• Toxicological Research
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• v.17
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• pp.271-280
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• 2001

We report on the applicability oj a method recently developed in our laboratory for measuring the antioxidant potential of isolated chemicals and extracts derived from natural products. Peroxyl radicals generated by thermal homolysis of 2,2'-azobis-amidinopropane (ABAP) oxidize $\alpha$-keto-${\gamma}$-methiolbutyric acid (KMBA) to ethylene, which is monitored by gas chromatography. Inhibition of ethylene formation in the presence of antioxidants that compete with KMBA for peroxyl radicals is the basis of the Total Oxyradical Scavenging Capacity Assay (TOSCA; Winston et al., 1998). Antioxidative activities of water-soluble extracts of American green tea, the anti-hepatotoxic flavonolignan from milk thistle (Silybum marianum) silybin, Ginkgo biloba extract EGb 761, and a series of naturally occuring sesquiterpene lactones (all ger-macranolides found in in fungi, liverworts, and plants) were studied. The specific TOSC value per $\mu$M silybin was 5.2, which is essentially comparable to that of Trolo $x^{ⓡ}$, a water-soluble vitamine E analog. Tea and Ginkgo extracts exhibited potent peroxyl radical scavenging capacity with values, respectively of =1700 and 1000 $\mu$mols Trolo $x^{ⓡ}$ equivalent per gram dry matter. The known anti-inflammatory activity of some germacranolides prompted study of their antioxidant capacity. None of the lactones exhibited antioxidant capacity toward peroxyl radicals comparable to Trolo $x^{ⓡ}$; costunilide, the most lipophilic, had a TOSC value = to glutathione. The potential role of peroxyl radicals in lipidperoxidation, other cellular damage, and var-ious disease states suggest a possible preventive role for silybin, green tea and Ginkgo biloba in oxidative stress caused by these free radical species.ecies.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.5
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• pp.501-507
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• 2004

Some selected fruit juices and fermented red grape juices were investigated to determine the phenolic components by the Folin-Ciocalteu method and antioxidant capacity using α, α-diphenyl-β-picrylhydrazyl(DPPH) method. Commercial red grape beverages and red wines were also analyzed as control groups. In the juice, kiwi fruit had the highest phenolic components followed by orange(summer), red grape(Cambell Early:Yonng-Chun), mandarin orange(autumn), apple(Hong-Ok), cherry tomato, tomato and water melon. Whereas, on the antioxidant efficiency, tomato showed the highest free radical scavenging effect followed by orange(summer), cherry tomato, mandarin orange(autumn), apple(Aori) red grape(Cambell Early:Sung-Ju), kiwi fruit and water melon. The amount of pheonlic components of red wine was 2 times of that of fermented sugar added grape juice, however, the antioxidant efficiency of fermented sugar added grape juice was almost the same as that of red wine. It was found that no clear relationship could be shown between the content of phenolic component and antioxidant capacity of fruit juices and fermented red grape juices. The fruit juices from tomato, orange, cherry tomato, mandarin orange, red grape and fermented sugar added red grape juice showed high free radical scavenging effect and should be regarded as a valuable source of antioxidant.

• Food Science and Biotechnology
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• v.15 no.2
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• pp.312-316
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• 2006

Crude extract of young dangyuja (Citrus grandis Osbeck) fruit was investigated for its antioxidant activity as measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. Among the samples, including 4 Citrus species and various solvent-extracted-fractions of young dangyuja fruit, the water-extracted fraction (WF) and butanol-extracted fraction (BF) showed the greatest DPPH free radical scavenging activity. WF and BF were further examined for their antioxidant activities by three different in vitro assays. The cell viability tests using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay showed that both fractions significantly reduced $H_2O_2$-induced cytotoxicity in HepG2 cells dose-dependently. Generation of the reactive oxygen species (ROS) was also reduced in cells pretreated with both fractions. In addition, BF showed a higher level of lipid peroxidation inhibitory capacity than WF in $H_2O_2$-treated HepG2 cells. Taken together, these results indicate that young dangyuja fruit can be used as an easily accessible source of natural antioxidants.

• YAKHAK HOEJI
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• v.49 no.1
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• pp.86-91
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• 2005

Flavonoids are class of polyphenolic compounds widely distributed in the plant kingdom, which display a variety of biological activities, including antiviral, antithrombotic, antiinflammatory, antihistaminic, antioxidant and free-radica 1 scavenging abilities. The antioxidant enzyme (AOE) system plays an important role in the defense against oxidative stress insults. To determine whether flavonoid, myricetin can exert antioxidative effects not only directly by modulating the AOE system but also scavenging free radical, we investigated the influence of the flavonoid myricetin on cell viability, different antioxidant enzyme activities, ROS level and the expression of different antioxidant emzyme in B16F10 murine melanoma cells. Myricetin in a concentration range from 6.25 to $50\;{\mu}M$ decreased superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzyme activities, but catalase (CAT) activity was increased. In the myricetin-treated group, ROS levels were decreased dose-dependently. Antioxidant enzyme expression was measured by RT-PCR. Myricetin treatment of B16F10 cells increased catalase expression. Expression levels of copper zinc superoxide dismutase (CuZn SOD) were not affected by exposure of myricetin. Manganese superoxide dismutase (Mn SOD) and GPx expression levels decreased slightly after myricetin treatment. In conclusion, the antioxidant capacity of myricetin was due to CAT and free-radical scavenging.

• Ocean and Polar Research
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• v.26 no.1
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• pp.59-64
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• 2004

As a part of our search for novel antioxidants from the seaweeds, we have investigated radical scavenging effect for their crude extracts using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, authentic peroxynitrite, and 3-morpholinsydnonimine (SIN-1), a peroxynitrite-generating species in vitro. Thirty-four seaweeds were screened for $ONOO^-$ and DPPH radical scavenging activities. A potent inhibitory effect against peroxynitrite generated by SIN-1 at $5{\mu}g/ml$ of methanol extracts was observed in order of Ishige okamurae(95.3%), Sargassum hemiphyllum(90.2%), Symphyocladia latiuscula(89.6%), Porphyra suborbiculata(86.7%), and Gelidium amamsii(85.9%), Also, a significant scavenging effect against direct authentic peroxynitrite was revekaled for methanol extracts of Ishige okamurae(66.2%) and Sargassum hemiphyllum(55.2%) and the acetone/methylene chloride(1:1) extract of Gigatina tenella (61.0%). In our measurement for evaluating the capacity to scavenge the stable free radical of DPPH, acetone/methylene chloride(1:1) extracts of Symphyocladia latiuscula, Gloiopeltis furcata, and Sargassum thunbergii and the methanol extract of Sargassum sp. showed an inhibitory potency of 85.8%, 82.8%, 74.1%, and 64.0%, respectively.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.1
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• pp.115-121
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• 2011

This study was performed to investigate the antioxidant activity of extracts of black Panax ginseng (BGE) and its crude saponin (BGECS). The antioxidant activities of BGE and BGECS were evaluated for free radical scavenging activity against stable free radical (1,1-diphenyl-2-picrylhydrazyl) DPPH, nitrite, hydrogen peroxide and superoxide. In addition, the antioxidant activity of BGE and BGECS against peroxyl radicals, hydroxyl radicals and peroxynitrites were determined by the total oxy-radical scavenging capacity (TOSC) assay. As a result, BGE and BGECS were found to have a strong inhibitory activity with >90% against the DPPH radical at $1000{\mu}g/m{\ell}$ concentrations. Also, BGE and BGECS exhibited strong inhibitory activity with >80% against hydrogen peroxide at lower concentration ($125{\mu}g/m{\ell}$). Moreover, specific TOSC values (405 and 473 TOSC/mM) of BGE and BGECS against peroxynitrites were higher than GSH (347 TOSC/mM) used a positive control. These results suggest that BGE and BGECS could be useful to develop functional foods against disease related oxidative stress.

• Archives of Pharmacal Research
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• v.27 no.6
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• pp.610-614
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• 2004

The in vitro antioxidant properties of some flavone-6(4)-carboxaldehyde oxime ether deriva-tives (Ia-f, lIa-f） were determined by their effects on the rat liver microsomal NADPH-dependent lipid peroxidation (LP） levels by measuring the formation of 2-thiobarbituric acid reactive substances. The free radical scavenging properties of the compounds were also examined in vitro by determining their capacity to scavenge superoxide anions and interact with the stable free radical 2, 2-diphenyl-1-picrylhydrazyl (DPPH). The most active compounds, lib (Flavone-4＇-carboxaldehyde-O-ethyl oxime） and Id (Flavone-6-carboxaldehyde-O-［2-(1-pyrolidino） ethyl］ oxime）, caused 98 and 79％ inhibition of superoxide anion production and DPPH stable free radical at $10^{-3}{\;}M$, respectively.

• Journal of Korean Medicine Rehabilitation
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• v.31 no.1
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• pp.95-108
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• 2021

Objectives This study was conducted to investigate the beta-glucan, ginsenoside content, antioxidant activity and safety of modified Kyungohkgo added to Sparassis crispa and Hericium erinaceum. Methods The marker compounds contents, antioxidant activity and safety of modified Kyungohkgo were tested. The contents of beta-glucan and ginsenoside Rb1, Rg1, and Rg3 marker compounds were measured, the antioxidant activity was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, and a safety test was conducted via single dose toxicity assessment. Results Analyzing the contents of marker compounds showed 351.75 mg/g of beta-glucan, 0.0327 mg/g of ginsenoside Rb1 and 0.0802 mg/g of ginsenosai Rg3. In the DPPH free radical scavenging activity, the inhibition concentration 50% of modified Kyungohkgo was 0.2880%. The scavenging activity of modified Kyungohkgo was 5.49% activity at 0.05% concentration, 89.66% activity at 0.5% concentration, 94.68% activity at 1% concentration, and 96.06% activity at 5% concentration. In the single dose toxicity test of modified Kyungohkgo, a dose of 2,000 mg/kg B.W. was set at its highest capacity and observed after oral administration to female and male rats. No toxicological findings were recognized. It was observed that the resulting lethal dose can be set to 2,000 mg/kg B.W. or higher for both females and males. Conclusions The results of the experiment on modified Kyungohkgo showed that the marker compounds contents were beta-glucan and ginsenoside Rb1 and Rg3, that antioxidant activity was observed through the DPPH free radical scavenging activity, and safety was confirmed through the single dose toxicity assessment.

• Journal of Korean Medicine Rehabilitation
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• v.32 no.2
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• pp.1-17
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• 2022

Objectives This study was conducted to investigate the beta-glucan & ginsenoside content, antioxidant activity, anti-inflammatory effect and safety of herbal medicine mix. Methods The marker compounds contents, antioxidant activity and safety of herbal medicine mix were tested. The contents of beta-glucan and ginsenoside Rg3 were measured, the antioxidant activity was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, anti-inflammatory and a safety test was conducted via single dose toxicity assessment. Results Analyzing the contents of marker compounds showed 362.3 mg/g of beta-glucan, and 0.4184 mg/g of ginsenoside Rg3. In the DPPH free radical scavenging activity, the IC50 of herbal medicine mix, was 0.146%. The scavenging activity of herbal medicine mix was 88.28% activity at 0.5% concentration, and 90.61% activity at 5% concentration. In the lipopolysaccharides (LPS) anti-inflammatory test, the herbal remix showed a significant decrease in tumor necrosis factor-alpha (TNF-𝛼) and interleukin-6 (IL-6) compared to the LPS-induced group. In the single dose toxicity test of herbal medicine mix, a dose of 2,000 mg/kg body weight (BW) was set at its highest capacity and observed after oral administration to female and male rats. No toxicological findings were recognized. It was observed that the resulting lethal dose can be set to 2,000 mg/kg BW or higher for both females and males. Conclusions The results of the experiment on herbal medicine mix showed that the marker compounds contents were beta-glucan and ginsenoside Rg3, that antioxidant activity was observed through the DPPH free radical scavenging activity, anti-inflammatory effect was observed through TNF-𝛼 and IL-6 measurement, and safety was confirmed through the single dose toxicity assessment.

• Korean Journal of Medicinal Crop Science
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• v.27 no.4
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• pp.259-270
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• 2019

Background: Eucommia ulmoides has long been used as an herbal medicine for the treatment of diabetes, hypertension and other diseases in many Asian countries. Methods and Results: This study aimed at evaluating the antioxidant and anti-inflammatory properties of its water (EU-DW, and REU-DW) and ethanol (EU-EtOH, and REU-EtOH) extracts, as well as those of non-roasted E. ulmoides (EU) and roasted EU (REU) cortex. The following were assessed in each extract: total phenolic and flavonoid contents, 1,1-diphenyl-2-picryl-hydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and nitrite radical scavenging activities, reducing power, DNA damage prevention activity, and nitric oxide (NO) inhibition activity. Both EU and REU extracts showed high phenolic and flavonoid content, dose-dependent DPPH radical scavenging capacity, high reducing activity, and considerable DNA damage prevention activity. EU extracts showed remarkable ABTS free radicals scavenging capacity. REU extracts showed a higher radical scavenging capacity and played an important role in inhibiting NO production. Conclusions: The results of this study suggested that aqueous and ethanol extracts of EU and REU possess antioxidant capacities, and prevent oxidative damage to DNA, probably owing to their phenolic and flavonoid content. Therefore, EU and REU could be candidates antioxidant supplements.