• Archives of Pharmacal Research
• /
• v.29 no.3
• /
• pp.199-202
• /
• 2006

From the leaves of Goniothalamus tenuifolius, a new natural product namely 3'-hydroxy-3,5,7,4'-tetramethoxyflavone (1) was isolated, along with seven other known compounds (2-8). Each of these isolates was evaluated for free radical scavenging activity on the DPPH decoloration test. The data obtained in this study suggested that the ortho 3',4'-diphenolic structure was essential for the activity of these flavonol derivatives.

• Journal of Applied Biological Chemistry
• /
• v.50 no.3
• /
• pp.115-119
• /
• 2007

To discover the sources with antioxidant and tyrosinase inhibitory activities in Korean traditional medicines, 10 extract of medicinal plants were screened for their potential to scavenge stable 1,1-diphenyl-2-picryhydrazyl (DPPH) free radical, inhibit hydroxyl radical (${\cdot}OH$), total phenolic content, and inhibition of tyrosinase. The potency of DPPH radical scavenging activity was shown in the extract of Ulmus davidiana var. japonica Nakai that has a greater effect with $IC_{50}$ values of $6.49{\pm}5.43{\mu}g/mL$, than BHA ($IC_{50}=20.99{\pm}0.74{\mu}g/mL$), L-ascorbic acid $(IC_{50}=20.59{\pm}1.06{\mu}g/mL),\;and\;{\alpha}-tocopherol\;(IC_{50}=25.55{\pm}0.26{\mu}g/mL)$ as a positive control. The ${\cdot}OH$ scavenging activities were observed in the plants tested. Acanthopanax senticosus, Cirsium setiders, U. davidiana exhibited scavenging activity of more than 60% at $500{\mu}g/mL$. The scavenging activity(%) of BHA and a-tocopherol were 64.32 and 55.87% at $500{\mu}g/mL$, respectively. The total phenolic content was determined, in order to assess its effect on the extract's antioxidant activity. The total phenoic content of $33.37{\pm}0.52mg/g$ was conformed by methanolic extract of U. davidiana. The U. davidiana and Morus bombycis exhibited tyrosinase inhibitory activity with a $34.28{\pm}1.32\;and\;75.57{\pm}1.10%$, respectively. In particular, M. bombycis has stronger tyrosinase inhibitory activity than albutin with $36.48{\pm}3.56%$ as a positive control. This work showed that the inhibitory abilities of Korean medicinal plants, such as U. davidiana and M. bombycis, on DPPH free radical, inhibit hydroxyl radical (${\cdot}OH$), and inhibition of tyrosinase and total phenolic content, can be useful in the prevention and treatment of free radical-relate disease. Investigations into further isolation of inhibitory principles of U. davidiana and M. bombycis are now in progress.

• The Korean Journal of Food And Nutrition
• /
• v.21 no.2
• /
• pp.135-142
• /
• 2008

This study investigated to develop new functional yogurt added domestic yuza(Citrus junos). In order to make the most effective yogurt, yuza extract and fructose were mixed at different proportions. DPPH free radical scavenging activity of yuza yogurts increased dependent on concentration. The results of the DPPH free radical scavenging activity, the 1% yuza yogurt was proven to be the best. The overall sensory score for yogurt made from adding 1% yuza ethanol extract was the best of tested yogurts. The antioxidant activity(DPPH free radical scavenging activity) was the highest in 1% yuza yogurt. The quality characteristics of prepared yogurt were evaluated in terms of acid production(pH and titratable acidity), viscosity, color and levels of lactic acid bacteria during storage period. During storage, the quality of yogurt made from adding yuza extract was better than control(without yuza extract). The sedimentation of curd was repressed a little by adding 1% yuza extract.

• Korean Journal of Medicinal Crop Science
• /
• v.21 no.3
• /
• pp.197-203
• /
• 2013

We studied the total polyphenol content, DPPH radical scavenging activity, hydroxyl radical scavenging activity and ${\alpha}$-glucosidase inhibition of water extracts from 17 medicinal plants. Total polyphenol contents ranged from 10.0 (Coix lachryma-jobi L, CL) ~ 279.7 (Perilla sikokiana, PS)mg/g. The water extract from medicinal plants were evaluated for its free radical scavenging activities and compared with a commercial antioxidant, ascorbic acid. DPPH radical scavenging activity of Pyrus pyrifolia (PP), Chamaecyparis obtusa L. (COL), Chamaecyparis obtusa F. (COF), and PS were higher than positive control. Higher hydroxyl radical scavenging activity were shown in Acanthopanax senticosus (AS) and Cordyceps militaris (CM) than the other plants. The highest anti-${\alpha}$-glucosidase activity was observed in Cornus officinalis (CO) and Paeonia suffruticosa Andrews (PSA) water extracts. PSA showed not only the higher DPPH radical scavenging activity but also the anti-${\alpha}$-glucosidase activity. The results of our study that PP, COL, COF, PS, AS, CM, CO and PSA could be potential candidates for natural antioxidants.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2012.05a
• /
• pp.18-18
• /
• 2012

Antioxidant is an important role to protect the human body against damage by reactive oxygen species. However, the excessive intake of such antioxidant is known to cause a serious poisonous influence on one's liver, lungs and circulating system. Therefore, it is necessary to develop a safe natural antioxidant. For the purpose of developing natural antioxidant and antibacterial, the antioxidant activity and antibacterial effects of various extract solvents from Artichoke (Cynara Scolymus L.) leaf were determined. In this study, the extracts of Artichoke leaf dried from solvent extraction were examined by means of DPPH free radical scavenging activity and ABTS free radical scavenging activity. The effect of free radical scavenging compared with $\alpha$-tocopherol and L-ascorbic acid. In Artichoke leaf extract, evaluated by using DPPH and ABTS showed that the highest antioxidant activities were found to be in methanol extracts from DPPH radical ($IC_{50}$: $20.06{\mu}g\;mL^{-1}$), ABTS radical ($IC_{50}$: $16.01{\mu}g\;mL^{-1}$) and followed by ethanol > methyl chloride > ethyl acetate > n-Hexane. By using disc diffusion method, the antibacterial activity showed that the Artichoke leaf extract was found to be most effective against all of the tested organisms and the methyl chloride extract showed the most significant antibacterial effect against all of tests among 5 solvents extract, followed by ethyl acetate > n-Hexane > ethanol > methanol. As a result, optimal in antioxidant activity for Artichoke (Cynara Scolymus L.) leaf is methanol extract and for antibacterial effect is Methyl Chloride extract.

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

• Advances in Traditional Medicine
• /
• v.8 no.4
• /
• pp.329-338
• /
• 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.

• Journal of the Korean Wood Science and Technology
• /
• v.31 no.6
• /
• pp.67-72
• /
• 2003

The leaves of D. racemosum showed strong DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity and the order of the radical scavenging activity against DPPH radical is ethyl acetate (EtOAc) fraction>crude extracts>residue fraction>hexane fraction>ether fraction, under the experimental conditions. Since EtOAc fraction has highest antioxidative activity among these fractions, the isolation was performed from the EtOAc fraction of the leaves of D. racemosum and four phenolic compounds were isolated and identified as follows: methyl gallate, kaempferol, quercetin and quercitrin. The free radical scavenging activities of these compounds were 79.9%, 93.1%, 93.6% and 66.7% at 10 ㎍/ml, respectively. The IC₅₀ of compound 1, compound 2, compound 3 and compound 4 were 6.1, 4.1, 3.6 and 6.5 ㎍/ml, respectively. These compounds have higher antioxidative activity compared with reference compounds, ascorbic acid (IC₅₀ = 9.6 ㎍/ml).

• Korean Journal of Plant Resources
• /
• v.26 no.5
• /
• pp.548-556
• /
• 2013

The objective of this study was to determine the effect of antioxidant enzyme activity and radical scavenging activities of cucumber grown greenhouse. The analytic method of antioxidant activities were measured by estimating DPPH free radical scavenging, nitrite scavenging ability activity and ABTS radical scavenging ability. The DPPH free radical scavenging activity of Jangjukcheongjang was the highest in most of the growth stage. The Nitrite scavenging ability at pH 1.2 was more than 40% in all cultivars and growth stages. The ABTS radical scavenging ability of Jangjukcheongjang and Nulpureuncheongjang showed relatively little higher than Janghyeongnakhap and Sinjoeunbaekdadagi. The SOD activity showed higher activity than 95% in all cultivars and growth stages. The activity of CAT was highest in the Nulpureuncheongjang of 2 (12~16cm) growth stage, and the APX activity of Nulpureuncheongjang and Janghyeongnakhap showed a relatively high activity. The POX activity showed distinctly different trends depending on the growth stage, and that is, the activity at harvest stage was significantly reduced. These results suggest that the cucumber had the potent biological activities, and that in the future, the availability of cucumber will be increase in the field of high-value cosmetic and food products.

• Journal of the Korea Convergence Society
• /
• v.11 no.2
• /
• pp.309-314
• /
• 2020

This study was designed to investigate the antioxidant effects of 10 kinds of medicinal plants and vegetable extracts and total extracts. The cytotoxicity was measured by MTS assay, and the antioxidant activity was measured by DPPH free radical scavenging activity and Riboflavin-derived superoxide inhibitory activity (SQA). As a result, cytotoxicity was safe for all 10 medicinal plants, vegetable extracts and total extracts. DPPH free radical scavenging ability was observed in Cinnamomum cassia Blume, Eugenia caryophyllata Thunb. Arctium lappa, Total extract was excellent, and Riboflavin-derived superoxide inhibitory activity (SQA) was found in Cinnamomum cassia Blume, Arctium lappa, Prunus mume Sieb. et Zucc., Excellent, but total extract showed the best antioxidant effect. As a result of comparing the antioxidant effects of medicinal plants and vegetables using traditional ingredients, the antioxidant activity was increased when used as a mixture than when used alone. It is considered that it can be used as an antioxidant functional material, and it is expected to be of value when developing antioxidant material in the future.