Antioxidant-loaded mesoporous silica : an evaluation of the physicochemical properties

The dangerous effects of oxidative stress can be alleviated by antioxidants—substances with the ability to prevent damage caused by reactive oxygen species. The adsorption of antioxidants onto nanocarriers is a well-known method that might protect them against rough environ-mental conditions. The aim of this study was to investigate the adsorption and desorption of gallic acid (GA), protocatechuic acid (PCA), chlorogenic acid (CGA), and 4-hydroxybenzoic acid (4-HBA) using commercially available mesoporous silica materials (MSMs), both parent (i.e., SBA-15 and MCM-41) and surface functionalized (i.e., SBA-NH2 and SBA-SH). The MSMs loaded with active compounds were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), thermoporometry (TPM), and powder X-ray diffraction (XRD). High-performance liquid chromatography (HPLC-CAD) was used to evaluate the performance of the adsorption and desorption processes. The antioxidant potential was investigated using the Folin–Ciocalteu (FC) spectrophotometric method. Among the studied MSMs, the highest adsorption of GA was observed for amine-modified SBA-15 mesoporous silica. The adsorption capacity of SBA-NH2 increased in the order of PCA, 4-HBA < GA < CGA. Different desorption effectiveness levels of the adsorbed compounds were observed with the antioxidant capacity preserved for all investigated compounds

Comparison of the Potential Relative Bioaccessibility of Zinc Supplements—In Vitro Studies

The aim of this study was to determine the potential relative bioaccessibility of zinc (Zn) from selected dietary supplements during in vitro digestion. The bioaccessibility of Zn was evaluated in dietary supplements differing in the pharmaceutical form, content, dose, and chemical form of the element. The content of Zn was determined by flame atomic absorption spectrometry. The applied method was validated, and results were characterised by good linearity (R2 = 0.998), recovery (109%), and accuracy (0.02%). As a result of the tests conducted, it was found that the bioaccessibility of Zn from dietary supplements varied and ranged from 1.1% to 9.4%. The highest bioaccessibility was found for zinc diglycinate and the lowest for zinc sulphate. In 9 out of 10 tested dietary supplements, the determined Zn content was higher than the one declared by the producer (up to 161%). The estimated tolerable upper intake level (UL) was exceeded by five of the analysed dietary supplements (123–146%). The analysed dietary supplements were assessed in terms of compliance with the information contained on the product packaging, based on current Polish and European legal regulations. The qualitative assessment was performed according to the United States Pharmacopoeia (USP) guidelines

Assessment of the Mineral Composition and the Selected Physicochemical Parameters of Dietary Supplements Containing Green Tea Extracts

Our aim was to assess the mineral composition as well as the physicochemical quality of green tea-based dietary supplements (capsules and tablets) with respect to average weight, size and shape, friability, breaking force and disintegration time. Products were analysed by flame atomic absorption spectrometry for Ca, K, Mg, Na, Cr, Cu, Fe, Zn, Mn, Pb and Cd. Approximately 60% of the analysed supplements met the requirements of European and Polish regulations. The dietary supplements passed weight variation tests, but not all products had compliant capsule sizes. One product in tablet form failed the friability test, and eleven dietary supplements in tablet form failed the disintegration test. The supplements were characterised by a varied elemental composition, with the highest values found for Ca, Fe, Zn and Mn. The recommended daily allowance realisation for Fe and Zn in two dietary supplements (capsule form) exceeded 100%. As a result of the estimation of the monthly intake of toxic metals, it was concluded that the tested products do not pose a risk to consumer health. Significant relationships (p &lt; 0.001) were found for K, Mg, Na, Cu, Fe, Mn and Zn. The application of factor and cluster analyses allowed the verification of the similarity of green tea extracts contained in dietary supplements to the natural raw material, green tea leaves, used as a reference material

Genetic Variability of Hepatitis C Virus (HCV) 5' Untranslated Region in HIV/HCV Coinfected Patients Treated with Pegylated Interferon and Ribavirin.

Association between hepatitis C virus (HCV) quasispecies and treatment outcome among patients with chronic hepatitis C has been the subject of many studies. However, these studies focused mainly on viral variable regions (E1 and E2) and usually did not include human immunodeficiency virus (HIV)-positive patients. The aim of the present study was to analyze heterogeneity of the 5' untranslated region (5'UTR) in HCV/HIV coinfected patients treated with interferon and ribavirin. The HCV 5'UTR was amplified from serum and peripheral blood mononuclear cells (PBMC) samples in 37 HCV/HIV coinfected patients treated for chronic hepatitis C. Samples were collected right before treatment, and at 2, 4, 6, 8, 12, 20, 24, 36, 44, 48, 60, and 72 weeks. Heterogeneity of the 5'UTR was analyzed by single strand conformational polymorphism (SSCP), cloning and sequencing. Sustained virological response (SVR) was achieved in 46% of analyzed HCV/HIV co-infected patients. Stable SSCP band pattern was observed in 22 patients (62.9%) and SVR rate among these patients was 23%. Decline in the number of bands and/or shift in band positions were found in 6 patients (17.1%), 5 (83%) of whom achieved SVR (p=0.009). A novel viral genotype was identified in all but one of these patients. In 5 of these 6 patients a new genotype was dominant. 5'UTR heterogeneity may correlate with interferon and ribavirin treatment outcome. In the analyzed group of HCV/HIV coinfected patients, viral quasispecies stability during treatment favored viral persistence, whereas decrease in the number of variants and/or emergence of new variants was associated with SVR. Among injection drug users (IDU) patients, a new genotype may become dominant during treatment, probably due to the presence of mixed infections with various strains, which have different susceptibility to treatment

Different patterns of single-strand conformation polymorphism (SSCP) analysis of 5’untranslated region.

<p>A, comparison of SSCP band patterns in serum and PBMC before treatment; B, no changes in SSCP band pattern during treatment; C, decline in the number of SSCP bands without a shift in band positions; D, ‘shift’ in SSCP band pattern indicative of sequence changes. HCV RNA was amplified from serum (s) and PBMC (p) at numerous time-points (see the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0125604#sec002" target="_blank">Methods</a> section), but only positive samples are shown; w, weeks.</p

Multiple sequences alignment of 5’UTR variants detected in serum (s) and PBMC (p) of six patients with chronic hepatitis C in whom changing SSCP band pattern (shift) was suggestive of sequence changes.

<p>Dots indicate consensus positions. Six to 12 clones were analyzed for each particular time point and compartment. Only clones with different sequences are shown and the number of clones representing each sequences is provided in the Figure.</p