• Food Science and Preservation
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• v.22 no.2
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• pp.290-296
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• 2015

The antioxidant and ${\alpha}$-glucosidase inhibition activities of 10 kinds of seaweeds Ecklonia cava (EC), Ecklonia stolonifera (ES), Eisenia bicyclis (EB), Capsosiphon fulvescens (CF), Sargassum fulvellum (SF), Undaria pinnatifida (UP), Sargassum thunbergii (ST), Codium fragile (CFr), Hizikia fusiformis (HF), and Enteromorpha prolifera (EP) were investigated. Among all the tested seaweed extracts, the total polyphenol and flavonoid contents of the EB extract were highest 150.81 mg/g and 77.02 mg/g, respectively. The DPPH and ABTS radical scavenging abilities of the EB ethanol extract (1 mg/mL) were 86.26% and 99.71%, respectively, and its SOD-like activity and reducing power were 21.34% and 1.710 ($OD_{700}$). The ${\alpha}$-glucosidase inhibition activities of the EC, EB, and ST were above 98% at the 0.1 mg/mL concentration. These results suggest that seaweed extracts effectively prevent the what of antioxidants and decrease the blood glucose level, and may be used to develop various functional products.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.598-604
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• 2010

Electron donating ability (EDA), reducing power, total phenolic contents, total flavonoid contents, antimicrobial activity, and ${\alpha}$-glucosidase inhibitory effects of twenty-two sorghum varieties were examined using ethanol extracts (70%, v/v). The electron donationg abilities (EDA) of Mesusu and Bulgeunjangmoksusu (94% at 10 ${\mu}g$/mL) indicated higher antioxidant activity compared to those of other varieties and standard antioxidants such as BHT (13%) and BHA (74%). The reducing power of Mesusu ($OD_{700}$=0.71) suggested higher antioxidant activity, which was dependent on sample concentration. Bitjarususu showed the highest content of total phenolics (22.9 mg GAE/g); however, extracts from Heuinsusu exhibited the lowest content of total phenolics (16.4 mg GAE/g). Jangmoksusu showed the highest total flavonolic contents (3.5 mg QE/g), and Sigyeongsusu and Chal (GS) susu displayed the most antibacterial activity (MIC=8 ${\mu}g$/mL) against Escherichia coli. Extracts of Bulgeunjangmoksusu, Moktaksusu, and Ginjangmoksusu showed the highest ${\alpha}$-glucosidase inhibitory effect (98%) at the concentration of 5 ${\mu}g$/mL.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1308-1315
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• 2017

This study was conducted to develop Momordica charantia L. juice fermented by four Lactobacillus species such as Lactobacillus paracasei (LPA), Lactobacillus plantarum (LPL), Lactobacillus rhamnosus (LRH), and Lactobacillus reuteri (LRE) as well as to investigate their inhibitory effects against digestive enzymes and antioxidant activities. Fermentation was performed at $37^{\circ}C$ without nutrient supplementation for 72 h. The pH and total lactic acid contents were within the ranges of 3.75~3.96 and 5.21~10.04% in fermented juices, respectively. The type of starter culture and fermentation time induced changes in flavonoid contents more than total phenolic contents. All juices fermented for 48 h strongly inhibited ${\alpha}$-glucosidase activity with the percentage of inhibition ranging of 91.24~95.05%. Antioxidant activities of all juices mostly increased after 48 h of fermentation. Our results suggest that fermented juice possesses inhibitory activity against digestive enzymes and antioxidant activity, and they can be used as health functional beverages.

• Korean Journal of Food Science and Technology
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• v.49 no.4
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• pp.438-443
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• 2017

The biological activity of crude polyphenol fractions (WphF, EphE, VphF, and SphF) extracted from Cedrela sinensis using hot water, ethanol, and enzymes such as Viscozyme and Shearzyme was examined in this study. The yield of VphF was the highest (43.44%) among all fractions. The total polyphenol and flavonoid content of the fractions were highest after ethanol extraction (447.98 and 337.49 mg/g, respectively). Fractions obtained after hot water and ethanol treatment showed high antioxidant activity. All fractions, except for WphF, showed a significantly higher ${\alpha}$-glucosidase inhibitory activity than the acarbose. EphF and WphF showed the high acetylcholinesterase inhibition activity. All fractions showed more than 50% tyrosinase inhibition activity at 2 mg/mL concentration. According to these results, the crude polyphenol fractions from C. sinensis showed high antioxidative, ${\alpha}$-glucosidase inhibitory, and tyrosinase inhibitory activities. This study suggests that crude polyphenol fractions from C. sinensis, especially the WphF and EphF fractions, are good sources of functional food.

• Korean Journal of Pharmacognosy
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• v.47 no.4
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• pp.343-351
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• 2016

The purpose of this study was to evaluate the whitening effect of aerial part of Pueraria lobata and mechanisms. Aerial part of Pueraria lobata, dose-dependently reduced the melanin content. Aerial part of Pueraria lobata, significantly decreased cellular tyrosinase activity, while there was not any effect on tyrosinase in cell-free conditions. To elucidate the mechanisms behind the aerial part of Pueraria lobata, treated melanogenesis regulation, the expressions of melanogensis related genes, proteins, and the activity of ${\alpha}-glucosidase$ were determined. Aerial part of Pueraria lobata, significantly inhibited gene and protein levels of MITF, tyrosinase and TRP-1. It suppressed the ${\alpha}-glucosidase$, leading to inhibition on the maturation of tyrosinase. Also aerial part of Pueraria lobata, was observed to have the high antioxidant activity. These results suggested that whitening effect of aerial part of Pueraria lobata, should be due to the down-regulation of MITF, tyrosinase and TRP-1 expression and the intercepting maturation of tyrosinase through suppressing ${\alpha}-glucosidase$. Another should be the high anti-oxidant activity. The findings show the possibility that aerial part of Pueraria lobata, can be used as a potential skin-whitening agent.

• Journal of Food Hygiene and Safety
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• v.29 no.1
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• pp.53-59
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• 2014

This study was carried out to investigate the effect on the growth and antioxidant activities of Cichorium intybus L.(CLE), Cichorium intybus L. var. folisum 'treviso' (CLET), Cichorium intybus L. var. folisum 'rosaitaliana' (CLER) in hydroponics added with $Cr^{3+}$ or Selenium (Se) for 4 weeks. Total polyphenol, total flavonoids contents and FRAP values of three species of chicory were grown hydroponically with $Cr^{3+}$ or Se were increased. These extracts were also showed stronger DPPH and ABTS scavenging activity than chicory extracts. In particular, chicories added with $Cr^{3+}$ had higher antioxidant activities than chicories added with Se. CLER and CLE extracts added with $Cr^{3+}$ were also showed ${\alpha}$-glucosidase inhibition activities. These results indicate that chicories were cultivated in culture fluid added with $Cr^{3+}$ or Se could be used as high functional vegetables.

• Journal of Life Science
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• v.18 no.7
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• pp.963-967
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• 2008

The biological activities of water extracts from different fruit parts, such as peel, flesh, and placenta, of oriental melon were investigated. The concentrations of total phenolic in fruit extracts were $816.37\;{\mu}g/ml$, $385.23\;{\mu}g/ml$, and $925.56\;{\mu}g/ml$, respectively. Whereas the total flavonoid content in the peel extracts was $231.21\;{\mu}g/ml$, those in the extract of flesh and placenta were $8.16\;{\mu}g/ml$ and $36.07\;{\mu}g/ml$, respectively. The DPPH free radical scavenging activity of each fruit extract at 10,000 ppm was 34.84% for peel, 10.70% for placenta and 9.26% flesh. The ABTS radical cation decolorizing activity of each fruit extract at 10,000 ppm was in fruit extracts were 72.92% for peel, 48.0% for flesh and 74.31% for placenta. In addition, xanthine oxidase inhibitory activity, ${\alpha}-Glucosidase$ inhibition activity, and tyrosinase inhibition activity of the peel extracts appeared to be higher than those of placenta and flesh. Taken together, these results indicated that the peel part of oriental melon contained higher level of total flavonoid content, and several physiological activities including antioxidation, ${\alpha}-Glucosidase$ inhibition activity, and tyrosinase inhibition activity than did the flesh and placenta parts, and suggested that the peel might have a potential to be applicable as a source for functional foods.

• Korean Journal of Pharmacognosy
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• v.50 no.2
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• pp.141-147
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• 2019

The aim of this study was to investigate the potential of Acanthopanax sieboldianum (Makino) Koidz (ACS) as a potent antioxidant and antidiabetic agent. The antioxidative and alpha-glucosidase inhibitory activities were examined using the methanol extracts and solvent fractions from ACS-leaf and ACS-stem. Antioxidative activities were measured by in vitro methods such as DPPH and ABTS radical scavenging activity and superoxide dismutase (SOD) activity. When the chloroform and ethyl acetate fractions of ACS-leaf and ethyl acetate fractions of ACS-stem were compared with the control, the SOD-like activity was impaired even at the low treatment concentrations. In addition, the ethyl acetate fractions of ACS-leaf and ACS-stem showed alpha-glucosidase inhibition activities at low treatment concentrations. Analysis of the major components in the fractions of ACS-leaf and ACS-stem was also performed using HPLC. Finally, astragalin, isoqurecetin, chlorogenic acid and caffeic acid contents were measured. Based on this work, we propose that ACS-leaf and ACS-stem have great potential as natural antioxidant and antidiabetic materials related to health benefits.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1633-1639
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• 2009

Water extracts were extracted on water bath for 3 hrs at 90${^{\circ}C}$ after 5 times water was added to hot-air dried garlic (DG) and red ginseng (RG), respectively. Its extracts were dried on rotary evaporator, and then the mixture samples were prepared from RG extracts added to DG extracts at 5, 10, and 15%. To test biological activities such as DPPH, nitrite scavenging, tyrosinase, $\alpha$-glucosidase, human gastric (AGS), and human colon cancer cell (HT-29) growth, dryness of DG, RG, and mixture samples were diluted 500-10,000 $\mu$g/mL adding deionized water, respectively. DPPH scavenging activities of mixture sample were slightly higher than DG and RG sample alone. Nitrite scavenging activity was the highest in DG, and the other samples were below 45%. Inhibition activity of tyrosinase was below 35.0% in tested all samples. Inhibition activity of $\alpha$-glucosidase was lower in DG or RG alone, while its activity of mixture sample was increased in proportion to concentration of RG extracts. Inhibition of AGS cell growth was more effective in mixture samples than DG and RG alone, while inhibition of HT-29 cell growth was more effective in DG or RG alone than mixture samples.

• Journal of Plant Biotechnology
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• v.46 no.1
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• pp.37-44
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• 2019

The objective of this study was to compare the effects of different concentration of ethanol extraction on the total phenol and flavonoid contents and physiological activities. The total phenol content of the extracts ranged from 35.54 to 71.52 mg GAE/g. An increase in the ethanol concentration of the solvent led to an increase in the phenol content, with the highest content being found in the 80 and 99.5% ethanol extract. The same trend was observed for flavonoid content. DPPH, nitric oxide, superoxide, hydroxyl radical scavenging activity and TEAC, FRAP and ORAC were measured by antioxidant assay. Radical scavenging activity of aqueous ethanol extracts was better than that of water and 99.5% ethanol extracts. TEAC and FRAP were highly dependent on ethanol concentration and ORAC showed high activity in 40 ~ 80% ethanol extract. Antioxidant activity of Dolwoe leaves tea showed different results among the assay systems. In most experiments, the activities of water and 99.5% ethanol extracts was relatively low. ${\alpha}$-Glucosidase inhibitory activity and microorganism inhibitory activity were highest in the 80% and 99.5% ethanol extracts. Therefore, it was considered that extraction with 80% ethanol was appropriate when considering the antioxidative and physiological activities of Dolwoe leaves tea. Based on these results, it can be used as a basic data for the development of food of Dolwoe leaves tea.