• The Korean Journal of Physiology and Pharmacology
• /
• v.8 no.2
• /
• pp.95-100
• /
• 2004

Ischemic preconditioning (IPC) has been accepted as a heart protection phenomenon against ischemia and reperfusion (I/R) injury. The activation of ATP-sensitive potassium $(K_{ATP})$ channels and the release of myocardial nitric oxide (NO) induced by IPC were demonstrated as the triggers or mediators of IPC. A common action mechanism of NO is a direct or indirect increase in tissue cGMP content. Furthermore, cGMP has also been shown to contribute cardiac protective effect to reduce heart I/R-induced infarction. The present investigation tested the hypothesis that $K_{ATP}$ channels attenuate DNA strand breaks and oxidative damage in an in vitro model of I/R utilizing rat ventricular myocytes. We estimated DNA strand breaks and oxidative damage by mean of single cell gel electrophoresis with endonuclease III cutting sites (comet assay). In the I/R model, the level of DNA damage increased massively. Preconditioning with a single 5-min anoxia, diazoxide $(100\;{\mu}M)$, SNAP $(300\;{\mu}M)$ and 8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphate (8-pCPT-cGMP) $(100\;{\mu}M)$ followed by 15 min reoxygenation reduced DNA damage level against subsequent 30 min anoxia and 60 min reoxygenation. These protective effects were blocked by the concomitant presence of glibenclamide $(50\;{\mu}M)$, 5-hydroxydecanoate (5-HD) $(100\;{\mu}M)$ and 8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphate, Rp-isomer (Rp-8-pCPT-cGMP) $(100\;{\mu}M)$. These results suggest that NO-cGMP-protein kinase G (PKG) pathway contributes to cardioprotective effect of $K_{ATP}$ channels in rat ventricular myocytes.

• Food Science and Biotechnology
• /
• v.16 no.2
• /
• pp.205-211
• /
• 2007

This study was designed to investigate the suppressive effect of chlorophyll a on nitric oxide (NO) production and intracellular oxidative stress. In addition, chlorophyll a regulation of nuclear factor (NF) ${\kappa}B$ activation and inducible NO synthase (iNOS) expression were explored as potential mechanisms of NO suppression in a lipopolysaccharide (LPS)-stimulated macrophage cell line. RAW 264.7 murine macrophages were preincubated with various concentrations ($0-10\;{\mu}g/ mL$) of chlorophyll a and stimulated with LPS to induce oxidative stress and inflammatory response. Treatment with chlorophyll a reduced the accumulation of thiobarbituric acid-reactive substances (TBARS), enhancing glutathione level and the activities of antioxidative enzymes including superoxide dismutase, catalase, glutathione peroxidase (GSH-px), and glutathione reductase in LPS-stimulated macrophages compared to LPS-only treated cells. NO production was significantly suppressed in a dose-dependent manner (p<0.05) with an $IC_{50}$ of $12.8\;{\mu}g/mL$. Treatment with chlorophyll a suppressed the levels of iNOS protein and its mRNA expression. The specific DNA binding activities of NFkB on nuclear extracts from chlorophyll a treated cells were significantly suppressed in a dose-dependent manner with an $IC_{50}$ of $10.7\;{\mu}g/mL$. Chlorophyll a ameliorates NO production and iNOS expression through the down-regulation of NFkB activity, which may be mediated by attenuated oxidative stress in RAW 264.7 macrophages.

• Preventive Nutrition and Food Science
• /
• v.12 no.4
• /
• pp.242-250
• /
• 2007

This study evaluated the storage stability of a variety of sauce products in the Korean market, determined primary quality indices for three typical products, and proposed functional relationships that are useful for determining shelf life at different temperatures. Most of the products examined were found to combine hurdles of low pH, low water activity, and the use of heat processing as methods for producing the required storage stability while maintaining the sensory quality of the products. For a meat extract solution produced for cold noodles (pH=4.3; $a_w=0.98$), the primary quality change determining shelf life was lipid oxidation, determined here by the TBA value. The primary quality index of a soybean paste seasoning mix (pH=4.0; $a_w=0.78$), which had a microbial load of 2.8 log (CFU/g), was a decrease in its pH. The primary quality index for a sandwich spread (pH=4.0; $a_w=0.88$) was changes in its surface color. The temperature dependence of changes in the primary quality indices can be described by the Arrhenius equation, which can estimate the shelf life at any arbitrary limit as a function of temperature. The activation energies for changes in the primary quality indices of the meat extract solution, the soybean paste seasoning, and the sandwich spread were 20.3, 27.2, and 43.5 kJ/mol, respectively.

• Biomolecules & Therapeutics
• /
• v.28 no.5
• /
• pp.465-472
• /
• 2020

Colorectal cancer (CRC) is one of the most malignant type of cancers and its incidence is steadily increasing, due to life style factors that include western diet. Abnormal activation of canonical Wnt/β-catenin signaling pathway plays an important role in colorectal carcinogenesis. Therefore, targeting Wnt/β-catenin signaling has been considered a crucial strategy in the discovery of small molecules for CRC. In the present study, we found that Nodosin, an ent-kaurene diterpenoid isolated from Isodon serra, effectively inhibits the proliferation of human colon cancer HCT116 cells. Mechanistically, Nodosin effectively inhibited the overactivated transcriptional activity of β-catenin/T-cell factor (TCF) determined by Wnt/β-catenin reporter gene assay in HEK293 and HCT116 cells. The expression of Wnt/β-catenin target genes such as Axin2, cyclin D1, and survivin were also suppressed by Nodosin in HCT116 cells. Further study revealed that a longer exposure of Nodosin induced the G₂/M phase cell cycle arrest and subsequently apoptosis in HCT116 cells. These findings suggest that the anti-proliferative activity of Nodosin in colorectal cancer cells might in part be associated with the regulation of Wnt/β-catenin signaling pathway.

• Biomolecules & Therapeutics
• /
• v.27 no.1
• /
• pp.92-100
• /
• 2019

Ginger, one of worldwide consumed dietary spice, is not only famous as food supplements, but also believed to exert a variety of remarkable pharmacological activity as herbal remedies. In this study, a ginger constituent, 12-dehydrogingerdione (DHGD) was proven that has comparable anti-inflammatory activity with positive control 6-shogaol in inhibiting LPS-induced interleukin (IL)-6, tumor necrosis factor $(TNF)-{\alpha}$, prostaglandin (PG) $E_2$, nitric oxide (NO), inducible NO synthase (iNOS) and cyclooxygenase (COX)-2, without interfering with COX-1 in cultured microglial cells. Subsequent mechanistic studies indicate that 12-DHGD may inhibit neuro-inflammation through suppressing the LPS-activated $Akt/IKK/NF-{\kappa}B$ pathway. Furthermore, 12-DHGD markedly promoted the activation of NF-E2-related factor (Nrf)-2 and heme oxygenase (HO)-1, and we demonstrated that the involvement of HO-1 on the production of pro-inflammatory mediators such as NO and $TNF-{\alpha}$ by using a HO-1 inhibitor, Zinc protoporphyrin (Znpp). These results indicate that 12-DHGD may protect against neuro-inflammation by inhibiting $Akt/IKK/I{\kappa}B/NF-{\kappa}B$ pathway and promoting Nrf-2/HO-1 pathway.

• Journal of the Korean Society of Radiology
• /
• v.14 no.5
• /
• pp.563-575
• /
• 2020

The purpose of this study is to evaluate the activation characteristics that occur in a linear accelerator for container security inspection. In the computer simulation design, first, the targets consisted of a tungsten (Z=74) single material target and a tungsten (Z=74) and copper (Z=29) composite target. Second, the fan beam collimator was composed of a single material of lead (Z=82) and a composite material of tungsten (Z-74) and lead (Z=82) depending on the material. Final, the concrete in the room where the linear accelerator was located contained magnetite type and impurities. In the research method, first, the optical neutron flux was calculated using the MCNP6 code as a F4 Tally for the linear accelerator and structure. Second, the photoneutron flux calculated from the MCNP6 code was applied to FISPACT-II to evaluate the activation product. Final, the decommissioning evaluation was conducted through the specific activity of the activation product. As a result, first, it was the most common in photoneutron targets, followed by a collimator and a concrete 10 cm deep. Second, activation products were produced as by-products of W-181 in tungsten targets and collimator, and Co-60, Ni-63, Cs-134, Eu-152, Eu-154 nuclides in impurity-containing concrete. Final, it was found that the tungsten target satisfies the permissible concentration for self-disposal after 90 days upon decommissioning. These results could be confirmed that the photoneutron yield and degree of activation at 9 MeV energy were insignificant. However, it is thought that W-181 generated from the tungsten target and collimator of the linear accelerator may affect the exposure when disassembled for repair. Therefore, this study presents basic data on the management of activated parts of a linear accelerator for container security inspection. In addition, When decommissioning the linear accelerator for container security inspection, it is expected that it can be used to prove the standard that permissible concentration of self-disposal.

• Food Science and Preservation
• /
• v.17 no.5
• /
• pp.571-580
• /
• 2010

We sought to define the main motivational factors promoting consumption of Prunus mume products. We surveyed both specialized high-volume consumers and public consumers, and focused on consumption of and preferences for Prunus mume and Prunus mume products. We investigated how products were preferentially consumed, purchase experience, purchase location, purchase price, consumption experience, factors important in a purchase decision, preference factors, dissatisfaction factors, consumption outlook, comments on new processed foods, and activation of consumption. A total of 534 responses were received and data were analyzed using the SAS program (Version 9.1) of the Frequency test; Chi-square test was used to detect significant factors. A greater percentage of high-volume(compared with low-volume) consumers processed personal products at home. The public consumer tended to buy commercial products. However, public consumers who were older, who had higher incomes, and who were heads of households, tended to both buy commercial products and to prepare foods at home. The common purchase methods used by high-volume consumers were internet and direct marketing, but the public consumer frequented department stores and hypermarkets. High-volume consumers observed that commercial products were expensive, and such consumers seemed to be particularly cost-sensitive. The decisive factor triggering purchase decisions in high-volume consumers was the geographical origin of the fruit, whereas the public consumer was more concerned with taste. In public, positive factors were that the product was good for health and had a pleasant taste. Some of those surveyed complained of a lack of variety in Prunus mume products and that the amount of Prunus mume in certain products was low. To promote and increase consumption, convenient-to-eat products with healthy images are needed.

• Environmental Mutagens and Carcinogens
• /
• v.22 no.3
• /
• pp.149-156
• /
• 2002

The detection of many synthetic chemicals used in industry that may pose a genetic hazard in our environment is of great concern at present. Since these substances are not limited to the original products, and enter the environment, they have become widespread environmental pollutants, thus leading to a variety of chemicals that possibly threaten the public health. In this respect, to regulate and to evaluate the chemical hazard will be important to environment and human health. The clastogenicity of 18 synthetic chemicals was evaluated in Chinese hamster lung fibroblast cells in vitro. 4-Chloro-3,5-dimethyl phenol (CAS No. 88-04-0) induced chromosomal aberrations with significance at the concentration of 15.7 $\mu\textrm{g}$/$m\ell$ both in the presence and absence of metabolic activation system. Phenoxybenzene (CAS No. 101-84-8) which is one of the most cytotoxic chemical among 18 chemicals tested revealed no clastogenicity in the range of 0.11-0.43 $\mu\textrm{g}$/$m\ell$ both in the presence and absence of metabolic activation system. From the results of chromosomal aberration assay with 18 synthetic chemicals in Chinese hamster lung cells in vitro, 4-chloro-3,5-dimethyl phenol (CAS No. 88-04-0) revealed weak positive clastogenic results in this study.

• Natural Product Sciences
• /
• v.16 no.4
• /
• pp.280-284
• /
• 2010

During liver fibrosis, hepatic stellate cells (HSCs) undergo a complex activation process characterized by increased proliferation and extracellular matrix deposition, which is the major pathological feature of hepatic cirrhosis. Therefore, suppression of HSCs activation has been proposed as therapeutic strategies for hepatic fibrosis. We tried to screen the antifibrotic activity of natural products employing HSC-T6, hepatic stellate cell lines as an in vitro assay system. In the present study, we investigated the antiproliferative activity of aerial parts and roots of Pulsatilla koreana Nakai (Ranunculaceae). Our present study shows that roots of P. koreana exerted more strong inhibitory activity compared to its aerial parts. In addition, among the fractions of the aqueous methanolic extract of P. koreana roots, both n-hexane and $CHCl_3$ fraction showed the strong inhibitory activity on HSC proliferation. Further study also demonstrated that the n-hexane and $CHCl_3$ fraction of P. koreana roots significantly inhibited the HSC proliferation in time- and concentration-related manners.

• Journal of the Korean Society of Safety
• /
• v.19 no.2
• /
• pp.47-53
• /
• 2004

Emulsion polymerization ws carried out using Alkyl methacrylate(RMA) like MMA, EMA, BMA and Styrene Monomer(SM) for core-shell latex preparation. It was synthesized at $80^{\circ}C$ in the presence of anionic surfactant SLS(Sodium Lauryl Sulfate). FT-IR and DSC analysis are used to confirm the synthesized core-shell emulsion latexes. Moreover DSC and TGA were used to investigate the thermal characterisitcs of them. The differences of the decomposition rate and the activation energy from TGA and DSC analysis are not so big. It considers that the pendent group is not affect of the thermal characteristics and stability on core-shell latexes, which is synthesized with RMA and Styrene. For investigating combustion products, LC50 values were calculated by FED(Fractional Effective Dose)from the Pyrolyzer-Mass sepctrometer.