• Molecules and Cells
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• v.21 no.1
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• pp.161-165
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• 2006

Dichlorodihydrofluorescein ($DCFH_2$) is a widely used probe for intracellular $H_2O_2$. However, $H_2O_2$ can oxidize $DCFH_2$ only in the presence of a catalyst, whose identity in cells has not been clearly defined. We compared the peroxidase activity of Cu,Zn-superoxide dismutase (CuZnSOD), cytochrome c, horseradish peroxidase (HRP), $Cu^{2+}$, and $Fe^{3+}$ under various conditions to identify an intracellular catalyst. Enormous increase by bicarbonate in the rate of $DCFH_2$ oxidation distinguished CuZnSOD from cytochrome c and HRP. Cyanide inhibited the reaction catalyzed by CuZnSOD but accelerated that by $Cu^{2+}$ and $Fe^{3+}$. Oxidation of $DCFH_2$ by $H_2O_2$ in the presence of a cell lysate was also enhanced by bicarbonate and inhibited by cyanide. Confocal microscopy of $H_2O_2$-treated cells showed enhanced DCF fluorescence in the presence of bicarbonate and attenuated fluorescence for the cells pre-incubated with KCN. Moreover, DCF fluorescence was intensified in CuZnSOD-transfected HaCaT and RAW 264.7 cells. We propose that CuZnSOD is a potential intracellular catalyst for the $H_2O_2$-dependent oxidation of $DCFH_2$.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.4
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• pp.872-882
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• 2009

Sachil-Tang (SCT) has been traditionally used as a prescription of spasm of the esophagus by stress, pectoralgia and oppressive feeling of the chest in Oriental medicine. This study was carried out to investigate the antioxidant activities of the ethanol extract of SCT and its inhibitory effect on intracellular oxidation and vascular cell adhesion molecule-1 expression in human umbilical vein endothelial cells (HUVECs) using various methods. The SCT extract showed a strong inhibitory effect on free radical generating model systems, including DPPH radical, superoxide anions, hydroxyl radical, peroxynirite and nitric oxide. Besides, the SCT extract exhibited a strong inhibitory effect on lipid peroxidation in rat liver homogenate induced by $FeCl_2$-ascorbic acid, and protected plasmid DNA against the strand breakage in a Fenton's reaction system. The SCT extract also inhibited copper-mediated oxidation of human low-density lipoprotein (LDL), and repressed relative electrophoretic mobility of LDL. Furthermore, the SCT extract protected intracellular oxidation induced by various free radical generators and inhibited expression of vascular cell adhesion molecule-1 (VCAM-1) in HUVECs. These results suggest that SCT can be an effective natural antioxidant and a possible medicine of atherosclerosis.

• Molecules and Cells
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• v.39 no.1
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• pp.46-52
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• 2016

It is increasingly apparent that nature evolved peroxiredoxins not only as $H_2O_2$ scavengers but also as highly sensitive $H_2O_2$ sensors and signal transducers. Here we ask whether the $H_2O_2$ sensing role of Prx can be exploited to develop probes that allow to monitor intracellular $H_2O_2$ levels with unprecedented sensitivity. Indeed, simple gel shift assays visualizing the oxidation of endogenous 2-Cys peroxiredoxins have already been used to detect subtle changes in intracellular $H_2O_2$ concentration. The challenge however is to create a genetically encoded probe that offers real-time measurements of $H_2O_2$ levels in intact cells via the Prx oxidation state. We discuss potential design strategies for Prx-based probes based on either the redoxsensitive fluorophore roGFP or the conformation-sensitive fluorophore cpYFP. Furthermore, we outline the structural and chemical complexities which need to be addressed when using Prx as a sensing moiety for $H_2O_2$ probes. We suggest experimental strategies to investigate the influence of these complexities on probe behavior. In doing so, we hope to stimulate the development of Prx-based probes which may spearhead the further study of cellular $H_2O_2$ homeostasis and Prx signaling.

• Biotechnology and Bioprocess Engineering:BBE
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• v.3 no.2
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• pp.109-111
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• 1998

The effect of dissolved oxygen concentration on the metabolism of glucose in Pseudomonas putida BM014 was investigated. Glucose was completely converted to 2-ketogluconate via extracellular oxidative pathway and then taken up for cell growth under the condition of sufficient dissolved oxygen concentration. On the other hand, oxygen limitation below dissolved oxygen tension (DOT) value of 20% of air saturation caused the shift of glucose metabolism from the extracellular oxidative pathway to the intracellular phosphorylative pathway. Specific activities of hexokinase and gluconate kinase in intracellular phosphorylation pathway decreased as the DOT increased, while 2-ketogluconokinase activity in extracellular oxidative pathway increased under the same condition. This result can be usefully applied to microbial transformation of glucose to 2-ketogluconate, the synthetic precursor for iso-vitamine C, with almost 100% yield via extracellular oxidation by simple DOT control.

• Journal of Korean Medicine Rehabilitation
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• v.26 no.3
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• pp.51-58
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• 2016

Objectives This study was designed to investigate whether the Cheongajihwang-Tang (CT) has an inhibitory effect association with oxidation or inflammation in RAW264.7 cells. Methods Cytotoxic activity of CT extract on RAW264.7 cells was evaluated by using 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) solution. Nitric oxide production was measured using Griess reagent system. The total phenolic contents and 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was measured to evaluate the anti-oxidative effects of CT. Dichlorofluorescin diacetate (DCFH-DA) has been used as a substrate for measuring intracellular oxidant production. Results Cheongajihwang-Tang does not impair the cell viability in tested concentration. CT showed anti-oxidative effects in vitro by decreasing electron donating ability, and also showed anti-inflammatory effects suppressing NO and ROS expression in LPS induced RAW264.7 activation. CT inhibited the generation of intracellular ROS production as dose dependant manner. Conclusions CT has anti-oxidative effects and anti-inflammatory activities. These results indicate that CT extract has an anti-inflammatory activities via anti-oxidative effects.

• The Journal of Internal Korean Medicine
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• v.33 no.4
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• pp.438-447
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• 2012

Objectives : In this study, we investigated the effect and the underlying mechanism of ethanol extract of Benincasa seeds on a cellular model of non-alcoholic fatty liver disease (NAFLD) established by treating HepG2 cells with palmitate. Methods : We evaluated ethanol extract of Benincasa seeds (EEBS) for its hepatic lipid-lowering potential in fatty acid overloaded HepG2 cells. After incubation in palmitate containing media with or without EEBS, intracellular neutral lipid accumulations were quantified by Nile red staining. We also investigated the effect of EEBS on lipogenesis and ${\beta}$-oxidation. $LXR{\alpha}$-dependent SREBP-1c activation, expression of lipogenic genes, and expression of ${\beta}$-oxidation related genes were determined with or without pretreatment of EEBS. Results : EEBS significantly attenuated palmitate-induced intracellular neutral lipid accumulation in HepG2 cells. EEBS suppressed fatty acid synthesis by inhibiting $LXR{\alpha}$-dependent SREBP-1c activation. EEBS also repressed SREBP-1c mediated induction of lipogenic genes, including ACC, FAS, and SCD-1. However, EEBS had no effect on ${\beta}$-oxidation related CPT-1 and $PPAR{\alpha}$ gene expression. Conclusions : Our results suggest that EEBS has an efficacy to decrease hepatic lipid accumulation, and this effect was mediated by inhibiting the $LXR{\alpha}$-SREBP-1c pathway that leads to expression of lipogenic genes and hepatic steatosis. Therefore, the Benincasa seeds may have a potential clinical application for treatment of this chronic liver disease.

• Proceedings of the Korean Society of Food Science and Nutrition Conference
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• 2004.11a
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• pp.265-270
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• 2004

Coronary heart disease (CHD) has been the number one killer in western society for a long time, and CHD in most instances is due to atherosclerosis. One of the earliest events in atherogenesis is the intracellular accumulation of lipids, particularly cholesterol esters, in the aortic intima. The lipids presumably came from the uptake of plasma lipoproteins, particularly from LDL. These foam cells were identified as being predominantly as macrophages. Currently, it is believed that oxidation of low density lipoprotein (LDL) might contribute to the generation of foam cells. An outcome of the oxidation hypothesis is that the consumption of antioxidants would be beneficial. In this study, Boldine, an alkaloid of Peumus boldus was tested for their antioxidant potency both in, in vitro oxidation system and in mouse models. Boldine decreased the ex-vivo oxidation of Low-density lipoprotein (LDL). In vivo studies were performed to study the effect of these compounds on the atherosclerotic lesion formation in LDL r-/- mice. Three groups of LDL r-/- mice (N=12 each) were fed an atherogenic diet. Group 1 was given vehicle and group 2 and 3 were given 1 and 5 mg of Boldine/day in addition to the atherogenic diet. The results indicated that there was a decrease in lesion formation reaching a 40% reduction due to Boldine compared to controls. The in vivo tolerance of Boldine in humans (has been used as an herbal medicine in other diseases) should make it an attractive alternative to vitamin E.

• The Korea Journal of Herbology
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• v.25 no.2
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• pp.99-106
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• 2010

Objectives : This study was designed to investigate the effects of anti-oxidation of fractionated Pulsatilla koreana $N_{AKAI}$ (PK) extracts. And we examined to determine that a certain fractionated extract has the best anti-oxidative effects between the fractionated PK extracts. Methods : Anti-oxidative effects of fractionated PK extracts was measured by scavenging activities of DPPH, superoxide, nitric oxide (NO) and peroxynitrite radicals. And also scavenging activities of anti-oxidation in lipopolysaccharide (LPS)-treated RAW 264.7 cell was measured. After these examination, we determined a fraction that has best anti-oxidative effects. Results : Fractionated PK extracts inhibited radicals effectively. Also in RAW 264.7 cell, intracellular oxidation has inhibited by PK extracts. In these tests, ethyl acetate (EA) fraction has the best anti-oxidative effects among PK extracts. Conclusions : This results demonstrate that PK extracts exhibit anti-oxidative effects. And EA fraction has the best inhibition effects among the six fractions of PK.

• Journal of Korean Society of Water and Wastewater
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• v.36 no.5
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• pp.249-260
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• 2022

The effect of permanganate oxidation was investigated as water treatment strategy with a focus on comparing the reaction characteristics of NaOCl and sodium permanganate (NaMnO₄) in algae (Monoraphidium sp., Micractinium inermum, Microcystis aeruginosa)-contained water. Flow cytometry explained that chlorine exposure easily damaged algae cells. Damaged algae cells release intracellular organic matter, which increases the concentration of organic matter in the water, which is higher than by NaMnO₄. The oxidation reaction resulted in the release of toxin (microcystin-LR, MC-LR) in water, and the reaction of algal organic matter with NaOCl resulted in trihalomethanes (THMs) concentration increase. The oxidation results by NaMnO₄ significantly improved the concentration reduction of THMs and MC-LR. Therefore, this study suggests that NaMnO₄ is effective as a pre-oxidant for reducing algae damage and byproducts in water treatment process.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.93-100
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• 2014

Background: Curcumin has has been reported to exert anti-inflammatory, anti-oxidation and anti-angiogenic activity in various types of cancer. It has also been shown to induce apoptosis in leukemia cells. We aimed to unravel the role of the redox pathway in Curcumin mediated apoptosis with a panel of human leukemic cells. Materials and Methods: In this study in vitro cytotoxicity of Curcumin was measured by MTT assay and apoptotic effects were assessed by annexin V/PI, DAPI staining, cell cycle analysis, measurement of caspase activity and PARP cleavage. Effects of Curcumin on intracellular redox balance were assessed using fluorescent probes like $H_2DCFDA$, JC1 and an ApoGSH Glutathione Detection Kit respectively. Results: Curcumin showed differential anti-proliferative and apoptotic effects on different human leukemic cell lines in contrast to minimal effects on normal cells. Curcumin induced apoptosis was associated with the generation of intracellular ROS, loss of mitochondrial membrane potential, intracellular GSH depletion, caspase activation. Conclusions: As Curcumin induces programmed cell death specifically in leukemic cells it holds a great promise as a future therapeutic agent in the treatment of leukemia.