• BMB Reports
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• v.44 no.6
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• pp.410-414
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• 2011

Chana series are new chalcone derivatives. To evaluate the possibility of Chana series as therapeutic agents of type 2 diabetes, the inhibitory effects of Chana series on the activities of ${\alpha}$-glucosidase and DPP-4 were investigated using in vitro enzyme assays, and their effects on adipocyte differentiation were investigated in C3H10T1/2 cells. Chana 1 and Chana 7 among the Chana series showed significant inhibition of ${\alpha}$-glucosidase activity. In DPP-4 enzyme assay, Chana 1 exhibited the highest inhibitory activity while Chana 7 did not. In MTT assay, Chana 1 did not show significant cytotoxicity up to a concentration of $250{\mu}M$, whereas cytotoxicity was observed with Chana 7 at a concentration of $300{\mu}M$. In addition, Chana 1 induced adipocyte differentiation. Therefore, Chana 1 showed inhibitory effects on ${\alpha}$-glucosidase and DPP-4 as well as a stimulatory effect on adipocyte differentiation, suggesting that Chana 1 may be a potential beneficial agent for the treatment of type 2 diabetes.

• Preventive Nutrition and Food Science
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• v.20 no.2
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• pp.88-93
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• 2015

The purpose of this research was to investigate the inhibitory effect of jicama extract on ${\alpha}$-glucosidase activity, ${\alpha}$-amylase activity, and postprandial hyperglycemia in streptozotocin (STZ)-induced diabetic mice. Jicama extract showed prominent inhibitory effects against ${\alpha}$-glucosidase and ${\alpha}$-amylase. The $IC_{50}$ values of jicama extract against ${\alpha}$-glucosidase and ${\alpha}$-amylase were $0.083{\pm}0.004$ and $0.091{\pm}0.017mg/mL$, respectively. The increase in postprandial blood glucose levels was more significantly suppressed in the jicama extract-administered group than in the control group of both STZ-induced diabetic and normal mice. Blood glucose levels of the control group increased to $383.75{\pm}11.54$ and $402.50{\pm}15.32mg/dL$ at 30 and 60 min after a meal and decreased to $349.67{\pm}11.62mg/dL$ at 120 min. However, postprandial blood glucose levels were significantly decreased, when diabetic mice were fed with jicama extract ($342.00{\pm}15.73$, $367.00{\pm}13.00$, and $329.67{\pm}12.43mg/dL$ at 30, 60, and 120 min, respectively). Furthermore, the area under the curve was significantly decreased with jicama extract administration in diabetic mice (P<0.05). Therefore, these results indicate that jicama extract may help decrease postprandial blood glucose level by inhibiting ${\alpha}$-glucosidase.

• Journal of the Korean Society of Food Culture
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• v.23 no.4
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• pp.479-488
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• 2008

Some biological activities such as an electron donating capacity, the contents of total polyphenol compounds and flavonoids, fibrinolytic activity and $\alpha$-glucosidase inhibitory activity have been detected in hot water extracts of Ligularia fischeri and Angelica gigas Nakai. To increase the usefulness of the functional ingredients for prevention and improvement of some metabolic disorders, ethanol-treated hot water extracts of Angelica gigas Nakai were prepared. A hot water extract of Ligularia fischeri has 92% of electron donating capacity, 39.4 mg/g of total polyphenol compounds, 24.8 mg/g of flavonoids and 29.8% of $\alpha$-glucosidase inhibitory activity, but no fibrinolytic activity. A hot water extract of Angelica gigas Nakai has 94.7% of electron donating capacity, 5.8 mg/g of total polyphenol compounds, 2.6 mg/g of flavonoids, 0.48 plasmin units of fibrinolytic activity and no $\alpha$-glucosidase inhibitory activity. However, with partial purification using cold ethanol treatment, the $\alpha$-glucosidase inhibitory activity of Angelica gigas Nakai was increased to 70.5%. Thus, we expected a more useful effect with the use of the addition of a cold ethanol-treated Angelica gigas Nakai extract. The L, b values of cold buckwheat noodles using a mixture of 0$\sim$3% of Ligularia fischeri powder and 0.5% of an ethanol-treated hot water extract of Angelica gigas Nakai were decreased with the addition of an increasing amount of Ligularia fischeri powder. Among the mechanical qualities, only adhesiveness was significantly higher in 3% Ligularia fischeri noodles. From sensory evaluation data, it was determined that these two functional ingredients did not ruin the color, texture, and overall acceptance of the cold buckwheat noodles. A higher amount of the extracts improved the quality of the product with little added cost.

• Korean Journal of Food Science and Technology
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• v.40 no.5
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• pp.558-561
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• 2008

Culture broth of Bacillus subtilis Y3-7 in tryptic soy broth (TSB) isolated from Korean traditional fermented food was evaluated for the inhibition of $\alpha$-glucosidase. The results of in vitro studies using the yeast $\alpha$-glucosidase demonstrated that the culture broth exerted inhibitory effects on $\alpha$-glucosidase with $IC_{50}$ value of 1.62 mg/mL, and functioned as a competitive inhibitor. Furthermore, the culture broth of B. subtilis Y3-7 significantly improved glucose tolerance in normal and streptozotocin-induced diabetic mice. The blood glucose levels in the mice receiving sucrose supplementation in the culture broth (1 g/kg, 2 g/kg) were measured at 48.7%, which corresponded to 22.2% of the levels measured in the control mice. These results indicated that the culture broth of B. subtilis Y3-7 in TSB might be considered as a useful compound for the preparation of functional foods for diabetic patients.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.4
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• pp.481-486
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• 2010

The nutraceutical role of omija (Schizandra chinensis Baillon) water extract (OWE) was determined through the analysis of antioxidant activity, nitrite scavening activity, and xanthine oxdiase and $\alpha$-glucosidase inhibitory effects. Antioxidant activity of OWE was measured by using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical scavenging activity and superoxide dismutase-like activity (SODA). DPPH radical scavenging activity and SODA increased in a dose-dependent manner, and was about 49.0% at 2.5 mg/mL and 69.2% at 5 mg/mL, respectively. The xanthine oxidase and $\alpha$-glucosidase inhibitory activities of OWE were about 88.8% and 86.2% at 1 mg/mL, respectively. Nitrite scavenging activity of OWE was about 54.9%, 42.4%, and 34.2% on pH 1.2, 3.0, and 6.0 at 1 mg/mL, respectively. These results suggest that OWE has a strong antioxidant activity, and xanthine oxidase and $\alpha$-glucosidase inhibitory effects.

• Journal of Life Science
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• v.22 no.10
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• pp.1420-1427
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• 2012

We investigated the physiological activity and solvent-partitioned fractions of methanol extracts from the green seaweed Sargassum fulvellum. The methanol extract from S. fulvellum was sequentially fractionated with n-hexane (SFMH), methanol (SFMM), buthanol (SFMB), and water (SFMA). We investigated the antioxidant activities of solvent fractions from S. fulvellum by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and an SOD activity assay. DPPH radical scavenging capacity of SFMM was 79.5% at 10 mg/ml. SOD activity of SFMM was 79.9% at 10 mg/ml. Nitrite scavenging activities of solvent fractions from S. fulvellum were investigated under different pH conditions and showed the most remarkable effect at pH 1.2. In particular, the activity of SFMB was higher than the other fractions. ADH activity and ALDH activity of SFMM were 177.0% and 167.4% at 10 mg/ml, respectively. ${\alpha}$-Glucosidase inhibitory activity of SFMH increased in a dose-dependent manner and was about 94.1% at 2 mg/ml. Elastase inhibitory activity was 93.2% at 2 mg/ml. These results revealed that S. fulvellum extracts have strong antioxidant and alcohol dehydrogenase activities and ${\alpha}$-glucosidase inhibitory activity, suggesting that S. fulvellum extracts have potential as a source of natural products for health and beauty.

• Food Science and Preservation
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• v.21 no.4
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• pp.460-467
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• 2014

This study was conducted to investigate the effect of the addition of Hizikia fusiforme, Capsosiphon fulvescens, and Undaria pinnatifida sporophyll on the antioxidant and inhibitory potentials against key enzymes related to type 2 diabetes of a commercial vegetable extract. The nutritional quality and mineral concentration of a vegetable extract with seaweeds added were also analyzed. The addition levels of seaweed did not influence the proximate composition, whereas the calcium, sodium, potassium, magnesium, and iron concentrations significantly increased at the 5% Hizikia fusiforme and Undaria pinnatifida sporophyll addition levels. The 20% Hizikia fusiforme addition level significantly increased the total phenolic content and reducing power by 47.08% and 16.82%. The hydroxyl radical scavenging ability of the vegetable extract was not strengthened with the addition of seaweeds. The DPPH radical scavenging activity at the 20% Hizikia fusiforme, Capsosiphon fulvescens, and Undaria pinnatifida sporophyll addition levels significantly increased by 27.47%, 22.25%, and 17.27%, respectively. The vegetable extract with seaweeds added showed higher-level ${\alpha}$-glucosidase inhibition activities, accompanied by relatively weaker ${\alpha}$-amylase inhibition activity. In particular, at the 5% Undaria pinnatifida sporophyll addition level, the ${\alpha}$-glucosidase activity was significantly inhibited by 98.26%. Overall, the results showed that the incorporation of seaweeds into a vegetable extract effectively increased the mineral concentration and improved the antioxidant and inhibitory abilities of the extract on key enzymes linked to type 2 diabetes.

• Archives of Pharmacal Research
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• v.20 no.4
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• pp.346-350
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• 1997

The synthesis of cis- and trans-1,6-dihydroxypyrrolizidine starting from trans-4-hydroxy-L-proline and their evaluation as glycosidase inhibitors are reported. The cis-isomer was found to be a potent inhibitor against .alpha.-glucosidase and showed weak inhibitory effect against other glycosidases. The trans-isomer exhibited weak inhibitions of b-glucosidase and amylo-glucosidase and poor inhibition of other glycosidases.

• Nutrition Research and Practice
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• v.1 no.3
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• pp.184-188
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• 2007

The major goal in the treatment of diabetes mellitus is to achieve near-normal glycemic control. To optimize both fasting blood glucose and postprandial glucose levels is important in keeping blood glucose levels as close to normal as possible. ${\alpha}-Glucosidase$ is the enzyme that digests dietary carbohydrate, and inhibition of this enzyme could suppress postprandial hyperglycemia. The purpose of this study was to test the inhibitory activity of methanol extract of Euonymus alatus on ${\alpha}-glucosidase$ in vitro and in vivo to evaluate its possible use as an anti-diabetic agent. Yeast ${\alpha}-glucosidase$ inhibitory activities of methanol extract of E. alatus were measured at concentrations of 0.50, 0.25, 0.10, and 0.05 mg/ml. The ability of E. alatus to lower postprandial glucose was studied in streptozotocin-induced diabetic rats. A starch solution (1 g/kg) with and without E. alatus extract (500 mg/kg) was administered to diabetic rats by gastric intubation after an overnight fast. Plasma glucose levels were measured at 30, 60, 90, 120, 180, and 240 min. Plasma glucose levels were expressed in increments from baseline, and incremental areas under the response curve were calculated. Extract of E. alatus, which had an $IC_{50}$ value of 0.272 mg/ml, inhibited yeast ${\alpha}-glucosidase$ activity in a concentration-dependent manner. A single oral dose of E. alatus extract significantly inhibited increases in blood glucose levels at 60 and 90 min (p<0.05) and significantly decreased incremental response areas under the glycemic response curve (p<0.05). These results suggest that E. alatus has an antihyperglycemic effect by inhibiting ${\alpha}-glucosidase$ activity in this animal model of diabetes mellitus.

• 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.