• Molecules and Cells
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• 제37권2호
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• pp.100-108
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• 2014

Salmonella enterica serovar Typhimurium (S. Typhimurium) is an intracellular pathogen that has evolved to survive in the phagosome of macrophages. The periplasmic copper-binding protein CueP was initially known to confer copper resistance to S. Typhimurium. Crystal structure and biochemical studies on CueP revealed a putative copper binding site surrounded by the conserved cysteine and histidine residues. A recent study reported that CueP supplies copper ions to periplasmic Cu,Zn-superoxide dismutase (SodCII) at a low copper concentration and thus enables the sustained SodCII activity in the periplasm. In this study, we investigated the role of CueP in copper resistance at a high copper concentration. We observed that the survival of a cueP-deleted strain of Salmonella in macrophage phagosome was significantly reduced. Subsequent biochemical experiments revealed that CueP specifically mediates the reduction of copper ion using electrons released during the formation of the disulfide bond. We observed that the copper ion-mediated Fenton reaction in the presence of hydrogen peroxide was blocked by CueP. This study provides insight into how CueP confers copper resistance to S. Typhimurium in copper-rich environments such as the phagosome of macrophages.

• Journal of Microbiology and Biotechnology
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• 제28권7호
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• pp.1209-1216
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• 2018

This study aimed to evaluate the antimicrobial activity of 2-phenylethynyl-butyltellurium (PEBT) in Escherichia coli and the relation to its pro-oxidant effect. For this, we carried out the disk diffusion test, minimum inhibitory concentration (MIC) assay, and survival curve analysis. We also measured the level of extracellular reactive oxygen species (ROS), activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), and level of non-protein thiols (NPSH). PEBT at 1.28 and 0.128 mg/disk exhibited antimicrobial capability in the disk diffusion test, with an MIC value of 1.92 mg/ml, whereas PEBT at 0.96, 1.92, and 3.84 mg/ml inhibited bacterial growth after a 9-h exposure. PEBT at 3.84, 1.92, and 0.96 mg/ml increased extracellular ROS production, decreased the intracellular NPSH level, and reduced the SOD and CAT activities. Glutathione or ascorbic acid in the medium protected the bacterial cells from the antimicrobial effect of PEBT. In conclusion, PEBT exhibited antimicrobial activity against E. coli, involving the generation of ROS, oxidation of NPSH, and reduction of the antioxidant defenses in the bacterial cells.

• 한국수산과학회지
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• 제47권6호
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• pp.757-764
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• 2014

Many researchers have studied algae as a source of material having potential biological activities, not least because many marine algae extracts have strong antioxidant properties. In this study, we investigated the anti-inflammatory effects of Pyropia yezoensis extract (PYE) on RAW 264.7 cells by measuring nitric oxide (NO), reactive oxygen species (ROS), superoxide dismutase (SOD), catalase activity, inducible NOS (iNOS), cyclooxygenase-2 (COX-2), nuclear factor-kappa B (NF-${\kappa}B$), interleukin-$1{\beta}$ (1L-$1{\beta}$), and tumor necrosis factor-alpha (TNF-${\alpha}$). PYE decreased the production of intracellular ROS dose-dependently and increased SOD and catalase activity in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. PYE significantly suppressed the production of NO and reduced the expression of iNOS, COX-2, and NF-${\kappa}B$. PYE treatment also inhibited the production of IL-$1{\beta}$ and TNF-${\alpha}$ significantly and reduced the phosphorylation of Akt and MAPK significantly in LPS-stimulated RAW 264.7 cells. These results suggest that PYE has potential anti-oxidant and anti-inflammatory activities.

• 대한임상독성학회지
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• 제15권2호
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• pp.107-115
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• 2017

Purpose: Glehnia littoralis has been used to treat ischemic stroke, phlegm, cough, systemic paralysis, antipyretics and neuralgia. The pharmacological mechanisms of Glehnia littoralis include calcium channel block, coumarin derivatives, anticoagulation, anti-convulsive effect, as well as anti-oxidant and anti-inflammatory effects. Alpha-amanitin (${\alpha}$-amanitin) is a major toxin from extremely poisonous Amanita fungi. Oxidative stress, which may contribute to severe hepatotoxicity was induced by ${\alpha}$-amanitin. The aim of this study was to investigate whether Glehnia littoralis ethyl acetate extract (GLEA) has the protective antioxidant effects on ${\alpha}$-amanitin -induced hepatotoxicity. Methods: Human hepatoma cell line HepG2 cells were pretreated in the presence or absence of GLEA (50, 100 and $200{\mu}g/ml$) for 4 hours, then exposed to $60{\mu}mol/L$ of${\alpha}$-amanitin for an additional 4 hours. Cell viability was evaluated using the MTT method. AST, ALT, and LDH production in a culture medium and intracellular MDA, GSH, and SOD levels were determined. Results: GLEA (50, 100 and $200{\mu}g/ml$) significantly increased the relative cell viability by 7.11, 9.87, and 14.39%, respectively, and reduced the level of ALT by 10.39%, 34.27%, and 52.14%, AST by 9.89%, 15.16%, and 32.84%, as well as LDH by 15.86%, 22.98%, and 24.32% in culture medium, respectively. GLEA could also remarkably decrease the level of MDA and increase the content of GSH and SOD in the HepG2 cells. Conclusion: In the in vitro model, Glehnia littoralis was effective in limiting hepatic injury after ${\alpha}$-amanitin poisoning. Its antioxidant effect is attenuated by antidotal therapy.

• Korean Journal of Acupuncture
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• 제38권1호
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• pp.32-42
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• 2021

Objectives : In this study, we investigated the neuroprotective effects of ethanol extract of Lonicera japonica flower buds (EELJ) on glutamate-induced neurotoxicity in mouse hippocampus-derived neuronal HT22 cells. Methods : After analyzing the cytoprotective effect of EELJ on glutamate in HT22 cells, the inhibitory effect of apoptosis was studied using flow cytometry. In order to analyze the antioxidant efficacy of EELJ, the levels of reactive oxygen species (ROS) and glutathione (GSH) were investigated, and the effects on the activities of superoxide dismutase (SOD) and catalase (CAT) were also analyzed. Furthermore, the effect of EELJ on the expression of apoptosis regulators such as Bax and Bcl-2 in glutamate-treated HT22 cells was investigated. Results : According the current results, pretreatment with EELJ significantly reduced glutamate-induced loss of cell viability and release of lactate dehydrogenase. EELJ also markedly attenuated glutamate-induced generation of intracellular ROS, which was associated with increased levels of GSH, and activity of SOD and CAT in glutamate-stimulated HT22 cells. In addition, EELJ was strikingly inhibited glutamate-induced apoptosis in HT22 cells. Furthermore, the expression of pro-apoptotic Bax was increased and the expression of anti-apoptotic Bcl-2 was decreased in glutamate-treated HT22 cells, while in the presence of EELJ, their expressions were maintained at the control levels. Conclusions : These findings indicate that EELJ protects glutamate-induced cytotoxicity in HT22 hippocampal neurons through antioxidant activity. Therefore, although identification of biologically active substances of EELJ and re-evaluation through animal experiments is necessary, this natural substance is a promising candidate for further research in preventing and treating oxidative stress-mediated neurodegenerative diseases.

• Asian Pacific Journal of Cancer Prevention
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• 제17권9호
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• pp.4267-4273
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• 2016

Previous studies suggested that dithio-carbamates are potent apoptosis and anti-apoptosis inducing agents in various cancer cells. Here, the anti-proliferative and apoptosis inducing effects of a new derivative (2-NDC) from the dithio-carbamate family was examined in human leukemia K562 cells. We use thiazolyl blue tetrazolium bromide (MTT) to measure viability and cell growth inhibition. The 2-NDC showed effects on viability in a dose and time-dependent manner, inhibiting proliferation at concentrations of $10-30{\mu}M$ after 24-48 hours of treatment and increasing values after 72 hours at $40-120{\mu}M$. The cytotoxic effect of the compound was calculated with an $IC_{50}$ of $30{\mu}M$ after 24-hour. Apoptosis induction was confirmed by acridine orange-ethidium bromide (AO/EtBr) staining, DNA fragmentation assay, flow cytometric assessment and also caspase-3 activation assay. Furthermore, enzymes level such as superoxide dismutase (SOD) and catalase (CAT) involved in oxidative stress were evaluated. The results of this study demonstrated insignificant increase of intracellular ROS levels for 24 hours and reduction after 48-72 hours. In addition to reduction of intracellular thiol, caspase-3 like activity was also decreased in a time-dependent manner in cells treated with 2-NDC. Thus 2-NDC can be considered as a good candidate for further pharmaceutical evaluations.

• Tuberculosis and Respiratory Diseases
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• 제46권3호
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• pp.327-337
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• 1999

연구배경: 활성산소종(reactive oxygen species)은 발암 기전의 여러 단계 과정에 관여한다. 대부분의 종양 세포주 및 종양 조직내의 종양 세포는 활성산소종을 생성하는 반면 종양 세포의 catalase, Mn- 및 CuZn-SOD등 기존 항산화 단백의 활성도는 대부분 저하되어 있다. 이로 인한 종양 조직내의 지속적인 산화 스트레스는 종양의 국소 침습 및 전이를 촉진한다. 12-kDa thioredoxin은 glutathione 및 glutaredoxin과 함께 세포내 산화-환원 전위를 조절하여 세포 활성, 증식, 분화 및 산화-환원에 의한 아포토시스 조절에 관여하는 것으로 알려져 있다. 한편 histiocytic lymphoma 세포 (U937, human)에서 14-kDa 및 10-kDa의 eosinophilic cytotoxic enhancing factor(ECEF)로 정제되었으며 호산구 자극의 생물학적 기능은 10-kDa에서 20배 이상 높은 것으로 알려져 있다. 성인 T-세포백혈병, 자궁경부상피세포암 및 간세포암에서 thioredoxin 양이 증가 되어 있고 폐암에서는 thioredoxin mRNA가 증가되어 있는 것으로 알려져 있다. 이에 폐암 조직과 주위 정상 조직을 비교하여 catalase, CuZn-SOD 및 glutathione peroxidase 등 기존 항산화 단백과 thioredoxin 발현 변화를 비교 관찰하고 대식세포에서 산화 스트레스 및 내독소에 의한 thioredoxin 발현 변화를 관찰하고자 하였다. 방 법: 동일한 환자의 폐암 조직과 주변의 정상 폐 조직을 immunoblot 분석으로 catalase, CuZn-SOD, glutathione peroxidase 및 thioredoxin 발현을 비교 관찰하였으며 대식세포인 mouse monocyte-macrophage 세포 (RAW 264.7)에 5 ${\mu}M$ menadione 및 1 ${\mu}g/ml$ endotoxin을 처치하여 thioredoxin 발현을 관찰하였다. 결 과: Immunoblot 분석상 12-kDa의 thioredoxin 발현은 폐암 조직에서 정상 폐조직과 비교하여 의미있는 증가를 보였으나 catalase 및 CuZn-SOD의 발현은 폐암 조직에서 정상 폐조직과 비교하여 감소하였고 glutathione peroxidase의 발현은 일정 하지 않은 변화를 보였다. 절단형(truncated) thioredoxin 역시 폐암에서 증가하였다. Mouse monocyte-macrophage cells에 5 ${\mu}M$ menadione 및 1 ${\mu}g/ml$ endotoxin을 처치하였을때 thioredoxin 발현은 12시간에 최고로 증가하여 48 시간까지 지속되었다. 결 론: 폐암에서 기존의 항산화 단백과는 달리 12-kDa 및 절단형 thioredoxin 발현이 증가하며 이는 종양 조직내의 지속적인 산화 스트레스와 밀접한 연관이 있다. 특히 절단형 thioredoxin의 생물학적 기능을 고려할 때 절단형 thioredoxin 발현 증가는 종양 세포 증식을 통한 종양 성장에 더욱 의미있는 역할하리라고 생각된다.

• 한국식품영양과학회지
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• 제46권11호
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• pp.1293-1299
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• 2017

Epigallocatechin-3-gallate(EGCG)는 녹차에 함유된 flavonoid 계열 화합물로, 녹차의 대표적인 유효성분으로 알려져 있다. 본 연구는 3T3-L1 세포에서 EGCG의 항비만 작용 및 항산화 효소 활성을 평가하였다. EGCG는 지방세포 분화를 유의적으로 억제하였으며, 지방세포 분화와 관련된 단백질인 $C/EBP{\alpha}$와 aP2의 발현을 감소시켰다. 동시에 EGCG는 GSH의 활성을 유도하였으며, 항산화 효소인 SOD, CAT, GPx 및 GR의 활성을 증가시켰다. EGCG는 지방세포 분화 동안 활성산소종의 형성을 감소시켰다. 체내 phase II 효소인 HO-1과 GCLC는 EGCG에 의해 발현이 유도되었다. 따라서 EGCG는 3T3-L1 세포에서 항산화 효소의 활성화를 유도하며 동시에 지방세포로의 분화를 억제하는 것으로 나타났다. 또한, EGCG는 활성산소종의 생성을 억제하였으며, 이는 EGCG의 항산화 작용에 의한 지방세포 분화 억제 작용이 관련이 있는 것으로 판단된다. EGCG에 의한 항비만 효과와 항산화 작용을 연구한 본 연구는 녹차를 활용한 체지방 감소 효능을 지닌 식품 개발에 기초 자료로 활용될 수 있을 것으로 생각된다.

• Nutrition Research and Practice
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• 제17권2호
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• pp.371-385
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• 2023

BACKGROUND/OBJECTIVES: Soy isoflavone (SIF) and soy lecithin (SL) have beneficial effects on many chronic diseases, including neurodegenerative diseases. Regretfully, there is little evidence to show the combined effects of these soy extractives on the impairment of cognition and abnormal cerebral blood flow (CBF). This study examined the optimal combination dose of SIF + SL to provide evidence for improving CBF and protecting cerebrovascular endothelial cells. MATERIALS/METHODS: In vivo study, SIF50 + SL40, SIF50 + SL80 and SIF50 + SL160 groups were obtained. Morris water maze, laser speckle contrast imaging (LSCI), and hematoxylin-eosin staining were used to detect learning and memory impairment, CBF, and damage to the cerebrovascular tissue in rat. The 8-hydroxy-2'-deoxyguanosine (8-OHdG) and the oxidized glutathione (GSSG) were detected. The anti-oxidative damage index of superoxide dismutase (SOD) and glutathione (GSH) in the serum of an animal model was also tested. In vitro study, an immortalized mouse brain endothelial cell line (bEND.3 cells) was used to confirm the cerebrovascular endothelial cell protection of SIF + SL. In this study, 50 µM of Gen were used, while the 25, 50, or 100 µM of SL for different incubation times were selected first. The intracellular levels of 8-OHdG, SOD, GSH, and GSSG were also detected in the cells. RESULTS: In vivo study, SIF + SL could increase the target crossing times significantly and shorten the total swimming distance of rats. The CBF in the rats of the SIF50 + SL40 group and SIF50 + SL160 group was enhanced. Pathological changes, such as attenuation of the endothelium in cerebral vessels were much less in the SIF50 + SL40 group and SIF50 + SL160 group. The 8-OHdG was reduced in the SIF50 + SL40 group. The GSSG showed a significant decrease in all SIF + SL pretreatment groups, but the GSH showed an opposite result. SOD was upregulated by SIF + SL pretreatment. Different combinations of Genistein (Gen)+SL, the secondary proof of health benefits found in vivo study, showed they have effective anti-oxidation and less side reaction on protecting cerebrovascular endothelial cell. SIF50 + SL40 in rats experiment and Gen50 + SL25 in cell test were the optimum joint doses on alleviating cognitive impairment and regulating CBF through protecting cerebrovascular tissue by its antioxidant activity. CONCLUSIONS: SIF+SL could significantly prevent cognitive defect induced by β-Amyloid through regulating CBF. This kind of effect might be attributed to its antioxidant activity on protecting cerebral vessels.

• Parasites, Hosts and Diseases
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• 제39권2호
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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.