Solid-State Reaction Synthesis of MgAl2O4 Spinel from MgO-Al2O3 Composite Particles Prepared via Electrostatic Adsorption.

This paper presents the formation of magnesium aluminate spinel using composite particles prepared via electrostatic adsorption (ESA). Scanning electron microscopy (SEM) images confirmed the presence of Al2O3-MgO composite particles. A mixture of Al2O3 and MgO raw materials was also prepared by using the conventional bead-milling method for comparison. The samples sintered at elevated temperatures were characterized through X-ray diffraction, SEM, and relative density measurements. Additionally, the lattice parameter and strain of the samples were determined using the Nelson-Riley function and the Williamson-Hall equation. A pure spinel phase formed in the ESA-derived sample sintered at 1400 °C, while the MgO structure remained in the conventionally prepared sample sintered at 1600 °C. The densities of samples sintered at 1450 °C or higher exceeded 90%. The lattice strain of the prepared samples was inversely proportional to the sintering temperature, attributed to the formation of large grains at higher temperatures. However, the sample sintered at 1600 °C for 8 h exhibited the highest strain of 0.0074 because the crystals grew in a certain direction.

Secondary metabolites from Valeriana jatamansi with their anti-inflammatory activity.

Valeriana jatamansi is hired as multiple remedies for treatment of insomnia, blood and circulatory disorders, asthma, dry cough, jaundice, seminal weakness, cardiac debility, and skin diseases in Vietnam. Our research discovered the phytochemical investigation of constituents from this herbal medicine resulted in the isolation of two new compounds (jatamansides A (4) and B (7)) together with 16 known ones from the whole plant. Their structures were established by using spectroscopic techniques (multinuclear and multidimensional nuclear magnetic resonance, infrared, ultraviolet-visible), mass spectrometry, hydrolysis analysis, or comparing their NMR data to those reported in the literature. In addition, all the isolates were evaluated for their inhibitory effect against TNF-α production in LPS-stimulated on RAW264.7 cells with significant inhibition.

Chemical constituents of Vietnamese mangrove Hibiscus tiliaceus with antioxidant and alpha-glucosidase inhibitory activity.

Using various chromatographic techniques, a total of 15 compounds, including one novel megastigmane named tiliaceic acid A (1) and 14 known compounds, were isolated from the traditional medicinal Vietnamese mangrove Hibiscus tiliaceus. Their structures were confirmed based on spectroscopic experiments including, UV, 1 D- and 2 D-NMR, HR-ESI-MS, and ECD analysis. The antioxidant and α-glucosidase inhibitory activities of the isolated compounds from H. tiliaceus were evaluated for the first time. Compound 2 showed strong α-glucosidase inhibitory activity with an IC50 of 77.78 ± 1.00 µM compared with the positive control acarbose at 105.71 ± 2.29 µM.

Enhancement of an In Vivo Anti-Inflammatory Activity of Oleanolic Acid through Glycosylation Occurring Naturally in Stauntonia hexaphylla.

Stauntonia hexaphylla (Lardizabalaceae) has been used as a traditional herbal medicine in Korea and China for its anti-inflammatory and analgesic properties. As part of a bioprospecting program aimed at the discovery of new bioactive compounds from Korean medicinal plants, a phytochemical study of S. hexaphylla leaves was carried out leading to isolation of two oleanane-type triterpene saponins, 3-O-[ß-d-glucopyranosyl (1→2)-α-l-arabinopyranosyl] oleanolic acid-28-O-[ß-d-glucopyranosyl (1→6)-ß-d-glucopyranosyl] ester (1) and 3-O-α-l-arabinopyranosyl oleanolic acid-28-O-[ß-d-glucopyranosyl (1→6)-ß-d-glucopyranosyl] ester (2). Their structures were established unambiguously by spectroscopic methods such as one- and two-dimensional nuclear magnetic resonance and infrared spectroscopies, high-resolution electrospray ionization mass spectrometry and chemical reactions. Their anti-inflammatory activities were examined for the first time with an animal model for the macrophage-mediated inflammatory response as well as a cell-based assay using an established macrophage cell line (RAW 264.7) in vitro. Together, it was concluded that the saponin constituents, when they were orally administered, exerted much more potent activities in vivo than their sapogenin core even though both the saponins and the sapogenin molecule inhibited the RAW 264.7 cell activation comparably well in vitro. These results imply that saponins from S. hexaphylla leaves have a definite advantage in the development of oral medications for the control of inflammatory responses.

Enhanced Degradation of Diesel Oil by Using Biofilms Formed by Indigenous Purple Photosynthetic Bacteria from Oil-Contaminated Coasts of Vietnam on Different Carriers.

Oil pollution in marine environment caused by oil spillage has been a main threat to the ecosystem including the ocean life and to the human being. In this research, three indigenous purple photosynthetic strains Rhodopseudomonas sp. DD4, DQ41, and FO2 were isolated from oil-contaminated coastal zones in Vietnam. The cells of these strains were immobilized on different carriers including cinder beads (CB), coconut fiber (CF), and polyurethane foam (PUF) for diesel oil removal from artificial seawater. The mixed biofilm formed by using CB, CF, and PUF as immobilization supports degraded 90, 91, and 95% of diesel oil (DO) with the initial concentration of 17.2 g/L, respectively, after 14 days of incubation. The adsorption of DO on different systems was accountable for the removal of 12-16% hydrocarbons for different carriers. To the best of our knowledge, this is the first report on diesel oil degradation by purple photosynthetic bacterial biofilms on different carriers. Moreover, using carriers attaching purple photosynthetic bacteria to remove diesel oil in large scale is considered as an essential method for the improvement of a cost-effective and efficient bioremediation manner. This study can be a promising approach to eliminate DO from oil-contaminated seawater.

Ginsenosides from Korean red ginseng modulate T cell function via the regulation of NF-AT-mediated IL-2 production.

Korean red ginseng is a traditional health food frequently used to prevent or treat various diseases worldwide. In this study, we evaluated the immunomodulatory activities of eleven compounds (1-11) isolated from Korean red ginseng, focusing on T cell function. First, the effects of the eleven compounds were studied on the regulation of IL-2, a potent T cell growth factor. Compounds 5, 7, and 9 significantly increased IL-2 secretion in phorbol 12-myristate 13-acetate (PMA)/ionomycin (Io)-induced EL-4 T cells. Next, we examined the effects of compounds 5, 7, and 9 on the regulation of transcription factors related to IL-2 production in T cells. Compound 9 significantly increased the PMA/Io-induced promoter activity of nuclear factor of activated T cells (NF-AT) in EL-4 T cells, but did not have any significant effects on the promoters of NF- κB. These results suggest that compound 9 activates T cell function via the regulation of NF-AT-mediated IL-2 production.

Phytochemical profile of Syzygium formosum (Wall.) Masam leaves using HPLC-PDA-MS/MS and a simple HPLC-ELSD method for quality control.

Syzygium formosum (SF) leaves have been used for thousands of years in traditional Vietnamese medicine for the treatment of allergy or skin rash. However, the role of the phytochemical profile of SF leaves on their activities is poorly understood. Additionally, there is currently no quality control method for this herbal material, which is required by the pharmaceutical industry. Therefore, this study aimed to investigate chemical profile of SF leaves using high-performance liquid chromatography-photodiode array-tandem mass spectrometry (HPLC-PDA-ESI-MS/MS) and establish a simple and efficient HPLC method for controlling major bioactive compounds. The characterization of 28 components, including eleven flavonoids, thirteen triterpene acids, and four phenolic acids, was achieved on the basis of their maximum ultraviolet wavelength values and MS fragmentation pathways. An HPLC-evaporate light scattering detector (HPLC-ELSD) method over 35 min of analysis time for quality control of SF leaves was proposed. Using response surface methodology based on a Box-Behnken design and Derringer's desirability function, the optimal conditions for extracting the main bioactive compounds in SF leaves were determined. The content of marker compounds within SF leaves decreased in the order asiatic acid > corosolic acid > betulinic acid > maslinic acid. The developed HPLC-ELSD method is appropriate for quality control testing of SF leaves.

Cytotoxic triterpene saponins from the mangrove Aegiceras corniculatum.

Using various chromatographic separations, sixteen compounds, including one new triterpene saponin named aegicoroside A (1), were isolated from the leaves of the Vietnamese mangrove Aegiceras corniculatum. Their structures were determined by spectroscopic methods such as 1D and 2D NMR and HR-ESI-MS. The cytotoxic activities of the isolated compounds against MCF7 (breast), HCT116 (colon), B16F10 (melanoma), and A549 (adenocarcinoma) cancer cell lines were also evaluated. Strong cytotoxicity was observed for sakurasosaponin (2) against all four cancer cell lines and for sakurasosaponin methyl ester (3) against MCF7, A549, and HCT116 cell lines with IC50 values ranging from 2.89 ± 0.02 to 9.86 ± 0.21 µM.

Improving the efficacy of type 1 diabetes therapy by transplantation of immunoisolated insulin-producing cells.

Type 1 diabetes occurs when pancreatic islet ß-cells are damaged and are thus unable to secrete insulin. Pancreas- or islet-grafting therapy offers highly efficient treatment but is limited by inadequate donor islets or pancreases for transplantation. Stem-cell therapy holds tremendous potential and promises to enhance treatment efficiency by overcoming the limitations of traditional therapies. In this study, we evaluated the efficiency of preclinical diabetic treatment. Diabetes was induced in mice by injections of streptozotocin. Mesenchymal stem cells (MSCs) were derived from mouse bone marrow or human umbilical cord blood and subsequently differentiated into insulin-producing cells. These insulin-producing cells were encapsulated in an alginate membrane to form capsules. Finally, these capsules were grafted into diabetic mice by intraperitoneal injection. Treatment efficiency was evaluated by monitoring body weight and blood glucose levels. Immune reactions after transplantation were monitored by counting total white blood cells. Allografting or xenografting of encapsulated insulin-producing cells (IPCs) reduced blood glucose levels and increased body weight following transplantation. Encapsulation with alginate conferred immune isolation and prevented graft rejection. These results provide further evidence supporting the use of allogeneic or xenogeneic MSCs obtained from bone marrow or umbilical cord blood for treating type 1 diabetes.

Production of functional dendritic cells from menstrual blood--a new dendritic cell source for immune therapy.

Dendritic cells (DCs) are the most professional antigen-presenting cells of the mammalian immune system. They are able to phagocytize, process antigen materials, and then present them to the surface of other cells including T lymphocytes in the immune system. These capabilities make DC therapy become a novel and promising immune-therapeutic approach for cancer treatment as well as for cancer vaccination. Many trials of DC therapy to treat cancers have been performed and have shown their application value. They involve harvesting monocytes or hematopoietic stem cells from a patient and processing them in the laboratory to produce DCs and then reintroduced into a patient in order to activate the immune system. DCs were successfully produced from peripheral, umbilical cord blood-derived monocytes or hematopoietic stem cells. In this research, we produced DCs from human menstrual blood-derived monocytes. Briefly, monocytes were isolated by FACS based on FSC vs. SSC plot from lysed menstrual blood. Obtained monocytes were induced into DCs by a two-step protocol. In the first step, monocytes were incubated in RPMI medium supplemented with 2% FBS, GM-CSF, and IL-4, followed by incubation in RPMI medium supplemented with α-TNF in the second step. Our data showed that induced monocytes had typical morphology of DCs, expressed HLA-DR, HLA-ABC, CD80 and CD86 markers, exhibited uptake of dextran-FITC, stimulated allogenic T cell proliferation, and released IL-12. These results demonstrated that menstrual blood can not only be a source of stromal stem cell but also DCs, which are a potential candidate for immune therapy.