• Journal of Life Science
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• v.17 no.2 s.82
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• pp.230-234
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• 2007

Oxygen is required for many important aerobic cellular reactions, it may undergo electrontransfer reactions, which generate highly reactive membrane-toxic intermediates (reactive oxygen species, ROS), such as hydrogen peroxide, singlet oxygen, superoxide radical, hydroxyl radical, hydroperoxyl radical, hydroxy ion. Various mechanisms are available to protect cells against damage caused by oxidative free radicals, including scavenging enzyme systems such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). This antioxidant defense system is a very complex and finely tuned system consisting of enzymes capable of detoxifying oxygen radicals as well as low molecular weight antioxidants. In addition, repair and turnover processes help to minimize subcellular damage resulting from free radical attack. $H_2O_2$,one of the major ROS, is produced at a high rate as a product of normal aerobic metabolism. The primary cellular enzymatic defense systems against $H_2O_2$ are the glutathione redox cycle and catalase. From Northern blot analysis of total RNAs from cultured cell with $H_2O_2$ treatment, various results were obtained. Expression of Cu/Zn SOD decreased when cell passage increased, but the level of the Cu/Zn SOD was scarcely expressed in 35 passage.

• Journal of Oriental Neuropsychiatry
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• v.10 no.2
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• pp.1-27
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• 1999

For experimental studies on the anticonvulsion effect and it was measured in mice that toxigenic effect, influence on the central nervous system, anticonvulsion effect, mechanism of anticonvulsion effect by change of GABA level and glutamic acid in brain, effect of the creation and degradation system of brain oxygen free radicals in convulsion. The results were obtained as follows: 1. Samulanshintang was perfect medicine without toxigenic effect. 2. Pretreatment of Samulanshintang did not influence on the central nervous system. 3. Pretreatment of Samulanshintang did not influence on maximal electric seizure(MES), strychnine, bicuculine and picrotoxin, but pentylenetrazol(PTZ)-induced convulsion significantly decreased. 4. Effect of Samulanshintang except for Jinsa on the PTZ-Induced convulsion decreased. 5. Effect of Samulanshintang fragrance(SMATF) and Samulanshintang distiled water(SMATW) on the PTZ-induced convulsion did not influence. 6. Decrease of brain GABA level in PTZ-induced convulsion was increased by pretreatment of Samulanshintang. 7. Decrease of brain glutathione content in PTZ-induced convulsion was increased by pretreatment of Samu- lanshintang. 8. GABA-T activity increased by PTZ-induced was controlled by the pretreatment of Samulanshintang. 9. Increase of brain lipid peroxide content in PTZ-induced convulsion was decreased by pretreatment of Samulanshintang. 10. Significant increase of brain xanthine oxidase and aldehyde oxidase activities in PTZ-induced was controlled by pretreatment of Samulanshintang. 11. Decrease of brain superoxide dismutase(SOD), catalase and glutathione peroxidase activities in PTZ-induced was decreased by pretreatment of Samulanshintang. From the above results, Samulanshintang was perfect medicine without toxigenic effect and was recognized anticonvulsion effect by decreasing brain glutamic acid level and increasing brain GABA level. Samulanshintang have an effect on creation and degradation system of brain oxygen free radicals in convulsion, thus it was considered that Samulanshintang could be applied in convulsive disorder as epilepsy, febrile seizure and spasm etc.

• Korean Journal of Environmental Biology
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• v.27 no.2
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• pp.230-236
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• 2009

An extract of Allomyrina dichotoma larva (ADL), one of the insects used most frequently in traditional Chinese medicine for the treatment of liver diseases such as hepatocirrhosis and hepatofibrosis, was assessed for antioxidant bioactivity in this study. In the current work, we have investigated the protective effects of ADL extracts on tert-butyl hydroperoxide (t-BHP)-induced hepatotoxicity in cultured hepa1c1c7 cells and in the mouse liver. The treatment of the hepa1c1c7 cells with ADL extracts induced a significant reduction of t-BHP-induced oxidative injuries, as determined by cell cytotoxicity, lipid peroxidation (LPO) and reactive oxygen species contents, in a dose-dependent manner. Moreover, ADL extracts evidenced a protective effect against t-BHPinduced oxidative DNA damage, as revealed by the results of the Comet assay in hepa1c1c7 cells. ADL extracts also protected against hydroxyl radical-induced 2-deoxy-d-ribose degradation by ferric ion-nitrilotriacetic acid and $H_2O_2$. In addition, ADL extracts were shown to be able to quench 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. Our in vivo study revealed that ADL extracts pretreatment applied prior to t-BHP administration significantly prevented an increase in the serum levels of hepatic enzyme markers and reduced LPO in the mouse liver in a dose-dependent manner. Taken together, these results suggest that the protective effects of ADL extracts against t-BHP-induced hepatotoxicity may be attributable, at least in part, to its ability to scavenge free oxygen radicals, and to protect against DNA damage due to oxidative stress.

• The Korean Journal of Pharmacology
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• v.32 no.2
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• pp.259-267
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• 1996

In an attempt to dofine the early biochemical determinants that participate in the pathogenesis of glycerol-induced nephrotoxicity, especially focusing on oxygen free radicals and $N-acetyl-{\beta}-D-glucosaminidase$ (NAG) activity, we studied 24-hours urine outflow, 24-hours urinary protein excretion and urinary NAG activity after the injection of glycerol and also we studied malondialdehyde(MDA) level and superoxide dismutase(SOD) activity in the kidney of rats at 24hr after the injection of glycerol. Sprague-Dawley albino rats weighing 240 to 260 gm were injected intramuscularly with a 50% solution of glycerol(2ml/kg, 4ml/kg and 8ml/kg). The group treated with glycerol showed significantly lower urine outflow level and urinary protein excretion level and higher urinary NAG activity after the injection as compared to those of control group. Also the group treated with glycerol showed significantly higher MDA level and lower SOD activity at 24hr after the injection as compared to those of control group. These results suggest that the excessive oxygen free radicals resulting from the depression of SOD activity is an important determinant in the pathogenesis of glycerol-induced nephrotoxicity and higher urinary NAG activity is an index of renal tubular cell damage in the glycerol-induced nephrotoxicity.

• Journal of Acupuncture Research
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• v.18 no.2
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• pp.150-160
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• 2001

Objectives ; This study was undertaken to determine whether Carthami-Flos aquacapuncture (CFA) exerts protective effect against oxidant-induced inhibition of $Na^+-K^+$-ATPase activity in cerebral synaptosomes. Methods and Results ; The enzyme activity was dependent on incubation time and enzyme protein concentrations. An oxidant t-butylhydroperoxide (tBHP) at 1 mM concentration caused a significant inhibition of $Na^+-K^+$-ATPase activity, which was prevented by addition of 0.01% CFA. tBHP inhibition and CFA protection were independent on incubation time or enzyme protein concentrations. The enzyme activity was increased by ATP in a dose dependent manner. Effects of tBHP and CFA were not affected by ATP cocentrations. tBHP (1 mM) produced a significant increase in lipid peroxidation in cerebral synaptosomes, which was prevented by 0.01% CFA. CFA decreased oxygen free radicals generated induced by the phorbol-ester in a dose-dependent manner in human neutrophil. Conclusions ; These results suggest that CFA exerts protective effect against tBHP-induced inhibition of $Na^+-K^+$-ATPase activity, which is due to by an antioxidant action resulting from a direct scavenging effect of oxygen free radicals in the cerebral synaptosomes.

• Elastomers and Composites
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• v.55 no.1
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• pp.51-58
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• 2020

In this study, the thermal oxidation of raw natural rubber (NR) was investigated under controlled conditions by optical image and fourier transform infrared (FT-IR) analysis. The thermal oxidation was performed on a transparent thin film of raw NR coated on a KBr window in a dark chamber at 80℃ under low humidity conditions to completely exclude moisture and restrict light oxidation. Images of the thin film of raw NR were obtained before and after thermal oxidation. FT-IR absorption spectra were measured in the transmission mode at different thermal exposure times. The thermal oxidation of NR was examined by the changes in the absorption peaks at 3449, 1736, 1447, 1377, 1242, 1072, and 833 cm^-1, which corresponded to a hydroxyl group (-OH), a carbonyl group (-C=O) from an aldehyde and a ketone, a methylene group (-CH₂-), a methyl group (-CH₃), a carbon-oxygen single bond (-C-O) from an epoxide, a carbon-oxygen bond (-C-O) from an ether, an alcohol, a peroxide, or a cyclic peroxide, and a cis-methine group (cis-CCH₃=CH-), respectively. In the initial stage of thermal oxidation, two different types of free radicals were produced quickly and randomly by the homolytic cleavage of a double bond and allylic hydrogen abstraction. Aldehydes and ketones were formed from chain scissions of the double bonds and alcohols were produced from allylic hydrogen abstraction at the methylene or methyl groups. Two reactions seemed to proceed competitively with each other. At a later stage, oxidative crosslinks seemed to dominate through the combination of free radicals such as an allyl radical (CH=CHCH₂·), alkoxy radical (RO·), and peroxy radical (ROO·) and the reaction of a hydroperoxide (-ROOH) with a double bond. The image obtained after thermal oxidation showed hardening without cracks. Based on these observations, a plausible two-step mechanism was suggested for chain hardening caused by the thermal oxidation.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.9
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• pp.1330-1335
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• 2005

Red brownish p-pheylenediamine (PPD) has been widely used hair dye for women. The dye was known to cause systemic anaphylaxis, dermatitis and bladder cancer. But the effect of PPD toxicity with oxygen free radical has not been studied. This study investigated the degree of skin injury by PPD. PPD ($2.5\%$ PPD in $2\%\;NH_{4}OH$) was applied to the rat skin ($25 mg/16.5\;cm^2$) 3 or 5 times every other day. Histopathological findings demonstrated the proliferation of epithelial cells and the increased keratinization by PPD. The activities of glucose 6-phosphatase (G6Pase) was decreased and acid phosphatase (ACP) was increased in PPD-applied rat skin. Groups in which PPD was applied 5 times were more damaged than groups applied 3 times. To examine the relationship between tissue damage and oxygen free radicals, effect of PPD on xanthine oxidase (XO) activity was measured and XO activity was more significantly increased in the group treated with PPD 5 times than 3 times. However, reduced glutathione (GSH) content, and the activities of catalase (CAT), super-oxide dismutase (SOD) and glutathione S -transferase (GST) were more decreased in PPD-applied groups than in controls. Even though the activities of XOD was not changed in the group treated with PPD 3 times, the decreased activities of oxygen free radical system and the damaged skin tissue were observed. This result might be caused by the production of toxic PPD metabolites in rat skin. In conclusion, topical PPD application led to skin injury in a dose-dependent manner, probably due to the generation rate of oxygen free radical.

• Toxicological Research
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• v.16 no.1
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• pp.1-8
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• 2000

Astrocytes generate free radicals including nitric oxide (NO) and reactive oxygen intermediates(ROI) which in turn play roles in the pathogenesis of degenerative diseases and sclerotic changes of the brain. This study was designed to evaluate the mechanism that free radicals contribute to the cytotoxicty of rat neonatal primary astrocytes. Treatment with NO donors alone including soldium nitroprusside(SNP), S-nitrosoglucathinoe (GSNO), and S-nitroso-n-acetylpenicillamine (SNAP) showed a little effect on the death of rat neonatal primary astrocytes, whereas SNP markedly induced the death of RAW 264.7 cells. ROI inculding H2O2 and O2 donor also slightly induced the death of rat primary astrocytes. However, 3-morpholinosydnonimine(SIN-1), a donor of peroxynitrite (ONOO), which is a reactive compound of NO with superoxide, significantly decreased the viability of rat primary astrocytes in a dose-dependent manner. Cells were retarded in outgrowth of viability of cellular processes with cell shrinkage and detachment from culture dishes. Hoechst staining demonstrated that SIN-1-induced cell death might be due to an apoptosis which was characterized by nuclear condensation and fragmentation. SIN-1-induced apoptosis was prevented by the pretreatment with superoxide dismutase (SOD) and catalase in rat primary astorocytes. Furthermore, prevention of the generation of reduced glutathione (GSH) by DL-buthionine-[S, R]-sulfoximine (BSO) aggravated the cytotoxic effects of SNP, benzene triol, and SIN-1 in rat primary astrocytes. Taken together, it is suggested that peroxynitrite may be a major effector of apoptosis and cellular antioxidant system is important for cell survival in rat prima교 astrocytes.

• 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.