• Preventive Nutrition and Food Science
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• v.16 no.4
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• pp.328-332
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• 2011

After preparation of acetone, ethanol, methanol, and water extracts (10 g/300 mL) of dried persimmon (Diospyros kaki cv. Fuyu) flower-buds, total phenolic contents (TPC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (RSA), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) RSA, reducing power (RP), and tyrosinase inhibitory activity of the extracts were evaluated. The methanol extracts produced the highest TPC (113.39 mg gallic acid equivalents/g), DPPH RSA ($IC_{50}=40.25\;{\mu}g/mL$), ABTS RSA ($IC_{50}=58.17\;{\mu}g/mL$) and RP ($IC_{50}=69.43\;{\mu}g/mL$) activities while the water extracts generated the lowest values. The ethanol extract showed the highest tyrosinase inhibitor activity (88.90%) at a concentration of 1 mg/mL. These results indicated that persimmon flower-buds may be a useful source of natural antioxidants.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.713-719
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• 2011

The antioxidant activities of the ethanol extract of Arctium lappa were assessed by measuring the 1,1-diphenyl-2-picrylhydrazyl( DPPH) radical scavenging effect, inhibition of $Fe^{2+}$-induced lipid peroxidation, inhibition of malondialdehyde(MDA)-bovine serum albumin(BSA) conjugation reaction and antimutagenic capacities using the Ames test. The DPPH radical scavenging activity and inhibition of $Fe^{2+}$-induced lipid peroxidation of the $Arctium$ $lappa$ ethanol extract significantly increased in a dose-dependent manner. In the radical scavenging assay using DPPH, the $IC_{50}$ of the Arctium lappa extract was 296 ${\mu}g$/assay(1.29 mg of dry sample). In addition, the $IC_{50}$ in the inhibition of $Fe^{2+}$-induced lipid peroxidation was 1,759 ${\mu}g$/assay(7.65 mg of dry sample). This extract also significantly inhibited the MDA-BSA conjugation reaction with an $IC_{50}$ of 57.58 mg/assay(250 mg of dry sample). However, no inhibitory effects against the direct and indirect mutagenicities in $Salmonella$ Typhimurium TA98 and TA100 were observed. Based on these results, the ethanol extract of $Arctium$ $lappa$ was shown to display considerable antioxidative activities.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.3
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• pp.317-325
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• 2018

This study was carried out to evaluate the antioxidant and whitening activities of Salix gracilistyla extracts. The total polyphenol contents of the extracts were 142.60-151.95 mg GAE/g and total flavonoid contents were 83.43-92.60 mg CE/g. In 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, the 30% methanol extract showed the highest antioxidant activity ($IC_{50}$; $19.68{\mu}g/mL$). Tyrosinase inhibitory activity was similar in all four solvent extracts, and the highest inhibitory activity (35.18%) was obtained at a concentration of $200{\mu}g/mL$ of 30% ethanol extract. In addition, methanol extracts did not affect cell viability at all treatment concentrations and were found to significantly reduce the melanin content of B16F10 cells. As a result, it is considered that Salix gracilistyla extracts can be used as an effective cosmetic ingredient having antioxidant and whitening activity.

• Journal of agriculture & life science
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• v.44 no.2
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• pp.57-66
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• 2010

The antioxidant and neuronal cell protective effects of water extract from purple sweet potato were investigated. The total phenolics and monomeric anthocyanin contents of purple sweet potato extract were 44.25 mg/g and 2,394 mg/L, respectively. The antioxidant activities of purple sweet potato extract were evaluated using various antioxidant tests, including 1,1-diphenyl- 2-picrylhydrazyl (DPPH), 2,2'-azino- bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activities, ferric reducing/antioxidant power (FRAP) and reducing power. In these assays, the extract of purple sweet potato presented significant radical scavenging activities, FRAP, and reducing power in a dose-dependent manner. MTT {3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl- tetrazoliumbromide} reduction assay showed significantly increase in cell viability when PC12 cells were pretreated with purple sweet potato extract. Because oxidative stress is also known to increase neuronal cell membrane breakdown, we further investigated by lactate dehydrogenase (LDH) and neutral red uptake assay. Purple sweet potato extract inhibited oxidative stress-induced membrane damage in neuronal cells. Therefore, these data results demonstrated that water extract of purple sweet potato have antioxidant activity and neuronal cell protective effect thus it has great potential as a natural source for human health.

• Korean Journal of Medicinal Crop Science
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• v.13 no.2
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• pp.85-90
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• 2005

Phytochemical study on the EtOAc fraction from a MeOH extract of the leaves of Alnus hirsuta Rupr. led to the isolation of nine compounds betulin (1), betulinic acid (2), hirsutanonol (3), hirsutenone (4), quercetin (5), avicularin (6), gallic acid (7), hyperin (8), and daucosterol (9). Among them, six compounds 1, 2, 57, and 9 are report from this plant for the first time. All isolated compounds were evaluated for their antioxidant activity using DPPH radical scavenging capacity and inhibition effect on mitochondrial lipid peroxidation. Six phenolic compounds 3-8 were found to have potent antioxidant activity. Of which, compounds 3, 4 and 5 showed significant free radical scavenging activity with the $IC_{50}$ values of $18.3\;{\pm}\;2.5,\;15.7\;{\pm}\;3.8\;and\;23.5\;{\pm}\;3.1\;{\mu}m$, respectively. In addition, the compounds 3-8 exhibited inhibition effect on the mitochondrial lipid peroxidation with the $IC_{50}$ values of $88.0\;{\pm}\;6.5,\;12.6\;{\pm}\;1.2,\;8.0 \;{\pm}\;1.1,\;58.5\;{\pm}\;4.3,\;173.6\;{\pm}\;15.2,\;and\;75.0\; {\pm}\; 6.7\;{\mu}m$, respectively.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.761-765
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• 2009

The effects of probiotic bacteria on the functional properties of squid by-products were investigated during fermentation. Bifidobacterium longum, Lactobacillus acidophilus, Lactobacillus brevis, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus rhamnosus, and Pediococcus acidilactici were used to ferment the squid by-products for 96 hr at $37^{\circ}C$. The numbers of all probiotics increased to $10^7-10^8$ CFU/g after 96 hr fermentation. No substantial pH changes were observed. L. rhamnosus and P. acidilactici showed the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities. Interleukin-6 (IL-6) and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) secreted from B cells increased after adding the extracts of probiotic-fermented squid by-products. The human NK cells were grown well in the B cell-growing broth cultured with the extracts of squid by-products fermented by L. rhamnosus and P. acidilactici. Trimethylamine (TMA) and dimethylamine (DMA) contents were significantly decreased after probiotic-fermentation. Therefore, L. rhamnosus GG and P. acidilactici can be used for the fermentation of squid by-products and their use would provide benefits in functional food products.

• Natural Product Sciences
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• v.20 no.1
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• pp.22-28
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• 2014

A new natural product, tetrastigmol A (1), and several known compounds as flavonoids (2 - 8), steroids (9 - 10), bergenin and its derivative (11 - 12), stilbens (13 - 15), lignan (16), benzenecarboxylic derivative (17) and two norisoprenoid (18 - 19) were isolated from the stem of Tetrastigma erubescens Planch. (Vitateae). Their structures were determined on the basis of NMR spectroscopic data. This is the first report on chemical constituents of this plant. Compounds 1, 6 - 8 and 12 - 15 showed strong antioxidant activity using two methods including DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging and lipid peroxidation inhibitory assays.

• Korean Journal of Pharmacognosy
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• v.30 no.2
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• pp.196-201
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• 1999

Four antioxidative flavonoids were isolated from the aerial parts of Hypericum erectum. Their structures were identified as quercitrin (I), isoquercitrin (Ⅱ), hyperoside (Ⅲ) and orientin (IV) on the basis of spectroscopic means. Antioxidative activities for flavonoids $I{\sim}IV$ were determined by measuring lipid peroxide using 2-thiobarbituric acid (TBA) method and by evaluation the radical scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Compound IV, orientin, was found to have strong antioxidative potency.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.1051-1054
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• 2009

This study was conducted to investigate the antioxidant activity of the extracts of lotus (Nelumbo nucifera Gaertner). The total phenolic contents in leaf, stem, and root were 165, 74, and 30 tannic acid equivalent mg/g of dried extract or fraction respectively. The butanol and ethylacetate fractions of lotus parts showed higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than other fractions. 2,2'-Azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging activity also showed the similar result as the DPPH radical scavenging activity. The antioxidative capacity of the ethylacetate fraction was the highest among fractions and its fraction showed higher contents of total polyphenol.

• Advances in Traditional Medicine
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• v.7 no.2
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• pp.162-170
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• 2007

Woodfordia fruticosa Kurz. (Lythraceae), commonly known as Dhayero, is used in the treatment of various ailments in Nepal. In this study, the antioxidant capacity of crude extract and different polarity fractions of Woodfordia fruticosa flowers were assayed for their scavenging abilities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and nitric oxide radicals, competitive ${\beta}$-carotene bleaching, reducing power, metal chelating ability and total phenolic content. Crude extract and polar fractions showed stronger antioxidant capacity and contained very high level of total phenolics. They exhibited strong DPPH radical scavenging, nitric oxide scavenging and reducing power, medium ${\beta}$-carotene bleaching and poor metal chelating capacity. Positive correlation obtained between total phenolic content and antioxidant capacity assays, indicated the contribution of phenolics toards antioxidant capacity.