• Journal of Plant Biotechnology
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• v.36 no.3
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• pp.244-254
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• 2009

The hypersensitive reaction (HR) is the most common plant defense reaction against pathogens. HR is produced during both host- and nonhost-incompatible interactions. Several reports suggest that similarities exist between host and nonhost resistances. We assayed the pattern of generation of reactive oxygen species (ROS) and scavenging enzyme activities during nonhost pathogen-plant interactions (Xanthomonas campestris pv. campestris/Capsicum annuum L.) and incompatible host pathogen-plant interactions (Xanthomonas campestris pv. vesicatoria race1/Capsicum annuum L.). Both ${O_2}^-\;and\;H_2O_2 $ accumulated much faster during nonhost resistance when compared to the host resistance. The scavenging enzyme activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) were also different during the host- and nonhost-incompatible interactions. CAT activity was much higher during nonhost resistance, and several new isozymes of SOD and POX were detected during nonhost resistance when compared to the host resistance. Lipoxygenase (LOX) activity was higher in host resistance than nonhost resistance during the early stages of infection. Interestingly, the nitric oxide (NO) radical accumulated equal amounts during both host and nonhost resistance at early stages of infection. Further studies are needed to determine the specific pathways underlying these differences between host and nonhost resistance responses.

• Journal of Veterinary Clinics
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• v.34 no.4
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• pp.261-267
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• 2017

The aim of this study was to investigate the antibacterial properties of chitosan silver nanocomposites (CAgNCs) using pathogenic Vibrio ichthyoenteri as a bacterial model. Results of agar disc diffusion and turbidimetric assays showed that CAgNCs could inhibit the growth of V. ichthyoenteri in concentration dependent manner. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of CAgNCs were 75 and $125{\mu}g/mL$, respectively. Furthermore, CAgNCs treatment induced the reactive oxygen species (ROS) level in V. ichthyoenteri cells in concentration and time dependent manner, suggesting that it generates oxidative stress, leading to bacterial cell death. The field emission scanning electron microscope (FE-SEM) images of CAgNCs treated V. ichthyoenteri exhibited strong cell membrane damage than un-treated control bacteria. MTT assay results showed the highest cell viability (22%) at $75{\mu}g/mL$ of CAgNCs treated bacteria samples. The results from this study suggest that CAgNCs is a potential antibacterial agent to control fish pathogenic bacteria.

• The Korean Journal of Food And Nutrition
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• v.31 no.4
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• pp.457-463
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• 2018

In this study, we analyzed the protective effects of the vitamin C in the streptozotocin (STZ)-induced apoptosis using the SH-SY5Y, a neuroblastoma cell line. The cells were pretreated with the vitamin C ($100{\mu}g$) for 30 min, followed by the 24-hr treatment with the 2.5-mM STZ. The cell-viability assay using the Cell Counting Kit (CCK)-8 revealed the cell-survival rate increased by 15% following the vitamin-C pretreatment compared to the STZ-only treatment. Moreover, we conducted the western-blot analysis to determine the protective effect of the vitamin C regarding the apoptosis. Compared to those in the STZ-only-treatment group, the p-ERK and Bcl-2 expressions increased in the vitamin-C-pretreatment group, whereas the p-JNK and Bax expressions decreased. The vitamin-C pretreatment increased the expression of the SOD-1, an antioxidant enzyme, by more than 30%, indicating its protective role in the STZ-induced oxidative stress. Also, we found both the intrinsic- and extrinsic-pathway mechanisms of the STZ-induced apoptosis. The results of this study $s{\mu}ggest$ vitamin C may help prevent the neurodegenerative diseases.

• Preventive Nutrition and Food Science
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• v.19 no.3
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• pp.178-186
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• 2014

Many recent studies have focused on maintaining a healthy life by preventing and/or postponing the aging process. Numerous studies have reported that continuous exposure to reactive oxygen species can stimulate skin aging and that excessive accumulation of fat can cause an impaired skin barrier and tissue structure alterations. Thus, the maintenance of antioxidant homeostasis and the suppression of adipose accumulation are important strategies for skin anti-aging. Here, we prepared three types of extracts [whole juice, acetone-perchloric acid (PCA), and ethanol] from 20 fruits and medicinal herbs native to the Gyeongnam area of Korea. The total phenolic content of each extract was analyzed, and we observed higher total phenolic contents in the medicinal herbs. Consistent with this, the results of the oxygen radical absorbance activity capacity assay indicated that the in vitro antioxidant activities of the medicinal herb extracts were stronger than those of the fruit extracts. The fruits and medicinal herbs had strong effects on cell-based systems, including $H_2O_2$-induced oxidative stress in human keratinocytes and 3T3-L1 lipid accumulation. Nishimura Wase persimmon, Taishu persimmon, wrinkled giant hyssop, sweet wormwood, Chinese cedar, red perilla, tan shen, hiyodori-jogo, and cramp bark may be natural anti-aging materials with effective antioxidant and anti-adipogenic activities. Taken together, our findings may provide scientific evidence supporting the development of functional foods and nutraceuticals from fruits and medicinal herbs.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.6
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• pp.818-823
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• 2012

Tall fescue (Festuca arundinacea Schreb.) is an important cool season forage plant that is not well suited to extreme heat, salts, or heavy metals. To develop transgenic tall fescue plants with enhanced tolerance to abiotic stress, we introduced an alfalfa Hsp23 gene expression vector construct through Agrobacterium-mediated transformation. Integration and expression of the transgene were confirmed by polymerase chain reaction, northern blot, and western blot analyses. Under normal growth conditions, there was no significant difference in the growth of the transgenic plants and the non-transgenic controls. However, when exposed to various stresses such as salt or arsenic, transgenic plants showed a significantly lower accumulation of hydrogen peroxide and thiobarbituric acid reactive substances than control plants. The reduced accumulation of thiobarbituric acid reactive substances indicates that the transgenic plants possessed a more efficient reactive oxygen species-scavenging system. We speculate that the high levels of MsHsp23 proteins in the transgenic plants protect leaves from oxidative damage through chaperon and antioxidant activities. These results suggest that MsHsp23 confers abiotic stress tolerance in transgenic tall fescue and may be useful in developing stress tolerance in other crops.

• Journal of the Korean Applied Science and Technology
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• v.26 no.3
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• pp.269-278
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• 2009

In this study, the anti oxidative effects, inhibitory effects on elastase, and components of Securinega suffruticosa extracts were investigated. The free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities ($FSC_{50}$) and reactive oxygen species ROS) scavenging activities ($OSC_{50}$) of extract/fractions from Securinega suffruticosa were measured. The aglycone fraction ($9.04\;{\pm}\;0.51\;{\mu}g/mL$) and 50 % ethanol extract ($1.05\;{\pm}\;0.41\;{\mu}g/mL$) showed the most effective scavenging activities. The protective effects on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The aglycone fraction exhibited the most prominent cellular protective effect (${\tau}_{50},\;102.77\;{\pm}\;5.37$ min at $10{\mu}g/mL$). The inhibitory effect of ethyl acetate fraction on tyrosinase were of examined ($210.0\;{\pm}\;1.02\;{\mu}g/mL$). The inhibitory effect of aglycone fraction on elastase were also investigated ($17.6\;{\pm}\;1.26\;{\mu}g/mL$). These results indicate that extract/fractions of Securinega suffruticosa can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS. Securinega suffruticosa extract could be used as a new cosmeceutical ingredient for whitening and anti-wrinkle products.

• BMB Reports
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• v.43 no.1
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• pp.46-51
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• 2010

Thermal burn injury induces inflammatory cell infiltrates in the dermis and thickening of the epidermis. Following a burn injury, various mediators, including reactive oxygen species (ROS), are produced in macrophages and neutrophils, exposing all tissues to oxidative injury. The anti-oxidant activities of flavonoids have been widely exploited to scavenge ROS. In this study, we observed that several flavonoids-kaempferol, quercetin, fisetin, and chrysin-inhibit LPS-induced IL-8 promoter activation in RAW 264.7 cells. In contrast with quercetin and fisetin, pretreatment of kaempferol and chrysin did not decrease cell viability. Inflammatory cell infiltrates in the dermis and thickening of the epidermis induced by burn injuries in mice was relieved by kaempferol treatment. However, the injury was worsened by fisetin, quercetin, and chrysin. Expression of TNF-a induced by burn injuries was decreased by kaempferol. These findings suggest the potential use of kaempferol as a therapeutic in thermal burn-induced skin injuries.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2002.10a
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• pp.169-169
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• 2002

The mobilizable amount of transition metals is a fraction of the total amount of the metal from urban particulate matter. Although the fraction is small, some metals (Fe, Cu) are the major participants in a reaction that generates reactive oxygen species (ROS), which can damage various biomolecules. Damaging effects of the metals can be measured by the single strand breakage (SSB) of X174 RFI DNA or the carbonyl formation of protein. In another study, we have shown that more metals are mobilized by PM2.5 than by PM10 in general. DNA SSB of >20% for PM2.5 and >15% for PM10 was observed in the presence of chelator (EDTA or citrate)/reductant (ascorbate), compared to the control (<3%) only with the chelator. The carbonyl formation by both PMs was very similar in the presence of the chelator, regardless of the kind of proteins. Compared to the control in the absence of chelator/reductant, 3.3 times and 4.9 times more carbonyl formation for PM2.5 and PM10, respectively, was obtained with BSA in the presence of chelator/reductant, showing that PM10 induced 33% more damage than PM2.5. However, 4.8 times and 1.9 times more carbonyl formation for PM2.5 and PM10, respectively, was observed with lysozyme in the presence of chelator/reductant, showing that PM2.5 induced 250% more damage than PM10. Although different proteins showed different sensitivities toward ROS, all these results indicate that the degrees of the oxidation of or damage to the biomolecules by the mobilized metals were higher with PM2.5 than with PM10. Therefore, it is expected that more metals mobilized from PM2.5 than from PM10, more damage to the biomolecules by PM2.5 than by PM10. We suggest that when the toxicity of the dust particle is considered, the particle size as well as the mobilizable fraction of the metal should be considered in place of the total amounts.

• Fisheries and Aquatic Sciences
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• v.20 no.7
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• pp.9.1-9.13
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• 2017

Background: Metal-responsive transcription factor-1 (MTF-1) is a key transcriptional regulator playing crucial roles in metal homeostasis and cellular adaptation to diverse oxidative stresses. In order to understand cellular pathways associated with metal regulation and stress responses in Pacific abalone (Haliotis discus hannai), this study was aimed to isolate the genetic determinant of abalone MTF-1 and to examine its expression characteristics under basal and experimentally stimulated conditions. Results: The abalone MTF-1 shared conserved features in zinc-finger DNA binding domain with its orthologs; however, it represented a non-conservative shape in presumed transactivation domain region with the lack of typical motifs for nuclear export signal (NES) and Cys-cluster. Abalone MTF-1 promoter exhibited various transcription factor binding motifs that would be potentially related with metal regulation, stress responses, and development. The highest messenger RNA (mRNA) expression level of MTF-1 was observed in the testes, and MTF-1 transcripts were detected during the entire period of embryonic and early ontogenic developments. Abalone MTF-1 was found to be Cd inducible and highly modulated by heat shock treatment. Conclusion: Abalone MTF-1 possesses a non-consensus structure of activation domains and represents distinct features for its activation mechanism in response to metal overload and heat stress. The activation mechanism of abalone MTF-1 might include both indirect zinc sensing and direct de novo synthesis of transcripts. Taken together, results from this study could be a useful basis for future researches on stress physiology of this abalone species, particularly with regard to heavy metal detoxification and thermal adaptation.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.3
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• pp.163-168
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• 2003

The reactive oxygen species (ROS) are considered to be an important mediator in pancreatic ${\beta}$ cell destruction, thereby triggering the development of insulin-dependent diabetes mellitus. In the present study, HIV-1 Tat-mediated transduction of Cu,Zn-superoxide dismutase (SOD) was investigated to evaluate its protective potential against streptozotocin (STZ)-induced cytotoxicity in insulin-producing MIN6N cells. Tat-SOD fusion protein was successfully delivered into MIN6N cells in a dose-dependent manner and the transduced fusion protein was enzymatically active for 48 h. The STZ induced-cell destruction, superoxide anion radical production, and DNA fragmentation of MIN6N cells were significantly decreased in the cells pretreated with Tat-SOD for 1 h. Furthermore, the transduction of Tat-SOD increased Bcl-2 and heat shock protein 70 (hsp70) expressions in cells exposed to STZ, which might be partly responsible for the effect of Tat-SOD. These results suggest that an increased of free radical scavenging activity by transduction of Tat-SOD enhanced the tolerance of the cell against oxidative stress in STZ-treated MIN6N cells. Therefore, this Tat-SOD transduction technique may provide a new strategy to protect the pancreatic ${\beta}$ cell destruction in ROS-mediated diabetes.