• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.4
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• pp.980-984
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• 2006

In order to examine the effect of oxygen free radicals on the vascular endothelial cells, cell viability was measured by XTT assay after bovine pulmonary vascular endothelial cell line(BPVEC) was treated only with hydrogen peroxide. In addition, the antioxidant effect of allopurinol on cells treated with hydrogen peroxide was examined by colormetric assay. in this study, the BPVEC treated with hydrogen peroxide showed the significantly decreased cell viability compared with control. Whereas, the viability of cells treated with hydrogen peroxide and allopurinol has significantly increased when compared with that of cells treated only with hydrogen peroxide. These results suggested that hydrogen peroxide, one of the oxygen free radicals showed cytotoxic effect and allopurinol has protective effect on oxygen free radical-induced cytotoxicity.

• Journal of Microbiology and Biotechnology
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• v.6 no.2
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• pp.103-109
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• 1996

Mn(II)+succinate decreased the carotenoid formation of the yeast Phaffia rhodozyma, probably by scavenging $O_2$. When duroquinone (DQ), an internal and external $O_2$ generator, was added to medium, P. rhodozyma produced more amount of carotenoids. The increased carotenoid production was destroyed by oxygen radical (OR) scavengers, ascorbate+Cu(II) and dimethylsulfoxide. When sub-lethal concentrations of $H_2O_2$ , an external OR source, and antimycin, an internal OR inducer, were used, the effect of $H_2O_2$ on carotenoid formation and composition was less significant than that of antimycin. Addition of superoxide dismutase, an external OR remover, rescued cells from death caused by the high concentration of DO. In this condition, the yeast culture showed an increase in carotenoid content. Addition of DQ into P. rhodozyma culture in the stationary phase did not increase carotenoid production. Therefore, carotenoid formation was stimulated by internal ORs in the growing yeast. It was probably due to release of catabolite repression on carotenogenesis in the yeast. Aeration was important for carotenoid production but was not as effective as the internal OR producer, DQ.

• 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.

• 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.

• Journal of Microbiology and Biotechnology
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• v.17 no.3
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• pp.445-453
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• 2007

The effect of an electrochemically generated oxidation-reduction potential and electric pulse on ethanol production and growth of Saccharomyces cerevisiae ATCC 26603 was experimented and compared with effects of electron mediators (neutral red, benzyl viologen, and thionine), chemical oxidants (hydrogen peroxide and hypochlorite), chemical reductants (sulfite and nitrite), oxygen, and hydrogen. The oxidation (anodic) and reduction (cathodic) potential and electric pulse activated ethanol production and growth, and changed the total soluble protein pattern of the test strain. Neutral red electrochemically reduced activated ethanol production and growth of the test strain, but benzyl viologen and thionine did not. Nitrite inhibited ethanol production but did not influence growth of the test strain. Hydrogen peroxide, hypochlorite, and sulfite did not influence ethanol production and growth of the test strain. Hydrogen and oxygen also did not influence the growth and ethanol production. It shows that the test strain may perceive electrochemically generated oxidation-reduction potential and electric pulse as an environmental factor.

• Journal of Korean Physical Therapy Science
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• v.8 no.1
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• pp.923-934
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• 2001

In order to investigate a pathogenesis of liver damage induced by skin burn, thermal injury was induced by scald burn on entirely dorsal surface in rats (total body surface area 30%) except for inhalated injury. At 5 and 24 h after scald bum, biochemical assay and morphological changes in skin tissue, serum and liver tissue were examined. The effects of bum injury on the levels of glutathione, lipid peroxide and on the activities of oxygen free radical generating and scavenging enzymes have been determined in association with observing of histologic and ultrastructural changes, measuring the protein concentration in plasma, and counting the number of intravascular polymorphonuclear leukocytes. The activity of xanthine oxidase, an enzyme of oxygen free radical generating system. was elevated (p<0.01) in serum, but not in skin and in liver tissue. Futhermore, thermal injury decreased not only the protein concentration in plasma but also the number of leukocytes, that indicates induction of edema formation with protein exudation and inflammation by neutrophil infiltration into the internal organs. These data suggest that acute dermal scald burn injury leads to liver damage, that is related to elevation of xanthine oxidase activity in serum. Xanthine oxidase may be a key role in the pathogenesis of liver damage induced by skin burn.

• Applied Chemistry for Engineering
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• v.8 no.1
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• pp.108-113
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• 1997

Decomposition of oxalic acid was studied in nitric acid media by using UV radiations. The UV source is Hg-lamp, emitting $2537{\AA}$ wavelength. Oxalic acid was not decomposed by itself in spite of UV radiation, but in the presence of nitric acid decomposed easily under UV radiation. It is believed that oxygen radical generated from nitrate ion by UV radiation results in the decomposition of oxalic acid. Decomposition rate of oxalic acid reached a maximum in around 0.5M $HNO_3$ and then gradually decreased with nitric acid concentration. The decrease can be also explained to be due to the reaction between oxygen radical and $NO_3{^-}$.

• Natural Product Sciences
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• v.18 no.4
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• pp.261-265
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• 2012

Xanthohumol was isolated from hops (Humulus lupulus L.), and then investigated anti-oxidant effect by AAPH-induced LLC-PK1 cell and oxygen radical absorbance capacity (ORCA) assays and MMP-12 inhibitory effect by direct MMP-12 inhibition assay. The treatment of xanthohumol protected LLC-PK1 cells from AAPH-induced cell damage such as cell viability, SOD and GSH-px reduction in a dose dependant manner (0.1, 1, and $5{\mu}M$), the SOD value was 2.98, 4.51, and 5.77 U/mg protein, and GSH-px value was 30.12, 49.32, and 60.11 U/mg protein. ORAC value of xanthohumol was showed as 4320, 12004, and $14209{\mu}M$ TE/g at the concentration 0.1, 1, and $5{\mu}M$, respectively. The change of SOD and GSH-px values was significantly correlated with the results of ORAC assay, that is, AAPH-induced cell and ORCA assays. In addition, inhibition of MMP-12 that is known to play an important role in skin aging was 14%, 37%, 46%, and 79% at the concentration of 0.01, 0.1, 1, and $5{\mu}M$, respectively. On the basis of these results, xanthohumol from hops (Humulus lupulus L.) showed interesting biological and pharmacological activity such as anti-oxidant effect and anti-aging.

• Reproductive and Developmental Biology
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• v.36 no.1
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• pp.49-53
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• 2012

The present study was conducted to examine the generation of reactive oxygen species (ROS) during micromanipulation procedures in bovine somatic cell nuclear transfer (SCNT) embryos. Bovine enucleated oocytes were electrofused with donor cells, activated by a combination of Ca-ionophore and 6-dimethylaminopurine culture. Oocytes and embryos were stained in dichlorodihydrofluorescein diacetate or 3'-(p-hydroxyphenyl) fluorescein dye and the $H_2O_2$ or $^.OH$ radical levels were measured. $In$ $vitro$ fertilization (IVF) was performed for controls. The samples were examined with a fluorescent microscope, and fluorescence intensity was analyzed in each oocyte and embryo. The $H_2O_2$ and $^.OH$ radical levels of reconstituted oocytes were increased during manipulation (37.2~49.7 and 51.0~55.2 pixels, respectively) as compared to those of mature oocytes ($p$<0.05). During early $In$ $vitro$ culture, the ROS levels of SCNT embryos were significantly higher than those of IVF embryos ($p$<0.05). These results suggest that the cellular stress during micromanipulation procedures can generate the ROS in bovine SCNT embryos.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.239-244
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• 2009

In the current study, inhibitory activity of 8 selected Korean edible plants of Lamiaceae family against $\alpha$-glucosidases, prepared from rat small intestine acetone powder was evaluated. Total flavonoids and oxygen radical absorbance capacity (ORAC) were also investigated. Methyl alcohol extracts of Scutellaria indica (SI) had the highest $\alpha$-glucosidase inhibitory activity relevant for potentially managing hyperglycemia, followed by Clinopodium gracile (CG) and Thymus quinquecostatus (TQ). These 3 species also showed significant antioxidant activity in ORAC system. The $\alpha$-glucosidase inhibitory activity of the extracts was compared to selected phenolics. Among the standard phenolics tested quercetin which was major flavonoid in the extracts had the highest $\alpha$-glucosidase inhibitory activity. CG, TQ, and SI which had high quercetin content and ORAC values also exhibited significant sucrase inhibitory activity. Results suggested that selected 3 Korean Lamiaceae species have the potential development of effective dietary strategy for postprandial hyperglycemia and oxidative stress-linked diabetes complications.