• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.783-788
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• 2010

The purpose of this study is to investigate the antioxidative activity and digestive enzyme inhibition of grape seed extract (GSE). The GSE was tested for its effect on various antioxidative potentials (scavenging activities of DPPH radical, superoxide anion radical and hydroxyl radical) and inhibitory effect of various digestive enzymes (trypsin, $\alpha$-chymotrypsin, $\alpha$-amylase, $\beta$-glucosidase and lipase). DPPH radical scavenging activity ($SC_{50}$, 50% scavenging concentration) of GSE was 4.76${\pm}$0.27 ppm while those of positive controls (EGCG and vitamin C) were 2.22${\pm}$0.12 ppm and 9.50${\pm}$0.72 ppm, respectively. $SC_{50}$ value of GSE against superoxide anion radical and hydroxyl radical were 3.82${\pm}$0.07 ppm and 803.23${\pm}$27.16 ppm, respectively. In addition, $IC_{50}$ values of GSE against trypsin, $\alpha$-chymotrypsin, $\alpha$-amylase, $\alpha$-glucosidase and lipase were 2.17${\pm}$0.59 ppm, 7.46${\pm}$1.25 ppm, 18.25${\pm}$3.54 ppm, 12.30${\pm}$1.12 ppm, and 653.23${\pm}$79.34 ppm, respectively. These results suggest that GSE may be useful for the prevention or treatment of obesity.

• Food Science of Animal Resources
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• v.41 no.2
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• pp.274-287
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• 2021

The purpose of this study is to examine the physiological characteristics and anti-diabetic effects of Pediococcus pentosaceus KI62. The α-amylase and α-glucosidase inhibitory activity of P. pentosaceus KI62 was 94.86±3.30% and 98.59±0.52%, respectively. In MRS broth containing 3% maltodextrin inoculated by P. pentosaceus KI62, the amounts of short chain fatty acids (SCFA) were propionic acid 18.05±1.85 mg/kg, acetic acid 1.12±0.07 g/100 mL, and butyric acid 2.19±0.061 g/kg, and those of medium chain fatty acids (MCFA) were C8 0.262±0.031 mg/kg, C10 0.279±0.021 mg/kg, and C12 0.203±0.009 mg/kg. Compared to sixteen antibiotics, P. pentosaceus KI62 had the highest sensitivity to penicillin-G and rifampicin, as well as the highest resistance to vancomycin and ampicillin. The strain also showed higher leucine arylamidase and valine arylamidase activities than other enzyme activities, but it did not produce β-glucuronidase which is carcinogenic enzymes. The survival rate of P. pentosaceus KI62 in 0.3% bile was 91.67%. Moreover, the strain showed a 98.63% survival rate in pH 2.0. P. pentosaceus KI62 exhibits resistance to Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus at rates of 29.41%, 38.10%, 51.72%, and 50.47%, respectively. P. pentosaceus (23.31%) showed a similar adhesion ability to L. rhamnosus GG, the positive control (24.49%). These results show that P. pentosaceus KI62 has possibility as a probiotic with anti-diabetic effects.

• 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 East Asian Society of Dietary Life
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• v.18 no.4
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• pp.516-523
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• 2008

The effects of pan-fired (PM) and fermented (FM) Cudrania tricupidata tea leaves on $\alpha$-glucosidase inhibitory activity, oral glucose tolerance, blood glucose levels and serum lipids profiles in streptozotocin (STZ)-induced hyperglycemic rats were investigated. The $\alpha$-glucosidase inhibitory activity of FM ethanol extracts (20 mg/mL) was higher (92.5%) than that of raw dried leaves (RM) (69.1%) and PM (54.6%). In addition, the results of a glucose tolerance test revealed that the glucose levels of hyperglycemic rats that were fed PM and FM ethanol extracts and then orally administered glucose began to decrease after 60 minutes, but recovered after 120 minutes. However, the blood glucose levels in the hyperglycemic control group did not begin to decrease for 360 minutes. Additionally, the results of animal experiments that were conducted over five weeks to compare the dietary effects of PM and FM following hyperglycemic induction to the effects on the hyperglycemic control group (DM) were as follows: The body weight gain and FER of the treated rats were $12.9{\sim}16.9%$ higher than those of the DM group, whereas the amounts of feed and water intake by the treated rats were $6.8{\sim}10.1%$ lower. Additionally, the levels of blood glucose and serum fructosamine decreased by $27.3{\sim}39.8%$ and $6.7{\sim}20.0%$, respectively, in the treated rats. Moreover, the serum triglyceride, total cholesterol and LDL-cholesterol concentrations in the treated rats were $24.9{\sim}27.1%$, $15.9{\sim}17.4%$ and $33.8{\sim}38.4%$ lower, respectively. Finally, the HDL-cholesterol contents were $20.5{\sim}24.8%$ higher in the treated rats than in the control group. The above results suggest that PM and FM exerts an anti-hyperglycemic effect that occurs due to the inhibition of $\alpha$-glucosidase activity as well as via prevention and/or inhibition of changes in the serum lipid profile. In addition, the results of this study revealed that the synthetic anti-hyperglycemic effect of FM was greater than that of PM. However, further detailed studies are needed to confirm these results.

• The Korea Journal of Herbology
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• v.32 no.4
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• pp.47-52
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• 2017

Objective : Phellinus spp. mushroom is an object of interest because it has excellent anticancer effect. Owing to the similalarities in the morphology, Phellinus linteus and Phellinus baumii are often used as same Sang Hwang Mushroom in the Korean market.. The quality control for mushrooms is needed because there are many differences in the efficacy according to cultivation method and cultivation area. Therefore, a reliable authentication method of these herbal medicine is necessary to compare and measure the amount of beta-glucan which is known to have a hypoglycemic effect, from the mushrooms collected in various regions Methods : 7 samples of medicinal mushrooms supplying phellinus spp. were collected in Korea, China and Cambodia. We investigated the hardness, colors, extract ratio, ${\alpha}-amylase$ and ${\alpha}-glucosidase$ inhibitory activities, glucose transporter 4 (GLUT-4) expressions of water extracts from Phellinus spp and also MTT assay were examined for cell toxicity. Results : The results revealed that Phellinus spp.water Ext.inhibited ${\alpha}-glucosidase$ activity. glucose transporter 4 (GLUT-4), the key insulin signaling pathway transcription factor, was remarkably increased by the Phellinus baumii water extract Conclusions : These results suggest that The more yellowish the mushroom is, the lower the hardness, the more the content of ${\beta}-glucan$ is proportional. Because the more ${\beta}-glucan$, the greater the effect of hypoglycemia. compared to the hypoglycemic effect, Phellinus Baumii grown at hanging on selves for 7 month in the green house is the best.

• The Korean Journal of Food And Nutrition
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• v.29 no.6
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• pp.1040-1049
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• 2016

In this study, we aimed to develop a mixed tea prepared with roasted mulberry leaf and fruit using response surface methodology (RSM). Roasting of mulberry leaf was by 6 stages, as shown in Fig. 1; and mulberry fruit was roasted in 4 stages, as shown in Fig. 2. Subsequently, physicochemical measurements such as total polyphenol content, nitric oxide production content, and ${\alpha}$-glucosidase inhibitory effect were obtained for each sample. Central composite design was applied to prepare samples containing varying contents of roasted mulberry leaf (RoML) and roasted mulberry fruit (RoMF); subsequently, sensory evaluation was conducted. The total polyphenol content of roasted samples (RoML and RoMF) were significantly higher than that of raw samples (RaML and RaMF), respectively. The nitric oxide (NO) production of roasted samples were significantly lower than that of control (LPS induced RAW 264.7 cell). The ${\alpha}$-glucosidase inhibitory effect of roasted samples was significantly higher than that of raw samples, respectively. Based on the RSM estimation for determination of optimum ratio by sensory evaluation (taste, color, and flavor) among 13 mixed samples, the optimum mixing ratio of RoML and RoMF for taste, color, and flavor were 1.64 g (RoML) and 0.88 g (RoMF), 1.35 g (RoML) and 0.92 g (RoMF), 1.65 g (RoML) 1.03 g (RoMF), respectively. Based on results of three sensory evaluations, mixing ratio comprising 1.54 g of RoML and 0.92 g of RoMF is desirable for delicious tea with functionality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.1
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• pp.39-45
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• 2017

This study investigated the glycyrrhizic acid content and anti-diabetic activities of Glycyrrhiza uralensis (GU) depending on the cultivation region (Jecheon, Youngju, Gokseong, China, and Uzbekistan). Glycyrrhizic acid accuracy recovery and intra- and inter-day precisions (RSD%) of the method were calculated at 99.10~107.07% and 3.92 and 6.31% for GU samples, respectively, whereas the limits of detection and quantitation were 0.14 and $0.20{\mu}g/mL$. Anti-diabetic activity was measured by ${\alpha}-glucosidase$ and glucose uptake. GU (20 g) was extracted with 70% ethanol at $70^{\circ}C$ for 6 h. The Jecheon and Gokseong GU showed good inhibitory activity compared to the control. The Jecheon, Youngju, and Uzbekistan GU ethanol extracts ($100{\mu}g/mL$) showed glucose uptakes (in $C_2C_{12}$ myotube) of 124.19, 127.18, and 126.92%, respectively, compared to the positive control. In conclusion, these methods were validated for detection of glycyrrhizic acid in GU, and the results indicate that GU might have potential anti-diabetic activities.

• Journal of Applied Biological Chemistry
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• v.62 no.2
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• pp.173-179
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• 2019

The aim of this study is to investigate the biological activities of Hericium erinaceus. 1,1-Diphenyl-2-picrylhydrazyl radical scavenging activity of H. erinaceus extract was higher than positive control. The inhibitory activities of xanthin oxidase, ${\alpha}$-glucosidase, and hyaluronidase was measured as functional food activity, and inhibitory activities on collagenase, tyrosinase, and astringent effect as beauty food activity in water and ethanol extracts from H. erinaceus. In functional food activity, xanthin oxidase inhibitory activities at $50-200{\mu}g/mL$ phenolic concentration in ethanol extracts from H. erinaceus showed inhibitory activity in dose dependent manner. ${\alpha}$-Glucosidase inhibitory activities at $50{\mu}g/mL$ phenolic concentration showed high activity of higher than 80%. Inhibitory activities on hyaluronidase as anti-inflammation factor showed inhibition effect in dose dependent manner both in water and ethanol extracts. In beauty food activity, Inhibitory activities on collagenase at $200{\mu}g/mL$ phenolic concentration in water and ethanol extracts showed high activity to 65.09 and 58.38% dose dependently. Tyrosinase inhibitory activity in water extract showed 9.4-58.24%. Astringent activity as pore shrink effect in ethanol extracts also showed a very high activity of 18.94-100%. Antimicrobial activity on pathogenic bacteria was highly effective on Staphylococcus aureus, Salmonella enteritidis, Vibrio parahaemolyticus and Escherichia coli at 2.5 mg/mL or above. Therefore, the extracts from H. erinaceus can be used as a functional food and beauty food resources and natural antimicrobial agent on pathogenic bacteria in food.

• Journal of Plant Biotechnology
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• v.45 no.3
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• pp.279-286
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• 2018

Citrus grandis Osbeck pericarp is used as tea, herbal medicine, etc., but is not commercialized in various ways. So, in this study, we identified potential for use of Citrus grandis Osbeck as health functional foods, cosmetics and food preservatives. Methanol extract of Citrus grandis Osbeck pericarp was fractionated with hexane, dichloromethane, ethyl acetate and butanol, to quantitatively analyze total phenol and flavonoid, and investigate antioxidative and enzyme inhibitory activities. Total phenol and flavonoid contents were highest in ethyl acetate fraction, FRAP and ORAC results also revealed highest activity in proportion to total phenol content. DPPH radical scavenging activity revealed that ethyl acetate, butanol and dichloromethane fraction manifested highest activity without significant difference. However, dichloromethane fraction revealed higher TEAC value and tyrosinase inhibitory activity than ethyl acetate fraction, and hexane fraction manifested best results with superoxide radical scavenging activity and ${\alpha}-glucosidase$ inhibitory activity. Antimicrobial activity also revealed best effect in dichloromethane and hexane fractions. So, based on the following results, use of dichloromethane fraction as material of natural functional cosmetics, ethyl acetate fraction for health functional foods, and hexane fractions for pharmaceuticals and food preservatives, would be most practical for product development.

• 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.