• Nutrition Research and Practice
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• v.11 no.3
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• pp.206-213
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• 2017

BACKGROUN/OBJECTIVES: Although studies have revealed that black garlic is a potent antioxidant, its antioxidant mechanism remains unclear. The objective of this study was to determine black garlic's antioxidant activities and possible antioxidant mechanisms related to nuclear factor erythroid 2-like factor 2 (Nrf2)-Keap1 complex. METHODS/MATERIALS: After four weeks of feeding rats with a normal fat diet (NF), a high-fat diet (HF), a high-fat diet with 0.5% black garlic extract (HF+BGE 0.5), a high-fat diet with 1.0% black garlic extract (HF+BGE 1.0), or a high-fat diet with 1.5% black garlic extract (HF+BGE 1.5), plasma concentrations of glucose, insulin,homeostatic model assessment of insulin resistance (HOMA-IR) were determined. As oxidative stress indices, plasma concentrations of thiobarbituric acid reactive substances (TBARS) and 8-isoprostaglandin $F2{\alpha}$ (8-iso-PGF) were determined. To measure antioxidant capacities, plasma total antioxidant capacity (TAC) and activities of antioxidant enzymes in plasma and liver were determined. The mRNA expression levels of antioxidant related proteins such as Nrf2, NAD(P)H: quinone-oxidoreductase-1 (NQO1), heme oxygenase-1 (HO-1), glutathione reductase (GR), and glutathione S-transferase alpha 2 (GSTA2) were examined. RESULTS: Plasma glucose level, plasma insulin level, and HOMA-IR in black garlic supplemented groups were significantly (P < 0.05) lower than those in the HF group without dose-dependent effect. Plasma TBARS concentration and TAC in the HF+BGE 1.5 group were significantly decreased compared to those of the HF group. The activities of catalase and glutathione peroxidase were significantly (P < 0.05) increased in the HF+BGE 1.0 and HF+BGE 1.5 groups compared to those of the HF group. The mRNA expression levels of hepatic Nrf2, NQO1, HO-1, and GSTA2 were significantly (P < 0.05) increased in the HF with BGE groups compared to those in the HF group. CONCLUSIONS: The improvements of blood glucose homeostasis and antioxidant systems in rats fed with black garlic extract were related to mRNA expression levels of Nrf2 related genes.

• Journal of Applied Biological Chemistry
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• v.60 no.4
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• pp.307-311
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• 2017

This study has been performed to identify the phenolic contents and antioxidant properties of methanol and ethanol extracts of young Camellia leaves in Jeju. Total polyphenol and flavonoid contents were 74.9 and 46.1 mg gallic acid equivalent/100 g, and 30.6 and 21.4 mg RE/100 g in the methanol and ethanol extracts, respectively. Based on $IC_{50}$ values, both extracts were also found to possess potent scavenging capacities of 1,1-diphenyl-2-picrylhydrazyl, nitric oxide and superoxide anion radicals, and ferrous ion chelating and reducing power activities. These results showed that young Camellia leaves is a good antioxidant source and holds promise as a natural ingredient in functional food and pharmaceutical supplement.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1298-1300
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• 2009

To develop a dietary beverage with functionalities of cheonggukjang, soymilk was fermented with Bacillus subtilis and its antioxidant activities were examined. Antioxidative capacities of fermented soymilk (FS) with 5 different B. subtilis were significantly different. Among these, FS with 2829PNU015 revealed the greatest antioxidant activities. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, total antioxidant activity, and low density lipoprotein (LDL) oxidation inhibition of FS with 2829PNU015 were increased by 150, 140, and 240%, respectively, compared with those of unfermented soymilk (p<0.05). Further study for the improvement of sensory properties of FS with B. subtilis is required for a commercial production.

• Korean Journal of Plant Resources
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• v.25 no.5
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• pp.568-577
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• 2012

The objective of this study was to investigate the antioxidative capacity of ethanol extracts from Rumex crispus L. The concentration of R. crispus L. extract at which DPPH radical scavenging activity was inhibited by 50% was 2.15 mg/mL, which was lower than that of ${\alpha}$-tocopherol (0.43 mg/mL), as compared to 100% by pyrogallol as a reference. Total antioxidant status was examined by total antioxidant capacity against ABTS radical reactions. Total antioxidant capacities of R. crispus L. extract at concentrations of 0.1 and 1 mg/mL were 0.47 and 2.33 mM Trolox equivalents, respectively, which were higher than those of ${\alpha}$-tocopherol. Superoxide scavenging activities of R. crispus L. extract at concentrations of 0.1 and 1 mg/mL were 21.5 and 78.9%, respectively, which were not significantly (p>0.05) different from those of catechin. Oxygen radical absorbance capacities of R. crispus L. extract at concentrations of 20 and 100 ${\mu}g/mL$ were 62.5 and 156.4 ${\mu}M$ Trolox equivalents, respectively, which were lower than those of ascorbic acid. Cupric reducing antioxidant capacities of R. crispus L. extract at concentrations of 0.1 and 1 mg/mL were 0.28 and 1.88 mM Trolox equivalents, which were similar or significantly (p<0.05) higher than those of ${\alpha}$-tocopherol, respectively. R. crispus L. extract prevented supercoiled DNA strand breakage induced by hydroxyl radical and peroxyl radical. Total phenolic contents of R. crispus L. extract at concentrations of 0.5 and 5 mg/mL were 0.58 and 3.85 mM gallic acid equivalents, respectively. R. crispus L. extract at concentration of 0.1 and 0.5 mg/mL inhibited 0.2 mM tert-butyl hydroperoxide-induced cytotoxicity by 38.5 and 63.5%, respectively, in HepG2 cell culture system. Thus, strong antioxidant and cytotoxicity-inhibiting effects of R. crispus L. extract seem to be due to, at least in part, the prevention from free radicals-induced oxidation as well as high levels in total phenolic contents.

• The Korean Journal of Food And Nutrition
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• v.27 no.3
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• pp.348-357
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• 2014

This study was carried out to evaluate the yield of extract, antioxidant compounds (total phenolic and total flavonoid), antioxidant (DPPH assay, ABTS assay and reducing power), and antimicrobial activities of bracken (Pteridium aquilinum Kuhn), according to cooking methods (non-blanched, blanched and seasoned). The yield of seasoned bracken extracts showed a high value of (4.59%) followed by non-blanched bracken and blanched bracken with 2.69% and 0.30%, respectively. In the total polyphenol and flavonoid contents, seasoned bracken extracts showed higher antioxidant compounds ($96.11{\pm}0.34mg\;GAE$/100 g RW, $20.90{\pm}0.mg\;CE$/100 g RW) than non-blanched and blanched. The total antioxidant activities (DPPH assay, ABTS assay and reducing power) were shown to be in the order of seasoned bracken > non-blanched bracken > blanched bracken. In the antimicrobial activities, non-blanched bracken extracts showed antimicrobial activity against B. cereus, B. subtilis, E. cloacae, E. coli, S. enterica, and P. aeruginosa except for S. aureus. The non-blanched bracken extracts (5 and 10 mg/disc) especially showed strong antimicrobial activity against P. aeruginosa ($10.00{\pm}0.71$ and $10.25{\pm}0.35mm$). The inhibition zone diameter from the extracts of blanched bracken and seasoned bracken was not detected. Many seasonings added in the process of cooking can increase the antioxidant capacities. The overall results of this study demonstrate that the cooked bracken with seasoning would be the most efficient way of ingesting antioxidant compounds.

• Food Science and Preservation
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• v.24 no.3
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• pp.406-412
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• 2017

In this study the physicochemical properties and antioxidant capacities of ginger (Zingiber officinale Rosc) Jungkwa with different kinds of sweeteners were determined. Jungkwa made with different sugars (sugar, xylitol, honey or oligosaccharides) were compared in aspect of physiochemical properties, antioxidant activities, total phenolic contents and sensory evaluation. Moisture contents Jungkwa treated different kinds of oligosaccarides showed highest value, in the order of honey, xylitol and sugar. $L^*$ value of Jungkwa treated with xylitol was the highest, $a^*$ value of Jungkwa treated with honey, sugar JungKwa were higher then others. Free sugar contents of Jungkwa treated with sugar showed the highest value in sucrose, glucose and galactose. Jungkwa with xylitol showed lowest value in all free sugar contents. Hardness and chewiness of Jungkwa treated with xylitol showed the highest value. The antioxidant activity measured by DPPH and ABTS radical scavenging activity and total penolic content were the highest in Jungkwa treated with honey, followed by Jungkwa treated with xylitol, oligosaccharides and sugar. Appearance and color of oligosaccarides and honey treated Jungkwa were preferred. In ginger taste, sweetness, chewiness were highest in sugar treated Jungkwa (not significant difference in treatments). As a result, honey treated Jungkwa has higher antioxidant activity and quality than other sugar treatments.

• The Korea Journal of Herbology
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• v.33 no.4
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• pp.95-100
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• 2018

Objectives : Ligustri Fructus has been used since ancient times as a medicinal usages in folk medicines against antitumor purpose. Many biological active constituents have been identified from this biomass such as several terpenoids and lignans. In current study, the properties of antioxidant and anti-diabetic complications using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)($ABTS^+$) radicals scavenging, and advanced glycation end products (AGEs) inhibition assays were evaluated by different extraction methods of Ligustri Fructus. Methods : In present continuing research for development of bioactive natural ingredients, antioxidant and AGEs formation inhibitory capacities of Ligustri Fructus extracts using different organic solvents were prepared and the biological potentials were investigated using in vitro bioassays. Antioxidant properties were evaluated employing radical scavenging assays using DPPH and $ABTS^+$ radicals. In addition, the anti-diabetic complications effects of Ligustri Fructus extracts were tested via AGEs formation inhibitory assay. The total phenolic contents were determined using a spectrophotometric method. Results : All the tested extracts exhibited dose-dependent radical scavenging and AGEs formation inhibitory activities. Among the tested samples, hot water extract of Ligustri Fructus was showed the most potent activity with $IC_{50}$ value of $494.8{\pm}6.7{\mu}g/m{\ell}$ against DPPH radical scavenging assay. Also, $ABTS^+$ radical scavenging activity of hot water extract was higher than those of other extracts. In addition, AGEs formation inhibitory effects of each extacts and total phenolic contents were evaluated. Conclusions : These results suggested that Ligustri Fructus can be considered as a new effective source of natural antioxidant and anti-diabetic complications resources.

• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.235-239
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• 2017

The objective of the present study was to evaluate in vitro antioxidant activity, antioxidant content and pancreatic lipase inhibitory activities of Makgeolli supplemented with 0, 1, 2, and 4% (w/v) Jeju camellia mistletoe during fermentation. Total phenolic and flavonoid contents tended to increase as content of Jeju camellia mistletoe increased. Supplementation with Jeju camellia mistletoe resulted in a significant increase in the scavenging capacities of 1,1-diphenyl-2-picrylhydrazyl, hydrogen peroxide, nitric oxide and superoxide anion radicals, and reducing power activity. Moreover, pancreatic lipase inhibitory activity was significantly elevated by Jeju camellia mistletoe addition. These results suggest that Jeju camellia mistletoe is considered to be a good material to improve antioxidant and pancreatic lipase inhibitory activities of makgeolli.

• Preventive Nutrition and Food Science
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• v.19 no.1
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• pp.40-48
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• 2014

Laver is one of the most consumed edible red algae seaweeds in the genus Porphyra. Laver is primarily prepared in the form of dried, roasted, and seasoned products. We investigated the total polyphenol and flavonoid contents of laver products, and evaluated the in vitro antioxidant properties of solvent extracts from commercially processed laver products. Significant differences in the concentration of phenolic compounds were found among differently processed laver. The total phenolic content for laver extracts ranged from 10.81 mg gallic acid equivalent (GAE)/g extract to 32.14 mg GAE/g extract, depending on extraction solvent and temperature. Laver extracts contained very few flavonoids (0.55 mg catechin equivalent/g extracts to 1.75 mg catechin equivalent/g extracts). 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), hydroxyl radical, and superoxide anion scavenging assays were used to determine the radical scavenging capacities of laver extracts. These assays revealed that the processing method and extraction condition affected the antioxidant potentials of laver. Antioxidant activity of dried laver, roasted laver, and seasoned laver increased in a concentration-dependent manner ($100{\sim}1,000{\mu}g/mL$). The radical scavenging activities of $37^{\circ}C$ and $100^{\circ}C$ water extracts were lower than that of a $37^{\circ}C$ 70% ethanol extract. The highest radical scavenging capacity was observed in the $37^{\circ}C$ 70% ethanol extracts of dried laver, roasted laver, and seasoned laver. Overall, these results support that notion that laver contains bioactive compounds, such as polyphenols and flavonoids, which may have a positive effect on health.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.2
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• pp.189-195
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• 2013

This study was designed to analyze the effects of methanol extracts and solvent fractions of the young branch of Prunus persica on scavenging activity of ROS, RNS and inhibiting activity of oxidative modification in human LDL induced by copper ion or free radical generator. The scavenging capacities of the fractions on DPPH radical, superoxide radical, nitric oxide and peroxynitrite were exhibited the highest in ethylacetate fraction, followed by butanol fraction. In the copper-induced LDL oxidative modification system, the highest antioxidant activity was revealed in ethylacetate fraction, and butanol fraction exhibited a similar activity. However, solvent fractions of the young branch of Prunus persica showed a relatively low antioxidant activity in the AAPH-mediated LDL oxidation. In addition, ethylacetate and butanol fractions also inhibited the copper-mediated LDL oxidation in the REM assay, which was comparable to that of the positive controls, including EDTA, ascorbic acid and BHT. Futhermore, a content of total phenolics in these two fractions was higher than that of the other fractions. These results indicated that ethylacetate and butanol fractions of the young branch of Prunus persica were useful for the prevention of the free radical- or metal ion-induced oxidative damages.