• Journal of Microbiology and Biotechnology
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• v.28 no.1
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• pp.1-11
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• 2018

An antioxidant peptide derived from Pinctada fucata meat using an Alcalase2.4L enzymatic hydrolysis method (named AOP) and identified by LC-TOF-MS has promising clinical potential for generating cosmetic products that protect skin from sunshine. To date, there have been few published studies investigating the structure-activity relationship in these peptides. To prepare antioxidant peptides better and improve their stability, the design and expression of an antioxidant peptide from Pinctada fucata (named DSAOP) was studied. The peptide contains a common precursor of an expression vector containing an ${\alpha}$-helix tandemly linked according to the BamHI restriction sites. The DNA fragments encoding DSAOP were synthesized and subcloned into the expression vector pET-30a (+), and the peptide was expressed mostly as soluble protein in recombinant Escherichia coli. Meanwhile, the DPPH radical scavenging activity, superoxide radical scavenging activity, and hydroxyl radical scavenging activity of DSAOP $IC_{50}$ values were $0.136{\pm}0.006$, $0.625{\pm}0.025$, and $0.306{\pm}0.015mg/ml$, respectively, with 2-fold higher DPPH radical scavenging activity compared with chemosynthesized AOP (p < 0.05), as well as higher superoxide radical scavenging activity compared with natural AOP (p < 0.05). This preparation method was at the international advanced level. Furthermore, pilot-scale production results showed that DSAOP was expressed successfully in fermenter cultures, which indicated that the design strategy and expression methods would be useful for obtaining substantial amounts of stable peptides at low costs. These results showed that DSAOP produced with recombinant Escherichia coli could be useful in cosmetic skin care products, health foods, and pharmaceuticals.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.648-654
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• 2004

Physiological functionality of browned oak mushroom was evaluated with focusing its electron-donating ability to DPPH radicals, scavenging ability to superoxide radicals and hydroxyl radicals, and inhibitory activity on lipid peroxidation. The results showed that overall antioxidative activities of browned oak mushroom were superior to those of raw oak mushroom with marketable quality, implying possible involvement of resultant browning reaction products in an increment of antioxidativity. The increased radical-scavenging ability was suggested to mainly be exerted by direct quenching of both superoxide and hydroxyl radicals, not by inhibition of xanthine oxidase activity and $Fe^{2+}$ chelation, respectively. Collectively, these results indicate a possible use of unmarketable browned mushroom as a material for manufacturing various processed functional foods.

• Journal of the Korean Society of Food Culture
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• v.31 no.5
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• pp.481-488
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• 2016

The objective of this study was to investigate the antioxidant and anti-inflammatory activities of Eugenia caryophyllata Thunb. water and 70% ethanol extracts. The content of total polyphenol was significantly higher in water extract than in 70% ethanol extract. The DPPH radical scavenging activity of water extract was similar to that of Vit. C at a concentration of $1,000{\mu}g/mL$. The ABTS radical scavenging activities of water and 70% ethanol extract were similar to that of Vit. C at a concentration of $1,000{\mu}g/mL$. SOD-like activity of water extract was higher than that of 70% ethanol extract at a concentration of $1,000{\mu}g/mL$ but lower than that of Vit. C. The DPPH radical scavenging activity, ABTS radical scavenging activity, and SOD-like activity increased as concentrations of water and 70% ethanol extracts increased. Cell cytotoxicity was not observed at all concentrations except at $100{\mu}g/mL$ concentration of water extract. Inhibitory activity on NO production effect of water extract was significantly higher than that of 70% ethanol extract. These results show that E. caryophyllata Thunb. has potent biological activities, and their activities were different depending on extraction solvent.

• Korean Journal of Plant Resources
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• v.23 no.3
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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.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.123-130
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• 2005

Hydrogen-donating capacity, scavenging activity of reactive oxygen including superoxide anion radical and hydrogen peroxide, metal-chelating activity, and reducing power of garlic extracts were investigated. All tested garlic extracts exhibited in vitro antioxidant activities, with Uiseong extract showing highest hydrogen-donating and hydrogen peroxide-scavenging activities, and reducing power, followed by Seosan and Samchek extracts, in proportion to total thiosulfinate contents. Higher scavenging activity of superoxide anion radical was observed in Uiseong than Seosan and Samchek extracts. Metal-chelating activity increased in order of Uiseong < Seosan < Samchek, showing inverse relations to total thiosulfinate content. Garlic extracts of Uiseong and Seosan showed weak prooxidant activities and that of Samchek showed strong antioxidant activity against $Cu^{+2}$-induced human LDL oxidation. Protective effects on peroxyl and hydroxyl radical-induced DNA strand damages were observed in all tested garlic cloves. These results indicate growing conditions of garlic cloves affect total thiosulfinate content and antioxidant activities.

• Advances in Traditional Medicine
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• v.3 no.4
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• pp.205-211
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• 2003

Stem bark of Cinchona sp. (Rubiaceae) is one of the well known drugs for its therapeutic values in traditional as well as modern medicine. Even though a lot of work has been carried out on quinoline alkaloids of Cinchona, its phenolic constituents received very little attention. In the present study, we evaluated antioxidant properties of C. officinalis stem bark methanolic extract and water extract containing phenolic compounds (total phenolics 21.37, 5.18% w/w respectively in the two extracts) in different in vitro and ex vivo models viz., antiradical activity by DPPH reduction, superoxide radical scavenging activity in riboflavin/light/NBT system, nitric oxide radical scavenging activity in sodium nitroprusside/Greiss reagent system and inhibition of lipid peroxidation induced by iron-ADP-ascorbate in liver homogenate and haemolysis of erythrocytes induced by phenylhydrazine in erythrocyte membrane stabilization study. Both the extracts exhibited very good antioxidant activity in all the models tested. The phenolic compounds including tannins present in the stem bark seem to offer protection from the oxidative damage.

• 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.

• The Korean Journal of Food And Nutrition
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• v.7 no.3
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• pp.169-176
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• 1994

Screening was performed on edible natural sources to examine superoxide radical scavenging activities by using the method of superoxide dismutase assay. Among 47 kinds of samples, the extract of Capsella bursa-pastoris showed a potent superoxide radical scavenging activity of 11.6 unit / mg solid and was selected for further studies. In order to select optimal extraction solvent system, Cappella bursa-pastoris was extracted with various solvents and the electron donating abilities and inhibitory effects on lipid peroxidation of linoleic acid were measured. Among them, the ethanol extract of Capsella bursa-pastoris possessed the highest level of activities. The ethanol extract of Cappella bursa-pastoris was found to have an inhibitory effect on autoxidation of soybean oil at 5$0^{\circ}C$ from peroxide value, conjugated diene value and refractive index. In the soybean oil containing 0.2% of ethanol extract, induction period was increased 2 times in comparison with control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.411-416
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• 1997

To examine the free radical scavenging activities from buckwheat, Suwon No. 5 was extracted with various solvents. The seed of Suwon No. 5 had a high contents of carbohydrate, but the vegetable of that had a 31.4% of protein, 28.6% of ash and 25.7% carbohydrate as moisture free basis. Phenols contents of vegetable extracts had higher than those of seed extracts. Acetone extract of vegetable showed the greatest electron donating ability. Butanol and acetone extracts of vegetable showed high inhibitory effect on lipid peroxidation. Acetone extract of vegetable has also excellent activity in the superoxide radical scavenging activity by xanthine/xanthine oxidase-cytochrome c reduction system. The inhibitory effects of extracts on xanthine oxidase were measured. Acetone extract had the strongest inhibitory effect on xanthine oxidase and $IC_{50}$ was 2.2$\mu\textrm{g}$.

• Food Science and Preservation
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• v.22 no.4
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• pp.577-584
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• 2015

The objective of this study was to investigate the antioxidant activity of imported tropical and subtropical fruits including dragon fruits, green kiwi, papaya, pineapple, pomegranate, and yellow mango. A seventy percent of ethanol extracts were prepared. Total phenolic content, DPPH (1,1-diphenyl-2-picryl hydrazyl)-, ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)), superoxide anion radical scavenging activity, FRAP (ferric reducing antioxidant power), tyrosinase inhibitory activity, and reducing power were investigated for the comparisons of antioxidant activities. The phenolic content expressed as gallic acid equivalents (GAE) was found to be highest in pomegranate (12.22 mg GAE/g), followed by pineapple (3.77 mg GAE/g). Pomegranate and pineapple exhibited higher antioxidant activity than those of other fruits except for FRAP. DPPH and ABTS radical scavenging activity from pomegranate were 93.00%, and 98.98%, respectively, at a concentration of 5 mg/mL, which were equal to those of ascorbic acid used for a positive control.