Effect of a polysaccharide-rich hydrolysate from Saccharomyces cerevisiae (LipiGo®) in body weight loss: randomised, double-blind, placebo-controlled clinical trial in overweight and obese adults.

BACKGROUND: In the present study we evaluated the weight loss effect of a polysaccharide-rich food supplement, LipiGo®, comprising a specific ß-glucan-chitin-chitosan fraction (BGCC) obtained from the chemical hydrolysis of Saccharomyces cerevisiae, resulting as a by-product of the brewing process. RESULTS: A randomised, double-blind, placebo-controlled clinical trial was performed enrolling 56 overweight and obese subjects (body mass index, BMI, 25-35 kg m-2 ) who were not following any specific diet, and were given placebo or BGCC (3 g d-1 ) for 12 weeks. Results were analysed by intention-to-treat (ITT) and per-protocol (PP) methods. Body weight increased in the placebo group compared to baseline (ITT: 1.0 kg, P < 0.001; PP: 1.5 kg, P = 0.003), while it was slightly lowered in the BGCC group (ITT: -0.8 kg, P = 0.210; PP: -1.1 kg, P = 0.182). BGCC, but not the consumption of placebo, also resulted in a reduction of waist circumference and body fat compared to baseline. CONCLUSIONS: Results suggest that daily supplementation of BGCC may be useful for improving body weight and waist circumference in overweight and obese subjects, without relevant adverse effects. © 2017 Society of Chemical Industry.

Recovery from dietary iron deficiency anaemia in rats by the intake of microencapsulated ferric saccharate.

This study examined the bioavailability of iron contained in microencapsulated ferric saccharate in a rat model of iron deficiency anaemia. Three groups of male Sprague-Dawley rats with induced iron deficiency anaemia were subsequently treated with a control Fe-deficient diet (2-6 mg Fe/Kg of diet) with or without the addition of 10 mg Fe/Kg of diet (in form of ferrous sulphate or microencapsulated ferric saccharate) for 2 weeks. The bioavailability of microencapsulated ferric saccharate was examined by measuring body weight gain, feed efficiency and reticulocyte parameters, and compared with the bioavailability of ferrous sulphate. Final body weight, feed efficiency, mean corpuscular volume of reticulocytes and average haemoglobin content in reticulocytes were significantly higher in anaemic rats supplemented with either microencapsulated ferric saccharate or ferrous sulphate, compared to anaemic controls. No significant differences were found between the two iron-supplemented groups. The total number of reticulocytes showed a similar trend. The results demonstrated that ingestion of microencapsulated ferric saccharate is as effective as ferrous sulphate in recovery from iron deficiency anaemia.

Comparative study of the oral absorption of microencapsulated ferric saccharate and ferrous sulfate in humans.

PURPOSE: Our objective was to compare the absorption of microencapsulated ferric saccharate (MFS) and ferrous sulfate (FS) in a fortified milk product, using a crossover design. METHODS: Seventeen non-iron-deficient healthy adults from both sexes participated in the study. On each intervention day (days 1 and 8), after an overnight fast, the volunteers consumed one type of product (test or control) and blood sampling was carried out at different times. The interventions days were separated by 7-day washout periods. This study was double blinded, crossover and randomized for nature of the test meals. The primary outcomes of the study were total serum iron and transferrin saturation. RESULTS: No significant differences could be observed in serum iron concentration during the 6-h postprandial study due to the type of milk product consumed, and there was neither an effect of time nor an interaction between the type of milk product and time. Transferrin saturation significantly increased after the intake of both products (P < 0.005), reaching a peak value between hours 2 and 4. No significant differences were detected between MFS and FS, indicating that iron absorption from MFS is equivalent to absorption from FS. CONCLUSIONS: MFS is a new ingredient that allows the fortification of a wide range of food products, including heat-processed and non-acidic products with similar absorption to FS, designed to produce neither organoleptic changes nor off-color development during storage of fortified food.

New approach to measure protein binding based on a parallel artificial membrane assay and human serum albumin.

We report here a new, label-free approach to measure serum protein binding constants. The assay is able to measure HSA K d values in the milli-molar to micromolar range. The protein is not immobilized on any surface and the assay self-corrects for nonspecific adsorption. No mass balance is required to get accurate binding constants and it is not necessary to wait for equilibrium to extract the binding constant. The assay runs in a 96-well format using commercially available parts and is, therefore, relatively easy to implement and automate. As the chemical membranes used are not water permeable, there is no volume change due to the osmotic pressure and pretreatment (soaking) is not necessary. The concept can potentially be extended to other proteins and could thus serve as a label-free technique for general binding constant measurements.

Characterization of the acidity of residual silanol groups in immobilized artificial membranes.

Residual silanol acidity and activity of one immobilized artificial membrane (IAM) column have been measured from the retention of LiNO(3) in the column with a methanol/buffer (1mM in Na(+)) (60:40, v/v) mobile phase buffered to different pH values. Just one type of silanol with pssK(a)=7.61 (near the pH limit recommended by the manufacturer) was found, although these silanols show large activity. The results obtained have been compared with those obtained previously for Resolve C18, Resolve Silica, Symmetry C18, Symmetry Silica, XTerra MS C18, underivatized XTerra, Lichrospher 100 RP-18, Purospher RP-18e, Luna C18 (2) and Chromolith Perfomance RP-18e, showing that the IAM column is similar to Luna C18 and Symmetry C18 in terms of silica quality, as measured by Li(+) retention. A warning about the use of IAM columns for emulation of biological systems at physiological pH 7 is given because the ionized silanols may contribute to the retention of some drugs at this pH.

Interaction of antioxidant biobased epicatechin conjugates with biomembrane models.

(-)-Epicatechin conjugates with sulfur-containing moieties are strong free radical scavengers with cell-protecting activities, which may be in part modulated by their capacity to bind to biological membranes. We present here a study of the interaction of these conjugates with membrane models such as multilamellar vesicles and a phospholipid-coated silica column (immobilized artificial membrane), monitored by differential scanning calorimetry and high-performance liquid chromatography, respectively. The nonpolyphenolic moiety significantly influenced the membrane behavior of the whole molecules. Bulky and hydrophobic conjugates clearly interacted with the phospholipids and may have a tendency to penetrate into the hydrophobic core of the vesicles. In contrast, the smaller cationic 4beta-(2-aminoethylthio)epicatechin may be located at the outer interface of the lipid membrane. The outcomes from both experimental set-ups were in good agreement. The differences detected in the biological activities of the conjugates may be explained in part by their tendency to penetrate the cell membrane.

Chromatographic estimation of drug disposition properties by means of immobilized artificial membranes (IAM) and C18 columns.

Chromatographic retention measurement in immobilized artificial membranes (IAMs) is considered a fast and reliable method to predict biological properties (drug distribution) because of the IAM structure, which consists of phospholipid analogues bonded covalently to silica particles. A new parameter (d) is proposed to estimate the similarity between IAM columns, conventional HPLC columns, and drug distribution systems, and thus the performance of chromatographic systems to predict drug distribution. An IAM.PC.DD2 column has been used for this study, together with two XTerra columns (MSC18 and RP18), at several acetonitrile-water mobile phases. According to the d parameter, good correlations should be obtained between chromatographic systems (both IAM and C18) and octanol-water partition coefficient (log P), and thus both types of columns could be used to obtain log P values. The IAM.PC.DD2 system shows a close similarity to human skin partition, tadpole narcosis, and blood-brain permeability processes, showing that it can be useful as a model for these biological processes. Controversially, it is shown that human skin permeation is more similar to C18 partition than to IAM partition. Other biological processes such as blood-brain distribution and tissue-blood partition show a poor similarity to IAM and C18 systems, demonstrating that estimation of these drug distribution processes by chromatographic measurements may not be adequate.

Characterization of immobilized artificial membrane (IAM) and XTerra columns by means of chromatographic models.

Immobilized artificial membranes (IAMs) prepared from phosphatidylcholine analogs are used as stationary phases in liquid chromatography systems to model drug partitioning between an aqueous phase (mobile phase) and a cell membrane (IAM column). Two different chromatographic models, which describe retention as a function of solute and column-mobile phase properties, have been applied to characterization of an IAM and two reversed phase C18 columns (Waters XTerra MSC18 and XTerra RP18) with acetonitrile-water mobile phases. The comparison of the results shows that the phosphatidylcholine group makes IAM column more polar than both XTerra columns, specially in terms of hydrogen-bond acceptor ability. XTerra RP18 is slightly more polar than XTerra MSC18 because of the presence of the embedded carbamate polar group.

Prediction of retention in reversed-phase liquid chromatography by means of the polarity parameter model.

The polarity parameter model previously developed: log k=(log k)(0) + p(P(m)(N) - P(s)(N)) has been successfully applied to study several chromatographic systems involving new generation RPLC columns (Luna C18, Resolve C18, XTerra MSC18, and XTerra RP18). In this model the retention of the solutes (log k) is related to a solute parameter (p), a mobile phase parameter (P(m)(N)) and two chromatographic system parameters [P(s)(N) and (log k)(0)]. The studied systems have been characterized with different acetonitrile-water and methanol-water mobile phases, using a set of 12 neutral solutes of different chemical nature. The polarity parameter model allows prediction of retention of any solute in any mobile phase composition just using the retention data obtained in one percentage of organic modifier and the polarity parameters established in the characterization of the chromatographic systems. This model also allows the solute polarity data transference between RPLC characterized systems, so it is possible to predict the retention in various RPLC systems working experimentally with just one of them. Moreover, the global solvation parameter model has also been applied to the same chromatographic systems using a wide set of solutes in order to compare its predictive ability with the one of the polarity parameter model. The results clearly show that both models predict retention with very similar accuracy but the polarity parameter model requires much less preliminary experimental measurements to achieve equivalent results than the global solvation approach.