• International Journal of Oral Biology
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• v.30 no.3
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• pp.77-84
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• 2005

EGCG[(-)-epigallocatechin gallate], is a major component of green tea has been considered as a major antioxidant constituent. It has been considered as potential chemopreventive and chemotherapeutic agents. However, very little is known about the cellular actions by which EGCG mediates its therapeutic effects. Various aspects of antioxidant activity of EGCG were evaluated in this study. EGCG itself did not show significant cytotoxicity. Significant 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was observed in all ranges of concentration ($0.8-100{\mu}g/ml$) used in this study. Protective effect of EGCG against hydrogen peroxide induced cell death was observed. Relatively high lipid peroxidation inhibitory activity were detected ($IC_{50}$ was about $20{\mu}g/ml$). EGCG also dose-dependently enhanced the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in V79-4 cells. In concentrations of $100{\mu}g/ml$ of EGCG, activities of SOD, CAT and GPX were measured as 36.9 U/mg of protein, 22.9 U/mg of protein and 17.8 U/mg of protein, respectively. When these values were compared with those of the control groups (24.9 U/mg of protein, 14.9 U/mg of protein and 11.7 U/mg of protein), the relative increases were calculated as 48, 54 and 52%, respectively. Taken together, our findings suggest that EGCG can act as an antioxidant by scavenging radicals and enhancing antioxidant enzyme activities.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.427-437
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• 2019

Oxidative stress and overproduction of free radicals have been reported to be a major pathological hallmark of neurodegenerative diseases. Samultang has been known as a beneficial agent to treat liver disease and cardiovascular diseases. However, the anti-oxidant activities and neuro-protective effects of Samultang against oxidative stress still have not been evaluated yet. The aim of the present study was to investigate the anti-oxidant and protective effects of Samultang and its four herbal plants, Paeonia lactiflora (PL), Ligusticum striatum (LS), Rehmannia glutinosa (RG), and Angelica gigas (AG), in vitro system and in SH-SY5Y neuronal cells. The extracts of Samultang strongly increased the radical scavenging activities of 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical (${\cdot}OH$), and nitric oxide (NO) in a concentration-dependent manner. Furthermore, we investigated the protective effects of Samultang on cellular damage against oxidative stress induced by hydrogen peroxide ($H_2O_2$) in SH-SY5Y cells. Treatment with Samultang alleviated the oxidative stress from $H_2O_2$ by increasing the cell viability and decreasing the intracellular reactive oxygen species levels. Based on these results, we further investigated the radical scavenging effects of PL, LS, RG, and AG. In our results, PL had the highest DPPH, ${\cdot}OH$, and NO radical scavenging activities. Thus, PL has a crucial role in Samultang, which has anti-oxidative and neuro-protective effects. The present research suggests that Samultang and PL have protective roles against oxidative stress from $H_2O_2$-induced neuronal cell death.

• Journal of Food Hygiene and Safety
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• v.33 no.6
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• pp.510-515
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• 2018

In the present study, we investigated the anti-oxidant activities of selenium-treated Spinacia oleracea L. by utilizing experiments in vitro assays. The selenium content of non-treated spinach in this study was noted at $61.19{\mu}g/kg$, whereby the selenium-treated spinach which was treated by a 2000 mg/kg selenium was 1000-fold diluted, and was reported to be about 4 times higher than that of non-treated spinach. In this case, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity in the concentration of selenium-treated spinach, 0.1~1.0 mg/mL was measured as stronger than that of the identified non-treated spinach. By the same token, the DPPH radical activity of non-treated spinach and selenium-treated spinach was recorded as 46.05~52.75% and 49.52~59.09% respectively. It is emphasized that the 2,2'-azino-di-2-ethyl-benzthiazoline-sulphonate (ABTS) radical scavenging activity as revealed in the concentration of selenium-treated spinach, 0.1~1.0 mg/mL was noted as being stronger than that of non-treated spinach. The ABTS radical activity of non-treated spinach and selenium-treated spinach was 11.85~52.01% and 27.14~53.59% respectively. In this respect, the nitric oxide (NO) radical scavenging activity and reducing power activity in the concentration of selenium-treated spinach, 0.1~1.0 mg/mL was identified and noted as stronger than that of non-treated spinach. These results suggest that selenium-treated spinach could possibly be more useful as a potential antioxidant to improve human health outcomes, than the non-treated spinach.

• Journal of the Korean Society of Food Culture
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• v.28 no.5
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• pp.488-494
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• 2013

This study assessed the quality characteristics of Yanggaeng prepared with different ratios of Citrus mandarin powder: 0, 2, 4, and 6%. The moisture content was lowest in the controls, while there were no significant differences among the groups supplemented with Citrus mandarin powder. The pH significantly decreased as the amount of Citrus mandarin powder increased. The lightness (L), redness (a), and yellowness (b) were lower in control groups compared to Citrus mandarin powder groups. Texture profile analysis showed that the hardness of the Citrus mandarin powder groups were lower than the control (which was the highest). The total polyphenol and flavonoid content and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity increased as the amount of Citrus mandarin powder increased. The result of a sensory evaluation test revealed no significant differences between the controls and groups with 2% Citrus mandarin powder added in color, smell, taste, texture, and overall acceptability.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.279-286
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• 2008

The antioxidative activity of various enzymatic extracts from leaves of Perilla frutescens var. japonica was evaluated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and alkyl radical scavenging activity using an electron spin resonance (ESR) spectrometer. For this study, the leaves were enzymatically hydrolyzed by 8 carbohydrases (Dextrozyme, AMG, Promozyme, Maltogenase, Termamyl, Viscozyme, Celluclast, and BAN) and 9 proteases [Flavourzyme, Neutrase, Protamex, Alcalase, PP-trypsin (trypsin from porcine pancreas), papain, pepsin, $\alpha$-chymotrypsin, and BP-trypsin (trypsin from bovine pancreas)]. The DPPH radical scavenging activities of Promozyme and Alcalase extracts were the highest, and the $IC_{50}$ values were 77.25 and $109.66\;{\mu}g/mL$, respectively. All enzymatic extracts of the leaves scavenged hydroxyl radical, and the $IC_{50}$ values of Celluclast and pepsin extracts which were the highest activity were 243.34 and $241.86\;{\mu}g/mL$, respectively. The BAN and $\alpha$-chymotrypsin extracts showed the highest scavenging activities, and the $IC_{50}$ values were 21.13 and $33.23\;{\mu}g/mL$, respectively. The pepsin extracts from the leaves showed protective effect on $H_2O_2$-induced DNA damage. In addition, the pepsin extracts decreased cell death in PC-12 cells against $H_2O_2$-induced oxidative damage. The findings of the present study suggest that enzymatic extracts of the leaves possess antioxidative activity.

• Preventive Nutrition and Food Science
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• v.21 no.2
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• pp.110-116
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• 2016

This study was performed to evaluate and compare the antioxidant substance content and antioxidant activities of white (Superior) and colored (Hongyoung, Jayoung, Jasim, Seohong, and Jaseo) potatoes. The potatoes were extracted with 80% ethanol and were evaluated for the total polyphenol, flavonoid, and anthocyanin contents and for 1,1-diphenyl-2-picrylhydrazyl (DPPH)/2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, reducing power, and ferrous metal ion chelating effect. The total polyphenol, flavonoid, and anthocyanin contents of Hongyoung and Jayoung were higher than white and other colored potatoes. All colored potato extracts, except for Jaseo and Seohong, showed higher ABTS radical scavenging activities than the general white potato extract. Hongyoung and Jayoung had the highest ABTS and DPPH radical scavenging activities. Optical density values for the reducing power of Jayoung and Jaseo at concentration of 2 mg/mL were 0.148 and 0.090, respectively. All colored potato extracts had lower ferrous metal ion chelating effect than the white potato. A significant (P<0.05) positive correlation was observed between total polyphenol content and total flavonoid content (r=0.919), anthocyanin content (r=0.992), and ABTS radical scavenging activity (r=0.897). Based on these results, this research may be useful in developing the Hongyoung and Jayoung cultivars with high antioxidant activities.

• Food Science and Biotechnology
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• v.15 no.3
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• pp.437-440
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• 2006

To explore the possible usefulness of ${\beta}$-glucans as natural antioxidants, the antioxidant profiles of ${\beta}$-glucan, extracted from Saccharomyces cerevisiae KCTC 7911, and water soluble and insoluble mutant ${\beta}$-glucan, isolated from yeast mutant S. cerevisiae IS2, were examined by five different in vitro evaluation methods: lipid peroxidation value (POV), nitric oxide (NO), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, reducing power, and ${\beta}$-carotene diffusion assay. The antioxidant activities of all ${\beta}$-glucans evaluated in POV test were comparable to or better than that of the known antioxidant, vitamin C. Remarkably, the ${\beta}$-glucan and water insoluble mutant ${\beta}$-glucan possessed 2.5-fold more potent activity than vitamin C at a dosage of 2 mg. Although vitamin C showed 100-fold greater activity than all ${\beta}$-glucans in NO and DPPH tests for measuring the radical scavenging capacity, all ${\beta}$-glucans revealed higher radical scavenging activity than the known radical scavenger, N-acetyl-L-cysteine (NAC), in DPPH test. The water insoluble mutant ${\beta}$-glucan had 2.6- and 5-fold greater antioxidative activity than water soluble ${\beta}$-glucan in NO and DPPH tests, respectively, showing that all ${\beta}$-glucans were able to scavenge radicals such as NO or DPPH. While all ${\beta}$-glucans revealed lower antioxidant profiles than vitamin C in both reducing power activity and ${\beta}$-carotene agar diffusion assay, the ${\beta}$-glucan and water insoluble mutant ${\beta}$-glucan did show a marginal reducing power activity as well as a considerable ${\beta}$-carotene agar diffusion activity. These results confirmed the potential usefulness of these ${\beta}$-glucans as natural antioxidants.

• The Korea Journal of Herbology
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• v.31 no.6
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• pp.21-28
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• 2016

Objectives : This study was performed to investigate the antioxidant activity of water extracts from Lycopus lucidus Turcz. ex Benth. leaves, stems and roots at the $100{\mu}g/m{\ell}$ concentration. Methods : The different part of Lycopus lucidus Turcz. ex Benth. extract was prepared using water. The antioxidant activities of polyphenol contents, total flavonoid contents, DPPH(1,1-diphenyl-2-picrylhydrazyl) free-radical scavenging activity, SOD like activity, hydroxyl radical, ABTS(2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), $Fe^{2+}$ chelating, and nitrite scavenging activity. Results : The total polyphenol and total flavonoid content of leaves were the highest at $221.85{\mu}g/mg$ and $794.13{\mu}g/mg$, respectively. Electron donating ability was the 79.68% in the water extract from leaves. The ABTS radical scavenging activity of the hot extracts, leaves ${\gg}$ roots > stems was higher in the order. It was shown the highest at 94.53% in the water extract from leaves, which showed a value equal to 94.7% of ascorbic acid. The hydroxyl radical scavenging activity was the highest at 8.07% in the water extract from leaves. SOD like activity and $Fe^{2+}$chelating activity were leaves of 12.3% and 27%, respectively, which were much higher than those of any other parts. The nitrite scavenging ability of extracts was increased at pH 2.5, and those was the highest in leaves of 83.03%. Its were more than twice the 41.61% of BHT. Conclusion : The results suggest that Lycopus lucidus Turcz. ex Benth. can be used as nutraceutical foods and natural antioxidant.

• Journal of Dairy Science and Biotechnology
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• v.41 no.3
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• pp.113-125
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• 2023

In this study, we explored the synergistic effects of whey protein concentrate (WPC) and soybean protein components after fermentation with lactic acid bacteria isolated from kimchi, and identified several peptides with desirable physiological functions, proteolysis, and immune effects. Antioxidant activity was determined using 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid, 1,1-diphenyl-2-picrylhydrazyl, ferric-reducing antioxidant power, and hydroxyl radical scavenging assays, followed by cross-validation of the four antioxidant activities. These assays revealed that samples with a 8:2 and 9:1 whey to soy ratio possessed higher antioxidant activity than the control samples. Antibacterial potency testing revealed high antibacterial activity in the 9:1 and 8:2 samples. Cytotoxicity testing of samples using 3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide revealed that only the 10:0, 1:9, and 0:10 samples had <80% viable cells, indicating no significant cytotoxicity. Nitric oxide (NO) assays revealed that NO expression was reduced in 8:2, 5:5, and 0:10 protein ratio fermentations, indicating low inflammatory reaction stimulatory potential. Cytokine expression was confirmed using an enzyme-linked immunosorbent assay kit. The 8:2 sample had the lowest inflammatory cytokine (interleukin [IL]-1α, IL-6, and tumor necrosis factor-α) levels compared with the lipopolysaccharide-treated group. Amino acid profiling of the 8:2 sample identified 17 amino acids. These results suggest that inoculating and fermenting Lactobacillus plantarum DK203 and Lactobacillus paracasei DK209 with an 8:2 mixture of WPC and soybean protein releases bioactive peptides with excellent anti-inflammatory and antioxidant properties, making them suitable for functional food development.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.983-989
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• 2008

Two flavonoids, isorhamnetin 3-O-$\beta$-D-glucopyranoside (1) and quercetin 3-O-$\beta$-D-glucopyranoside (2), from slander glasswort (Salicornia herbacea, Korean name hamcho) were isolated. Antioxidative and matrix metalloproteinase-9(MMP-9) inhibitory effects of these compounds were investigated in HT 1080 cell lines. These compounds suppressed the electron spin resonance (ESR) signal intensity on generation of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical in a free-cellular system. Their scavenging effects on generation of intercellular reactive oxygen species (ROS) also exhibited similar trends with DPPH radical in the free cellular system. Also, a control group combined only with Fe(II)-$H_{2}O_2$ resulted in DNA apoptosis by oxidative stress, whereas treatments with these compounds suppressed radical-mediated DNA damage. Intracellular glutathione (GSH) levels were slightly increased in the presence of compound 1 and 2. Moreover, these compounds led to the reduction of the expression levels of MMP-9 without cytotoxic influence. These results suggest that these compounds have a potential as a valuable natural antioxidant and MMP inhibitor related to oxidative stress. Therefore, these compounds not only can be developed as a candidate for a therapeutic potential but also a source for use as ingredients of health foods or functional foods to prevent metastasis involving MMP-9, closely related to ROS.