• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.11
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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 Pharmacognosy
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• v.40 no.3
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• pp.229-232
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• 2009

The ethanol (EtOH) extract of the branches of Cotinus coggygria (Anacardiaceae) exhibited a significant inhibition on the yeast $\alpha$-glucosidase, one of the key enzymes related with diabetes mellitus, in a dose dependent manner, in vitro. The intensive phytochemical survey of the EtOH extract of the species by way of bioactivity-guided fractionation resulted in the isolation of 1,2,3,4,6-penta-O-galloyl-$\beta$-D-glucose (1) as an active principle responsible for the inhibition on $\alpha$-glucosidase, together with two related components 2 and 3. Compound 1 demonstrated a strong inhibition on the yeast $\alpha$-glucosidase, in vitro and $IC_{50}$ value was calculated as 0.96 mg/ml, when that of a reference drug, acarbose was estimated as 5.3 mg/ml. On the other hand, other related constituents of the species, 1,2,3,6-tetra-O-galloyl-$\beta$-D-glucose (2) and gallic acid (3) were exhibited relatively poor inhibition upon the yeast $\alpha$-glucosidase, respectively.

• 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.

• Journal of Life Science
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• v.24 no.9
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• pp.935-945
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• 2014

Persimmon leaves were commonly consumed as beverages, but were also used as popular folk medicine in Asia. The purpose of this work was to assess the biological activities of Diospyros Lotus L. extracts (DLLE). Various solvent extracts, including n-Hexnae, $CHCl_3$, EtOAc, and n-BuOH fractions, were obtained from the methanol extract of Diospyros Lotus L. leaves. The increasing interest in the powerful biological activity of plant phenolics and flavonoids outlined the necessity for determining their content in medicinal herbs. In this study, the total polyphenol and flavonoid contents (TPC and TFC) in the EA fraction were higher than those of other fractions. The biological activities of DLLE were tested using the 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity assay, as well as superoxide dismutase (SOD) activity as an anti-oxidant effect and ${\alpha}$-glucosidase inhibitory activity as an anti-diabetic effect. The EA fraction with high TPC and TFC values showed the highest anti-oxidant effect and high ${\alpha}$-glucosidase inhibition. The EA fractions were further purified into eight fractions using open column chromatography. Higher anti-oxidant and anti-${\alpha}$-glucosidase activity were observed in polar fractions. The content of the flavonoids, including quercein-3-O-rutinoside, kaempferol-3-O-glucoside, myricetin, luteolin, and kaempferol, were analyzed in effective fractions using high-performance liquid chromatography (HPLC). The results suggest that DLLE have anti-oxidative and anti-diabetic effects and thus, have the potential as anti-diabetic materials and as a source for natural health products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.2
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• pp.149-155
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• 2012

In this study, the functional properties of royal court (RC) soy sauces, Gungjung-kanjang, were analyzed in vitro. RC soy sauces, traditional soy sauce, and commercial soy sauces were fractionated based on an MW cut-off of 1,000. The total phenolic compounds smaller than and larger than 1,000 MW (low and high fraction) in RC soy sauces were determined to be $101.55{\pm}1.49\sim114.00{\pm}0.11$ mg/L and $32.51{\pm}0.32\sim113.47{\pm}0.43$ mg/L, respectively. The low fraction of RC soy sauces showed around 51% superoxide dismutase (SOD)-like activity, which was higher than other soy sauces. Among RC soy sauces, Cheong-jang showed significantly high activity. Significant differences in fibrinolytic and antibacterial activities were not observed between soy sauces. ${\alpha}$-Glucosidase inhibitory activities in the low and high fractions of RC soy sauces were in the range from $6.34{\pm}1.51\sim8.79{\pm}0.81$% and $5.72{\pm}1.29\sim7.94{\pm}0.34$%, respectively. However, ${\alpha}$-glucosidase inhibitory activity in the high fraction of Kot-jang soy sauce was 75.88%${\pm}$1.20%. Lipase inhibitory activities in the low fractions of RC soy sauces, especially Cheong-jang, Deot-kangang, Jin-jang, and Euyeuk-kanjang, were also measured.

• The Korean Journal of Food And Nutrition
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• v.29 no.1
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• pp.128-133
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• 2016

This study aimed to evaluate the efficacy of the antioxidative and antidiabetic activities of the flowers, leaves, and roots of the Jerusalem artichoke (Helianthus tuberosus L.). The total polyphenol and flavonoid contents of the leaves were higher than those of the flowers and roots. However, the DPPH radical-scavenging and hydroxyl radical-scavenging activities of the flowers were higher than those of the leaves and roots. The nitrite-scavenging ability under acidic conditions was high in Jerusalem artichoke flower extracts. The ${\alpha}-glucosidase$ inhibitory activity and ${\alpha}-amylase$ inhibitory activity of a methanol extract of Jerusalem artichoke roots were about 60% (5 mg/mL concentration). Based on these experiments, it can be concluded that the flowers leaves, and roots of the Jerusalem artichoke can be used as natural preservatives. Therefore, they can be developed as functional foods, to take advantage of their antioxidant activity and abundant polyphenols. This study suggests that the whole Jerusalem artichoke, including roots, leaves, and flowers, is useful as a functional, nutritious food product.

• Korean Journal of Pharmacognosy
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• v.41 no.2
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• pp.130-135
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• 2010

This study was performed to the activity of antioxidant and anti-diabetic from Zanthoxylum schnifolium fruit. The Zanthoxylum schnifolium fruits were extracted with water, 100% methanol, 100% ethanol, 70% methanol and 70% ethanol. The activities of each extracts were measured by antioxidant tests, such as total phenolic contents, total flavonoid contents, hydroxyl radical activity, DPPH radical scavenging activity, reducing power and $\alpha$-glucosidase inhibition activity assay. The water extract represented the highest activity in the antioxidants properties in vitro, including hydroxyl radical activity, DPPH radical scavenging activity, reducing power. Furthermore, water extract also showed significantly high total phenolic contents but the 100% methanol extract showed high total flavonoid contents estimated as $196.48{\mu}g/mg$. The $IC_{50}$ values for $\alpha$-glucosidase inhibition activity of the 100% ethanol and 100% methanol extracts were $275.66{\mu}g/mg$ and $261.44{\mu}g/mg$. Our results indicated that the Zanthoxylum schnifolium fruit expected to be useful as antioxidants.

• Journal of Life Science
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• v.29 no.2
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• pp.164-172
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• 2019

In Korea, shiitake mushroom, Lentinula edodes, is cultivated on artificial medium containing oak sawdust and wheat bran. The annual production of spent mushroom substrate (SMS) of shiitake, a byproduct of the mushroom industry, is estimated to reach over 50,000 tons per year. This study aimed to improve the use of SMS as a novel bioresource. Hot water extracts of SMS after the first and third harvest were prepared and their bioactivities evaluated. Hot water extracts of uninoculated medium and shiitake were used as controls. Extracts of SMS showed higher radical scavenging of DPPH anions, ABTS cations, nitrites, and a higher reducing power than those of shiitake or medium extracts. After the first and third harvests at 0.5 mg/disc, SMS extracts showed no antibacterial or antifungal activities against the pathogenic and food-spoilage bacteria and fungi. However, they showed good inhibitory activities against ${\alpha}$-glucosidase at 0.5 mg/ml. In addition, SMS extracts had strong anti-coagulation activities via their inhibition of thrombin, prothrombin, and blood coagulation factors without platelet aggregation activity. Our results suggested SMS should no longer be perceived as a useless byproduct but should be understood as a novel bioresource, the extracts of which could be developed as antioxidant, antidiabetic, and antithrombosis agents.

• Food Science and Preservation
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• v.24 no.5
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• pp.615-622
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• 2017

This study investigated the antioxidant and antidiabetic activities of Stachys sieboldii Miq. extracts by solvents (water, ethanol, butanol, chloroform, and hexane). The contents of total polyphenols (7.18-37.25 mg/g) and flavonoids (0.21-5.21 mg/g) in extracts from Stachys sieboldii Miq. showed a significant difference dependent on the extraction solvents, butanol > ethanol > water > chloroform > hexane. Antioxidant activities by DPPH and ABTS radical scavenging were increased in a dose-dependent manner. These activity trends associated with the extraction solvent were different at each concentration, but resembled phenolic compound contents trend, generally. FRAP value increased in a dose-dependent manner, but there was a difference in radical scavenging activities when comparing between extraction solvents by butanol > ethanol > hexane > chloroform > water on all concentrations. The trend of ${\alpha}$-amylase inhibition of extracts from $1,000{\mu}g/mL$ to $2,000{\mu}g/mL$ was not affected as enzyme activity is promoted and not inhibited. The inhibition of ${\alpha}$-glucosidase was increased in a dose-dependent manner without water extracts, the activity on hexane extracts was higher than others per the extraction solvent. ${\alpha}$-Glucosidase inhibition of hexane extracts showed 57.76% at $250{\mu}g/mL$, which is 2.8 times higher than the second highest chloroform extract (20.65%). From these results, we presume that the active ingredients of Stachys sieboldii Miq. is different according to the extraction solvent and also the activity is different by these major functional groups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.7
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• pp.975-979
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• 2010

Biological activities of different parts (stems, leaves, roots, fruits) and solvents (water, ethanol) of seabuckthorn (Hippophae rhamnoides L.) grown in Korea were tested as follows. In the experiment of inhibiting $\alpha$-glucosidase activity, ethanol extract of Hippophae rhamnoides L. stem showed the highest inhibitory activity by 93% and the next highest was the ethanol extract of its leaf by 88.7%. In the case of these two extracts, the effect of inhibiting $\alpha$-glucosidase activity was extraordinarily great when comparing with control group, acarbose. In the experiment of inhibiting $\alpha$-amylase activity, water extract of leaf showed the highest result by 54.7%, among all extracts. Regarding anticancer effect for HT-29 cell and DU-145 cell, water extract of root showed 47.1% and 32.3% activities, respectively. The experiment on antibacterial activity showed that the ethanol extract from the leaf inhibitory activity of Clostridium butyricum, Proteus mirabilis, and Shigella flexneri which are the several food borne pathogenic strains. In future research, materials for biological activity appear isolated and purified and research should continue.