• 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.

• 대한간호학회지
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• 제33권2호
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• pp.170-178
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• 2003

Purpose: This study was to determine the effect of oral vitamin C supplements on blood sugar and antioxidative status in Types II diabetes mellitus patients. Method: Data for the study were collected from June 24 to August 31, 2001. Participants(31) took 1g/day vitamin C for 4 weeks, after a 1 - week taking no Vitamin C, followed by Vitamin C 3g/day for 4 weeks. A baseline blood sample was obtained following a 12hour overnight fast and at the end of each 4week Vitamin C administration. Blood samples were taken for plasma vitamin C concentration, fasting blood sugar, HbA1c, superoxide scavenging activity and hydrogen peroxide scavenging activity. The data were analyzed by SPSS for repeated measures ANOVA. Result: Plasma vitamin C concentration was significantly increased over dose(F=3.316, p=.043). Fasting blood sugar and HbA1c was significantly decreased over dose(F=13.192, p=.000; F=11.995, p=.000). Superoxide scavenging activity and hydrogen peroxide scavenging activity was significantly increased over dose(F=486.138, p=.000; F=177.704, p= .000). Conclusion: The results suggest that megadose vitamin C supplementation may have a beneficial effect in diabetes mellitus patients on both glycemic control and antioxidant status. Thus dietary measures to increase plasma vitamin C may be an important health strategy for reducing the compliance of diabetic patients

• 한국식품영양과학회지
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• 제42권4호
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• pp.512-519
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• 2013

본 연구에서는 전통적으로 질병치료와 예방의 목적으로 사용되어온 약용식물 10종을 선정하여 총 페놀 및 총 플라보노이드 함량과 항산화 효과를 측정하였다. 약용식물의 총 페놀 함량을 측정한 결과 화피 추출물이 320.10 mg/g, 갈근이 153.93 mg/g으로 높게 나타났으며, 총 플라보노이드 함량은 화피 추출물이 226.25 mg/g, 황금 추출물이 101.98 mg/g으로 높았다. 약용식물 중 가장 높은 DPPH 라디칼 소거능을 나타낸 시료는 화피로 $IC_{50}$ $5.39{\mu}g/mL$를 나타냈으며, 그 다음으로 헛개나무($IC_{50}$ $24.87{\mu}g/mL$), 오가피($IC_{50}$ $27.79{\mu}g/mL$) 순으로 높게 나타났다. 아질산 소거 활성 측정결과 헛개나무가 $IC_{50}$ $173.96{\mu}g/mL$, 화피 추출물이 $IC_{50}$ $167.94{\mu}g/mL$로 비슷한 활성을 나타내었다. $Superoxide^-$ 라디칼 소거능과 $ABTS^+$ 라디칼 소거능에서는 화피와 오가피가 유의적으로(p<0.001) 높은 소거능을 보였다. 환원력에 대한 흡광도 값을 측정한 결과는 10종의 약용식물 중에서 화피 추출물이 2.72의 흡광도를 나타내어, 양성대조군인 비타민C의 3.04과 비교해도 크게 뒤떨어지지 않음을 알 수 있었다. 본 연구의 결과 화피, 헛개나무, 오가피 추출물은 총 페놀 및 플라보노이드 함량이 높고, 항산화 활성도 높게 나타나 식품첨가물 및 식품보존제 등 기능성 소재로써 활용될 수 있을 것으로 사료된다.

• 한국식품과학회지
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• 제40권3호
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• pp.283-289
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• 2008

민들레 잎의 열수 추출물의 항산화 활성 증진을 위한 추출조건을 최적화하기 위하여 반응표면분석법을 사용하였다. 중심합성 계획에 따라 추출조건의 독립변수(추출온도, 용매비, 추출시간)와 이에 따라 영향을 받는 종속변수(수율, 총 폴리페놀 함량, 총 플라보노이드 함량, DPPH 라디칼 소거활성, ABTS 라디칼 소거활성, superoxide 라디칼 소거활성)를 설정하였다. 추출물의 수율은 추출시간에 의해 거의 영향을 받지 않는 것으로 나타났으며 시료의 용매비가 증가할수록 감소하였고, $70^{\circ}C$ 이상의 추출온도에서 감소하는 것으로 나타났다. 총 폴리페놀과 총 플라보노이드 함량은 추출온도가 증가함에 따라 크게 증가하였으며, DPPH 라디칼, ABTS 라디칼, superoxide 라디칼 소거활성도 추출온도에 가장 크게 영향을 받아 추출온도가 증가함에 따라 증가하다가 최적온도 이후에 약간 감소하는 것으로 나타났다. 이들 추출물의 특성을 모두 만족시키는 최적 추출조건은 추출 온도 83.77$\pm$1.07$^{\circ}C$, 시료에 대한 용매비 20.85$\pm$0.24 mL/g, 추출시간 1.59$\pm$0.12 hr이었고 이 때 예측된 수율은 38.98%, 총 폴리페놀 함량은 74.28 ${\mu}g$/mg, 총 플라보노이드 함량은 74.00 ${\mu}g$/mg이었으며, DPPH 라디칼, ABTS 라디칼, superoxide 라디칼의 소거활성($IC_{50}$)의 예측 특성값은 각각 0.14 mg/mL, 3.24 mg/mL, 2.49 mg/mL로 나타났다.

• Advances in Traditional Medicine
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• 제4권3호
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• pp.197-209
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• 2004

The study was aimed at evaluating the antioxidant and antimicrobial activities of methanol extract of Caesalpinia bonducella leaves (MECB) (Family: Caesalpiniaceae). The effect of MECB on antioxidant activity, reducing power, free radical scavenging (DPPH radical, nitric oxide radical, superoxide anion radical, hydroxyl radical and hydrogen peroxide radical scavenging), total phenolic content and antimicrobial activities were studied. The antioxidant activity of MECB increased in a dose dependent manner. About 50, 100, 250 and 500 g of MECB showed 53.4, 61.2, 69.1 and 76.2 % inhibition respectively on peroxidation of linoleic acid emulsion. Like antioxidant activity, the effect of MECB on reducing power increased in a dose dependent manner. The free radical scavenging activity of MECB was determined by DPPH radical scavenging method. The potency of this activity was increased with increased amount of extract. MECB was found to inhibit the nitric oxide radicals generated from sodium nitroprusside $(IC_{50}\;=\;102.8\;g/ml)$ whereas the $IC_{50}$ value of curcumin was 20.4 g/ml. Moreover, the MECB was found to scavenge the superoxide generated by photoreduction of Riboflavin. MECB was also found to inhibit the hydroxyl radical generated by Fenton reaction, where the $IC_{50}$ value is 104.17 g/ml compared with catechin 5 g/ml, which indicates the antioxidant activity of MECB. The MECB capable of scavenging hydrogen peroxide in a concentration-dependent manner. The amounts of total phenolic compounds were also determined. Antimicrobial activities of MECB were carried out using disc diffusion methods with five Gram positive, four Gram negative and four fungal species. The results obtained in the present study indicate that MECB leaves are potential source of natural antioxidant and antimicrobial agents.

• Asian-Australasian Journal of Animal Sciences
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• 제18권4호
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• pp.567-573
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• 2005

This study aims to evaluate the antioxidative activities of cow-milk kefir and goat-milk kefir. Antioxidative mechanisms, including radical-scavenging effects, ferrous-ion chelating ability, reducing power and antioxidant activity, were investigated herein. Kefirs demonstrated significantly greater scavenging effects upon 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide radicals, an inhibition effect upon linoleic-acid peroxidation, and more substantial reducing power, but reduced glutathione peroxidase (GSH-Px) activity than was the case for milks. There was no significant difference between milks and kefirs as regards ferrous-ion chelating ability and superoxide dismutase (SOD) activity. These findings have demonstrated that kefirs possess antioxidant activity, thereby suggesting that kefirs are potential candidates for the role of useful natural antioxidant supplements for the human diet.

• Food Science and Biotechnology
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• 제14권1호
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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.

• Advances in Traditional Medicine
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• 제9권2호
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• pp.128-134
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• 2009

The antioxidant potency of methanolic extract Clerodendrum infortunatum Linn. (MECI), which are widely used in the Indian indigenous system of medicine for different purposes, was studied. The antioxidant potential was evaluated using different established in vitro antioxidant tests viz. determination of total amount of polyphenolics compounds, DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging, nitric oxide scavenging, superoxide anion radical scavenging, hydroxyl radical scavenging and reductive power assay. It was found that MECI contain a high amount of polyphenolics and possesses significant free radical scavenging activity in all the assay. The higher activity was may be due to presence of richest amount of polyphenolics and flavonoids in it.

• Archives of Pharmacal Research
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• 제27권2호
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• pp.173-176
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• 2004

Three phenolic compounds, rosmarinic acid (1), methyl rosmarinate (2), ethyl rosmarinate (3), and two flavonoids, luteolin (4), luteolin-7-O-$\beta$-D-glucuronide methyl ester (5) were isolated from the aerial part of Lycopus lucidus (Labiatae). Their structures were determined by chemical and spectral analysis. Compounds 1-5 exhibited potent antioxidative activity on the NBT superoxide scavenging assay. The $IC_{50}$ values for compounds 1-5 were 2.59, 1.42, 0.78, 2.83, and 3.05 $\mu\textrm{g}$/mL respectively. In addition, five compounds were isolated from this plant for the first time.

• 생약학회지
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• 제43권4호
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• pp.297-301
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• 2012

In the course of screening for antioxidant compounds by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH), a total extract of the twigs of Taxillus delavayi (Loranthaceae) was found to show potent radical scavenging activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of two phenolic compounds, catechin (1) and galloyl catechin (2), as active principles. Their structures were elucidated by spectroscopic studies. These two compounds showed the significant antioxidative effects on DPPH, and riboflavin- and xanthin-originated superoxide quenching activities. And these two compounds also showed strong nitric oxide radical scavenging effects. In riboflavin- and xanthin-originated superoxide quenching activities and nitric oxide radical scavenging effect, compound 2 showed better antioxidant activities than vitamin C.