• Natural Product Sciences
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• 제18권2호
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• pp.111-115
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• 2012

In the course of screening for antioxidant compounds by measuring the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging effect and superoxide quenching activity, methanol extract of Cyperus flaccidus (Cyperaceae) was found to show potent antioxidant activities. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of ten compounds, kaempferol-3,7-O-${\alpha}$-L-dirhamnopyranoside (1), caffeic acid (2), quercetin-3-O-${\alpha}$-L-rhamnopyranosyl($1{\rightarrow}6$)-${\beta}$-D-glucopyranoside (3), kaempferol-3-O-${\alpha}$-L-rhamnopyranoside (4), quercetin-3-O-${\alpha}$-L-rhamnopyranoside (5), luteoiln-7-O-${\beta}$-D-glucopyranoside (6), kaempferol-3-O-${\alpha}$-L-rhamnopyranosyl($1{\rightarrow}6$)-${\beta}$-D-glucopyranoside (7), luteoiln (8), quercetin (9) and quercetin-3-O-${\beta}$-D-glucuronide (10). Their structures were elucidated by spectroscopic studies. Compounds 1 - 10 were isolated for the first time from this plant. Among them, compounds 2, 8 and 9 showed the significant radical scavenging effects on DPPH, and the potent xanthine-originated superoxide quenching activities.

• 생명과학회지
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• 제10권4호
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• pp.340-346
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• 2000

This study was designed to investigate the effects of silk fibroin(Mw 500) powder (SFP) on oxygen radicals and the scavenger enzymes in brain membranes of rats. Spragu-Dawley(SD) male rats(160${\pm}$10g) were fed basic diet(control group), and experimental diets(SFP-2.5 and SFP-5.0 groups) added 2.5 and 5.0g/kg BW/day for 6 weeks. Hydroxyl radical($.$OH) levels resulted in a decreases(6.6% and 9.7%, 2.8% and 11.9%, respectively) in brain mitochondria and microsomes of SFP-2.5 and SFP-5.0 groups compared with control group, but were significantly decreased in these membrances of SFP-5.0 group only. Superoxide radical (O2) levels were a slightly decreased (2.0% and 9.1%, respectively) in brain cytosol of SFP-2.5 and SFP-5.0 groups compared with control group. Lipid peroxide(LPO) levels were significantly decreased (12.9% and 21.9%, 13.2% and 22.5%, respectively) in brain mitochondria and microsomes of SFP-2.5 and SFP-5.0 groups compared with control group. Oxidized protein (OP) levels were significantly decreased (16.7% and 15.7%, respectively) in brain microsomes of SFP-2.5 and SFP-5.0 group compared with control group, but significantly difference between in brain mitochondria of these two groups could not be obtained. Mn-SOD activities were remarkably increased (11.2% and 24.2%, respectively) in mitochodria of SFP-2.5 and SFP-5.0 groups. CuZn-SOD activities were effectively increased (7.7% and 19.6%, respectively) in brain cytosol of SFP-2.5 and SFP-5.0 groups, but significant difference between control and SFP-2.5 groups could be not obtained. GSHPx activities were considerably increased (5.3% and 11.7%, respectively) in brain cytosol of SFP-2.0 and SFP-5.0 groups compared with control group. There results suggest that anti-aging effect of silk fibroin may play an effective learning and memory role in a attenuating a oxidative stress and increasing a scavenger enzyme activity in brain membranes.

• Bulletin of the Korean Chemical Society
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• 제30권3호
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• pp.667-670
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• 2009

The understanding of behaviors of hydroperoxyl/superoxide anion radicals (${H_2O_2}^./{O_2}^{-.}$) generated from a photoirradiated $TiO_2$ surface is essential to improve the efficiency of $TiO_2$ photocatalytic reactions by decreasing the recombination of photoinduced electron-hole ($e^--h^+$) pairs. In contrast with previous studies, we found that ${H_2O_2}^./{O_2}^{-.}$ generated on the surface of illuminated $TiO_2$ particles are mobile. ${H_2O_2}^./{O_2}^{-.}$ formed by the photocatalysis of $TiO_2$ particles immobilized onto the inner surface of a coil-quartz tube were forced under a continuous flow through a knotted tubing reactor (KTR) and into the aqueous phase completely separated from the $TiO_2$ particles, and were measured by a chemiluminescence (CL) technique using 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[ 1,2-a]pyrazin-3-one (MCLA) as the reagent. The initial concentration of the ${H_2O_2}^./{O_2}^{-.}$ stream entering the KTR was determined by its half-life (98 s) at pH 5.8. We suggests that the efficiency of $TiO_2$ photocatalytic reactions may be further improved by utilizing the mobility of ${H_2O_2}^./{O_2}^{-.}$.

• Biomolecules & Therapeutics
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• 제19권3호
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• pp.336-341
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• 2011

As part of an ongoing search for natural plants with antioxidant compounds by measuring the radical scavenging effect on 1,1-diphenyl- 2-picrylhydrazyl (DPPH), a total extract of the twigs of Galium spurium L. (Rubiaceae) was found to show potent antioxidant activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of nine compounds, asperulosidic acid methyl ester (1), asperuloside (2), caffeic acid (3), kaempferol-3-O-L-rhamnopyranoside (4), quercetin-3-O-[${\alpha}$-Lrhamnopyranosyl($1{\rightarrow}6$)-${\beta}$-D-glucopyranoside] (5), isorhamnetin-3-O-glucopyranoside (6), quercetin-3-O-${\alpha}$-L-rhamnopyranoside (7), kaempferol-3-O-[${\alpha}$-L-rhamnopyranosyl($1{\rightarrow}6$)-${\beta}$-D-glucopyranoside] (8), and quercetin (9). Their structures were elucidated by spectroscopic studies. Compounds 1, 3-8 were isolated for the first time from this plant. Among them, compounds 3 and 9 showed the significant radical scavenging effects on DPPH, and compounds 3 and 7 showed the potent riboflavin originated superoxide quenching activities.

• Biomolecules & Therapeutics
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• 제17권4호
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• pp.412-417
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• 2009

In the course of screening for antioxidant compounds by measuring the radical scavenging effect on DPPH (1,1-diphenyl- 2-picrylhydrazyl), a total extract of the twigs of Vitex rotundifolia (Verbenaceae) was found to show potent antioxidant activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of three iridoid compounds, 10-O-vanilloylaucubin (1), 10-O-p-hydroxybenzoylaucubin (2) and aucubin (3), two C-glycoside flavones, vitexin (4) and orientin (5), and a quinic acid derivative, 3,4-di-O-caffeoylquinic acid (6). Their structures were elucidated by spectroscopic studies. Among them, compounds 5 and 6 showed the significant antioxidative effects on DPPH free radical scavenging test. In riboflavin-NBT-light and xanthine-NBT-xanthine oxidase systems, compounds 5 and 6 exhibited the formation of the blue formazan in a dose-dependent manner. Compounds 5 and 6 showed better superoxide quenching activities than vitamin C.

• 약학회지
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• 제54권4호
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• pp.215-225
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• 2010

To investigate effects of pine essential oil isolated by steam distillation from Pinus densiflora needles (PN) and twigs (PT) on anti-oxidant and anti-aging activities, the experiments were carried out to determine anti-oxidant and antiaging activities on DPPH radical scavenging activity, NBT/xanthine oxidase-superoxide scavenging activity, silica-induced intracellular $H_2O_2$ and hydroxyl radical generation in RAW264.7 cells, hyaluronidase and elastase activities in vitro. Essential oil of PN and PT were contained 0.225 and 0.176 (w/v) %, respectively. PN was contained with 30 kinds of essential oil and its major constituent is $\alpha$-pinene (21.5%). Further PT was contained with 40 kinds of essential oil and its major constituent is $\beta$-pinene (22.4%) in GC/MS assay. Other essential oils of PN were $\beta$-pinene, camphene, myrcene, limonene, terpinolene, $\alpha$-terpineol, bornyl acetate, $\alpha$-copaene, caryophellene and humulene and PT were $\alpha$-pinene, camphene, phellandrene, limonene, terpinolene, $\alpha$-terpineol, bornyl acetate, $\alpha$-copaene, caryophellene and humulene. The essential oil of PT have more active than that of PN in anti-oxidant activity which has significant DPPH radical and superoxide scavenging activity, and significant inhibitory activities on silica-induced intracellular $H_2O_2$ and hydroxyl radical generation, as well as, significantly inhibited elastase and hyaluronidase activities. Further, phellandrene, myrcene and $\alpha$-pinene have DPPH radical and superoxide scavenging activities, $\beta$-pinene, terpinolene, myrcene and phellandrene inhibited silica-induced intracellular $H_2O_2$ and hydroxyl radical generations. And also phellandrene and $\beta$-pinene inhibited hyaluronidase and elastase activities. In conclusion, the essential oils isolated from PN and PT have anti-oxidant and anti-aging activities.

• International Journal of Vascular Biomedical Engineering
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• 제2권2호
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• pp.1-9
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• 2004

The history of studies in biology regarding reactive oxygen species (ROS) is approximately 40 years. During the initial 30 years, it appeared that these studies were mainly focused on the toxicity of ROS. However, recent studies have identified another action regarding oxidative signaling, other than toxicity of ROS. Basically, it is suggested that ROS are reactive, and degenerate to biomolecules such as DNA and proteins, leading to deterioration of cellular functions as an oxidative stress. On the other hand, recent studies have shown that ROS act as oxidative signaling in cells, resulting in various gene expressions. Recently ROS emerged as critical signaling molecules in cardiovascular research. Several studies over the past decade have shown that physiological effects of vasoactive factors are mediated by these reactive species and, conversely, that altered redox mechanisms are implicated in the occurrence of metabolic and cardiovascular diseases ROS is a collective term often used by scientist to include not only the oxygen radicals($O2^{-{\cdot}},\;{^{\cdot}}OH$), but also some non-radical derivatives of oxygen. These include hydrogen peroxide, hypochlorous acid (HOCl) and ozone (O3). The superoxide anion ($O2^{-{\cdot}}$) is formed by the univalent reduction of triplet-state molecular oxygen ($^3O_2$). Superoxide dismutase (SOD)s convert superoxide enzymically into hydrogen peroxide. In biological tissues superoxide can also be converted nonenzymically into the nonradical species hydrogen peroxide and singlet oxygen ($^1O_2$). In the presence of reduced transition metals (e.g., ferrous or cuprous ions), hydrogen peroxide can be converted into the highly reactive hydroxyl radical (${^{\cdot}}OH$). Alternatively, hydrogen peroxide may be converted into water by the enzymes catalase or glutathione peroxidase. In the glutathione peroxidase reaction glutathione is oxidized to glutathione disulfide, which can be converted back to glutathione by glutathione reductase in an NADPH-consuming process.

• Journal of Nutrition and Health
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• 제34권7호
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• pp.734-740
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• 2001

The purpose of this study was to investigate the effect of green tea catechins on the antioxidative defense enzyme activity of kidney in diabetic rats. Sprague-Dawley male rats weighting 100$\pm$10g were randomly assigned to one normal and three STZ-induced diabetic groups; catechin free diet(DM-0C group), 0.25% catechin diet(DM-0.25C group) and 0.5% catechin diet(DM-0.5C group). Diabetes was induced by intravenous of 55mg/Kg body weight of STZ in sodium citrate buffer(pH 4.3) after 4 weeks feeding of experimental diets. Rats were sacrified at the 6th day of diabetic states. Superoxide dismutase(SOD) activity in kidney was decreased by 25% and 20% in DM-0C and DM-0.25C groups compared with normal group, DM-0.5C group was not significantly different when compared with normal group. Glutathione peroxidase(GSHpx) activity in kidney was were no significant differences the diabetic groups compared to normal group. Xanthin oxidase(XOD) activity was increased by 110% and 63% in DM-0C and DM-0.25C groups compared with normal group, DM-0.5C group was not significantly different when compared with normal group. The contents of superoxide radical(O$_2$)in kindney were 116% and 33%, respectively, higher in DM-0C and DM-0.25C groups than normal group. DM-0.5C group and normal groups were similar levels in their superoxide radical contents of kidneys. Levels of TBARS(thiobarbituric acid reactive substance) in kidney were increased by 62% in DM-0C group, when compared with normal group, but those of DM-0.5C group were similar to that of normal groups. These results indicate that free radical generation system was weakened and free radical scavenger system was enhance in kidney of STZ-induced diabetics rats by dietary catechin. Thereby it may reduce renal disorders such as oxidative damage and aging of tissue.

• 한국자원식물학회지
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• 제23권3호
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• pp.207-213
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• 2010

Hovenia dulcis Thunb fruits were successively extracted with hot water, water, methanol, ethyl acetate, and chloroform. The crude extracts were investigated for potential antioxidant by measuring scavenging against DPPH free radicals, reducing power, superoxide radicals, and protection of protein damage and cultured cells from a lethal dose of hydrogen peroxide ($H_2O_2$). In all chemical assays used, the hot water extract of H. dulcis fruits, which contained $61.14{\pm}2.57$ (Tannic acid mg/g extract, n=3) of total phenolic compounds contents exhibited highest activity in in vitro models of DPPH free radical scavenging activity, reducing power assay, superoxide radical scavenging activity and protection of protein damage. In addition, the hot water extract protected cultured RAW 264.7 macrophages from a lethal dose of $H_2O_2$ and reduced reactive oxygen species level in RAW 264.7 cells.

• 생명과학회지
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• 제10권6호
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• pp.570-576
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• 2000

This study was designed to investigate the effects of mulberry (Morus alba L.) leaf extract (MLE) on oxygen radicals and their scavenger enzymes in brain membranes of rats. Sprague-Dawley (SD) male rats (160$\pm$10 g) were fed basic diet (control group), and experimental diets (MLE-100 and MLE-300 groups) added 100 and 300 mg/kg BW/day for 6 weeks. Hydroxyl radical (.OH) lecels resulted in significant decreases (13.4% and 21.1%, 12.0% and 13.4%, respectively) in brain mitochondria and microsome of MLE-100 and MLE-300 groups compared with control group. Superoxide radical ($O_2$) levels were significantly decreased about 12% in brain cytosol of MLE-300 group compared with control group. Lipid peroxide (LPO) levels were effectively inhibited (18.1% and 12.3%, respectively) in brain mitochondria and microsomes of MLE-300 groups compared with control group. Oxidized protein (OP) levels were significantly decreased (14.2%, and 10.9%, respectively) in brain mitochondria and microsomes of MLE-300 groups compared with control group. Mn-SOD activities in brain mitochondria were significantly increased (13.5% and 18.6%, respectively) in MLE-100 and MLE-300 groups, and Cu/Zn-SOD activities in brain cytosol were also effectively increased (about 17.7%) in MLE-300 groups compared with control group. GSHPx activities in brain cytosol were remarkably increased (17.2% and 23.9%, respectively) in MLE-100 and MLE-300 groups compared with control group. These results suggest that anti-aging effect of mulberry leaf extract (MLE) may play a pivotal role in attenuating a various age-related changes in brain.