• 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.

• Food Science and Preservation
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• v.30 no.2
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• pp.358-368
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• 2023

Euonymus alatus (Thunb.) Sieb., also known as the arrow tree in Korea, is a plant in East Asia used in traditional medicine and food. In particular, the wings of E. alatus are rich in phenolic compounds. This study evaluated the antioxidant, α-glucosidase inhibition, and anti-cancer activities of E. alatus wing extracts. The radical and hydrogen peroxide scavenging acitvities and reducing the power of 1,000 ㎍/mL E. alatus wing extracts, were similar to those of the positive control (0.1% BHT, 0.1% α-tocopherol). In addition, ethanol and methanol extract at 250 ㎍/mL showed 95.70 and 94.99% of α-glucosidase inhibition activity, respectively. The ethanol extract of E. alatus wings had the highest total polyphenol and flavonoid contents (867.8 mg% and 521.7 mg%, respectively). The E. alatus wing extracts significantly decreased the cell viability of LNCaP human prostate cancer cells (p<0.001), MDA-MB-231 human breast cancer cells (p<0.001), and HT-29 human colon cancer cells (p<0.001) in a dose-dependent manner. However, there was no significant effect on B16 mouse melanoma cells. Notably, the ethanol extracts showed higher cancer cell growth inhibitory activity in LNCaP and HT-29 cells than the other extracts. These results suggest that E. alatus wing extracts could have significant clinical applications, and our results can be used as basic data for future functional food material development.

• Journal of Nutrition and Health
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• v.47 no.1
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• pp.12-22
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• 2014

Purpose: This study was conducted to establish the production conditions through optimization of the production process of beverages using Aspergillus oryzae CF1001, and to analyze volatile compounds and antidiabetic activity. Methods: The optimum condition was selected using the response surface methodology (RSM), through a regression analysis with the following independent variables gelatinization temperature (GT, $X_1$), saccharogenic time (ST, $X_2$), and dependent variable; ${\Delta}E$ value (y). The condition with the lowest ${\Delta}E$ value occurred with combined 45 min ST and $50^{\circ}C$ GT. The volatile compounds were analyzed quantitatively by GC-MS. Results: Assessment of antidiabetic activity of saccharogenic mixed grain beverage (SMGB) was determined by measurement of ${\alpha}$-glucosidase inhibition activity, and glucose uptake activity and glucose metabolic protein expression by reverse transcriptase polymerase chain reaction (RT-PCR) and western blot analysis. Results of volatile compounds analysis, 62 kinds of volatile compounds were detected in SMGB. Palmitic acid (9.534% ratio), benzaldehyde (8.948% ratio), benzyl ethyl ether (8.792% ratio), ethyl alcohol (8.35% ratio), and 2-amyl furan (4.826% ratio) were abundant in SMGB. We confirmed that ${\alpha}$-glucosidase inhibition activity, glucose uptake activity, and glucose-metabolic proteins were upregulated by SMGB treatment with concentration dependent manner. Conclusion: Saccharogenic mixed grain beverage (SMGB) showed potential antidiabetic activity. Further studies will be needed in order to improve the taste and functionality of SMGB.

• Journal of Plant Biotechnology
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• v.50
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• pp.200-206
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• 2023

Although softwoods are widely distributed in Korea and used in various industries, studies are limited and comparative research on softwoods has been overlooked. Therefore, in this study, the physiological activity of four species of softwoods found in Korea was quantified. Needles and cones of Pinus densiflora, Chamaecyparis obtusa, Cryptomeria japonica, and Abies koreana were collected, and material was extracted using 70% methanol. We quantified the following physiological traits: total phenol and flavonoid content, antioxidant activity (DPPH, TEAC, FRAP), and inhibitory activity of the enzymes α-glucosidase, elastase, and tyrosinase. Total phenol and flavonoid contents and antioxidant activities were high in Chamaecyparis obtusa and Cryptomeria japonica, and α-glucosidase inhibition activity was highest in the leaves of Chamaecyparis obtusa. Elastase inhibitory activity was high in the leaves and cones of Pinus densiflora and the cones of Abies koreana, and tyrosinase inhibitory activity was highest in the leaves of Pinus densiflora. In Korea, softwoods are planted extensively on roadsides and as windbreaks, and they are highly competitive in supplying raw materials since they are pruned every year. Based on the results of this study, softwoods are considered suitable for use in healthcare products, diabetes products, wrinkles, and whitening cosmetics.

• Journal of Life Science
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• v.30 no.2
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• pp.169-177
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• 2020

For this study, we prepared organic solvent fractions from methanol extracts of Houttuynia cordata and Lespedeza cuneate, and analyzed their chemical components and various biological functions such as anti-oxidation, angiotensin-converting enzyme (ACE) inhibition, and α-glucosidase inhibitory activities. We found that DPPH radical scavenging activity was highest in the ethyl acetate fractions of Houttuynia cordata (90.8%) and Lespedeza cuneata (91.2%), whereas ABTS radical scavenging activity was highest in the ethyl acetate fractions of Houttuynia cordata (86.1%) and the chloroform fractions of Lespedeza cuneata (95.6%). FRAP activity was highest in the ethyl acetate fraction of Houttuynia cordata (360.1 mg TE/g) and Lespedeza cuneata (239.2 mg TE/g). ACE inhibitory activity was highest in the chloroform fraction of Houttuynia cordata (13.2%) and Lespedeza cuneata (35.2%). And, α-glucosidase inhibitory activity was highest in the ethyl acetate fraction of Houttuynia cordata (56.3%), and the water residue of Lespedeza cuneata (93.6%). Finally, we investigated the DPPH radical scavenging activity of 20 types of pure compounds identified in Houttuynia cordata and Lespedeza cuneate. The results show that quercetin demonstrates the highest DPPH radical scavenging activity. Overall, these results help us to understand the functional chemical components of Houttuynia cordata and Lespedeza cuneate and the biological effects of these components.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.276-281
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• 2008

Extracts from Rododendron mucronulatum Turcz. flowers were tested for antioxidant and their inhibitory activities of ${\alpha}$-amylase, ${\alpha}$-glucosidase and angiotensin converting enzyme (ACE). Total contents of phenolics were found as $30.6{\pm}0.14mg/g$ (60% EtOH extract) and $23.2{\pm}0.21mg/g$ (water extract). Electron donation ability (EDA), ABTS [2,2azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] radical decolorization, Antioxidant protection factor (PF) and thiobarbituric acid reactive substance (TBARs) were measured for the antioxidative activity of the extracts from Rododendron mucronulatum Turcz. flowers. The water extract were determined as 97.5% at ethanol extract showed 83.2% and 60% EtOH extract were 89.7% in EDA. The water extract showed higher antioxidant activity than 60% EtOH extract when evaluated by ABTS radical decolorization and antioxidant PF. The TBARS of water extracts and 60% EtOH extracts were shown as $0.29{\times}10^2{\mu}M\;and\;0.28{\times}10^2{\mu}M$, respectively, and were lower than control. ACE inhibitory activity in water extract (67.6% inhibition) was higher than that of 60% EtOH extract (46.7% inhibition) at $200{\mu}g/mL$. Water extracts had higher inhibitory activities on ${\alpha}$-amylase and ${\alpha}$-glucosidase than 60% EtOH extracts. The result suggests that the water extract from Rododendron mucronulatum Turcz. flowers will be useful as natural antioxidants and functional foods.

• Journal of Nutrition and Health
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• v.49 no.1
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• pp.18-27
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• 2016

Purpose: Our previous study demonstrated the hypoglycemic effects of mulberry (Morus alba L.) leaf and the underlying mechanisms. Here we explored the potency of mulberry twigs (TW) and root barks (RB) in postprandial hypoglycemic effects in vitro and in vivo. Methods: The major components of TW and RB were determined by high performance liquid chromatography (HPLC). Alpha-glucosidase inhibition and glucose/fructose uptake inhibition in Caco-2 cells were determined for TW, RB, and their major components, followed by an oral sugar tolerance test (OSTT) in streptozotocin-induced diabetic rats. Male Wistar rats were fed a high-fat diet for 2 weeks and then a single dose of streptozotocin (35 mg/kg B.W) was administered by intraperitoneal injection. Rats with fasting blood glucose levels above 126 mg/dL were randomly divided into 5 groups (n = 8/group) for the following treatments by gavage for 4 weeks: vehicle (normal control and diabetic control), 200 mg/kg B.W of TW or RB or 100 mg/kg B.W of oxyresveratrol (OXY). Results: OXY and mulberroside A were identified as the major components of TW and OXY, mongolicin, and kuwanon H for RB. A significant inhibitory activity on ${\alpha}-glucosidase$ was found for TW, RB, and OXY (p = 0.0099). There was a dose-dependent inhibition of TW and RB on the intestinal sugar uptakes in Caco-2 cells, showing a greater impact on fructose compared to glucose. The OSTT showed that TW and RB significantly delayed time to maximal concentration (p = 0.0088) and decreased maximal concentration (p = 0.0043) compared to the control group. Conclusion: These results suggest that TW and RB may have a postprandial hypoglycemic effect, particularly in the case of high fructose or sucrose intake. OXY was suggested as a contributor to the hypoglycemic effect of TW and RB. Further studies are needed for the systemic effect of TW and RB in circulation.

• Korean Journal of Medicinal Crop Science
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• v.19 no.5
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• pp.325-333
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• 2011

This study was carried out to evaluate biological activities to different ethanol extracts from unripened and ripened fruit (Rubus coreanus Miq.). 25% to 75% ethanol extracts of unripened and ripened fruits were similar to extract yield respectively. Yield of ethanol extract of ripened fruit were approximately 3 times higher than that of unripened fruit. 75% ethanol extract of unripened fruit showed the highest contents of total polyphenol ($180.04{\pm}0.41$ mg/g) and total flavonoid ($50.43{\pm}0.81$ mg/g). Contents of total polyphenol and total flavonoid of unripened fruit were about 2 times higher than those of ripened fruit. $IC_{50}$ values of DPPH radical scavenging activity and linoleic acid peroxidation inhibition activity of BHA and ${\alpha}$-tocopherol showed $13.19{\pm}0.21$ and $18.16{\pm}0.23{\mu}g/m{\ell}$, $4.25{\pm}0.04{\mu}g/m{\ell}$ and $5.56{\pm}0.10{\mu}g/m{\ell}$ respectively, but 75% ethanol extract of unripened fruit showed the lowest $23.85{\pm}0.10{\mu}g/m{\ell}$ and $7.34{\pm}0.07{\mu}g/m{\ell}$ among other all extracts. $IC_{50}$ values of LDL (low density lipoprotein) oxidation inhibition activity and ${\alpha}$-glucosidase inhibitory activity of 75% ethanol extract of unripened fruit showed the lowest $1.04{\pm}0.04{\mu}g/m{\ell}$ and $7.21{\pm}0.13{\mu}g/m{\ell}$ among other all extracts respectively. Specifically, 75% ethanol extract of unripened fruit has relatively better biological activities than other ethanol extracts, it could be potentially used as bioactive source for health functional foods.

• The Korean Journal of Food And Nutrition
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• v.22 no.1
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• pp.41-47
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• 2009

This study investigated antioxidative and hypoglycemic activities of Omija for evaluation of usefulness as a functional food resource. Omija water extracts were extracted with water for 24 hr, 6 hr and 3 hr at room temperature, 60$^{\circ}C$ and 100$^{\circ}C$, respectively. Omija ethanol extracts were extracted with 60% ethanol for 24 hr and 3 hr at room temp temperature and 60$^{\circ}C$, respectively. The antioxidant properties of Omija(Schizandra chinensis Baillon) extracts prepared under different extraction conditions were evaluated by a variety of radical scavenging assays including DPPH, $ABTS^{{cdot}+}$, and nitrite and reducing power. Hypoglycemic activity was examined for $\alpha$-glucosidase inhibition using an in vitro model. The total phenolic content was also determined. Antioxidant activities of Omija were the highest in the group extracted with 60% ethanol for 3 hr. The ethanol extracts showed higher activity than water extracts. An extraction temperature was the highest in 60$^{\circ}C$. The total phenolic content extracted with 60% ethanol for 3 hr at 60$^{\circ}C$ was 530 mg GAE/100 g. The water extract extracted with water for 24 hr at room temperature showed the lowest antioxidant activity and phenolic content. $\alpha$-glucosidase inhibitory activity was the highest in the group extracted with 60% ethanol for 3 hr at 60$^{\circ}C$, followed by the group extracted with 60% ethanol for 24 hr. The results suggest that extraction of Omija by 60% ethanol for 3 hr at 60$^{\circ}C$ will be useful as a functional food resource with natural antioxidants and hypoglycemic activities.

• Food Science and Preservation
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• v.30 no.1
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• pp.170-178
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• 2023

We investigated the free radical scavenging and digestive enzyme inhibitory activities of the hot water extract of peach twig (Prunus persica L. Bastch). This extract of the peach twigs was further split up into n-hexane, ethyl acetate (EtOAc), and n-butyl alcohol(n-BuOH), which resulted in three solvent-soluble fractions. Free radical scavenging activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺) assay systems, while hypoglycemic effect of the peach twig extract and the solvent-soluble fractions were tested using α-glucosidase and α-amylase inhibition assays. Accordingly, the EtOAc layer showed a greater free radical scavenging activity compared to other solvent-soluble fractions. Furthermore, based on the α-glucosidase and α-amylase assays, the IC₅₀ values were determined to be 38.2±1.6 and 69.6±6.1 ㎍/mL for the EtOAc-soluble fractions, respectively. Taken together, these results suggest that the fractions obtained from the peach twig extract can be considered as a potential source of natural antioxidant and hypoglycaemic constituents.