• Korean Journal of Food Science and Technology
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• v.33 no.2
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• pp.178-183
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• 2001

This study was conducted to determine the optimal extraction condition of temperatures and kinds of extraction solvent, and antimicrobial activity of ethanol extract of Quercus mongolica leaf and organic acid against foodborne microorganisms. The antimicrobial activity of ethanol extract at $60^{\circ}C$ for 6 hour against foodborne microorganisms was stronger than those at $30^{\circ}C\;and\;90^{\circ}C$. Also, the ethanol extract showed stronger antimicrobial activity than those of water and methanol extract. The minimal inhibitory concentrations of the ethanol extract of Quercus mongolica leaf against B. cereus and L. monocytogenes, was $62.5{\sim}125\;{\mu}g/mL$ but, the minimal inhibitory concentration was $250\;{\mu}g/mL$ against S. typhimurium and P. aeruginosa and over $500\;{\mu}g/mL$ against E. coli O157:H7, respectively. The minimal inhibitory concentrations of the lactic, citric, acetic acid and the ethanol extract of Quercus mongolica leaf against B. cereus and L. monocytogenes was 2500, 5000, 1250 and $125\;{\mu}g/mL$, respectively. The combined effect of each organic acid and the ethanol extract against B. cereus was not observed but, synergistic effect was observed against L. monocytogenes. In the meantime, when the ethanol extract was combined with each organic acid at sub-lethal concentration, the combination did not increase the inhibitory effect of the most active single compound alone against E. coli O157:H7, respectively.

• Food Science and Preservation
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• v.18 no.6
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• pp.1002-1008
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• 2011

This study aimed to examine the effect of the Schizandra chinensis fruit and Morus alba leaf on insulin expression in HIT-T15 cells, which is exposed by glucose. The total polyphenol contents of the S. chinensis fruit ethanol extract and the M. alba leaf hot-water extract were $20.11{\pm}0.35$ mg/g and $50.02{\pm}0.62$ mg/mL, respectively. The S. chinensis fruit ethanol extract and the M. alba leaf hot-water extract contained $2.85{\pm}0.15$ and $8.76{\pm}0.43$ mg/g flavonoids, respectively. The antioxidant ability of the M. alba leaf hot-water extract was found to be superior to that of the S. chinensis fruit ethanol extract. Compared to the HIT-T15-treated 10 mM 2-deoxy-D-glucose, the $100{\mu}g/mL$ S. chinensis ethanol extract was found to have a two fold increase in insulin productivity. Moreover, the $100{\mu}g/mL$ M. alba leaf hot-water extract promoted the insulin secretion of high-glucose-damaged HIT-T15 almost ten fold. The above results showed that the S. chinensis fruit ethanol extract and M. alba leaf hot-water extract may improve the insulin productivity of the beta cell with glucose-induced oxidative damage. These data suggest that the S. chinensis fruit ethanol extract and the M. alba leaf hot-water extract can be used as food materials for the regulation of insulin secretion.

• Journal of Nutrition and Health
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• v.34 no.5
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• pp.499-512
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• 2001

This study was performed to investigate effects of dried leaf powders, water, 75% and 95% ethanol extracts of persimmon leaf and green tea on lipid metabolism, lipid peroxidation and antioxidative enzyme activity in 12-month-old rats. Fifty-four male Sprague-Dawley rats weighing 542$\pm$4.5g were blocked into groups according to their body weight and were raised for four weeks with the diets containing 5%(w/w) dried leaf powders of persimmon(Diospyros kaki Thunb) and green tea(Camellia Sinensis O. Ktze), water or 75% and 95% ethanol extracts from same amount of each dried tea powder. Food intake was not significantly different among all groups, but weight gain of green tea powder group was significantly lower than that of control group. Plasma and liver lipid levels of all the tea diet groups were lower than those of control group. Especially, 75% ethanol extract of persimmon leaf decreased total lipid and triglyceride concentrations in plasma and 95% ethanol extract of persimmon leaf decreased liver total lipid level. However, there was no difference between 75% ethanol extracts groups and 95% ethanol extracts groups in lipid metabolism. Superoxide dismutase(SOD) and catalase activities in erythrocyte were remarkably increased by all the green tea diets. SOD, catalase and glutathione peroxidase activities in liver were increased by the feeding of ethanol extracts from green tea and persimmon leaf powder. Liver xanthine oxidase activity was not different among all groups. Plasma Thiobarbirutic acid reactive substance(TBARS) concentrations of all the green tea diet groups were significantly low. It was thought that high flavonoids in green tea inhibited plasma lipid peroxidation by promoting SOD, catalase activities in erythrocyte. 95% ethanol extract of persimmon leaf also inhibited plasma lipid peroxidation by high vitamin E and beta-carotene. Persimmon leaf powder decreased liver TBARS concentration by vitamin E, betacarotene and vitamin C and by increasing activities of antioxidative enzymes with flavonoids. In conclusion, dried leaf powders, water, 75% and 95% ethanol extracts of persimmon leaf and green tea were effective in lowering lipid levels and inhibiting lipid peroxidation in 12-month-old rats. Above all, ethanol extracts of persimmon leaf decreased plasma and liver lipid levels and persimmon leaf powder effectively inhibited liver lipid peroxidation. Extracts of green tea leaf inhibited plasma lipid peroxidation. In lowering lipid levels and inhibiting lipid peroxidation, ethanol extracts were more effective than water extracts, but there was no difference between 75% ethanol extracts and 95% ethanol extracts in lipid metabolism. (Korean J Nutrition 34(5) : 499~512, 2001)

• Korean Journal of Pharmacognosy
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• v.41 no.4
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• pp.270-274
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• 2010

Obesity is caused from an imbalance between energy intake and expenditure, which may lead to pathologic growth of adipocytes and accumulation of fat in tissue. We examined the inhibitory effects of Eriobotrya japonica leaf and seed extracts on lipid absorption in vitro and fat accumulation during the differentiation of 3T3-L1 to adipocytes. 3T3-L1 preadipocytes were stimulated with DMEM media containing 10% FBS, 0.5 mM 3-isobuthyl-1-methyxanthine (IBMX), $5\;{\mu}g/ml$ insulin, and $1\;{\mu}g/ml$ dexamethasone for differentiation to adipocytes. E. japonica leaf extract at concentration of 0.5 or 1 mg/ml inhibited pancreatic lipase activity. The cell viability of 3T3-L1 adipocytes slightly reduced about 3% by treatment of E. Japonica leaf and seed extracts. The leaf and seed extracts of E. japonica effectively inhibited the accumulations of lipid droplet and expression of $C/EBP{\alpha}$ promoting adipogenesis. Thus, this data suggest that E. japonica leaf and seed extracts inhibit fat accumulation through regulation of $C/EBP{\alpha}$, and leaf extract is more effective in lipid absorption and adipogenesis than seed extract.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1891-1898
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• 2016

Imperata cylindrica, a tall tufted grass which has multiple pharmacological applications is one of the key ingredients in various traditional medicinal formula used in India. Previous reports have shown that I. cylindrica plant extract inhibited cell proliferation and induced apoptosis in various cancer cell lines. To our knowledge, no studies have been published on the effect of I. cylindrica leaf extract on human oral cancers. The present study was undertaken in order to evaluate the anticancer properties of the leaf extract of I. cylindrica using an oral squamous cell carcinoma cell line SCC-9 as an in vitro model system. A methanol extract from dried leaves of I. cylindrica (ICL) was prepared by standard procedures. Effects of the ICL extract on the morphology of SCC-9 cells was visualized by microscopy. Cytotoxicity was determined by MTT assay. Effects of the ICL extract on colony forming ability of SCC-9 cells was evaluated using clonogenic assay. Cell cycle analysis was performed by flow cytometry and induction of apoptosis was determined by DNA fragmentation assay. The ICL extract treatment caused cytotoxicity and induced cell death in vitro in SCC-9 cells in a dose-dependent manner. This treatment also significantly reduced the clonogenic potential and inhibited cell proliferation by arresting the cell cycle in the G2/M phase. Furthermore, DNA fragmentation assays showed that the observed cell death was caused by apoptosis. This is the first report showing the anticancer activity of the methanol extracts from the leaves of I. cylindrica in human oral cancer cell line. Our data indicates that ICL extract could be considered as one of the lead compounds for the formulation of anticancer therapeutic agents to treat/manage human oral cancers. The natural abundance of I. cylindrica and its wide geographic distribution could render it one of the primary resource materials for preparation of anticancer therapeutic agents.

• Journal of the Korean Wood Science and Technology
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• v.49 no.4
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• pp.384-393
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• 2021

Recently, due to environmental and toxicity issues, there has been increasing attention on research regarding natural products that can reduce the use of chemical fertilizers. Wood extracts derived from the biorefining process contain various fertilizer ingredients. HPLC analysis revealed that wood extract contains approximately 5.2% hemicellulosic sugar. The growth of lettuce (Lactuca sativa) upon treatment with wood extract (extract obtained from steam-exploded pine) or water-soluble fertilizers containing different nutrients was analyzed in this study. After two weeks, the growth characteristics of lettuce as affected by wood extract or water-soluble fertilizers were significantly different. The effect of water-soluble fertilizers containing ascorbic acid, magnesium sulfate, citric acid, potassium nitrate, amino acids, or seaweed extract was less desirable than that of wood extracts regarding plant height (18.6 cm), number of leaves (10), leaf length (14.1 cm), shoot fresh wight (9.8 g/plant), root fresh weight (0.8 g/plant) and shoot dry weight (0.6 g/plant). The plant height, number of leaves, leaf length, shoot fresh wight, root fresh weight, shoot dry weight of water-soluble fertilizers containing wood extract were significantly different compared to the control (plant height :13.5 cm, number of leaves : 7, leaf length : 9.4 cm, shoot fresh wight : 5.3 g/plant, root fresh weight : 0.7 g/plant, shoot dry weight : 0.4 g/plant, root dry weight : 0.07 g/plant). From these results, it was concluded that wood extract can be used as a potential water-soluble fertilizer to increase the yield of leafy vegetables.

• Journal of Applied Biological Chemistry
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• v.53 no.3
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• pp.170-173
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• 2010

Antioxidant and anticoagulant activities of water extract and 70% ethanol extract of Phyllostachys pubescence leaf (PPL) produced in Geoje were investigated. Total polyphenol contents of PPL-water extract and PPL-70%, EtOH extract were measured as $80.6{\pm}3.2$ and $71.3{\pm}2.7$ mg/g, respectively. DPPH radical scavenging activity of PPL-water extract and PPL-70% EtOH extract were 50% and 90%, respectively. The anticoagulant activity, in intrinsic pathway of activated partial thromboplastin time (APTT) showed a concentration-dependency. This results showed that PPL-water extract and PPL-70% EtOH extract have high antioxidant and anticoagulant activities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1315-1321
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• 2006

This study was conducted to investigate antioxidant activity and functional component analysis in different sections of Korean mountain ginseng (seed, leaf, stem and root). The major free amino acids were arginine, proline, $\gamma-amino-n-butyric$ acid, alanine and aspartic acid, and proline showed the highest content 22.98 mg/g in 80% MeOH extract of seed. Contents of $\gamma-amino-n-butyric$ acid and alanine were the highest in 80% MeOH extract of leaf, with 26.04 mg/g and 13.07 mg/g. Aspartic acid showed the highest content 23.42 mg/g in 80% MeOH extract of leaf. The major fatty acids were identified as palmitic acid, oleic acid and linoleic acid by GC. Content of total phenolic compounds were 737 mg% in 80% EtOH extract of seed, and 560 mg% in 80% MeOH extract of seed. The highest contents of ferulic acid and salicylic acid were $875{\mu}g/g\;and\;78{\mu}g/g$ in 80% MeOH extract of leaf, and $\rho-coumaric$ acid was $181{\mu}g/g$ in 80% MeOH extract of stem, respectively. The highest contents of ginsenoside-Rg1, Re, Rd and Rc were $14.5{\mu}g/g,\;48.78{\mu}g/g,\;27.57{\mu}g/g\;and\;4.87{\mu}g/g$ in 80% MeOH extract of leaf, respectively. Antioxidant activities by DPPH were 83.82% in water extract of leaf, 89.74% in 80% EtOH extract of leaf and 88.37% in 80% MeOH extract of leaf, and 92.81% in BHA (200 ppm). These results suggest that Korean mountain ginseng is very important as functional food material.

• Journal of the Korean Applied Science and Technology
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• v.34 no.2
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• pp.296-304
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• 2017

The purpose of this study was to investigate the applicability of the Psidium guajava leaf extract as a whitening functional cosmetic material. We measured DPPH radical scavenging activity, intracellular ROS, cytotoxicity in B16F10 melanoma cells and cytoprotective effect on ultraviolet A, in vitro tyrosinase inhibitory effect and melanin biosynthesis inhibitory effect. The antioxidative effect was confirmed through high DPPH radical scavenging activity and intracellular ROS activity inhibition measurement of the Psidium guajava leaf extract. The survival rate of B16F10 melanoma cells was more than 98% at all concentrations, and the cytoprotective effect from ultraviolet ray A was found to increase in a concentration-dependent manner. In addition, in vitro tyrosinase activity inhibitory effect of 10% and melanin biosynthesis inhibitory effect of 20% were observed. Through less toxicity for B16F10 melanoma cell, high antioxidant activity, inhibition of tyrosinase activity and melanin biosynthesis inhibitory effect, we confirmed the possibility of developing the Psidium guajava leaf extract as a whitening functional cosmetic material with a safe and excellent whitening effect.

• Journal of the Korean Applied Science and Technology
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• v.26 no.1
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• pp.87-92
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• 2009

In this study, we evaluated anti-oxidation and whitening effects of Ligularia stenocephala extract for use as the cosmeceuticals. L. stenocephala was extracted by three different solvents which was n-Hexane, ethyl acetate, $H_{2}O$. The free radical (1,l-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity of extract of L. stenocephala was in the order: ethyl acetate fraction of leaf ($IC_{50}$ value of 10.512ug/mL) > ethyl acetate fraction of stem ($IC_{50}$ value of 31.877ug/mL) > $H_{2}O$ fraction of leaf ($IC_{50}$ value of 129.194ug/mL). Reactive oxygen species (ROS) scavenging activity of extract of L. stenocephala was in the order: ethyl acetate fraction of leaf ($IC_{50}$ value of 0.230mg/mL) > ethyl acetate fraction of stem ($IC_{50}$ value of 0.528mg/mL) > $H_{2}O$ fraction of leaf ($IC_{50}$ value of 0.799mg/mL). Tyrosinase inhibition activity of L. stenocephala extracts was reduced 29.477% on ethyl acetate fraction of leaf, 13.583% on ethyl acetate fraction of stems. Therefore, L. stenocephala extracts may be useful as a new antioxidant and whitening agent to inhibit melanogenesis.