• BMB Reports
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• v.38 no.5
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• pp.609-618
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• 2005

$\gamma$-Glutamyl transpeptidase (GGT, EC 2.3.2.2.) catalyzes the transfer of the $\gamma$-glutamyl moiety from $\gamma$-glutamyl containing ompounds, notably glutathione (GSH), to acceptor amino acids and peptides. A second gene (GGTII) encoding GGT was previously isolated and characterized from the fission yeast Schizosaccharomyces pombe. In the present work, the GGTII-lacZ fusion gene was constructed and used to study the transcriptional regulation of the S. pombe GGTII gene. The synthesis of $\beta$-galactosidase from the GGTII-lacZ fusion gene was significantly enhanced by NO-generating SNP and hydrogen peroxide in the wild type yeast cells. The GGTII mRNA level was increased in the wild-type S. pombe cells treated with SNP. However, the induction by SNP was abolished in the Pap1-negative S. pombe cells, implying that the induction by SNP of GGTII is mediated by Pap1. Fermentable carbon sources, such as glucose (at low concentrations), lactose and sucrose, as a sole carbon source, enhanced the synthesis of $\beta$-galactosidase from the GGTII-lacZ fusion gene in wild type KP1 cells but not in Pap1-negative cells. Glycerol, a non-fermentable carbon source, was also able to induce the synthesis of $\beta$-galactosidase from the fusion gene, but other non-fermentable carbon sources such as acetate and ethanol were not. Transcriptional induction of the GGTII gene by fermentable carbon sources was also confirmed by increased GGTII mRNA levels in the yeast cells grown with them. Nitrogen starvation was also able to induce the synthesis of $\beta$-galactosidase from the GGTII-lacZ fusion gene in a Pap1-dependent manner. On the basis of the results, it is concluded that the S. pombe GGTII gene is regulated by oxidative and metabolic stress.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.5
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• pp.419-430
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• 1987

The damage of plasmid DNA by lipid peroxidation and its inhibition were investigated through the model system of DNA and linoleic acid at $37^{\circ}C$. The degree of DNA damage increased in proportion to the increase of concentration and peroxidation of linoleic acid. DNA damage induced from linoleic acid peroxidation was greatly inhibited by the addition of active oxygen scavengers, especially, singlet of oxygen scavenge$(\alpha-tocopherol,\;cysteine)$ and superoxide anion scavenger(superoxide dismutase, ascorbic acid) in reaction system. These active oxygens, such as superoxide anion and hydrogen peroxide were rapidly generated in the early stage of peroxidation (POV below 100 mg/kg) and also scanvenged by the addition of superoxide dismutase and catalase, respectively. Hydroperoxide isolated from autoxidised linoleic acid showed DNA damage. Hydroperoxide induced-DNA damage was not inhibited by active oxygen scavengers. Lipid oxidation products, malonaldehyde and hexanal, also influenced on the DNA damage. Accordingly, it is speculated that DNA damage by lipid oxidation products is due to active oxygens such as singlet oxygen and superoxide anion formed in the early stage of peroxidation, direct action of hydroperoxide and formation of low molecular carbonyl compound-DNA complex. Furthermore, DNA damage induced by lipid peroxidation was remarkably inhibited by the addition of active oxygen scavengers and natural antioxidative fractions extracted from garlic and ginger. These antioxidative fractions also suppressed the generation of active orygens and linoleic acid oxidation. It is assumed that the inhibition of DNA damage by garlic and ginger extracts is due to the scavenging effect of active oxygens and the inhibition of hydroperoxide and oxidation products formation.

• Journal of Oriental Neuropsychiatry
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• v.21 no.2
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• pp.125-140
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• 2010

Objectives : The purpose of this study is to examine from various angles the protective effect of Gastrodia elata Blume (GEB) against nerve cell death induced by $\beta$-amyloid by using the cell line SH-SY5Y, which is commonly utilized for toxicity testing in nerve cells, and to find out its mechanism of action. Methods : To begin with, as a result of assessing the rate of cell survival by employing MTT reduction assay, the treatment with $\beta$-amyloid at different concentrations caused cytotoxicity, which was inhibited by preprocessing GEB extract. In addition, after $\beta$-amyloid was processed with the cell SH-SY5Y, apoptosis progressed, which was reduced effectively by processing GEB extract. Results : When cytotoxicity was caused by using hydrogen peroxide, a representative ROS, in order to examine the antioxidant effect of GEB, its protective effect was also observed. Apart from ROS, reactive nitrogen species (RNS) are also known to play a crucial role in nerve cell death. The treatment with the NO donor SNAP increased the production of nitric oxide and the expression of iNOS, which was also inhibited by GEB extract. Meanwhile, as an attempt to find out the mechanism of action explaining the antioxidant effect, the intracellular antioxidant enzyme expressions were measured by RT-PCR, which showed that GEB extract increased the expressions of heme oxygenase-1, GAPDH and $\gamma$-glutamate cysteine ligase. Lastly, GEB extract had a protective effect against impaired memory induced by scopolamine in animal models (in vivo). Conclusions : These findings indicate that GEB has a protective effect against the death of cranial nerve cells, suggesting possibilities for the prevention and treatment of AD.

• Journal of Life Science
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• v.28 no.1
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• pp.83-89
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• 2018

This study was attempted to investigate the effects of Duchesnea chrysantha (DC) on antioxidative activities by in vivo. Rats were divided into four experimental groups which are composed of normal diet group (N group), high fat high cholesterol diet group (HF group), high fat high cholesterol diet with 5% DC powder supplemented group (DA group) and high fat high cholesterol diet with 10% DC powder supplemented group (DB group). Supplementation of DC powder groups resulted in increased activities of hepatic glutathione peroxidase and catalase. The microsomal superoxide radical contents of the DA and DB groups were significantly reduced compared to the high fat high cholesterol diet group. The mitochondrial superoxide radical contents of the DB group were significantly reduced compared to the high fat high cholesterol diet group. Hepatic hydrogen peroxide contents in cytosol were significantly reduced 5% and 10% DC powder supplemented group. The carbonyl values contents in mitochondria and microsome of the DA and DB groups were significantly reduced compared to the HF group. Thiobarbituric acid reaction substance (TBARS) values in liver were reduced in 10% DC powder supplemented group compared to the HF group. These results suggest that DC powder may have a strong regulatory effect in the activation of the antioxidative defense system.

• Journal of Life Science
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• v.30 no.8
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• pp.688-694
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• 2020

In a previous study, the total phenolic content in ethanol extracts of medicinal plants that naturally grow on Jeju Island were analyzed with the extracts of Raphiolepsis indica leaf found to have the highest. The current study was carried out to evaluate the total flavonoid content, radical-scavenging activity, and the protective effect of R. indica extracts and solvent fractions on oxidative stress in HaCaT keratinocytes. More specifically, total flavonoid content and 2-azino-bis 3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical-scavenging activity were measured to assess anti-oxidative activity, and protective effects against hydrogen peroxide (H₂O₂) were determined by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide assay on the HaCaT cells. Of the various fractions analyzed, the ethyl acetate extract of R. indica showed the highest total flavonoid content (149.13 mg/g extracts) and the lowest remaining ABTS. In addition, the ethyl acetate fraction was significantly more resistant against H₂O₂ than the negative control. Our results therefore suggest that an ethyl acetate fraction of R. indica protects HaCaT cells against oxidative stress and could prove useful for developing functional cosmetic materials.

• The Plant Pathology Journal
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• v.36 no.4
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• pp.335-345
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• 2020

Tomato grey mould has been one of the destructive fungal diseases during tomato production. Ten mM of menadione sodium bisulfite (MSB) was applied to tomato plants for eco-friendly control of the grey mould. MSB-reduced tomato grey mould in the 3rd true leaves was prolonged at least 7 days prior to the fungal inoculation of two inoculum densities (2 × 10⁴ and 2 × 10⁵ conidia/ml) of Botrytis cinerea. Protection efficacy was significantly higher in the leaves inoculated with the lower disease pressure of conidial suspension compared to the higher one. MSB-pretreatment was not effective to arrest oxalic acid-triggered necrosis on tomato leaves. Plant cell death and hydrogen peroxide accumulation were restricted in necrotic lesions of the B. cinereainoculated leaves by the MSB-pretreatment. Decreased conidia number and germ-tube elongation of B. cinerea were found at 10 h, and mycelial growth was also impeded at 24 h on the MSB-pretreated leaves. MSB-mediated disease suppressions were found in cotyledons and different positions (1st to 5th) of true leaves inoculated with the lower conidial suspension, but only 1st to 3rd true leaves showed decreases in lesion sizes by the higher inoculum density. Increasing MSB-pretreatment times more efficiently decreased the lesion size by the higher disease pressure. MSB led to inducible expressions of defence-related genes SlPR1a, SlPR1b, SlPIN2, SlACO1, SlChi3, and SlChi9 in tomato leaves prior to B. cinerea infection. These results suggest that MSB pretreatment can be a promising alternative to chemical fungicides for environment-friendly management of tomato grey mould.

• Applied Chemistry for Engineering
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• v.19 no.6
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• pp.674-679
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• 2008

$TiO_2$ impregnated stainless steel fiber photocatalysts ($TiO_2/SSF$) were fabricated to overcome inherent problems of powdery $TiO_2$ photocatalysts in water treatment. Adhesion strength of the impregnated $TiO_2$ was examined using an ultrasonic-cleaner. Photocatalytic activity was evaluated through decomposition experiment of methylene blue and formic acid. Bactericidal efficiency was evaluated through sterilization experiment of E. Coli and Vibrio Vulnificus. Adhesion strength of the impregnated $TiO_2$ was so high that more than 95% was left over even after the treatment in an ultrasonic-cleaner for 30 min. Methylene blue and formic acid were decomposed as much as 60% and 38% of the initial concentration and more than 99.9% of E. Coli and Vibrio Vulnificus were killed after 1 hour exposure to the prepared photocatalyst under UV irradiation. In the case of decomposition of formic acid, decomposition ratio increased if oxidants were added. Especially the decomposition ratio increased as high as 80% when hydrogen peroxide was added as an oxidant.

• Journal of Embryo Transfer
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• v.28 no.3
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• pp.193-198
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• 2013

This study was designed to evaluate the effect of L-cysteine on sperm characteristics and oocyte cleavage in vitro in Korean native cattle. For this study, the freezing of diluted semen were added with Triladyl containing 20% egg-yolk and/or 0, 5, 10 and 20 mM L-cysteine before cryopreservation. The viability in frozen-thawed sperm were estimated by SYBR14/PI double stain, acrosome damage with FITC-PNA, mitochondria intact with Rhodamin123 and hydrogen peroxide($H_2O_2$) level with carboxy-DCFDA by flow-cytometry. The developmental capacity was also assessed with cleavage rates in oocytes fertilized in vitro by frozen-thawed sperm. In results, the sperm viability was significantly increased in 10 mM and 20 mM concentrations of L-cysteine than other groups (p<0.05). In addition, acrosome damage was significantly decreased in 10 mM and 20 mM concentrations of L-cysteine than other groups (p<0.05). The mitochondria intact was also significantly increased in 10 mM and 20 mM concentrations of L-cysteine than other groups (p<0.05). On the other hand, the cleavage rates were significantly increased in 0 mM, 5 mM and 10 mM groups than 20 mM concentration of L-cysteine (p<0.05). The oocyte degeneration of oocytes were significantly decreased in 0 mM, 5 mM and 10 mM groups than in 20 mM L-cysteine group (P<0.05). However, there are no significantly differences among the L-cysteine treatment groups. We suggest that concentration of 10 mM L-cysteine have beneficial impact for sperm cryopreserved in Korean native cattle. This result also could be recommended for artificial insemination program if supported by an improvement in the fertility results and required further study.

• The Journal of Internal Korean Medicine
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• v.21 no.1
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• pp.13-22
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• 2000

목적 : 본(本) 연구(硏究)는 배기음(排氣飮)이 인간(人間)의 장관내(腸管內)에서 산화물(酸化物)에 의해 유발(誘發)된 세포(細胞)의 사망(死亡) 및 DNA의 손상(損傷)을 방지할수 있는지를 검증(檢證)하기 위한 실험(實驗)이다. 방법 : 배양(培養)된 인체장관(人體腸管) 세포계열(細胞系列)인 Caco-2 세포(細胞)에서 세포(細胞)의 사망(死亡)은 trypan bile의 소실정도에 의해서 평가했으며, DNA의 손상(損傷)은 double stranded DNA의 파괴정도를 측정하여 평가하였다. $H_2O_2$는 표본(標本) 산화제(酸化劑)로 사용되었다. 결과 : $H_2O_2$에 노출된 세포들의 세포사망(細胞死亡) 정도는 노출시간과 용량에 비례하여 증가하는 양상을 보였다. 배기음(排氣飮)은 $H_2O_2$에 의해 유발(誘發)되는 세포방지를 방지하였고, 0.05-1%의 농도범위에 걸쳐서는 그 효과가 용량에 비례하여 증가하는 양상을 보였다. $H_2O_2$에 의해 유발(誘發)된 세포손상(細胞損傷)은 catalase(hydrogen peroxide scavenger enzyme)와 deferoxamine(iron chelator)에 의해 억제되었다. 그러나 강력한 항산화제(抗酸化劑)인 DPPD는 $H_2O_2$에 의해 유발(誘發)되는 세포손상(細胞損傷)에는 영향을 주지 못했다. $H_2O_2$에 의해 유발(誘發)된 지질(脂質)의 과산화(過酸化)는 배기음(排氣飮)과 DPPD에 의해 억제되었다. $H_2O_2$에 의해 유발(誘發)된 DNA의 손상(損傷)은 배기음(排氣飮)에 의해 방지되었으며 용량에 의존하는 양상을 보였다. $H_2O_2$에 의해 유발(誘發)된 DNA의 손상은 catalase와 deferoxamine에 의해 억제되었지만 DPPD는 억제시키지 못했다. 배기음(排氣飮)은 $H_2O_2$에 의해 유발(誘發)된 ATP의 소실을 회복시켰다. 이러한 실험결과 $H_2O_2$에 의해 유발(誘發)된 세포(細胞)의 손상(損傷)은 지질(脂質)의 과산화(過酸化)와는 다른 독립적인 기전에 의해 일어남을 나타낸다. 결론 : 이러한 결과들로 볼 때 Caco-2 세포(細胞)에서 배기음(排氣飮)이 항산화작용(亢酸化作用)보다는 다른 기전을 통하여 Caco-2 세포안에서 산화제(酸化劑)에 의해 유발(誘發)된 세포(細胞)의 사망(死亡)와 DNA의 손상(損傷)을 방지할 수 있다는 것을 가리킨다. 따라서 본 연구(硏究)는 배기음(排氣飮)이 반응성산소기(反應性酸素基)에 의해 매개된 인체(人體) 위장관질환(胃腸管疾患)의 치료(治療)에 사용할 수 있을 가능성(可能性)이 있음을 제시하고 있다.

• Journal of environmental and Sanitary engineering
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• v.7 no.2
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• pp.95-110
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• 1992

Much progress has been made in understanding the subcellular events of the human lung injuries after acute exposure to environmental air pollutants. Host of those events represent oxidative damages mediated by reactive oxygen species such as superoxide, hydrogen peroxide, and the hydroxy, free radical. Recently, nitric oxide (NO) was found to be endogenously produced by endothelial cells and cells of the reticulo-endothelial system as endothelialderived relaxation factor (EDRF) which is a vasoactive and neurotransmitter substance. Together with superoxide, NO can form another strong oxidant, peroxonitrite. The relative importance of exogenous sources of $N0/N0_2$ and endogenous production of NO by the EDRF producing enzymes in the oxidative stresses to the heman lung has to be elucidated. The exact events leading to chronic irreversible damage are still yet to be known. From chronic exposure to oxidant gases, progressive epithelial and interstitial damages develop. Type I epithelial cells become thicker and cover a smaller average alveolar surface area while thee II cells proliferate instead. Under acute damages, the extent of loss of the alveolar epithelial cell lining, especially type II cells appears to be a good predictor of the ensuing irreversible damage to alveolar compartment. Interstitial matrix undergo remodeling during chronic exposure with increased collagen fibers and interstitial fibroblasts. However, Inany of these changes can be reversed after cessation of exposure. Among chronic lung injuries, genetic damages and repair responses received particular attention in view of the known increased lung cancer risks from exposure to several air pollutants. Heavy metals from foundry emission, automobile traffics, and total suspended particulate, especially polycystic aromatic hydrocarbons have been positively linked with the development of lung cancer. Asbestos in another air pollutant with known risk of lung cancer and mesothelioma, but asbestos fibers are nonauthentic in most bioassays. Studies using the electron spin resonance spin trapping method show that the presence of iron in asbestos accelerates the production of the hydroxy, radical in vitro. Interactions of these reactive oxygen species with particular cellular components and disruption of cell defense mechanisms still await further studies to elucidate the carcinogenic potential of asbestos fibers of different size and chemical composition. The distribution of inhaled pollutants and the magnitude of their eventual effects on the respiratory tract are determined by pollutant-independent physical factors such as anatomy of the respiratory tract and level and pattern of breathing, as well as by pollutant-specific phyco-chemical factors such as the reactivity, solubility, and diffusivity of the foreign gas in mucus, blood and tissue. Many of these individual factors determining dose can be quantified in vitro. However, mathematical models based on these factors should be validated for its integrity by using data from intact human lungs.