• Korean Journal of Pharmacognosy
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• v.33 no.3 s.130
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• pp.219-223
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• 2002

In order to screen new radical scavenging principle which is expected to be antiaging drug lead, we have isolated 160 strains of the marine-derived fungi and investigated 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity for their acetone extracts. The significant activities (>50% Inhibition) were observed in 8 strains of fungi (MFA006, MFA0l4, MFA040, MFA133, MFA139, MFA143, MFA148, MFA153), and among them, MFA153 (Aspergillus parasiticus) showed the most significant radical scavenging activity. The active components were purified by assay-guided isolation to yield two known benzyl alcohols, l53B3 (1) and l53B4 (2), and their structures were determined by physicochemical evidence. Two compounds (1,2) showed the significant radical scavenging activity with $IC_{50}$ values of 0.6 and $1.4{\mu}M$ against DPPH, respectively.

• Korean Journal of Food Science and Technology
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• v.48 no.3
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• pp.208-213
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• 2016

This study evaluated the in vitro radical scavenging and ${\alpha}$-glucosidase inhibitory activities of dried daraesoon (shoot of hardy kiwi) during cooking involving rehydration and subsequent heating at $180^{\circ}C$ with or without perilla oil. Pigments and antioxidants were quantified by HPLC and spectrophotometry. Unlike the tocopherol content, the polyphenol, flavonoid, chlorophyll, and carotenoid contents as well as the DPPH radical scavenging and ${\alpha}$-glucosidase inhibitory activities of daraesoon extract were significantly decreased by rehydration (p<0.05). Heating the rehydrated daraesoon for 10 or 20 min increased its radical scavenging activity irrespective of perilla oil addition, whereas the ${\alpha}$-glucosidase inhibitory activity increased significantly only after heating with perilla oil (p<0.05). During cooking, changes in both activities showed a similar pattern to that showed by polyphenol content changes. These results suggest that the health functionality of daraesoon can be enhanced by an appropriate cooking process that retains polyphenols.

• Journal of Microbiology and Biotechnology
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• v.20 no.6
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• pp.988-994
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• 2010

The EtOAc fraction of Lespedeza cyrtobotrya showed mushroom tyrosinase inhibitory and radical scavenging activities. Four active compounds were isolated based on Sephadex LH-20 chromatography and HPLC, and the structures were elucidated, on the basis of their LC-MS and NMR spectral data, as 2-(2,4-dihydroxyphenyl)-6-hydroxybenzofuran (1), eriodictyol-7-O-glucopyranoside (2), haginin A (3), and dalbergioidin (4), respectively. Compound (1) showed mushroom tyrosinase inhibitory activity with an $IC_{50}$ value of $5.2\;{\mu}M$ and acted as a competitive inhibitor. Furthermore, $37.3\;{\mu}M$ of compound 1 reduced 50% of the melanin content on human melanoma (MNT-1) cells. The radical scavenging activities of compounds 1, 2, 3, and 4 were shown to have $IC_{50}$ values of 11.0, 24.5, 9.0, and $36.5\;{\mu}M$, respectively, in an ABTS system and $IC_{50}$ values of 42.7, 36.0, 37.7, and $61.7\;{\mu}M$, respectively, in a DPPH system. The mushroom tyrosinase inhibitory activity of the EtOAc fraction of Lespedeza cyrtobotrya was contributed by compounds 1, 3, and 4, and its radical scavenging activity was contributed by compounds 1-4.

• ALGAE
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• v.28 no.4
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• pp.371-378
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• 2013

Water and methanolic extracts of Ecklonia cava, a marine brown alga, were prepared by ultrasonic extraction (UE) and conventional extraction (CE) methods. The radical-scavenging activity and the inhibitory effects against hydrogen peroxide ($H_2O_2$)-induced DNA damage of the extracts were investigated. All extracts prepared by CE exhibited higher total polyphenolic content than that in the extracts prepared by UE. Extraction yield and total phenolic content increased as the UE time increased. The radical-scavenging activities increased as the UE time increased. All extracts prepared by CE exhibited higher 1,1-diphenyl-2-pricrylhydrazyl (DPPH) and hydroxyl radical-scavenging activities than did those prepared by UE. Extracts prepared by UE showed stronger scavenging activities on alkyl radical and $H_2O_2$ than those prepared by CE did. Methanolic extract with UE 12 h (100MEU-12h) and methanolic extract with CE 24 h (100MEC-24h) were selected and evaluated by comet assay for their inhibitory effect against $H_2O_2$-induced DNA damage. 100MEU-12h showed slightly greater protective effect against $H_2O_2$-induced DNA damage than 100MEC-24h. Thus, UE can be effectively used as a seaweed extraction technique, and there is potential for scale-up of the extraction process.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.12
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• pp.1908-1914
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• 2013

In the present study, the levels of phenolic compounds and flavonoids, as well as activities of radical scavenging (DPPH and ABTS radical scavenging activity) and anti-obesity were assessed with cold water (CLC), hot water (CLH), and methanolic (CLM) extracts of Curcuma longa L. (turmeric). Our results showed that the phenolic compounds of CLC, CLH and CLM were $3.68{\pm}0.80%$, $3.94{\pm}0.74%$ and $9.01{\pm}0.73%$, respectively. The DPPH and ABTS radical scavenging activities of the CLM were significantly higher than that of the water extracts (CLC and CLH). During the adipocyte differentiation, the treatment of CLM more significantly inhibited lipid accumulation in 3T3-L1 cells than that of the water extracts. These results indicate that the stimulation of radical scavenging potential and the inhibition of adipogenesis were brought on by the lipophilic compounds of turmeric.

• 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 Marine Bioscience and Biotechnology
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• v.1 no.4
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• pp.252-259
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• 2006

Extracts which were prepared by four different extractions - 80% methanol extracts (ME) at high ($70^{\circ}C$) and a room temperature ($20^{\circ}C$), respectively and aqueous extracts (AE) at both temperatures with the residue after the methanol extracts - of 10 green, 19 brown and 25 red seaweeds collected in Jeju Island coast were examined for their DPPH free radical scavenging activity using a ESR (electron spin resonance) spectroscopy. A variety of the extracts showed positive scavenging effect against DPPH free radical (except the green seaweeds). Among the extracts, the brown seaweed extracts exhibited the highest scavenging activity. Especially, Sargassum spp. of the brown seaweeds have remarkable scavenging activities - both methanolic and aqueous at the both temperatures ($20^{\circ}C$ and $70^{\circ}C$). On the other hand, ME showed better scavenging activity than AE in the red seaweed extracts. These results indicate that autogenous seaweeds in Jeju will be potential natural antioxidants for functional food compounds.

• CELLMED
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• v.5 no.2
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• pp.14.1-14.6
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• 2015

Antioxidative and free radical scavenging properties of different stem extracts of Euphorbia trigona were evaluated and correlated with its total phenolic content. Aqueous, acetone and methanolic extracts of shade dried stem were obtained and were concentrated in vacuo. The antioxidant and free radical scavenging activities of stem extracts was determined by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging assay, reducing power assay, deoxyribose degradation assay and $Fe^{2+}$ chelating assay. Total phenolic contents (TPC) were evaluated using Folin-Ciocalteu reagent. The results confirmed that the plant is a rich source of polyphenolic compounds which are invariably higher compared to other herbs. All extracts showed TPC in the range of 146.6 - 168.6 mg/g gallic acid equivalents at $300{\mu}g/ml$ of extract. Among the three extracts ME showed highest scavenging activity as evidenced by maximum scavenging of DPPH (83.2%), $OH{\bullet}$ radicals (94.81%), $Fe^{2+}$ chelating activity (88.59%) and a high reducing power 0.623 at $300{\mu}g/ml$. Our results demonstrate that Euphorbia trigona, an unexplored xerophytic plant could be potential source of natural antioxidants and phytotherapeutic agents. The plant possess invariably high amount of polyphenolic compounds with a broad spectrum of antioxidant properties and could be further used for food, feed and pharmaceutical applications.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.123-130
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• 2005

Hydrogen-donating capacity, scavenging activity of reactive oxygen including superoxide anion radical and hydrogen peroxide, metal-chelating activity, and reducing power of garlic extracts were investigated. All tested garlic extracts exhibited in vitro antioxidant activities, with Uiseong extract showing highest hydrogen-donating and hydrogen peroxide-scavenging activities, and reducing power, followed by Seosan and Samchek extracts, in proportion to total thiosulfinate contents. Higher scavenging activity of superoxide anion radical was observed in Uiseong than Seosan and Samchek extracts. Metal-chelating activity increased in order of Uiseong < Seosan < Samchek, showing inverse relations to total thiosulfinate content. Garlic extracts of Uiseong and Seosan showed weak prooxidant activities and that of Samchek showed strong antioxidant activity against $Cu^{+2}$-induced human LDL oxidation. Protective effects on peroxyl and hydroxyl radical-induced DNA strand damages were observed in all tested garlic cloves. These results indicate growing conditions of garlic cloves affect total thiosulfinate content and antioxidant activities.

• Biomedical Science Letters
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• v.17 no.1
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• pp.69-77
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• 2011

In this study, we evaluated the protective effects of supercritical extracts and two step ethanol extracts after supercritical extraction from Schizandra chinensis on antioxidant activities and oxidative DNA and cell damages. Supercritical extracts removed DPPH (1,1-diphenyl-2-picryldrazyl) radical by 85.5% at 200 ${\mu}g$/ml, but showed low activities of scavenging and chelating the hydroxyl radical and ferrous iron. However, two step ethanol extracts showed low activities of scavenging the DPPH radical, but removed the hydroxyl radical by 86% at 200 ${\mu}g$/ml. In addition, we tested the activities of extracts for reducing hydroxyl radical-induced DNA and cell damage. Two step ethanol extracts showed protective effect against the oxidative DNA damage by reducing DNA segmentation, inhibiting DNA migration and decreasing the expression of phospho-H2AX. Also, two step ethanol extracts showed protective effect against the oxidative cell damage by inhibiting lipid peroxidation and increasing the expression of p21 protein. Taken together, we suggest that two step ethanol extracts from S. chinensis have a role as useful inhibitors against oxidative damages.