• 한국초지조사료학회지
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• 제33권3호
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• pp.159-166
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• 2013

We have previously investigated the proteome changes of rice leaves under heat stress (Lee et al. in Proteomics 2007a, 7:3369-3383), wherein a group of antioxidant proteins and heat shock proteins (HSPs) were found to be regulated differently. The present study focuses on the biochemical changes and gene expression profiles of heat shock protein and antioxidant genes in rice leaves in response to heat stress ($42^{\circ}C$) during a wide range of exposure times. The results show that hydrogen peroxide and proline contents increased significantly, suggesting an oxidative burst and osmotic imbalance under heat stress. The mRNA levels of chaperone 60, HSP70, HSP100, chloroplastic HSP26, and mitochondrial small HSP responded rapidly and showed maximum expression after 0.5 or 2 h under heat stress. Transcript levels of ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and Cu-Zn superoxide dismutase (Cu-Zn SOD) showed a rapid and marked accumulation upon heat stress. While prolonged exposure to heat stress resulted in increased transcript levels of monodehydroascorbate reductase, peroxidase, glyoxalase 1, glutathione reductase, thioredoxin peroxidase, 2-Cysteine peroxiredoxin, and nucleoside diphosphate kinase 1, while the transcription of catalase was suppressed. Consistent with their changes in gene expression, the enzyme activities of APX and DHAR also increased significantly following exposure to heat stress. These results suggest that oxidative stress is usually caused by heat stress, and plants apply complex HSP- and antioxidant-mediated defense mechanisms to cope with heat stress.

• Journal of Applied Biological Chemistry
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• 제44권4호
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• pp.159-162
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• 2001

Plant stress incurred by flooding was studied in terms of oxidative stress, using greened rice seedlings subjected to a complete submergence followed by re-exposure to air under illumination ($30W/m^2$). It appeared that shoot tissues of the seedlings suffered oxygen deficiency during the flooding treatment, pertinent to the general concept. Interestingly enough, however, membrane peroxidation in shoots was enhanced by the submergence, as assessed by the content of 2-thiobarbituric acid-reactive substances (TBARS), and the re-aeration resulted in a rapid reduction of TBARS content. Such pattern of response was also seen in the change in the steady state level of $H_2O_2$. In contrast, superoxide dismutase and glutathione reductase that are involved in the detoxifying processes of superoxide in plant cells were significantly activated only during the re-aeration. These results allowed us to suggest the followings as a working hypothesis. Photorespiration-linked production of $H_2O_2$ may largely contribute to the increase in $H_2O_2$ level as well as TBARS production in shoots during the submergence. An abrupt re-supply of $CO_2$ by the re-aeration brings the photosynthetic apparatus back to full operation, suppressing photorespiration and probably causing a momentary, excess formation of superoxide and its dismutation product through side reaction, which gives rise to activating substrate-inducible antioxidative enzymes.

• 한국식품영양과학회:학술대회논문집
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• 한국식품영양과학회 2004년도 Annual Meeting and International Symposium
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• pp.150-157
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• 2004

Cruciferous vegetables are rich in organosulfur compounds such as isothiocyanates and sulfides. While the isothiocyanates, corresponding to pungent principle, are generated from myrosinase-catalyzed hydrolysis of glucosinolates, the sulfides can be generated non-enzymatically. Recent studies provide evidences that some sulfur compounds in these vegetables show a chemopreventive action against carcinogenesis; while isothiocyanates such as sulforaphane induce phase 2 enzymes (glutathione S-transferase/quinone reductase), disulfides tends to elevate the level of phase 1 and 2 enzymes. Especially, sulforaphane rich in Cruciferae vegetables has been reported to express anticarcinogenic effect in some organs such as liver, kidney or intestine. When the level of sulfur compounds in Cruciferous and Alliaceous vegetables was determined by GC/MS (SIM), the richest in sulforaphane is broccoli followed by turnip, cabbage, radish, kale, cauliflower and Chinese cabbage. Meanwhile, the sulfides are predominant in Alliaceous vegetables such as onion. In related study, the administration of vegetable extract elevated the GST level by 1.5 fold for broccoli, 1.4 fold for radish, and 1.3 for onion. Thus, the vegetables frequently used in Korean dish contain relatively high amount of anticarcinogenic sulfur compounds. Moreover, the combination of broccoli and radish extracts elevated the GST induction up to 1.84 folds of control. In addition, the Kakdugi, fermented radish Kimchi was observed to show a comparable GST induction despite the decomposition of methylthio-3-butenylisothiocyanate (MTBI). Therefore, the combination of vegetables including broccoli, and fermented radish Kimchi would be useful as a functional food for chemoprevention.

• Food Science and Biotechnology
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• 제16권3호
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• pp.404-408
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• 2007

In this study, we investigated the effects by age of long-tenn supplementation of Epimedium koreanum Nakai (EKN)-containing water on the in vivo antioxidant capacities of rats. All rats were reared in a conventional system, and none of the rats showed any signs of aversion to the EKN solution. Neither the mean nor maximum life spans of the rats were extended by long-tenn administration of the solution. The EKN extract caused decreases in the levels of serum thiobarbituric acid reactive substances in the rats. The activities of superoxide dismutase, catalase, and glutathione (GSH) peroxidase within the liver cytosol decreased with age in both the control and EKN-supplemented groups. GSH peroxidase activity, however, was higher at old age in the EKN-supplemented group. The activities of GSH reductase and GSH-S-transferase, and the levels of free-sulfhydryl (SH) and total-SH group gradually decreased with age in both groups. However, there was some tendency for higher levels in the EKN supplemented group at a corresponding age. These results indicate that long-tenn supplementation of EKN water extracts alone does not exhibit discernible adverse effects in rats, and has some enhancing effects on the antioxidant capacities of the blood and liver, but it does not have life-prolonging effects.

• 대한의생명과학회지
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• 제21권2호
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• pp.60-68
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• 2015

NecroX-7 is a novel small compound of the NecroX series based on the indole moiety, which has potent cytoprotective and antioxidant properties. We previously detected potential immune regulatory effects of NecroX-7 in immune related diseases like Graft-versus-Host Disease. However, the function and the underlying mechanisms of immunological effects of NecroX-7 in the immune system have not been well established. In this study, we investigated the immune response characterization of differentially expressed genes of NecroX-7 administration in $CD4^+$ T cells by microarray analysis. $CD4^+$ T cells stimulated with NecroX-7 ($40{\mu}M$) or vehicle for 72 hours resulted in the identification of 337 differentially expressed genes (1.5 fold, P<0.05) by expression profiling analysis. Twenty eight of the explored NecroX-7-regulated genes were related to immune system processes. These genes were validated by quantitative real-time PCR. The most significant genes were glutathione reductase, eukaryotic translation elongation factor 1, lymphotoxin-alpha, heat shock protein 9 and chloride intracellular channel protein 4. These findings demonstrate the strongly immune response of NecroX-7 in $CD4^+$ T cells, suggesting that cytoprotection and immune regulation may underlie the critical aspects of NecroX-7 exposure.

• Journal of Nutrition and Health
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• 제36권3호
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• pp.245-254
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• 2003

The aim of this study was to investigate the effects of P/S ratio of fatty acid and antioxidant (vitamin E, selenium) supplements on the serum lipid levels and hepatic antioxidant enzyme activity in rats. Female 16-week-old Sprague-Dawley rats were fed 6 different experimental diets for 4 weeks. While the peroxidizability index (PI) levels of fatty acids in the experimental diets were fixed at 81.22, the levels of P/S ratio of fatty acids were formulated at 0.38, 1.00, 4.81 (LP, MP, HP). These diets were supplemented with vitamin E (1,000 mg/kg diet) and selenium (2.5 mg/kg diet) (LP-S, MP-S, HP-S). This study showed that the serum concentrations of total-cholesterol and HDL-C increased with the increasing of the P/S ratio in the diet (p <0.05). Antioxidant supplementation significantly lowered the concentrations of triglyceride (TG) and VLDL-C of serum (p<0.05). Levels of thiobarbituric acid reactive substance (TBARS) in the liver tended to decrease with the increasing of the P/S ratio in the diet (p<0.001), but antioxidant enzyme activity in the liver was not significantly different. In addition, antioxidant supplementation significantly lowered TBARS level in the liver (p<0.05), but had no effect on antioxidant enzyme activity except for glutathione reductase (p<0.05). In conclusion, it is necessary to consider the properties of dietary fatty acids and antioxidants supplementation for the prevention of cardiovascular diseases.

• Journal of Nutrition and Health
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• 제10권4호
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• pp.24-32
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• 1977

It was attempted in this study to assess the vitamin $B_{1},\;B_{2}$, and $B_6$ status in tissue by determination of erythrocyte transketolase (TK), glutathione reductase (GR), and aspartate aminotransferase (AST) activities, and their activation by their respective coenzymes, thiamine pyrophosphate, flavin-adenine dinucleotide, and pyridoxal-5-phosphate. The activities of erythrocyte enzymes were stable for more than 30 days when erythrocyte had been stored at $-20^{\circ}C$ and affirmed that the enzyme activities were more stable in the case of deep frozen sotrage of erythrocytes rather than hemolysates. The assay procedures involving ultraviolet kinetic analysis with continuous monitoring for each of enzymes have good within-batch and between-batch precisions and will be avalable in the routine laboratories for the nutritional and clinical surveys. Activity coefficient of TK, GR, and AST was studied in healthy medical students (fifteen men and twelve women, between 21 and 30 years old) on an unrestricted diet. The mean activity coefficient of TK, GR, and AST were 1.18, 1.35, and 2.01 for men, and 1.14, 1.33, and 1.83 for women, respectively. And the upper limit of normal (mean+2SD) were 1.52, 1.69, and 2.61 for men, and 1.50, 1.61, and 2.37 for women, respectively.

• Journal of Nutrition and Health
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• 제29권9호
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• pp.1003-1012
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• 1996

We examined the relationship among riboflavin intake, work activity, erythrocyte glutathione reductase activity coefficient(EGR AC)and urinary riboflavin excretion. We also attempted to determine factors affecting seasonal riboflavin status of rural women. All information about nutrient intake, work activity and riboflavin biochemical status was repeatly collected in three seasons ; farming season(June), harvest season(October), nonfarming season(February). EGR AC was negatively correlated with riboflavin intake(P<0.005) and positively correlated with the duration(min) of farming activity(P<0.005) and the percentage of lean body mass(LBM) (%) representing long term physical activity(P<0.05) in harvestseason. Urinary riboflavin excretion was positively correlated with the ratio of riboflavin intake to 1,000kcal of energy expenditure (P<0.05) in farming season and negatively correlated with the duration(min) of farming activity (P<0.05) and crude nitrogen balance(P<0.005) in harvest season. It appeared that EGR AC seems to increase and urinary riboflavin excretion seems to decrease as work activity increase. Therefore work activity would be expected to deteriorate riboflavin status. Multiple regression analysis of variables showed that in general EGR AC was affected by riboflavin and energy intakes, energy expenditure, energy balance, the duration(min) of farming activity, LBM (%). Urinary riboflavin excretion was affected by riboflavin and protein intakes, LBM(kg) and crude nitrogen balance. Crude nitrogen balance affected urinary riboflavin excretion in all seasons. The result indicated that work activity as well as nutrient intake seemed to affect riboflavin status, especially EGR AC was affected preferentially be work activity in all seasons.

• Journal of Nutrition and Health
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• 제33권1호
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• pp.23-32
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• 2000

The purpose of this study was to investigate the effcts of n-3, n-6 fatty arid and d-limonene on histopathological and biochemical changes in experimental rat hepatocarcinogenesis. To attain the above objectives, weanling Sprague-Dawley female rats were intraperitoneally injected twice with a dose of diethylnitrosamine(DEN, 50mg/kg body weight) and after 1 week 0.05% phenobarbital was provided with water. Sardine oil rich in n-3 fatty acids and corn oil rich in n-6 fatty acids were fed at 15% by weight and 5% d-limonene was added to the diet in each group. Ten weeks or 20 weeks after DEN treatment, rats were sacrifirced. The formation of glutathione S-transferase placental form positive(GST-P$\^$+/) foci was significantly decreased by the treatment of either sardine oil or d-limonene HMG-CoA reductase activity was not affected by dietary oils and d-limonene. Protein kinase C (PKC) activity was decreased by either sardine oil or d-limonene. Particularly d-limonene decreased the membrane PKC activity. Membrane Cholesterol/Phospholipid(Chol/PL) ratio was significantly decreased by d-limonene in sardine oil group. The data showed that GST-P$\^$+/ foci number was positively correlated with membrane PKC activity and serum cholesterol and negatively correlated with liver cholesterol level. These results suggest informations about the correlation between histopathological and biochemical changes such as cholesterol metabolism and PKC activity in experimental hepatocarcinogenesis and thereby can elucidate the possible mechanism related to the cancer inhibition.(Korean J Nutrition 33(1) : 23-32, 2000)

• Mycobiology
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• 제38권4호
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• pp.302-309
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• 2010

Formic acid is a representative carboxylic acid that inhibits bacterial cell growth, and thus it is generally considered to constitute an obstacle to the reuse of renewable biomass. In this study, Saccharomyces cerevisiae was used to elucidate changes in protein levels in response to formic acid. Fifty-seven differentially expressed proteins in response to formic acid toxicity in S. cerevisiae were identified by 1D-PAGE and nano-liquid chromatography-tandem mass spectrometry (nano-LC-MS/MS) analyses. Among the 28 proteins increased in expression, four were involved in the MAP kinase signal transduction pathway and one in the oxidative stress-induced pathway. A dramatic increase was observed in the number of ion transporters related to maintenance of acid-base balance. Regarding the 29 proteins decreased in expression, they were found to participate in transcription during cell division. Heat shock protein 70, glutathione reductase, and cytochrome c oxidase were measured by LC-MS/MS analysis. Taken together, the inhibitory action of formic acid on S. cerevisiae cells might disrupt the acidbase balance across the cell membrane and generate oxidative stress, leading to repressed cell division and death. S. cerevisiae also induced expression of ion transporters, which may be required to maintain the acid-base balance when yeast cells are exposed to high concentrations of formic acid in growth medium.