• The Korean Journal of Food And Nutrition
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• v.30 no.6
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• pp.1332-1340
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• 2017

In this study, we assessed antioxidant, anti-diabetic, and anti-Alzheimer activities of Opuntia ficus-indica var. saboten (OFI) at harvest time. OFIs were cultivated December 2015~November 2016 in Jeju island. The 70% ethanol extracts of OFI were used to investigate total polyphenol and flavonoid contents, antioxidant(DPPH and ABTS radical scavenging assay), anti-diabetic(yeast ${\alpha}$-glucosidase and rat ${\alpha}$-glucosidase inhibition assay), and anti-Alzheimer(Acetylcholinesterase and butyrylcholinesterase inhibition assay) activities. Total polyphenol and flavonoid contents of OFIs were $17.40{\sim}23.11{\mu}g$ garlic acid/mg Ex and 2.17~6.22 ug (+)-catechine/mg Ex, respectively. DPPH and ABTS radical scavenging activity of OFIs were 131.98~184.90 mg ascorbic acid(AA) eq/100 g and 63.60~101.83 mg AA eq/100 g, respectively. In the anti-diabetic and anti-Alzheimer activities, 70% ethanol extracts of OFI exhibited moderate inhibition activity, compared to control (acarbose and beberine). Total polyphenol and flavonoid contents, antioxidant, anti-diabetic, and anti-Alzheimer activities were no significant differences by season, respectively. Therefore, information on comparative biological evaluations of OFI may be a beneficial in exploring functional food and drug development.

• Food Science and Preservation
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• v.24 no.3
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• pp.483-489
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• 2017

Phloridzin is a predominant member of the chemical class of dihydrochalcones and mainly found in apple. The biological activity of phloridzin treated with dielectric barrier discharge (DBD) plasma was evaluated to investigate whether exposure to plasma can be used as a tools to enhance the biological activity of natural resources. DBD plasma treatment of phloridzin was carried out for three different exposure times. The antioxidant effects of degraded phloridzin for different reaction time were evaluated via radical scavenging assay using DPPH radical. In addition, the anti-diabetic and anti-obesity properties of the degraded phloridzin were measured based on ${\alpha}$-glucosidase and pancreatic lipase inhibitory activities. Phloridzin treated for 60 min showed significantly higher radical scavenging, ${\alpha}$-glucosidase and pancreatic lipase inhibitory activities compared to the tested positive controls. Degradation of phloridizin induced by DBD plasma might be responsible for enhancing the biological activity of phloridizin.

• 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.

• Korean Journal of Pharmacognosy
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• v.29 no.4
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• pp.338-346
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• 1998

In order to elucidate the relationship between anti-HIV-1 enzyme activity and inhibition of HIV-1 replication by natural sources, extracts from some plants using the foods and oriental medicines were tested for inhibitory effects on the viral replication, reverse transcriptase (RT), protease and ${\alpha}-glucosidase$. In the anti-RT test, water extracts of Ficus carica (leaf), Houttuynia cordata (aerial part) and Ixeris tamagawaensis (aerial part) showed more than 79% inhitibion at a concentration of $100\;{\mu}g/ml$. The protease and ${\alpha}-glucosidase-inhibiting$ samples in the screening were water extract of Syringa dilatata (leaf) and methanol extract of Hibiscus syriacus (leaf and stem), which showed more than 40% inhibition at a concentration of $100\;{\mu}g/ml$. In the primary anti-HIV-1 test, water extracts of Equisetum arvense (aerial part), Hibiscus syriacus (leaf), Ixeris tamagawaensis (aerial part) and Pueraira thunbergiana (leaf) showed the potent inhibition against HIV-1 induced cytopathic effects.

• Journal of Mushroom
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• v.12 no.4
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• pp.330-340
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• 2014

Coprinellus micaceus, belongs to family Psathyrellaceae of Agaricales, Basidiomycota, has been used for edible purposes in the world. This study was initiated to evaluate the antioxidant, anti-diabetic, anti-cholinesterase, anti-tyrosinase, and nitric oxide inhibitory activities of fruiting bodies from C. micaceus extracted with methanol and hot water. The HPLC analysis of phenolic compounds from the mushroom extracts identified 4 phenolic compounds including procatechuic acid, chlorogenic acid, (-)-epicatechin, and naringin. In 1,1-diphenyl-2-picrylhydrazyl(DPPH) free radical scavenging assay, the scavenging activities of methanol and hot water extracts were lower than that of positive control, BHT. The chelating effects of methanol and hot water extracts were significantly higher than that of BHT, the positive control at the all concentrations tested. In the reducing power assay, methanol and hot water extracts exhibited the lower activities compared with positive control at the 0.125-0.2 mg/ml. The methanol and hot water extracts of the mushroom inhibited the ${\alpha}$-glucosidase activity by 62.26% and 67.59%, respectively at the 2.0 mg/ml, while acarbose, the positive control, inhibited the ${\alpha}$-glucosidase activity by 81.81% at the same concentration. In the acetylcholinesterase(AChE) inhibitory activity assay, methanol and hot water extracts of the mushroom inhibited the AChE by 94.64% and 74.19%, respectively at 1.0 mg/ml, whereas the galanthamine, standard drug, inhibited the AChE activity by 97.80% at the same concentration. The tyrosinase inhibitory activities of methanol and hot water extracts were 91.33% and 91.99% at 2.0 mg/ml, while the inhibitory activity of kojic acid, the positive control, was 99.61% at the same concentration. Nitric oxide(NO) production in lipopolysaccahride (LPS) activated RAW 264.7 cells were inhibited by the methanol and hot water extracts in a concentration dependent manner. Therefore, it is concluded that fruiting bodies of C. micaceus contained natural antioxidant, anti-acetylcholinesterase and ${\alpha}$-glucosidase inhibitory, anti-inflammatory, anti-tyrosinase substances which might be used for promoting human health.

• Korean Journal of Medicinal Crop Science
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• v.18 no.1
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• pp.34-39
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• 2010

Machilus thunbergii was an important medicinal resource and distributed widely in China. In this study, the bioactivities of dichloromethane fraction (DF) and water fraction (AF) from Machilus thunbergii methanol extract were investigated. Total phenolic contents of DF and AF were 57.90 mg Gal/g and 189.92 mg Gal/g, and total flavonoid contents were 17.34 mg Que/g and 58.38 mg Que/g respectively. The $EC_{50}$ for DPPH radical scavenging activity of DF and AF were $24.37\;{\mu}g/m{\ell}$ and $2.10\;{\mu}g/m{\ell}$. Reducing power and hydroxyl radical scavenging activities of AF were higher than those of DF. The $\alpha$-glucosidase inhibitory activity of AF ($IC_{50}\;=\;1.13\;{\mu}g/m{\ell}$) was higher than that of DF ($IC_{50}\;=\;5.34\;{\mu}g/m{\ell}$). The cell viability was showed that only the DF had anti-proliferation effect on human cancer cell HT-29. These results suggested that both the DF and AF extract of Machilus thunbergii were potential materials for anti-diabetes and functional food for their radical scavenging activity.

• Journal of Life Science
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• v.33 no.10
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• pp.783-790
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• 2023

Modern people have an increased incidence of metabolic diseases due to changed eating habits, and diabetes is considered the most significant metabolic disease. Given that existing diabetes treatments are accompanied by side effects, the aim of this study was to identify traditional natural products that have anti-diabetic activity. The potential anti-diabetic and antioxidant activities of natural products were examined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay, α-glucosidase assay, and protein tyrosine phosphatase 1B (PTP1B) inhibition assay. Methanol extracts of Ulmus davidiana var. japonica, Acer tegmentosum branches, Nelumbo nucifera seeds, and Carthamus tinctorius seeds were found to have high anti-diabetic activity and further fractionated with solvents using ethyl acetate and butanol. Consequently, the ethyl acetate fraction of C. tinctorius seeds (MG-11-E) with high α-glucosidase and PTP1B inhibitory activity was selected. MG-11-E was subjected to preparative thin layer chromatography, and fraction #6 showed high α-glucosidase and PTP1B inhibitory activity. Fraction #6 was analyzed and fractionated via high performance liquid chromatography with 50% methanol as the mobile phase, and anti-diabetic activity was observed in the sample that eluted after 4 min as a single peak. The α-glucosidase inhibitory activity exhibited by this sample seemed to be greater than the PTP1B inhibitory activity; thus, it was concluded that a greater anti-diabetic therapeutic effect may be achieved by combining this agent with natural products that inhibit PTP1B activity.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1739-1744
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• 2010

In this study, the bioactivities of ethanol (EEAR) and water extract (WEAR) from the leaf of Aceriphyllum rossii were investigated. In the anti-oxidative activity, IC50 of DPPH radical scavenging activity was respectively 549.86 and $62.14{\mu}g$/mL by EEAR and WEAR. Anti-inflammatory activity of EEAR and WEAR has been evaluated on inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) release by the macrophage RAW 264.7 cells. EEAR and WEAR inhibited inflammatory by 5.58 and 16.85% in 10 mg/mL, respectively. In the anti-diabetic activity, $IC_{50}$ of $\alpha$-glucosidase inhibitory activity was 5.62 and $425.63{\mu}g$/mL by EEAR and WEAR. $IC_{50}$ of $\alpha$-amylase inhibitory activity of EEAR and WEAR was 4,623.87 and over $10,000{\mu}g$/mL, respectively. In the anti-obesity, all lipase inhibitory activity ($IC_{50}$) of EEAR and WEAR was up $10,000{\mu}g$/mL. Finally, EEAR and WEAR exhibited anti-oxidative and anti-diabetic activity. It suggests that Aceriphyllum rossii could be potentially used as a resource of bioactive materials for health functional foods.

• Food Science and Preservation
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• v.25 no.1
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• pp.117-123
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• 2018

This study was designed to determine the biological activities of Chionanthus retusus flower extracts. Water and 90% ethanol extracts of C. retusus flower were prepared. The inhibitory activities of water and ethanol extracts with a phenolic content of $200{\mu}g/mL$ against xanthine oxidase were 25.60% and 15.92%, respectively. Further, the water extract did not show any inhibitory activity against ${\alpha}$-glucosidase whereas the ethanol extract showed 100.00% inhibition of ${\alpha}$-glucosidase. The inhibitory activities of the extracts against tyrosinase were 17.27% (water extract) and 36.13% (ethanol extract), which suggest that the extracts may have a whitening effect. The water extract did not inhibit elastase activity but showed a collagenase-inhibitory activity of 20.21%. On the contrary, the ethanol extract showed 96.26% and 35.93% inhibition of collagenase and elastase, respectively. These findings suggest that the extracts may have an anti-wrinkle effect. Lastly, the extracts showed a hyaluronidase inhibitory activity of 36.96% (water extract) and 88.70% (ethanol extract), suggesting that they may have an anti-inflammatory effect. The results indicate that C. retusus flower extracts containing phenolic compounds can be used as functional resources because they have anti-gout, carbohydrate degradation-inhibitory, whitening, anti-wrinkle, and anti-inflammatory effects.