Binding mechanism and bioavailability of a novel phosvitin phosphopeptide (Glu-Asp-Asp-pSer-pSer) calcium complex.

Phosvitin has excellent calcium binding capacity, related to its phosphopeptides. The phosphopeptides may be used as functional ingredients for improving calcium bioavailability, but the calcium-binding mechanism is unclear. In this study, a novel phosvitin phosphorylated pentapeptide (Glu-Asp-Asp-pSer-pSer, EDDpSpS) was selected to prepare an EDDpSpS calcium complex (EDDpSpS-Ca), and the calcium-binding mechanism and bioavailability investigated. The calcium-binding capacity of EDDpSpS was up to 468 ± 152.80 mg/g. Calcium ions prompted the folding of the EDDpSpS structure to form spherical nanoparticles. The calcium binding sites of EDDpSpS involved peptide bonds, carboxyl, amino, and phosphate groups. Molecular forces involved in these interactions were electrostatic in nature. Moreover, EDDpSpS-Ca had excellent bioavailability when compared to CaCO3, calcium lactate, and d-calcium gluconate. This study revealed the calcium-binding mechanism of phosvitin phosphopeptide, and suggested that EDDpSpS-Ca has the potential to be a novel, efficient, and promising calcium supplement.

A water-soluble polysaccharide from Eucommia folium: the structural characterization and anti-tumor activity in vivo.

In this study, a water-soluble polysaccharide from Eucommia folium was extracted by hot water and purified using Sephadex G-200 gel columns. The results showed that the purified fraction (EFP) has a molecular weight of 9.98 × 105 Da and consisted of rhamnose, arabinose, galactose, glucose, mannose, xylose, galacturonic acid, and glucuronic acid (molar ratio: 0.226: 1.739: 2.183: 1: 0.155: 0.321: 0.358: 0.047). The combination of infrared spectroscopy and NMR analysis proved that EFP is an acidic polysaccharide whose main chain consists of α-L-Araf-(1 → , → 3,5)-α-Araf-(1 → , → 3)-ß-Galp-(1 → , → 3,6)-ß-Glcp-(1 → , → 2)-α-D-Manp-(1 → , → 4)-α-GalpA-(1 → , → 2,4)-α-Rhap-(1 → . In addition, the in vivo antitumoral activity of EFP was studied using a H22 tumor-bearing mice model. EFP effectively inhibited tumor growth in mice following intragastric administration. By Combining with the results of the apoptosis assay and JC-1 staining analysis, we confirmed that EFP induces apoptosis through the mitochondrial pathway. Furthermore, cell cycle analysis demonstrated that EFP blocks the cell cycle at S phase.

Protective Effect of the Polysaccharides from Taraxacum mongolicum Leaf by Modulating the p53 Signaling Pathway in H22 Tumor-Bearing Mice.

Dandelion is an edible plant with a variety of bioactive components. This paper mainly reports the antitumor activity of dandelion polysaccharide DLP120 on H22 tumor-bearing mice. DLP120 is an acidic polysaccharide composed of pectin and arabinogalactan. The results indicate that DLP120 markedly inhibited tumor growth in a dose-dependent manner and attenuated and regulated negative effects on organs. In addition, DLP120 not only increased the viability of spleen lymphocytes and natural killer (NK) cells, but also increased the proportion of lymphocyte subsets in peripheral blood. Furthermore, Hematoxylin-Eosin (HE) staining showed that tumor tissues and cells exhibited typical pathology features. Annexin V FITC/PI staining and cell cycle distribution results further confirmed apoptosis and cell cycle arrest in S and G2 phases. Notably, there was a significant accumulation of reactive oxygen species. Western blotting results demonstrated that the expression of p53 was up-regulated in the DLP120 group. Moreover, the pro-apoptotic protein Bax was up-regulated while the inhibitory-apoptotic protein Bcl-2 was down-regulated. In addition, the expression of Fas and FasL, associated with the death receptor pathway, were also up-regulated. Overall, administration of DLP120 in H22 tumor-bearing mice can not only enhance immunity but also directly induce tumor cell apoptosis.

Extraction, characterization, and in vivo antitumor activity of a novel polysaccharide from Coriandrum sativum L.

A novel polysaccharide was extracted from Coriandrum sativum L. at a yield of 4.56 ± 0.17% (n = 3). The extraction was optimized using response surface methodology: powder-to-liquid ratio 1:21 g/ml, extraction time 188 min, temperature 81°C, and three replicate extractions. The purified polysaccharide had an average molecular weight of 1.30 × 106 Da and was composed of rhamnose, arabinose, galactose, glucose, and galacturonic acid in molar ratios of 1.52: 8.14: 20.85: 1: 2.42 with α-L-Araf-(1→, →6)-ß-D-Galp-(1→, →4)-α-GalpA-(1→ and →2, 4)-α-Rhap-(1→). In vivo tests demonstrated that the polysaccharide suppressed H22 tumor growth in mice and protected the immune organs. Annexin V-FITC/PI, PI, and JC-1 staining showed that the primary mechanism of tumor inhibition was the induction of apoptosis and S-phase arrest with apoptosis achieved via a mitochondrial pathway. PRACTICAL APPLICATIONS: Coriandrum sativum L. is used as a culinary spice but its medicinal value has also been widely recognized. A novel polysaccharide was extracted from this herbaceous plant and its structure and bioactivity were investigated. This high-molecular-weight polysaccharide exhibited antitumor effects against H22 cells in mice and had potential to be developed as an anti-liver cancer medicine and functional food supplement.

The Structural Characteristics of an Acidic Water-Soluble Polysaccharide from Bupleurum chinense DC and Its In Vivo Anti-Tumor Activity on H22 Tumor-Bearing Mice.

This study explored the preliminary structural characteristics and in vivo anti-tumor activity of an acidic water-soluble polysaccharide (BCP) separated purified from Bupleurum chinense DC root. The preliminary structural characterization of BCP was established using UV, HPGPC, FT-IR, IC, NMR, SEM, and Congo red. The results showed BCP as an acidic polysaccharide with an average molecular weight of 2.01 × 103 kDa. Furthermore, we showed that BCP consists of rhamnose, arabinose, galactose, glucose, and galacturonic acid (with a molar ratio of 0.063:0.788:0.841:1:0.196) in both α- and ß-type configurations. Using the H22 tumor-bearing mouse model, we assessed the anti-tumor activity of BCP in vivo. The results revealed the inhibitory effects of BCP on H22 tumor growth and the protective actions against tissue damage of thymus and spleen in mice. In addition, the JC-1 FITC-AnnexinV/PI staining and cell cycle analysis have collectively shown that BCP is sufficient to induce apoptosis and of H22 hepatocarcinoma cells in a dose-dependent manner. The inhibitory effect of BCP on tumor growth was likely attributable to the S phase arrest. Overall, our study presented significant anti-liver cancer profiles of BCP and its promising therapeutic potential as a safe and effective anti-tumor natural agent.

Structural Characteristic and In-Vitro Anticancer Activities of Dandelion Leaf Polysaccharides from Pressurized Hot Water Extraction.

Dandelion (Taraxacum mongolicum Hand.-Mazz.) is a medicinal and edible plant. Dandelion has great development value for its health promoting benefits; additionally, Dandelion grows almost anywhere in the world. In this study, we report the structural characteristics and anti-cancer activity of novel dandelion leaf polysaccharides extracted by pressurized hot water extraction at 120 °C (DLP120) with Mw relative to dextran of 1.64 × 106 Da. Structural analysis indicated that DLP120 is a complex polysaccharide composed of pectin and arabinogalactan. It was mainly composed of arabinose (32.35 mol%) and galactose (44.91 mol%). The main glycosidic linkages of DLP120 were 4-ß-D-Galp, 4-α-D-GalpA, T-ß-D-Galp, 5-α-L-Araf, 3,5-α-L-Araf, and T-α-L-Araf. In vitro, DLP120 inhibited HepG2 cell proliferation in a dose-dependent manner by inducing cell apoptosis. Cell cycle detection results revealed that DLP120 mainly arrests the cell cycle in S phase. Cells treated with DLP120 displayed obvious apoptotic morphology, including cell volume shrinks and cytoskeleton breaks down. In short, DLP120 has potential as an anti-cancer agent.

Sludge-based activated carbon catalyzed H2O2 oxidation of reactive azo dyes.

Sludge-based activated carbon (ZAC) was successfully employed as both adsorbent and catalyst for the oxidation process of reactive yellow 86 (RY86) and reactive black 5 (RB5). Physicochemical properties of the prepared sewage sludge-derived activated carbon were evaluated by N2 adsorption/desorption, Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The effects of parameters such as initial pH, H2O2 concentrations, ZAC dosages, dye concentrations and temperature on the removal of RY86 and RB5 were investigated. Kinetics results showed that the adsorption rates of RY86 and RB5 by ZAC can be approximated by the pseudo-first order model, and that the oxidation rates by Behnajady-Modirshahla-Ghanbery (BMG) model. Under the optimum conditions in the experiment, i.e. pH = 6.0, T = 303 K, [H2O2] = 49.5 mmol/L, [ZAC] = 4 g/L, [dyes] = 300 mg/L and t = 150 min, 99%, 88% and 84% of colour, COD and TOC were removed by Fenton -like oxidation for RY86, while for RB5, the three removal rates were 90%, 70% and 62%, respectively, indicating that sludge-based activated carbon can be used as an effective catalyst to oxidation of dyes by H2O2 from coloured wastewater.