• KSBB Journal
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• v.23 no.2
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• pp.164-168
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• 2008

The purpose of this study was to confirm the content of total polyphenol, antioxidative and immune activities of the extracts of Cedrela sinensis leaf. The content of total polyphenol of water extracts ranged from 46.5-59.6 mg/100 g, which was higher than other extracts using organic solvents such as EtOAc, $CH_2Cl_2$ and $C_6H_{14}$. The antioxidant activity of the water and organic solvents extracts showed 6-33% in terms of 2,2-diphenyl-picryl-hydrazyl (DPPH) scavenging activity. To analyze the immuno-stimulation activity of C. sinensis leaf extract, we investigated the effect of the extracts on NO synthesis which is important in host defense against bacterial infection. Hot water extracts significantly increased NO generation by RAW 264.7, macrophage cell line, while organic solvent extract has no significant effect on NO production. To further analyzed the anti-inflammatory effect of the extracts, we investigated the effects of the extracts on lipopolysaccharide(LPS)-induced NO generation. Organic solvent extracts of C. sinensis leaves showed strong inhibitory effect on NO production in LPS-stimulated RAW 264.7 cells. These results suggest that C. sinensis leaf extract may represent a useful immune stimulating agent and anti-inflammatory agent.

• Journal of radiological science and technology
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• v.40 no.1
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• pp.135-142
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• 2017

Selenium (Se), which is natural materials existing was known as an important component of selenoprotein, one of the important proteins responsible for the redox pump of a living body. Selenium was orally administered to Rat and irradiated with 10 Gy of radiation. Then, the thyroid gland was used as a target organ for 1 day, 7 days and 21 days to investigate the radiation protection effect of selenium (Se) through changes of blood components, thyroid hormones (T3, T4), antioxidant enzyme (GPx) activity and thyroid tissue changes. As a result, there was a significant protective effect of hematopoietic immune system(hemoglobin concentration, neutrophil, platelet)(p<0.05). The activity of Glutathione Peroxidase (GPx), the antioxidant enzyme, and the activity of the target organ, thyroid hormone (T3, T4), also showed significant activity changes (p<0.05). In the observation of tissue changes, it was confirmed that there was a protective effect of thyroid cell damage which caused the cell necrosis by radiation treatment. Therefore, it is considered that selenium(Se) can be utilized as a radiation defense agent by inducing immunogenic activity effect of a living body.

• Food Science and Preservation
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• v.21 no.1
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• pp.46-54
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• 2014

Yellow and black soybean Cheonggukjangs (YBSC) prepared with an addition of onion (Allium cepa L.) in different contents (0, 5, 10, 20, and 30%, w/w) were manufactured, and the sensory evaluation was carried out. The optimum addition ratio of onion was determined to be 20%. Total phenolic and flavonoid contents of YBSC prepared with an addition of onion were higher than those of the YBSC prepared without an onion. In addition, YBSC prepared with an addition of onion showed higher 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activities than those prepared without an onion. Furthermore, rat blood plasma 1 hour after oral administration of YBSC prepared with an onion was more effective in suppressing the accumulation of cholesteryl ester hydroperoxide than those prepared without onion and control. These results indicated that the consumption of the YBSC prepared with onion may contribute to the antioxidant defense in vivo.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.1
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• pp.1-8
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• 2014

In this study, we investigated the protective effects of green tea seed extract (GSE) against UVB-induced skin damage in human skin fibroblasts. GSE was first analyzed for antioxidant activity using 1,1-diphenyl-2picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging assays. Treatment of UV-irradiated fibroblast with GSE at 10~50 ${\mu}g/mL$ significantly increased DPPH and ABTS radical scavenging activities in a dose-dependent manner. GSE treatment inhibited matrix metalloproteinase (MMP-1, MMP-3, and MMP-9) expression and MMP-1 secretion caused by UVB irradiation. Moreover, treatment with GSE significantly increased type-1 collagen expression and production. We next examined levels of antioxidative enzymes (SOD, catalase, and GPx). Reduced antioxidative enzyme activities caused by UVB irradiation were recovered by treatment with GSE at 30 ${\mu}g/mL$ and 50 ${\mu}g/mL$. In conclusion, these results show that GSE has protective effects against UVB-induced skin damage in human skin fibroblasts by regulating antioxidative defense systems and MMP expression.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.493-497
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• 2012

The objective of this study was carried out in order to evaluate the antioxidative activities of n-hexane fractions from medicinal herbs. Certain parts from 6 species of edible and medicinal herbs were extracted with methanol. Radical scavenging activity of the n-hexane fractions against DPPH and ABTS radicals were observed to be high in Psoralea corylifolia, and Scutellsria barbata; it also significantly increased (p<0.05). For a comparison of the effect of various concentration of fractions, as the concentration of treatment increased, the antioxidative effects on radical scavenging activity also oncreased; yet it was not significant. The antioxidative effect of medicinal plants was dependent on the concentration but was not significant. Therefore, these results indicate that edible wild plants, such as Psoralea corylifolia, and Scutellsria barbata may be useful as potential antioxidant sources for improving the human antioxidant defense system against disease.

• Current Research on Agriculture and Life Sciences
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• v.16
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• pp.24-30
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• 1998

This experiment was carried out to elucidate and study about plant defense mechanism subjected to water stress(drought, flooding). We measured water content, total soluble protein content as stress marker and superoxide dismutase(SOD), catalase (CAT) as antioxidant enzymes subjected to water stress(drought, flooding) and recovery in soybean leaves. The results obtained were as follows; Two soybean lines(keonolkong, euhakong)leaves exposed to water stress (drought, flooding) showed premature senescence as evidence by the decrease in water content, and total soluble protein content, but those of soybean leaves subject to water stress recovery for 3 days were recovered. Visual damage was much worse at drought stress than flooding stress and was worse keunolkong than enhakong. The activity of superoxide dismutase, catalase subjected to water stress(drought, flooding)was on the decrease, but degree of decrease was different from a sort of soybean lines, drought and flooding stress.

• Journal of Marine Life Science
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• v.3 no.2
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• pp.74-80
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• 2018

Mercury (Hg) poses a threat to marine ecosystem due to continuous inflow from various industries and bioaccumulation to higher trophic level via food web. Mercury can adversely affect growth, development, reproduction and metabolism to aquatic organisms. In the present study, acute toxicity and oxidative stress markers (total glutathione content, and activities of GST, GR and GPx) were investigated in brackish water flea Disphanosoma celebensis exposed to HgCl₂ for 24 h. As results, Hg showed negative effect in survival of D. celebensis. 24 h-LC₅₀ value was determined as 0.589 mg/l (95% C.I. 0.521~0.655 mg/l). After exposure to Hg (0.08 and 0.4 mg/l) for 24 h, total glutathione content was significantly decreased, whereas GST, GPx and GR activities were enhanced. These findings indicate that Hg induced oxidative stress in D. celebensis, and oxidative stress markers may be involved in cellular defense against Hg - mediated toxicity. This study provides a better understanding of molecular mode of action of Hg toxicity in this specie and potent of molecular markers for heavy metal monitoring in marine ecosystem.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1310-1317
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• 2003

Effects of dietary cholesterol and/or taurine supplementation on plasma and hepatic lipid peroxidation status and antioxidant enzyme activities were evaluated in rats fed one of the following semisynthetic diets for 5 weeks: control diet (CD, cholesterol-free and taurine-free diet); high cholesterol diet (HCD, CD+1.5% cholesterol): high taurine diet (HTD, CD+1.5% taurine): high cholesterol and high taurine diet (HCHTD, HCD + 1.5% taurine). Plasma malondialdehyde (MDA) level was not influenced by dietary cholesterol or taurine supplementation, while hepatic MDA level was 70% higher in rats fed HCD compared to the value for CD rats (p<0.05). Our observation that taurine supplementation significantly decreased the hepatic MDA level of rats fed HCD, but failed to decrease lipid peroxidation of rats fed CD indicates that the protective effect of taurine in the liver against lipid peroxidation is manifested only under the hypercholesterolemic environment. Plasma and hepatic glutathione peroxidase (GSH-Px) activities were not affected by dietary supplementation of cholesterol or taurine. However, hepatic superoxide dismutase (SOD) activity was significantly reduced by dietary taurine supplementation (p <0.05), and thus significantly lower in rats fed HTD compared to the value for CD (p<0.05). Plasma total cholesterol concentration was positively correlated with hepatic cholesterol concentration as expected (r=0.712, p<0.001). Plasma (r=0.399, p<0.05) and hepatic cholesterol levels (r=0.429, p<0.05) showed a significantly positive correlation with hepatic MDA concentration, respectively. Plasma taurine concentration was negatively correlated with hepatic SOD activity (r=-0.481, p<0.01), and tended to be negatively correlated with hepatic GSH-Px activity without showing statistical significance (r=-0.188, p<0.05). These results indicate an antioxidative effect of taurine in rats with elevated level of lipid Peroxidation due to high intake of dietary cholesterol. Future application of taurine as a safe candidate for a hypolipidemic agent without adversely affecting body's antioxidant defense system is speculated.

• Korean Journal of Plant Resources
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• v.22 no.4
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• pp.330-336
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• 2009

The purpose of this study is to know the effect of wood vinegar ingestion on antioxidative defense system in trained rats. Twenty-eight male Sprague-Dawley male rats were used as the subject. Experimental groups were divided into CON-SED(control + sedentary), CON-EX(control + exercise), WV-SED(wood vinegar ingestion + sedentary), and WV-EX(wood vinegar ingestion + exercise), respectively. Body weight and stored fat weight(mesentery, retroperitoneal and epididymal) were not significantly differed in each group. Concentration of TG and FFA was not differed by wood vinegar ingestion. Concentration of glucose was revealed significant difference in exercise group rather than sedentary group, but there was no difference by wood vinegar ingestion between the groups. Contents of SOD in WV-EX group was significantly higher than other three groups. Contents of MDA in CON-EX group was significantly lower than CON-SED group, while the difference between CON group and WV group was not observed. In conclusion, wood vinegar ingestion with exercise seems to have a positive beneficial effects on reducing oxidative stress.

• Tribology and Lubricants
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• v.34 no.5
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• pp.197-207
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• 2018

Thermal deterioration of fuel due to long-term storage influences engine performance and causes malfunctions. Fuel stability is usually evaluated via heat resistance and thermal stability during a brief heat shock at high temperature; storage stability in this scenario means that there is very little change in the quality of the fuel during long-term storage. In addition, rubber-based products such as oil seals, O-rings, and rubber hoses can influence the quality of the fuel. When these rubber products are in contact with fuel, they can swell, mechanically weaken, and occasionally crack, thus leaking low molar weight rubber and additives including plasticizer and antioxidant into the fuel to degrade its properties and shorten its useful lifetime. This study determines the thermal stabilities of three kinds of synthetic fuels by evaluating their low temperature kinematic viscosities, chemical composition changes via GC analyses, gross heat of combustion, and color changes. We evaluate the compression set of O-rings by immersing one NBR and two FKM rubber O-rings in the three synthetic fuel samples in airtight containers at variable storage temperatures for six months; from this, we estimate the lifetimes of the O-rings using the Power law model. There were very little changes in the chemical compositions and gross heat of combustion after six months of the experiment. The lifetimes are thus dependent on the materials of the rubber products, and in particular, the FKM O-ring was calculated to have a theoretical lifetime of 200 to 5,700 years. These results indicate that the synthetic fuels maintain their physical properties even after long-term storage at high temperatures, and the FKM O-ring is suitable for long-term sealing of these fuels.