• Korean Journal of Medicinal Crop Science
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• v.6 no.3
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• pp.181-187
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• 1998

This study was carried out to investigate the antioxidative activities of medicinal plants. Through the examination of methanol extracts from 30 species for radical scavenging effects using DPPH method, the extracts from Rhus javanica Linne, Smilax china Linne and Polygonum cuspidatum Siebold et Zucarinii showed strong antioxidative activity. Because of its highest antioxidative activity among 30 medicinal plants, radical scavenging effects of 4 different extract compartments (n- Hexane, EtOAc, BuOH and $H_2O$ extracts) from Galla Rhois MeOH extract of Rhus javanica Linne were examined by DPPH method and antioxidant effects on the 4 different extract compartments were tested by Ferric-Thiocyanate method. Antioxidative activities of n- Hexane, EtOAc and BuOH extracts were similar or even higher than that of natural (tocopherol) or synthetic antioxidants (BHA), suggesting that major fractions for the antioxidative activity of Rhus javanica Linne were the n- Hexane, EtOAc and BuOH extract compartments.

• Food Science and Preservation
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• v.23 no.2
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• pp.283-289
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• 2016

Naturally occurring antioxidants, such as polyphenols are widely found in fruits, vegetables, wines, juices, and other plant-based dietary sources and are divided into several sub classes, including phenylpropanoids, flavonoids, stilbenoids, and lignans. As part of the our ongoing search for bioactive food ingredients, the antioxidant and advanced glycation end products (AGEs) formation inhibitory activities of the methanolic extract of the aerial parts of Cirsium setidens were investigated in vitro bioassay system. The antioxidant properties were evaluated through radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) ($ABTS^+$) radicals. In addition, the activity of C. setidens against diabetes complications was also tested via AGEs formation inhibition assay. The total phenolic contents were determined using a UV-VIS spectrophotometric method. All tested samples showed a dose-dependent radical scavenging and AGEs inhibitory activities. In particular, the n-butanol (BuOH)-soluble portion showed the most potent radical scavenging activities against DPPH and $ABTS^+$ radicals with $IC_{50}$ values of $24.3{\pm}1.7$ and $25.0{\pm}3.3{\mu}g/mL$, respectively. Futhermore, the inhibition of AGEs formation by the n-BuOH-soluble portion ($IC_{50}$ value; $46.0{\pm}1.5{\mu}g/mL$) was higher than that those of the soluble portions for the other solvent. The results showed that C. setidens could be considered as an effective source of natural antioxidants and other ingredients.

• Journal of Life Science
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• v.23 no.7
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• pp.913-918
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• 2013

The applicability of the ultrasonic wave method to the extraction of useful components from seaweeds was investigated. Extracts from freeze-dried Ecklonia cava powder were prepared with hot water ($65^{\circ}C$), water ($24^{\circ}C$), 50% ethanol, and 100% ethanol, and ultrasonic extraction was also performed. The content of phenolic compounds and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and tyrosinase inhibitory activity of the extracts were analyzed, and differences in the data obtained by the ultrasonic extraction and the traditional extraction methods were compared. The phenolic content in the E. cava extract by ultrasonic extraction (142.80 mg/g) was approximately 14 times higher than the phenolic content in the hot water extract (10.03 mg/g). The DPPH radical scavenging and the tyrosinase inhibitory activities of the ultrasonic extract were approximately 4 times and 14 times higher than the hot water extracts, respectively. The correlation between the phenolic content and the DPPH radical scavenging activity ($R^2$=99.47) and between the phenolic content and the tyrosinase inhibitory activity ($R^2$=99.99) was very high. These results indicate that ultrasonic extraction is more suitable than traditional extraction for the extraction of useful components from E. cava.

• Food Science and Preservation
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• v.20 no.5
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• pp.684-690
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• 2013

The antioxidant and photoprotective effects of various extracts from the roots of Rumex crispus L. were evaluated. The concentrations ($IC_{50}$) of various extracts required to exert a 50% reducing effect on a DPPH radical were found to be 0.005~0.093 mg/mL. The ethyl acetate extract showed a more remarkable effect than the positive control ascorbic acid. The concentrations ($QC_{50}$) of the butanol and ethyl acetate extracts required to exert a 50% reducing effect on the singlet oxygen $^1O_2$ were found to be 0.464 and 0.365 mg/mL, respectively. Both extracts were also found to protect the in vitro biological system from the detrimental effect of a singlet oxygen $^1O_2$ on type II photosensitization in E. coli and genomic DNA. Among all the tested extracts, the ethyl acetate and butanol extracts contained higher amounts of total phenolic contents. The results suggest that our study may contribute to the development of new bioactive products with potential applications to the reduction of photo-produced oxidative stress involving reactive oxygen species in living organisms.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.1
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• pp.60-66
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• 2014

The aim of this study was to evaluate the antioxidant activity and protective effect of extracts from the stems and leaves of Chrysanthemum boreale (CBSL) on t-BHP induced oxidative stress in human liver cells (Chang cells). Antioxidant activities in the extracts were determined for various radical scavenging activities including ferric reducing antioxidant power, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity, and oxygen radical absorbance capacity (ORAC). CBSL showed a very good scavenging effect of DPPH radical ($IC_{50}$ $0.009{\pm}0.002$ mg/mL), alkyl radical ($IC_{50}$ $0.004{\pm}0.001$ mg/mL), and hydroxyl radical ($IC_{50}$ $6.742{\pm}0.152$ mg/mL). CBSL also showed a strong antioxidant effect in the ORAC assay. In the MTT assay on human liver cells (Chang cells), the extracts showed protective effects by increasing cell viability, decreasing ROS, and restoring mitochondria membrane potential upon t-BHP induced oxidative stress. Our findings suggest that CBSL extracts are a potential therapeutic with protective antioxidant effects upon oxidative stress.

• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.205-212
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• 2014

This study was designed to investigate the antioxidant activities (ORAC value, DPPH and ABTS radical scavenging activity, FRAP activity, and reducing power) and nitrite scavenging activities of Acanthopanax senticosus extracts fermented with the mycelia of three different mushroom species: Ganoderma lucidum, Phellinus linteus, and Hericium erinaceus. The highest total phenol content (42.09 GAE mg/g) and ORAC value ($74,912{\mu}M$ TE/g) were observed in a hot water extract of A. senticosus fermented with G. lucidum. The highest DPPH radical and nitrite scavenging activities were observed in a 70% ethanol extract of A. senticosus fermented with G. lucidum. In addition, ABTS radical scavenging activity (8-88%), FRAP activity (0.1-0.2), and reducing power (0.3-0.7) were increased by ethanol addition in all samples in a dose-dependent manner. These results provide a basic understanding of the antioxidant and nitrite-scavenging activities of A. senticosus extracts fermented with different mushroom mycelia.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.11-20
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• 2012

Methanol extracts of aquatic plants were analyzed for allelopathic activities against Escherichia coli JM109 and $Microcystis$ $aeruginosa$ UTEX2385 which were compared to its 2,2-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities. The radical scavenging activities were detected from the extracts of $Persicaria$ $thunbergii$, $Persicaria$ $amphibia$, $Trapa$ $japonica$, $Myriophyllum$ $spicatum$, and $Brasenia$ $schreberi$. Also, the inhibitory activities against cyanobacteria were analyzed according to the order of $B.$ $schreberi$, $T.$ $japonica$, $P.$ $amphibia$, and $M.$ $spicatum$. Most of the extracts from aquatic plants did not show any inhibition against $E.$ $coli$ except $B.$ $schreberi$. We found a positive correlation between the antioxidental activities of methanol extract of aquatic plants and the growth inhibitory activities for cyanobacteria in terms of the DPPH radical scavenging activities ($R^2$=0.381, $P$ <0.0001). The inhibitory activities of methanol extract against $E.$ $coli$ growth was not correlated with the other activities of aquatic plants ($P$ >0.04). We suggest from this study that the allelopathic effects of aquatic plants against cyanobacteria could be screened by using the bioassay based on DPPH.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.3
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• pp.229-233
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• 2009

20 species of plants were extracted with Methanol and were investigated for DPPH radical scavenging activity and ABTs free radical scavenging activity to quest anti-oxidation ability depending on the proton beam irradiation quantity. In the proton beam irradiation, 15 species's activities increased but among them, Pharbities nil Choisy decreased at 10 KGray and 4 species' activity didn't change at all. In hydrogen ion radical elimination activity, Ulmus macrocarpa (84 %) showed the highest and Pharbitis nil Choisy showed 6 % decreasing at more than 1 KGray. By comparison with untreated $IC_{50}$ value, the beam-treated $IC_{50}$ value increased 6.3 times for Dioscorea batatas Decne. at 1 KGray, 2.1 times for Trichosanthes kirilowii Max., and 2.8 times for Dioscorea batatas Decne. at 5 KGray. In ABTs free radical elimination activity, the activity increased 60 % for Terminalia chebula Retzius compared with untreated one. Besides, the beam-treated $IC_{50}$ value increased 2 times for Gray Ephedra sinica Stapf, 2.5 times for Terminalia chebula Retz. and 2.4 times for Arctium lappa Linne at 1 KGray.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.9
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• pp.1385-1390
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• 2016

Gallic acid is a representative hydroxybenzoic acid and is found in free form in several plants and in various esterified forms as a part of hydolyzable tannins. Convenient enzymatic transformation of trihydroxylated gallic acid with polyphenol oxidase originating from pear was evaluated to investigate whether polyphenol oxidase can be used as a valuable compound to improve the biological activity of gallic acid. Enzymatic oxidation processing of gallic acid using polyphenol oxidase was carried out for five different reaction times. The antioxidant effects of transformed gallic acid for different reaction times were evaluated via radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radicals. In addition, the anti-diabetic property of the transformed gallic acid was measured based on ${\alpha}$-glucosidase. Gallic acid reacted for 5 h showed significantly higher antioxidant and ${\alpha}$-glucosidase inhibitory activities compared to the tested positive control substances. Biotransformation of simple gallic acid induced by polyphenol oxidase might be responsible for enhancing the biological activity of gallic acid.

• 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.