• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.1
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• pp.57-67
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• 2019

Particulate matters with a diameter of < $10{\mu}m$ (PM10) exert oxidative stress and inflammatory events in various organs. The purpose of this study was to examine the molecular mechanism of reactive oxygen species (ROS) production induced by PM10 in the human epidermal keratinocytes (HEKs). When cultured HEKs were exposed to PM10, ROS production was induced and it was inhibited by apocynin, an antioxidant. The mRNA expression of NADPH oxidase (NOX) family was analyzed in order to examine their role in PM10-induced ROS production. PM10 increased the mRNA expression of NOX1, NOX2, dual oxidase (DUOX) 1 and DUOX2. HEKs expressed DUOX1 and DUOX2 at higher levels compared to other NOXs. The mRNA expression of dual oxidase maturation factors, DUOXA1 and DUOXA2, was also increased by PM10. We examined whether these calcium-dependent enzymes, DUOX1 and DUOX2, mediate the PM10-induced ROS production. A selective intracellular calcium chelator, BAPTA-AM, attenuated ROS production induced by PM10 or calcium ionophore A23187. The small intereference RNA (siRNA)-mediated down-regulation of DUOX2, but not DUOX1, attenuated the ROS production induced by PM10. PM10 increased the expression of inflammatory cytokines such as interleukin $(IL)-1{\beta}$, IL-6, IL-8 and interferon $(IFN)-{\gamma}$. SiRNA-mediated down-regulation of DUOX2 suppressed the PM10-induced expression of $IFN-{\gamma}$ but not other cytokines. This study suggests that DUOX2 plays a crucial role in ROS production and inflammatory response in PM10-exposed keratinocytes.

• The Korean Journal of Pesticide Science
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• v.2 no.2
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• pp.10-15
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• 1998

The bimolecular inhibition rate constants of carbofuran and N-dimethylphosphinothioyl carbofuran(PSC) to acetylcholinesterase(AChE) were $7.7{\times}10^{5}\;M^{-1}{\cdot}min^{-1}$ and $1.2{\times}10^{3}\;M^{-1}{\cdot}min^{-1}$, respectively. These results showed that PSC required a bioactivation process for its toxic action because it didn't inhibit the target enzyme effectively. The potency of PSC as an inhibitor of AChE increased when PSC and AChE were incubated with microsomes fortified with NADPH compared with microsome alone. Piperonyl butoxide(PBO) addition to these coupled systems greatly reduced the inhibition of the target enzyme by blocking the bioactivation process. In vivo inhibition study of mouse brain AChE, $I_{50}$ value for AChE was 28 mg/kg for PSC and the value increased to 57 mg/kg when PBO was pretreated. This result showed that cytochrome $P_{450}$ would also play a role in the bioactivation process of PSC in vivo. And conversioin of carbofuran from PSC was 55 % in a chemical oxidation system using meta-chloroperoxybenzoic acid. The oxidative activation of PSC to carbofuran was shown to be essential for showing its toxicological action and cytochrome $P_{450}$ was identified as an important enzyme which participated in this process.

• Journal of Ginseng Research
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• v.45 no.6
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• pp.665-675
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• 2021

Background: Ginsenoside Rg1 (Rg1), an active ingredient in ginseng, may be a potential agent for the treatment of Alzheimer's disease (AD). However, the protective effect of Rg1 on neurodegeneration in AD and its mechanism of action are still incompletely understood. Methods: Wild type (WT) and APP/PS1 AD mice, from 6 to 9 months old, were used in the experiment. The open field test (OFT) and Morris water maze (MWM) were used to detect behavioral changes. Neuronal damage was assessed by hematoxylin and eosin (H&E) and Nissl staining. Immunofluorescence, western blotting, and quantitative real-time polymerase chain reaction (q-PCR) were used to examine postsynaptic density 95 (PSD95) expression, amyloid beta (Aβ) deposition, Tau and phosphorylated Tau (p-Tau) expression, reactive oxygen species (ROS) production, and NAPDH oxidase 2 (NOX2) expression. Results: Rg1 treatment for 12 weeks significantly ameliorated cognitive impairments and neuronal damage and decreased the p-Tau level, amyloid precursor protein (APP) expression, and Aβ generation in APP/PS1 mice. Meanwhile, Rg1 treatment significantly decreased the ROS level and NOX2 expression in the hippocampus and cortex of APP/PS1 mice. Conclusions: Rg1 alleviates cognitive impairments, neuronal damage, and reduce Aβ deposition by inhibiting NOX2 activation in APP/PS1 mice.

• Clinical and Experimental Pediatrics
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• v.51 no.10
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• pp.1096-1101
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• 2008

Purpose : Patients with chronic granulomatous disease (CGD) have genetic mutations in a component of the NADPH oxidase enzyme that is necessary for the generation of the superoxide anion. The profound defect in innate immunity is reflected by the patients susceptibility to catalase-positive bacteria and fungi. In addition, CGD patients display signs of persistent inflammation, which is not associated only with deficient superoxide anion production. The aim of this study was to elucidate the cytokine responses in CGD patients after $TNF-{\alpha}$ stimulation. Methods : Heparinized blood samples were collected from 8 CGD patients and 10 healthy volunteers. Monocytes ($1{\times}10^6cell/well$) isolated by the magnet cell isolation system were incubated with a constant amount of $TNF-{\alpha}$ (10 ng/mL) at $37^{\circ}C$ for 6 h. Incubated cells were harvested at 60-min intervals for IL-8 and IL-10 mRNA analysis, and the supernatant was collected at the same intervals to determine IL-8 and IL-10 expression. Monocytes from healthy volunteers were also incubated with antioxidants followed by $TNF-{\alpha}$ stimulation for IL-8 and IL-10 expression. Results : In CGD patients, a high expression of IL-8 together with a significantly higher IL-10 expression than in the healthy controls was seen after $TNF-{\alpha}$ stimulation. Moreover, normal monocytes treated with antioxidants exhibited increased IL-8 responses. Conclusion : The absence of phagocyte-derived reactive oxidants in CGD might be associated with a dysregulated production of pro- and antiinflammatory cytokines. Additional research related to reactive oxidants is needed to clarify the role of cytokines in CGD patients.

• YAKHAK HOEJI
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• v.43 no.6
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• pp.736-742
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• 1999

Antioxidative and cytoprotective effects of tectorigenin and glycitein isolated from the pueraria thunbergiana and its derivative, genistein, were determined. Among these three compounds, tectorigenin and glycitein bearing 6-methoxyl groups in both isoflavones showed significant free radical scavenging activities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and xanthine/xanthine oxidase (XOD) generating superoxide anion radical. Tectorigenin only showed a slight inhibitory effect on XOD. We further studied the inhibitory effects of these isoflavones on the lipid peroxidation in rat liver microsomes induced by enzymatic and non-enzymatic methods. Each of them exhibited inhibitory effect on both ascorbic $acid/Fe^{2+}-{\;}and{\;}ADP/NADPH/Fe^{+3}-induced$ lipid peroxidation. Moreover, tectorigenin exhibited the highest protection of hydrogen peroxide damage on HepG2 and Vero cells among the three isoflavones, in the cytoprotective assay. It was suggested that the pattern of antioxidative and cytoprotective effect of isoflavones could be crucially by the aromatic substitution of oxygen-containing groups.

• Mycobiology
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• v.47 no.1
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• pp.105-111
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• 2019

Many of the fungicides and antibiotics currently available against plant pathogens are of limited use due to the emergence of resistant strains. In this study, we examined the effects of diphenyleneiodonium chloride (DPIC), an inhibitor of the superoxide producing enzyme NADPH oxidase, against fungal and bacterial plant pathogens. We found that DPIC inhibits fungal spore germination and bacterial cell proliferation. In addition, we demonstrated the potent antibacterial activity of DPIC using rice heads infected with the bacterial pathogen Burkholderia glumae which causes bacterial panicle blight (BPB). We found that treatment with DPIC reduced BPB when applied during the initial flowering stage of the rice heads. These results suggest that DPIC could serve as a new and useful antimicrobial agent in agriculture.

• Tuberculosis and Respiratory Diseases
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• v.58 no.3
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• pp.267-276
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• 2005

Background : The transforming growth $factor-{\beta}1$ ($TGF-{\beta}1$) plays a key role in lung fibrosis. However, the molecular mechanisms involved in $TGF-{\beta}1$-induced lung fibrosis are unclear. $TGF-{\beta}1$ is the key inducer of myofibroblast transdifferentiation via de novo synthesis of ${\alpha}-smooth$ muscle actin (${\alpha}-SMA$). Since $TGF-{\beta}1$ signals through reactive oxygen species (ROS) and ROS have been shown to induce accumulation of extracellular matrix (ECM) in various tissues, this study examined if ROS play a role in $TGF-{\beta}1$-induced fibronectin secretion and ${\alpha}-SMA$ expression in human lung fibroblasts, MRC-5 cells. Methods : Growth arrested and synchronized MRC-5 cells were stimulated with $TGF-{\beta}1$ (0.2-10 ng/ml) in the presence or absence of N-acetylcysteine (NAC) or diphenyleneiodonium (DPI) for up to 96 hours. Dichlorofluorescein (DCF)-sensitive cellular ROS were measured by FACScan and secreted fibronectin and cellular ${\alpha}-SMA$ by Western blot analysis. Results : $TGF-{\beta}1$ increased the level of fibronectin secretion and ${\alpha}-SMA$ expression in MRC-5 cells in a dosedependent manner. Both NAC (20 and 30 mM) and DPI (1 and $5{\mu}M$) significantly inhibited $TGF-{\beta}1$-induced fibronectin and ${\alpha}-SMA$ upregulation. The $TGF-{\beta}1$-induced cellular ROS level was also significantly reduced by NAC and DPI. Conclusions : The results suggest that NADPH oxidase-dependent ROS play an important role in $TGF-{\beta}1$-induced fibronectin secretion and ${\alpha}-SMA$ expression in MRC-5 cells, which leads to myofibroblast transdifferentiation and progressive lung fibrosis.

• The Journal of Internal Korean Medicine
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• v.35 no.1
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• pp.92-105
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• 2014

Objectives : Cisplatin is a widely used cancer therapy drug. However, nephrotoxicity resulting in increased oxidative stress is a major side effect of cisplatin chemotherapy, thereby limiting its chemotherapeutic use. Lycium chinense Miller (LCM) has been used as a traditional herbal medicine in various febrile and inflammatory diseases such as night sweat, cough, nosebleed, bronchitis, pulmonary tuberculosis, etc. In this study we investigated the protective and antioxidative potential of LCM against cisplatin-induced nephrotoxicity in rats. Methods : Twenty-four 8-week-old male Wistar rats were divided into four groups: normal untreated; cisplatin treatment only; LCM 10 mg/kg plus cisplatin treatment; and LCM 30 mg/kg plus cisplatin treatment. Twenty-four hours after the last cisplatin injection, all the rats were sacrificed, and serological changes were evaluated. The levels of NF-${\kappa}B$ activity and NOX-4, $p47^{phox}$, $p22^{phox}$, COX-2, iNOS, SOD, catalase expressions were analyzed in Western blot analysis. Results : Cisplatin injection caused an increase in the BUN level, which is a reliable indicator of renal toxicity. The levels of BUN, renal ROS, and renal TBARS were significantly reduced in the LCM groups compared with the cisplatin-only groups. The levels of $p47^{phox}$ and $p22^{phox}$, which are NADPH oxidase subunits, were increased in the cisplatin-only groups, whereas they were decreased in the LCM groups. The levels of renal NF-${\kappa}B$ activity and COX-2, iNOS expressions were increased significantly in the cisplatin-only groups compared with the normal groups, whereas they were decreased in the LCM groups. Compared with the cisplatin-only groups, renal GSH and GSH/GSSG increased in the LCM groups. Also, the administration of LCM increased levels of SOD and catalase as compared with the cisplatin-only groups. Conclusions : These results suggest that LCM protects cisplatin-induced nephrotoxicity via a mechanism that may involves the inhibition of oxidative stress by the activation of antioxidants.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.6
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• pp.491-497
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• 2015

Traumatic brain injury (TBI) is a major cause of mortality and long-term disability, which can decrease quality of life. In spite of numerous studies suggesting that Epigallocatechin-3- gallate (EGCG) has been used as a therapeutic agent for a broad range of disorders, the effect of EGCG on TBI remains unknown. In this study, a weight drop model was established to evaluate the therapeutic potential of EGCG on TBI. Rats were administered with 100 mg/kg EGCG or PBS intraperitoneally. At different times following trauma, rats were sacrificed for analysis. It was found that EGCG (100 mg/kg, i.p.) treatment significantly reduced brain water content and vascular permeability at 12, 24, 48, 72 hour after TBI. Real-time PCR results revealed that EGCG inhibited TBI-induced IL-$1{\beta}$ and TNF-${\alpha}$ mRNA expression. Importantly, CD68 mRNA expression decreasing in the brain suggested that EGCG inhibited microglia activation. Western blotting and immunohistochemistry results showed that administering of EGCG significantly inhibited the levels of aquaporin-4 (AQP4) and glial fibrillary acidic protein (GFAP) expression. TBI-induced oxidative stress was remarkably impaired by EGCG treatment, which elevated the activities of SOD and GSH-PX. Conversely, EGCG significantly reduced the contents of MDA after TBI. In addition, EGCG decreased TBI-induced NADPH oxidase activation through inhibition of $p47^{phox}$ translocation from cytoplasm to plasma membrane. These data demonstrate that EGCG treatment may be an effective therapeutic strategy for TBI and the underlying mechanism involves inhibition of oxidative stress.

• Parasites, Hosts and Diseases
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• v.58 no.3
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• pp.237-247
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• 2020

Dendritic cell is one of the first innate immune cell to encounter T. gondii after the parasite crosses the host intestinal epithelium. T. gondii requires intact DC as a carrier to infiltrate into host central nervous system (CNS) without being detected or eliminated by host defense system. The mechanism by which T. gondii avoids innate immune defense of host cell, especially in the dendritic cell is unknown. Therefore, we examined the role of host PI3K/AKT signaling pathway activation by T. gondii in dendritic cell. T. gondii infection or T. gondii excretory/secretory antigen (TgESA) treatment to the murine dendritic cell line DC2.4 induced AKT phosphorylation, and treatment of PI3K inhibitors effectively suppressed the T. gondii proliferation but had no effect on infection rate or invasion rate. Furthermore, it is found that T. gondii or TgESA can reduce H₂O₂-induced intracellular reactive oxygen species (ROS) as well as host endogenous ROS via PI3K/AKT pathway activation. While searching for the main source of the ROS, we found that NADPH oxidase 4 (NOX4) expression was controlled by T. gondii infection or TgESA treatment, which is in correlation with previous observation of the ROS reduction by identical treatments. These findings suggest that the manipulation of the host PI3K/AKT signaling pathway and NOX4 expression is an essential mechanism for the down-regulation of ROS, and therefore, for the survival and the proliferation of T. gondii.