• Natural Product Sciences
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• 제9권2호
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• pp.80-82
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• 2003

Since reactive oxygen radicals play an important role in carcinogenesis and other human diseases including neurodegenerative states, antioxidants present in natural products have received considerable attention for alleviation of these disease states. Therefore, in order io identify antioxidants in plant extracts, fifty-seven methanolic extracts derided from indigenous Korean plants were primarily assessed for potential to scavenge stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. As a result, nine plant extracts were found to exhibit the DPPH free radical scavenging activity in the criteria of $IC_{50}<40\;{\mu}g/ml$. In particular, the extracts of Melioma oldhami $(IC_{50}=0.1\;{\mu}g/ml)$, Myrica rubra $(IC_{50}=16.2\;{\mu}g/ml)$, Sympolocos paniculata $(IC_{50}=23.0\;{\mu}g/ml)$, Carpinus laxiflora $(IC_{50}=25.1\;{\mu}g/ml)$, and Cleyera japonica $(IC_{50}=26.2\;{\mu}g/ml)$ showed a potent radical scavenging activity. Further study for the identification of active compounds from these lead extracts might be warranted.

• 한국식품저장유통학회지
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• 제21권4호
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• pp.593-599
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• 2014

항산화 및 항균활성을 가진 천연물을 활용해 합성보존료를 대체하고자 하는 연구가 활발한 가운데 국내 자생 식물 중 135종을 대상으로 DPPH radical 소거활성을 측정하였다. 이중 항산화 활성이 10%대로 낮게 나타난 식물 8종에 대해 항균효과를 조사하였다. 식물 추출물의 DPPH radical 소거활성은 0.41~94.84%로 다양하였으며, 가장 효과가 좋은 식물은 꽃향유와 우엉으로 각각 94.84, 80.55%를 나타내었다. 우엉은 잎의 경우 26.87, 뿌리 19.29%의 활성을 나타내 동일 식물이라도 추출부위에 따라 활성의 차이가 있을 것으로 보인다. 선이질풀과 비쭈기나무는 각각 그람양성균인 B. subtilis, 그람음성균인 E. coli 및 Candida속인 C. albicans에 대해 2.2~10.8 mm 수준의 항균활성을 나타내었다. 각 식물에 대한 다양한 추출법을 적용하여 기능성을 확인하고 이들 항산화성 물질에 대한 추가 연구가 진행되어야 할 것으로 사료된다.

• Journal of the Korean Wood Science and Technology
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• 제31권6호
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• pp.40-44
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• 2003

This study was carried out to investigate the antioxidant activities of domestic trees grown in Korea. Based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity method, the methanolic extracts of 23 species were screened in order to search for natural antioxidants. Among these species, Acer ginnala, Cotinus coggygria, Acanthopanax koreanum, Thea sinensis and Pinus densiflora showed stronger antioxidative activity comparing with reference compound, ascorbic acid.

• ALGAE
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• 제18권4호
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• pp.341-347
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• 2003

The potential antioxidative activity of water-soluble enzymatic hydrolyzates from a kelp, Ecklonia cava was evaluated by free radical scavenging and lipid peroxidation assays. To prepare water-soluble hydrolyzates from E. cava the seaweed was enzymatically hydrolyzed by five carbohydrases (Viscozyme, Celluclast, AMG, Termamyl and Ultraflo) and five proteases (Protamex, Kojizyme, Neutrase, Flavourzyme and Alcalase). Among all the hydrolyzates, Celluclast hydrolyzate effectively scavenged free radicals released from DPPH (1,1-diphenyl-2- pricrylhydrazyl) and recorded around 73% scavenging activity at the concentration of 4 mg ${\cdot}ml^{-1}$. This hydrolyzate was thermally stable and DPPH radical scavenging activity remained 80% or higher at heating temperatures of 40 and 60$^{\circ}C$ up to 12 h and around 80% at 100$^{\circ}C$ up to 8 h. AMG and Ultraflo hydrolyzate inhibited the lipid peroxidation of fish oil as that of $\alpha$-tocopherol. These results suggested that an enzymatic extraction will be an effective way for the production of a potential antioxidant from seaweeds.

• Preventive Nutrition and Food Science
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• 제14권4호
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• pp.277-282
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• 2009

The antioxidant potency of methanolic extract of Duchesnea indica (MDI; Indian strawberry) was investigated by employing various established in vitro systems, such as total phenolic content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, reducing power assay, metal chelating assay, superoxide radical scavenging activity and protective ability of DNA damage and protein oxidation. MDI inhibited metal chelating by 75.57% at 2 mg/mL, scavenged 50% DPPH free radical at 29.13 ${\mu}$g/mL, and eliminated approximately 46.21% superoxide radical at the concentration of 1 mg/mL. In addition, MDI showed strong ability on reducing power, DNA damage protection and protein oxidation protection. Overall, results suggested that MDI might be beneficial as a potent antioxidant and effectively employed as an ingredient in food applications.

• Archives of Pharmacal Research
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• 제26권7호
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• pp.535-539
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• 2003

The EtOAc soluble fraction from the stem of Sorghum bicolor showed a strong free radical scavenging activity. Five major compounds were isolated from this fraction. They were identified by spectral data as methyl ferulate (1), methyl p-hydroxycinnamate (2), p-hydroxybenzaldehyde (3), tricin (4), and quercetin 3,4 -dimethyl ether (5). Among these compounds, 1 exhibited a strong, free radical scavenging activity on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) with an $IC_50$ value of 0.7 $\mu$M. We further studied the effects of these isolated compounds on the lipid peroxidation in rat liver microsomes induced by non-enzymatic method. All five compounds showed anti-lipid peroxidation activity ($IC_50$ values of 0.5, 0.4, 0.3 and 0.3 $\mu$ M, respectively).

• 생명과학회지
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• 제29권4호
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• pp.428-435
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• 2019

알래스카 산 대구(Gadus chalcogrammus)는 대구과(family Gadidae)의 해산어종이다. 알래스카 명란 원료, 고추장 명란, 발효 명란을 증류수와 에탄올로 추출하여 2, 2- diphenyl - 1- picrylhydroazyl (DPPH), 하이드록시 라디칼(OH), 산화질소(NO)의 항산화 소거능을 평가하였다. 철 이온 환원력(FRAP)을 조사하였다. ABTS+ 소거능은 Brand-Williams 등의 방법에 따랐다. 고추장 명란의 증류수 추출물의 DPPH 소거능은 1.0 mg/ml 농도에서 71.9%였으며 에탄올 추출물에서 소거능은 73.7%였다. 발효 명란의 증류수 추출물의 DPPH 소거능은 1.0 mg/ml 농도에서 78.0%였고 에탄올 추출물에서 소거능은 78.4%였다. 명란 원료의 증류수 추출물과 에탄올 추출물의 DPPH에 대한 최소 저해 농도 값($IC_{50}$)은 각각 11.65 ug/ml과 11.47 ug/ml이었다. 명란 원료, 고추장 명란, 발효 명란의 에탄올 추출물의 OH 소거능은 1.0 mg/ml 농도에서 70.9%, 79.0, and 80.6%였다. 명란 원료의 증류수 추출물과 에탄올 추출물의 NO의 최소 저해 농도 값은 11.45 ug/ml과 11.41 ug/ml였다. 본 연구 결과, 고추장 명란과 발효명란은 원료 명란 보다 높은 DPPH, OH, NO 소거능을 나타내었다. 고추장 명란과 발효 명란은 자연 라디칼 소거능이 있어 식품으로써 항산화 보충제가 될 수 있을 것이다.

• 농약과학회지
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• 제7권2호
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• pp.92-99
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• 2003

96-well plate를 사용해서 DPPH free radical 소거활성의 고효율검정 (high throughput screening)방법을 확립하였고, 이 방법을 이용하여 107개의 식물특정 효소저해제와 다양한 식물 추출물의 항산화활성을 조사하였다. DPPH free radical 소거활성 측정 측정을 위한 적정 시험조건은 총 반응액이 $250{\mu}L$일 경우 $100{\mu}M$의 DPPH(pH 7.8), 20 분의 반응시간이었고, 이 조건하에서 ascorbate와 a-tocopherol 은 농도 의존적인 항산화활성을 나타내었다. 107개의 식물 특정효소저해제 중에서 11개의 화학물질이 $100{\mu}M$ 농도에서 70% 이상의 항산화활성이 있었는데, 특히 ampicillin과 gallic acid는 각각 90.2% 와 92.6% 의 나타냈다. 또한 100개의 식물 추출물은 $50{\mu}g/mL$ 농도에서 70% 이상의 활성을 보이는 추출물이 11개이었는데, 그 중에서 AT-407의 활성이 90.1%로 가장 높게 나타났다. 따라서 96-well plate를 이용한 DPPH free ra 이때 소거활성 측정방법은 여러가지 합성물질이나 다양한 천연물질에 대하여 보다 간편하고 신속하게 항산화활성을 측정할 수 있을 것으로 사료되었다.

• 대한의생명과학회지
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• 제14권3호
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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.

• Advances in Traditional Medicine
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• 제8권4호
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• pp.329-338
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• 2008

The aim of the study is to investigate the antioxidant activity through, reducing power, 2, 2-diphenyl-1-picryl hydrazyl radical (DPPH), nitric oxide radical (NO), superoxide radical, hydrogen peroxide radical ($H_2O_2$) scavenging activity and the amount of total phenolic compounds of chloroform, ethyl acetate, methanol and aqueous extracts of the leaves of Talinum portulacifolium. Chloroform extract of leaves of T. portulacifolium showed highest antioxidant activity, with a direct relationship between activity and concentration of extracts ($15-240\;{\mu}g/mL$). Among all the extracts, the highest amount of the total polyphenolic compounds was found in the chloroform extract. Chloroform extract of T. portulacifolium showed an important free radical scavenging activity towards the DPPH, NO, Superoxide and $H_2O_2$ radicals, with $IC_{50}$ values of 133.26, 165.75, 156.34 and $135.29\;{\mu}g/mL$, respectively. In the lipid peroxidation assay, extracts of chloroform and ethyl acetate showed a remarkable inhibitory activity. The extracts showed significant activity in all the experiments but lower than the standard antioxidant, ascorbic acid.