Chemical activation of porous/nonporous materials to achieve high surface area sorbents with enhanced textural properties is a very promising strategy. The chemical activation using KOH, however, could lead to broad distribution of pores originating from the simultaneous pore deepening and widening pathways. Accordingly, establishing correlation between the chemical/textural properties of starting porous/nonporous materials and various pore formation mechanisms is quite critical to realize superior porosity and gas uptake properties. Here, we show that the chemical and textural properties of starting porous organic polymers, that is, covalent triazine frameworks (CTF), have profound effect on the resulting porosity of the frameworks. The chemical activation of microporous CTF-1 using KOH at 700 °C enabled the preparation of chemically activated CTF-1, caCTF-1-700, which predominantly showed pore deepening, leading to an increased surface area of 2367 m g and significantly enhanced gas adsorption properties with CO uptake capacities up to 6.0 mmol g at 1 bar and 1.45 mmol g at 0.15 bar and 273 K along with a isosteric heats of adsorption (Q) of 30.6 kJ mol. In addition, a remarkable H uptake capacity of 2.46 and 1.66 wt % at 77 and 87 K, 1 bar along with the Q value of 10.95 kJ mol at zero coverage was also observed for the caCTF-1-700. Notably, the activation of mesoporous CTF-2 under the same conditions was accompanied by a decrease in its surface area and also in the conversion of mesopores into the micropores, thus leading to a pore deepening/narrowing rather than widening. We attributed this result to the presence of reactive weak spots, triazine moieties, for the chemical activation reaction within the CTF backbone. These results collectively suggest the critical role of chemical and pore characteristics of porous organic polymers in chemical activation to realize solid-sorbents for high capacity gas storage applications.
Decursin, a bioactive phytochemical isolated from Angelica gigas Nakai (danggwi), has shown preclinical anticancer efficacy in various cancer models. However, the antitumor effect of decursin in melanoma models remains undefined. The antitumor activities of decursin were investigated in B16F10 cells in vitro and in vivo. In this study, we show that treatment with decursin inhibited cell proliferation in a dose-dependent manner in B16F10 cells, but not in normal cells. Decursin also induced apoptosis in B16F10 cells, as determined by annexin V-staining assay and transferase-mediated nick-end labeling (TUNEL) staining assay. Decursin increased the phosphorylation of p38 as well as the expression of Bax while decreasing the phosphorylation of extracellular signaling-regulated kinase (ERK) and the expression of Bcl-2 in B16F10 cells. Moreover, decursin activated caspase-3 in B16F10 cells and xenograft tumor tissue. Together, these findings support further investigations into the potential use of decursin in the treatment of melanoma cells.
Four Lactobacillus strains - Lactobacillus plantarum CJLP133, L. plantarum CJLP243, L. plantarum CJNR26, and Lactobacillus gasseri CJMF3 - were isolated from Korean fermented food or healthy infant feces, and their capacity to modulate cellular and humoral immune responses was studied. Feeding of the tested lactobacilli for 8 weeks did not alter the weight of and cell numbers in the spleen of mice. However, CJLP133 and CJLP243 strains increased the T lymphocyte population in the spleen of mice, while CJNR26 and CJMF3 increased the B lymphocyte population. In splenocytes treated with concanavalin A, ingestion of CJLP133 and CJLP243 promoted T lymphocyte proliferation and secretion of T cell cytokines, whereas feeding of the CJNR26 and CJMF3 strains enhanced B lymphocyte proliferation in splenocytes treated with lipopolysaccharide and plaque formation. These results suggest that CJLP133 and CJLP243 have immunostimulating activity through the enhancement of T cell activation, while CJNR26 and CJMF3 exhibit immunopotentiation through the increment of B cell activation.
BackgroundHeat treatments are applied to ginseng products in order to improve physiological activities through the conversion of ginsenosides, which are key bioactive components. During heat treatment, organic acids can affect ginsenoside conversion. Therefore, the influence of organic acids during heat treatment should be considered.MethodsRaw ginseng, crude saponin, and ginsenoside Rb1 standard with different organic acids were treated at 130°C, and the chemical components, including ginsenosides and organic acids, were analyzed.ResultsThe organic acid content in raw ginseng was 5.55%. Organic acids were not detected in crude saponin that was not subjected to heat treatment, whereas organic acids were found in crude saponin subjected to heat treatment. Major ginsenosides (Rb1, Re, and Rg1) in ginseng and crude saponin were converted to minor ginsenosides at 130°C; the ginsenoside Rb1 standard was very stable in the absence of organic acids and was converted into minor ginsenosides in the presence of organic acids at high temperatures.ConclusionThe major factor affecting ginsenoside conversion was organic acids in ginseng. Therefore, the organic acid content as well as ginsenoside content and processing conditions should be considered important factors affecting the quality of ginseng products.
Recent studies have reported that the aerial parts of ginseng contain various saponins, which have anti-oxidative, anti-inflammatory, and anti-obesity properties similar to those of ginseng root. However, the leaf extracts of Korean ginseng have not yet been investigated. In this study, we demonstrate the anti-obesity effects of green leaf and dried leaf extracts (GL and DL, respectively) of ginseng in high-fat diet (HFD)-induced obese rats. The administration of GL and DL to HFD-induced obese rats significantly decreased body weight (by 96.5% and 96.7%, respectively), and epididymal and abdominal adipose tissue mass. Furthermore, DL inhibited the adipogenesis of 3T3-L1 adipocytes through regulation of the expression of key adipogenic regulators, such as peroxisome proliferator-activated receptor (PPAR)-γ and CCAAT/enhancer-binding protein (C/EBP)-α. In contrast, GL had little effect on the adipogenesis of 3T3-L1 adipocytes but greatly increased the protein expression of PPARγ compared with that in untreated cells. These results were not consistent with an anti-obesity effect in the animal model, which suggested that the anti-obesity effect of GL in vivo resulted from specific factors released by other organs, or from increased energy expenditure. To our knowledge, these findings are the first evidence for the anti-obesity effects of the leaf extracts of Korean ginseng in vivo.
Major histocompatibility complex (MHC) class I molecules present antigenic peptides to the cell surface for screening by CD8(+) T cells. A number of ER-resident chaperones assist the assembly of peptides onto MHC class I molecules, a process that can be divided into several steps. Early folding of the MHC class I heavy chain is followed by its association with beta(2)-microglobulin (beta(2)m). The MHC class I heavy chain-beta(2)m heterodimer is incorporated into the peptide-loading complex, leading to peptide loading, release of the peptide-filled MHC class I molecules from the peptide-loading complex, and exit of the complete MHC class I complex from the ER. Because proper antigen presentation is vital for normal immune responses, the assembly of MHC class I molecules requires tight regulation. Emerging evidence indicates that thiol-based redox regulation plays critical roles in MHC class I-restricted antigen processing and presentation, establishing an unexpected link between redox biology and antigen processing. We review the influences of redox regulation on antigen processing and presentation. Because redox signaling pathways are a rich source of validated drug targets, newly discovered redox biology-mediated mechanisms of antigen processing may facilitate the development of more selective and therapeutic drugs or vaccines against immune diseases.
Programmed death-1 (PD-1) is a co-inhibitory receptor of the CD28/CTLA-4 family which is expressed on activated T cells and inhibits T cell activation after binding to PD-1 ligands. In animal models, PD-1 regulates autoimmune disease and induces tolerance in pancreas. In this study the effects of PD-1 on type 1 diabetes were examined using PD-1 transgenic mice (Tg). The incidence of autoimmune diabetes induced by multiple low dose of streptozotocin (STZ) was reduced in PD-1 Tg mice. Although the expression of CTLA-4, PD-1 and FoxP3, which are inhibitory molecules of activated T cells, is reduced only on STZ injected wild type (WT) mice, CD4, CD8 and regulatory T cell populations were not changed in all experimental groups. When splenocytes were re-stimulated in ex vivo, the production of IL-2 and IFN-γ and the T cell proliferation were increased in all STZ injected mice, but the increment rate was less in PD-1 Tg groups. Interestingly, macrophages were observed in splenocytes of STZ injected PD-1 Tg at somewhat lower level than macrophage in diabetic wild type mice. In this research, we found out that total numbers of T cell in the experimental groups are not changed, but T cell function is changed, and FoxP3 expression is decreased in pancreas and spleen of diabetes-induced groups. Macrophage frequency might also affects on type 1 diabetes. Although more experimental evidence needs to be provided, these results suggest that ligation of PD-1 and PD-L1/2 may have an effect on macrophages as well as does T cells.
This study investigated the changes in the functional components of three cultivars (Kunalbori, Dahan, and Hinchalssalbori) over a 6 day germination period; these cultivars were selected because of their varied characteristics and applications. Barley produced from the cultivars was subjected to 6 days of germination. Germinated barley was analyzed for total polyphenol, total flavonoid, hordenine, total arabinoxylan, soluble arabinoxylan, γ‐aminobutyric acid, and γ‐oryzanol contents. The total polyphenol content increased with germination period, corresponding to 1.47–3.83, 1.41–3.42, and 1.59–2.82 mg/g in barley produced from the three cultivars, respectively. The corresponding total flavonoid contents were 0.35–0.44, 0.31–0.48, and 0.22–0.37 mg/g. The hordenine contents in the barley produced from the three cultivars increased from not detected for nongerminated barley to 1.52, 1.09, and 1.34 mg/100 g, respectively, at germination day 6. The γ‐aminobutyric acid content significantly increased until germination day 4, followed by a decrease, and the highest content was observed for barley produced from the Kunalbori cultivar at germination day 4. The total arabinoxylan and soluble arabinoxylan contents increased with germination period. Results indicated that the germination period is crucial for increasing the functional components. These results are expected to be beneficial during food product manufacturing.
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