• Archives of Pharmacal Research
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• 제27권3호
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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.

• Natural Product Sciences
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• 제17권4호
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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.

• 생약학회지
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• 제33권4호통권131호
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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.

• 한국자원식물학회지
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• 제27권3호
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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.

• Natural Product Sciences
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• 제10권6호
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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.

• Natural Product Sciences
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• 제10권6호
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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.

• Korean Chemical Engineering Research
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• 제61권1호
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• pp.45-51
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• 2023

PEMFC(고분자전해질 연료전지) 고분자막의 내구성을 향상시키기 위해서 라디칼 제거제와 지지체가 사용되고 있다. 본 연구에서는 화학적 내구성과 물리적 내구성을 향상시키기 위해서 해조류에서 추출한 후코이단과 가교제 역할을 하는 탄닌산을 첨가한 고분자막의 내구성을 평가하였다. 물리적 내구성은 인장강도를 측정해 확인했고, 화학적 내구성은 Fenton 실험으로 측정하였다. 막과 전극합체(MEA)를 제조하여 셀에서 가속 내구 평가를 통해 기계적 내구성과 화학적 내구성을 평가하였다. 인장강도 측정으로 후코이단과 탄닌산의 변형율과 항복강도 등을 향상시켜 고분자막의 기계적 내구성을 향상시킬 수 있음을 보였다. 후코이단이 라디칼 제거제 역할을 함을 Fenton 실험에서 확인했다. 단위전지에서 가속 내구 실험 결과 후코이단은 화학적 내구와 기계적 내구를 모두 향상시켜 무첨가막보다 가속 내구 평가 시간을 38.1% 증가시켰고, 탄닌산을 추가하면 기계적 내구성 향상에 의해 고분자막의 내구성이 13.9% 향상되었다.

• 한국수소및신에너지학회논문집
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• 제26권6호
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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.

• 한국식품영양과학회지
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• 제24권2호
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• pp.183-194
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• 1995

식이내 비타민 E 함량을 0mg vit. E/kg diet(STZ-OE군), 40mg vit. E/kg diet(STZ-40E군) 그리고 40mg vit. E/kg diet(STZ-400E군)로 달리하여 4주간 사육한 후 streptozotocin으로 당뇨병을 유발한 후 4일째에 희생시켜, 당뇨병 쥐에 있어서 MT합성에 미치는 비타민 E의 영향을 관찰한 결과는 다음과 같다. 체중증가는 STZ을 투여하기 전까지는 대조군에 비해 STZ-0E군만 낮았으나 STZ투여한 후에는 STZ투여군들 모두가 현저하게 감소하였다. 실험군간을 비교해 보면 STZ-400E군이 STZ-0E, STZ-40E군에 비해 STZ을 투여한 후 감소율이 낮았다. 혈당량은 당뇨군들이 대조군에 비해 약 3배 정도 높았으나, 당뇨군들 중에서 비타민 E의 영향은 없었다. 간조직 중의 비타민 E 함량은 STZ-0E 및 STZ-40E군에서는 대조군 보다 각각 50, 36%씩 크게 감소되었으나 STZ-400E군은 차이가 없었다. Glutathione(GSH) 함량은 비타민 E의 다량 첨가군(STZ-400E)에서 GSH 함량과 GSH/GSSG비가 증가되었다. 간조직 중의 지질과산화가는 STZ-0E군과 STZ-40E군이 대조군 보다 5.6, 2.5배씩 높았으나 STZ-400E군은 유의적인 차이가 없었다. Piasma insulin level은 대조군에 비해 당뇨유발군 모두가 현저하게 감소하였고, 비타민 E의 효과는 관찰되지 않았다. Piasma cortisol level은 대조군에 비해 STZ-0E, STZ-40E군이 증가하였으나 STZ-400E군은 이들 두군에 비해 유의적으로 감소하여 대조군 수준이었다. 간장, 신장, 소장조직의 MT 함량은 대조군에 비해 당뇨유발군이 각각 5.3, 2.8, 16배 정도 현저히 증가되었는데 STZ-400E군은 STZ-0E, STZ-40E 이들 두군에 비해 현저하게 감소되었다. Sephadex G-75를 사용하여 간조직 중의 Zn-MT를 분리한 결과 당뇨 유발군에서 대조군 보다 Zn-MT peak가 증가되었으나 Cu-MT는 변화가 없었다. Zn-MT는 DEAE A-25를 사용하여 MTI, MTII peak를 확인할 수 있었다. 이상의 결과에서 STZ유발 당뇨쥐는 산화적 stress에 더욱 감수성이 높으므로 지질과 산화 반응이 정상군에 비해 촉진되었으며, 식이 중 공급되는 비타민 E 함량이 부족시는 더욱 가속화되었다. 더불어 간조직 중의 MT합성도 같은 양상으로 증가되어 당뇨병이 free radical 생성으로 인해 MT를 유도하는 하나의 새로운 인자인 것으로 확인하였다. 그러나 식이 중 비타민 E의 다량 급여시는 생체내 항산화계 효소들이 정상군에 가깝게 활성화되고, 생리적 항산화물질이 증가되었다. 따라서 식이비타민 E가 당뇨병으로 인한 지질과산화에 대한 항산화적 방어기구를 강화시키므로써 조직의 과산화적 손상을 환화시키는데 크게 기여함을 알 수 있었다. 또한 비타민 E 다량 투여로 간조직과 신장, 소장조직내의 total MT 함량이 감소되고 분리정제한 Zn-MT의 peak가 감소하는 것으로 보아 MT가 free radical scavenger로서 작용한 것이라고 생각된다.

• 대한한의학방제학회지
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• 제10권2호
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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.