• Title/Summary/Keyword: free radical scavenger

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Bioactive Phenolic Constituents from the Culms of Phyllostachys bambusoides

  • Kim, Hyun-Jung;Kang, Min-Ah;Kim, So-Hyun;Yim, Soon-Ho;Lee, Ik-Soo
    • Natural Product Sciences
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    • v.17 no.4
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    • pp.267-272
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    • 2011
  • In our search for bioactive phenolics from plants, the culms of Phyllostachys bambusoides has been selected for investigation of anti-cariogenic and 1,1-diphenylpicrylhydrazyl (DPPH) radical scavenging agents based on the initial screening results. Fractionation process of n-hexane and $CHCl_3$ extracts afforded four phenolic constituents, ferulic acid (1), vanillin (2), coniferaldehyde (3), and coniferyl alcohol (4) as guided by their DPPH free radical scavenging activities. Additionally, activity-guided fractionation of EtOAc extract with anti-cariogenic activity has resulted in the isolation of coniferaldehyde (3), 2,6-dimethoxy-p-benzoquinone (5), p-methoxycinnamic acid (6), (${\pm}$)-balanophonin (7), and 6-methoxychromanone (8). The structures of 1 - 8 were determined by spectroscopic data interpretation, and also by comparison of their data with the published values. Phenolic compounds 1 - 4 exhibited similar DPPH radical scavenging activities compared with the synthetic antioxidant, butylated hydroxytoluene (BHT), and compounds 3 and 5 - 8 showed significant antibacterial activity against cariogenic oral streptococci, Streptococcus mutans and S. sobrinus.

The Preventive Inhibition of Chondroitin Sulfate Against the $CCl_4$-Induced Oxidative Stress of Subcellular Level

  • Lee, Jin-Young;Lee, Sang-Hun;Kim, Hee-Jin;Ha, Jong-Myung;Lee, Sang-Hyun;Lee, Jae-Hwa;Ha, Bae-Jin
    • Archives of Pharmacal Research
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    • v.27 no.3
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    • pp.340-345
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    • 2004
  • Our work in this study was made in the microsomal fraction to evaluate the lipid peroxidation by measuring superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA) and to elucidate the preventive role of CS in the $CCl_4$-induced oxidative stress. The excessive lipid peroxidation by free radicals derived from $CCl_4$ leads to the condition of oxidative stress which results in the accumulation of MDA. MDA is one of the end-products in the lipid peroxidation process and oxidative stress. MDA, lipid peroxide, produced in this oxidative stress causes various diseases related to aging and hepatotoxicity, etc. Normal cells have a number of enzymatic and nonenzymatic endogenous defense systems to protect themselves from reactive species. The enzymes in the defense systems, for example, are SOD, CAT, and GPx. They quickly eliminate reactive oxygen species (ROS) such as superoxide anion free radicalㆍO$^{[-10]}$ $_2$, hydrogen peroxide $H_2O$$_2$ and hydroxyl free radicalㆍOH. CS inhibited the accumulation of MDA and the deactivation of SOD, CAT and GPx in the dose-dependent and preventive manner. Our study suggests that CS might be a potential scavenger of free radicals in the oxidative stress originated from the lipid peroxidation of the liver cells of $CCl_4$-treated rats.

Antioxidant Effects of the Extracts of Acanthopanax senticosus (가시오갈피 추출물의 항산화효과)

  • Jin, Li-Hua;Han, Sang-Sup;Choi, Yong-Soon
    • Korean Journal of Pharmacognosy
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    • v.33 no.4 s.131
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    • pp.359-363
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    • 2002
  • Antioxidant properties of the extracts of Acanthopanax senticosus were investigated. The dried roots, stems or leaves were extracted with hot water or ethanol each. The ethanol extracts exhibited higher potency than aqueous extracts in scavenging free radicals and in inhibiting microsomal lipid peroxidation: the aqueous extracts of stems showed higher anti-oxidant effects than the root extracts. Copper-mediated LDL oxidation was also protected by the ethanol exlracts: antioxidant effects of the extracts tested were stronger than ascorbic acid, but not butylated hydroxytoluene. The activity of angiotensin converting enzyme was effectively suppressed by the aqueous extracts of the stems. However, in vivo antioxidant properties of the ethanol extracts of the stems did not seem to be significant, judged from the lipid peroxide values of serum and liver in normal mice. Thus, the ethanol extracts of the stems were shown to be more potent for protecting biological systems against various oxidant stresses in vitro, but not in vivo.

Potential Biological Activities of Magnoflorine: A Compound from Aristolochia debilis Sieb. et Zucc

  • Li, Chunmei;Wang, Myeong-Hyeon
    • Korean Journal of Plant Resources
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    • v.27 no.3
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    • pp.223-228
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    • 2014
  • Magnoflorine, an important compound in Aristolochia, was usually used as an anxiolytic chemical. In this study, the magnoflorine was isolated from Aristolochia and the biological activities such as antioxidant, ${\alpha}$-tyrosinase inhibitory, anti-inflammatory, and anticancer activities were investigated. The magnoflorine showed significant antioxidant activity as a 2,2-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenger, $50{\mu}g/mL$ of the magnoflorine scavenged about 70.8% of all the free radicals. And it was good at ${\alpha}$-tyrosinase inhibiting, $100{\mu}g/mL$ of the magnoflorine inhibited 36.5% of the tyrosinase. High dosage of magnoflorine inhibited the inflammation production nitric oxide (NO), and the magnoflorine protected the murine macrophage cells (RAW 264.7) from LPS-induced apoptosis. The cell viability of human colon cancer calls (HT-29) was around 100% when treated with different dose of magnoflorine, it's suggesting that magnoflorine had no anticancer effect.

Cell Cycle Regulation and Antioxidant Activity of Psammaplin A, A Natural Phenolic Compound from Marine Sponge

  • Jiang, Ya-Hong;Ryu, Seung-Hee;Ahn, Eun-Young;You, Song;Lee, Burm-Jong;Jung, Jee-H;Kim, Dong-Kyoo
    • Natural Product Sciences
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    • v.10 no.6
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    • pp.277-283
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    • 2004
  • Psammaplin A (PSA), a naturally occurring biophenolic compound has been demonstrated to deliver significant cytotoxicity to many cancer cell lines. In this article, we investigated the effect of PSA on cell cycle progression of lung cancer cells (A549). It was found that PSA could slightly perturb the cell cycle progression of A549 cells and lead to the cell cycle arrest at G2/M phase, indicating PSA might disturb the mitosis process of A549 cells. In addition, inspired by the two phenolic groups in the structure of PSA, the antioxidant activity of it has been evaluated. Although PSA was weak in scavenging the stable free radical 1,1-diphenyl-2-picrylhyrazyl (DPPH), it showed stronger ABTS radical scavenging activity than ascorbic acid in TEAC assay. Furthermore, it was found that PSA could effectively prevent DNA strand scission induced by oxidative stress. These results suggest that PSA have both cell cycle regulation and antioxidant activities. Herein, we suggest that PSA would be a very interesting and promising candidate to be developed as a multi-function drug.

Antioxidant Activity of (8E,13Z,20Z)-Strobilinin/(7E,13Z,20Z)-Felixinin from a Marine Sponge Psammocinia sp.

  • Jiang, Ya-Hong;Ryu, Seung-Hee;Ahn, Eun-Young;You, Song;Lee, Burm-Jong;Jung, Jee-H;Kim, Dong-Kyoo
    • Natural Product Sciences
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    • v.10 no.6
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    • pp.272-276
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    • 2004
  • During the course of our screening for bioactive metabolites from marine sponges, EZZ, the inseparable 1:1 mixture of (8E,13Z,20Z)-strobilinin and (7E,13Z,20Z)-felixinin has been found to deliver significant cytotoxicity against some cancer cell lines. In this study, the antioxidant activity of EZZ was first time evaluated by a series of antioxidant assays. It was found that EZZ was weak in scavenging the stable free radical 1,1-diphenyl-2-picrylhyrazyl (DPPH), but it was comparable to ascorbic acid in scavenging ABTS and superoxide radicals. In addition, EZZ could protect DNA from hydroxyl radical-induced strand cleavage. The findings of the present study suggest that EZZ possess certain antioxidant activity, which might help to prevent occurrence of cancer by alleviating the oxidative stress in cells.

Enhancement of Membrane Durability in PEMFC by Fucoidan and Tannic Acid (후코이단과 탄닌산에 의한 PEMFC 고분자막의 내구성 향상)

  • Mihwa Lee;Sohyeong Oh;Cheun-Ho Chu;Young-Sook Kim;Il-Chai Na;Kwonpil Park
    • Korean Chemical Engineering Research
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    • v.61 no.1
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    • pp.45-51
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    • 2023
  • In order to improve the durability of the PEMFC(Proton Exchange Membrane Fuel Cells) polymer membrane, a radical scavenger and a support are used. In this study, the durability of membranes containing fucoidan extracted from seaweeds and tannic acid serving as a crosslinking agent is evaluated to improve chemical and physical durability. Physical durability is evaluated by measuring tensile strength, and chemical durability is measured by Fenton experiment. Membrane and electrode assembly (MEA) is prepared and mechanical and chemical durability are measured through accelerated durability evaluation in the cell. The tensile strength measurement showed that fucoidan and tannic acid can improve the mechanical durability of the membrane by improving the strain rate and yield strength. It is shown in Fenton experiment that fucoidan acts as a radical scavenger. As a result of the accelerated durability test in the unit cell, fucoidan improved both chemical and mechanical durability, increasing the accelerated durability evaluation time by 38.1% compared to the additive-free membrane. When tannic acid is added, the durability of the polymer membrane is improved by 13.9% by improving the mechanical durability.

Synthesis and Characterization of Covalently Cross-Linked SPEEK/Cs-substituted MoSiA/Ceria Composite Membranes with MoSiA for Water Electrolysis (MoSiA를 이용한 수전해용 공유가교 SPEEK/Cs-MoSiA/Ceria복합막의 제조 및 성능 연구)

  • SEO, HYUN;SONG, YU-RI;OH, YUN-SUN;MOON, SANG-BONG;CHUNG, JANG-HOON
    • Transactions of the Korean hydrogen and new energy society
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    • v.26 no.6
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    • pp.524-531
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    • 2015
  • To improve the electrochemical and mechanical characteristics, engineering plastic of the sulfonated polyether ether ketone (SPEEK) as polymer matrix was prepared in the sulfonation reaction of polyether ether ketone (PEEK). The SPEEK organic-inorganic blended composite membranes were prepared by sol-gel casting method. It was loaded with the highly dispersed ceria and cesium-substituted molybdosilicic acid (Cs-MoSiA) and 1,4-diiodobutane which was cross-linking agent contents of $10{\mu}L$. Cs-MoSiA was added to increase proton conductivity. Ceria ($CeO_2$) was used as a free radical scavenger which degrade the membrane in polymer electrolyte membrane water elctrolysis (PEMWE). In conclusion, CL-SPEEK/Cs-MoSiA/Ceria 1% composite membrane showed high proton conductivity 0.2104 S/cm at $25^{\circ}C$ which was better than Nafion 117 membrane.

Effects of Vitamin E on the Metallothionein Synthesis in Streptozotocin-induced Diabetic Rats (Streptozotocin유발 당뇨쥐에 있어서 Metallothionein 합성에 미치는 비타민 E의 영향)

  • 이순재;최원경
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.24 no.2
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    • pp.183-194
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    • 1995
  • The purpose of this study was to investigate the effect of vitamin E on the synthesis of the metallothionein in the liver of streptozotocin (STZ)-induced diabetic rats. Sprague-Dawley male rats($220{\pm}10mg$) were randomly assigned to one control and three STZ-diabetic groups. Diabetic groups were classified to STZ-0E(vitamine E free diet), STZ-40E(40mg vitamin E/kg of diet) and STZ-400E(400mg vitamin E/kg of diet) according to the level of vitamin E supplementation. Blood glucose levels of STZ-diabetic rats were three times higher than that of control. The contents of vitamin E in liver were lower signifciantly STZ-0E, STZ-40E groups by 50%, 36% compared with that of control. Lipid peroxide values(LPO) in liver were higher 5.6 and 2.5 times in STZ-0E and STZ-40E groups than that of control. Plasma cortisol levels were higher STZ-0E and STZ-40E groups compared with those of control, but cortisol levels were lower significantly in STZ-400E group compared with those of the STZ-0E and the STZ-40E groups. The plasma insulin levels were lower in all three STZ-diabetic group compared with that of control, but were not affected by the level of dietary vitamin E. The metallothionein (MT) contents in liver, kidney and small intestine were five times higher in STZ-0E, STZ-40E and STZ-400E compared with that of control, but STZ-400E group was lower in the MT contents in tissues compared with that of STZ-40E group. Zn-MT peak in STZ-diabetic rats liver increased than that of control by Sephadex G-75, and Zn-MT peak divided into MTI and MTII peaks by DEAE Sephadex A-25 column chromatography. The present results indicate that STZ-induced diabetic rats are more sensitive to oxidative stress, leading to the acceleration of lipid peroxidation process, which can be more promoted low level of dietary vitamin E. And the result may that increase synthesis of MT induced in the liver of diabetic rats increased so it can be sure that the diabetes is one of the MT induce factor by free radical generation. And high vitamin E supplementation reduced total MT contents of liver, kidney and small intestine and the peak of purified Zn-MT. Through the results of these experiments, we can conclude that MT might be the free radical scavenger.

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Antioxidative and Protective Effects of Haeganjeon Extract on Oxidative Damage of Hepatocytes (해간전(解肝煎)의 항산화(抗酸化) 활성(活性) 및 간세포(肝細胞)의 산화적(酸化的) 손상(損傷)에 대한 보호효과(保護效果))

  • Ahn Byung-Tae;Kim Jong-Dae;Moon Jin-Young
    • Herbal Formula Science
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    • v.10 no.2
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    • pp.127-141
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    • 2002
  • Objectives: Haeganjeon(HGJ) has been used for the treatment of liver disease in traditional medicine. The present study was carried out to evaluate the antioxidant and protective effects of HGJ extract on oxidative damage of hepatocytes by tert-butyl hydroperoxide(t-BHP). Methods: In the linoleic acid water-alcohol system, the levels of lipid peroxide(LPO) were determined by TBA method. The scavenging effect of HGJ on ${\alpha},{\alpha}-diphenyl-{\beta}-picrylhydrazyl$(DPPH) radical was determined according to the method of Hatano. In the Fenton system(ferrous ion reaction with hydrogen peroxide), the levels of hydroxyl radical induced LPO in rat liver homogenate were determined according to the method of TBA. Inhibitory effect of HGJ on superoxide generation was measured by xanthine-xanthine oxidase system. In order to evaluate antioxidative activity of HGJ in the liver cell, cultured normal rat liver cells(Ac2F) were prepared and incubated with or without HGJ. After 18hr, cells placed in DMEM medium without serum, and then incubated with 1mM tert-butyl hydroperoxide(t-BHP) for 2hrs. Viable cells were detected by MTT assay. Conclusions: In the linoleic acid autoxidation system, HGJ extract significantly inhibited the time course of the lipid peroxidation. These effects were similar to those of BHA HGJ extracts showed about 70% scavenging effect on DPPH radical. And HGJ extract inhibited the lipid peroxide formation in rat liver homogenate induced by hydroxyl radical derived from Fenton system. In addition, HGJ extract protected the cell death induced by t-BHP and significantly increased cell viability in the normal rat liver cell. These result indicated that HGJ extract might playa protective role against oxidative hepatic cell injury by means of free radical scavenger.

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