• The Korean Journal of Food And Nutrition
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• 제25권2호
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• pp.246-252
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• 2012

After a mixed carbohydrate diet, inhibition of ${\alpha}$-amylase and ${\alpha}$-glucosidase involved in the digestion and absorption of carbohydrates can significantly decrease the postprandial increase of blood glucose level. In the course of screening these useful enzyme inhibitors, we selected five kinds of bean, using an in-vitro enzyme inhibition assay method. To evaluate the effect of germination process on the functionality of the bean, we investigated the inhibitory activities of the water extracts of non-germinated bean and germinated bean against ${\alpha}$-amylase and ${\alpha}$-glucosidase, relevant to postprandial hyperglycemia. We also investigated the oxygen radical absorbance capacity(ORAC), total phenolics content, and postprandial blood glucose lowering effect in rats(Sprague-Dawley rat model). Most germinated beans showed significantly higher ${\alpha}$-glucosidase inhibitory activity, compared with non-germinated beans. Among germinated beans, Glycine max had the highest ${\alpha}$-glucosidase inhibitory activity(53.3%). The water extract of germinated Phaseolus vulgaris L. had the highest ${\alpha}$-amylase inhibitory activity(95.1%), followed by Glycine max(58.7%), and Glycine max L. Merr(54.1%). Furthermore, the five germinated beans also showed high antioxidant activities in ORAC assay. Results suggested that the germination process may improve and enhance the anti-hyperglycemia potential and antioxidant activity of the bean.

• Journal of Life Science
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• 제22권6호
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• pp.751-759
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• 2012

Microbulbifer sp. was used to acquire the degrading products from Ecklonia cava (DPEC) and the products were investigated to determine the physiological activities. Firstly, 2,2-diphenyl-1-picrylhydrazyl (DPPH) activity and superoxide dismutase (SOD) assay were about 84.1% and 89.6% at 2.5 mg/ml, respectively. In addition, nitrite scavenging ability was shown to be 56.3% at 0.5 mg/ml on pH 1.2. ${\alpha}$-Glucosidase inhibitory activity was increased in a dose-dependent manner and was about 58.7% at 2.5 mg/ml. To determine the influence of DPEC on alcohol metabolism, the generating activity of reduced-nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) were measured. Facilitating rates of ADH and ALDH activities by DPEC were 123.3% and 215.2% at 2.5 mg/ml, respectively. For analyses of anti-wrinkling and whitening effects, its elastase and tyrosinase inhibitory activities were measured and were about 73.1% and 42.2% at 2.5 mg/ml, respectively. These results indicated that DPEC has valuable biological attributes owing to its antioxidant, nitrite scavenging, and alcohol metabolizing activities and ${\alpha}$-glucosidase, elastase, and tyrosinase inhibitory activities.

• Journal of the Korean Society of Food Science and Nutrition
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• 제37권5호
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• pp.542-547
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• 2008

The anti-diabetic effects of water extracts (WE) from medicinal herbs on hepatic glucose-regulating enzymes, such as glucokinase (GCK), pyruvate dehydrogenase (PDH), acetyl-CoA carboxylase (ACC) and ${\alpha}$-glucosidase, were studied using the cytosol fraction in liver and mitochondia fraction in heart of a type II diabetic animal (GK rat, Goto-Kakizaki). The free radical scavenging activity of water extracts by DPPH method was also tested. We found that free radical scavenging activity was strong in Corni fructu (CF), Mokdan Bark (MDB), Chenhwabon (CHB) and Sanyack (SY), while that of Backbocreng (BBR), Shuckgihwang (SGH) and Taecsa (TS) was lower. For GCK activity in cytosol of liver, CF and CHB had a more effective activity than other extracts. PDH activity in mitochondria fraction of heart was higher in all of the extracts, expect for the TS extract, than in the control. ACC activity in cytosol fraction of liver was significantly higher in the CF, CHB, SGH, TS and SY extracts than in the control. CF, BBR and MDB led to a decrease in the ${\alpha}$-glucosidase activity. Therefore, these results suggest that all of the extracts may be used as functional material in the development as anti-diabetic functional food and medicine.

• Journal of Life Science
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• 제30권1호
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• pp.18-25
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• 2020

This study was designed to investigate whether Loranthus parasiticus extract (LPE) could inhibit the activities of carbohydrate digestive enzymes and alleviate postprandial hyperglycemia in diabetic mice. Lyophilized L. parasiticus was extracted with 80% ethanol and concentrated. The inhibitory effects of LPE on carbohydrate digestive enzymes were evaluated by examining α-glucosidase and αamylase, and it was seen to inhibit the activities of both enzymes in a dose-dependent manner. More specifically, the IC50 values of LPE against α-glucosidase and α-amylase were 0.121±0.007 and 0.157±0.004 mg/ml, respectively, significantly lower than those of acarbose, showing that LPE has stronger inhibitory effects than the positive control. These results suggest that LPE strongly inhibits the activities of these digestive enzymes. Blood glucose levels in the control group of diabetic mice increased to 490.00±28.52 mg/dl and 474.60±25.30 mg/dl at 60 and 120 min after a meal, respectively. However, when LPE was added to starch, postprandial blood glucose levels were significantly reduced (463.0±23.73 and 418.5±24.50 mg/dl at 60 and 120 min, respectively; p<0.05). The area under the curve also significantly decreased following administration of LPE, with no cytotoxicity. These results therefore indicate that LPE could be used as an α-glucosidase and α-amylase inhibitor and delay carbohydrate digestion and, thus, glucose absorption after a meal.

• Journal of the Korean Society of Food Science and Nutrition
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• 제46권11호
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• pp.1308-1315
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• 2017

This study was conducted to develop Momordica charantia L. juice fermented by four Lactobacillus species such as Lactobacillus paracasei (LPA), Lactobacillus plantarum (LPL), Lactobacillus rhamnosus (LRH), and Lactobacillus reuteri (LRE) as well as to investigate their inhibitory effects against digestive enzymes and antioxidant activities. Fermentation was performed at $37^{\circ}C$ without nutrient supplementation for 72 h. The pH and total lactic acid contents were within the ranges of 3.75~3.96 and 5.21~10.04% in fermented juices, respectively. The type of starter culture and fermentation time induced changes in flavonoid contents more than total phenolic contents. All juices fermented for 48 h strongly inhibited ${\alpha}$-glucosidase activity with the percentage of inhibition ranging of 91.24~95.05%. Antioxidant activities of all juices mostly increased after 48 h of fermentation. Our results suggest that fermented juice possesses inhibitory activity against digestive enzymes and antioxidant activity, and they can be used as health functional beverages.

• Korean Journal of Medicinal Crop Science
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• 제11권1호
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• pp.5-12
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• 2003

The biological activities of extracts from Rubus coreanus Miq. were compared. About 70% of the growth of human hepatocarcinoma and 79% of human gastric cancer cell was inhibited in adding 1.0 mg/ml of the extracts of Rubus coreanus Miq. respectively. The growth of human breast cancer cells was also inhibited in adding 1.0 mg/ml of the extracts as well as 78% of the human cancer cells. It was proved that the growth of human normal lung cell, scored as 15% for the extracts. Overall selectivity of the extracts on several human cancer cell line was over 5, which is higher than those from the Rubus coreanus Miq. The growth of both human immune B and T cells was enhanced up to 1.4 to 1.8 times by adding the extracts, compared to the controls. The secretion of tumor necrosis $factor-alpha(TNF-{\alpha})$ from T cell was also increased up to 78.8 pg/ml in adding the ethanol extract (0.5 mg/ml). Ethanol extract also increased up to about 70 pg/ml of interleukin-6(IL-6) from B cell. For screening regulate function of blood pressure, angiotensin converting enzyme(ACE) activity was inhibited up to 25% by adding the ethanol extract (1.0 mg/ml). In testing the hypoglycemic activity, 20% of ${\alpha}-glucosidase$ activity was inhibited for the extracts (0.5 mg/ml). GST activity was increased in the range of 1.2 to 1.6 times by adding extracts.

• Korean Journal of Medicinal Crop Science
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• 제22권4호
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• pp.289-294
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• 2014

Maesa japonica (Thunb.) is an evergreen shrub belonged to the Myrsinaceae family, which was discovered in 2006 in South Korea. And, its biological functions have not been well studied. In this study, we determined the antioxidant activities, ${\alpha}$-glucosidase inhibitory effects and antimicrobial activities of methanol extract and the solvent fractions of M. japonica leaves and twigs. The highest antioxidant activity obtained by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging assay and reducing power assay was found in the ethylacetate fraction of twigs methanol extract, which contained the highest level of total phenolic compounds compared to the other fractions. In addition, ethylacetate fraction of twigs extract exhibited higher inhibitory activities against ${\alpha}$-glucosidase ($IC_{50}=0.8{\mu}g/m{\ell}$) compared to the $IC_{50}$ of the buthanol fraction ($IC_{50}=16{\mu}g/m{\ell}$) of leaves extract. It showed antimicrobial activities against Bacillus atrophaeus and Bacillus subtilis subsp. Spizizenii. Although the data is too limited, the current study is the first report on biological functions of M. japonica.

• Journal of the Korean Society of Food Science and Nutrition
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• 제38권11호
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• pp.1528-1534
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• 2009

This study was designed to evaluate the anti-obesity and hypoglycemic effects of Gugija (Lycium chinense Mill) extracts in 3T3-L1 adipocytes. We investigated the $\alpha$-amylase and $\alpha$-glucosidase inhibitory activities of extracts from Gugija. Gugija was extracted by 70% EtOH and 80% MeOH and aqueous, respectively. A single oral dose of Gugija extract inhibited the increase of blood glucose levels significantly at 0, 30, 60, 90 and 120 min and decreased incremental response areas under the glycemic response curve. These results suggest that Gugija 70% EtOH extracts may delay carbohydrate digestion and reduce postprandial hyperglycemia. In addition, triglyceride content in 3T3-L1 adipocytes decreased at higher concentrations of Gugija 70% EtOH extract. Free fatty acid content in 3T3-L1 adipocytes was increased at higher concentrations of Gugija 70% EtOH extract. Also, glucose transporter 4 (GLUT4), the key insulin signaling pathway transcription factor, was remarkably increased by the Gugija 70% EtOH extract when compared to those of control cells in protein expression levels. Therefore, Gugija can be developed as an effective anti-obesity and hypoglycemic agent.

• Korean Journal of Plant Resources
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• 제30권4호
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• pp.352-363
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• 2017

To investigate skin-whitening effect of Adenophora triphylla var. japonica sprout extract, antioxidant activity, inhibitory effect on tyrosinase and melanin synthesis in B16/F10 melanoma cell were examined. Total phenolic content (246.25 mg GAE/g) and total flavonoid content (303.94 mg RE/g) of ethyl acetate fraction from Adenophora triphylla sprout (EFAT) showed the highest contents than other fractions (n-hexane, chloroform and distilled water). Antioxidant activities of EFAT has been evaluated using ABTS, DPPH radical scavenging activities, FRAP and inhibitory effect of lipid peroxidation. EFAT showed excellent radical scavenging activity and inhibitory effect on MDA production. Inhibitory effect of tyrosinase as a major enzyme of melanin synthesis was also measured. In these results, EFAT showed higher inhibitory effect against L-DOPA (51.27%) than L-tyrosine. $IC_{50}$ value on ${\alpha}-glucosidase$ was $41.93{\mu}g/ml$. In B16/F10 melanoma cells, EFAT inhibited melanin synthesis at $200{\mu}g/ml$ concentration (about 42% decrease). Finally, main physiological compounds of EFAT were identified as a rutin and a chlorogenic acid using high performance liquid chromatography.

• Journal of the Korean Society of Food Science and Nutrition
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• 제40권2호
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• pp.163-170
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• 2011

The nutritional properties and biological activities of leaves and stems of Gaeddongssuk (Artemisia annua L.) were investigated. Contents of moisture, crude lipid and crude protein were significantly higher in the leaves, and then ash, crude fiber and mineral were significantly higher in the stems. Contents of total phenols and flavonoids of leaves were about 2 fold higher than those of stems. Antioxidant activity was significantly increased in a dose-dependent manner; also, water and ethanol extracts of leaves were stronger than those of stems. Especially, DPPH radical scavenging activity, reducing power and tyrosinase inhibition activity were significantly higher in leaves extracts than stems extracts of Gaeddongssuk. But, ${\alpha}$-glucosidase inhibition activity was higher in stem than its leaves extract. In MTT assay by human breast adenocarcinoma cell line MCF-7 and MDA-MB-231, ethanol extracts of leaves showed the highest anticancer activity; the rates of growth inhibition were 76.26% and 52.59% on MCF-7 and MDA-MB-231 cells, at the concentration of $250\;{\mu}g$/mL, respectively. In conclusion, biological activities of extracts from Gaeddongssuk were dependent on the fiber, phenolic and flavonoid content.