• The Korea Journal of Herbology
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• v.32 no.6
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• pp.1-7
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• 2017

Objectives : The heartwood of Sappan Lignum has been used since ancient times as an ingredient in folk medicines against anti-bacterial and anti-anemia purposes. Many bioactive constituents have been derived from this biomass such as chalcones and homoisoflavonoids. In the current investigation, the antioxidant and anti-diabetic properties using DPPH and $ABTS^+$ radicals scavenging, ${\alpha}-glucosidase$, and advanced glycation end products (AGEs) inhibition assays were evaluated by different extraction methods of Sappan Lignum. Methods : In our continuing investigation for bioactive natural ingredients, the antioxidant and ${\alpha}-glucosidase$ inhibitory properties of Sappan Lignum extracts were prepared from different extraction methods and the biological efficacies were investigated in vitro. The antioxidant properties were evaluated employing radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) ($ABTS^+$) radicals. In addition, the anti-diabetic effects of Sappan Lignum extracts were tested via ${\alpha}-glucosidase$ and AGEs formation inhibitory assay. The total phenolic contents were determined using a spectrophotometric method. Results : All the tested samples showed dose-dependent radical scavenging and ${\alpha}-glucosidase$ inhibitory activities. Among the tested extracts, the 80% methanolic extract of Sappan Lignum was showed the most potent activity with an $IC_{50}$ value of $82.3{\pm}1.7{\mu}g/m{\ell}$ against DPPH radical scavenging assay. While, $ABTS^+$ radical scavenging activity of 80% methanolic extract was higher than those of other extracts. Also, ${\alpha}-glucosidase$ inhibitory and AGEs formation effects of each extacts and total phenolic contents were evaluated. Conclusions : These results suggested that Sappan Lignum can be considered as a new effective source of natural antioxidant and anti-diabetic materials.

• Journal of Life Science
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• v.18 no.7
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• pp.963-967
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• 2008

The biological activities of water extracts from different fruit parts, such as peel, flesh, and placenta, of oriental melon were investigated. The concentrations of total phenolic in fruit extracts were $816.37\;{\mu}g/ml$, $385.23\;{\mu}g/ml$, and $925.56\;{\mu}g/ml$, respectively. Whereas the total flavonoid content in the peel extracts was $231.21\;{\mu}g/ml$, those in the extract of flesh and placenta were $8.16\;{\mu}g/ml$ and $36.07\;{\mu}g/ml$, respectively. The DPPH free radical scavenging activity of each fruit extract at 10,000 ppm was 34.84% for peel, 10.70% for placenta and 9.26% flesh. The ABTS radical cation decolorizing activity of each fruit extract at 10,000 ppm was in fruit extracts were 72.92% for peel, 48.0% for flesh and 74.31% for placenta. In addition, xanthine oxidase inhibitory activity, ${\alpha}-Glucosidase$ inhibition activity, and tyrosinase inhibition activity of the peel extracts appeared to be higher than those of placenta and flesh. Taken together, these results indicated that the peel part of oriental melon contained higher level of total flavonoid content, and several physiological activities including antioxidation, ${\alpha}-Glucosidase$ inhibition activity, and tyrosinase inhibition activity than did the flesh and placenta parts, and suggested that the peel might have a potential to be applicable as a source for functional foods.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.598-604
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• 2010

Electron donating ability (EDA), reducing power, total phenolic contents, total flavonoid contents, antimicrobial activity, and ${\alpha}$-glucosidase inhibitory effects of twenty-two sorghum varieties were examined using ethanol extracts (70%, v/v). The electron donationg abilities (EDA) of Mesusu and Bulgeunjangmoksusu (94% at 10 ${\mu}g$/mL) indicated higher antioxidant activity compared to those of other varieties and standard antioxidants such as BHT (13%) and BHA (74%). The reducing power of Mesusu ($OD_{700}$=0.71) suggested higher antioxidant activity, which was dependent on sample concentration. Bitjarususu showed the highest content of total phenolics (22.9 mg GAE/g); however, extracts from Heuinsusu exhibited the lowest content of total phenolics (16.4 mg GAE/g). Jangmoksusu showed the highest total flavonolic contents (3.5 mg QE/g), and Sigyeongsusu and Chal (GS) susu displayed the most antibacterial activity (MIC=8 ${\mu}g$/mL) against Escherichia coli. Extracts of Bulgeunjangmoksusu, Moktaksusu, and Ginjangmoksusu showed the highest ${\alpha}$-glucosidase inhibitory effect (98%) at the concentration of 5 ${\mu}g$/mL.

• Journal of Life Science
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• v.28 no.11
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• pp.1290-1300
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• 2018

The glucosinolate content, antioxidant activity, and antihypertensive and antidiabetic activities were measured in a crude extract of Dolsan leaf mustard kimchi (DLMK). The glucosinolate content was low at 6.41 and 7.92 mg/g in leaves and stems of DLMK after 21 days of fermentation. The total polyphenol and total flavonoid contents were more than 2 times higher in the leaves (211.7 mg GAE/g, 158.8 mg QE/g) than in the stem (53.7 mg GAE/g, 85.2 mg QE/g) during the fermentation period. The 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activity and electron donating ability (EDA) were similar to those of the control group after 14 days of fermentation, while the ferric reducing antioxidant power (FRAP) was higher in the leaves after 14 days of fermentation when compared to the control group. The angiotensin converting enzyme (ACE) inhibitory activity showed similar or higher inhibitory activity in the leaves when compared to the control group (0.01% captopril), and the ${\alpha}$-glucosidase inhibitory activity was higher in the leaves and stems when compared to the control group (0.05% acarbose). The glucosinolate content and the ABTS, ACE, and ${\alpha}$-glucosidase inhibitory activity were correlated, as determined by the observed straight line plot with a positive grade. During the fermentation period, the detected glucosinolates were sinigrin, glucobrasicin, glucotropeolin, and progoitrin. The DLMK extract is therefore expected to be valuable as a functional food because of its effective antioxidant, antihypertensive, and antidiabetic activities.

• Food Science and Preservation
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• v.23 no.7
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• pp.989-994
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• 2016

As part of our continuing search for bioactive natural products, the antioxidant and ${\alpha}$-glucosidase inhibitory activities of an 80% methanolic extract and organic solvent soluble-portions of Aruncus dioicus var. kamtschaticus roots were investigated by using a bioassay system. The antioxidant activity of A. dioicus var. kamtschaticus roots extract and organic solvent soluble-portions were assessed by examining with 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) ($ABTS^+$) radical scavenging. In addition, anti-diabetic effects of the A. dioicus var. kamtschaticus root extract and organic solvent soluble-portions were tested via ${\alpha}$-glucosidase inhibition assay. The total phenolic contents of the products were determined by applying UV-VIS spectrophotometry. All tested samples showed dose-dependent radical scavenging and ${\alpha}$-glucosidase inhibitory properties. In particular, the ${\alpha}$-glucosidase inhibitory and radical scavenging effects of the ethyl-acetate (EtOAc)-soluble portion from the roots of A. dioicus var. kamtschaticus were greater than those from other solvent-soluble portions. These results indicate that A. dioicus var. kamtschaticus could be considered a new effective source of natural antioxidants and anti-diabetic materials. More systematic research of the constituents of the roots of this A. dioicus variety will be conducted to further develop its antioxidative and anti-diabetic properties.

• Journal of Applied Biological Chemistry
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• v.61 no.4
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• pp.379-382
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• 2018

Trafficking process of viral glycoprotein to cell surface results in the syncytium formation when baby hamster kidney (BHK) cells was infected by Newcastle disease virus (NDV). Rhus chinensis gall, well-known as a medicinal plant, inhibited not only syncytium formation, but also trafficking of glycoprotein, hemagglutinin-neuramidase (HN) to the cell-surface. Modification of viral glycoprotein is processed within the endoplasmic reticulum and golgi body during trafficking into surface. R. chinensis gall extracts showed the strong inhibitory activities ($IC_{50}$ $12.5{\mu}g/mL$) against ${\alpha}-glucosidase$, when compared with the ${\beta}-glucosidase$. And this inhibitory activities is increased by the samples in a dose-depedent pattern. These data showed that the extracts of R. chinensis gall inhibited the cell-surface expression of NDV-hemagglutinin-neuramidase glycoprotein without significantly affecting HN glycoprotein synthesis in NDV-infected BHK cells.

• Korean Journal of Plant Resources
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• v.27 no.1
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• pp.22-28
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• 2014

In this study, we conducted the anti-HIV-1 enzymes assay in vitro and its active components were predicted by QSAR in silico for the elucidation of action mechanism on anti-HIV of natural resources. The extracts of Gardenia jasminoides var. radicans Makino were tested for their inhibitory effects on the reverse transcriptase (RT), protease and ${\alpha}$-glucosidase. In the enzyme inhibition assay, the methanol extracts of Gardenia jasminoides var. radicans Makino stem showed a strong activity of 32.5% on the enzyme activity to cleave an oligopeptide, resembling one of the cleavage sites in the viral polyprotein which can only be processed by HIV-1 protease. Moreover the methanol extracts of stem exhibited alpha-glucosidase inhibitory activities of 26.1%. The methanol extracts ($100{\mu}g/ml$) of stem showed a weak activity of 13.4% on anti-HIV-1 RT using Enzyme Linked Oligonucleotide Sorbent Assay (ELOSA) method. However, all extracts of leaf and stem didn't exhibit the HIV-1-induced cytopathic effects with IC (inhibitory concentration) of $100{\mu}g/ml$ in HIV-1-infected human T-cell line. From these results, it is suggested that Gardenia jasminoides var. radicans Makino extracts may possibly be involved in the inhibition of reverse transcriptase, protease and alpha-glucosidase but can't vitally concerned with the viral replication in vitro.

• Journal of Nutrition and Health
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• v.43 no.3
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• pp.215-223
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• 2010

Sasa borealis leaf has been known to have anti-diabetic properties. In this study, we tried to evaluate the effects of Sasa borealis leaf extract (SBE) on the inhibition of $\alpha$-glucosidase activity and postprandial glycemic response following ingestion of four carbohydrate-rich foods; cooked rice, ramen (instant noodle), noodle, and bread. Fourteen healthy female adults consumed 50 g of glucose (control) or one of the four foods containing 50 g of available carbohydrate with or without 2,000 mg of SBE. The activity of $\alpha$-glucosidase was inhibited dose-dependently by SBE. With SBE, blood glucose concentration at 15 min and the positive area under the curve (AUC) of postprandial glycemic response at 15 min and 30 min after consuming each of the four foods were reduced significantly. As the result, total positive AUC during 120 min was decreased in case of taking cooked rice or bread. Glycemic index and glycemic load of the four foods were declined from 13% to 23% with SBE. The results of this study suggest that SBE may be effective for postprandial glucose control by inhibiting $\alpha$-glucosidase activity.

• YAKHAK HOEJI
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• v.55 no.6
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• pp.446-450
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• 2011

As an effort to find a new scaffold for ${\alpha}$-glucosidase inhibition, we have prepared total 11 phenylalkylated piperazine derivatives and tested their ${\alpha}$-glucosidase inhibitory activities. Compounds 8 ($IC_{50}=2.73{\pm}0.075mM$) possessing two 3-methoxyphenethyl group on 1,4-position of piperazine showed comparable potency to acarbose used as reference. But other compounds were inactive to ${\alpha}$-glucosidase. The result indicated that proper substituents on the piperazine can engender ${\alpha}$-glucosidase inhibitory activities on the piperazine derivatives.

• 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.