• Journal of Korean Academy of Nursing
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• v.33 no.2
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• pp.170-178
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• 2003

Purpose: This study was to determine the effect of oral vitamin C supplements on blood sugar and antioxidative status in Types II diabetes mellitus patients. Method: Data for the study were collected from June 24 to August 31, 2001. Participants(31) took 1g/day vitamin C for 4 weeks, after a 1 - week taking no Vitamin C, followed by Vitamin C 3g/day for 4 weeks. A baseline blood sample was obtained following a 12hour overnight fast and at the end of each 4week Vitamin C administration. Blood samples were taken for plasma vitamin C concentration, fasting blood sugar, HbA1c, superoxide scavenging activity and hydrogen peroxide scavenging activity. The data were analyzed by SPSS for repeated measures ANOVA. Result: Plasma vitamin C concentration was significantly increased over dose(F=3.316, p=.043). Fasting blood sugar and HbA1c was significantly decreased over dose(F=13.192, p=.000; F=11.995, p=.000). Superoxide scavenging activity and hydrogen peroxide scavenging activity was significantly increased over dose(F=486.138, p=.000; F=177.704, p= .000). Conclusion: The results suggest that megadose vitamin C supplementation may have a beneficial effect in diabetes mellitus patients on both glycemic control and antioxidant status. Thus dietary measures to increase plasma vitamin C may be an important health strategy for reducing the compliance of diabetic patients

• Preventive Nutrition and Food Science
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• v.12 no.2
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• pp.65-73
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• 2007

Sargassum fulvellum, a marine brown alga, is a popular low priced edible plant in Korean markets. The polysaccharide fraction of the alga was separated and investigated for its radical scavenging activities and the results compared with those of commercial fucoidans (Fucus vesiculosus and Undaria pinnatifida), BHA and ${\alpha}$-tocopherol. The polysaccharide fraction of S. fulvellum showed a promising DPPH radical scavenging activity than did other fucoidans. Moreover, the sample exhibited a dose-dependent activity on hydrogen peroxide scavenging activity in the V79-4 cell line. Interestingly, all the tested polysaccharide counterparts were more potent NO. scavengers than were the commercial antioxidants, BHA and ${\alpha}$-tocopherol. The sulfated polysaccharide of S. fulvellum had an approximate molecular weight of 529 kDa and mainly consisted of fucose and galactose, and minor amounts of mannose, rhamnose and xylose.

• Preventive Nutrition and Food Science
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• v.13 no.3
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• pp.176-181
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• 2008

This study analyzed the some of the physiological activities of 70% ethanol extracts of specialty rough rice ('Goami2', 'Keunnunbyeo', and 'Heugkwangbyeo' rough rice cultivars) before and after germination. The physiological activities of the extracts were analyzed for their inhibition of linoleic acid peroxidation, hydrogen peroxide radical scavenging activity, superoxide dismutase-like activity, xanthine oxidase inhibitory activity, and nitrite scavenging effects. The most active rough rice cultivar was 'Heugkwangbyeo' and germinated 'Heugkwangbyeo' rough rice was more effective than ungerminated rough rice, having higher inhibition activity of linoleic acid peroxidation (1.2-fold), hydrogen peroxide radical scavenging activity (1.4-fold), superoxide dismutase-like activity (1.2-fold), and xanthine oxidase inhibitory activity (1.1-fold). The nitrite scavenging effect was increased after germination (2.1-fold) and decreased as pH increased. According to the results obtained in this study, 70% ethanol extracts from germinated 'Heugkwangbyeo' rough rice can be used for industrial applications such as the functional food materials.

• Journal of Marine Bioscience and Biotechnology
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• v.9 no.2
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• pp.43-48
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• 2017

Temperature is a major factor that affects the physiochemical properties of compounds. This study focus on the determination of thermostability and the effect of temperature on antioxidant activities of Ecklonia cava (E. cava) ethanoic extract. The ethanoic extracts of E. cava were evaluated at $30^{\circ}C$, $60^{\circ}C$ and $90^{\circ}C$ for 0 to 7 days. The antioxidant activities were determined by DPPH, hydroxyl radical and hydrogen peroxide scavenging activities. The intracellular reactive oxygen species (ROS) scavenging activity was investigated using DCFH-DA assay. Results revealed that the ethanoic extract of E. cava incubated at different temperatures for 0 to 7 days, showed stable scavenging activities on DPPH, hydroxyl radical and hydrogen peroxide. The ROS scavenging activities of ethanoic extract and ascorbic acid were also investigated. The extract showed a stable ROS scavenging activity from 0 to 7 day at $90^{\circ}C$. However, the scavenging activity of ascorbic acid at $90^{\circ}C$ decreased starting from day 3. These results indicated that the antioxidant effects of this food grade ethanoic extract of E. cava could remain stable during the employed temperatures of food processing.

• Journal of Life Science
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• v.26 no.7
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• pp.782-788
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• 2016

To check the possibility of using natural extracts for cosmetic substances, we tested the bioactive effects of 11 crude extracts originating from native plants grown in the Republic of Korea on anti-oxidant and anti-wrinkle activities. When DPPH scavenging activities were measured, the crude extracts of Vitex rotundifolia, Scirpus triangulatus, S. wichurae, S. tabernaemontani, and Aeschynomene indica assays had more than 70% of DPPH scavenging activities at 100 μg/ml concentration. The data from the hydrogen peroxide scavenging assay revealed that the crude extracts from the 10 species, except for Eleocharis mamillata var. cyclocarpa, could scavenge more than 90% at 1,000 μg/ml concentration. The crude extract of V. rotundifolia had the highest xanthine oxidase scavenging activity at a 1,000 μg/ml concentration. Based on the four anti-oxidant assays, the crude extracts of V. rotundifolia, S. triangulatus, S. wichurae, S. tabernaemontani, and A. indica were shown to have excellent anti-oxidant capacities overall. In addition to the anti-oxidant capacities, the crude extract from S. wichurae exhibited high collagenase inhibitory activity, therefore, it could be a promising candidate for a cosmetic ingredient with anti-oxidant and anti-wrinkle qualities. The results of this study indicate that many wild plants native to the Korea Peninsula can be used as excellent natural substances for cosmetics based on their bioactive effects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.5
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• pp.524-529
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• 2006

Chemical compounds, hydrogen peroxide and nitrite-scavenging activities of Phellinus baumii (PB) were investigated to expand the utilization of PB as functional food material. Total mineral contents of PB was 534.3 mg% and potassium was the highest content being 224 mg%. Total and reducing sugars were 56.2% and 9.8%, respectively The contents of free amino acids (FAAs) were in a range of $16.9{\sim}765.5mg%$ with the major FAAs of phenylalanine, aspartic acid, glutamic acid, leucine, serine and valine. The contents of total phenolic compounds in methanol and hot water extracts of PB were 33.3 and 20.7 mg/100 mL, respectively and were higher than those of other solvent extracts. Hydrogen peroxide-scavenging activity (80%) of methanol extract at $10{\mu}g/mL$ for 30 min was similar to tocopherol (83.1%) as control. Nitrite-scavenging activity of extracts of methanol and hot water at 500 mg/mL and pH 1.2 were 57.3% and 51.8%, respectively and then their effects were increased by lowering pH. The present results showed that the methanol and water extracts of Phellinus baumii exhibited strong hydrogen peroxide and nitrite-scavenging activities.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.273-279
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• 1998

The ability of bovine intact red blood cells to scavenge superoxide and hydrogen peroxide by superoxide dismutase, catalase and glutathione peroxidase was investigated. Intact red cells(up to 0.4%) suspensions did not inhibit ferricytochrome c reduction by superoxide in the superoxide generating system. On the other hand, intact red cell(0.4%) suspensions almost completely inhibit ferrocytochrome c oxidation by hydrogen peroxide. The ability of intact red cells to scavenge hydrogen peroxide was mainly attributed to either membrane bound catalase or glutathione peroxidase. The scavenge of hydrogen peroxide by 0.1~0.2% intact red cells showed a trend of dependence on mainly glutathione peroxidase. However, at blood cell concentration higher than 0.3%, the process depended upon peroxidase-independent scavengers like catalase. Enhancement of ferrocytochrome c oxidation by red cells treated with aminotriazole proved that the protection against hydrogen peroxide was due to catalase, while the protection in the presence of glutathione indicated scavenging effect of glutathione peroxidase against hydrogen peroxide.

• Advances in Traditional Medicine
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• v.4 no.3
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• pp.197-209
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• 2004

The study was aimed at evaluating the antioxidant and antimicrobial activities of methanol extract of Caesalpinia bonducella leaves (MECB) (Family: Caesalpiniaceae). The effect of MECB on antioxidant activity, reducing power, free radical scavenging (DPPH radical, nitric oxide radical, superoxide anion radical, hydroxyl radical and hydrogen peroxide radical scavenging), total phenolic content and antimicrobial activities were studied. The antioxidant activity of MECB increased in a dose dependent manner. About 50, 100, 250 and 500 g of MECB showed 53.4, 61.2, 69.1 and 76.2 % inhibition respectively on peroxidation of linoleic acid emulsion. Like antioxidant activity, the effect of MECB on reducing power increased in a dose dependent manner. The free radical scavenging activity of MECB was determined by DPPH radical scavenging method. The potency of this activity was increased with increased amount of extract. MECB was found to inhibit the nitric oxide radicals generated from sodium nitroprusside $(IC_{50}\;=\;102.8\;g/ml)$ whereas the $IC_{50}$ value of curcumin was 20.4 g/ml. Moreover, the MECB was found to scavenge the superoxide generated by photoreduction of Riboflavin. MECB was also found to inhibit the hydroxyl radical generated by Fenton reaction, where the $IC_{50}$ value is 104.17 g/ml compared with catechin 5 g/ml, which indicates the antioxidant activity of MECB. The MECB capable of scavenging hydrogen peroxide in a concentration-dependent manner. The amounts of total phenolic compounds were also determined. Antimicrobial activities of MECB were carried out using disc diffusion methods with five Gram positive, four Gram negative and four fungal species. The results obtained in the present study indicate that MECB leaves are potential source of natural antioxidant and antimicrobial agents.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.106-110
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• 2000

We investigated the active oxygen scavenging activity and active compound from Humulus japonicus. The ethyl acetate and butanol fraction exhibited strong scavenging effects on hydroxyl radical. Furthermore active compound was isolated and purified using Amberlite XAD-2 column chromatography and preparative HPLC from ethyl acetate fracton, and major compound was identified as a luteolin-7-O-$\beta$-D-glucoside by the MS, UV, 1H-NMR and 13C-NMR analyses. Luteolin-7-O-$\beta$-D-glucoside exhibited strong scavenging effect on active oxygens such as superoxide radical, hydroxyl radical and hydrogen peroxide.

• Biomolecules & Therapeutics
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• v.13 no.3
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• pp.150-155
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• 2005

The ethanolic extract of chestnut (Castanea crenata S. et Z., Fagaceae) inner shell (CISE) and one of its components, ellagic acid (EA), were evaluated for their protective effects against 1, 1-diphenyl-2-picryl hydrazine (DPPH) free radical generation and hydrogen peroxide-induced oxidative DNA damage in a mammalian cell line. CISE and EA were shown to possess the free radical scavenging effect against DPPH radical generation, significantly. They were also found to strongly inhibit hydrogen peroxide-induced DNA damage from Chinese hamster lung (CHL) cell, assessed by single cell gel electrophoresis assay and 8-hydroxy -2'-deoxy guanosine (8-OH-2'dG) assay. Furthermore, topical application of CISE [$12.5\%$(w/w) cream] and ellagic acid [$1.0\%$(w/w) cream] for 14 days potently inhibited malondialdehyde (MDA) formation of mouse dorsal skin (a marker of lipid peroxidation) induced by ultraviolet B exposure. Therefore, CISE and its component, ellagic acid, may be the useful natural antioxidants by scavenging free radicals, inhibition of lipid peroxidation and protecting oxidative DNA damage when topically applied.