• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.732-736
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• 1999

The superoxide dismutase (SOD) in Lactococcus lactis was measured quantitatively and qualitatively under various culture conditions. The L. lactis SOD was induced by oxidative stress. As the concentration of paraquat to produce superoxide radicals increased, the growth of L. lactis decreased with concomitant increase of SOD activity. The SOD activity was found to be growth-phase dependent: when aerobically grown cells entered to the stationary phase, the activity increased gradually until the late stationary phase. From inhibition studies, L. lactis SOD was found to be insensitive to KCN and $H_2O_2$ which are known to inhibit Cu/ZnSOD and FeSOD, respectively. Moreover, as the concentration of manganese in the medium increased, the activity of SOD also increased. These data strongly suggested that L. lactis possessed a single manganese-containing SOD (MnSOD). Finally, a putative sod gene fragment of 510 bp was identified in L. lactis using a polymerase chain reaction (PCR) with degenerate primers designed from the deduced DNA sequences of known SOD genes.

• Archives of Pharmacal Research
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• v.28 no.1
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• pp.22-27
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• 2005

Bioassay-guided fractionation of methanol extract of Reynoutria sachalinensis flower using DPPH assay has led to the isolation of three anthraquinones and three flavonoids. Their structures were identified as emodin (1), emodin-8-O-$\beta$-D-glucopyranoside (2), physcion-8-O-$\beta$-D­glucopyranoside (3), quercetin-3-O-$\alpha$-L-arabinofuranoside (4), quercetin-3-O-$\beta$-D-galactopyra­noside (5), and quercetin-3-O-$\beta$-D-glucuronopyranoside (6) by comparing their physicochemical and spectral data with those published in literatures. All isolated compounds were evaluated for antioxidant activities with free radical 1, 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, superoxide radical scavenging and $Cu^{2+}$-mediated low density lipoprotein (LDL) oxidation assay. The results demonstrated that three flavonoids, 4, 5, and 6 had remarkable antioxidant activities with the $IC_{50}$ values of 64.3, 54.7, and 46.2${\mu}M$ (DPPH scavenging), the $IC_{50}$ values of 6.0, 6.7, and $4.4{\mu}M$ (superoxide radical scavenging) and the $IC_{50}$ values of 3.8, 3.2, and 5.4${\mu}M$ against LDL oxidation, respectively.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.230-234
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• 2007

Oxygen is required for many important aerobic cellular reactions, it may undergo electrontransfer reactions, which generate highly reactive membrane-toxic intermediates (reactive oxygen species, ROS), such as hydrogen peroxide, singlet oxygen, superoxide radical, hydroxyl radical, hydroperoxyl radical, hydroxy ion. Various mechanisms are available to protect cells against damage caused by oxidative free radicals, including scavenging enzyme systems such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). This antioxidant defense system is a very complex and finely tuned system consisting of enzymes capable of detoxifying oxygen radicals as well as low molecular weight antioxidants. In addition, repair and turnover processes help to minimize subcellular damage resulting from free radical attack. $H_2O_2$,one of the major ROS, is produced at a high rate as a product of normal aerobic metabolism. The primary cellular enzymatic defense systems against $H_2O_2$ are the glutathione redox cycle and catalase. From Northern blot analysis of total RNAs from cultured cell with $H_2O_2$ treatment, various results were obtained. Expression of Cu/Zn SOD decreased when cell passage increased, but the level of the Cu/Zn SOD was scarcely expressed in 35 passage.

• Archives of Pharmacal Research
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• v.27 no.2
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• pp.173-176
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• 2004

Three phenolic compounds, rosmarinic acid (1), methyl rosmarinate (2), ethyl rosmarinate (3), and two flavonoids, luteolin (4), luteolin-7-O-$\beta$-D-glucuronide methyl ester (5) were isolated from the aerial part of Lycopus lucidus (Labiatae). Their structures were determined by chemical and spectral analysis. Compounds 1-5 exhibited potent antioxidative activity on the NBT superoxide scavenging assay. The $IC_{50}$ values for compounds 1-5 were 2.59, 1.42, 0.78, 2.83, and 3.05 $\mu\textrm{g}$/mL respectively. In addition, five compounds were isolated from this plant for the first time.

• Food Science and Biotechnology
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• v.15 no.6
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• pp.993-996
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• 2006

Cyanidin 3-glucoside (C3G) isolated from black rice was investigated for hepatoprotective effects in HepG2 cells under oxidative stress. When an increase in the production of reactive oxygen species (ROS) was induced by gramoxone, cell viability was drastically decreased by 42%. However, in the presence of C3G, no hepatocytic damage was observed in HepG2 cells treated with gramoxone. C3G was found to manifest a stronger scavenging effect (91%) on superoxide anion radical ($O_2\;^{.-}$) than any of the other natural and synthetic antioxidants. Results suggest that C3G from black rice possesses hepatoprotective effects in vitro, which may be, at least in part, due to $O_2\;^{.-}$ scavenging.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.444-449
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• 2003

To investigate the long term effect of buchu (Chinese chives) diet on ROS formation in the liver and stin tissue of ICR mice, one of control, 2% or 5% buchu-added diet was fed to ICR mice for 12 months. Superoxide anion (O2ㆍ), hydrogen peroxide($H_2O$$_2$) and hydroxyl radical (ㆍOH) contents were measured in cytosol, microsome, mitochondria of liver and skin of mice, respectively. Behu diet showed a significant decrease of superoxide anion, hydrogen peroxide and hydroxyl radical contents in liver and skin tissues compared to control diet, and this effect is especially higer at 5% than at 2% buchu diet level. ICR mice showed an age-dependent increase in ROS contents, while the group fed buchu diet decreased its ROS contents significantly and ROS contents of liver appeared to be 2 fold higher than skin. The results of the present study suggest that antioxidative components and sulfur-compounds in buchu diet appear to be responsible for the inhibition of ROS formation in ICR mice.

• Journal of Life Science
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• v.21 no.5
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• pp.693-699
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• 2011

Spermidine is a ubiquitous polycation that is synthesized from putrescine, which serves as a precursor of spermine. In recent years, spermidine was found to be a polyamine that plays an important role in longevity. Reactive oxygen species (ROS) such as hydroxyl radical, superoxide and hydrogen peroxide have been shown to be involved in various pathogenic processes as well as aging. The direct scavenging effect of spermidine on DPPH radical, $H_2O_2$ and hydroxyl radical, and its protective effect against DNA oxidation related to oxidative stress were evaluated in vitro. It was observed that spermidine exhibits scavenging activities on DPPH radical and H2O2 above 500 ${\mu}M$. Spermidine was especially effective in exerting a scavenging activity on hydroxyl radical. In addition, spermidine at 1000 ${\mu}M$ showed a clear protective effect against DNA oxidation. Furthermore, the expression level of anti-oxidant enzymes such as superoxide dismutase in humam dermal fibroblasts increased in the presence of spermidine compared with blank group. These results suggest that spermidine can be used as an antioxidant to prevent ROS-related diseases including inflammation, cancer and aging.

• Journal of fish pathology
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• v.14 no.1
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• pp.3-10
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• 2001

The present study was to obtain a basic research data about medicinal herbs by screening in vitro antimicrobial activity and the production of superoxide anion($O_2^-$) from the head kidney phagocytes of olive flounder, Paralichthys olivaceus. The following fourteen kinds of medicinal herbs extracted by boiling water were used : Gosam, Gwijeonu, Gujeolcho, Bagha, Bangpung, Yeongyo, Yagssug, Jiyu, Sambaegcho, Samjiguyeobcho, Sangbaegpi, Sohwehyang, Pyeonchug, Palgag. Antimicrobial activity against fish pathogenic bacteria, Listonella anguillarum, Vibrio sp., Vibrio alginolyticus, Edwardsiella tarda, Streptococcus sp. and Lactococcus garvieae, and the production of superoxide in kidney macrophage of olive flounder were examined by disk method and nitroblue tetrazolium(NBT) reaction, respectively. Among the tested herbs, Yagssug showed the highest antimicrobial activity against those fish pathogenic bacteria and stimulation of $O_2^-$ production.

• Food Science and Biotechnology
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• v.16 no.1
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• pp.90-98
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• 2007

The antioxidant activities of water ($H_2O$) and ethanol (EtOH) extracts from hamcho (Salicornia herbacea L.) juice and cake prepared by enzymatic treatments were evaluated by in vitro assays against DPPH, superoxide, and hydroxyl radicals. Among the $H_2O$ and EtOH extracts from five different carbohydrases treated, the EtOH extract from viscozyme-treated hamcho cake had higher yield and phenolic content, and exhibited the strongest radical scavenging activity against DPPH ($IC_{50}=186.91\;{\mu}g/mL$), superoxide ($IC_{50}=87.54\;{\mu}g/mL$), and hydroxyl radicals ($IC_{50}=367.07\;{\mu}g/mL$). Antioxidant assay-guided fractionation and purification of the EtOH extract led to isolation and identification of five phenolic compounds, procatechuic, ferulic and caffeic acids, quercetin, and isorhamnetin. Most of these phenolic compounds exhibited considerable DPPH, superoxide, and hydroxyl radical scavenging activities, and in particular, caffeic and ferulic acids had stronger superoxide and hydroxyl radical scavenging activities than the well-known antioxidant radical scavenger, (+)-catechin (p<0.05). Quercetin and isorhamnetin were the primary compounds responsible for the strong antioxidant activity in the EtOH extract of the viscozyme-treated hamcho cake. Meanwhile, these five phenolic compounds were detected in the EtOH extract of the viscozyme-treated hamcho cake at the following levels (dry base of hamcho); procatechuic acid (1.54 mg%), caffeic acid (6.87 mg%), ferulic acid (8.45 mg%), quercetin (12.63 mg%), and isorhamnetin (6.65 mg%). However, three of these phenolic compounds (procatechuic, caffeic acid, and ferulic acids) were detectable in the $H_2O$ extract of viscozyme-treated hamcho juice. These results suggest that the EtOH extract of viscozyme-treated hamcho cake may be a potential source of natural antioxidants.

• Biomolecules & Therapeutics
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• v.8 no.1
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• pp.32-37
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• 2000

Recently new soybean saponins with D DMP (2,5-dihydroxy-6-methyl-2,3,- dihydro-4H-pyran-4-one) moiety have been isolated from legumes. The purpose of this study is to characterize ROS scavenging activities of DDMP saponins ($\alpha$g, $\beta$g saponin) isolated from Glycine max (L.) Merrill. The scavenging activity on OH was examined in terms of lipid peroxidation in the rat liver homogenates and the same activity on $O_2$ was also determined in the xanthine-xanthine oxidase system, respectively. Up to 0.25 mg DDMP saponins ($\alpha$g and $\beta$g saponins) did not cause any significant effects on the prevention of lipid peroxidation as compared with the control group. In terms of superoxide scavenging activities, 0.25 and 0.5 mg $\alpha$g saponin inhibits only 2.6% and 5.5% (p<0.05) of the control group, respectively. However, $\alpha$g saponin dose-dependently (p<0.01, r=0.955) inhibits the formation of superoxide radical unto 21.3% of the control group with a maximal dose of 0.5 mg (p<0.01), equivalent to 0.17 units of superoxide dismutase activity.