• Journal of Radiation Industry
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• v.5 no.3
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• pp.221-225
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• 2011

To detect superoxide anion ($O_2{\cdot}^-$) or singlet oxygen ($^1O_2$) in biological systems during gamma irradiation, specific chemical probes, 4,5-dihydroxy-1,3-benzene disulfonic acid (Tiron) or 2,2,6,6-tetramethyl-piperidine (TEMP), were evaluated. Tiron or TEMP spin adducts was structurally stable in aqueous solution during gamma irradiation up to 500 or 1,000 Gy, respectively. The signal of Tiron semiquinone radical, a spin adduct of Tiron upon reaction with $O_2{\cdot}^-$, was slightly increased by gamma irradiation. This trend was dose-dependently manifested in $O_2$-saturated aqueous solution using nitro blue tetrazolium (NBT), a common probe for both hydrated electron ($e{^-}_{aq}$) and $O_2{\cdot}^-$. In contrast, a spin adduct of TEMP, was never inducible by gamma irradiation, while its signal was substantially enhanced by photosensitization of riboflavin. These results suggest that Tiron and NBT or TEMP could be utilized to detect $O_2{\cdot}^-$ or $^1O_2$ in biological systems during gamma irradiation, although $O_2{\cdot}^-$ or $^1O_2$ are not the main reactive oxygen species produced by water radiolysis.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.2
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• pp.153-159
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• 2011

In this study, we investigated rice bran fermented by Bacillus subtilis (RFB) at $40^{\circ}C$ for 36 h to develop a new natural antioxidant and whitening agent for new natural cosmetics. RFB showed reactive oxygen species (ROS) scavenging activities in 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, superoxide radical scavenging activities and hydroxyl radical scavenging activities at a concentration of $100 \;{\mu}L$/mL. DPPH, superoxide radical scavenging activities and hydroxyl radical scavenging activities were higher in the RFB than in the RB. Inhibitory activity on auto-oxidation of linoleic acid is also highest at a concentration of $100 \;{\mu}L$/mL. RFB showed the higher inhibitory activity than RB in auto-oxidation. RFB reduced intracellular tyrosinase activity about 80 % at a concentration of $100 \;{\mu}L$/mL. Therefore, we suggest that RFB could be used as a useful antioxidant and whitening agent.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.758-763
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• 1999

The protective effects of sea tangle (Laminaria japonica) extract and fucoidan components on the attack of oxygen radicals in kidney were studied, Sprague-Dawley (SD) male rats (210 $\pm$ 5 g) were with fed experimental diets of Dasi-Ex group (sea tangle extract powder of $4.0\%$ added to control diet), Euco-I, II and III groups (fucoidan powder of 1, 2 and $3\%$, respectively, added to Dasi-Ex group) for 45 days, Hydroxyl radical formations were significantly decreased ($10\~15\%$ and $15\~30\%$) in mitochondria and microsomes of Dasi-Ex and Fuco-I, II, III groups compared with control group. Hydrogen peroxide formations were also significantly decreased ($10\~15\%$) in microsomes of Dasi-Ex and Fuco-I, II, III groups compared with control group. Significant differences in mitochondrial basal oxygen radical (BOR) and microsomal induced oxygen radical (IOR) formations of Dasi-Ex and Fuco-I groups could not be obtained, but mitochondrial BOR and microsomal IOR formations were significantly decreased ($12\~15\%$ and $13\~14\%$) in Fuco-II and III groups compared with control group. BOR formations were significantly decreased ($12\~25\%$) in microsomes of Dasi-Ex and Fuco-I, II, III groups, and IOR formations were also significantly decreased ($10\~15\%$) in mitochondria of Fuco-I, II, III groups compared with control group, Significant differences in mitochondrial Mn-SOD activities of Dasi-Ex group could not be obtained, but mitochondrial Mn-SOD activities were dose-dependently increased by $8\%,\;16\%$ and $36\%$ in Fuco-I, II and III groups compared with control group, Mn-SOD activities an microsome were significantly increased about $20\%$ in Dasi-Ex group, while they were remarkably increased about $40\%$ in Fuco-I, II and III groups compared with control group. lipid peroxide contents were significantly decreased about $15\%$ and $15\~25\%$ in mitochondria and microsomes of Fuco-II and III groups. Membrane fluidities resulted in marked increases ($20\~35\%$ and $17\~24\%$) in mitochondria and microsomes of Dasi-Ex and Fuco-I, II and III groups. These results suggest that administrations of fucoidan added to sea tangle may play a pivotal role in attenuating attack of oxygen radicals in kidney.

• Journal of Preventive Medicine and Public Health
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• v.27 no.1 s.45
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• pp.84-106
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• 1994

Hyperbaric oxygen (HBO) therapy for carbon monoxide (CO) poisoning eventually inducing the hypoxia-reoxygenation condition, may produce oxygen free radicals, which forms 8-hydroxydeoxyguanosine (8-OH-dG) by attacking C-8 position of deoxyguanosine (dG) in DNA. Effects of oxygen partial pressure or duration of HBO therapy with or without CO poisoning on the tissue 8-OH-dG formation were investigated. Male Sprague-Dawley rats were grouped and exposed to air (control group), 4000 ppm of CO for 10 to 30 minutes (CO only group), air for 30 minutes after 30 minute exposure to 4000 ppm of CO(CO-air exposure group), HBO after 30 minute exposure to 4000 ppm of CO(CO-HBO group), or HBO therapy fo. $10{\sim}120$ minutes(HBO only group). The 8-OH-4G concentrations in the brain and the lung tissues were measured with high performance liquid chromatography and electrochemical detector (ECD). Average concentrations of the 8-OH-dG of each group were statistically compared. In the brain tissues, 8-OH-dG concentrations of the CO only group, the CO-air exposure group, and the CO-HBO group did not significantly differ from those of the control group. Similar insignificance was also found between the CO-HBO group and the HBO only groups. No appreciable dose-response relationship was observed between the 8-OH-dG concentration and the oxygen partial pressure or the duration of HBO. However, the 8-OH-dG concentrations of the 30 minute CO only group were higher than those of the CO-air exposure group (p-value<0.05). In the lung tissues, there were no significant differences between the 8-OH-dG concentrations of the control group and those of the CO only group, the CO-air exposure group, and the CO-HBO group. However, mean 8-OH-dG concentration of the CO-air exposure group was significantly higher than that of the CO only group under the same CO exposure condition(p-value<0.05). With the duration of CO exposure, the 8-OH-dG concentrations of the lung tissues decreased significantly (p-value<0.05). The concentrations of 8-OH-dG in the lung tissues proportionally increased with the duration of HBO, but no such relation was observed with the oxygen partial pressure. These results suggest that the brain may be more resistant to oxygen free radicals as compared with the lungs, and that oxygen toxicity following HBO may be affected by factors other than oxygen free radicals.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.126-126
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• 2000

다이아몬드상 카본(DLC) 필름은 경도가 높고, 마찰계수가 낮다는 장점을 가지고 있기 때문에 내마모성 코팅이나 윤활성코팅에 응용을 위한 연구가 활발히 진행중이다. 하지만 마찰계수가 주변환경에 매우 큰 영향을 받는다는 단점이 있다. 이러한 단점은 DLC필름의 응용에 대한 저해 요인이 되며, 이 점을 보완하기 위해서 DLC 필름에 Si을 첨가하는 연구들이 진행되고 있다. 본 실험에서는 r.f-PACVD 법을 이용하여 Si이 첨가된 DLC 필름의 주위 환경 변화에 따른 마찰특성의 변화를 연구하였다. 사용한 반응 가스는 벤젠(C6H)과 희석된 Silane(SiH4 : H2 = 10 : 90)이며, 희석된 Silane과 벤젠의 첨가비율을 조절하여 필름내 Si의 함량을 조절하였고, 증착시 바이아스의 전압은 -400V로 하였다. 마찰테스트는 Ball-on-Disk type의 조건에서 대기, 건조공기, 진공의 세가지 분위기에서 마찰테스트를 실행하였다. 실험결과 마찰계수는 건조공기, 대기, 진공의 순으로 증가하였고, 필름내에 포함되어 있는 Si의 양이 증가할수록 마찰계수는 낮고 안정한 값을 나타내었다. Tribochemiacal 분석과, ball과 track의 전자현미경 사진 분석 결과, 진공에 비해서 건조공기와 대기중에서 마찰계수가 낮은 것은 DLC 필름내에 마모 track 중심부에 Si-C-O 계의 화합물이 형성되어, 이 화합물이 마찰계면에 존재하여 마찰계수를 낮추었음을 확인하였다. 그리고 대기중에서 실험한 경우, 습기의 존재로 인해 마모입자가 볼의 표면에서 엉김으로써 건조공기의 상태에서 보다 높은 마찰저항을 갖게 됨으로 인하여 마찰계수가 높아짐을 알 수 있었다.a)는 as-deposit 상태이며, 그림 1(b)는 45$0^{\circ}C$, 60min 열처리한 plan-view TEM 사진이다.dical의 영향을 조사하였으며 oxygen radical의 rf power에 따른 변화는 OES(Optical emission spectroscopy)를 사용하였다. 너무 적은 oxygen ion beam flux나 oxygen radical은 film의 전도도 및 투과도를 저하시켰고 반면 너무 과도한 flux의 증가 시는 전도도는 감소하였고 투과도는 증가하는 경향을 보였다. 기판에 도달하는 oxygen ion flux는 faraday cup을 이용하여 측정하였으며 증착된 ITO film은 XPS, UV-spectrometer, 4-point probe를 이용하여 분석하였다. 때문으로 생각되어진다. 또한, 성장 온도가 낮아짐에 따라 AlGaN의 성장을 저해하기 때문으로 판단된다. 성장 온도 변화에 따라 성장된 V의 구조적 특성 및 표면 거칠기 변화를 관찰하여 AlGaN의 성장 거동을 논의하겠다.034, 0.005 정도로 다시 감소하였다. 박막의 유전율은 약 35 정도의 값을 나타내었으며 X-선 회절 data로부터 분석한 박막의 변형은 증온도에 따라 7.2%에서 0.04%로 감소하였고 이 이경향은 유전손실은 감소경향과 일치하였다.는 현저하게 향상되었다. 그 원인은 SB power의 인가에 의해 활성화된 precursor 분자들이 큰 에너지를 가지고 기판에 유입되어 치밀한 박막이 형성되었기 때문으로 사료된다.을수 있었다.보았다.다.다양한 기능을 가진 신소재 제조에 있다. 또한 경제적인 측면에서도 고부가 가치의 제품

• Journal of Life Science
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• v.7 no.1
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• pp.10-16
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• 1997

This study was designed as a part of efforts to investigate the biochemical pollutant markers for diagnosis of marine pollutions by changes in oxygen radicals and their scavenger enzymes of the flounder (Paralichthys olivaceus)in Yellow Sea of Kores. Protein contents in brian and muscle of cultured flounder in Yellow Sea were remarkably lower(30-45% and 25-45%, respectively) than those of wild flounders in Pohang(control) of East Sea. Lipid peroxide(LPO) levels in serum of cultured and wild flounders in Yellow Sea were significanltly higher (30-80% and 125-145%, respectively)than those of wild flounder in Pohang. Hydroxide radical formations and superoxide dismutase(SOD) activities in serum of cultured flounders in Yellow Sea were significantly 15-30% and 15-35% lower than those of wild flounders in Pohang, but glutathione peroxidase (GSHPx) activities in brain of cultured flounders in Yellow Sea were significantly 15-25% higher than those of wild flounders in Pohang. It is believed that significantly decreases of protein contents in brain anad muscle, remakable increases of malondialdehyde(LPO) in serum and glutathione peroxidase (GSHPx)in brain of cultured flounders of Yellow Sea may be used as a biochemical pollutant markers for diagnosis of marine pollutions.

• Journal of Oriental Physiology
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• v.14 no.2 s.20
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• pp.199-208
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• 1999

As the average life span have been lengthened and the rate of senile population have been raised, chronic degenerative diseases incident to aging has been increased rapidly and become a social problem. With this social background, recently, the facts that oxygen radicals(OR) have toxic effects on Central Nervous System and Peripheral Nervous System and cause neuropathy such as Parkinson's Disease, Alzheimer Disease have been turned out, and accordingly lots of studies on the mechanism of the toxic effects of OR on nerves, the diseases caused by OR and the approaches to curing the diseases have been made. The purpose of this study is to examine the toxic effects caused by Glucose Oxidase(GO) and the effects of herbal extracts such as Chilbokyeum(CBY) on the treatment of the toxic effects. For this purpose, experiments with the cultured cell from the cerebrums of new born mice were done. The results of these experiments were as follows. 1. GO, a oxygen radical, decreased the survival rate of the cultured cells on NR assay and MTT assay 2. GO, a oxygen radical, increased lipid peroxidation and the amount of LDH. 3. CBY have efficacy of decreasing lipid peroxidation. 4. CBY have efficacy of decreasing the amount of LOH. From the above results, It is concluded that Chilbokyeum has marked efficacy as a treatment for the damages caused in the GO-mediated oxidative process. And Chilbokyeum is thought to have certain pharmacological effects on controlling over aging and treating Dementia. Further clinical study of this pharmacological effects of Chilbokyeum should be complemented.

• Korean Journal of Agricultural Science
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• v.45 no.3
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• pp.509-519
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• 2018

This study was investigated the anti-oxidant property and neuro-protective effect of Cirsium japonicum var. maackii (CJM) against oxidative stress in hydrogen peroxide ($H_2O_2$)-induced C6 glial cells. We measured the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical (${\cdot}OH$), and superoxide ($O_2{^-}$) radical scavenging activities of an ethanol extract and four fractions [n-Butanol, ethyl acetate (EtOAc), $CHCl_3$, and n-Hexane] from CJM. The results of this study show that the extract and all fractions from CJM had a dose-dependent DPPH radical scavenging activity. In particular, the EtOAc fraction exhibited the strongest scavenging effect with 88.23% at a concentration of $500{\mu}g/mL$. In addition, the EtOAc fraction from CJM also effectively scavenged ${\cdot}OH$ radicals and $O_2{^-}$ radicals, compared to other extract and fractions. In C6 glial cells, $H_2O_2$ markedly decreased the cell viability as well as increased lactate dehydrogenase (LDH) release and reactive oxygen species (ROS) production. However, the EtOAc fraction of CJM attenuated the cellular damage from the oxidative stress by elevating the cell viability and inhibiting the LDH release and ROS over-production compared with the $H_2O_2$-treated control group. Our findings indicate that the EtOAc fraction from CJM has antioxidant effect and neuro-protective effect against oxidative stress, suggesting that it can be used as a natural antioxidant and therapeutic agent for the prevention of neurodegenerative disorders.

• Preventive Nutrition and Food Science
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• v.22 no.1
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• pp.16-20
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• 2017

This study investigated the antioxidant activity of functional beverage concentrates containing herbal medicine extracts (FBCH) using various antioxidant assays, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity, and reducing power assay. The total polyphenolic content of FBCH (81.45 mg/100 g) was higher than Ssanghwa tea (SHT, 37.56 mg/100 g). The antioxidant activities of FBCH showed 52.92% DPPH and 55.18% ABTS radical scavenging activities at 100 mg/mL, respectively. FBCH showed significantly higher antioxidant activities compared to the SHT (DPPH, 23.43%; ABTS, 22.21%; reducing power optical density; 0.23, P<0.05). In addition, intracellular reactive oxygen species generation significantly decreased in a concentration-dependent manner following FBCH treatment. These results suggest that the addition of herbal medicine extract contributes to the improved functionality of beverage concentrates.

• Journal of Plant Biotechnology
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• v.36 no.3
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• pp.219-223
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• 2009

Oxidative stress derived from excess reactive oxygen species (ROS) is a major damaging factor for plants exposed to environmental stresses. Sweetpotato [Ipomoea batatas (L.) Lam] has a relatively broad adaptability to harsh environmental conditions compared to other staple crops. In this study, to select stress-tolerant sweetpotato cultivars for sources of molecular breeding on marginal lands, we evaluated the ion leakage values in 10 different cultivars after treatment of methyl viologen (MV), an ROS-generating nonselective herbicide, to leaf discs. DPPH radical scavenging activity and the contents of total phenolics were also investigated. The ion leakage of each cultivar showed a diverse value, which is well correlated with DPPH radical scavenging activity of each cultivar. DPPH radical scavenging activity also showed a high corelation with the contents of total phenolic contents. Three cultivars of Yanshu 8, Shinhwangmi and Shinzami showed high antioxidant activity. Our results suggest that a simple and efficient DPPH radical scavenging activity would be a suitable method to select potential cultivars with enhanced tolerance to multiple environmental stress.