• Biomolecules & Therapeutics
• /
• 제20권2호
• /
• pp.144-151
• /
• 2012

The molecular mechanisms by which a variety of naturally-occurring dietary compounds exert chemopreventive effects have been a subject of intense scientific investigations. Induction of phase II detoxification and anti-oxidant enzymes through activation of Nrf2/ARE-dependent gene is recognized as one of the major cellular defense mechanisms against oxidative or xenobiotic stresses and currently represents a critical chemopreventive mechanism of action. In the present review, the functional significance of Keap1/Nrf2 protein module in regulating ARE-dependent phase II detoxification and anti-oxidant gene expression is discussed. The biochemical mechanisms underlying the phosphorylation and expression of Keap1/Nrf2 proteins that are controlled by the intracellular signaling kinases and ubiquitin-mediated E3 ligase system as well as control of nucleocytoplasmic translocation of Nrf2 by its innate nuclear export signal (NES) are described.

• 생약학회지
• /
• 제33권4호통권131호
• /
• pp.359-363
• /
• 2002

Antioxidant properties of the extracts of Acanthopanax senticosus were investigated. The dried roots, stems or leaves were extracted with hot water or ethanol each. The ethanol extracts exhibited higher potency than aqueous extracts in scavenging free radicals and in inhibiting microsomal lipid peroxidation: the aqueous extracts of stems showed higher anti-oxidant effects than the root extracts. Copper-mediated LDL oxidation was also protected by the ethanol exlracts: antioxidant effects of the extracts tested were stronger than ascorbic acid, but not butylated hydroxytoluene. The activity of angiotensin converting enzyme was effectively suppressed by the aqueous extracts of the stems. However, in vivo antioxidant properties of the ethanol extracts of the stems did not seem to be significant, judged from the lipid peroxide values of serum and liver in normal mice. Thus, the ethanol extracts of the stems were shown to be more potent for protecting biological systems against various oxidant stresses in vitro, but not in vivo.

• 한국식품영양과학회지
• /
• 제46권1호
• /
• pp.18-25
• /
• 2017

본 연구는 삼채의 조추출물과 유기용매 분획물들을 가지고 DPPH 라디칼 소거 활성에 의한 항산화 활성 검색 결과 디클로로메탄($CH_2Cl_2$) 분획물과 에틸아세테이트(EtOAc) 분획물에서 라디칼 소거 활성을 나타냈으며, xanthine oxidase 억제 효과는 DPPH 활성 라디칼 소거 활성에서 제일 뛰어났던 에틸아세테이트 분획물에서, superoxide 소거 활성은 헥산(n-hexane) 분획물에서 활성이 나타났다. RAW 264.7 세포에 lipopolysaccharide로 자극을 주고 삼채 주정 추출물 및 유기용매 분획물들을 처리하여 확인해본 결과, 조추출물과 물 분획물을 제외한 나머지 유기용매 분획물에서 염증유발 인자(NO, $PGE_2$, iNOS, COX-2, IL-6 및 $IL-1{\beta}$) 생성억제 효과가 나타났으며, 그중 디클로로메탄 분획물과 에틸아세테이트 분획물에서 억제 효과를 확인할 수 있었다. 본 실험 결과 삼채 조추출물과 유기용매 분획물에서 항산화 효과 및 염증 유발 인자의 생성 억제 효과가 나타났으며, 이러한 결과 삼채에서 유효성분 추출을 통한 항산화, 항염증 물질의 연구 또는 예방하거나 치료할 수 있는 염증 억제 성분의 분리 및 그 작용기전 연구에 중요한 기초 자료가 될 것이라 생각한다.

• Nutrition Research and Practice
• /
• 제8권5호
• /
• pp.526-532
• /
• 2014

BACKGROUND/OBJECTIVES: Acanthopanax sessiliflorus is a native Korean plant and used as a traditional medicine or an ingredient in many Korean foods. The free radical theory of aging suggests that cellular oxidative stress caused by free radicals is the main cause of aging. Free radicals can be removed by cellular anti-oxidants. MATERIALS/METHODS: Here, we examined the anti-oxidant activity of Acanthopanax sessiliflorus extract both in vitro and in vivo. Survival of nematode C. elegans under stress conditions was also compared between control and Acanthopanax sessiliflorus extract-treated groups. Then, anti-aging effect of Acanthopanax sessiliflorus extract was monitored in C. elegans. RESULTS: Stem extract significantly reduced oxidative DNA damage in lymphocyte, which was not observed by leaves or root extract. Survival of C. elegans under oxidative-stress conditions was significantly enhanced by Acanthopanax sessiliflorus stem extract. In addition, Acanthopanax sessiliflorus stem increased resistance to other environmental stresses, including heat shock and ultraviolet irradiation. Treatment with Acanthopanax sessiliflorus stem extract significantly extended both mean and maximum lifespan in C. elegans. However, fertility was not affected by Acanthopanax sessiliflorus stem. CONCLUSION: Different parts of Acanthopanax sessiliflorus have different bioactivities and stem extract have strong anti-oxidant activity in both rat lymphocytes and C. elegans, and conferred a longevity phenotype without reduced reproduction in C. elegans, which provides conclusive evidence to support the free radical theory of aging.

• 한국자원식물학회지
• /
• 제31권4호
• /
• pp.303-311
• /
• 2018

본 연구는 좁은잎천선과나무 잎 추출물을 식의약품 소재 등 천연물 소재로 활용하기 위하여 항산화 및 항염증 활성에 대한 예비 평가를 기술하였다. 좁은잎천선과나무는 70% 에탄올을 사용하여 추출한 다음 헥산, 디클로로메탄, 에틸아세테이트 및 부탄올을 사용하여 순차적으로 분획하였다. 항산화 및 항염증제 효과를 효과적으로 스크리닝하기 위해 좁은잎천선과나무 잎 추출물이 산화 스트레스(DPPH, xanthine oxidase and superoxide) 생성에 미치는 억제 효과를 확인하였다. 또한, LPS로 활성화된 대식세포 RAW 264.7 세포에서 염증성 인자(NO, iNOS, COX-2, $PGE_2$, IL-6 and $IL-1{\beta}$)의 생성에 대한 좁은잎천선과나무 잎 추출물의 억제 효과를 확인하였다. 좁은잎천선과 나무 잎 추출물의 용매분획물 중 디클로로메탄과 에틸아세테이트 분획물은 산화 스트레스(DPPH, xanthine oxidase and superoxide)의 생성 감소가 있었고, 좁은잎천선과나무 잎 추출물의 헥산과 디클로로메탄 분획물은 염증 유발인자(NO, iNOS, COX-2, $PGE_2$, IL-6, and $IL-1{\beta}$)의 생성을 억제하였다. 또한, 디클로로메탄 분획물은 염증성 사이토카인($TNF-{\alpha}$, IL-6, and $IL-1{\beta}$)의 생성을 억제하였다. 이러한 결과는 좁은잎천선과나무 잎 추출물이 산화 스트레스 및 염증 유발 인자에 유의한 영향을 미치고 있어 산화방지제 및 항염증제와 같은 천연물 소재로 활용될 수 있을 것으로 사료된다.

• Mycobiology
• /
• 제42권1호
• /
• pp.52-58
• /
• 2014

A nucleoside diphosphate-linked moiety X (Nudix) hydrolase-like gene, YSA1, has been identified as one of the gromwell plant extract-responsive genes in Cryptococcus neoformans. Ysa1 is known to control intracellular concentrations of ADP-ribose or O-acetyl-ADP-ribose, and has diverse biological functions, including the response to oxidative stress in the ascomycete yeast, Saccharomyces cerevisiae. In this study, we characterized the role of YSA1 in the stress response and adaptation of the basidiomycete yeast, C. neoformans. We constructed three independent deletion mutants for YSA1, and analyzed their mutant phenotypes. We found that ysa1 mutants did not show increased sensitivity to reactive oxygen species-producing oxidative damage agents, such as hydrogen peroxide and menadione, but exhibited increased sensitivity to diamide, which is a thiol-specific oxidant. Ysa1 was dispensable for the response to most environmental stresses, such as genotoxic, osmotic, and endoplasmic reticulum stress. In conclusion, modulation of YSA1 may regulate the cellular response and adaptation of C. neoformans to certain oxidative stresses and contribute to the evolution of antifungal drug resistance.

• Molecules and Cells
• /
• 제26권6호
• /
• pp.616-620
• /
• 2008

Maintaining redox balance is one of the crucial requirements for a cell to endure stress from the outside. Dehydroascorbate reductase (DHAR; EC 1.8.5.1) plays an important role in the ascorbate-glutathione cycle; one of the major ROS scavenging systems in most known biological systems. A cDNA clone of the DHAR gene from Oryza sativa (OsDHAR) was isolated and overexpressed in Escherichia coli BL21 (DE3) strain from the pET-28a(+) expression vector. The OsDHAR transformed E. coli cells showed significantly higher DHAR activity and a lower level of ROS than the E. coli cells transformed by an empty pET-28a(+) vector. Also, the DHAR-overexpressing E. coli strain was more tolerant to oxidant- and heavy metal-mediated stress conditions than the control E. coli strain. The results suggest that the overexpressed rice DHAR gene effectively functions in a prokaryotic system and provide protection to various oxidative stresses.

• Mass Spectrometry Letters
• /
• 제1권1호
• /
• pp.25-28
• /
• 2010

The high-throughput identification and accurate quantification of proteins are essential strategies for exploring cellular functions and processes in quantitative proteomics. Stable isotope tagging is a key technique in quantitative proteomic research, accompanied by automated tandem mass spectrometry. For the differential proteome analysis of mouse neuronal cell lines, we used a multiplexed isobaric tagging method, in which a four-plex set of amine-reactive isobaric tags are available for peptide derivatization. Using the four-plex set of isobaric tag for relative and absolute quantitation (iTRAQ) reagents, we analyzed the differential proteome in several stroke time pathways (0, 4, and 8 h) after the mouse neuronal cells have been stressed using a glutamate oxidant. In order to obtain a list of the differentially expressed proteins, we selected those proteins which had apparently changed significantly during the stress test. With 95% of the peptides showing only a small variation in quantity before and after the test, we obtained a list of eight up-regulated and four down-regulated proteins for the stroke time pathways. To validate the iTRAQ approach, we studied the use of oxidant stresses for mouse neuronal cell samples that have shown differential proteome in several stroke time pathways (0, 4, and 8 h). Results suggest that histone H1 might be the key protein in the oxidative injury caused by glutamate-induced cytotoxicity in HT22 cells.

• Journal of Ginseng Research
• /
• 제32권1호
• /
• pp.8-14
• /
• 2008

스트레스 반응은 위급 상황에서만 활성화 되는 것이 아니라 우리 주변을 둘러싼 모든 사회적, 물리적 환경에 의해 끊임없이 기인된다. 예를 들어 소음, 강한 빛과 열, 주거의 공간 등과 같은 물리적 환경과 타인과의 관계, 부당한 대우, 규칙, 형식과 같은 사회적 관계 이 그것이다. 고려 인삼은 항스트레스 작용을 한다고 알려져 있으나 현재까지 대부분의 연구는 인삼 엑기스 또는 총 사포닌을 투여 시 나타나는 물리화학적인 척도 (수영 시간, 뜨거움에 대한 반응, 포도당 및호르몬 수준 등)를 측정하였으며 뇌에서 ginsenoside의 기능연구는 매우 미흡한 수준이다. 특히 신호전달, 전사체 (transcriptome),proteomics, system biology와 같은 분자생물학적인 방법을 이용한 기전 연구는 전혀 수행된 바 없다. 따라서 인삼의 항 스트레스 반응 기전을 이해하기 위해서는 인삼투여 후 뇌에서 나타나는 분자적 변화에 대한 연구가 앞으로 요구된다. 또한 microarray 등의 분자생물학적 기법을 이용하여 인삼 투여에 의해 반응하는 유전자를 발굴함으로써 이러한 인자들이 인삼 효능 시험 등에 지표로 응용될 수 있을것이다.

• Bulletin of the Korean Chemical Society
• /
• 제19권11호
• /
• pp.1202-1206
• /
• 1998

We have explored the impact of altering the Ras-cAMP pathway on cell survival upon oxidative exposures. A hyperactivated Ras mutant of Saccharomyces cerevisiae, intrinsically more sensitive to heat shock than the wild type, was investigated with regard to oxidative stress. In this paper we report that the response of iral, ira2-deleted mutant (IR2.53) to an oxidant, such as hydrogen peroxide (H2O2) or menadione is more sensitive than that of the wild type. IR2.53 showed a dramatic decrease in survival rate when challenged with 0.1 mM H2O2 for 30 min. The greater sensitivity of IR2.53 was also noticed with treatment of 0.01 mM menadione. Prior to oxidative stresses by these oxidants, both the wild type and the mutant were preconditioned with a mild heat shock (37 ℃, 30 min), resulting in improved survivals against oxidative stresses. Rescue of IR2.53 from menadione stress by heat pretreatment was more clearly demonstrated than that from H2O2 treatment. On the other hand, no significant difference was observed between the wild type and the IR2.53 mutant in their survival rates upon paraquat treatments. These findings imply that the mechanism by which H2O2 and menadione put forth their oxidative effects may be closely associated with the cAMP-Ras pathway whereas that of paraquat is independent of the Ras pathway. Finally, the level of glutathione (GSH) was measured enzymatically as an indicator of antioxidation and compared with the survival rate. Taken all these together, this study provides an insight into a mechanism of the Ras pathway regulated by several oxidants and suggests that the Ras pathway plays a crucial role in protection of cell damage following oxidative stress.