• Biomolecules & Therapeutics
• /
• 제20권1호
• /
• pp.57-61
• /
• 2012

The matrix metalloproteinase (MMP) family is involved in the breakdown of the extracellular matrix during normal physiological processes such as embryonic development, reproduction, and tissue remodeling, as well as in disease processes such as pathological aging, arthritis, and metastasis. Oxidative conditions generate reactive oxygen species (ROS) (e.g., hydrogen peroxide [$H_2O_2$]) in cells, which subsequently induce the synthesis of matrix metalloproteinase-1 (MMP-1). MMP-1, an interstitial collagenase, in turn stimulates an aging phenomenon. In this study, baicalein (5,6,7-trihydroxyfl avone) was investigated for its in vitro activity against $H_2O_2$-induced damage using a human skin keratinocyte model. Baicalein pretreatment signifi cantly inhibited $H_2O_2$-induced up-regulation of MMP-1 mRNA, MMP-1 protein expression and MMP-1 activity in cultured HaCaT keratinocytes. In addition, baicalein decreased the transcriptional activity of activator protein-1 (AP-1) and the expression of c-Fos and c-Jun, both components of the heterodimeric AP-1 transcription factor. Furthermore, baicalein reduced phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun-N-terminal kinase (JNK), which are upstream of the AP-1 transcription factor. The results of this study suggest that baicalein is involved in the inhibition of oxidative stress-induced expression of MMP-1 via inactivation of the ERK/JNK/AP-1 signaling pathway.

• 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.

• Journal of Photoscience
• /
• 제9권2호
• /
• pp.142-145
• /
• 2002

A strict anaerobe, Prevotella melaninogenica is highly sensitive to oxidative stress. Oxidative stress such as exposure to oxygen or addition of hydrogen peroxide, increased 8-hydroxydeoxyguanosine (80HdG), a typical of oxidative DNA damage, and decreased the bacterial cell survival rate. We could detect the generation of reactive oxygen species in P. melaninogenica after exposure to oxygen. UVA irradiation also increased 80HdG in the bacterium. On the other hand, such oxidative stress did not increase 80HdG in a facultative anaerobe. These findings suggest that P. melaninogenica is a suitable material to study the biological effects of oxidative stress, to evaluate antioxidants, and to study the effects of oxygen or reactive oxygen species on molecular evolution.

• Journal of Microbiology and Biotechnology
• /
• 제28권1호
• /
• pp.145-156
• /
• 2018

Most eukaryotic peroxiredoxins (Prxs) are readily inactivated by a high concentration of hydrogen peroxide ($H_2O_2$) during catalysis owing to their "GGLG" and "YF" motifs. However, such oxidative stress sensitive motifs were not found in the previously identified filamentous fungal Prxs. Additionally, the information on filamentous fungal Prxs is limited and fragmentary. Herein, we cloned and gained insight into Aspergillus nidulans Prx (An.PrxA) in the aspects of protein properties, catalysis characteristics, and especially $H_2O_2$ tolerability. Our results indicated that An.PrxA belongs to the newly defined family of typical 2-Cys Prxs with a marked characteristic that the "resolving" cysteine ($C_R$) is invertedly located preceding the "peroxidatic" cysteine ($C_P$) in amino acid sequences. The inverted arrangement of $C_R$ and $C_P$ can only be found among some yeast, bacterial, and filamentous fungal deduced Prxs. The most surprising characteristic of An.PrxA is its extraordinary ability to resist inactivation by extremely high concentrations of $H_2O_2$, even that approaching 600 mM. By screening the $H_2O_2$-inactivation effects on the components of Prx systems, including Trx, Trx reductase (TrxR), and Prx, we ultimately determined that it is the robust filamentous fungal TrxR rather than Trx and Prx that is responsible for the extreme $H_2O_2$ tolerence of the An.PrxA system. This is the first investigation on the effect of the electron donor partner in the $H_2O_2$ tolerability of the Prx system.

• 한국식품과학회지
• /
• 제44권1호
• /
• pp.82-88
• /
• 2012

감국 에탄올 추출물이 $H_2O_2$로 유도한 산화적 스트레스 상황에서 MC3T3-E1 조골세포의 증식 및 분화, ROS 생성 및 염증 매개성 cytokine인 TNF-${\alpha}$ 생성 등에 미치는 영향을 분석하였다. $H_2O_2$로 유도한 산화적 스트레스 상황에서 감국 에탄올 추출물은 30-100 ${\mu}g/mL$ 농도 범위에서 조골세포의 증식을 유의적으로 증가시켰다. 또한, 감국 에탄올 추출물 200 ${\mu}g/mL$ 농도에서 ALP 활성이 약 1.5배 유의적인 증가를 나타냈다. 그러나 collagen 합성에는 유의적 차이를 보이지 않았다. Mineralization 측정에서는 200 ${\mu}g/mL$ 농도에서 대조군에 비해 유의적 증가를 보였다. $H_2O_2$로 유도한 산화적 스트레스 상황에서 감국 에탄올 추출물이 intracellular ROS 생성에 미치는 영향을 측정해본 결과, 30 ${\mu}g/mL$ 농도에서 antioxidant인 trolox 20 ${\mu}M$과 유사한 ROS 생성수준을 나타내어 유사한 항산화 효과를 보였으며, 그 이상의 농도에서는 더 높은 항산화 효과를 나타냈다. $H_2O_2$로 유도한 산화적 스트레스 상황에서 조골세포의 collagen 및 ALP의 합성을 억제하고 파골세포로의 분화 증강과 골흡수를 촉진시키는 것으로 알려진 TNF-${\alpha}$ 생성정도를 측정한 결과, 감국 에탄올 추출물 처리에 의해 농도 의존적으로 생성이 감소되었으며, 200 ${\mu}g/mL$ 농도에서 대조군 대비 89% 수준을 나타내어 유의적 차이를 보였다. 이상의 결과를 통해 감국 에탄올 추출물은 $H_2O_2$로 유도된 산화적 스트레스 상황에서 세포 내 ROS 생성과 염증매개 cytokine인 TNF-${\alpha}$ 생성을 감소시킴으로써 조골세포 손상과 활성 감소를 억제하고, 증식과 분화를 촉진시키는 효과가 있는 것을 확인할 수 있었다. 따라서 감국 에탄올 추출물의 골다공증 예방을 위한 식물성 에스트로젠(phytoestrogen) 및 항산화 소재로의 이용 가능성이 있을 것으로 사료된다.

• 생명과학회지
• /
• 제20권5호
• /
• pp.760-767
• /
• 2010

지질, 단백질 및 DNA의 산화적 손상이 관절염, 간염, 위염, 대장염 및 치주 질환과 같은 만성 염증뿐만 아니라 암 전이에 관련되어 있다고 알려져 있다. 이러한 질환의 발생을 예방하기 위하여 독성이 없는 천연 화합물을 개발하는 것이 최근의 주요 연구 관심 대상이다. 산화적 스트레스와 관련 있는 DPPH radical, hydrogen peroxide, hydroxyl radical 및 과산화수소와 같은 활성산소에 대한 흑마늘(ABGE)의 소거능력이 연구되었다. 뿐만 아니라 TBARS assay를 이용하여 본 연구에서 사용된 산화방법으로 Fenton반응에 의하여 hydroxyl radical에 노출된 세포에서 ABGE의 항산화 효과도 조사되었다. ABGE는 활성산소종 중에서 특히 과산화수소에 대한 항산화 효능이 우수하였고 hydroxyl radical에 노출된 genomic DNA의 산화에 대한 보호 효과도 관찰되었다. 살아있는 세포에 대한 산화적 스트레스도 ABGE의 존재 하에서 억제되었다. 뿐만 아니라, 암전이와 관련 있는 MMP-2 및 MMP-9의 활성과 발현에 대한 ABGE의 효과를 gelatin zymography 및 western blot을 이용하여 조사하였다. ABGE는 PMA로 자극한 사람 섬유아육종세포로부터 분비된 MMP-2 및 MMP-9의 활성과 발현을 동시에 억제 하였으므로 암을 억제 할 수 있는 하나의 생리활성물질로 개발 될 수 있으리라 판단된다.

• Journal of Applied Biological Chemistry
• /
• 제59권4호
• /
• pp.305-311
• /
• 2016

본 연구는 야관문과 호로파 복합추출물인 YHM이 과산화수소($H_2O_2$)로 산화적스트레스를 가한 TM3 세포의 테스토스테론 발현에 미치는 영향을 확인하고자 수행되었다. 세포독성 시험을 수행하여 YHM의 경우 $40{\mu}g/mL$을 최고 농도로 중농도 $20{\mu}g/mL$, 저농도 $10{\mu}g/mL$ 처리군을 설정하였고, TM3 세포에 산화적 스트레스를 주기 위해서는, serum free 배지에 $50{\mu}M$의 과산화수소를 4시간 동안 처리하였다. 산화적 스트레스가 가해진 TM3 세포에 YHM 시료를 처리하여 세포 생존률에 미치는 영향을 평가하였을 때 모든 농도 처리군에서 세포증식이나 독성이 없었다. 테스토스테론은 과산화수소를 처리하였을 때 감소하였다가 YHM 시료를 처리하였을 때 control 수준으로 회복되거나, control 보다 더 증가하였다. 또한 시료에 의한 테스토스테론 양의 증가원인을 확인하기 위하여, 테스토스테론 합성 및 분해에 관여하는 효소들의 발현량을 ELISA와 Real-time PCR을 통해 알아보았다. 테스토스테론 합성에 관여하는 $3{\beta}$-HSD4와 17,20-desmorase는 과산화수소 처리 시 감소하였다가, YHM을 처리하였을 때는 control 수준으로 회복하였다. 테스토스테론을 estradiol 및 dihydrotestosterone로 변환시키는 aromatase와 $5{\alpha}$-reductase2는 과산화수소를 처리하였을 때 증가하였다가 YHM 시료를 처리하면 control 수준이나 그 이하로 감소하였다. 이 결과들로 보았을 때 YHM 시료는 TM3 세포의 증식에는 영향을 미치지 못 하지만, 산화적 스트레스에 의해 감소된 테스토스테론 합성 효소의 발현을 증가시키고, 반대로 증가되는 테스토스테론 분해 효소의 발현은 감소시켜, 결국 산화적 스트레스에 의해 저하된 테스토스테론의 양을 회복시키거나 증가시키는 효과가 있는 것으로 판단된다.

• Biomolecules & Therapeutics
• /
• 제13권3호
• /
• pp.150-155
• /
• 2005

The ethanolic extract of chestnut (Castanea crenata S. et Z., Fagaceae) inner shell (CISE) and one of its components, ellagic acid (EA), were evaluated for their protective effects against 1, 1-diphenyl-2-picryl hydrazine (DPPH) free radical generation and hydrogen peroxide-induced oxidative DNA damage in a mammalian cell line. CISE and EA were shown to possess the free radical scavenging effect against DPPH radical generation, significantly. They were also found to strongly inhibit hydrogen peroxide-induced DNA damage from Chinese hamster lung (CHL) cell, assessed by single cell gel electrophoresis assay and 8-hydroxy -2'-deoxy guanosine (8-OH-2'dG) assay. Furthermore, topical application of CISE [$12.5\%$(w/w) cream] and ellagic acid [$1.0\%$(w/w) cream] for 14 days potently inhibited malondialdehyde (MDA) formation of mouse dorsal skin (a marker of lipid peroxidation) induced by ultraviolet B exposure. Therefore, CISE and its component, ellagic acid, may be the useful natural antioxidants by scavenging free radicals, inhibition of lipid peroxidation and protecting oxidative DNA damage when topically applied.

• 한국수산과학회지
• /
• 제50권5호
• /
• pp.520-526
• /
• 2017

Carnosine was recently reported to protect against the DNA damage induced by oxidative stress. In this study, we investigated the protective effect of eel Anguilla japonica carnosine extracts prepared using different methods (heat treatment extracts, HTEs; ion exchange chromatography, IEC; ultrafiltration permeation, UFP) on leukocyte DNA damage using the comet assay. Human leukocytes were incubated with extracts of eel carnosine at concentrations (of 10, 50, $100{\mu}g/mL$), and then subjected to an oxidative stimulus [$200{\mu}M$ hydrogen peroxide ($H_2O_2$)]. Pretreatment of the cells for 30 min with carnosine significantly reduced the genotoxicity of $H_2O_2$ measured as DNA strand breaks. The protective effects of the three types of extract (HTE, IEC, and UFP) increased with concentration. At the highest concentration (100 g/mL). there were no statistical differences in oxidative damage between each extract treatment and PBS-treated negative controls. When leukocytes were incubated with carnosine for 30 min after exposure to $H_2O_2$. the protective ability of each extract changed. Therefore, eel carnosine inhibits the $H_2O_2$ induced damage to cellular DNA in human leukocytes, supporting the protective effect of this compound against oxidative damage.

• 한국응용약물학회:학술대회논문집
• /
• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
• /
• pp.67-67
• /
• 2003

Minocycline is known to protect neurons from microglia-mediated cell death in many experimental models of brain diseases including ischemic stroke, Huntingtons disease (HD), amyotrophic lateral sclerosis (ALS), traumatic brain injury, multiple sclerosis, and Parkinsons disease. When the activity of caspases was assessed using their fluorescent peptide substrates, activation of caspase-2, 3, 8, and 9 was evident within 2 8 hr following oxidative insult with 0.5 mM hydrogen peroxide in PC12 cells. Minocycline significantly attenuated activation of these caspases up to 18 hr, resulting a significant increase in the cell viability as assessed by MTT assay as well as trypan blue staining. However, cleavage of alpha-spectrin and a cdk5 activator p35, which are known to be substrates for calpain, remained unchanged in the presence of minocycline, suggesting that minocycline did not block caspase-3-independent cell death or necrosis. Moreover, co-treatment with minocycline and a calpain inhibitor calpeptin synergistically inhibited hydrogen peroxide-induced cell death. These data suggest that minocycline directly inhibited apoptosis, but not necrosis, after oxidative insult in PC12 cells.