• Journal of the Korean Electrochemical Society
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• v.2 no.1
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• pp.31-37
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• 1999

Copper-containig enzyme, laccase (Rhus vernicifera) was immobilized onto gold electrode using self-assembly technique and its surface properties and catalytic activities were examined. Laccase is an oxidoreductase capable to oxidize diphenols or diamines by 4-electron reduction of molecular oxygen without superoxide or peroxide intermediates. The electrode surface were modified by $\beta-mercaptopropionate$ to have a net negative charge in neutral solution and positively charged laccase (pI=9) was immobilized by electrostatic interaction. The successful immobilization was confirmed by cyclic voltammograms which showed typical surface-confined shapes and behaviors. The amount of charge to reduce the surface was similar to the charge calculated assuming the surface being covered by monolayer. The activity of the immobilized enzyme was tested by the capbility of oxidizing a substrate, ABTS (2,2-azine-bis-(3-ethylbenzthioline-6-sulfonic acid) and it was maintained for $2\~3$ days at $4^{\circ}C$. The immobilzed laccase showed about $10\~15\%$ activity compared to that in solution. The laccase-modified electrode showed the activity of elefoocatalytic reduction of oxygen in the presence of mediator, $Fe(CN)_6^{3-}$ The addtion of azide which is an inhibitor of laccase compeletly eliminated the catalytic current.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.5
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• pp.697-704
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• 2013

The inhibitory effect of ethanol extracts from Curdrania tricuspidata leaves (CTL) on osteoarthritis was investigated in primary cultured rat cartilage cells and a monosodium-iodoacetate (MIA)-induced arthritis rat model. To identify the effects of CTL 80% ethanol extracts (CTL80) and CTL 10% ethanol extracts (CTL10) against $H_2O_2$ treatment in vitro, cell survival was measured by the MTT assay. Cell survival after $H_2O_2$ treatment increased with CTL80 and CTL10 close to normal up to $300{\mu}g/mL\;H_2O_2$. The mRNA expression of matrix metalloproteinases (MMPs) was determined MMP-7 and MMP-13 (known catabolic factors), were significantly inhibited by CTL 80 and CTL10; a $200{\mu}g/mL$ dose of CTL80 especially decreased MMP-13 expression. In vivo, osteoarthritis was induced by an intra-articular injection of MIA into the knee joints of rats, then CTL80 and CTL10 orally administered daily for 35 days. After the animals were sacrificed, histological evaluations of their knee joints revealed a reduction in polymorphonuclear cell infiltration and smooth synovial lining in the CTL80-500 group. Micro-CT analysis of hind paws from CTL80-500 and CTL10 showed a protection against osteophyte formation, soft tissue swelling, and bone resorption. In conclusion, CTL ethanol extracts are effective in ameliorating joint destruction and cartilage erosion in MIA-induced rats. CTL decreases and normalizes articular cartilage through preventing extracellular matrix degradation and chondrocyte injury, and could potentially serve as a therapeutic treatment for humans.

• Journal of Life Science
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• v.29 no.11
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• pp.1273-1280
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• 2019

Age-related macular degeneration (AMD) is one of the leading causes of blindness in the elderly population, and damage to retinal pigment epithelial (RPE) cells due to oxidative stress contributes to the development of AMD. Glycyrrhiza uralensis Fischer is one of the most widely used herbal medicines for the treatment of various diseases in Asian countries. Although recent studies indicated that treatment with G. uralensis can protect cells from oxidative stress, its mechanisms in RPE cells remain unknown. We evaluated the effect of a G. uralensis ethanol extract (GU) on $H_2O_2$-induced oxidative injury in ARPE-19 RPE cells. The GU pretreatment attenuated reactive oxygen species (ROS) generation induced by $H_2O_2$, which was associated with induced expression of nuclear factor erythroid-derived-2-like 2 (Nrf2) and heme oxygenase-1 (HO-1). GU also suppressed $H_2O_2$-induced DNA damage and mitochondrial dysfunction. The inhibitory effect of GU on $H_2O_2$-induced apoptosis was associated with the protection of caspase-3 activation. Overall, GU appeared to protect RPE cells from oxidative injury by inhibiting DNA damage and reducing apoptosis. Further studies are needed to determine the regulation of Nrf2-mediated HO-1 expression, but our results suggest the possibility of using GU to reduce the risk of AMD.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.2
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• pp.181-188
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• 1989

The present study has been carried out to investigate the effect of Bactokil(made from didecyldimethyl ammonium chloride isopropanol and water) and Taipet-F (made from natural vitamin E, L-ascorbic acid, glyceride and gallic acid) on retarding lipid oxidation in boiled-dried anchovy. To process boiled-dried anchovy, boiled anchovy dried in cabinet drier $(dry-bulb\;temperature\;40^{\circ}C)$ for 1 hour were fronted with the Bactokil, the Taipet-F and mixture of Bactokil and Taipet-F, respectively. Anchovy fronted with chemicals were redried for 8 hours, packed in polyethylene film bag, and then stored at room temperature $(24{\pm}3^{\circ}C)$. These products were compared with control(untreated with chemicals) during storage. The changes in volatile basic nitrogen of each product was negligible during storage. The thiobarbituric acid and peroxide values of each product increased up to 10 days of storage, and then decreased. In color value of each product, L value increased, while n, b and ${\bigtriangleup}E$ values decreased during storage. The changes in brown pigment formation of each product increased up to final stage of storage. From the results of chemical analysis and sensory evaluation, the product treated with Taipet-F(0.5%, v/v) was the most effective on retarding lipid oxidation of the boiled -dried anchovy, followed by the product treated withthe mixture of Bactokil (0.04%, v/v) and Taipet-F (0.5%, v/v), the product treated with Bactokil(0.04%, v/v) and control, in the order named.

• Food Science and Preservation
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• v.31 no.4
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• pp.612-622
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• 2024

We examined the physicochemical properties and microbial safety of Enoki mushrooms during storage at 5℃ for 9 weeks, with different packaging containers that are corrugated, Al-coated, and without packaging (control). The weight change of Enoki mushrooms in the different containers due to moisture loss was 1.9%, 0.9%, 0.6% for control, corrugated, and Al-coated packaging, respectively. The degree of browning rapidly increased as the storage period increased in the control sample. However, corrugated and Al-coated packaging suppressed the browning degree. The changes of color L-, a-, and b-vlaues were minimal changes in Al-coated packaging. There was no significant difference in the total amino acids, polyphenol oxidase, and peroxidase in corrugated packaging and Al-coated packaging, regardless of the storage period. The microbial growth such as total aerobic bacteria, yeast, and mold of Enoki mushroom during the storage period, were significantly suppressed in Al-coated packaging samples as compared to the control and corrugated packaging. In conclusion, Al-coated packaging has beneficial effects such as preventing moisture loss, maintaining browning degree, inhibiting oxidative enzyme reaction, and ensuring microbial safety of Enoki mushrooms during the storage period. Al-coated packaging is considered effective for extending the shelf-life and improving the storage and distribution of mushrooms.

• Korean Journal of Medicinal Crop Science
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• v.11 no.1
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• pp.13-18
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• 2003

The biological activities of extracts from Rosa rugosae Radix were compared. About 78% of the growth of human hepato- carcinoma and 68% of human gastric cancer cell was inhibited in adding 0.5 mg/ml of the extracts of Rosa rugosae Radix respectively. The growth of human breast cancer cells was also inhibited in adding 0.5 mg/ml of the extracts as well as 66% of the human cancer cells. It was proved that the growth of human normal lung cell, scored as 20% for the extracts. Overall selectivity of the extracts on several human cancer cell line was over 4, which is higher than those from the Rosa rugosae Radix. The growth of both human immune B and T cells was enhanced up to 1.2 to 1.5 times by adding the extracts, compared to the controls. The secretion of tumor necrosis factor-alpha$(TNF-{\alpha})$ from T cell was also increased up to 61.9 pg/ml in adding the ethanol extract (0.5 mg/ml). Ethanol extract also increased up to about 61.3 pg/ml of interleukin-6(IL-6) from B cell.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.10
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• pp.1536-1544
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• 2005

We have investigated physiological effects of soy ice cream with oligosaccharide on oxidative stress and fecal microflora in streptozotocin-induced diabetic rats. Parched soybean powder (7.6$\%$, w/w) substituted skimmed milk and cream, soybean oil (7.6$\%$, w/w) for milk oil, and fructooligosaccharide (9.5$\%$, w/w) for sucrose. Five types of ice cream were prepared: regular, oligosaccharide-supplemented regular, soy, oligosaccharide - supplemented soy, and oligosaccharide - supplemented black soybean ice cream . Freeze - dried ice cream was supplemented to AIN93-based diets at 30$\%$ (w/w) containing 6.5$\%$ soy and 4.5$\%$ fructooligosaccharide. Diabetes was induced by intramuscular administration of streptozotocin, and experimental diets were given for 4 weeks. Plasma concentration of thiobarbituric acid reactive substances (TBARS) was significantly increased in the diabetic rats compared with the normal rats, then was significantly decreased with feeding soy ice cream containing diet compared with regular ice cream containing diet among the diabetic groups. The levels of TBARS in liver were decreased in the rats that were fed either soy or oligosaccharide ice cream compared with the rats that were fed regular ice cream. Erythrocyte superoxide dismutase activity was significantly increased in the rats fed soy ice cream compared with the rats fed regular ice cream. Erythrocyte glutathione peroxidase and catalase activities were significantly increased in the rats fed black soybean ice cream. Fecal concentrations of Lactobacilli were significantly higher in the rats fed soy ice cream and oligosaccharide- supplemented soy ice cream than that of the rats fed regular ice cream. Fecal concentrations of Bifidobacteria were significantly higher in the rats fed oligosaccharide- supplemented soy ice cream than that of the rats fed regular ice cream. In conclusion, oligosaccharide- supplemented soy ice cream suppressed lipid peroxidation and improved the got microbiota in diabetic rats compared with milk-based regular ice cream.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.4
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• pp.381-391
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• 1993

To evaluate the antioxidizing effect of flavonoid on fish oil and peroxidized fish oil, rats were fed with diets containing 5% corn oil (CO), 5% corn oil and 15% fresh fish oil (FO) or peroxidixed fish oil (PFO) for 4weeks. An half of FO and PFO group rats were injected with 10mg flavonoid (+)-catechin (a day per kg body weight) (FO-C and PFO-C). FO and FO-C group rats showed higher increase in body weight as compared to PFO, PFO-C group rats. Whereas, the opposite result was obtained in case of liver weight increase. In addition, catechin apparently reduced liver weight by 12~17%. Phospholipid, cholesterol, triglyceride and lipid peroxide content in serum and cholesterol, lipid peroxide content in liver and adipose tissue of PFO, PFO-C group rats were significantly higher than those of FO, FO-C one. These results suggested that catechin reduced the synthesis of lipid and protected effectively against lipid peroxidation. In fatty acids profile of neutral lipid and phospholipid, the ratio of polyunsaturated fatty acids (PUFA) versus saturated fatty acids (SFA) in PFO, PFO-C were lower than that of FO or FO-C because of ruduced PUFA. Contrary to our expectation, the enzyme activities of superoxide dismutase(SOD), catalase and glutathione peroxidase (GSH-Px) in rat liver of FO and FO-C group were lower than those of PFO and PFO-C group. These results were quite interesting and might be explained in terms of homeostasis. In case of total lipid in liver, $C_{20:5}$, $C_{22:6}$ fatty acids were decreased in rat fed peroxidized fish oil. In conclusion, catechin was considered to be an antioxidative and hepatoprotective drug and hypolipidemic agent.

• Korean Journal of Medicinal Crop Science
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• v.10 no.1
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• pp.51-57
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• 2002

The biological activities of immune modulating activities of the extracts from Echinacea purpurea, Chrysanthmum indicum L. and Circium japonicum var. ussuriense KITAMURA were compared. About 70% of the growth of human hepatocarcinoma and 80% of human gastric cancer cell was inhibited in adding 0.5mg/ml of the ethanol extracts of Echinacea purpurea, Chrysanthmum indicum L. and Circium japonicum var. ussuriense KITAMURA, respectively. The growth of human breast cancer cells was also inhibited in adding 0.5mg/ml of the extracts as well as 60% of the human cancer cells. It was proved that the growth of human normal lung cell, scored as 15% for the extracts. Overall selectivity of the extracts on several human cancer cell line was over 3, which is higher than those from the conventional herbs. The growth of both human immune B and T cells was enhanced up to 1.4 to 2.0 times by adding the extracts, compared to the controls. The secretion of tumor necrosis $factor-alpha(TNF-{\alpha})$ from T cell was also increased up to 94 pg/ml in adding the Echinacea purpurea ethanol extract (0.5mg/ml). Circium japonicum var. ethanol extract also increased up to about 96 pg/ml of interleukin-6(IL-6) from B cell.

• Journal of the Korean Magnetics Society
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• v.7 no.2
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• pp.82-89
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• 1997

Dependence of magnetoresistance on the thickness of Cu, type and thickness of buffer layer, and the stacking number of multilayer in the form buffer /$[Co(17{\AA}/Cu(t{\AA})]_{20}$ were investigated. To evaluate effect of annealing on this samples, X-ray diffraction analysis, vibrating sample magnetometer analysis, and magnetoresistance measurement (4-probe method) were performed. The magnetoresistance ratio exhibits a maximum of 21% for the multilayer with Cu thickness of 24$\AA$ and Fe buffer layer thickness of 50$\AA$. Deposition of film under low base pressure induces in increase magnetoresistance ratio by preventing oxidation. The multilayer annealed below 30$0^{\circ}C$ temperature allowed larger textured grain without loss in the periodicity. Magnetoresistance ratios of the multilayer with Cu thickness of 24$\AA$ and 36$\AA$ were increased due to the increase in the antiferromagnetically coupled fraction after annealing.