• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.276-281
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• 2008

Extracts from Rododendron mucronulatum Turcz. flowers were tested for antioxidant and their inhibitory activities of ${\alpha}$-amylase, ${\alpha}$-glucosidase and angiotensin converting enzyme (ACE). Total contents of phenolics were found as $30.6{\pm}0.14mg/g$ (60% EtOH extract) and $23.2{\pm}0.21mg/g$ (water extract). Electron donation ability (EDA), ABTS [2,2azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] radical decolorization, Antioxidant protection factor (PF) and thiobarbituric acid reactive substance (TBARs) were measured for the antioxidative activity of the extracts from Rododendron mucronulatum Turcz. flowers. The water extract were determined as 97.5% at ethanol extract showed 83.2% and 60% EtOH extract were 89.7% in EDA. The water extract showed higher antioxidant activity than 60% EtOH extract when evaluated by ABTS radical decolorization and antioxidant PF. The TBARS of water extracts and 60% EtOH extracts were shown as $0.29{\times}10^2{\mu}M\;and\;0.28{\times}10^2{\mu}M$, respectively, and were lower than control. ACE inhibitory activity in water extract (67.6% inhibition) was higher than that of 60% EtOH extract (46.7% inhibition) at $200{\mu}g/mL$. Water extracts had higher inhibitory activities on ${\alpha}$-amylase and ${\alpha}$-glucosidase than 60% EtOH extracts. The result suggests that the water extract from Rododendron mucronulatum Turcz. flowers will be useful as natural antioxidants and functional foods.

• 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.

• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.254-260
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• 2015

The effect of the extraction solvent on the physiological properties of the peel of the Korean pear (Pyrus pyrifolia cv. Niitaka) was evaluated. The total phenol content was highest in the 80%(wt) methanol extract, whereas flavonoid content was highest in the 80% ethanol extract. The antioxidant activities of the extracts were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging abilities, and their reducing power. The water and 80% methanol extracts of the pear peel had highest DPPH and ABTS radical scavenging activities, and reducing power, respectively. The inhibition of ${\alpha}$-glucosidase was highest in the 80% methanol extract, and alcohol dehydrogenase activity was highest in the water extract. All three extracts had similar antimicrobial activity. Because water, 80% ethanol, and 80% methanol extracts exhibited high activities in different assays of physiological properties, each solvent could be used for specific purposes.

• Journal of Applied Biological Chemistry
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• v.60 no.2
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• pp.101-108
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• 2017

The phenolic contents which were extracted with water and 70% ethanol from O. undulatifolius were 7.7, 10.1 mg/g, respectively. The 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity of water and ethanol extracts were 78, 82% at $50{\mu}g/mL$ phenolics, respectively. The 2,2'-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization activity were 92, 76% at $100{\mu}g/mL$ phenolics. Antioxidant protection factor in water and ethanol extracts at $200{\mu}g/mL$ phenolics were 1.51 and 2.08 PF, respectively. Thiobarbituric acid reactive substance were 84% in water extracts and 99% in ethanol extracts at $50{\mu}g/mL$ phenolics, respectively. The inhibition activity on ${\alpha}-Glucosidase$ was 44% in ethanol extracts at $200{\mu}g/mL$ phenolics. The inhibition activity on ${\alpha}-amylase$ was 37-88% in water extracts at $50-200{\mu}g/mL$ phenolics. The tyrosinase inhibition activity as whitening effect were 82% in ethanol extracts. The elastase inhibition activity were 4, 61% in water and ethanol extracts, respectively. The collagenase inhibition activity of antiwrinkle effect showed an excellent wrinkle improvement effect as 39% in water extracts and 67% in ethanol extracts at $200{\mu}g/mL$ phenolics, respectively. The hyaluronidase inhibition activity as anti-inflammation effect of ethanol extracts was confirmed to 46% of inhibition at $200{\mu}g/mL$ phenolic. The astringent effect of water and ethanol extracts was confirmed to 13, 32% of effect at $200{\mu}g/mL$ phenolic, respectively.

• The Korean Journal of Food And Nutrition
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• v.29 no.1
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• pp.128-133
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• 2016

This study aimed to evaluate the efficacy of the antioxidative and antidiabetic activities of the flowers, leaves, and roots of the Jerusalem artichoke (Helianthus tuberosus L.). The total polyphenol and flavonoid contents of the leaves were higher than those of the flowers and roots. However, the DPPH radical-scavenging and hydroxyl radical-scavenging activities of the flowers were higher than those of the leaves and roots. The nitrite-scavenging ability under acidic conditions was high in Jerusalem artichoke flower extracts. The ${\alpha}-glucosidase$ inhibitory activity and ${\alpha}-amylase$ inhibitory activity of a methanol extract of Jerusalem artichoke roots were about 60% (5 mg/mL concentration). Based on these experiments, it can be concluded that the flowers leaves, and roots of the Jerusalem artichoke can be used as natural preservatives. Therefore, they can be developed as functional foods, to take advantage of their antioxidant activity and abundant polyphenols. This study suggests that the whole Jerusalem artichoke, including roots, leaves, and flowers, is useful as a functional, nutritious food product.

• Food Science and Preservation
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• v.30 no.2
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• pp.358-368
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• 2023

Euonymus alatus (Thunb.) Sieb., also known as the arrow tree in Korea, is a plant in East Asia used in traditional medicine and food. In particular, the wings of E. alatus are rich in phenolic compounds. This study evaluated the antioxidant, α-glucosidase inhibition, and anti-cancer activities of E. alatus wing extracts. The radical and hydrogen peroxide scavenging acitvities and reducing the power of 1,000 ㎍/mL E. alatus wing extracts, were similar to those of the positive control (0.1% BHT, 0.1% α-tocopherol). In addition, ethanol and methanol extract at 250 ㎍/mL showed 95.70 and 94.99% of α-glucosidase inhibition activity, respectively. The ethanol extract of E. alatus wings had the highest total polyphenol and flavonoid contents (867.8 mg% and 521.7 mg%, respectively). The E. alatus wing extracts significantly decreased the cell viability of LNCaP human prostate cancer cells (p<0.001), MDA-MB-231 human breast cancer cells (p<0.001), and HT-29 human colon cancer cells (p<0.001) in a dose-dependent manner. However, there was no significant effect on B16 mouse melanoma cells. Notably, the ethanol extracts showed higher cancer cell growth inhibitory activity in LNCaP and HT-29 cells than the other extracts. These results suggest that E. alatus wing extracts could have significant clinical applications, and our results can be used as basic data for future functional food material development.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.8
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• pp.989-995
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• 2009

Extract yield of tartary buckwheat treated with water, 70% ethanol or methanol were about 13.6%, 7.0% and 6.6%, respectively. Extract yield was greatly increased by the treatment of $\alpha$-amylase indicating 95.1% yield. $RC_{50}$ value of DPPH radical scavenging activity with methanol and 70% ethanol extracts were 34.0 $\mu g$/mL, 40.5 $\mu g$/mL, respectively. The DPPH radical scavenging activity increased when it was treated with $\beta$-glucosidase and cellulase, showing $RC_{50}$ value of 24.7 $\mu g$/mL and 25.0 $\mu g$/mL, respectively. In ABTS radical scavenging activity, methanol extract (100 $\mu g$/mL) showed 30% inhibition. In DPPH or ABTS radical scavenging activities, the treatment of $\beta$-glucanase and $\alpha$-amylase shows the highest and the lowest activities, respectively. In $\alpha$-glucosidase inhibitory effect, 70% ethanol extract showed $RC_{50}$ value of 59.9 $\mu g$/mL, but water extract was not inhibitory effective. The $\alpha$-glucosidase inhibitory effect was the highest in multi enzyme treatment. Content of rutin and quercetin in methanol extract showed higher value with 4400.3 mg% and 71.9 mg%, respectively. The 70% ethanol extract of buckwheat contained rutin of 3459.8 mg% and quercetin of 56.9 mg%. In the treatment of $\beta$-glucanase, the rutin content of ethanol extract increased with 5057.4 mg% and multi-enzyme treatment resulted in the modification of rutin glycoside.

• Journal of Applied Biological Chemistry
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• v.58 no.4
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• pp.317-323
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• 2015

The extracted phenolic compounds from Cornus kousa fruit for biological activities as functional resources were examined. The phenolic compounds which were extracted with water and 40% ethanol from Cornus kousa fruit were $7.04{\pm}0.27$ and $4.47{\pm}0.18mg/g$, respectively. The 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity of water and ethanol extracts were 84% and 86% at $50{\mu}g/mL$phenolics, respectively. The 2,2'-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid radical decolorization activity of water and ethanol extracts were 84 and 95% at $100{\mu}g/mL$ phenolics, respectively. Antioxidant protection factor in water and ethanol extracts at $50{\mu}g/mL$ phenolics were 1.93 and 1.82 PF, respectively. Thiobarbituric acid reactive substance were 69% in water extracts and 89% in ethanol extracts at $150{\mu}g/mL$ phenolics. The inhibition activity on xanthine oxidase in water and ethanol extracts was 34 and 60%, respectively. The inhibition activity on ${\alpha}$-glucosidase was 29% in water extracts and 87% in ethanol extracts. The tyrosinase inhibitory activity was 19% in ethanol extracts. The collagenase inhibition activity of anti-wrinkle effect showed an excellent wrinkle improvement effect as 53% in water extracts and 77% in ethanol extracts at $200{\mu}g/mL$ phenolics. The hyaluronidase inhibition activity as antiinflammation effect of water extracts was confirmed to 34% of inhibition at $200{\mu}g/mL$ phenolic. The results can be expected extracts from Cornus kousa fruit to use as functional resource for antioxidant, antigout, inhibitor of carbohydrate degradation, antiwrinkle activity and antiinflammation activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.11
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• pp.1508-1514
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• 2012

The purpose of this study was to evaluate the antioxidant contents and antioxidant activities of solvent fractions from methanolic extract of sericea lespedeza. To determine the antioxidant compounds in solvent fractions from methanolic extract, total polyphenolic, flavonoid, tannin, and proanthocyanidin contents were measured by spectrophotometric methods. Solvent fractions were evaluated for antioxidative capacity according to DPPH and ABTS radical scavenging activities. Total polyphenolic contents were 12.44, 3.61, 6.39, 27.11, 20.00, and 9.32 mg gallic acid equivalent (GAE)/g extract residue (ER), respectively. Total flavonoid contents were 2.94, 9.92, 7.77, 9.27, 5.11, and 2.66 mg catechin equivalent (CE)/g ER, respectively. Total tannin contents were 8.75, 10.04, 7.42, 17.32, 11.65, and 7.61 mg tannic acid equivalent (TAE)/g ER, respectively. Total proanthocyanidin contents were 346.09, 63.50, 103.76, 288.62, 231.99, and $358.48{\mu}g$ CE/g ER, respectively. DPPH radical scavenging activities of solvent fractions from methanolic extract of sericea lespedeza were 20.62, 5.16, 9.29, 20.80, 20.00 and 20.79 mg Trolox equivalent (TE)/g ER, and ABTS radical scavenging activities were 33.86, 9.24, 17.36, 33.76, 33.49, and 33.86 mg TE/g ER, respectively. SOD-like activities were 4.12, 0.61, 2.01, 9.89, 13.47, and 11.82 units/mL, and ${\alpha}$-glucosidase inhibition activities were 93.85 and 61.64% at concentrations of 50 and $25{\mu}g/mL$ in the water fraction, respectively. The results of this study show that notable antioxidant activities in sericea lespedeza have significant health benefits.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.2
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• pp.165-172
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• 2015

The objective of this study was to investigate the antioxidant and antiobesity activities of various color resources extracted from natural plants such as, clove, persimmon, gall nut, amur cork, gardenia, safflower, and annatto. Total phenolic content was the highest in gall nut extract (2,441.45 mg/kg) followed by clove extract (1,346.48 mg/kg). DPPH, and ABTS radical scavenging activities and ferric reducing antioxidant power (FRAP) were also higher in gall nut extract. ${\alpha}$-Glucosidase inhibitory activity ($IC_{50}$) was highest in persimmon extract ($22.83{\mu}g/mL$) followed by gall nut extract. ${\alpha}$-Amylase and lipase inhibitory activities were also higher in persimmon extract (49.45% and 61.01%, respectively). Lipid accumulation in 3T3-L1 cells was lower in persimmon, clove, and annatto extracts (81.54%, 83.36%, and 85.70% at $20{\mu}g/mL$, respectively). Triglyceride content in 3T3-L1 cells was lowest in clove extract (66.11%) followed by persimmon extract (88.88%). The results of this study suggest that gall nut extract has the highest antioxidant activity, whereas persimmon and clove extract show the antiobesity activities by inhibition of digestive enzymes and fat accumulation in 3T3-L1 cells. These extracts are useful materials for the development of antioxidant and antiobesity functional foods.