• Title/Summary/Keyword: Radical mechanism

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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.

Synthesis of New pH-Sensitive Amphiphilic Block Copolymers and Study for the Micellization Using a Fluorescence Probe

  • Kim, Kyung-Min;Choi, Song-Yee;Jeon, Hee-Jeong;Lee, Jae-Yeol;Choo, Dong-Joon;Kim, Jung-Ahn;Kang, Yong-Soo;Yoo, Hyun-Oh
    • Macromolecular Research
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    • v.16 no.2
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    • pp.169-177
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    • 2008
  • This paper reports a facile synthesis of new water-soluble poly(ethylene oxide) (PEO)-based amphiphilic block copolymers showing pH sensitive phase transition behaviors. The copolymers were prepared by atom transfer radical polymerization (ATRP) of methacrylamide type of monomers carrying a sulfonamide group using a PEO-based macroinitiator and a Cu(I)Br/$Me_6TREN$ catalytic system in aqueous media. The resulting polymers were characterized by a combination of $^1H$-NMR, size exclusion chromatography, and UV/Visible spectrophotometeric analysis. The micellization of the block copolymers as a drug-loading mechanism in aqueous media using fluorescein salt was examined as a function of pH. The stable micelle formation and its loading efficacy suggest that the block copolymers can be used as precursors for drug-nanocontainers.

Antioxidant Activities and the Effect of Reducing Serum Alcohol Concentration of Lentinus edodes (표고버섯의 항산화능과 알코올분해능에 미치는 영향)

  • Kim, Chae-Hyun;Jeong, Jong-Gil
    • The Korea Journal of Herbology
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    • v.24 no.4
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    • pp.159-164
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    • 2009
  • Objectives : The purpose of this study is to evaluate antioxidant activities and reducing serum alcohol concentration of extract of Lentinus edodes on the alcohol administered rats. Methods : Antioxidant effect was measured by total phenolic compound and DPPH-radical scavenging activity of extract of Lentinus edodes in vitro. Blood alcohol concentration, aldehyde concentration, malondialdehyde concentration, glutathion concentration were measured in vivo. Results : The extract of Lentinus edodes increased DPPH-radical scavenging activity dose-dependently. The water extract with boiling water showed lower antioxidant activity and phenolic content than 70% ethanol extract in vitro. Blood alcohol concentration was significantly reduced by pre-treatment of ethanol extract of Lentinus edodes. The effect was more significant than commercial product used as a positive control. Conclusions : This study suggest that Lentinus edodes can be a potential nature resource for the management of ethanol toxicity although the mechanism of action involved in the treatment remains to be explored.

The Role of Reactive Oxygen Free Radical in the Pathogenetic Mechanism of Endotoxin-Induced Acute Lung Injury in Domestic Pigs (내독소에 의한 돼지의 급성 폐손상에서 산소기의 역할에 관한 연구)

  • Kim, Young-Whan;Yoo, Chul-Gyu;Jeong, Ki-Ho;Choi, Hyung-Seok;Lee, Hyuk-Pyo;Han, Sung-Koo;Shim, Young-Soo;Kim, Keun-Youl;Han, Yong-Chol
    • Tuberculosis and Respiratory Diseases
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    • v.38 no.4
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    • pp.357-371
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    • 1991
  • To identify the pathogenetic role of reactive oxygen free radical-induced oxidation reaction in endotoxin-induced acute lung injury, we infused endotoxin into 8 domestic pigs; endotoxin only (n=3), pretreatment with dimethylthiourea (DMTU) (n=5). We observed the sequential changes in hemodynamic parameters, the concentration of plasma oxidized glutathione (GSSG) in pulmonary arterial and venous blood, and albumin content in bronchoalveolar lavage fluid (BALF). The results were as follows. 1) While cardiac output decreased, mean pulmonary arterial pressure, pulmonary vascular resistance, and alveolar-arterial oxygen difference increased over phase 1 (0-2 hr) and phase 2 (2-4.5 hr) by endotoxin, DMTU attenuated the above changes only during phase 2. 2) While the concentration of plasma GSSG increased significantly by endotoxin during phase 2, there were no significant differences between pulmonary arterial and venous GSSG contents during both phases. The increase in plasma GSSG content was attenuated by DMTU. 3) The content of BALF albumin was significantly lower in DMTU group than that of endotoxin group. These results suggest that reactive oxygen free radical-induced oxidation reaction may have an important pathogenetic role in endotoxin-induced acute lung injury in pigs, which seems to be greater during phase 2 rather than phase 1.

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Conversion of Myocardial Xanthine Oxidase in Ischemic Heart of Rat (허혈심근 Xanthine Oxidase 의 전환에 관한 연구)

  • 박창권
    • Journal of Chest Surgery
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    • v.21 no.5
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    • pp.803-815
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    • 1988
  • The present experiments were performed to confirm the hypothesis that xanthine oxidase[XOD], as a source and mechanism of oxygen radical production, plays an important role in the genesis of the reperfusion injury of ischemic myocardium. The experimental ischemic-reperfusion injury was induced in isolated, Langendorff preparations of rat hearts by 60 min. Of global ischemia with aortic clamping followed by 20 min. of reperfusion with oxygenated Krebs-Henseleit solution[pH 7.4, 37*C]. The results were as follows: 1. The releases of creatine phosphokinase and a lipid peroxidation product, malondialdehyde[MDA] into the coronary effluent were abruptly increased upon reperfusion of ischemic hearts. The increases of the enzyme and MDA were suppressed significantly in the hearts removed from rats pretreated with allopurinol, a specific XOD inhibitor[20mg/kg, oral, 24 hrs and 2 hrs before study]. This effect of allopurinol was comparable to that of oxygen radical scavengers, superoxide dismutase[5, 000U] and catalase[12, 500 U]. 2. The increased SOD-inhibitable reduction of ferricytochrome C, which was infused to the hearts starting with reperfusion, was significantly suppressed in allopurinol pretreated hearts. 3. Activities of myocardial XOD were compared in the normal control hearts and the ischemic ones. Total enzyme activities were not different in both hearts. However, comparing with the control, the ischemic ones showed higher activity in 0-form and lower activities in D-form and D/O-form. 4. In the ischemic hearts, phenylmethylsulfonyl fluoride, a serine protease inhibitor, prevented significantly the increase of 0-form and the decreases of D and D/O-form, while thiol reagents did not affect the changes of the enzyme. 5. The increase of 0-form and the decreases of D and D/0-form were not significant in both calcium-free perfused and pimozide, a calmodulin inhibitor, treated ischemic hearts. 6. The SOD-inhibitable reduction of ferricytochrome C were suppressed by PMSF and pimozide treatment as well as by calcium-free perfusion. It is suggested from these results that in the ischemic rat myocardium, xanthine oxidase is converted to oxygen radical producing 0-form by calcium, calmodulin-dependent proteolysis and plays a contributing role in the genesis of ischemic-reperfusion injury by producing oxygen free radicals.

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A Gas-Phase Investigation of Oxygen-Hydrogen Exchange Reaction of O(3P) + C2H5 → H(2S) + C2H4O

  • Jang, Su-Chan;Park, Min-Jin;Choi, Jong-Ho
    • Bulletin of the Korean Chemical Society
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    • v.35 no.3
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    • pp.839-844
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    • 2014
  • The gas-phase radical-radical reaction $O(^3P)$ + $C_2H_5$ (ethyl) ${\rightarrow}$ $H(^2S)$ + $CH_3CHO$(acetaldehyde) was investigated by applying a combination of vacuum-ultraviolet laser-induced fluorescence spectroscopy in a crossed beam configuration and ab initio calculations. The two radical reactants $O(^3P)$ and $C_2H_5$ were respectively produced by photolysis of $NO_2$ and supersonic flash pyrolysis of the synthesized precursor azoethane. Doppler profile analysis of the nascent H-atom products in the Lyman-${\alpha}$ region revealed that the average translational energy of the products and the average fraction of the total available energy released as translational energy were $5.01{\pm}0.72kcalmol^{-1}$ and 6.1%, respectively. The empirical data combined with CBS-QB3 level ab initio theory and statistical calculations demonstrated that the title exchange reaction is a major channel and proceeds via an addition-elimination mechanism through the formation of a short-lived, dynamical addition complex on the doublet potential energy surface. On the basis of systematic comparison with several exchange reactions of hydrocarbon radicals, the observed small kinetic energy release can be explained in terms of the loose transition state with a product-like geometry and a small reverse activation barrier along the reaction coordinate.

Degradation Characteristic of Endocrine Disruptors (DEP, NP) Using Combined Advanced Oxidation Processes (AOPs) (혼합된 고급산화공정(AOPs)을 이용한 내분비계장애물질(DEP, NP)의 분해특성 연구)

  • Na, Seung-Min;Ahn, Yun-Gyong;Cui, Ming-Can;Cho, Sang-Hyun;Khim, Jee-Hyeong
    • Journal of Environmental Science International
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    • v.20 no.2
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    • pp.231-239
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    • 2011
  • Diethyl phthalate (DEP) and nonylphenol (NP) are widely spread in the natural environment as an endocrine disruption chemicals (EDs). Therefore, in this study, ultrasound (US) and ultraviolet (UVC), including $TiO_2$, as advanced oxidation processes (AOPs) were applied to a DEP and NP contaminated solution. When only the application of US, the optimum frequency for significant DEP degradation and a high rate of hydrogen peroxide ($H_2O_2$) formation was 283 kHz. We know that the main mechanism of DEP degradation is radical reaction and, NP can be affected by both of radical reaction and pyrolysis through only US (sonolysis) process and combined US+UVC (sonophotolysis) process. At combined AOPs (sonophotolysis/sonophotocatalysis) such as US+UVC and US+UVC+$TiO_2$, significant degradation of DEP and NP were observed. Enhancement effect of sonophotolysis and sonophotocatalysis system of DEP and NP were 1.68/1.38 and 0.99/1.17, respectively. From these results, combined sonophotocatalytic process could be more efficient system to obtain a significant DEP and NP degradation.

Protective effect of injinhotang and its components on acetaminophen-induced hepatoxicity in rats (인진호탕(茵陳蒿湯)의 조합에 따른 간 보호 효과)

  • Choi, Jae-Woo;Bae, Chang-Wook;Park, So-Young;Yun, Hyun-Joung;Park, Sun-Dong
    • Herbal Formula Science
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    • v.13 no.1
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    • pp.9-33
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    • 2005
  • Acetaminophen, which causes acute liver min in humans and animals, has made useful inducer of hepatoxicity for studying hepatopreventive drugs. Injinhotang is known as one of the hepatopreventive drugs. However, its mechanism of recovery of hepatoxicity treated with acetaminophen is poorly understood. this study was performed to observe the antioxidative effect of injinhotang extract and its several combination groups. The results were obtained as follows:1. In the study on free radical scavenging effect in vitro(the suppressing effect on peroxidation of linoleic acid on concentration, the scavenging effect of DPPH radical, inhibitory effect of superoxide in xanthine-xanthine oxidase system and the inhibitory effect on lipid peroxidation reaction by hydroxy radical in H2O2-Fe2+system, injinhotang have more effect than its components groups relatively. 2. In the study on antioxidants system in vivo(the level of serum LPO, the level of hepatic LPO, catalase, GSH, GST), only injnhotang has a significant effect. 3. In the study on hepatotoxicity(GOT, GPT, $\gamma$-GTP, ALP, LDH, b ilirubin), only injinhotang has a significant effect. These results suggest that injinhotang has the protective effect on acetaminophen-induced hepatoxicity. The mechanisms of these are supposed to be involved in antioxidant and three drugs' cooperative synergy effect.

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Study on the Effect of Gamigehyuldeung-tang on Gultamate Receptor, free Radical and Brain Damage in Rats (가미계혈등탕이 Glutamate receptor와 Free radical 및 뇌손상 보호에 미치는 영향)

  • An Jong suk;Kim Dong Hee;Kim Yun Sik;Lee Young Gu;Park Jong Ho;Namgung Uk;Seol In Chan
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.3
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    • pp.728-737
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    • 2003
  • This study was investigated to prove the effect of GMGHT on the gultamate receptor, free radical and brain damage in rats sujected to Brain Ischemia The results were as follows; 1, GMGHT showed significant inhibitory effect of GMGHT on LDH release induced by NMDA, AMPA, and kinate. 2. GMGHT showed significant inhibitory effect of GMGHT on LDH release induced by BSO and Fe/sup 2+/. 3. GMGHT decreased coma duration time in a infatal dose of KCN and showed 30% of survival rate in a fatal dose. 4. GMGHT decreased ischemic area and edema incited by the MCA blood flow block. 5. GMGHT showed improvement of forelimb and hindlimb test after MCA occulusion in neurological exemination. 6. GMGHT showed no significant change after MCA occulusion in pathological observation as normal group. These results indicate that GMGHT can be used in the brain damage sujected to Brain Ischemia. Further study will be needed about the functional mechanism and etc.

Neuroprotective Effects of Medicinal Herbs in the Transient Focal Ischemia in Rats (일시적 국부 뇌허혈 동물모델에서 한약재의 신경보호 효과)

  • Oh, Jin-Kyung;Jung, Ji-Wook;Ahn, Nam-Yoon;Oh, Hye-Rim;Cheung, Jae-Hoon;Ryu, Jong-Hoon
    • Korean Journal of Pharmacognosy
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    • v.34 no.4 s.135
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    • pp.335-338
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    • 2003
  • It is thought that highly reactive oxygen species generated after strokes plays a key role in damaging the brain. We examined free radical scavenging activity and neuroprotective effects of several medicinal herbs in a rat model of transient ischemia. Free radical scavenging property of medicinal herbs was examined in vitro using 1,1-diphenyl-2-picrylhydrazyl stable free radical. Transient ischemia was induced by intraluminal occlusion of the right middle cerebral artery for 120 min, followed by reperfusion for 22 hr in rats. Aqueous extracts of 8 medicinal herbs (200 mg/kg) were orally administered twice to transient ischemic rat prior to reperfusion and 2 hr after reperfusion. Total infarction volume in the hemisphere ipsilateral to the ischemia-reperfusion was significantly decreased in 7 groups treated with Sophora flavescens, Lycopus lucidus, Sanguisorba officinalis, Caesalpinia sappan, Albizia julibrissin, Rubia akane, Psoralea corylifolia, or Prunella vulgaris. However, neuroprotective effects of these medicinal herbs were not correlated with their antioxidative activities. These results suggest that these medicinal herbs exert neuroprotection via antioxidative as well as unknown mechanism.