery: Preparation, characterisation and in vitro evaluation

The objective of this study was to encapsulate iron in nanocarriers formulated with ascorbyl palmitate and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine polyethylene glycol (DSPE-PEG) for oral delivery. Blank and iron (Fe) loaded nanocarriers were prepared by a modified thin film method using ascorbyl palmitate and DSPE-PEG. Surface charge of the nanocarriers was modified by the inclusion of chitosan (CHI) during the formulation process. Blank and iron loaded ascorbyl palmitate/DSPE nanocarriers were visualised by transmission electron microscopy (TEM) and physiochemical characterisations of the nanocarriers carried out to determine the mean particle size and zeta potential. Inclusion of chitosan imparted a net positive charge on the nanocarrier surface and also led to an increase in mean particle size. Iron entrapment in ascorbyl palmitate-Fe and ascorbyl palmitate-CHI-Fe nanocarriers was 67% and 76% respectively, suggesting a beneficial effect of chitosan on nanocarrier Fe entrapment. Iron absorption was estimated by measuring Caco-2 cell ferritin formation using ferrous sulphate as a reference standard. Iron absorption from ascorbyl palmitate-Fe (592.17 ± 21.12 ng/mg cell protein) and ascorbyl palmitate-CHI-Fe (800.12 ± 47.6 ng/mg, cell protein) nanocarriers was 1.35-fold and 1.5-fold higher than that from free ferrous sulphate, respectively (505.74 ± 23.73 ng/mg cell protein) (n = 6, p < 0.05). This study demonstrates for the first time preparation and characterisation of iron loaded ascorbyl palmitate/DSPE PEG nanocarriers, and that engineering of the nanocarriers with chitosan leads to a significant augmentation of iron absorption

A novel approach to oral iron delivery using ferrous sulphate loaded solid lipid nanoparticles

Iron (Fe) loaded solid lipid nanoparticles (SLN’s) were formulated using stearic acid and iron absorp-tion was evaluated in vitro using the cell line Caco-2 with intracellular ferritin formation as a marker ofiron absorption. Iron loading was optimised at 1% Fe (w/w) lipid since an inverse relation was observedbetween initial iron concentration and SLN iron incorporation efficiency. Chitosan (Chi) was included toprepare chitosan coated SLN’s. Particle size analysis revealed a sub-micron size range (300.3 ± 31.75 nmto 495.1 ± 80.42 nm), with chitosan containing particles having the largest dimensions. As expected,chitosan (0.1%, 0.2% and 0.4% w/v) conferred a net positive charge on the particle surface in a concen-tration dependent manner. For iron absorption experiments equal doses of Fe (20 �M) from selectedformulations (SLN-FeA and SLN-Fe-ChiB) were added to Caco-2 cells and intracellular ferritin proteinconcentrations determined. Caco-2 iron absorption from SLN-FeA (583.98 ± 40.83 ng/mg cell protein)and chitosan containing SLN-Fe-ChiB (642.77 ± 29.37 ng/mg cell protein) were 13.42% and 24.9% greaterthan that from ferrous sulphate (FeSO4) reference (514.66 ± 20.43 ng/mg cell protein) (p ≤ 0.05). Wedemonstrate for the first time preparation, characterisation and superior iron absorption in vitro fromSLN’s, suggesting the potential of these formulations as a novel system for oral iron delivery

Influence of Vitamin D Supplement on Immune Function of the Older Healthy People: A Pilot Randomised Control Trial

Objectives The study aims to investigate the influence of vitamin D (VD) supplement on immune function of the healthy older people. Methods Designed as a randomized control trial, 21 participants (55–85) years old took part and completed the study (20 White, 1 Indian) during May-November 2018 in Coventry, England. The participants were randomized into two groups, VD and control, stratified by age, gender and body mass index (BMI). The VD group (n = 11) took VD3 of 25 μg/day for 12 weeks, while the control group (n = 9) were only provided with educational information of VD. At baseline, 6 weeks and 12 weeks, plasma 25(OH)D levels and immune parameters including phagocytic activity of granulocytes and monocytes, tumour necrosis factor (TNF), interleukin 6 (IL-6), lymphocyte subsets (Th, Tc and natural killer cells), and fast blood glucose and lipid were measured. Dietary VD intake was analysed at baseline and week 12. The data were presented as mean ± standard error (SE) and analysed by two-way repeated measures ANOVA. Results The average age of the participants was (65.8 ± 1.7) years old (67.4 ± 2.7 in VD group and 64.5 ± 2.2 in control group). At baseline, 42.9% of the participants were VD deficiency (25(OH)D 50 nmol/L. There was a significant increase in plasma 25(OH)D concentration in VD group compared with that in the control group (visit*treatment effect p = 0.002). The level of 25(OH)D in the VD group was increased rapidly at 6 weeks (from 38.4 ± 8.7 nmol/L at baseline to 51.0 ± 9.3 nmol/L) and little change has been observed at 12 weeks (51.8 ± 8.6 nmol/L). There was a significant visit*treatment effect (p = 0.036) on the plasma creatinine concentration between two groups, indicating a decrease of plasma creatinine concentration in VD group (from 79.8 ± 7.0 μmol/L at baseline to 75.1 ± 5.4 μmol/L at week 12). There was a significant correlation between body mass index (BMI) and 25(OH)D concentration (P < 0.001). There was no significant effect of VD supplementation on parameters of immune function. Conclusions VD deficiency is common among this older population even during the summertime. VD supplementation at 25 μg/day for 12 weeks showed an anti-inflammatory effect. Funding Sources Coventry University