• Food Science and Preservation
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• v.20 no.6
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• pp.877-885
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• 2013

Wine extracts of four different berry fruits, such as mulberry, blueberry, strawberry, and raspberry, were investigated for antioxidant, anti-tyrosinase, and ${\alpha}$-glucosidase activities by using in vitro assays. Additionally, quantitative changes of ${\alpha}$-glucosidase inhibitor in mulberry wine were determined by HPLC according to mulberry cultivars and fermentation process. Among four berry wines examined, mulberry wine showed the most potent ${\alpha}$-glucosidase inhibitory activity with 69.37% at 0.23 mg/mL, while blueberry and strawberry wines exhibited the strongest inhibition against DPPH radical and tyrosinase activity, respectively. Four compounds were isolated and purified from mulberry wine by a series of isolation procedures, such as solvent fractionation, and Diaion HP-20, ODS-A, and Sephadex LH-20 column chromatographies. Among them, Comp. 4 exerted the strongest ${\alpha}$-glucosidase inhibitory activity ($I_C_{50}=31.57{\mu}M$), and its chemical structure was identified as quercetin by UV and NMR spectral analysis. Finally, the "Daeseongppong" (16.83 ppm) muberry wine had larger amount of quercetin than the "Iksuppong" (14.85 ppm) and "Cheongilppong" (8.92 ppm) mulberry wines, but their contents of three mulberry wines decreased considerably with aging process. These results suggest that mulberry wine containing quercetin acted as ${\alpha}$-glucosidase inhibitor may be useful as a potential functional wine for improving diabetic disorder.

• 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 Dairy Science and Biotechnology
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• v.35 no.4
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• pp.221-231
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• 2017

This study aimed to investigate the physiological characteristics and anti-obesity effects of a newly isolated bacterium, Lactobacillus plantarum K6. L. plantarum K6 showed good ${\alpha}-amylase$ inhibitory activity ($96.78{\pm}3.29%$), ${\alpha}-glucosidase$ inhibitory activity ($92.55{\pm}9.62%$), and lipase inhibitory activity ($85.17{\pm}0.79%$), and the strain inhibited the adipocyte differentiation of 3T3-L1 cells ($27.4{\pm}1.4%$) when present at a concentration of $100{\mu}g/mL$. L. plantarum K6 was isolated from kimchi and its physiological characteristics were investigated. A comparison of the sensitivity of the isolate to 15 different antibiotics showed that L. plantarum K6 is highly sensitive to erythromycin and highly resistant to vancomycin, ampicillin, and polymyxin B. This strain also showed high arylamidase and ${\beta}-galactosidase$ activities. Moreover, it was relatively tolerant to bile acid and low pH, and displayed resistance to Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus, with rates of 51.8%, 42.4%, 61.6%, and 54.9%, respectively. No bio genic amines were produced. L. plantarum K6 also showed high adhesion activity to HT-29 cells compared to L. rhamnosus GG. These results demonstrate that Lactobacillus plantarum K6 has potential as a probiotic with anti-obesity effects.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.1
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• pp.101-108
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• 2014

This study was conducted in order to compare the biological activities of water extracts and sugar immersion extracts of green pepper (Capsicum annuum L.), purslane (Portulaca oleracea L.) and shiitake (Lentinula edodes (Berk.) Pegler) by measuring total polyphenol and flavonoid contents, antioxidant activities and inhibitory effects on ${\alpha}$-amylase and ${\alpha}$-glucosidase. The contents of total polyphenols and flavonoids were higher in water extracts than in sugar immersion extracts. The anti-oxidative activities of water and sugar immersion extracts were measured using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity assay and reducing power assay. All extracts scavenged radicals in a concentration-dependent manner, and water extracts showed stronger radical scavenging activity and reducing power than sugar immersion extract. However, they all exhibited lower activities than ascorbic acid. Compared to the anti-diabetic drug acarbose, which was used as a positive control, the two types of extracts exhibited low ${\alpha}$-glucosidase inhibitory activities, although the activity of sugar immersion extracts were 2-fold higher than that of water extracts. ${\alpha}$-Amylase inhibitory action was not observed for any of the extracts. Finally, by cytotoxicity test, we confirmed that sugar immersion extracts were safer than water extracts. These results indicate that water extracts and sugar immersion extracts of green pepper, purslane and shiitake have different advantages in terms of their antioxidant and anti-diabetic effects, respectively.

• Applied Biological Chemistry
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• v.49 no.1
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• pp.77-81
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• 2006

This study was carried out to investigate the chemical components, and antioxidative and $anti-{\alpha}-glucosidase$ activities of Equisetum arvense extracts. In Equisetum arvense extracts were composed of 53.20% of crude fiber, 20.42% of crude ash, 15.32% of crude protein and 2.21% of crude fat. Potassium was the most predominant mineral and followed by phosphorus, calcium, magnesium, and sodium. The contents of the unsaturated fatty acids, such as linolenic acid, linoleic acid, and palmitic acid, were higher than those of saturated fatty acids. Seventy percent ethanol extract exhibited antioxidative activity with $IC_{50}$ of $168.1\;{\mu}g/ml$. The Seventy percent methanol extract showed higher ${\alpha}-glucosidase$ inhibitory activity than other solvent extracts.

• Korean Journal of Medicinal Crop Science
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• v.21 no.4
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• pp.301-305
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• 2013

This study was performed to select adequate plant materials for developing a natural ${\alpha}$-glucosidase inhibitor by analyzing ${\alpha}$-glucosidase inhibition activity in fronds and rhizomes of three Dryopteridaceae species: Cyrtomium fortunei, Polystichum polyblepharum, and P. lepidocaulon. The highest ${\alpha}$-glucosidase inhibitor obtained from frond of P. lepidocaulon ($4.16{\mu}g{\cdot}mL^{-1}$), and rhizome of C. fortunei ($1.84{\mu}g{\cdot}mL^{-1}$), showed much higher inhibition activity than acarbose ($1413.70{\mu}g{\cdot}mL^{-1}$). The biomass required to inhibit ${\alpha}$-glucosidase by 50% was 0.04 ~ 0.35mg for frond and 0.03 ~ 0.10mg for rhizome, and P. lepidocaulon required the least amount of fronds and P. lepidocaulon the least rhizomes. In frond, ${\alpha}$-glucosidase inhibition activity was the highest in water fraction of C. fortunei ($20.2{\mu}g{\cdot}mL^{-1}$), and n-butanol fraction of P. lepidocaulon ($9.33{\mu}g{\cdot}mL^{-1}$) and P. polyblepharum ($5.10{\mu}g{\cdot}mL^{-1}$). In rhizome, it was the highest in n-butanol fractions of C. fortunei ($19.76{\mu}g{\cdot}mL^{-1}$) and P. polyblepharum ($4.47{\mu}g{\cdot}mL^{-1}$), and ethylacetate fraction of P. lepidocaulon ($5.46{\mu}g{\cdot}mL^{-1}$). The frond biomass required for 50% ${\alpha}$-glucosidase inhibition was the lowest in the water fraction of C. fortunei (1.43mg), and n-butanol fractions of P. lepidocaulon (1.10mg) and P. polyblepharum (0.66mg). The required biomass of rhizome was the lowest in the water fraction of C. fortunei (1.59mg), and n-hexane fractions of P. lepidocaulon (0.04mg) and P. polyblepharum (0.15mg). The result of this study suggested that the three Dryopteridaceae species had high ${\alpha}$-glucosidase inhibition activity with small biomass, which might have high value as materials for economical anti-diabetic medication.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.571-577
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• 2010

Korean traditional medicinal herbs have been reported to possess antioxidant and anti-hyperglycemic activities. We tested the antioxidant and anti-hyperglycemic activities of 6 kinds of medicinal herbs: Angelica gigas N., Poria cocos, Mori radicis Cortex, Mori folium, Aralia elata Cortex, and Panax ginseng, prepared as hot water, ethanol, and sonication extracts. The antioxidant activities of the extracts were examined by performing total polyphenol, total flavonoid, and ${\alpha}$,${\alpha}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) assays. For M. folium, the ethanol extract showed the strongest effects in DPPH radical scavenging activity among the three extraction methods. In addition, sonication extracts of M. radicis Cortex and M. folium showed the highest inhibitory activities for ${\alpha}$-glucosidase among the different extracts. The ethanol extracts of M. folium had the highest inhibition effects against ${\alpha}$-amylase. A direct correlation between antioxidant and anti-hyperglycemic inhibition activity was found in the ethanol and sonication extracts. From the results, it is considered that these six medicinal herbal extracts have antioxidative, anti-hyperglycemic, and correlation effects based on different extraction methods.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.806-813
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• 2013

Agrimonia pilosa Ledeb. is a medicinal plant with anti-tumor, anti-oxidant, anti-inflammatory and anti-hyperglycemic activities. However, few studies of the anti-diabetic effect of A. pilosa on insulin resistance status have been performed. In the present study, the anti-diabetic effect of A. pilosa water extract (AP) was determined by investigating its ${\alpha}$-glucosidase inhibitory property, glucose utilization, and uptake, as well as insulin resistance mechanism of action in C2C12 skeletal muscle cells. Compared to positive control (acarbose), AP ($10mg/m{\ell}$) showed a similar ${\alpha}$-glucosidase inhibitory capacity. Glucose uptake was significantly increased by $1{\mu}m$ insulin treatment (p<0.05). However, palmitic acid (FFA, 1 mM) induced muscle insulin resistance and glucose uptake dysfunction. On the other hand, AP ($10{\mu}g/m{\ell}$) was capable of reversing the FFA-induced insulin resistance in C2C12 myotubes. Compared to control, AP ($100{\mu}g/m{\ell}$ without insulin) significantly increased the utilization of glucose (p<0.05) in C2Cl2 myotubes cultured in normal glucose (7 mM). AP treatment significantly increased the relative mRNA and protein expression levels of Akt. In particular, the effect of A. pilosa on the insulin signaling system is associated with the up-regulation of Akt genes and glucose uptake in C2Cl2 myotubes. These results suggest that A. pilosa is useful in the prevention of diabetes and the treatment of hyperglycemic disorders.

• Journal of Life Science
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• v.28 no.6
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• pp.688-696
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• 2018

Hemp seed (Cannabis sativa L.; HS), an annual herbaceous plant in the Cannabis genus, has been reported to play various biological functions in immunity increase, atherosclerosis, constipation, hyperlipidemia prevention, anti-inflammatory, and anti-cancer. In recently years, as superfood, the growing interest in the health care benefits of hemp seed has led to increased consumption. In this study, we investigated the effect of an ethanol extract of HS fermented with lactic acid bacteria (Lactobacillus plantarum KCTC 3107, L. plantarum KCTC 3108, L. brevis BHN-LAB128, L. paracasei BHN-LAB129). An antibacterial activity against Staphylococcus aureus and Bacillus cereus were 13.99 mm and 15.17 mm, respectively. The ethanol extracts of fermented hemp seed by lactic acid bacteria that the contents of total polyphenol, total flavonoid content, DPPH radical scavenging activity, SOD-like activity, and ${\alpha}$-glucosidase inhibitory activity were increased compared to non-fermented hemp seed. Also, tyrosinase inhibitory activity of the fermented hemp seed (FHS), known to melanin increasing substance was increased. In these results, we suggested that FHS have effects of anti-oxidant, ${\alpha}$-glucosidase inhibitory activity, and tyrosinase inhibitory activity. Hence, we proposed that FHS has possible to development as functional foods and cosmetics.

• Journal of Life Science
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• v.27 no.1
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• pp.32-37
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• 2017

Cyanidin-3-O-glucoside (C3G) shows anti-inflammatory and antioxidant effects; however, its effect on postprandial blood glucose levels remains unknown. Alpha-glucosidase inhibitors regulate post-prandial hyperglycemia by impeding carbohydrate digestion in the small intestine. Here, the effect of C3G on ${\alpha}-glucosidase$ and ${\alpha}-amylase$ inhibition and its ability to ameliorate postprandial hyperglycemia in streptozotocin (STZ)-induced diabetic mice were evaluated. ICR normal and STZ-induced diabetic mice were orally administered soluble starch alone or with C3G or acarbose. The half-maximal inhibitory concentrations of C3G for ${\alpha}-glucosidase$ and ${\alpha}-amylase$ were 13.72 and $7.5{\mu}M$, respectively, suggesting that C3G was more effective than acarbose. The increase in postprandial blood glucose levels was more significantly reduced in the C3G groups than in the control group for both diabetic and normal mice. The area under the curve for the diabetic mice was significantly reduced following C3G administration. C3G may be a potent ${\alpha}-glucosidase$ inhibitor and may delay dietary carbohydrate absorption.