• International Journal of Vascular Biomedical Engineering
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• 제2권2호
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• pp.1-9
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• 2004

The history of studies in biology regarding reactive oxygen species (ROS) is approximately 40 years. During the initial 30 years, it appeared that these studies were mainly focused on the toxicity of ROS. However, recent studies have identified another action regarding oxidative signaling, other than toxicity of ROS. Basically, it is suggested that ROS are reactive, and degenerate to biomolecules such as DNA and proteins, leading to deterioration of cellular functions as an oxidative stress. On the other hand, recent studies have shown that ROS act as oxidative signaling in cells, resulting in various gene expressions. Recently ROS emerged as critical signaling molecules in cardiovascular research. Several studies over the past decade have shown that physiological effects of vasoactive factors are mediated by these reactive species and, conversely, that altered redox mechanisms are implicated in the occurrence of metabolic and cardiovascular diseases ROS is a collective term often used by scientist to include not only the oxygen radicals($O2^{-{\cdot}},\;{^{\cdot}}OH$), but also some non-radical derivatives of oxygen. These include hydrogen peroxide, hypochlorous acid (HOCl) and ozone (O3). The superoxide anion ($O2^{-{\cdot}}$) is formed by the univalent reduction of triplet-state molecular oxygen ($^3O_2$). Superoxide dismutase (SOD)s convert superoxide enzymically into hydrogen peroxide. In biological tissues superoxide can also be converted nonenzymically into the nonradical species hydrogen peroxide and singlet oxygen ($^1O_2$). In the presence of reduced transition metals (e.g., ferrous or cuprous ions), hydrogen peroxide can be converted into the highly reactive hydroxyl radical (${^{\cdot}}OH$). Alternatively, hydrogen peroxide may be converted into water by the enzymes catalase or glutathione peroxidase. In the glutathione peroxidase reaction glutathione is oxidized to glutathione disulfide, which can be converted back to glutathione by glutathione reductase in an NADPH-consuming process.

• The Korean Journal of Physiology and Pharmacology
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• 제7권3호
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• pp.163-168
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• 2003

The reactive oxygen species (ROS) are considered to be an important mediator in pancreatic ${\beta}$ cell destruction, thereby triggering the development of insulin-dependent diabetes mellitus. In the present study, HIV-1 Tat-mediated transduction of Cu,Zn-superoxide dismutase (SOD) was investigated to evaluate its protective potential against streptozotocin (STZ)-induced cytotoxicity in insulin-producing MIN6N cells. Tat-SOD fusion protein was successfully delivered into MIN6N cells in a dose-dependent manner and the transduced fusion protein was enzymatically active for 48 h. The STZ induced-cell destruction, superoxide anion radical production, and DNA fragmentation of MIN6N cells were significantly decreased in the cells pretreated with Tat-SOD for 1 h. Furthermore, the transduction of Tat-SOD increased Bcl-2 and heat shock protein 70 (hsp70) expressions in cells exposed to STZ, which might be partly responsible for the effect of Tat-SOD. These results suggest that an increased of free radical scavenging activity by transduction of Tat-SOD enhanced the tolerance of the cell against oxidative stress in STZ-treated MIN6N cells. Therefore, this Tat-SOD transduction technique may provide a new strategy to protect the pancreatic ${\beta}$ cell destruction in ROS-mediated diabetes.

• 한국식품과학회지
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• 제28권5호
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• pp.865-869
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• 1996

초파리를 이용하여 superoxide dismutase (SOD) 유사활성이 높다고 알려진 식물체 12 종의 효능을 평가하였다. 평가방법으로는 초파리 체내에서 superoxide를 발생시켜 초파리를 죽게 하는 paraquat (Pq)를 초파리 식이에 공급하고 상기 식물체 추출물을 투여하였을 때 초파리의 배양시간에 따른 생존율을 비교하여 분석하였다. Pq와 함께 마늘, 상치, 키위, 팽이버섯 추출물을 동시에 공급하였을 때 이들은 산소상해를 받고 있는 초파리에 비해 효과를 나타내지 못하였다. 그러나, 이들 식물체를 함유한 배지에 10일간 미리 적응시킨 후 식물체를 계속 공급하면서 60 mM 농도로 Pq를 함께 공급하였을 때 배양 1일 후 Pq 처리구의 생존율은 약 11%였으나 식물체 첨가구의 생존율은 $35{\sim}63%$로 높게 나타났다. 즉, 미리 적응시키면 SOD 유사활성이 있는 식물체는 초파리가 활성산소에 노출되더라도 산소독성에 예방효과를 나타낼 수 있음을 시사하고 있다. 한편, 초파리를 20 mM의 Pq가 첨가된 배지에 노출시켜 산소상해를 입히고 생존한 초파리만을 모아 60 mM의 Pq와 식물계 추출물이 함께 첨가된 배지로 옳기고 2일 후 생존율을 측정하였을 때 Pq첨가구 초파리의 생존율은 32%였으나 상치, 키위, 팽이버섯, 양파, 감, 고사리, 폴리플라워 첨가구 초파리의 생존율은 $64{\sim}82%$로 나타났다. 결과적으로 이들 식물체는 산소상해에 대하여 일종의 치유효과를 나타내는 것으로 판단되었다. 조사한 식물체 중 미나리, 표고버섯, 느타리 버섯, 브로콜리는 치유효과를 발휘하지 못하였다.

• 한국산학기술학회논문지
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• 제19권9호
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• pp.402-407
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• 2018

본 연구에서는 1.1-Diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical ($^{\cdot}OH$), 그리고 superoxide radical ($O_2{^-}$) 소거능 실험을 통해 쑥부쟁이의 항산화 효과를 평가하였다. 쑥부쟁이는 에탄올로 추출한 뒤, n-hexane, methylene chloride ($CH_2Cl_2$), ethylacetate (EtOAc), 그리고 n-butanol (n-BuOH)로 분획하였다. DPPH 라디칼 소거능 실험에서 모든 추출 및 분획물이 $10-100{\mu}g/mL$의 농도에서 농도 의존적으로 라디칼 소거능이 증가하였으며, 특히 EtOAc 분획물은 가장 강한 DPPH 라디칼 소거능을 나타내었다. 또한 쑥부쟁이는 $50{\mu}g/mL$ 농도에서 80% 이상의 $^{\cdot}OH$ 라디칼 소거율을 보였다. 특히 EtOAc 분획물은 $0.03{\mu}g/mL$에서 IC50 값을 나타내어 추출물과 분획물 중 가장 강한 $^{\cdot}OH$ 라디칼 소거능을 보여주었다. 또한, EtOAc 분획물은 $O_2{^-}$ 라디칼 소거능에서도 가장 강한 소거활성을 보였다. 이러한 결과는 쑥부쟁이가 산화스트레스로 인한 질병을 예방하는 천연 항산화제로서의 활용 가능성이 있음을 보여준다.

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.503-511
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• 2023

본 연구는 동백나무(Camellia japonica L.) 유박 추출물 및 분획물의 in vitro 항산화 활성에 대해 조사하였다. 동백나무 유박은 에탄올을 사용하여 추출하였으며, 이 후 부탄올(BuOH), 에틸아세테이트(EtOAc), 클로로포름 및 헥산을 이용하여 분획물을 조제하였다. 동백 유박 추출물 및 분획물의 항산화 활성을 평가하기 위해 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺), hydroxyl radical, superoxide anion (O₂^-) radical 소거능을 측정하였다. 동백 유박 추출물 및 분획물은 농도의존적으로 DPPH, ABTS⁺ 및 O₂^- radical 소거능을 증가시켜 항산화 활성을 나타내었다. 특히 동백 유박 BuOH 분획물은 다른 추출물 및 분획물에 비해 가장 높은 radical 소거능을 나타내었다. 동백 유박 BuOH 분획물의 총 폴리페놀 및 플라보노이드 함량은 각각 23.26 mg GAE/g 및 32.39 mg QE/g이었으며, 이는 다른 추출물 및 분획물보다 높은 수치임을 알 수 있었다. 동백 유박 BuOH 분획물 및 EtOAc 분획물의 cameliaside B 함량은 각각 102.37, 165.05 ㎍/g임을 확인하여 다른 추출물 및 분획물에 비해 높은 수치를 나타냄을 알 수 있었다. 따라서 동백 유박 추출 및 분획물 중에서 BuOH 분획물 및 EtOA c 분획물은 다른 추출 및 분획물에 비해 radical 소거능이 우수할 뿐 아니라 항산화 물질 함유량이 높아, 항산화 기능성 소재로 활용될 수 있을 것으로 사료된다.

• Biomolecules & Therapeutics
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• 제18권2호
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• pp.191-196
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• 2010

In the course of screening for antioxidant compounds by measuring the radical scavenging effect on 1,1-diphenyl- 2-picrylhydrazyl (DPPH), a total extract of the twigs of Stewartia koreana (Theaceae) was found to show potent antioxidant activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of six phenolic compounds, ampelopsin (1), catechin (2), proanthocyanidin-A2 (3), fraxin (4), (2R, 3R)-taxifolin-3-${\beta}$-D-glucopyranoside (5), and (2S, 3S)-taxifolin-3-${\beta}$-D-glucopyranoside (6), as active principles. Their structures were elucidated by spectroscopic studies. Compounds 1-6 were isolated for the first time from this plant. Among them, three compounds 1-3 showed the significant antioxidative effects on DPPH, and riboflavin originated superoxide quenching activity. In riboflavin-nitrobluetetrazolium (NBT)-light system, compound 1 showed better superoxide quenching activity than vitamin C.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1998년도 학술발표회
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• pp.26-26
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• 1998

Superoxide dismutases are metalloenzymes catalyzing the dimutation of superoxide anion radical to hydrogen peroxide and molecular oxygen. Examples of enzymes containing Cu, Mn and Fe as the redox-active metal have been characterized. Recently, an SOD containing one Ni atom per subunit was reported.(omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.145.1-145.1
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• 2003

Oxidative stress has been implicated in a range of disease states, including end-stage renal failure treated with hemodialysis [Westhuyzen J. et al, 2003]. Free radicals react with biological molecules and destroy the structure of cells, which eventually causes free-radical induced disease such as cancer, renal failure, aging, etc. Exogenous or endogenously produced nitric oxide (NO) inhibits superoxide-stimulated urea permeability. In the inner medulla, superoxide generation by local oxidases may stimulate urea transport, and the role of endogenous No may be to dampen this effect by decreasing superoxide levels ［Zimpelmann J. et al, 2003 (Epub ahead of print)］. (omitted)

• Toxicological Research
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• 제17권1호
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• pp.33-39
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• 2001

To evaluate the skin toxicity oj topical toluene application, toluene (35 mg/$cm^2$) was sequentially applied to the portion rat skin for five days. The topical toluene application resulted in increased xanthine oxidase activity and CYP content, and significantly decreased superoxide dismutase and glutathione peroxidase activities at five days in rat skin. Especially catalase activity was remarkably decreased in toluene-applied rat skin. And benzylalcohol dehydrogenase activity showed also a significant decrease in toluene-applied skin. On the other hand, histopathological ultrastructural examination revealed disrupted epidermal basement membrane, rared intercellular adhensions and degenerated keratin layer due to topical toluene application. Increased deposit of cerrous perhydroxide resulted from reaction with $H_2O_2$was abserved in toluene-treated animals. These results indicate that oxygen free radical may be responsible for ultrastructural changes in skin tissue by toluene application to rat skin.

• 대한가정학회지
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• 제42권5호
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• pp.193-203
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• 2004

This study examined the changes in the chemical components and antioxidant activity of Ecklonia cava according to the drying methods. As chemical components, the concentrations of minerals(K, Ca, Na, Mg, Fe, Cu, Mn and Zn), vitamins(vitamin C, ${\beta}$-carotene and ${\alpha}$-tocopherol) and the total polyphenols were analyzed. In additions, the antioxidant activity was determined by measuring the free radical(DPPH radical, superoxide anion radical, hydroxyl radical and hydrogen peroxide) scavenging activity and the linoleic acid peroxidation inhibitory activity. The mineral content was not affected by the drying methods. However, more vitamins were lost and the total polyphenol concentration was reduced as a result of sun-drying than by the other drying methods used. More of the total polyphenol was preserved by freezing-drying than by any of the other drying methods, which meant that there was a higher antioxidant activity after freeze drying.