• Proceedings of the Botanical Society of Korea Conference
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• 2002.04a
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• pp.94-94
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• 2002

• BMB Reports
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• v.34 no.3
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• pp.278-283
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• 2001

Antioxidant and redox enzyme activities are known to be involved in the cellular responses to various stresses. Their variations were observed according to the growth cycle of the fission yeast Schizosaccharomyces pombe. Peroxidase activity appeared to be notably higher in the early exponential phase than in the mid-exponential and stationary phases. However, catalase activity showed a variation pattern resembling the growth curve. Glutathione S-transferase activity was higher in the early exponential and late stationary phases. Activities of the two redox enzymes, thioredoxin and thioltransferase (glutaredoxin), were high in the stationary phase. However, their activities appeared to increase from the early exponential to mid-exponential phase. Total glutathione content had a varying pattern similar to that of thioredoxin and thioltransferase. However, its content in the early exponential phase was high. These results propose that antioxidant and redox enzymes tested are also involved in the mechanism of cell growth.

• Fisheries and Aquatic Sciences
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• v.23 no.8
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• pp.23.1-23.10
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• 2020

This study was conducted to evaluate the acute effects of waterborne cadmium exposure on bioaccumulation and antioxidant enzymes in eels (Anguilla japonica) and to determine the median lethal concentration (LC₅₀). Fish were exposed to different cadmium concentrations (0, 0.15, 0.30, 0.61, 1.83, 3.08, 3.67, 4.29, and 5.51 mg L^-1) for 96 h. The LC₅₀ of A. japonica to cadmium was 3.61 mg L^-1. Cadmium accumulation generally increased in tissues with increasing waterborne cadmium concentrations. At ≥ 1.83 mg L^-1 exposure, all tissues accumulated significant cadmium concentrations compared with the control group, in the order of kidney > liver > gill > spleen > muscle. Measurements of variation in actual cadmium concentrations showed that a reduction of the metal in experimental water was related to cadmium accumulation in tissues. As activity alteration of antioxidant enzymes for reactive oxygen species, superoxide dismutase and catalase activities increased at ≥ 0.61 mg L^-1 significantly, glutathione peroxidase and glutathione S-transferase activities were not significantly changed. The results of this study suggest that acute exposure to waterborne cadmium is potentially fatal to A. japonica due to the metal's major accumulation in various tissues and the effect of antioxidant enzyme activity.

• Plant Biotechnology Reports
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• v.2 no.2
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• pp.113-122
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• 2008

Nitric oxide (NO) affects the growth and development of plants and also affects plant responses to various stresses. Because NO induces root differentiation, we examined whether or not it is involved in increased ROS generation. Treatments with sodium nitroprusside (SNP), an NO donor, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), a specific NO scavenger, and $N{\omega}-nitro-{\text\tiny{L}}-arginine$ methyl ester hydrochloride (${\text\tiny{L}}-NAME$), an NO synthase (NOS) inhibitor, revealed that NO is involved in the adventitious root growth of mountain ginseng. Supply of an NO donor, SNP, activates NADPH oxidase activity, resulting in increased generation of $O_2{^{{\cdot}-}}$, which subsequently induces growth of adventitious roots. Moreover, treatment with diphenyliodonium chloride (DPI), an NADPH oxidase inhibitor, individually or with SNP, inhibited root growth, NADPH oxidase activity, and $O_2{^{{\cdot}-}}$ anion generation. Supply of the NO donor, SNP, did not induce any notable isoforms of enzymes; it did, however, increase the activity of pre-existing bands of NADPH oxidase, superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, and glutathione reductase. Enhanced activity of antioxidant enzymes induced by SNP supply seems to be responsible for a low level of $H_2O_2$ in the adventitious roots of mountain ginseng. It was therefore concluded that NO-induced generation of $O_2{^{{\cdot}-}}$ by NADPH oxidase seems to have a role in adventitious root growth of mountain ginseng. The possible mechanism of NO involvement in $O_2{^{{\cdot}-}}$ generation through NADPH oxidase and subsequent root growth is discussed.

• Journal of Nutrition and Health
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• v.32 no.1
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• pp.17-23
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• 1999

The purpose of this study was to determine the extent of oxidative stress in NIDDM patients with diabetic complications and to determine the relationship between oxidative stress and diabetic complications. For this study, 139 NIDDM patients were recruited, 85 with diabetic complications and 54 without complications were recruited. The concentration of malondialdehyde(MDA) and the activities of antioxidant enzymes including catalase, superoxide dismutase(SOD), gluthatione peroxidase(GSH-Px)were determined. The daily intakes and plasma concentrations of beta-carotene, lycopene, lutein nd alpha-tocopherol were determined by food frequency questionnaire and by high performance liquid chromatography(HPLC), respectively. Among the antioxidant enzymes studied, only GSH-Px activity was lower in NIDDM patient, with diabetic complications than in those without complications(2.91$\pm$0.80 vs 3.54$\pm$0.44 U/mgHb, p<0.05). Those NIDDM patients with diabetic complications had higher MDA concentrations than those without diabetic complications(1.40$\pm$0.25 vs 1.25$\pm$0.11 nmol/ml, p<0.05). There were no significant differences in the dietary intakes of total carotenoids(2854 vs 2824ug/day)or vitamin E (9.5$\pm$3.2 vs 9.5$\pm$2.0mg/day)between NIDDA patients with and without complications. However, the plasma concentrations of beta-carotene and lycopene were significantly lower in NIDDM patients with complications than in NIDDM patients without complications (Beta-carotene : 24.2$\pm$12.5 vs 33.1$\pm$16.2(ug/dl), lycopene : 2.8$\pm$2.1 vs 4.3$\pm$2.8(ug/dl)). This study showed that in NIDDM patients with complications, the lipid peroxidation of erythrocytes was higher increased and the antioxidant reserves were significantly dipleted, compared with NIDDM patients without complications. The lower plasma concentrations of beta-carotene and lycopene in NIDDM patients may be due to the presence of diabetic complication, not due to the lower dietary intakes of antioxidant vitamins. To define the role of carotenoids in diabetes, more experimental and clinical studies are needed.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.5
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• pp.608-611
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• 2004

The 15 buffaloes were divided into three groups, viz. group 1: normal cyclic buffaloes; group 2: postpartum anoestrus buffaloes and group 3: post partum anoestrus buffaloes supplemented with intramuscular injections of Vit. E.-care Se containing 500 mg $\alpha$-tocopheryl acetate and 15 mg selenium at weekly intervals for two months. The postpartum anoestrus buffaloes had significantly higher levels of erythrocytic lipid peroxidation, superoxide dismutase and glucose-6 phosphate dehydrogenase activities but lower glutathione peroxidase activity as compared to normal cyclic buffaloes. The supplementation of vitamin E and selenium lowered the level of erythrocytic lipid peroxidation, superoxide dismutase and glucose-6 phosphate dehydrogenase activities but it had no effect on whole blood selenium and erythrocytic gluathione peroxidase activity. All the animals in group 3 became cyclic and showed 60% conception rate.

• International Journal of Oral Biology
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• v.30 no.3
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• pp.77-84
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• 2005

EGCG[(-)-epigallocatechin gallate], is a major component of green tea has been considered as a major antioxidant constituent. It has been considered as potential chemopreventive and chemotherapeutic agents. However, very little is known about the cellular actions by which EGCG mediates its therapeutic effects. Various aspects of antioxidant activity of EGCG were evaluated in this study. EGCG itself did not show significant cytotoxicity. Significant 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was observed in all ranges of concentration ($0.8-100{\mu}g/ml$) used in this study. Protective effect of EGCG against hydrogen peroxide induced cell death was observed. Relatively high lipid peroxidation inhibitory activity were detected ($IC_{50}$ was about $20{\mu}g/ml$). EGCG also dose-dependently enhanced the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in V79-4 cells. In concentrations of $100{\mu}g/ml$ of EGCG, activities of SOD, CAT and GPX were measured as 36.9 U/mg of protein, 22.9 U/mg of protein and 17.8 U/mg of protein, respectively. When these values were compared with those of the control groups (24.9 U/mg of protein, 14.9 U/mg of protein and 11.7 U/mg of protein), the relative increases were calculated as 48, 54 and 52%, respectively. Taken together, our findings suggest that EGCG can act as an antioxidant by scavenging radicals and enhancing antioxidant enzyme activities.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2001.11b
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• pp.83-84
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• 2001

• Food Science and Industry
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• v.53 no.1
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• pp.43-55
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• 2020

Most reports demonstrated the substrate specificity-based kinetic properties of chitin or chitosan degrading enzymes. However, there is virtually less information on the high quality and quantity production of chitin or chitosan hydrolysates having a larger than (GlcN)₇ from the hydrolysis of high molecular weight chitosan using specific enzymes and their biological activity. Therefore, the production of such molecules and the discovery of such enzyme sources are very important. Fortunately, the author has established a mass production method of chitosan hydrolysates (GlcN)_n, n=2-13 that have been characterized as a potent antioxidant substance, as well as antifungal and antibacterial activities against Penicillium species and highly selective pathogenic bacteria. In addition, preclinical studies using (GlcN)_n, n=5-25 demonstrated that these molecules played a very important role in maintaining biometric balance. Collectively, it is implicated that the application of these mixed substances to foods with significant biological activity is very encouraging.

• YAKHAK HOEJI
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• v.48 no.1
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• pp.93-98
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• 2004

The purpose of this study was to evaluate the effect of pharbitidis seed extract (PE) on antioxidant enzymes. The cytotoxicities of PE were measured by 3- (4,5-dimethlthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay; The change of superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activity assay were measured. The SOD activities by PE-treated groups were lower than control group's one. In the co-treated with hydrogen peroxide ($H_2O$$_2$) group, SOD activity was higher than $H_2O$$_2$ treated group's activity In the case of GPx, GPx activities were increased in both PE-treated and co-treated with $H_2O$$_2$ group. In the case of CAT $H_2O$$_2$ treated group's activityies were very increased. The CAT activities by PE-treated groups were lower than control group's one, but the activity of co-treated group with H $_2$O$_2$ was higher than that of control group's one. These results suggest that PE has antioxidant activity.