Zhengxiang Ning

Structure Characterization of a Novel Polysaccharide from Dictyophora indusiata and Its Macrophage Immunomodulatory Activities

A novel polysaccharide, here named DP1, was isolated from the fruiting body of Dictyophora indusiata using a water extraction method. Structure characterization revealed that DP1 had an average molecular weight of 1132 kDa and consisted of glucose (56.2%), galactose (14.1%), and mannose (29.7%). The main linkage type of DP1 were proven to be (1 → 3)-linked α-l-Man, (1 → 2,6)-linked α-d-Glc, (1 → 6)-linked β-d-Glc, (1 → 6)-linked β-d-Gal, and (1 → 6)-linked β-d-Man by periodate oxidation-Smith degradation and nuclear magnetic resonance analysis. The immunostimulating assay indicated that DP1 could significantly promote macrophage NO, TNF-α, and IL-6 secretion in murine RAW 264.7 cells involving complement receptor 3 (CR3). The immune activities of DP1 were quite stable under thermal processing (100, 121, and 145 °C). Besides, DP1 retained stability after acidic/alkline treatment (pH 4.0-10.0), which enabled it to be an ideal complementary medicine or functional food for therapeutics of hypoimmunity and immunodeficiency diseases.

Intracellular Antioxidant Detoxifying Effects of Diosmetin on 2,2-Azobis(2-amidinopropane) Dihydrochloride (AAPH)-Induced Oxidative Stress through Inhibition of Reactive Oxygen Species Generation

The intracellular antioxidant activities of diosmetin were evaluated by cellular antioxidant activity (CAA) assay, 2,2-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced erythrocyte hemolysis assay and cupric chloride (CuCl2)-induced plasma oxidation assay. The results showed that diosmetin exhibits strong cellular antioxidant activity (EC50 = 7.98 μmol, CAA value = 58 μmol QE/100 μmol). It was also found that diosmetin treatment could effectively attenuate AAPH-induced erythrocyte hemolysis (91.0% inhibition at 100 μg/mL) and CuCl2-induced plasma oxidation through inhibition of intracellular reactive oxygen species (ROS) generation. Diosmetin could significantly restore AAPH-induced increase of intracelluar antioxidant enzyme (SOD, GPx, and CAT) activities to normal levels, as well as inhibit intracellular malondialdehyde (MDA) formation. Thus, the intracellular antioxidant detoxifying mechanism of diosmetin is associated with both nonenzymatic and enzymatic defense systems.

Preparation and Characterization of Dictyophora indusiata Polysaccharide-Zinc Complex and Its Augmented Antiproliferative Activity on Human Cancer Cells.

Dictyophora indusiata polysaccharide (DP1) was successfully chelated with zinc chloride to achieve its enhanced antiproliferative activity. The obtained DP1-Zn complex showed significant antiproliferative activity (18.1 ± 2.84% viability of MCF-7 cells at 250 μg/mL) on a group of human cancer cell lines through induction of apoptosis. The pro-apoptotic action of DP1-Zn was confirmed by morphological changes including chromatin condensation, DNA breakage, and S phase cell cycle arrest in human breast adenocarcinoma cells (MCF-7). The DP1-Zn-induced apoptotic pathways were characterized by the activation of caspases-3, -8, and -9, mitochondrial dysfunction, and reactive oxygen species (ROS) overproduction (305 ± 7.06% production of control at 250 μg/mL). This study suggested that DP1-Zn can be developed as a candidate for cancer treatment and prevention, especially human breast adenocarcinoma.

Structure-Activity Relationship of Flavonoids Active Against Lard Oil Oxidation Based on Quantum Chemical Analysis

In this study, the antioxidant activities of 15 flavonoids against lard oil oxidation were determined by using the Rancimat test. Quercetin, dihydromyricetin, luteolin and kaempferol showed the strongest antioxidant activity, with protection factor values (PF) of 11.50, 11.29, 4.24 and 2.49, respectively. The role of conjugated hydroxyl groups of the B and C ring is discussed. By using the following descriptors: ΔHf (the difference in heat of formation between flavonoids and their free radicals resulted after hydrogen atom donation) and HBC (the number of conjugated hydroxyl groups of the B and C ring), the result obtained in the antioxidant Rancimat test could be successfully explained.

Biofunctionalization of Selenium Nanoparticle with Dictyophora Indusiata Polysaccharide and Its Antiproliferative Activity through Death-Receptor and Mitochondria-Mediated Apoptotic Pathways.

Bio-functionalized nanoparticles with semiconducting/metallic core encapsulated in a bio- or bio-derived materials are promising for applications in biology and especially in cancer diagnostic and healing. In this report, we report a facile, single-step, first-time synthesis and in-situ functionalization strategy for the preparation of monodispersed selenium nanoparticles (SeNPs) functionalized using a novel polysaccharide (DP1) extracted from Dictyophora indusiata (a fungus). The DP1 functionalized SeNPs (DP1-SeNPs), where DP1 is attached to the surface via Se-O bond as well as physic-sorption had, an average diameter of 89 nm, and were highly uniform, extremely stable compared to bare SeNPs. Detailed investigation of the biological properties of DP1-SeNP illustrated that they exhibit unprecedented, enhanced, and selective antiproliferative activity through inducing cell apoptosis confirmed by nuclear condensation, DNA cleavage, and accumulation of S phase cell arrest. The mechanism of the induced apoptosis was found to be a combination of the activation of caspases 3, 8, and 9, the Fas-associated death domain protein (FADD), reactive oxygen species (ROS) overproduction, as well as mitochondrial dysfunction. It is envisioned that the reported DP1-SeNPs will offer a new phase space for high-efficiency anticancer treatment with little side effect.

Tyrosinase inhibitory effects and antioxidative activities of novel cinnamoyl amides with amino acid ester moiety

Nine cinnamoyl amides with amino acid ester (CAAE) moiety were synthesized by the conjugation of the corresponding cinnamic acids (cinnamic acid, 4-hydroxy cinnamic acid, ferulic acid and caffeic acid) with amino acid esters, and their inhibitory effects on the activities of mushroom tyrosinase were investigated, using l-3,4-dihydroxyl-phenylalanine (l-DOPA) as the substrate. Among these CAAE amides, ethyl N-[3-(4-hydroxy-3-methoxyphenyl)-1-oxo-2-propen-1-yl]-l-phenylalaninate (b(4)) showed the strongest inhibitory activity; the IC(50) was 0.18 μM. The IC(50) values, inhibition types, inhibition mechanisms and kinetics of all these CAAE amides were evaluated. A structure-activity relationship (SAR) study found that the inhibitory effects were potentiated with the increasing length of hydrocarbon chains at the amino acid esters and also influenced by the substituents at the styrene groups. Furthermore, the hydroxyl radical scavenging and anti-lipid peroxidation activities of four CAAE derivatives were also investigated. Among these compounds, b(3) (ethyl N-[3-(3,4-dihydroxyphenyl)-1-oxo-2-propen-1-yl]-l-phenylalaninate) and b(4) exhibited potential antioxidant activities.

Development of a Sono-Assembled, Bifunctional Soy Peptide Nanoparticle for Cellular Delivery of Hydrophobic Active Cargoes

Soy proteins are prone to aggregate upon proteolysis, hindering their sustainable development in food processing. Here, a continuous work on the large insoluble peptide aggregates was carried out, aiming to develop a new type of soy peptide-based nanoparticle (SPN) for active cargo delivery. Sono-assembled SPN in spherical appearance and core-shell structure maintained by noncovalent interactions was successfully fabricated, exhibiting small particle size (103.95 nm) in a homogeneous distribution state (PDI = 0.18). Curcumin as a model cargo was efficiently encapsulated into SPN upon sonication, showing high water dispersity (129.6 mg/L, 104 higher than its water solubility) and storage stability. Additionally, the pepsin-resistant SPN contributed to the controlled release of curcumin at the intestinal phase and thus significantly improved the bioaccessibility. Encapsulated curcumin was effective in protecting glutamate-induced toxicity in PC12 cells, where the matrix SPN can simultaneously reduce lipid peroxidation and elevate antioxidant enzymes levels, innovatively demonstrating its bifunctionality during cellular delivery.

Structural Design and Physicochemical Foundations of Hydrogels for Biomedical Applications

Biomedical research, known as medical research, is conducive to support and promote the development of knowledge in the field of medicine. Hydrogels have been extensively used in many biomedical fields due to their highly absorbent and flexible properties. The smart hydrogels, especially, can respond to a broad range of external stimuli such as temperature, pH value, light, electric and magnetic fields. With excellent biocompatibility, tunable rheology, mechanical properties, porosity, and hydrated molecular structure, hydrogels are considered as promising candidate for simulating local tissue microenvironment. In this review article, we mainly focused on the most recent development of engineering synthetic hydrogels; moreover, the classification, properties, especially the biomedical applications including tissue engineering and cell scaffolding, drug and gene delivery, immunotherapies and vaccines, are summarized and discussed.