• Environmental Analysis Health and Toxicology
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• v.24 no.1
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• pp.33-41
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• 2009

Among the toxicants in the environment dioxin-like compounds, including TCDD(2,3,7,8-Tetrachlorodibenzo-p-Dioxin), are well known as carcinogen and teratogen. TCDD the most toxic of these compounds, may result in a wide variety of adverse health effects in humans and environment, including carconogenesis, hepatotoxicity, teratogenesis, and immunotoxicity. Also TCDD increases superoxide, peroxide radicals and induces oxidative stress that leads to breakage of DNA single-strand and mitochondrial dysfunction. Recently, there have been reports that persistent organic pollutants(POPs) may be causing metabolic disease through mitochondrial toxicity. In order to examine if dioxin brings about toxicity on mitochondria directly, we measured the change of the mitochondrial membrane potential after exposure to TCDD using JC-1 dye. After short time exposure of dioxin, mitochondrial depolarization was observed but it recovered to the control level immediately. This TCDD effect on mitochondrial membrane potential was not correlated either to the production of reactive oxygen species(ROS) or extracellular $Ca^{2+}$ by TCDD. Less than 2 hours exposure of TCDD did not show any change in ROS production but 0.25 nM TCDD for 48 hours or 0.5 nM TCDD for 12 hours exposure did increase in ROS production. Under these conditions of ROS production by TCDD, no changes in the mitochondrial membrane potential by TCDD was observed.

• Korean Journal of Plant Resources
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• v.25 no.5
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• pp.568-577
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• 2012

The objective of this study was to investigate the antioxidative capacity of ethanol extracts from Rumex crispus L. The concentration of R. crispus L. extract at which DPPH radical scavenging activity was inhibited by 50% was 2.15 mg/mL, which was lower than that of ${\alpha}$-tocopherol (0.43 mg/mL), as compared to 100% by pyrogallol as a reference. Total antioxidant status was examined by total antioxidant capacity against ABTS radical reactions. Total antioxidant capacities of R. crispus L. extract at concentrations of 0.1 and 1 mg/mL were 0.47 and 2.33 mM Trolox equivalents, respectively, which were higher than those of ${\alpha}$-tocopherol. Superoxide scavenging activities of R. crispus L. extract at concentrations of 0.1 and 1 mg/mL were 21.5 and 78.9%, respectively, which were not significantly (p>0.05) different from those of catechin. Oxygen radical absorbance capacities of R. crispus L. extract at concentrations of 20 and 100 ${\mu}g/mL$ were 62.5 and 156.4 ${\mu}M$ Trolox equivalents, respectively, which were lower than those of ascorbic acid. Cupric reducing antioxidant capacities of R. crispus L. extract at concentrations of 0.1 and 1 mg/mL were 0.28 and 1.88 mM Trolox equivalents, which were similar or significantly (p<0.05) higher than those of ${\alpha}$-tocopherol, respectively. R. crispus L. extract prevented supercoiled DNA strand breakage induced by hydroxyl radical and peroxyl radical. Total phenolic contents of R. crispus L. extract at concentrations of 0.5 and 5 mg/mL were 0.58 and 3.85 mM gallic acid equivalents, respectively. R. crispus L. extract at concentration of 0.1 and 0.5 mg/mL inhibited 0.2 mM tert-butyl hydroperoxide-induced cytotoxicity by 38.5 and 63.5%, respectively, in HepG2 cell culture system. Thus, strong antioxidant and cytotoxicity-inhibiting effects of R. crispus L. extract seem to be due to, at least in part, the prevention from free radicals-induced oxidation as well as high levels in total phenolic contents.

• Environmental Analysis Health and Toxicology
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• v.20 no.4 s.51
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• pp.365-374
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• 2005

Ambient air particulate matters are classified into two distinct modes in sire distribution, namely the coarse and fine particles. Correlation between high particulate concentration and adverse effect on human populations has long been recognized. However, the toxicology of these adverse efforts has not been clarified. We investigated the genotoxic effect of PM 2.5 collected from urban area in Seoul by comet assay (A549 cells), CBMN assay (CHO-K1 cells) and EROD-microbioassay (H4IIE cells). Results from in vitro micronucleus assay and comet assay showed that PM 2.5 samples collected from traffic area, residential area and indoor air induced chromosomal damage and DNA breakage in a non-cytotoxic dose. The complex mixture effect of these PM 2.5 extracts was quantified by EROD-microbioassay in terms of its bio-TEQ (biologiral -TCDD equivalent concentration) which was 70.87$\pm$28.07, 93.55$\pm$21.80 and 14.31 $\pm$ 1.10 ng/g-PM 2.5 in traffic area, residental area and indoor air samples, respectively. Conclusively, we suggested that PM 2.5 collected from traffic area and residential area contains CYPIA inducer and genotoxic materials.

• Environmental Analysis Health and Toxicology
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• v.28
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• pp.3.1-3.8
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• 2013

Objectives We investigated the genotoxic effects of 40-59 nm silver nanoparticles (Ag-NPs) by bacterial reverse mutation assay (Ames test), in vitro comet assay and micronucleus (MN) assay. In particular, we directly compared the effect of cytochalasin B (cytoB) and rat liver homogenate (S9 mix) in the formation of MN by Ag-NPs. Methods Before testing, we confirmed that Ag-NPs were completely dispersed in the experimental medium by sonication (three times in 1 minute) and filtration ($0.2{\mu}m$ pore size filter), and then we measured their size in a zeta potential analyzer. After that the genotoxicity were measured and especially, S9 mix and with and without cytoB were compared one another in MN assay. Results Ames test using Salmonella typhimurium TA98, TA100, TA1535 and TA1537 strains revealed that Ag-NPs with or without S9 mix did not display a mutagenic effect. The genotoxicity of Ag-NPs was also evaluated in a mammalian cell system using Chinese hamster ovary cells. The results revealed that Ag-NPs stimulated DNA breakage and MN formation with or without S9 mix in a dose-dependent manner (from $0.01{\mu}g/mL$ to $10{\mu}g/mL$). In particular, MN induction was affected by cytoB. Conclusions All of our findings, with the exception of the Ames test results, indicate that Ag-NPs show genotoxic effects in mammalian cell system. In addition, present study suggests the potential error due to use of cytoB in genotoxic test of nanoparticles.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1315-1329
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• 2015

The objective of this study was to investigate anticytotoxic and antioxidatative capacities of ethanol extracts from Acer tegmentosum Maxim (A. tegmentosum) stem in vitro. The extract at concentration of 200 ug/mL inhibited 10 and 20 ug/mL arsenic trioxide-induced cytotoxicity of HepG2 cells by 79.3 and 57.5%, respectively. The extract at concentration of 200 ug/mL inhibited 0.2 and 0.5 mM t-BHP-induced cytotoxicity of HepG2 cells by 66.3 and 35.7%, respectively. Antioxidative effects of the extract were examined via measurement of ABTS, superoxide, and peroxyl radical scavenging activities. ABTS radical scavenging activity of the extract was higher than that of ${\alpha}$-tocopherol. Superoxide scavenging activity of the extract was higher than that of catechin. Oxygen radical absorbance capacity of the extract was higher than that of ascorbic acid. Cupric reducing antioxidant capacity of the extract was higher than that of ${\alpha}$-tocopherol. The extract at concentrations of 100 and $500{\mu}g/mL$ inhibited 10 mM t-BHP-induced lipid peroxidation of HepG2 cells by 38.2 and 80.7%, respectively. The extract prevented supercoiled DNA strand breakage induced by hydroxyl or peroxyl radical. Total phenolic and flavonoid contents of the extract at concentration of $100{\mu}g/mL$ were 71.3 nmol/mL gallic acid and 18.8 nmol/mL catechin equivalents, respectively. Thus, strong cytoprotective and antioxidant effects of A. tegmentosum stem extract seem to be due to, at least in part, the prevention from free radicals-induced oxidation as well as high levels in polyphenolic contents.

• Biomolecules & Therapeutics
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• v.25 no.4
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• pp.404-410
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• 2017

Benzylideneacetophenone derivative (1E)-1-(4-hydroxy-3-methoxyphenyl) hept-1-en-3-one (JC3) elicited cytotoxic effects on MDA-MB 231 human breast cancer cells-radiation resistant cells (MDA-MB 231-RR), in a dose-dependent manner, with an $IC_{50}$ value of $6{\mu}M$ JC3. JC3-mediated apoptosis was confirmed by increase in sub-G1 cell population. JC3 disrupted the mitochondrial membrane potential, and reduced expression of anti-apoptotic B cell lymphoma-2 protein, whereas it increased expression of pro-apoptotic Bcl-2-associated X protein, leading to the cleavage of caspase-9, caspase-3 and poly (ADP-ribose) polymerase. In addition, JC3 activated mitogen-activated protein kinases, and specific inhibitors of these kinases abrogated the JC3-induced increase in apoptotic bodies. JC3 increased the level of intracellular reactive oxygen species and enhanced oxidative macromolecular damage via lipid peroxidation, protein carbonylation, and DNA strand breakage. Considering these findings, JC3 is an effective therapy against radiation-resistant human breast cancer cells.

• Proceedings of the Plant Resources Society of Korea Conference
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• v.18 no.1
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• pp.52-60
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• 2005

The objectives of present study were to investigate the hepatoprotective and antioxidative effects of onion extracts. Primary cultures of rat hepatocytes were incubated with 1.5 mM tert-butyl hydroperoxide(t-BHP), potent oxidizing agent for liver injury for 1 hr in the presence or absence of various concentrations (0, 0.01, 0.05, 0.1 or 0.3 mg/ml) of onion extract. Cytotoxicity and cell viability were determined by measuring glutamic oxaloacetic transaminase(GOT) activity, lactate dehydrogenase(LDH) activity and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT) value. Lipid peroxidation was evaluated using thiobarbituric acid reactive substances(TBARS) assay. Effects on antioxidant system were determined by measuring catalase, glutathione peroxidase(GSH-Px), glutathione reductase(GSH-Rd) activities as well as DNA strand breaking assay. Incubation with t-BHP alone increased GOT and LDH activities and TBARS concentration but decreased MTT reduction. Onion extracts at the concentration of 0.05 mg/ml began to decrease GOT and LDH activities induced by 1.5 mM t-BHP. Decreased MTT reduction began to be increased by onion extract at the concentration of 0.01 mg/ml. Onion extracts at the concentration of 0.01 mg/ml began to decrease TBARS concentration induced by t-BHP. Taken together, onion extracts prevented t-BHP-induced hepatocyte injury and lipid peroxidation. Catalase, GSH-Px and GSH-Rd activities of hepatocytes were significantly decreased by 1.5 mM t-BHP for 1 hr incubation. Onion extracts, on the other hand, at the concentration of 0.1 mg/ml began to prevent t-BHP-induced decrease in catalase, GSH-Px and GSH-Rd activities. Onion extracts prevented hydroxyl radical-induced single-strand breakage in dose-dependent manner when plasmid DNA was incubated with various concentrations of onion extracts in the presence of Fenton regents producing hydroxyl radical. These results demonstrate that onion extracts suppressed t-BHP-induced cytoctoxicity, decreased viability and lipid peroxidation and increased GSH-Px, GSH-Rd and catalase activities. Thus hepatoprotective and antioxidant effects of onion extract seem to be due to, at least in part, the increase in antioxidant enzyme activities as well as prevention from hydroxyl radical-induced oxidation, followed by inhibition in lipid peroxidation.

• Applied Biological Chemistry
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• v.27 no.4
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• pp.264-270
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• 1984

In order to obtain mutagenic data of enzymatic browning reaction products, we investigated their mutagenicity. The rec-assay with Bacillus subtilis strains $H17(rec^+)$ and $M45(rec^-)$ were carried out with their spores. Detection of double strand breakage in calf-thymus DNA was investigated into sample solution with and without $Cu^{2+}$ by the agarose slab gel electrophoresis. In the rec-assay, catechol, pyrocatechol, DL-dopa, 3,4-dihydroxytoluene, hydroquinone, hydroxyhydroquinone with and without $Cu^{2+}$ in 0.05M ana 0.1M at the enzymatic browning reaction products stowed mutagenic action. And also browning solution of 0.05M hydroxyhydroquinone and catechol with $Cu^{2+}$, hydroquinone with and without $Cu^{2+}$ of 0.1M at the enzymatic browning reaction products were strong mutagenic action. The DNA breakability of the enzymatic browning reaction products of 0.1M pyrogallol was stronger than that of 0.05M pyrogallol browning solution with $Cu^{2+}$ and 3,4-dihydroxytoluene browning solution was stronger than that of 0.01M 3,4-dihydroxytoluene browning solution.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.719-730
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• 2014

The hot water extract from Artemisia capillaris fermented with Hericium erinaceum mycelium (AC-HE) were assessed for the protection against oxidative modification of biological macromolecules and cell death. Antioxidant activity of AC-HE evaluated using 2,2-diphenyl-1-picrylhydrazyl radical, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical and peroxyl radical scavenging assays. AC-HE showed 61.73% DPPH radical scavenging activity at $500{\mu}g/mL$, 97.39% ABTS radical scavenging activity at $250{\mu}g/mL$, and 44.18% peroxyl radical scavenging activity at $100{\mu}g/mL$. AC-HE were shown to significantly inhibited DNA strand breakage induced by peroxyl radical. AC-HE also prevented peroxyl radical-mediated human serum albumin modification. AC-HE effectively inhibited $H_2O_2$ induced cell death and significantly increased of the 11.47% cell survival at $100{\mu}g/mL$. AC-HE also decreased intracellular reactive oxygen species (ROS) levels in $H_2O_2$-treated cells. The results suggested that AC-HE can contribute to antioxidant and protected cells from oxidative stress-induced cell injury.

• Korean Journal of Plant Resources
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• v.18 no.3
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• pp.470-478
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• 2005

The objective of present study was to investigate the hepatoprotective and antioxidative effects of onion extracts. Primary cultures of rat hepatocytes were incubated with 1.5 mM tort-butyl hydroperoxide(t-BHP), potent oxidizing agent to liver, for 1 hr in the presence or absence of various concentrations (0, 0.01, 0.05, 0.1 or 0.3 mg/ml) of onion extract. Incubation with t-BHP increased glutamic oxaloacetic transaminase(GOT) and lactate dehydrogenase(LDH) acitivities and thiobarbituric acid reactive substances(TBARS) concentration but decreased 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT) reduction. Onion extracts at the concentration of 0.05 mg/ml decreased t-BHP-induced GOT and LDH activities. Onion extract at the concentration of 0.1 mg/ml increased t-BHP-induced MTT reduction. Onion extract at the concentration of 0.01 mg/ml decreased t-BHP-induced TBARS concentration. Taken together, onion extracts prevented t-BHP-induced hepatocyte injury and lipid peroxidation. Catalase, glutathione peroxidase(GSH-Px) and glutathione reductase(GSH-Rd) activities of hepatocytes were significantly decreased by t-BHP. Onion extracts at the concentration of 0.1 mg/ml prevented t-BHP-induced decrease in catalase, GSH-Px and GSH-Rd activities. Onion extracts prevented hydroxyl radical-induced single-strand breakage in dose-dependent manner when plasmid DNA was incubated with various concentrations of onion extracts in the presence of Fenton reagents producing hydroxyl radical. These results demonstrate that onion extracts suppressed t-BHP-induced cytoctoxicity, decreased viability and lipid peroxidation and increased GSH-Px, GSH-Rd and catalase activities. Thus hepatoprotective and antioxidant effects of onion extract seem to be due to, at least in part, the increase in antioxidant enzyme activities as well as prevention from hydroxyl radical-induced oxidation, followed by inhibition of lipid peroxidation.