• Title/Summary/Keyword: Free radical mechanism

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Antioxidant and Whitening Effects of Agrimonia pilosa Ledeb Water Extract (짚신나물 물 추출물의 항산화 활성 및 미백효과에 관한 연구)

  • Kim, Tae-Hyuk;Kim, Jeong-Mi;Baek, Jong-Mi;Kim, Tae-Woo;Kim, Dae-Jung;Park, Jeong-Hae;Choe, Myeon
    • Korean Journal of Medicinal Crop Science
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    • v.19 no.3
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    • pp.177-184
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    • 2011
  • This study was performed to assess the antioxidant activities and whitening effects of Agrimonia pilosa Ledeb on melanin synthesis. The whitening effects of Agrimonia pilosa Ledeb water extracts were examined by in vitro mushroom tyrosinase assay and B16BL6 melanoma cells. We assessed inhibitory effect of Agrimonia pilosa Ledeb water extract on expression of melanogenic enzyme proteins including tyrosinase, tyrosinase-related protein 1 (TRP-1) and tyrosinase-related protein 2 (TRP-2) in B16BL6 cells. Inhibitory effect of Agrimonia pilosa Ledeb onto free radical generation was determined by measuring DPPH and hydroxyl radical scavenging activitie. Our results indicated that Agrimonia pilosa Ledeb water extract effectively inhibited free radical generation. In DPPH and hydroxy radical scavenging activity, Agrimonia pilosa Ledeb water extract had a potent anti-oxidant activity in a dose-dependent manner. They significantly inhibited tyrosinase activity in vitro and in B16BL6 melanoma cells. Also, Agrimonia pilosa Ledeb suppressed the expression of tyrosinase in B16BL6 melanoma cells. These results show that Agrimonia pilosa Ledeb inhibited melanin production on the melanogenesis. The underlying mechanism of Agrimonia pilosa Ledeb on whitening activity may be due to the inhibition of tyrosinase activity. We suggest that Agrimonia pilosa Ledeb may be useful as new natural active ingredients for antioxidant and whitening cosmetics.

The Effect of Zinc Levels on Free Radical Generating System in Cadmium Treated Rats (아연수준이 카드뮴을 투여한 흰쥐의 항산화 효소게에 미치는 영향)

  • 조수열;김명주;이미경
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.23 no.5
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    • pp.725-730
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    • 1994
  • This study was conducted to investigate the effect of dietary zinc (Zn) and/or cadmium (Cd) on hepatic microsomal and cytosol enzyme activities. Male Spraque-Dawley rats (110$\pm$10g ) received zinc (0, 30 and 300 ppm/) and Cd-treated groups were administered oral intubation with Cd chloride (5.0mg/kg of body weight 0 at the same time once a week. The effect of Cd on the activity of hepatic cytochromep-450 , xanthine oxidase(X. O) and superoxide dismutase (SOd) was studied in rats. Cd oral intubation resulted in a decrease in cytochrome P-450 content and SOD activity whereas a significant increase in the X.O. activity was observed was observed . Intake of excessive Zn led to an increased activity of microsomal alcohol dehydrogenase (ADH) , whereas Zn deficiency group led to a decreased group. The mechanism by which Zn induces the decreasing of Cd toxicity in rats, seems to rely on the protection of the enzyme systems P-450, ADH, aldehyde dehydrogenase (ALDH) and X.O. in the liver, possibly by forming non-toxic Cd metallothionein. These results indicate that Zn and Cd regulation might occur via inhibitory protein component of the $H_2O$$_2$ -generator system.

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Underlying mechanism of antioxidant action of Haejohwan in thyroxine-induced hyperthyroid rats (해조환(海藻丸)이 갑상선(甲狀腺) 기능항진증(機能亢進症)에서 항산화(抗酸化) 효과(效果)에 미치는 영향(影響))

  • Park, Jong-Hyuck;Yoon, Cheol-Ho;Seo, Un-Kyo;Kang, Jeong-Jun;Seo, Jong-Eun;Shin, Uk-Seob;Jeong, Ji-Cheon
    • The Journal of Internal Korean Medicine
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    • v.21 no.3
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    • pp.399-407
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    • 2000
  • This study was carried out to examine if Haejohwan (HJ) inhibits oxidant-induced lipid peroxidation and therby produces protective effect against thyroxine-induced hyperthyroid rats. Triiodothyronine $(T_3)$, thyroxine $(T_4)$, lipid peroxidation, xathine oxidase activities and type conversion ratio were increased in thyroxine treated group. However, they were decreased in HJ extract's pre-applied group. Glutathione level, activities of glutathione peroxidase, glutathione Stransferase and glutathione reductase were decreased in thyroxine treated group. But, they were increased in HJ extract's pre-applied group. These results suggest that in thyroxine-induced hyperthyroid rats HJhas an increase in the activities of oxygen free radical scavenging enzymes and inhibition of xanthine oxidase activities, and prevents lipid peroxidation.

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Mechanism of antiulceric effect of eupatilin, a biological active component of Arternisia extract

  • Miwon Son;Oh, Tae-Young;Ryu, Byung-Kweon;Moohi Yoo;Kim, Won-Bae;Junnick Yang;Lee, Eun-Bang
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.04a
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    • pp.198-198
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    • 1996
  • Eupatilin은 급성위궤양 모델인 HCl-EtOH model에서 0.3mg/kg에서 50% 억제하였으며 10mg/kg에서 95% 최대효과를 나타내었고, indomethacin model에서는 0.8mg/kg에서 50% 억제하였으며, 10mg/kg에서 97% 최대억제효과를 나타내었다. Cyclooxygenase-1의 활성은 1.7, 5.8$\mu\textrm{g}$/$m\ell$에서 prostaglandin E$_2$와 prostacyclin의 생성을 각각 2배 촉진시켰으나, cyclooxygenase-2에 대한 활성에는 영향을 주지 않았다. FMLP로 활성화시킨 호중구에 대한 활성은 0.6$\mu\textrm{g}$/kg에서 50% 억제하여 oxygen free radical 소거활성을 나타내었고, 반면 xanthine oxidase 및 iron-dependant lipid peroxidation 활성에 대해서는 78.8, 26.9$\mu\textrm{g}$/$m\ell$에서50% 억제를 보였다. 5-lipooxygenase 활성은 2.1$\mu\textrm{g}$/$m\ell$ 에서 염증매개인자인 leukotriene B$_4$ 생성을 50% 억제하였다. 이상의 결과로부터 애엽추출의 항궤양 효과는 prostaglandin의 생성촉진 및 oxygen free radical 과 leukotriene B4와 같은 공격인자의 생성억제 등의 복합적인 작용에 기인하는 것으로 생각된다.

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Effect of the Rosa rugosa Extract on the Rat with the Alcohol-salicylate-induced Gastropathy (위액분비 및 실험적 위손상에 대한 해당근 엑기스의 효과)

  • Park, Hee-Juhn;Lim, Sang-Cheol;Kim, Dong-Hoon;Lee, Jeung-Hee;Kang, He-Ok;Choi, Jong-Won
    • Korean Journal of Pharmacognosy
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    • v.36 no.1 s.140
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    • pp.38-43
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    • 2005
  • This study was undertaken to evaluate the gastrotherapeutic effects of the extract of Rosa rugosa. It can be regarded that the antigastric and anti-ulcerative effect of Rosa rugosa is originated from the reduction of total acid output identified by gastric secretion test. To clarify the protective mechanism of the Rosa rugosa extract, the gastropathy was induced in rats with alcohol-salicylate and the activities of the free radical scavenging enzymes were examined. The acitivity of superoxide dismutase and glutathione peroxide were significantly increased and the total content of glutathione was recovered. We concluded that the protective effect of the extract of Rosa rugosa on gastropathy in rats is its ability increased the activities of the free radical scavenging enzymes.

Excimer Studies on Copolymer of Styrene-Acrylic Acid (스티렌-아크릴산 공중합체의 들뜬이합체 연구)

  • Lee, Yeon Hui;Gang, Seong Cheol;Kim, Gang Jin
    • Journal of the Korean Chemical Society
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    • v.34 no.1
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    • pp.91-97
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    • 1990
  • Copolymers (PSAA) of styrene-acrylic acid were prepared through a free radical mechanism using azobisisobutyronitrile as an initiator. The fluorescence emission spectra of PSAA and the styrene-acrylic acid copolymers complexed with $Eu^{3+}$ (PSAA-Eu) were studied. The excimer fluorescence, centered at 330 nm, increases when the styrene mole fraction increases. Since the excimer fluorescence intensities of PSAA-EU, PSAA-Tb and PSAA-Eu-Tb were almost same, it appears that the kind of metal ion does not affect the excimer fluorescence. An interpretation of the results which takes into account the statistical composition of the copolymers, indicates that energy migration can occur from isolated to non-isolated styrene units.

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Antioxidative and Anti-inflammatory Effects of Aurantii Fructus Immaturus Pharmacopuncture (지각 약침액의 항산화 및 항염증 효과에 관한 연구)

  • Kim, Sung-Jin;Park, Sang-Kyun
    • Korean Journal of Acupuncture
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    • v.27 no.2
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    • pp.13-24
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    • 2010
  • Objectives : Ulcerative colitis is a chronic relapsing inflammatory disease in the gastrointestinal tract. We investigated whether Aurantii fructus immaturus (AFI) pharmacopuncture has antioxidative and anti-inflammatory effects. Methods : in vitro experiments, 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging activity, superoxide dismutase (SOD) activity, prevention on $H_2O_2$-induced cell death in RAW264.7 cell line, DNA fragmentation, and cyclooxygenase-2 mRNA expression induced by lipopolysaccharide (LPS), were analyzed to investigate antioxidative and anti-inflammatory effect of AFI pharmacopuncture. in vivo experiment, a murine model of dextran sulfate sodium (DSS)-induced colitis was used to examine the effect of AFI pharmacopuncture on CV12 at different doses of 5 ${\mu}l$, 0.5 ${\mu}l$, 0.05 ${\mu}l$ for 10 days. Body weight, colon length and macroscopic features were investigated. Results : AFI pharmacopuncture showed DPPH free radical scavenging and SOD active effects in a dose-dependent manner. AFI pharmacopuncture showed a protective effect against $H_2O_2$-induced cell injury and also attenuated LPS-induced COX-2 mRNA expression. In a DSS- induced colitis murine model, however, AFI pharmacopuncture at CV12 had no anti-inflammatory effects. Conclusions : The present results suggest that AFI pharmacopuncture extract may have anti- inflammatory and antioxidative effects in vivo test, but further research on the underlying mechanism is required.

Comparative Analysis of the Three Classes of Archaeal and Bacterial Ribonucleotide Reductase from Evolutionary Perspective

  • Pangare, Meenal G.;Chandra, Sathees B.
    • Genomics & Informatics
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    • v.8 no.4
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    • pp.170-176
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    • 2010
  • The Ribonucleotide reductases (RNR) are essential enzymes that catalyze the conversion of nucleotides to deoxynucleotides in DNA replication and repair in all living organisms. The RNRs operate by a free radical mechanism but differ in the composition of subunit, cofactor required and regulation by allostery. Based on these differences the RNRs are classified into three classesclass I, class II and class III which depend on oxygen, adenosylcobalamin and S-adenosylmethionine with an iron sulfur cluster respectively for radical generation. In this article thirty seven sequences belonging to each of the three classes of RNR were analyzed by using various tools of bioinformatics. Phylogenetic analysis, dot-plot comparisons and motif analysis was done to identify a number of differences in the three classes of RNRs. In this research article, we have attempted to decipher evolutionary relationship between the three classes of RNR by using bioinformatics approach.

Reducing effects of taurine on organ toxicity of paraquat

  • Lee, Jeong-Hun;Young, Choung-Se
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.04a
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    • pp.231-231
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    • 1996
  • Paraquat(1.1'-dimethyl-4,4'-bipyridinium ion, PQ)는 전세계적으로 가장 많이 사용되고 있는 농약으로 자살 또는 실수로 마시는 경우 예외없이 폐독성으로 사망하게 된다. 하지만 아직까지 임상에 사용되어지고 있는 효과적인 독성 경감제는 전무한 실정이다. 현재까지 밝혀진 paraquat의 주된 독성기전은 NADPH Cytochrome P$_{450}$ reductase에 의해 산화,환원 반응을 거치는 동안 free radical을 생성하여 세포막에 지질과산화를 일으켜서 세포막의 기능상실과 cell death를 일으킨다고 보고되고 있다. 따라서 본 연구에서는 항산화작용이 뛰어난 아미노산인 taurine(TA)의 radical scarvenging 효과에 의한 PQ 독성경감효과를 in vivo에서 검색하였고, in vitro에서 TA의 PQ 독성경감 mechanism을 밝히고자 하였다. in vivo에서 PQ의 간독성(s-GOT,s-GPT), 신장독성(BUN, Creatinine), 폐 및 전신독성(ALP, MDA, G-6-phosphatase)의 정도를 혈액 및 조직균질액 중에서 검색함으로써 TA의 독성억제효과를 측정하였다.

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Aggregation of α-Synuclein Induced by Oxidized Catecholamines as a Potential Mechanism of Lewy Body

  • Kim, Kyung-Sik;Kang, Jung-Hoon
    • Bulletin of the Korean Chemical Society
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    • v.26 no.8
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    • pp.1255-1259
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    • 2005
  • Lewy bodies (LBs) are neuronal inclusions that are closely related to Parkinson's disease (PD). The filamentous component of LB from patients with PD contains biochemically altered $\alpha$-synuclein. We have investigated the effect of the oxidized products of catecholamines on the modification of $\alpha$-synuclein. When $\alpha$-synuclein was incubated with the oxidized 3,4-dihydroxyphenylalanine (L-DOPA) or dopamine, the protein was induced to be aggregated. The oxidized catecholamine-mediated $\alpha$-synuclein aggregation was enhanced by copper ion. Radical scavengers, azide and N-acetyl cysteine significantly prevented the oxidized catecholamine-mediated $\alpha$-synuclein aggregation. The results suggest that free radical may play a role in $\alpha$-synuclein aggregation. Exposure of $\alpha$-synuclein to the oxidized products of catecholamines led to the formation of dityrosine. Antioxidant dipeptides carnosine, homocarnosine and anserine significantly protected $\alpha$-synuclein from the aggregation induced by the oxidized products of catecholamines.