• Current Research on Agriculture and Life Sciences
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• 제30권2호
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• pp.110-114
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• 2012

In the present study, acetone extract and sub-fractions of Albizia amara stem bark were evaluated for their free radical potential. The results showed that the crude extract and all the fractions exhibited antioxidant and free radical scavenging activities under different in vitro assays. Among the different fractions, the ethyl acetate fraction exhibited higher DPPH and ABTS radical scavenging activities than the standard quercetin. A. amara stem bark might be valuable source of natural antioxidants that could be used for medicinal and food applications.

• Advances in Traditional Medicine
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• 제4권3호
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• pp.197-209
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• 2004

The study was aimed at evaluating the antioxidant and antimicrobial activities of methanol extract of Caesalpinia bonducella leaves (MECB) (Family: Caesalpiniaceae). The effect of MECB on antioxidant activity, reducing power, free radical scavenging (DPPH radical, nitric oxide radical, superoxide anion radical, hydroxyl radical and hydrogen peroxide radical scavenging), total phenolic content and antimicrobial activities were studied. The antioxidant activity of MECB increased in a dose dependent manner. About 50, 100, 250 and 500 g of MECB showed 53.4, 61.2, 69.1 and 76.2 % inhibition respectively on peroxidation of linoleic acid emulsion. Like antioxidant activity, the effect of MECB on reducing power increased in a dose dependent manner. The free radical scavenging activity of MECB was determined by DPPH radical scavenging method. The potency of this activity was increased with increased amount of extract. MECB was found to inhibit the nitric oxide radicals generated from sodium nitroprusside $(IC_{50}\;=\;102.8\;g/ml)$ whereas the $IC_{50}$ value of curcumin was 20.4 g/ml. Moreover, the MECB was found to scavenge the superoxide generated by photoreduction of Riboflavin. MECB was also found to inhibit the hydroxyl radical generated by Fenton reaction, where the $IC_{50}$ value is 104.17 g/ml compared with catechin 5 g/ml, which indicates the antioxidant activity of MECB. The MECB capable of scavenging hydrogen peroxide in a concentration-dependent manner. The amounts of total phenolic compounds were also determined. Antimicrobial activities of MECB were carried out using disc diffusion methods with five Gram positive, four Gram negative and four fungal species. The results obtained in the present study indicate that MECB leaves are potential source of natural antioxidant and antimicrobial agents.

• 약학회지
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• 제38권2호
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• pp.166-173
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• 1994

Sex hormones not only regulate external sexual characteristics but several internal biochemical processes. It is well accepted that life-span of female is longer than that of male. Life-span is closely related with aging process in which free radicals are known to be involved. We investigated the effect of testosterone on free radical generating systems and lipid peroxidation based on the sexual difference. Lipid peroxide levels of male and female mouse were increased proportionately with age, especially in male mouse. Increase in enzyme activity of aldehyde oxidase with age was observed in male mouse, while no siginificant change in enzyme activity was found in female mouse. Enzyme activity of xanthine oxidase also showed similar results. It, however, was not significant statistically. Lipid peroxide level and xanthine oxidase type conversion ratio of male and female mouse liver homogenate incubated at $37^{\circ}C$, increased remarkably in proportion to incubation time, especially in male mouse. Lipid peroxide level and aldehyde oxidase activity were measured in normal male mouse, castrated mouse and testosterone treated-castrated mouse. Castrated mouse group showed decrease in lipid peroxide level and aldehyde oxidase activity compared with normal group. Treatment of castrated mouse with testosterone, however turned the level of lipid peroxide and aldehyde oxidase activity back to normal. From the above results, it might be concluded that testosteron could increase the activities of free radical generating enzymes which would result in the formation of lipid peroxide, consequently leading to aging.

• 대한본초학회지
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• 제33권6호
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• pp.1-8
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• 2018

Objectives : Herbal medicinal mixture (JMB) are consisted of Caryophylli Flos, Aucklandiae Radix and Angelicae Dahuricae Radix. Each of herbal medicines has studied on anti-oxidant effect. So this study was conducted to investigate efficacy and potency of JMB on anti-oxidation. Methods : The JMB was extracted at room temperature by 80% ethanol. And total polyphenol contents, total flavonoid contents in JMB ethanol extract were determined by colorimetric method. Also, DPPH, ABTS free radical scavenging capacity and reducing power of JMB ethanol extract were measured at 100, 500, 1000, $5000{\mu}g/m{\ell}$ concentrations by spectrometric assay. Positive control was used BHA (butylated hydroxyanisole). Results : The total polyphenol contents and total flavonoid contents of the extract were 55.38 mg/TAEg, 513.72 mg/RUEg, respectively. Also, DPPH free radical scavenging capacity and reducing power of JMB ethanol extract in treated concentrations (100, 500, 1000, $5000{\mu}g/m{\ell}$) increased dose dependently. In particular, DPPH free radical scavenging capacity of JMB ethanol extract at 500, 1000, $5000{\mu}g/m{\ell}$ was similar to positive control (BHA) at high concentration (50, $100{\mu}g/m{\ell}$). ABTS free radical scavenging capacity of JMB ethanol extract at 500, 1000, 5000 ug/ml was similar to BHA at high concentration (50, $100{\mu}g/m{\ell}$). Also, reducing power was showed that JMB ethanol extract at $5000{\mu}g/m{\ell}$ was similar to BHA at high concentration (50, $100{\mu}g/m{\ell}$). Conclusions : These results suggest that JMB ethanol extract has effects to scavenge free radicals. Therefore, JMB has potential and applicable benefits for development of materials and products to have anti-oxidation functions.

• Natural Product Sciences
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• 제11권1호
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• pp.22-26
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• 2005

Hygrophila auriculata (K. Schum.) Heine is a wild herb commonly found in moist places on the banks of tanks, ditches and paddy fields throughout India and is one of the main sources of Ayurvedic 'Rasayana' drug. The free radical scavenging potential of 50% aqueous alcoholic extract of H. auriculata (HAEt) was studied for DPPH scavenging activity, nitric oxide, hydroxyl radical and ferryl bipyridyl complex scavenging activity along with lipid peroxidation and total antioxidant capacity inhibition using Thiobarbituric acid reactive substances (TBARS) in rat liver homogenate. Integral antioxidative capacity was determined by photochemiluminescence assay. HAEt showed good radical scavenging activity at various concentrations $(200-1000\;{\mu}g/ml)$ against 1,1 diphenyl, 2-picrylhydrazyl (DPPH) (32.32-77.02%) with moderate scavenging activity against Nitric oxide (12.46-52.84%), hydroxyl radical (11.69-55.26%), ferryl bipyridyl complex (17.66-58.67%) and lipid peroxidation (0.829-0.416nmoles/mg protein). The above results indicate HAEt to be very effective antioxidant. It was suggested that the varied therapeutic activities claimed for the plant in the Indian indigenous systems of medicine may be in the part due to the free radical scavenging and/ or potent antioxidant activity.

• 디지털융복합연구
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• 제14권8호
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• pp.261-267
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• 2016

본 논문에서는 센서 네트워크를 위한 Radical line을 기반으로 한 센서 노드간의 Range-free 지역화 알고리즘에 대해 연구한다. 무선 센서 네트워크에서 라우팅 기법은 센서 네트워크의 전체적인 에너지 소모량을 감소시키거나 모든 센서 노드들의 균등한 에너지 소비를 유도해야 한다. 특히 데이터가 전송할 데이터의 양이 많아지면 에너지 소모가 심해지는데 이를 극복하기 위한 새로운 방식들이 제안되었다. 그 결과 전체적인 에너지 소모량을 균등하게 조절할 수 있게 되었다. 이를 위해 논문에서도 적은 연산으로 주변 노드의 위치정보를 획득할 수 있는 지역화 알고리즘을 설계한다. 알고리즘의 연산을 위해 Radical Line을 적용한다. 실험환경은 운영체제는 윈도우 7, 플랫폼은 Visual C++ 2010으로 실험하였다. 실험결과 0.1837의 에러율로 지역화를 수행할 수 있었다.

• 농업과학연구
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• 제45권4호
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• pp.761-767
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• 2018

Degenerative diseases are commonly associated with excess free radicals. Acer okamotoanum, a plant endemic to Korea, is reported to have anti-oxidant, anti-cancer, and anti-viral activities. We previously isolated flavonoids from the ethyl acetate fraction of A. okamotoanum such as quercitrin (QU), isoquercitrin (IQ), and afzelin (AF). In the present study, the in vitro antioxidant activity of flavonoids such as QU, IQ, and AF isolated from the ethyl acetate fraction of A. okamotoanum were investigated by measuring the free radical scavenging activity including 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical ($^{\cdot}OH$), and superoxide anion ($O_2{^-}$). The flavonoids (QU, IQ, and AF) concentration-dependently showed a DPPH radical scavenging activity. In particular, QU and IQ showed a higher DPPH radical scavenging activity than that of AF. In addition, the flavonoids (QU, IQ, and AF) at $10{\mu}g/mL$ showed over an 80% scavenging effect against $^{\cdot}OH$ radical production. Furthermore, the $O_2{^-}$ radical scavenging activity of the flavonoids, QU, IQ, and AF increased in a dose-dependent manner. Particularly, IQ exerted the strongest scavenging activities against $^{\cdot}OH$ and $O_2{^-}$ radicals among the other flavonoids. These results indicate that the flavonoids from A. okamotoanum, in particular IQ, would have a protective activity against oxidative stress induced by free radicals, and potentially be considered as a natural antioxidant agent.

• 동아시아식생활학회지
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• 제3권2호
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• pp.121-128
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• 1993

This study was intended to clarify the protective mechanism of diallyl disulfide on the carbon tetrachloride-induced hepatotoxicity in mice. It was observed that a powerfully increment of serum alanine aminotransferase activity and hepatic lipid peroxide content after carbon tetrachloride injection were markedly inhibited by the pretreatment of diallyl disulfide (20mg/kg) for 5 days. It was also observed that hepatic aminopyrine demethylase and xanthine ocidase as free radical generating enzymes as well as superoxide dismutase and catalase activities as free frdical scavenging enzymes and hepatic glutathione content were not changed by the pretreatment with diallyl disulfide. But, treatment with diallyl disulfide did signifiantly increase cytosolic glutathione S-transferase activity. However, glutathione S-transferase activity in the presence of diallyl disulfide was not affected in vitro. Therefore, it is concluded that mechanism for the observed preventive effect ofdiallyl disulfide against the carbon tetrachloride-induced hepatotoxicity can be due to the engancement of glutathione S-transferase activity.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.381.2-381.2
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• 2002

There is now increasing evidence that free radicals and active oxygen species are involved in a variety of pathological events. often associated with ageing. Free radical-mediated cell damage and free radical attack on polyunsaturated fatty acids result in the formation of lipid radicals. These lipid radicals react readily with molecular oxygen to produce peroxy radicals responsible for initiating lipid peroxidation. The peroxidation of cellular membrane lipid can lead to cell necrosis and considered to be implicated in a number of pathophysiological conditions as well as in the toxicity of many xenobiotics. (omitted)

• 한국수산과학회지
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• 제31권6호
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• pp.927-932
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• 1998

일본, 따렌 등에 분포되어 있고 우리나라에서 동해안, 서해안, 남해에서 흔히 볼 수 있는 해조류로서, 조간대의 바위위에서 서식하는 빨강 검둥이과 홍조류인 보라우무 (Symphyocladia latiuscula)를 대상으로 하여 안정한 free radical인 1,1-diphenyl-2-picrylhydrazyl (DPPH)를 사용하여 그 소거능을 측정하고, 또한 생체내의 과산화지질을 평가하는 방법으로 과산화지질 분해산물인 malondialdehyde를 thiobarbituric acid(TBA)로 비색정량하는 방법과 Hepatocyte에 의해 생성되는 free radical 생성량 측정 등의 다양한 방법을 통하여 항산화능을 측정하였다. DPPH radical을 이용한 항산화활성 검색에서 강력한 radical 소거 효과를 나타내었다. 각 용매 분획별로 항산화활성을 살펴본 결과 수층을 제외한 모든 분획들에서 농도 의존적으로 항산화활성이 나타났다. 특히 dichloromethane과 hexane 가용성 분획의 항산화활성이 가장 크게 나타났다. 지질과산화 억제 효과에서도 유사한 결과를 보였으며 dichloromethane 가용성 분획의 항산화활성이 가장 높게 나타났으며 L-ascorbic acid의 항산화활성과 비교하여 더 높은 활성을 나타내었다. Free radical 생성 억제 효과에서도 dichloromethane 가용성 분획의 경우 control과 비교하여 0.1 mg/ml에서 $50\%$ 이상의 저해효과를 나타내었다.