• Journal of Korean Society on Water Environment
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• v.28 no.2
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• pp.219-223
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• 2012

The fixed solid catalysts such as glass bead, steel mesh, and $TiO_2$ coated ceramic bead were used to investigate effect of radical production at different frequencies. The radical production rate at 300 kHz was faster than that at 35 kHz without solid, but the tendency was changed with the presence of glass bead. The presence of glass beads create non-continuous points between the solid and liquid phases leading to increased formation of cavitation bubbles. However, the radical production decreased when steel mesh was used at 35 kHz although the surface area of contact with liquid was same when glass bead was used. Hence the solid catalyst did not always enhance the radical production. The radical production using $TiO_2$ coated ceramic bead was dramatically increased at 35 kHz due to the breakage of $TiO_2$ coated ceramic bead. Therefore the radical productions at 300 kHz using fixed solid catalysts generally increased while at 35 kHz the results fluctuated according to the experimental conditions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.117-123
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• 2002

This study was Performed to investigate the effect of kimchi intake on antiaging characteristics in the brain of senescence-accelerated mouse (SAM) in terms of free radical production and anti-oxidative enzymes. Two hundreds twenty SAM (20 mice) were divided into four groups and fed kimchi diet for 12 months. Experimental groups were kimchi free AIN-76 diet (control) group, Korean cabbage kimchi diet (KCK)group, 30% mustard leaf added Korean cabbage kimchi diet (MKCK) group, and mustard leaf kimchi diet (MLK) group. Concentrations of total free radical, OH radical and $H_2O_2$ of control group increased up to 123%, 262% and 174% of initial value (p<0.05) after one year. Increase in free radical production in kimchi groups due to aging was decreased by kimchi feeding. Among kimchi groups. MKCK and MLK groups showed greater inhibiting effect against free radical production than KCK. The concentration of TBARS in the bruin of control group also significantly increased up to 362% of initial value as aged (p<0.05) and production of TBARS in kimchi groups were decreased. When the activities of Cu, Zn-SOD, Mn-SOD, GSH-px and catalase of kimchi groups were compared to those of control at the same experimental period, anti-oxidative enzyme activities of kimchi groups were lower than those of control (p<0.05). But GSH/GSSG in kimchi groups were higher compared to control. In conclusion, decrease in free radical production and increase in anti-oxidative enzyme activities were observed from kimchi groups suggesting that kimchi might have important role on retarding aging. Among kimchi variety tested in this experiment, MKCK and MLK seem to have greater effect on inhibiting free radical production and increasing anti-oxidative enzyme activities than KCK.

• Environmental Engineering Research
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• v.10 no.3
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• pp.144-154
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• 2005

The use of ozone gained acceptance in the production of ultrapure water because of its powerful oxidizing ability. Ozone is currently used to deactivate microorganisms and remove organic contaminants. However, interest also exists in using radical species, which arc stronger oxidants than ozone, in such processes. One means of producing radical species is by corona discharge. This work investigates the use of a novel pulseless corona-discharge system for the removal of organic substances in ultrapure water production. The method combines corona discharge with electrohydrodynamic spraying of oxygen, forming microbubbles. Experimental results show that pulseless corona discharge effectively removes organics, such as phenol and methylene blue, in deionized water. The corona-discharge method is demonstrated to be comparable to the direct use of ozone at a high-applied voltage. The results also show that a minimum applied voltage exists for operation of the corona-discharge method. In this work, the minimum applied voltage is approximately 4.5 kV. The kinetic rate or phenol degradation in the reactor is modeled. Modeling results show that the dominant species of the pulseless corona-discharge reactor are hydroxyl radical and aqueous electron. Several radical species produced in the pulseless corona-discharge process are identified experimentally. The. major species are hydroxyl radical, atomic hydrogen species, and ozone.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2005.04a
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• pp.131-148
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• 2005

This study is peformed to investigate the effect of water extract from Vaccinium uliginosum L., on melanin production in B 16 melanoma cells, procollagen production and matrix metalloproteinase-1(MMP-1) inhibition in human fibroblast cells. One hundred grams of the Vaccinium uliginosum L. was extracted with 2000 mL of water($90^{\circ}C$, 16h, 2times). The water extracts were lyophilized and stored at $4^{\circ}C$ until used. Dry weight yields of extracts of Vaccinium uliginosum L. were $3\%$(w/w). Extracts from Vaccinium uliginosum L. showed scavenger activities on DPPH radical, superoxide anion radical, hydroxyl radical, hydrogen peroxide and singlet oxygen radical. And these substances inhibited release of cyiokines from human keratinocyte after UV B exposure. Therefore we confirmed that extracts from Vaccinium uliginosum L. had antioxidative effect. These substances inhibited purified tyrosinase activity and melanogenesis in B 16 melanoma cells treated/untreated IL-$1{\alpha}$. Moreover this extract stimulated procollagen production and inhibited MMP-1 production in human fibroblast cells treated/untreated IL-$1{\beta}$. Therefore we confirmed that extracts from Vaccinium uliginosum L. had whitening effect. And these substances decreased degree of wrinkle in hairless mouse skin that induced by UV B irradiation. Therefore we confirmed that extracts from Vaccinium uliginosum L. had anti-wrinkle effect. From the above results, it is possible that Vaccinium uliginosum L. may be developed to be an anti-melanogenesis agent and anti-wrinkle agent.

• Fisheries and Aquatic Sciences
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• v.25 no.6
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• pp.335-349
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• 2022

To optimize the hydrolysis conditions in the production of antioxidant hydrolysates from tuna cooking juice concentrate (TC) to maximize the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, TC containing 48.91% protein was hydrolyzed with Alcalase 2.4 L, and response surface methodology (RSM) was applied. The optimum hydrolysis conditions included a 2.2% (w/v) Alcalase concentration and 281 min hydrolysis time, resulting in the highest DPPH radical scavenging activity of 66.49% (0.98 µmol Trolox/mg protein). The analysis of variance for RSM showed that hydrolysis time was an important factor that significantly affected the process (p < 0.05). The effects of different drying methods (freeze drying, hot air drying, and vacuum drying) on the DPPH radical scavenging activity and amino acid (AA) profiles of TC hydrolysate (TCH) were evaluated. Vacuum-dried TCH (VD) exhibited an increase in DPPH radical scavenging activity of 81.28% (1.20 µmol Trolox/mg protein). The VD samples were further fractionated by ultrafiltration. The AA profiles and antioxidant activities in terms of the DPPH radical scavenging activity, 2,2'-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) radical scavenging activity, ferric reducing antioxidant power, and ferrous ion chelating activity were investigated. Glutamic acid, glycine, arginine, and cysteine were the major AAs found in the TCH fractions. The highest DPPH radical scavenging activity was found in the VD-1 fraction (< 5 kDa). The VD-3 fraction (> 10 kDa) exhibited the highest ABTS radical scavenging activity and ferric reducing antioxidant power. The ferrous ion chelating activity was the highest in VD-1 and VD-2 (5 to 10 kDa). In conclusion, this study provided the optimal conditions to obtain high antioxidant activities through TCH production, and these conditions could provide a basis for the future application of TCH as a functional food ingredient.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.05a
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• pp.145-148
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• 2000

• Advances in Traditional Medicine
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• v.10 no.4
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• pp.310-318
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• 2010

Verbena officinalis (Verbenaceae) has been used as herbal medicine or health supplement in both Western and Eastern countries for centuries. In the present study, we examined the anti-inflammatory and antioxidant activities of the methylene chloride fraction of V. officinalis (VMC). To elucidate the anti-inflammatory properties of VMC, we investigated the inhibition effects of nitric oxide production in interferon-gamma (IFN-$\gamma$) and lipopolysaccharide-stimulated mouse peritoneal macrophages. VMC suppressed nitric oxide production, inducible nitric oxide synthase and cyclooxygenase-2 expression dose-dependently without notable cytotoxicity. In various radical scavenging assays, VMC exhibited strong scavenging effect on DPPH radical, superoxide radical, nitric oxide radical and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) radical. VMC also showed potent reducing power. These findings strongly suggest that VMC may be beneficial in oxidative stress-mediated inflammatory disorders.

• Journal of Environmental Health Sciences
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• v.35 no.6
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• pp.532-537
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• 2009

The tropospheric ozone production mechanism for the gas phase additive oxidation reaction of hydroxyl radical (OH) with isoprene (2-methyl-1,3-butadiene) has been studied using cavity ring-down spectroscopy (CRDS) at total pressure of 50 Torr and 298 K. The applicability of CRDS was confirmed by monitoring the shorter (~4%) ringdown time in the presence of hydroxyl radical than the ring-down time without the photolysis of hydrogen peroxide. The reaction rate constant, $(9.8{\pm}0.1){\times}10^{-11}molecule^{-1}cm^3s^{-1}$, for the addition of OH to isoprene is in good agreement with previous studies. In the presence of $O_2$ and NO, hydroxyl radical cycling has been monitored and the simulation using the recommended elementary reaction rate constants as the basis to OH cycling curve gives reasonable fit to the data.

• Advances in Traditional Medicine
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• v.10 no.2
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• pp.51-58
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• 2010

Vitex rotundifolia (V. rotundifolia) has been used for treating headache, dizziness, toothache and removal of fever as a traditional medicine in Korea. In the present study, we examined the antioxidant and anti-inflammatory activities of 85% methanol extract of V. rotundifolia. In various radical scavenging assays, V. rotundifolia exhibited strong scavenging effect on 1, 1-diphenyl-2-picrylhydrazyl free radical, superoxide radical, nitric oxide. To elucidate the anti-inflammatory properties of V. rotundifolia, we investigated the inhibition effects of nitric oxide production in IFN-gamma and LPS-stimulated mouse peritoneal macrophages. V. rotundifolia suppressed nitric oxide production, iNOS and COX-2 expression dose-dependently through suppression of NF-$\hat{e}B$ activation without notable cytotoxicity. These findings mean that V. rotundifolia may be beneficial in oxidative stress-mediated inflammatory disorders.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.6
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• pp.1320-1331
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• 2009

Oxidative stress and inflammation are important events in the development of chronic inflammatory diseases including arthritis, atherosclerosis, diabetes, hypertension. Cynomorium songaricum (CS) has been used as a traditional Korean herbal medicine, and it is currently used in traditional clinics to treat frequent urination, spermatorrhea, weakness of the sinews and constipation in the folk medicine. The aim of this study was to determine whether fractionated extracts of CS inhibit free radical generation such as DPPH radical, superoxide radical, nitric oxide and peroxynitrite, production of nitrite an index of NO, $PGE_2$, iNOS, COX-2 and pro-inflammatory cytokines in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. Cytotoxic activity of extracts on RAW 264.7 cells was measured using 5-(3-caroboxymeth-oxyphenyl)-2H-tetra-zolium inner salt (MTS) assay. Our results indicated that the most superior extract which scavenged DPPH radical, reactive oxygen species (ROS) and RNS was CS ethyl acetate extract (CSEA). Moreover, CSEA significantly inhibited the LPS-induced NO, $PGE_2$ production and iNOS, COX-2 expression accompanied by an attenuation of TNF-$\alpha$, IL-$1{\beta}$ and IL-6 formation in macrophages. Furthermore, CSEA treatment also blocked LPS-induced intracellular ROS production and the activation of NF-${\kappa}B$. These findings indicate that CSEA inhibits the production of pro-inflammatory mediators and cytokines via the suppression of ROS production and NF-${\kappa}B$ activation. Take together, these results indicate that CSEA has the potential for use as an natural anti-oxidant and an agent of anti-chronic inflammatory diseases.