• Molecules and Cells
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• v.41 no.5
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• pp.401-412
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• 2018

Oxymatrine (OMT) often used in treatment for chronic hepatitis B virus infection in clinic. However, OMT-induced liver injury has been reported. In this study, we aim to investigate the possible mechanism of OMT-induced hepatotoxicity in human normal liver cells (L02). Exposed cells to OMT, the cell viability was decreased and apoptosis rate increased, the intracellular markers of oxidative stress were changed. Simultaneously, OMT altered apoptotic related proteins levels, including Bcl-2, Bax and pro-caspase-8/-9/-3. In addition, OMT enhanced the protein levels of endoplasmic reticulum (ER) stress makers (GRP78/Bip, CHOP, and cleaved-Caspase-4) and phosphorylation of c-Jun N-terminal kinase (p-JNK), as well as the mRNA levels of GRP78/Bip, CHOP, caspase-4, and ER stress sensors (IREI, ATF6, and PERK). Pre-treatment with Z-VAD-fmk, JNK inhibitor SP600125 and N-acetyl-l-cysteine (NAC), a ROS scavenger, partly improved the survival rates and restored OMT-induced cellular damage, and reduced caspase-3 cleavage. SP600125 or NAC reduced OMT-induced p-JNK and NAC significantly lowered caspase-4. Furthermore, 4-PBA, the ER stress inhibitor, weakened inhibitory effect of OMT on cells, on the contrary, TM worsen. 4-PBA also reduced the levels of p-JNK and cleaved-caspase-3 proteins. Therefore, OMT-induced injury in L02 cells was related to ROS mediated p-JNK and ER stress induction. Antioxidant, by inhibition of p-JNK or ER stress, may be a feasible method to alleviate OMT-induced liver injury.

• Radiation Oncology Journal
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• v.24 no.4
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• pp.272-279
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• 2006

$\underline{Purpose}$: This study investigated the influence of irradiation and cisplatin on PrxI & PrxII expression and on their survival rates (SR) in SK-N-BE2C and Rat2 cell lines. $\underline{Materials\;and\;Methods}$: The amount of PrxI & PrxII production with or without N-acetyl-L-cysteine (NAC) pretreatment was studied using a western blot after 20 Gy irradiation to determine the degree of inhibition of ROS accumulation. In addition, the amount of PrxI & PrxII production after cisplatin and after combination with cisplatin and 20 Gy irradiation was studied. The SRs of the cell lines in SK-N-BE2C and Rat 2 cells, applied with 20 Gy irradiation only, with various concentrations of cisplatin and with the combination of both, were studied. The 20 Gy irradiation-only group and the combination group were each subdivided according to NAC pretreatment, and corresponding SRs were observed at 2, 6, 12 and 48 hours after treatment. $\underline{Results}$: Compared with the control group, the amount of PrxI in SK-N-BE2C increased up to 60 minutes after irradiation and slightly increased after irradiation with NAC pretreatment 60 minutes. It did not increase in Rat2 after irradiation regardless of NAC pretreatment. PrxII in SK-N-BE2C and Rat2 was not increased after irradiation regardless of NAC pretreatment. The amounts of PrxI and PrxII in SK-N-BE2C and Rat2 were not increased either with the cisplatin-only treatment or the combination treatment with cisplatin and irradiation. SRs of irradiation group with or without NAC pretreatment and the combination group with or without NAC pretreatment were compared with each other in SK-N-BE2C and Rat2. SR was significantly high for the group with increased amount of PrxI, NAC pretreatment and lower the cisplatin concentration. SR of the group in SK-N-BE2C which had irradiation with NAC pretreatment tended to be slightly higher than the group who had irradiation without NAC pretreatment. SR of the group in Rat2 which had irradiation with NAC pretreatment was significantly higher than that the group which had irradiation without NAC pretreatment. Compared to the combination group, the irradiation-only group revealed statistically significant SR decrease with the maximal difference at 12 hours. However, at 48 hours the SR of the combination group was significantly lower than the irradiation-only group. $\underline{Conclusion}$: PrxI is suggested to be an antioxidant enzyme because the amount of PrxI was increased by irradiation but decreased pretreatment NAC, a known antioxidants. Furthermore, cisplatin may inhibit PrxI production which may lead to increase cytotoxicity of irradiation. The expression of PrxI may play an important role in cytotoxicity mechanism caused by irradiation and cisplatin.

• BMB Reports
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• v.45 no.3
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• pp.147-152
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• 2012

Methylglyoxal (MG) was identified as an intermediate in non-enzymatic glycation and increased levels were reported in patients with diabetes. In this study, we evaluated the effects of MG on the modification of ferritin. When ferritin was incubated with MG, covalent crosslinking of the protein increased in a time- and MG dose-dependent manner. Reactive oxygen species (ROS) scavengers, $N-acetyl-_L-cysteine$ and thiourea suppressed the MG-mediated ferritin modification. The formation of dityrosine was observed in MG-mediated ferritin aggregates and ROS scavengers inhibited the formation of dityrosine. During the reaction between ferritin and MG, the generation of ROS was increased as a function of incubation time. These results suggest that ROS may play a role in the modification of ferritin by MG. The reaction between ferritin and MG led to the release of iron ions from the protein. Ferritin exposure to MG resulted in a loss of arginine, histidine and lysine residues. It was assumed that oxidative damage to ferritin caused by MG may induce an increase in the iron content in cells, which is deleterious to cells. This mechanism, in part, may provide an explanation or the deterioration of organs under diabetic conditions.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1079-1085
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• 2008

The chemopreventive activity of sulforaphane (SFN) occurs through its inhibition of carcinogen-activating enzymes and its induction of detoxification enzymes. However, the exact mechanisms by which SFN exerts its anti-carcinogenic effects are not fully understood. Therefore, the mechanisms underlying the cytoprotective effects of SFN were examined in MCF-7 breast cancer cells. Exposure of cells to SFN (10 ${\mu}M$) induced a transcriptional change in the AKR1C3 gene, which is one of aldo-keto reductases (AKRs) family that is associated with detoxification and antioxidant response. Further analysis revealed that SFN elicited a dose- and time-dependent increase in the expression of both the NRF2 and AKR1C3 proteins. Moreover, this up-regulation of AKR1C3 was inhibited by pretreatment with antioxidant, N-acetyl-L-cysteine (NAC), which suggests that the up-regulation of AKR1C3 expression induced by SFN involves reactive oxygen species (ROS) signaling. Furthermore, pretreatment of cells with LY294002, a pharmacologic inhibitor of phosphatidylinositol 3-kinase (PI3K), suppressed the SFN-augmented Nrf2 activation and AKR1C3 expression; however, inhibition of PKC or MEK1/2 signaling with $G\ddot{o}6976$ or PD98059, respectively, did not alter SFN-induced AKR1C3 expression. Collectively, these data suggest that SFN can modulate the expression of the AKR1C3 in MCF-7 cells by activation of PI3K via the generation of ROS.

• Korean Journal of Veterinary Research
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• v.59 no.4
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• pp.195-199
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• 2019

Disulfiram (DSF) is a member of the dithiocarbamate family that can bind copper. Recent studies have shown that DSF has anti-cancer activities, but the mechanism has not been clarified. Therefore, it is important to study the action mechanism of DSF to maximize its anticancer effects. A human leukemia cell line, HL-60, was used in this study. HL-60 cells were treated with DSF and the cellular metabolic activity was measured. DSF increased the cell death of HL-60 cells in annexin V-fluorescein isothiocyanate/propidium iodide staining analysis. In addition, DSF decreased the mitochondrial membrane potential (MMP) of the HL-60 cells. The cytotoxicity of DSF on HL-60 cells was observed at 0.4 μM. Interestingly, the reduction of MMP by DSF was recovered by N-acetyl-L-cysteine, an inhibitor of reactive oxygen species (ROS) production. This suggests that the decrease in MMP by DSF is closely related to the production of ROS in HL-60 cells, which indicates the relationship between the apoptosis of HL-60 cells by DSF and the role of the mitochondria. This study provides clinicians and researchers with valuable information regarding the anti-cancer activity of DSF in terms of the action mechanism.

• YAKHAK HOEJI
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• v.52 no.1
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• pp.48-55
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• 2008

CD29 $({\beta}1-integrins)$ is one of major adhesion molecules involved in regulating cell adhesion, migration and morphological changes. In this study, we investigated the regulatory role of CD29 in monocytic functions using monocytic cell line U937 cells. CD29 was found to be one of highly expressed membrane proteins in U937 cells, according to flow cytometric analysis. The activation of CD29 by agonistic antibody MEM101A and extracellular matrix protein (ECM) fibronectin strongly induced cell-cell and cell-fibronectin adhesions. However, blocking antibodies to CD98 and CD147 showed different inhibitory features in these two adhesion events. Furthermore, U0126, an ERK inhibitor, only blocked cell-cell adhesion but not cell-fibronectin adhesion, indicating that cell-cell or cell-fibronectin adhesion events may be regulated by different molecular mechanisms. Meanwhile, CD29 activation also enhanced ROS generation but not phagocytic ability, and similarly radical scavenger N-acetyl-L-cysteine strongly blocked CD29-mediated cell-cell adhesion, implying that ROS may play a critical role in up-regulating cell-cell adhesion. Therefore, our data suggest that the activation of CD29 may be critically involved in regulating monocytic cell-mediated cell-cell adhesion and ROS generation.

• BMB Reports
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• v.46 no.1
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• pp.59-64
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• 2013

Signal transducer and activator of transcription 3 (STAT3) and telomerase are considered attractive targets for anticancer therapy. The in vitro anticancer activity of the gold(I) compound auranofin was investigated using MDA-MB 231 human breast cancer cells, in which STAT3 is constitutively active. In cell culture, auranofin inhibited growth in a dose-dependent manner, and N-acetyl-L-cysteine (NAC), a scavenger of reactive oxygen species (ROS), markedly blocked the effect of auranofin. Incorporation of 5-bromo-2'-deoxyuridine into DNA and anchorage-independent cell growth on soft agar were decreased by auranofin treatment. STAT3 phosphorylation and telomerase activity were also attenuated in cells exposed to auranofin, but NAC pretreatment restored STAT3 phosphorylation and telomerase activity in these cells. These findings indicate that auranofin exerts in vitro antitumor effects in MDA-MB 231 cells and its activity involves inhibition of STAT3 and telomerase. Thus, auranofin shows potential as a novel anticancer drug that targets STAT3 and telomerase.

• Toxicological Research
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• v.16 no.3
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• pp.179-185
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• 2000

Zinc is known to generate reactive oxygen species (ROS) including superoxide anion and hydrogen peroxide ($H_2O_2$), which eventually contribute to cytotoxicity in a variety of cell types. Here in, we demonstrated that zinc decreased the viability of C6 glial cells in a time and dose-dependent manner, which was revealed as apoptosis characterized by ladder-pattern fragmentation of genomic DNA. chromatin condensation and DNA fragmentation in Hoechst dye staining. Zinc-induced apoptosis of C6 glial cells was prevented by the addition of catalase and antioxidants including reduced glutathione (GSH), N-acetyl-L-cysteine (NAC) and pyrrolidinedithiocarbamate (PDTC). Wefurther confirmed that zinc decreased intrac-ellular levels of GSH and generated $H_2O_2$in C6 glial cells. Moreover, antioxidants also decreased the generation of zinc-induced $H_2O_2$ in C6 glial cells. These data indicated that zinc-induced the apoptotic death of C6 glial cells via generation of reactive oxygen species such as $H_2O_2$.

• Toxicological Research
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• v.33 no.3
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• pp.219-224
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• 2017

Lipin1 was identified as a phosphatidate phosphatase enzyme, and it plays a key role in lipid metabolism. Since free radicals contribute to metabolic diseases in the liver, this study investigated the effects of free radicals on the regulation of Lipin1 expression in Huh7 and AML12 cells. Hydrogen peroxide induced mRNA and protein expression of Lipin1 in Huh7 cells, which was assayed by quantitative RT-PCR and immunoblotting, respectively. Induction of Lipin1 by hydrogen peroxide was confirmed in AML12 cells. Hydrogen peroxide treatment significantly increased expression of sterol regulatory element-binding protein (SREBP)-2, but not SREBP-1. Moreover, nuclear translocation of SREBP-2 was detected after hydrogen peroxide treatment. Hydrogen peroxide-induced Lipin1 or SREBP-2 expression was significantly reduced by N-acetyl-$\small{L}$-cysteine treatment, indicating that reactive oxygen species (ROS) were implicated in Lipin1 expression. Next, we investigated whether the hypoxic environments that cause endogenous ROS production in mitochondria in metabolic diseases affect the expression of Lipin1. Exposure to hypoxia also increased Lipin1 expression. In contrast, pretreatment with antioxidants attenuated hypoxia-induced Lipin1 expression. Collectively, our results show that ROS activate SREBP-2, which induces Lipin1 expression.

• The Journal of Korean Medicine
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• v.37 no.2
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• pp.76-84
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• 2016

Objectives: We evaluated the anti-fatigue effects of Rh2-enriched Korean ginseng (Ginseng Rh2+) using a forced exercise-induced chronic fatigue mouse model. Methods: ICR male mice were subjected to running wheel for 1 h, 5 days/week during 4 weeks, and running velocity was gradually increased. Each running session was followed by oral administration of distilled water, Ginseng Rh2+ (150 or 300 mg/kg), or N-acetyl-L-cysteine (NAC, 100 mg/kg) 1 h later. The exercise tolerance and forced swimming test were performed to evaluate the fatigue condition. Results: Chronic forced exercise reduced the physical activity, as evidenced by the behavioral tests, which were notably ameliorated by Ginseng Rh2+ treatment. Ginseng Rh2+ treatment also attenuated the alterations of energy metabolism and oxidative stress in skeletal muscle tissues and/or sera, including malondialdehyde (MDA), lactate concentration and its related factors (lactate dehydrogenase, blood urea nitrogen, and glucose levels). Conclusion: These findings strongly suggest that Ginseng Rh2+ exerts a potent anti-fatigue effect through modulation of energy metabolism and oxidative response.