• The Journal of Korean Medicine
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• v.26 no.3 s.63
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• pp.204-214
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• 2005

Objectives : The verity extract of the Gagam-Hyungbang-Gihwang-tang (GHG) was assessed to determine the mechanisms of its antioxidant activity. Methods : The fellowing effects were measured : GHG exhibited a concentration-treatment; scavenging ${\alpha},\;{\alpha}-diphenyl-\beta-picrylhydrazyl$ (DPPH) radical, linoleic acid oxidation in a thiocyanate assay system, and superoxide anion, hydroxyl radical-induced DNA nicking. We investigated mRNA levels such as superoxide-dismutase. Results : The GHG extract showed dose-dependent free radical scavenging activity, including DPPH radicals, hydroxyl radicals, and superoxide anion, using different systems. The GHG was also found to be effective in protecting plasmid DNA against the strand breakage induced by hydroxyl radicals in Fenton's reaction mixture. Furthermore, SOD-1 mRNA expression levels increased in tat hepatoma H4IIE cells Conclusions : We expect that GHG will to helpful to the development of antioxidant activity treatments.

• Journal of Life Science
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• v.26 no.9
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• pp.1022-1026
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• 2016

In this study the hot water extract was prepared from Hydrocotyle sibthorpioides (Araliaceae) leaves and stems to study antioxidant activities and lipoxygenase inhibition. The extract showed the protective hydroxyl radical (-OH) which can damage virtually all types of macromolecules: carbohydrates, nucleic acids (mutations), lipids (lipid peroxidation), and amino acids. Hydroxyl radical scavenging activity of H. sibthorpioides was 78.6%. The extract showed strong activity against 1, 1- diphenyl 2-picrylhyorazyl (DPPH) which is a well-known radical and a trap (scavenger) for other radicals. DPPH scavenging activity of leaves of H. sibthorpioides was evaluated at 8.0 mg/ml was 86.0%. Lipoxygenases (LOXs) constitute a heterogeneous family of lipid peroxidizing enzymes capable of oxygenating polyunsaturated fatty acids to their corresponding hydroperoxy derivatives. The inhibitory effect of 15-LOX by H. sibthorpioides was assayed using a Morgan microplate assay. The extract of H. sibthorpioides was 55.5% inhibitory effects on the inhibition of LOX at 8.0 mg/ml. The IC₅₀ values for OH activity, DPPH activity, and LOX inhibition from leaves 5.23 mg/ml, 6.44 mg/ml, and 3.71 mg/ml, respectively. Antioxidative activity assay showed that the water extracts from leaf and stem had a strong reducing power. These results show that H. sibthorpioides has some phytochemical constituents which may be active against the free radicals (OH and DPPH) and lipoxygenase enzyme.

• FLOWER RESEARCH JOURNAL
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• v.17 no.3
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• pp.158-164
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• 2009

Present studies were conducted to investigate the effects of water and 80% ethanol solvent on antioxidant activities of flower extracts of Chrysanthemum frutescens, Coreopsis lanceolata, Matricaria recutica, and Hieracium pilosella. Extraction yields of water extracts ranged 27.15~40.25% and 80% ethanol extracts 24.92~42.84%, respectively. In all species polyphenol and flavonoid contents were higher with 80% ethanol extraction, especially in C. lanceolata. Same results were obtained with scavenging effects on DPPH and ABTS radicals and ferrous ion chelating effects. Scavenging activity of flower extracts on DPPH radicals was highest in H pilosella - higher than that of synthetic antioxidant DHT. Higher scavenging activity on ABTS radicals was observed with M. recutica. Generally Compositae flower extracts exhibited higher scavenging activity on ABTS radicals than DPPH. Scavenging activity on ABTS radicals of M. recutica and P pilosella were superior to those of ascorbic acid and BHT. Ferrous ion chelating effects were much higher with H. pilosella flower extracts by 80% ethanol. Chelating effects of 4 species were much lower than those of EDTA. In conclusion, to develop natural antioxidant from above 4 Compositae species, 80% ethanol is recommended for efficient solvent to obtain maximum antioxidant isolation and activity.

• Korean Journal of Plant Resources
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• v.23 no.1
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• pp.38-46
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• 2010

Phenolic compound contents and scavenging activity on DPPH and ABTS radicals in twelve fern species were studied by analysing ultrasonification extraction of dried aerial parts and rhizomes using methanol solvent. Total polyphenol content ranged from 2.97 to 140.1 mg per 1 g dried sample and 0.80 to $49.58\;mg{\cdot}g^{-1}$ fresh sample. Highest polyphenol content was obtained with aerial part of Davallia mariesii and Polystichum lepidocaulon. Total flavonoid content of dried sample was $2.56{\sim}34.91\;mg{\cdot}g^{-1}$ and fresh sample $0.71{\sim}11.49\;mg{\cdot}g^{-1}$. Higher flavonoids were obtained with dried aerial part of Dryopteris crassirhizoma, but with fresh aerial part of P. lepidocaulon. In general, total polyphenol content was higher in rhizomes, except in case of total flavonoid. Scavenging effects on DPPH and ABTS radicals was higher with rhizome extracts compared to aerial parts. The rhizome of Polystichum polyblepharum showed highest effects on both radicals. However, the amount of fresh sample for $RC_{50}$ with consideration of water content and extraction yield. P. lepidocaulon aerial part was more advantageous than P. polyblepharum rhizome. All the fern extracts except for the Coniogramme japonica extract demonstrated superior scavenging effects on ABTS radicals, being similar activity of ascorbic acid and BHT.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.381.3-382
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• 2002

Free radical-mediated cell damage and free radical attack on polyunsaturated fatty acids result in the formation of lipid radicals. These lipid radicals react readily with molecular oxygen to produce peroxy radicals responsible for initiating lipid peroxidation. The peroxidation of cellular membrane lipid can lead to cell necrosis and considered to be implicated in a number of pathophysiological conditions as well as in the toxicity of many xenobiotics. DPPH is known to abstract labile hydrogen and the ability to scavenge the DPPH radical is related to the inhibition of lipid peroxidation. (omitted)

• Biomedical Science Letters
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• v.14 no.3
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• pp.193-198
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• 2008

In order to evaluate on the effect of kaempferol on the cytotoxicity of oxygen tree radicals, XTT assay was performed to determine the cell viability after skin fibroblasts derived from human (Detroit 51) that were treated with various concentrations of hydrogen peroxide $(H_2O_2)$. And also, the effect of kaempferol on the cytotoxicity induced by H202 that was examined by cell viability, lactate dehydrogenase (LDH) activity and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity in these cultures. $H_2O_2$ decreased cell viability in dose-dependent manner in these cultures and the $XTT_{90}\;and\;XTT_{50}$ values were determined at concentration of $35{\mu}M\;and\;90{\mu}M$ of $H_2O_2$ after skin fibroblasts derived from human were treated with $15{\sim}90{\mu}M$ of $H_2O_2$ for 6 hours, respectively. $H_2O_2$ was highly toxic on cultured skin fibroblasts derived from human by toxic criteria of Brenfreund and Puerner (1984). In the protective effect of kaempferol on $H_2O_2$-induced cytotoxicity, kaempferol increased DPPH radical scavenging activity and significantly decreased LDH activity. From these results, it is suggested that oxygen tree radical, $H_2O_2$, was highly toxic on cultured skin fibroblasts derived from human, and also kaempferol of flavonoid showed the protection on $H_2O_2$-induced cytotoxicity.

• Preventive Nutrition and Food Science
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• v.4 no.2
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• pp.92-96
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• 1999

The effects of aqueous extracts from Korean commercial teas on excessive free radicals were examined utilizing spin trapping, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical and lipid peroxidation. A potent scavenging effect of green tea and oriental senna tea was dound using sipin trapping. The most effective teasagainst the DPPH radical was green tea, followed inorder by pine leak tea, Chinese gutta percha tea and orietnal senna tea. Similar to the effects of DPPH radical , green tea, pine leaf tea, Chinese gutta percha tea and oriential senna tea had an inhibitory effect on lipid peroxidation. These findings predict that Korean tea is a promising material for scavenging free radicals, and for curing diseases related to free-radical reactions.

• Biomedical Science Letters
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• v.28 no.4
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• pp.307-311
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• 2022

The extract of EA lacks studies showing its efficacy other than that it contains caffeic acid, an active compound that has antioxidant and neuroprotective effects on nerve cells. Therefore, in this study, we attempted to determine the effectiveness of EA extraction. In this study, we performed a DPPH assay to determine the antioxidant potential of EA. And then, the cytotoxic concentration of EA in HaCaT keratinocytes was determined, and the antioxidant effect was determined by measuring the malondialdehyde (MDA). The results of DPPH, a chemical antioxidant assay, clearly demonstrated the antioxidant capacity of EA extracted with distilled water. In addition, cell-based assays provide useful information on the protective effect of EA on oxidative stress-induced apoptosis.

• Preventive Nutrition and Food Science
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• v.19 no.1
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• pp.34-39
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• 2014

This study evaluated the influence of cooking methods (blanching, pan-frying, and microwaving) on the antioxidant activity of Ligularia fischeri (LF) using myoglobin methods against five different reactive oxygen species (ROS) (i.e., 2,2-diphenyl-1-picrylhydrazyl (DPPH), hypochlorite ions, hydroxyl radicals, peroxyl radicals, and peroxynitrite ions). With respect to DPPH scavenging activity, the antioxidant activities of blanched LF and pan-fried LF were significantly higher (P<0.05) than that of fresh LF for all cooking times. Pan-fried LF and microwaved LF showed higher antioxidant activities against hydroxyl radicals and peroxyl radicals than uncooked LF, while the protective effect of blanched LF was low, except for the at the 3 min cooking time point. Microwaved LF showed high antioxidant activity against all ROS at the 2 min cooking time point. Interestingly, LF that had been microwaved for 2 min and 3 min had high antioxidant values, whereas blanched LF and pan-fried LF had low antioxidant values. The activities of cooked LF against five different ROS were characterized comprehensively by 5-axe cobweb charts.

• Journal of Applied Biological Chemistry
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• v.65 no.3
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• pp.221-230
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• 2022

We investigated the antioxidant and anti-inflammatory effects of silymarin. The antioxidant activity was evaluated using 1,1-diphenyl-1-picrylhydrazyl radical (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals scavenging assays. Silymarin scavenged 71% of DPPH radicals and 78% of ABTS radicals at a concentration of 1 mg/mL, respectively. Silymarin effectively inhibited the oxidative damage of DNA, and the oxidative modifications of human serum proteins and Cu,Zn-SOD. Also silymarin effectively inhibited H₂O₂- and LPS-induced cell death as well as the generation of reactive oxygen species and DNA fragmentation by H₂O₂ and LPS. The results suggested that silymarin might be an effective natural antioxidant and anti-inflammatory material.