• Journal of Applied Biological Chemistry
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• v.51 no.3
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• pp.111-116
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• 2008

Aralia elata seeds were successively extracted with water, methanol, ethanol, acetone and chloroform. The crude extracts were investigated for antioxidant and antidiabetic activities. The antioxidant properties of various extracts were evaluated by antioxidant tests, such as DPPH free radical-scavenging activity, hydroxyl radical-scavenging assay, metal-chelating activity, lipid peroxidation inhibition activity and reducing power assay. The 70% methanol extract exhibited the highest activity in the in vitro models of DPPH free radical-scavenging activity, metal-chelating activity, and reducing power assay. Acetone extract showed good effects on lipid peroxidation inhibition and hydroxyl radical-scavenging assay at a low concentration. In addition, the $\alpha$-glucosidase inhibition assay showed that 70% methanol extract had the highest activity. These results indicate the high possibility of using A. elata seeds for medical application due to their efficient antioxidant properties.

• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2557-2560
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• 2010

To assay for antioxidant capacity of natural products considered important in producing human health benefits, a practical and economical method using pellet techniques was developed. A standard visualizing reagent, 1,1diphenyl-2-picryl-hydrazyl (DPPH), was mixed with a water-miscible polyvinyl alcohol (PVA), serving as a solid phase support for the DPPH reagent. A DPPH pellet was prepared by dropping a small volume of the DPPH solution onto PET film, and drying in an oven. The PVA-based DPPH pellet was dissolved into water, in which the water-miscible PVA plays as a non-ionic surfactant to help the DPPH reagent to be dissolved into the solvent. Using the DPPH assay, the antioxidant capacity of water-soluble extracts of black soybean, barley, green tea, and green gram was examined. Among the natural products tested, green tea showed the highest antioxidant capacity. This PVA-based DPPH antioxidant assay can be further applied in the natural food, raw plant material, and health product inspection field.

• Korean Journal of Plant Resources
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• v.22 no.4
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• pp.323-329
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• 2009

In order to find out superior corn line which has a strong antioxidant activity in the corn silk, antioxidant compounds and antioxidant activity were measured from various inbred and F1 lines. As a result, the contents of phenolic and flavonoid compounds range from 532 mg/100 g to 3,274 mg/100 g and from 980 mg/100 g to 2,420 mg/100 g respectively. Absorbance at 517 nm for contents of anthocyanins ranges from 0.05 to 0.76. Correlation coefficients between antioxidant compounds and various antioxidant assays such as DPPH, ABTS and FRAP were analyzed. Correlation coefficients between antioxidant activity and phenolic compounds and anthocyanin were significantly high in ABTS and FRAP assays. Considering acidic extraction condition and intervention between anthocyanins and DPPH solution, ABTS assay and FRAP assay are more suitable methods to evaluate antioxidant activity of corn silks. Especially, ABTS assay is thought to be the best method among three assays because the antioxidant activity in ABTS assay showed high correlation with phenol, flavonoid and anthocyanin compounds respectively. Among the samples, S15 which showed the highest contents of total phenolic compounds and the most potent antioxidant activity in ABTS and FRAP assay will be a good source for functional material.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.388-394
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• 2017

Although several analytical methods for measuring total antioxidant capacity (TAC) have been applied to biological samples, there were often dissimilar results due to the different principles of methods applied. Thus, this study aimed to validate four conventional analytical methods for measuring plasma TAC, including the ABTS assay, DPPH assay, FRAP assay, and ORAC assay, by comparing with urinary 8-isoprostane concentration. In addition, TAC results were compared with antioxidant enzyme activities including superoxide dismutase (SOD) and glutathione peroxidase in erythrocyte, and catalase in plasma. Plasma TAC measure by ABTS assay was strongly correlated with the result by FRAP assay. Plasma TAC by FRAP and ORAC assays were negatively correlated with erythrocyte SOD activity. The agreement among the four TAC assay methods and 8-isoprostane was determined using 95% prediction limits of linear regression, expressed as the mean of 8-isoprostane ${\pm}95%$ prediction limits. The ABTS method better agreed with 8-isoprostane than the other methods, demonstrating narrow prediction of limits. Furthermore, only plasma TAC determined by the ABTS assay was inversely correlated with urinary 8-isoprostane (r = -0.35, p < 0.05). In summary, the ABTS assay would be an appropriate method to measure overall plasma antioxidant capacity and predict the body's antioxidant status.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.78-78
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• 2019

The aim of the study was to determine the antioxidant activities of the plants with origin of Vietnam. The Embelia scandens (Lour.) Mez which is a species of plant in the family Myrsinaceae and Cornus hongkongensis Hemsl., which is a species of plant in the family Cornaceae were tested for antioxidant activities. Samples were prepared using 95% ethanol using DPPH assay for assessing the antioxidant activity. Ascorbic acid was used for positive control for DPPH assay. DPPH assay experiment showed that extracts of the Embelia scandens (Lour.) Mez and Cornus hongkongensis Hemsl. might have anti-oxidant activity 4.77 times and 5.65 times higher, respectively, compared to control. To determine the cell toxicity, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used. MTT assay experiment showed that Embelia scandens (Lour.) Mez might have 13.1% more toxicity whereas Cornus hongkongensis Hemsl. might have 47.3% less toxicity compared to control. Taken together, these experiments showed that Cornus hongkongensis Hemsl. extracts might have significantly higher antioxidant activities and relatively lower toxicity, compared to control.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.74-74
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• 2019

The aim of the study was to determine the antioxidant activities of the plants with origin of the Far East. The Carlemannia tetragona Hook f., which is a species of plant in the family Carlemanniaceae and Celastrus virens which is a species of plant in the family Celastraceae were tested for antioxidant activities. Samples were prepared using 95% ethanol using DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical) assay for assessing the antioxidant activity. Ascorbic acid was used for positive control for DPPH assay. DPPH assay experiment showed that extracts of the Carlemannia tetragona Hook. f., and Celastrus virens might have anti-oxidant activity 54.5% and 258% higher, respectively, compared to control. To determine the cell toxicity of these plant extracts, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used. MTT assay experiment showed that Carlemannia tetragona Hook. f., and Celastrus virens might have less toxicity 23.3% and 27.5%, respectively, compared to control. Taken together, these experiments showed that Celastrus virens extracts might have much higher antioxidant activities than Carlemannia tetragona Hook. f., with relatively lower toxicity. This implies that this study might provide a basis to develop a new powerful antioxidant candidate for human diseases therapeutics.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.17 no.3
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• pp.275-286
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• 2013

In the present study, antioxidant activity and protective effect of extracts from Sambucus williamsii var. coreana stems (SWC) were evaluated on tert-butyl hydroperoxide (t-BHP) induced oxidative stress in human liver (Chang) cells. Antioxidant activities of the SWC extracts were determined by various radical scavenging activities, such as DPPH, ferric reducing antioxidant power (FRAP), 2,2'-azinobis-(3-ethybenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity and oxygen radical absorbance capacity (ORAC) assay. SWC extracts showed strong antioxidant effect on various assay. To determine the hepatoprotective effects of SWC on t-BHP induced oxidative damage, cell viability was measured using MTT assay. Pretreatment of SWC extracts showed increasing cell viability, decreasing ROS and restoring mitochondria membrane potential on t-BHP induced oxidative stress in Chang cells. Our findings suggest that SWC extracts may be considered a potential agent for therapeutic protective effect from oxidative stress through its antioxidant activity.

• Korean journal of food and cookery science
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• v.27 no.3
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• pp.1-10
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• 2011

The antioxidant activity and cytotoxic effect of an ethanol extract from Seoritae were analyzed to develop new functional food materials. The antioxidant activity of Seoritae was determined by measuring electron donating ability with 1,1-diphenyl-2picrylhydrazyl (DPPH) and 2-2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assays, as well as the ferric reducing antioxidant power (FRAP) assay. The cytotoxic effect of the Seoritae ethanol extract was measured with the 3-(4,5-dimethylthiazol-2-yl)-2,5-dipheltetrazolium (MTT) and sulforhodamine B (SRB) assays. As a result, the electron donating abilities of Seoritae against the DPPH and ABTS radicals were 63.75% and 87.68% at 500 ${\mu}g$/assay, respectively. The $IC_{50}$ values of Seoritae in the DPPH and ABTS assays were 385.39 ${\mu}g$/assay (128.46 ${\mu}g/mL$) and 209.39 ${\mu}g$/assay (51.83 ${\mu}g/mL$). Additionally, the FRAP value of Seoritae was 0.84 $FeSO_4$ eq. mM at 800 ${\mu}g$/assay. The total amounts of polyphenols and flavonoids, which indicate the antioxidant capability of Seoritae extract were 1.65 mg/g and 0.59 mg/g, respectively. Moreover, Seoritae extract showed a high cytotoxic effect of up to 81% against human cancer cells, particularly A-549 and HeLa cells. The growth inhibition rate of Seoritae extract against A-549 and HeLa cells was up to 76.48% and 75.67% in the MTT assay, and 78.98% and 80.54% in the SRB assay, respectively. The results of this study suggest that an ethanol extract of Seoritae is a potentially good natural antioxidant.

• Nutrition Research and Practice
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• v.11 no.1
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• pp.33-42
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• 2017

BACKGROUND/OBJECTIVE: This study aims to measure the in vitro antioxidant capacity of Korean diet (KD) with American diet (AD) as a control group and to examine the ex vivo DNA damage reduction effect on human lymphocytes. MATERIALS/METHODS: The KD applied in this study is the standard one-week meals for Koreans (2,000 kcal/day) suggested by 2010 Dietary Reference Intakes for Koreans. The AD, which is the control group, is a one-week menu (2,000 kcal/day) that consists of foods that Americans would commonly take in according to the National Health and Nutrition Examination Survey. The antioxidant capacity of each menu was measured by means of the total phenolic assay and 3 in vitro antioxidant activity assays (2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, trolox equivalent antioxidant capacity (TEAC), Oxygen radical absorbance capacity ($ORAC_{ROO{\cdot}}$)), while the extent of ex vivo lymphocyte DNA damage was measured by means of the comet assay. RESULTS: When measured by means of TEAC assay, the in vitro antioxidant capacity of the KD of the day was higher than that of the AD (P < 0.05) while there was no significant difference in total phenolic contents and DPPH and ORAC assays. The ex vivo lymphocyte DNA damage protective effect of the KD was significantly higher than that of the AD (P < 0.01). As for the one-week menu combining the menus for 7 days, the total phenolic assay (P < 0.05) and in vitro antioxidant capacity (P < 0.001, DPPH; P < 0.01, TEAC) of the KD menu were significantly higher than those of the AD menu. Likewise, the ex vivo DNA damage reduction rate of the Korean seven-day menu was significantly higher than that of the American menu (P < 0.01). CONCLUSION: This study demonstrates that the high antioxidant capacity and DNA damage protective effect of KD, which consists generally of various plant foods, are higher than those of typical AD.

• Preventive Nutrition and Food Science
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• v.19 no.4
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• pp.291-298
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• 2014

The aim of this study was to investigate the antioxidant activity of orange (Citrus auranthium) flesh (OF) and peel (OP) extracted with acetone, ethanol, and methanol. Antioxidant potential was examined by measuring total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (RSA), total radical-trapping antioxidant potential (TRAP), oxygen radical absorbance capacity (ORAC), and cellular antioxidant activity (CAA). The comet assay was used to determine the protective effects of OF and OP against $H_2O_2$-induced DNA damage. TPC was highest in the acetone extracts of OF and OP. DPPH RSA was also higher in the acetone extracts than in the ethanol extracts. The DPPH RSA was highest in the acetone extracts of OF. The TRAP and ORAC values of the all extracts increased in a dose-dependent manner. In the TRAP assay, the acetone extracts of OF and OP had the lowest $IC_{50}$ values. In the CAA assay, the methanol and acetone extracts of OP had the lowest $IC_{50}$ values. All of the samples protected against $H_2O_2$-induced DNA damage in human leukocytes, as measured by the comet assay, but the acetone extracts of OP had the strongest effect. These results suggest that acetone is the best solvent for the extraction of antioxidant compounds from OF and OP. Furthermore, the high antioxidant activity of OP, which is a by-product of orange processing, suggests that it can be used in nutraceutical and functional foods.