• Parasites, Hosts and Diseases
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• v.39 no.2
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• pp.133-141
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• 2001

A cDNA of 1.1 kb comprising the gene encoding the peroxiredoxin of Toxo-plasma gondii(TgPrx) has been cloned. The open reading frame of 591 Up was translated into a protein of 196 amino acids with a molecular mass of 25 kDa. Conserved 2 cysteine domains of Phe-Val-Cys-Pro and Glu-Val-Cys-Pro indicated TgPrx belonged to 2-Cys Prx families. TgPrx showed the highest homology with that of Arabidopsis thaliana by 53.9% followed by Entamoeba histolytica with 39.5% by the amino acid sequence alignment. Polyclonal antibody against recombinant TgPrx detected 25 kDa band in T. gondii without binding to host cell proteins TgPrx was located in the cytoplasm of T. gondii extracellularly or intracellularly by immunofluorescence assay. The expression of TgPrx was increased as early as 30 min after the treatment with artemisinin in the intracellular stage, while no changes in those of host Prx I and TgSOD. This result implies that TgPrx may function as an antioxidant protecting the cell from the attack of reactive oxygen intermediates. It is also suggested that TgPrx is a possible target of chemotherapy.

• Nutrition Research and Practice
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• v.9 no.6
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• pp.586-591
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• 2015

BACKGROUND/OBJECTIVES: Reactive oxygen species (ROS) formation is closely related to miconazole-induced heart dysfunction. Although rhamnetin has antioxidant effects, it remained unknown whether it can protect against miconazole-induced cardiomyocyte apoptosis. Thus, we investigated the effects of rhamnetin on miconazole-stimulated H9c2 cell apoptosis. MATERIALS/METHODS: Cell morphology was observed by inverted microscope and cell viability was determined using a WelCount$^{TM}$ cell proliferation assay kit. Miconazole-induced ROS production was evaluated by fluorescence-activated cell sorting with 6-carboxy-2',7'-dichlorofluoroscein diacetate ($H_2DCF$-DA) stain. Immunoblot analysis was used to determine apurinic/apyrimidinic endonuclease 1 (APE/Ref-1) and cleaved cysteine-aspartic protease (caspase) 3 expression. NADPH oxidase levels were measured using real-time polymerase chain reaction. RESULTS: Miconazole (3 and $10{\mu}M$) induced abnormal morphological changes and cell death in H9c2 cells. Rhamnetin enhanced the viability of miconazole ($3{\mu}M$)-treated cells in a dose-dependent manner. Rhamnetin (1 and $3{\mu}M$) treatment downregulated cleaved caspase 3 and upregulated APE/Ref-1 expression in miconazole-stimulated cells. Additionally, rhamnetin significantly reduced ROS generation. CONCLUSIONS: Our data suggest that rhamnetin may have cytoprotective effects in miconazole-stimulated H9c2 cardiomyocytes via ROS inhibition. This effect most likely occurs through the upregulation of APE/Ref-1 and attenuation of hydrogen peroxide levels.

• BMB Reports
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• v.33 no.3
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• pp.234-241
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• 2000

A new type of the human TSA homologous gene was cloned from a HeLa cell cDNA and characterized. The gene product consists of 161 amino acids with a molecular mass of 16,900. The TSA homologous protein, as a new 6th member of the human TSA (hTSA VI), exerted a thioldependent peroxidase activity with the use of thioredoxin system as a physiological electron donor. The values of $V_{max}/K_m$ of hTSA VI for $H_2O_2$ and t-butyl hydroperoxide (t-BOOH) were calculated as $5.53{\times}10^{-2}$ and $3.70{\times}10^{-2}$, respectively. This implies that hTSA VI is a peroxidase, which reduces $H_2O_2$ and t-BOOH. The mutation of $Cys^{47}$ to serine resulted in a complete loss of the peroxidase activity. This suggests that $Cys^{47}$ acts as a primary site of catalysis. The analysis of the tryptic digest derived from hTSA VI revealed that the $Cys^{47}$ exists as a free thiol form. Taken together, these results suggest that the TSA homologous protein is a new type of the human family, which exerts thioredoxin-linked peroxidase activity toward $H_2O_2$ and alkyl hydroperoxide.

• 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.

• Molecules and Cells
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• v.38 no.3
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• pp.229-235
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• 2015

Nicotinamide (NAM) has been shown to suppress reactive oxygen species (ROS) production in primary human fibroblasts, thereby extending their replicative lifespan when added to the medium during long-term cultivation. Based on this finding, NAM is hypothesized to affect cellular senescence progression by keeping ROS accumulation low. In the current study, we asked whether NAM is indeed able to reduce ROS levels and senescence phenotypes in cells undergoing senescence progression and those already in senescence. We employed two different cellular models: MCF-7 cells undergoing senescence progression and human fibroblasts in a state of replicative senescence. In both models, NAM treatment substantially decreased ROS levels. In addition, NAM attenuated the expression of the assessed senescence phenotypes, excluding irreversible growth arrest. N-acetyl cysteine, a potent ROS scavenger, did not have comparable effects in the tested cell types. These data show that NAM has potent antioxidative as well as anti-senescent effects. Moreover, these findings suggest that NAM can reduce cellular deterioration caused by oxidative damage in postmitotic cells in vivo.

• The Plant Pathology Journal
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• v.35 no.6
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• pp.609-622
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• 2019

Sound vibration (SV) treatment can trigger various molecular and physiological changes in plants. Previously, we showed that pre-exposure of Arabidopsis plants to SV boosts its defense response against Botrytis cinerea fungus. The present study was aimed to investigate the changes in the proteome states in the SV-treated Arabidopsis during disease progression. Proteomics analysis identified several upregulated proteins in the SV-infected plants (i.e., SV-treated plants carrying Botrytis infection). These upregulated proteins are involved in a plethora of biological functions, e.g., primary metabolism (i.e., glycolysis, tricarboxylic acid cycle, ATP synthesis, cysteine metabolism, and photosynthesis), redox homeostasis, and defense response. Additionally, our enzyme assays confirmed the enhanced activity of antioxidant enzymes in the SV-infected plants compared to control plants. Broadly, our results suggest that SV pre-treatment evokes a more efficient defense response in the SV-infected plants by modulating the primary metabolism and reactive oxygen species scavenging activity.

• Preventive Nutrition and Food Science
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• v.22 no.2
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• pp.118-123
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• 2017

This study was conducted to investigate the anti-adipogenic activity of esculetin (ECT) which is reported to be attributable to the modulation of antioxidant enzymes during adipogenesis. After six days of ECT treatment of 3T3-L1 cells, lipid accumulation was determined by Oil red O staining. The levels of glutathione (GSH) and reactive oxygen species (ROS), and the activities of antioxidant enzymes including glutathione reductase, glutathione peroxidase (GPx), and catalase were examined. In addition, the protein expression of glutamate-cysteine ligase catalytic subunit (GCLC) and heme oxygenase-1 (HO-1) was measured by Western blot. ECT significantly inhibited lipid accumulation by approximately 80% and ROS production in a concentration-dependent manner. GSH level and GPx activity were increased by ECT by approximately 1.3-fold and 1.7-fold compared to the control group, respectively. GCLC and HO-1 expression were elevated by ECT. These results showed that ECT treatments strongly inhibit adipogenesis, increase GSH level, and upregulate the expression of GCLC and HO-1, possibly by decreasing ROS production in 3T3-L1 cells during adipogenesis.

• Archives of Pharmacal Research
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• v.24 no.4
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• pp.349-354
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• 2001

Curcumin, a dietary pigment in turmeric, posseses anti-carcinogenic and anti-metastatic properties. The present study was conducted to study in vitro chemopreventive effects of curcumin in transformed breast cells. Here, we show that curcumin inhibits H-ras-induced invasive phenotype in MCF10A human breast epithelial cells (H-ras MCF10A) and downregulates matrix metalloproteinase (MMP)-2 dose-dependently. Curcumin exerted cytotoxic effect on H-ras MCF10A cells in a concentration-dependent manner. Curcumin-induced cell death was mainly due to apoptosis in which a prominent downregulation of Bcl-2 and upregulation of Bax were involved. We also suggest a possible involvement of caspase-3 in curcumin-induced apoptosis. Curcumin treatment resulted in the production of reactive oxygen species (ROS) in H-ras MCF10A cells. Apoptotic event by curcumin was significantly inhibited by pretreatment of an antioxidant N-acetyl-$_L$-cysteine (NAC), suggesting redox signaling as a mechanism responsible for curcumin-induced apoptosis in H-ras MCF10A cells. Taken together, our results demonstrate that curcumin inhibits invasion and induces apoptosis, proving the chemopreventive potential of curcumin .

• Archives of Pharmacal Research
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• v.24 no.4
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• pp.342-348
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• 2001

In a course of obtaining more amount of bioactive costunolide and successive phytochemical isolation from Magnolia sieboldii (Magnoliaceae), a novel acyclic monoterpene 1 named deoxygeraniol (2,6(E)-dimethyl-2,6-octadiene) was isolated along with $\beta$-sitosterol 3-O-linoleate (2), trilinolein (3) and high amount of costunolide (4) in the pure state. The structure of compound 1 was determined on the basis of spectroscopic data. Costunolide was found to induce apoptotic cell death in a dose-dependent manner by nucleosomal DNA ladder and flow cytometric analysis. Immunoblot analysis showed that the level of the anti-apoptotic protein, Bcl-2, was decreased, whereas the cleavage of poly-(ADP-ribose) polymerase was, activated furthermore, the N-acetyl-L-cysteine antioxidant effectively prevented costunolide-induced cytotoxicity. These results suggest that costunolide-induced cell death is mediated by reactive oxygen species.

• Molecules and Cells
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• v.39 no.1
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• pp.6-19
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• 2016

Redox signalling comprises the biology of molecular signal transduction mediated by reactive oxygen (or nitrogen) species. By specific and reversible oxidation of redoxsensitive cysteines, many biological processes sense and respond to signals from the intracellular redox environment. Redox signals are therefore important regulators of cellular homeostasis. Recently, it has become apparent that the cellular redox state oscillates in vivo and in vitro, with a period of about one day (circadian). Circadian timekeeping allows cells and organisms to adapt their biology to resonate with the 24-hour cycle of day/night. The importance of this innate biological timekeeping is illustrated by the association of clock disruption with the early onset of several diseases (e.g. type II diabetes, stroke and several forms of cancer). Circadian regulation of cellular redox balance suggests potentially two distinct roles for redox signalling in relation to the cellular clock: one where it is regulated by the clock, and one where it regulates the clock. Here, we introduce the concepts of redox signalling and cellular timekeeping, and then critically appraise the evidence for the reciprocal regulation between cellular redox state and the circadian clock. We conclude there is a substantial body of evidence supporting circadian regulation of cellular redox state, but that it would be premature to conclude that the converse is also true. We therefore propose some approaches that might yield more insight into redox control of cellular timekeeping.