• Preventive Nutrition and Food Science
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• v.13 no.3
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• pp.182-189
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• 2008

In this study, the effect of pH on the antioxidative activities of melanoidins formed as a result of the reaction between sugars, glucose (Glc) or fructose (Fru), and amino acids, L-asparagine (L-Asn) and D-asparagine (D-Asn) are examined. For this purpose, antioxidative activities were evaluated on the basis of reducing power, including ferric reducing/antioxidant power (FRAP) and free radical scavenging activity includes 1,1-diphenyl-2-picryl- hydrazil (DPPH) and 2,2'-azinobis(3-ethylbenothiazoline-6-sulfonic acid) diammonium salt (ABTS) and ferrous ion chelating activity. Ethylene diamine tetraacetate (EDTA) and trolox, a water-soluble analog of tocopherol, were used as reference antioxidant compounds. The antioxidative activities of the melanoidins at a pH of 7.0 were greater than those with a pHs of 4.0 and pH 10.0. Especially, it was found that the melanoidins formed from D-isomers are more effective antioxidants in different in vitro assays. The reducing power and chelating activity of the melanoidins formed from the Fru systems were higher than those of the melanoidins formed from the Glc systems. However, the ABTS radical scavenging activity of the melanoidins formed from the Glc systems were higher than those of the melanoidins formed from the Fru systems. In particular, the DPPH radical scavenging activity and the FRAP of the melanoidins showed different antioxidative activities according to pH level.

• Biomedical Science Letters
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• v.26 no.4
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• pp.296-301
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• 2020

The purpose of this study was performed to evaluate antioxidant activity of the Artemisia asiatica Nakai and Moringa oleifera Lam mixture extract. Mixture extracts were manufactured by concentration and compared with a single extract (only the Artemisia asiatica Nakai mixture and only the Moringa oleifera Lam mixture). The experiments conducted Total polyphenol measurements, Total flavonoid measurements, DPPH radical scavenging activty, ABTS radical scavenging activty and LDH assay. The LDH assay assessment shows that all extracts are cells compared to controls. The toxicity was weak. Finally, The antioxidant capacity was rated higher than mixture extract of a single extract. Also, the optimized mixture was determined AM5 (Artemisia asiatica Nakai mixture: Moringa oleifera Lam mixture = 3:1). For extracts of AM5, Total phenol and flavonoid contents were 271.769±18.087 mg/g and 45.384±5.026 mg/g. and DPPH and ABTS scavenging activity were 70.8±6.496% and 77.1±9.634%. Therefore, it is expected that the value of the extract will increase as it increases its antioxidant activity if it is manufactured according to the appropriate ratio.

• Korean Journal of Plant Resources
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• v.27 no.6
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• pp.642-649
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• 2014

The antioxidant potentials of the methanol extract and its various fractions from Agrimonia pilosa Ledeb were measured as 1,1-diphenyl-2-picrylhydrazyl (DPPH), and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging abilities as well as the reducing power decreasing NO in vitro. The methanol extract of Agrimonia pilosa Ledeb showed significantly strong scavenging effects on free radicals of DPPH, ABTS, and NO. Hexane fraction (HF), ethyl acetate fraction (EF) and n-butyl alcohol fraction (BF) were prepared by solvent fractionation. By comparison of polyphenol contents among BF and HF, EF with high polyphenol contents showed the highest DPPH, ABTS, and NO scavenging effects with the value of 50.2%, 80.4%, and 65.7%, respectively, at the highest tested dose. HPLC analysis revealed the presence of various phenolic compounds in EF of Agrimonia pilosa Ledeb. These results suggest that EF could be considered as natural antioxidant sources and dietary nutritional supplements to prevent oxidation-related diseases.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.125-130
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• 2009

Intact black raspberry fruits, which were crushed by hand or ground using a blender, were immersed in 20%, 40%, 60%, and 80% ethanol (125 g fruits per 900 mL ethanol) and exuded for 30, 60, and 90 days at room temperature. Monomeric anthocyanin contents (MAC) and polyphenol contents (PHC) of the exudates were determined measuring absorbance using a spectrophotometer. DPPH and ABTS free radical scavenging activities (50%: $SC_{50}$) were determined for the antioxidant activities of the exudates. Twenty % ethanol exudates from black raspberry had significantly lower MAC and PHC regardless of the fruit types. $SC_{50}$ were higher in 20% ethanol exudates, suggesting 20% ethanol exudates from black raspberry had lower antioxidant activities. MAC and PHC of the black raspberry exudates decreased with time. This study suggests that MAC and PHC in the black raspberry could be exuded more efficiently using 40% or higher concentration of ethanol and that crushing and grinding little affect exuding MAC and PHC. The exudates with higher MAC and PHC showed higher antioxidant activities.

• Journal of Life Science
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• v.33 no.2
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• pp.138-148
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• 2023

This study compared and analyzed the antioxidant activities of various organic solvent fractions from the leaves and roots of Peucedanum insolens Kitagawa. For this study, the dried leaves and roots of P. insolens Kitagawa were first extracted using 70% ethanol. The extracts were sequentially sub-fractionated in the order of hexane, chloroform, ethyl acetate, n-butanol, and water. The results revealed that the distribution of total phenolic contents by organic solvent fractions showed the same pattern in both the leaves and roots, with the highest in the ethyl acetate fraction (101.1±1.0 mg vs 71.2±3.4 mg of GAE/mg), but the lowest content in the hexane fraction (9.5±0.2 mg vs 7.5±2.1 mg of GAE/mg). The distribution of total flavonoid content in the organic solvent fractions showed the same pattern as that of total phenolic content. The results of DPPH, ABTS, and FRAP assays showed that the leaf and root extracts exhibited free radical scavenging activity in the same pattern, particularly, the ethyl acetate fraction had the highest activity. These results indicate that not only the roots of P. insolens Kitagawa but also the leaves possess potential substances that exhibit strong antioxidant activity. Significant correlations (R=0.903, p<0.0001, DPPH radical; R=0.891, p<0.001, ABTS radical; R=0.745, p<0.05, FRAP radical) between total phenolics and radical scavenging activities, but also significant correlations (R=0.867, p<0.001, DPPH vs. ABTS radicals; R=0.882, p<0.0001, DPPH vs. FRAP radicals; R=0.973, p<0.0001, ABTS vs. FRAP radicals) between radical scavenging activities were found in the organic solvent fractions. Therefore, as in the roots of P. insolens Kitagawa, the leaves possess strong antioxidant capacity and can be used as the main antioxidant material.

• Korean journal of food and cookery science
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• v.31 no.2
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• pp.207-213
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• 2015

Free amino acid and mineral analysis of beverages with Gugija (Lycii fructus) extracts performed to determine the antioxidative and anti-diabetes activities of the beverages. The four major free amino acids in the water- or ethanol-extracts of the Gugija beverages were asparagine (115.23, 51.95 mg%), methionine (20.02, 22.07 mg%), aspartic acid (19.65, 13.72 mg%) and taurine (18.64, 22.44 mg%). The mineral contents of the Gugija beverages with water- and ethanol-extracts were in the order K>Mg>Na>Ca>Zn>Fe. Antioxidant activity determined by DPPH and ABTS radical scavenging activity. There was no significant difference in DPPH and ABTS radical scavenging activities between the water-extract beverages and the ethanol-extract beverages, although more phenolics and flavonoids were found in the ethanol-extract beverage. Higher anti-${\alpha}$-glucosidase activity was observed in the ethanol-extract beverage compared to acabose, which was used as the control and is an inhibitor of ${\alpha}$-glucosidase, suggesting that the Gugija beverage with ethanol extract could be a potential hypoglycemic agent.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1315-1329
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• 2015

The objective of this study was to investigate anticytotoxic and antioxidatative capacities of ethanol extracts from Acer tegmentosum Maxim (A. tegmentosum) stem in vitro. The extract at concentration of 200 ug/mL inhibited 10 and 20 ug/mL arsenic trioxide-induced cytotoxicity of HepG2 cells by 79.3 and 57.5%, respectively. The extract at concentration of 200 ug/mL inhibited 0.2 and 0.5 mM t-BHP-induced cytotoxicity of HepG2 cells by 66.3 and 35.7%, respectively. Antioxidative effects of the extract were examined via measurement of ABTS, superoxide, and peroxyl radical scavenging activities. ABTS radical scavenging activity of the extract was higher than that of ${\alpha}$-tocopherol. Superoxide scavenging activity of the extract was higher than that of catechin. Oxygen radical absorbance capacity of the extract was higher than that of ascorbic acid. Cupric reducing antioxidant capacity of the extract was higher than that of ${\alpha}$-tocopherol. The extract at concentrations of 100 and $500{\mu}g/mL$ inhibited 10 mM t-BHP-induced lipid peroxidation of HepG2 cells by 38.2 and 80.7%, respectively. The extract prevented supercoiled DNA strand breakage induced by hydroxyl or peroxyl radical. Total phenolic and flavonoid contents of the extract at concentration of $100{\mu}g/mL$ were 71.3 nmol/mL gallic acid and 18.8 nmol/mL catechin equivalents, respectively. Thus, strong cytoprotective and antioxidant effects of A. tegmentosum stem extract seem to be due to, at least in part, the prevention from free radicals-induced oxidation as well as high levels in polyphenolic contents.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.88-88
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• 2019

Antioxidants are involved in the defense mechanism against the attack of free radicals. This study was carried out to determine the antioxidant activity of new variety of Glycyrrhiza cultivar radix, Wongam and Sinwongam. Dissolved freeze dried Wongam and Sinwongam extracts were filtered by $0.2{\mu}m$ filter and serially diluted at the concentrations of $10{\mu}g/mL$, $50{\mu}g/mL$, $100{\mu}g/mL$, $500{\mu}g/mL$, and $1000{\mu}g/mL$. The antioxidant potential was determined by DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, ABTS (2,2-azino-bis (3-rthylbenzthiazoline-6-sulfonic acid) diammonium salt) radical cation decolorization assay, nitrite radical scavenging assay, and ferric reducing antioxidant power (FRAP) assay. DPPH radical scavenging activities (i.e. the highest value $50.9{\pm}0.8%$ by Wongam and $82.6{\pm}1.1%$ by Sinwongam), ABTS radical scavenging activities (i.e. the highest value $88.1{\pm}1.8%$ by Wongam and $98.6{\pm}0.1%$ by Sinwongam), and nitrite radical scavenging activities (i.e. the highest value $87.3{\pm}1.6%$ by Wongam and $89.8{\pm}0.8%$ by Sinwongam) increased in a dose-dependent manner. In addition, ferric reducing power activities also increased in a dose-dependent manner. The FRAP value of Wongam and Sinwongam extracts were $0.72{\pm}0.03$ and $0.99{\pm}0.06$ compared to ascorbic acid, as a positive control, was $1.32{\pm}0.02$. These results suggested that Wongam and Sinwongam have beneficial effects as a potent antioxidant.

• 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.

• Food Science and Preservation
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• v.14 no.6
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• pp.709-715
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• 2007

Korean green tea has been claimed to have health-promoting effects, which may be related to the antioxidant activity in vitro. Korean green teas (Woojeon, WJ ; Sejak, SJ ; Jungjak, JJ ; Daejak, DJ) were subjected to different harvested times and yet little research has examined their bioactive compounds. To assess the effect of this different harvested times on nutritional and health-related properties such as Korean green tea polyphenols, flavonoids, theanine and free amino acids, antioxidant activities and radical scavenging activities were determined. Total polyphenols in JJ (37.16 mg/g) was higher than in other products (WJ, 19.55 ; SJ 24.65 ; DJ, 23.28 mg/g). Contents of flavonol and flavone glycosides were the highest at DJ (350.83 mg%) as compared to WJ (220.81), SJ (256.88) and JJ (270.36 mg%). Contents of theanine and total free amino acids were the highest at WJ (14.11, 23.62 mg/g, respectively), but decreased thereafter. Antioxidant activities were higher in JJ and DJ, using the linoleic acid peroxidation, DPPH and ABTS free radical-scavenging activities. However, WJ and SJ had less active antioxidant activity and free radical-scavenging activity. Reducing powers were increased depend on the concentration of extracts. Antioxidant activity and free radical-scavenging activity of JJ and DJ seemed to relate with total polyphenol and flavonoid contents.