• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1597-1600
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• 2006

The mononuclear iron complex 1, $Fe^{III}$(Hbida)Cl($H_2O$), was synthesized using a tripodal tetradentate ligand, N-(benzimidazol-2-ylmethyl)iminodiacetic acid (H3bida), which has two carboxylate groups, one benzimida- zoyl group, and one tertiary amine where it serves as a tetradentate chelating ligand for the octahedral Fe(III) ion. The four equatorial positions of the octahedral complex are occupied by two monodentate carboxylates, a benzimidazole nitrogen, and an oxygen of a water molecule. One of the axial positions is occupied by an apical nitrogen of the Hbida and the other by a chloride anion. The mononuclear octahedral complex 1 mimics the geometry of the key intermediate structure of the catalytic reaction cycle proposed for the FeSODs, which is a distorted octahedral geometry with three histidyl imidazoles, an aspartyl carboxylate, a superoxide anion, and a water molecule. The redox potential of complex 1, $E_{1/2}$ is -0.11V vs. Ag/AgCl (0.12 V vs. NHE), which is slightly lower than those reported for the most FeSODs. The magnetic susceptibility of complex 1 at room temperature is 5.83 $\mu$B which is close to that of the spin only value, 5.92 $\mu$B of high-spin d5 Fe(III).

• Journal of Oriental Neuropsychiatry
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• v.8 no.2
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• pp.39-50
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• 1997

This experiment was to investigate the antioxidant effect of Sesimtang(SST) on brain tissues of mouse. The experimental groups were divided into three groups and treated ad follows for 15 days ; Normal group(NC), Vt.E admistrated group(PC), SST administrated Group(SST). After the extracting microsome from brain of mouse, those were measured the amounts of oxidant materials like MDA(malonaldehyde) and $H_2O_2$, then activities of antioxidant enzymes like SOD(superoxide dismutase), catalase, NADPH-cytochrome P-450 reductase. The results were as follows; 1. In TBA reaction to measure the amount of MDA, oxidant material of brain tissue of aged rat, both treated groups showed significant decrease. 2. Hydrogen peroxide formation was showed significant decrease in both treated groups than normal group. 3. Superoxide dismutase activity was increased in both treated groups than normal group, and showed little change in SST administrated group than normal group. 4. Catalase activity was increased in both treated groups than normal group. 5. NADPH-cytochrome P-450 reductase activity was increased in both treated groups than normal group.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2271-2278
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• 2007

Electron transfer of a redox protein at a bare gold electrode is too slow to observe the redox peaks. A novel Nafion-riboflavin functional membrane was constructed during this study and electron transfer of cytochrome c, superoxide dismutase, and hemoglobin were carried out on the functional membrane-modified gold electrode with good stability and repeatability. The immobilized protein-modified electrodes showed quasireversible electrochemical redox behaviors with formal potentials of 0.150, 0.175, and 0.202 V versus Ag/AgCl for the cytochrome c, superoxide dismutase and hemoglobin, respectively. Whole experiment was carried out in the 50 mM MOPS buffer solution with pH 6.0 at 25 oC. For the immobilized protein, the cathodic transfer coefficients were 0.67, 0.68 and 0.67 and electron transfer-rate constants were evaluated to be 2.25, 2.23 and 2.5 s?1, respectively. Hydrogen peroxide concentration was measured by the peroxidase activity of hemoglobin and our experiment revealed that the enzyme was fully functional while immobilized on the Nafion-riboflavin membrane.

• The Korean Journal of Ecology
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• v.25 no.6
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• pp.371-377
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• 2002

Leaves of two-week old seedlings of tomato (Lycopersicon esculentum) were treated with various concentrations (0, 0.2 and 0.4 $\mu$g/1) of 2,4,5-trichlorobiphenyl (PCB-29) and subsequent growth of seedlings, symptoms of oxidative stress and activities of antioxidant enzymes were investigated. Compared with the non-treated control, foliar application of PCB-29 decreased both biomass and superoxide ($O_2$) radical production but increased hydrogen peroxide production and lipid peroxidation such as malondialdehyde (MDA) formation with increased activities of superoxide dismutase (SOD), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX). Further studies on the isozymes of SOD, peroxidase (POD) and APX showed that all three isozymes of SOD such as Mn-SOD, Fe-SOD and Cu/Zn-SOD, two among four isozymes of POD and all three isozymes of APX were selectively increased in response to PCB. Therefore, we suggest that a possible cause for the reduction of seedling growth by PCB exposure is the oxidative stress including over production of hydrogen peroxide and the selective expression of specific isozymes of some antioxidant enzymes.

• The Korean Journal of Food And Nutrition
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• v.10 no.1
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• pp.37-43
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• 1997

This study was undertaken to evaluate as antioxidant activity against lipid peroxidation. Silymarin and silybin extracted from Silybum marianum were successively purified wit solvent fractionation by silica gel column chromatography. These isoflavonoid inhibited superoxide anion production in the xanthine oxidase system. In the rat liver microsomes, silymarin or silybin rapidly inhibited lipid peroxidation which was initiated enzymatically by reduced nicotinamide adenine dinucleotide phosphate(NADPH) or non-enzymatically by ascorbic acid or Fenton's reagent (H2O2+Fe2+). Mitochondrial lipid peroxidation was also inhibited by silymarin and silybin. silymarin and silybin inhibited on terminating radical chain reaction during lipid peroxidation in the enzymatic system of microsomes or in the linoleic acid hydroperoxide induced peroxidation system.

• Applied Biological Chemistry
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• v.41 no.4
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• pp.228-234
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• 1998

An adaptive measure of photosynthetic cells to a condition identified with a reduction of cellular energy charge, caused by water deficit-induced impairment of photosynthetic ATP production, was investigated using hydroponically cultured rice seedlings. Water stress treatment of the seedlings resulted in a marked decrease in cellular ATP level, a significant increase in the content of NAD(H) and concurrent decrease in that of NADP(H) in shoots, which accompanied a decrease in the activity of NAD kinase (EC 2.7.1.23) that specifically converts NAD(H) to NADP(H). The decline in the enzyme activity was particularly evident in the $Ca^{2+}/calmodulin-dependent$ kinase, the major form of NAD kinase in plants, whereas the level of active calmodulin remained unchanged during water deficit. The ratio of $NADP^+$ to NADPH was maintained nearly constant and no increases were seen in the level of $H_2O_2$ and the activities of $superoxide/H_2O_2-detoxifying$ enzymes in shoots stress-treated for two days. Based on these results, it may be suggested that rice plants take a strategy to cope with an adverse situation of limited photophosphorylation created by water deficit in that cells facilitate ATP production through glycolysis and oxidative phosphorylation; in doing so, rice cells suppress NAD kinase activity, consequently up-sizing the NAD(H) pool at the expense of the NADP(H) pool. Several parameters associated with the stress symptoms are also of implicative that there is no overproduction of superoxide radical or the related active oxygen at least in rice seedlings.

• The Journal of Korean Society for Radiation Therapy
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• v.9 no.1
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• pp.106-112
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• 1997

The present study was undertaken to investigate the effects of cultured MDCK cell line on the cell viability and the activities of superoxide dismutase(SOD). catalase, change of FOX 1 with low dose radiation. When MDCK cells were irradiated low dose (less than 50 cGy), the cell viability remains high after 2 hrs, but few changes after 24 hrs. In the low dose irradiated MDCK cells, the activities of SOD and catalase were increased with compared to control group and high dose. But the content of $H_2O_2$(FOX 1) was decreased. These results suggest that the cultured MDCK cells probably were induced expression of defense mechanism.

• ALGAE
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• v.21 no.1
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• pp.149-156
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• 2006

The aim of the present study was to evaluate the antioxidant activity of red algae in Jeju Island. The algal extracts were obtained with MeOH and fresh water at 20 and 70°C, and screened for antioxidant activities using hydroxyl radical (HO·), superoxide anion (O2–), hydrogen peroxide (H2O2) and DPPH free radical scavenging assays. Among them, Gracilaria verrucosa methanolic extract at 20°C (20ME, 96.85%), G. textorii aqueous extract at 20°C (20AE, 88.01%), Grateloupia filicina 20AE (85.35%), and Polysiphonia japonica 20ME (94.92%) exhibited the highest scavenging activities against HO·, O2–, H2O2, and DPPH free radicals, respectively. Moreover, P. japonica (20ME and 70ME) is correlated between DPPH free radical scavenging activity and polyphenolic contents. These results indicate that some red algae in Jeju Island could be potential candidates for development of antioxidants.

• The Journal of Internal Korean Medicine
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• v.28 no.1
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• pp.80-91
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• 2007

Objectives : Peroxynitrite (ONOO-), superoxide anion radical (?O2-) and nitric oxide (NO) are cytotoxic because they can oxidize several cellular components such as proteins, lipids and DNA. They have been implicated in the aging process, and age-related diseases such as Alzheimer's disease, rheumatoid arthritis, cancer and atherosclerosis. The aim of this study was to investigate Sabohwan's activity for scavenging ONOO- and its precursors. NO and ?02-. Methods : For this study, the fluorescent probes, namely 2',7'-dichlorodihydrofluorescein diacetate (DCFDA), 4.5-diaminofluorescein (DAF-2) and dihydrorhodamine 123 (DHR 123) were used. Results : Sabohwanblocked tert-butylhydroperoxide (t-BHP)-induced cell death in a dose-dependent fashion. It scavenged t-BHP-induced ONOO-, NO and ?O2- in YPEN cells. Sabohwan inhibited the generation of ONOO-, NO and ?O2- in the lipopolysaccharide (LPS)-treated mouse kidney postmitochondria both in vitro and in vivo. The lipid peroxide level increased and glutathione level decreased in the LPS-treated mice, whereas the ones in the Sabohwanadministered group among the LPS-treated mice reversed toward their natural levels. Conclusions : These results suggest that Sabohwanis an effective ONOO-, ?O2- and NO scavenger, and thereby it might have a potential role as a therapy against the aging process and age-related diseases.

• Preventive Nutrition and Food Science
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• v.19 no.3
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• pp.129-135
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• 2014

The protective role of phloroglucinol against oxidative stress and stress-induced premature senescence (SIPS) was investigated in vitro and in cell culture. Phloroglucinol had strong and concentration-dependent radical scavenging effects against nitric oxide (NO), superoxide anions ($O_2{^-}$), and hydroxyl radicals. In this study, free radical generators were used to induce oxidative stress in LLC-PK1 renal epithelial cells. Treatment with phloroglucinol attenuated the oxidative stress induced by peroxyl radicals, NO, $O_2{^-}$, and peroxynitrite. Phloroglucinol also increased cell viability and decreased lipid peroxidation in a concentration-dependent manner. WI-38 human diploid fibroblast cells were used to investigate the protective effect of phloroglucinol against hydrogen peroxide ($H_2O_2$)-induced SIPS. Phloroglucinol treatment attenuated $H_2O_2$-induced SIPS by increasing cell viability and inhibited lipid peroxidation, suggesting that treatment with phloroglucinol should delay the aging process. The present study supports the promising role of phloroglucinol as an antioxidative agent against free radical-induced oxidative stress and SIPS.