• Korean Journal of Pharmacognosy
• /
• v.40 no.1
• /
• pp.1-5
• /
• 2009

The antioxidant and anti-diabetes effects were evaluated by the ethanol extracts from Astragalus membranaceus root classified by years using through DPPH radical scavenging activity, hydroxyl radical (${\cdot}OH$) scavenging activity, total phenolic and flavonoid contents, reducing power activity, $\alpha$-amylase and $\alpha$-glucosidase inhibitory activities. $IC_{50}$ values for DPPH radical scavenging activity of ethanol extract from 6 years old root ($749.25{\mu}g/mL$) was higher than 1 year ($1452.67{\mu}g/mL$) and 3 years old root ($1095.61{\mu}g/mL$). 6 years old root showed better effects in ${\cdot}OH$ scavenging activity ($IC_{50}$: $10.58{\mu}g/mL$), reducing power, total phenolic contents ($26.13{\pm}0.79\;Tan\;{\mu}g/mg$, $24.03{\pm}0.74\;Cat\;{\mu}g/mg$) $\alpha$-amylase ($33.33{\pm}0.55%$) and $\alpha$-glucosidase inhibitory activity ($49.71{\pm}1.01%$). On the other hand, total flavonoid compound contents were estimated much higher in 1 year old root ($44.93{\pm}1.35\;Que\;{\mu}g/mg$, $70.32{\pm}2.03\;Rut\;{\mu}g/mg$) than others. Based on these results, It was suggested that 6 years old root of A. membranaceus has a potential candidate for functional cosmetic and medicine.

• Food Science and Preservation
• /
• v.17 no.4
• /
• pp.541-546
• /
• 2010

Wild-garlic (Allium victorialis L.) is a perennial plant found in worldwide and has been considered as a favorite vegetable due to its particular smell and taste. However, the study of biological activity of wild-garlic and the development of processed food are in rudimentary. In this study, we evaluated several biological activities, including antioxidant, antimicrobial, and inhibitory activities against human thrombin, $\alpha$-amylase and $\alpha$-glucosidase, of Ulrung wild-garlic. Analysis of the composition showed that Ulrung wild-garlic is nutritive although it is perishable. The color of fresh juice was stably maintained during 10 days-storage at $4^{\circ}C$, but rapidly discolored by heat treatment at $70^{\circ}C$ for 1 h. During heat treatment, the contents of total sugar and total polyphenol were decreased to 75% and 50%, respectively, and acidity was increased from 0.069% to 0.111%. In a while, the brix, reducing sugar, and total flavonoids showed minor changes. The fresh juice showed strong DPPH scavenging activity, reducing power and antibacterial and antifungal activity, but the heat-treated juice lost the antioxidant and antimicrobial activities. The inhibitory activities against human thrombin and $\alpha$-amylase and $\alpha$-glucosidase was negligible in both fresh juice and heat-treated juice. These results suggested that the antioxidant and antimicrobial components in wild-garlic are heat-liable and volatile. Based on our results, we propose non-heat treatment products for processed wild-garlic, for example, fresh juice-added beverage or fermented liquors using wild-garlic.

• Korean Journal of Medicinal Crop Science
• /
• v.28 no.1
• /
• pp.21-28
• /
• 2020

Background: Owing to its high efficiency in lipid and protein production, peanut (Arachis hypogaea L.) is considered one of most important crops world-wide. The kernels of peanuts are undoubtedly the most important product this plant, whereas the skin is almost completely neglected in nutraceutical terms. However, peanut skin contains potentially health-promoting phenolics and dietary fiber, and there is considerable potential for commercial exploitation. In this study, we evaluated the α-glucosidase inhibitory activity of an extract of peanut skin (PS). Methods and Results: The α-glucosidase inhibitory effects of 80% ethanol extracts of peanut (A. hypogaea L. 'Sinpalkwang') skin were evaluated and found to have a half-maximal inhibitory concentration (IC₅₀) value of 1.2 ㎍/㎖. Progress curves for enzyme reactions were recorded spectrophotometrically, and the inhibition kinetics revealed time-dependent inhibition with enzyme isomerization. Furthermore, using ultra-high performance liquid chromatography combined with quadrupole-orbitrap mass spectrometry, we identified 26 compounds in the peanut skin extract, namely, catechin, epicatechin, and 24 proanthocyanidins. Conclusions: The results suggest that peanut skin can be utilized as an effective source of α-glucosidase inhibition in functional foods and nutraceuticals.

• The Korean Journal of Food And Nutrition
• /
• v.13 no.2
• /
• pp.134-138
• /
• 2000

An inhibitory activity against ${\alpha}$-glucosidase was identified in extracts of medicinal lichens, Parmelia austrosinensis and P. praesorediosa. The extracts retained almost all of their original activities when treated with heat, acid and alkaline conditions, and some hydrolytic enzymes. Partially purified inhibitor showed strong inhibition against disaccharide hydrolytic enzymes of mammalian and mold origin, but weak or no inhibition against polysaccharide hydrolytic enzymes except glucoamylase. The inhibitors from the two Parmelia sp. showed almost same retention time in HPLC. The inhibitor suppressed elevation of blood glucose level in rats after oral administration of soluble starch or sucrose.

• Nutritional Sciences
• /
• v.8 no.4
• /
• pp.226-230
• /
• 2005

To keep blood glucose levels as close to normal as possible is the major goal of diabetes mellitus treatment $\alpha$-Glucosidase is the enzyme that digests die1my carbohydrate and inhibition of this enzyme may suppress postprandial hyperglycemia. The methanol extract of Polygonum multiflorum Thunberg was tested for inhibitoty activity against $\alpha$-glucosidase in vitro and in vivo. Polygonum multiflorum Thunberg extract inhibited yeast $\alpha$-glucosidase activity in a concentration-dependent manner. Polygonum multiflorum Thunberg showed an $IC_{50}$ value of 0.48 mg/mL. The ability of Polygonum multiflorum Thunberg extract to lower postprandial glucose was studied in streptozotocin-induced diabetic rats. A starch solution (1 g/kg) with and without the methanol extract of Polygonum multiflorum Thunberg extract (500 mg/kg) was administered to diabetic rats by gastric intubation after an overnight fast A single oral dose of Polygonum multiflorum Thunberg 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 Polygonum multiflorum Thunberg may have an antihyperglycemic effect by inhibiting $\alpha$-glucosidase activity in the animal model of diabetes mellitus.

• Korean Journal of Medicinal Crop Science
• /
• v.25 no.3
• /
• pp.139-145
• /
• 2017

Background: Invasion of these invasive plants in the ecosystem threatens the habitat of endemic species, reduces biodiversity, and causes a disturbance in the ecological system. Hypochaeris radicata L. (Asteraceae), the most invasive plant in Korea, particularly in Jeju Island, invades farmlands, and autochthonous forests, resulting in the establishment of monocultures and modification of the ecosystem structure. Methods and Results: In this study was, we evaluated the biological activity of 70% ethanolic extracts from different parts of Hypochaeris radicata L. The biological activities of 70% ethanolic extracts of different parts, such as flower, leaf, stem, and root, of H. radicata were investigated. The total polyphenol content was highest in flower extracts ($50.82{\pm}3.16mg{\cdot}QE/g$). In addition, the highest flavonoid content was observed in flower extract ($15.19{\pm}2.03mg{\cdot}QE/g$). The flower extract of H. radicata exhibited stronger DPPH radical-scavenging activities, ABTS radical scavenging activities, and reducing power than the other parts. The flower extract of H. radicata was observed to have the highest tyrosinase and ${\alpha}-glucosidase$ inhibitory activities. Conclusions: The flower extracts of H. radicata exhibited remarkable antioxidant activity as well as tyrosinase and ${\alpha}-glucosidase$ inhibitory effects. These activities might be related to the phenolic compounds present in the H. radicata flower extract.

• Journal of Microbiology and Biotechnology
• /
• v.33 no.6
• /
• pp.797-805
• /
• 2023

Species belonging to the Vernonia (Asteraceae), the largest genus in the tribe Vernonieae (consisting of about 1,000 species), are widely used in food and medicine. These plants are rich sources of bioactive sesquiterpene lactones and steroid saponins, likely including many as yet undiscovered chemical components. A phytochemical investigation resulted in the separation of three new stigmastane-type steroidal saponins (1 - 3), designated as vernogratiosides A-C, from whole plants of V. gratiosa. Their structures were elucidated based on infrared spectroscopy (IR), one-dimensional (1D) and two-dimensional nuclear magnetic resonance (2D NMR), high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), and electronic circular dichroism analyses (ECD), as well as chemical reactivity. Molecular docking analysis of representative saponins with α-glucosidase inhibitory activity was performed. Additionally, the intended substances were tested for their ability to inhibit α-glucosidase activity in a laboratory setting. The results suggested that stigmastane-type steroidal saponins from V. gratiosa are promising candidate antidiabetic agents.

• The Korean Journal of Mycology
• /
• v.40 no.3
• /
• pp.164-173
• /
• 2012

For development of new high-value Korean traditional fermented food by using bioactive fungi and bacteria, Nuruk, Makgeolli and Cheonggukjang were prepared by mold, yeasts and bacteria from Korean traditional fermented foods and their physiological functionalities were investigated. Aspergillus oryzae N152-1 Nuruk showed the highest antihypertensive angiotensin I-converting enzyme inhibitory activity(57.2%), and Makgeolli made by Saccharomyces cerevisiae Y111-5 and commercial JS Ipguk (solid cultures of saccharifying enzyme-producing mold) was showed 42.0% of anti-obesity ${\alpha}$-glucosidase inhibitory activity. Among various Cheonggukjang, No 463 Cheonggukjang made by Brevibacterium iodinum NCDO 613(T) was showed the highest fibrinolytic activity (size of clear zone: 28 mm) and good anti-obesity ${\alpha}$-glucosidase inhibitory activity.

• Journal of Applied Biological Chemistry
• /
• v.65 no.2
• /
• pp.107-111
• /
• 2022

Biological activities such as antioxidant, anticoagulant, and α-glucosidase inhibitory effects of 40% (v/v) ethanolic extract from black locust (Robinia pseudoacacia L.) flower were investigated. The polyphenol content of the black locust flower extract was 39.8±0.5 mg gallic acid equivalents/g. The flower extract represented antioxidant effects such as free radical, cationic radical, and nitrite scavenging abilities as well as reducing power. Also the flower extract inhibited α-glucosidase activity and common pathway in plasma coagulation system.

• Food Science and Preservation
• /
• v.19 no.3
• /
• pp.400-405
• /
• 2012

To investigate the anti-diabetic activity of ethanol and aqueous peel and seed extracts obtained from three different grape species (Cambell Early, MBA, and Kyoho), alpha-glucosidase inhibitory activity was examined. All extracts showed anti-diabetic activity, especially aqueous extract exhibited inhibitory effect above 70%. Thus, we used aqueous extract to check the potential hypoglycemic effects in a streptozotocin (STZ)-induced diabetic mice model. The results showed that the blood glucose level of STZ-induced diabetic mice decreased drastically after 3 hr when the aqueous extract of Cambell Early seed was treated to the mice model. The aqueous extract of Kyoho seed lessened blood glucose level by 60%. Together, these data indicate that extracts of grape peel and seed (aqueous or ethanol) may have potential in improving hypoglycemic effects in the diabetic symptoms, suggesting that further investigation on biomarker expressions should be rewarding.