• Corrosion Science and Technology
• /
• v.20 no.4
• /
• pp.175-182
• /
• 2021

Magnesium alloy is limited in the industrial field because its standard electrode potential is -2.363 V vs. NHE (Normal Hydrogen Electrode) at 25 ℃. This high electrochemical activity causes magnesium to quickly corrode with oxygen in air; chemical conversion coating prevents corrosion but causes surface defects like cracks and pores. We have examined the anti-corrosion effect of sol-gel coating sealed on the defected conversion coating layer. Sol-gel coatings produced higher voltage current and smaller pore than the chemical conversion coating layer. The conversion coating on magnesium alloy AZ31 was prepared using phosphate-permanganate solution. The sol-gel coating was designed using trimethoxymethylsilane (MTMS) and (3-Glycidyloxypropyl) trimethoxysilane (GPTMS) as precursors, and aluminum acetylacetonate as a ring-opening agent. The thermal shock resistance was tested by exposing specimens at 140 ℃ in a convection oven; the results showed changes in the magnesium alloy AZ31 surface, such as oxidization and cracking. Scanning electron microscope (FE-SEM) analysis confirmed a sealed sol-gel coating layer on magnesium alloy AZ31. Electrochemical impedance spectroscopy (EIS) measured the differences in corrosion protection properties by sol-gel and conversion coatings in 0.35 wt% NaCl solution, and the potentiodynamic polarization test and confirmed conversion coating with the sol-gel coating show significantly improved resistance by crack sealing.

• IMMUNE NETWORK
• /
• v.4 no.1
• /
• pp.7-15
• /
• 2004

Background: The heat shock proteins (HSPs) play an important role in cellular protection mechanisms against physical or chemical stresses. In this study scFv antibodies specific for human HSP70.1 were isolated from a semi-synthetic human scFv library with the ultimate goal of developing anti-HSP70.1 intracellular antibody (intrabody) that may offer an attractive alternative to gene targeting to study the function of the protein in cells. Methods: A semi-synthetic human scFv display library ($5{\times}10^{8}$ size) was constructed using pCANTAB-5E vector and the selection of the library against bacterially expressed recombinant human HSP70.1 was attempted by panning. Results: Three positive clones specific for recombinant HSP70.1 were identified. All three clones used $V_{H}$ subgroup III. On the other hand, $V_{L}$ of two clones belonged to the kappa light chain subgroup I, but the other utilized $V_{k}$ subgroup IV Interestingly, these scFv molecules specifically reacted to the recombinant HSP70.1, yet failed to recognize native HSP70 induced in U937 human monocytic cells by heat treatment. Conclusion: Our results indicated that affinity selection of an scFv phage display library using recombinant antigens produced in E. coli might not guarantee the isolation of scFv antibody molecules specific for a native form of the antigen. Therefore, the source of target antigens needs to be chosen carefully in order to isolate biofunctional antibody molecules.

• Journal of Ginseng Research
• /
• v.36 no.3
• /
• pp.263-269
• /
• 2012

Korean red ginseng has shown therapeutic effects for a number of disease conditions. However, little is known about the anti-inflammatory effect of Korean red ginseng saponin fraction (RGSF) in vitro and in vivo. Therefore, in this study, we showed that RGSF containing 20(S)-protopanaxadiol type saponins inhibited nitric oxide production and attenuated the release of tumor necrotic factor (TNF)-${\alpha}$, interleukin (IL)-6, granulocyte monocyte colony stimulating factor (GMCSF), and macrophage chemo-attractant protein-1 in lipopolysaccharide (LPS) stimulated murine macrophage RAW264.7 cells. Moreover, RGSF down-regulated the mRNA expressions of inducible nitric oxide synthase, cyclooxyginase-2, IL-$1{\beta}$, TNF-${\alpha}$, GMCSF, and IL-6. Furthermore, RGSF reduced the level of TNF-${\alpha}$ in the serum and protected mice against LPS mediated endotoxic shock. In conclusion, these results indicated that ginsenosides from RGSF and their metabolites could be potential sources of therapeutic agents against inflammation.

• Pediatric Infection and Vaccine
• /
• v.24 no.2
• /
• pp.112-116
• /
• 2017

Kawasaki disease (KD) is an acute febrile mucocutaneous lymph node syndrome that commonly presents with stable hemodynamic status during the acute phase. An 8-year-old boy initially presented with severe hypotension and acute kidney injury. He was placed in the intensive care unit and was diagnosed with KD. Observed clinical features were defined as KD shock syndrome. His coronary artery was dilated during the subacute phase. Furthermore, he was given anti-hypertensive medications, owing to hypertension as an unusual complication of KD. We knew the importance of monitoring for blood pressure considering vasculitis as an aspect of the main pathogenesis of KD.

• Korean Journal of Plant Resources
• /
• v.22 no.5
• /
• pp.431-437
• /
• 2009

To investigate the anti-inflammatory effect of Ephedrae Herba in vivo and in vitro acute inflammation was induced by lipopolysaccharide (LPS) shock in rats fed Ephedrae Herba extracts and inflammatory cytokine concentrations were examined. In addition, the effect of Ephedrae Herba extracts on the production of inflammatory cytokines was examined in LPS-stimulated Raw 264.7 cells. In an in vivo experiment, plasma interleukin-$1{\beta}$ (IL-$1{\beta}$), interleukin-6 (IL-6), interleukin-10 (IL-10) and tumor necrosis factor-$\alpha$ (TNF-$\alpha$) concentrations were increased at 2 h and reached to maximal levels at 5 h after LPS treatment in all groups. Compared with control group, plasma IL-$1{\beta}$, IL-6, and TNF-$\alpha$ levels were lowered at 5 h after LPS treatment, but plasma IL-10 level was higher in at 2 and 5 h after LPS treatment in Ephedrae Herba extract group. In an in vitro experiment using Raw 264.7 macrophages, IL-$1{\beta}$, IL-6 and TNF-$\alpha$ concentrations in the Ephedrae Herba extract group were lower than those in control group. Compared with control group, IL-10 concentration appeared to be higher in the Ephedrae Herba extract group, but this trend was not significant. In conclusion, these results suggested that functional compound (s) in Ephedrae Herba extract may play a role in alleviating inflammatory response.

• Journal of Life Science
• /
• v.33 no.11
• /
• pp.876-886
• /
• 2023

In some cases of head and neck cancers (HNC), surgical interventions may result in the loss of organs and/or changes to their functions, thereby significantly affecting the patient's quality of life. As a result, the surgical treatment of HNC patients is often limited to specific cases, and alternative treatment modalities, such as chemotherapy, are considered. However, serious adverse effects caused by chemotherapy, such as severe nausea and vomiting, necessitate the need for the development of adjunctive methods to minimize patient suffering. Chuanxiong, Ligusticum chuanxiong (L. chuanxiong), is a natural herb used in Eastern medicine to treat cerebrovascular disorders and headaches. This study aimed to predict the effect and potential of L. chuanxiong as an auxiliary anticancer drug through network-based pharmacology and molecular docking analysis. The study results showed that 40 out of 41 genes of L. chuanxiong shared common targets of HNC and their proteins could be used to target HNC cells to prevent cancer progression. The results of the functional enrichment analysis confirmed that L. chuanxiong is associated with the neuroactive-ligand metabolism and neurotransmitter pathways, indicating its potential medicinal value as an adjuvant in HNC treatment. Lastly, our findings demonstrated that the active ingredient of L. chuanxiong, (Z)-Ligustilide, has the ATP binding site of heat shock protein 90, a protein known to promote the activation of cancer cells. These results suggest that L. chuanxiong is a promising candidate for developing auxiliary anticancer drugs, and further research could potentially lead to the discovery of newer and safer anti-cancer agents.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.30 no.4 s.48
• /
• pp.471-477
• /
• 2004

Exposure to elevated temperatures, chemical (active oxigen), or physical stress (UV light) induces immediate physiological response, the expression of heat shock proteins in cells. Thus, cells with elevated Heat Shock Protein levels become more tolerant to stress conditions that are otherwise lethal. First, we studied on the new function of glucuronic acid (GA) as preventive material of skin aging. The application of the GA shows significant induction of Heat Shock Protein 70 kDa (HSP 70 kDa) in contrast to cells without it. GA at the concentration which can induce HSP 70 kDa, protects the cell death induced by second stress (heat shock and hydrogen peroxide) in NIH3T3 cells. Second, we studied on in vitro transdermal permeation characteristic of GA through the excised mouse skin. In this study, we compared the skin permeability of GA in water with O/W emulsion. As a result, skin permeation parameters of GA shows lag time 1.2 h, partition coefficient 0.114, permeation flult rate $0.83114 mg/cm^2/h.$ In case of lag time, O/W emulsion containing GA increase 2.48 h. Also, the total accumulation permeation content decreased in contrast to GA solution after 24 h. But it has long-term permeability of glucuronic acid. These results suggest that glucuronic acid could be a good cosmetic active ingredient.

• Nutrition Research and Practice
• /
• v.8 no.5
• /
• pp.526-532
• /
• 2014

BACKGROUND/OBJECTIVES: Acanthopanax sessiliflorus is a native Korean plant and used as a traditional medicine or an ingredient in many Korean foods. The free radical theory of aging suggests that cellular oxidative stress caused by free radicals is the main cause of aging. Free radicals can be removed by cellular anti-oxidants. MATERIALS/METHODS: Here, we examined the anti-oxidant activity of Acanthopanax sessiliflorus extract both in vitro and in vivo. Survival of nematode C. elegans under stress conditions was also compared between control and Acanthopanax sessiliflorus extract-treated groups. Then, anti-aging effect of Acanthopanax sessiliflorus extract was monitored in C. elegans. RESULTS: Stem extract significantly reduced oxidative DNA damage in lymphocyte, which was not observed by leaves or root extract. Survival of C. elegans under oxidative-stress conditions was significantly enhanced by Acanthopanax sessiliflorus stem extract. In addition, Acanthopanax sessiliflorus stem increased resistance to other environmental stresses, including heat shock and ultraviolet irradiation. Treatment with Acanthopanax sessiliflorus stem extract significantly extended both mean and maximum lifespan in C. elegans. However, fertility was not affected by Acanthopanax sessiliflorus stem. CONCLUSION: Different parts of Acanthopanax sessiliflorus have different bioactivities and stem extract have strong anti-oxidant activity in both rat lymphocytes and C. elegans, and conferred a longevity phenotype without reduced reproduction in C. elegans, which provides conclusive evidence to support the free radical theory of aging.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.11
• /
• pp.3307-3312
• /
• 2014

The anti-inflammatory effect of a tubulin inhibitor, N-(5-benzyl-1,3-thiazol-2-yl)-3-(furan-2-yl)prop-2-enamide (1), on innate immune responses remains unclear. Thus, we investigated the effect of 1 on the immune responses mediated by lipopolysaccharide (LPS). The in vitro addition of 1 to dendritic cells and macrophages dose-dependently reduced tumor necrosis factor alpha production elicited by LPS stimulation. Additionally, the stimulation of natural killer (NK) and natural killer T (NKT) cells with 1 resulted in the decrease of interferon gamma ($IFN{\gamma}$) induced by LPS treatment. Moreover, 1 substantially reduced interleukin 12 in dendritic cells (DC) as well as $IFN{\gamma}$ in NKDCs induced by LPS in vitro. Furthermore, the in vivo administration of 1 ameliorated LPS/D-galactosamine-induced endotoxic lethality in mice. Taken together, our results demonstrate for the first time that 1 possesses anti-inflammatory properties, most notably by modulating LPS-induced innate immune responses. Therefore, 1 might have therapeutic potential for the treatment of inflammation-mediated diseases such as sepsis.

• BMB Reports
• /
• v.35 no.1
• /
• pp.116-126
• /
• 2002

Nitric oxide (NO), synthesized from L-arginine by NO synthases, is a small, lipophilic, diffusible, highly reactive molecule with dichotomous regulatory roles in many biological events under physiological and pathological conditions. NO can promote apoptosis (pro-apoptosis) in some cells, whereas it inhibits apoptosis (anti-apoptosis) in other cells. This complexity is a consequence of the rate of NO production and the interaction with biological molecules such as metal ion, thiol, protein tyrosine, and reactive oxygen species. Long-lasting overproduction of NO acts as a pro-apoptotic modulator, activating caspase family proteases through the release of mitochondrial cytochrome c into cytosol, up-regulation of the p53 expression, and alterations in the expression of apoptosis-associated proteins, including the Bcl-2 family. However, low or physiological concentrations of NO prevent cells from apoptosis that is induced by the trophic factor withdrawal, Fas, $TNF{\alpha}$/ActD, and LPS. The anti-apoptotic mechanism is understood on the basis of gene transcription of protective proteins. These include: heat shock protein, hemeoxygenase, or cyclooxygenase-2 and direct inhibition of the apoptotic executive effectors caspase family protease by S-nitrosylation of the cysteine thiol group in their catalytic site in a cell specific way. Our current understanding of the mechanisms by which NO exerts both pro- and anti-apototic action is discussed in this review article.