• Korean Journal of Medicinal Crop Science
• /
• v.14 no.4
• /
• pp.206-211
• /
• 2006

This study was performed to examine antitumor activities of Rubus coreanus Miquel and Angelica gigas Nakai extracts against sarcoma-180 and anti-stress activities in ICR mice. The variation of body weights of the 20 days of Rubus coreanus extracts-administrated mice group was very low. The survival rate (T/C %) of Rubus coreanus extract administrated group was 161% after 50 days from the inoculation of sarcoma-180 and the increment of their body weights was suppressed. Anti-stress effect of the extracts of R. coreanus and A. gigas were estimated by maeasuring blood chemical value and internal organs weight in ICR mice. The extracts of R. coreanus reduced the cholesterol and glucose to the normal level in the all stress animal models. The extracts of R. coreanus reduced the hypertrophy of the internal organs such as adrenal, spleen and liver to the regular level.

• Korean Journal of Food Science and Technology
• /
• v.42 no.4
• /
• pp.424-430
• /
• 2010

Immuno-modulatory activities of peptides from Asterias amurensis were investigated using a nano-encapsulation process. The molecular weights of the peptides in the range of 5-7 kDa were separated using Sephadex G-75 gel filtration. Eighty-five percent of the nano-particles were in the 300 nm range using dynamic light scattering. The cytotoxicity of the A. amurensis nano-particles against CCD-986sk human dermal fibroblast cells was 11.64% after adding 1.0 mg/mL of the samples, which was lower than that from the control (13.28% collagen). The secretion of $NO^-$ from macrophages was estimated as $40\;{\mu}M$ after adding 1.0 mg/mL of gelatin nano-particles, which was higher than the others. Prostaglandin $E_2$ production from UV-induced human skin cells decreased greatly to 860 pg/mL after adding 1.0 mg/mL of the samples. Confocal microscopy revealed that nano-particles effectively penetrated the cells within 1 hour. From these results, we consider that nano-encapsulation of the peptides from A. amurensis can improve their biological functions.

• Journal of Life Science
• /
• v.29 no.12
• /
• pp.1305-1313
• /
• 2019

Licochalcone (LC), isolated from the roots of Glycyrrhiza inflata has multiple pharmacological effects including anti-inflammatory and anti-tumor activities. To date, Licochalcone C (LCC) has induced apoptosis and inhibited cell proliferation in oral and bladder cancer cells, but lung cancer has not yet been studied. In addition, no study reported LCC-induced autophagy in cancer until now. The present study was designed to investigate the effect of LCC on gefitinib-sensitive and -resistant lung cancer cells and elucidate the mechanism of its action. The 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay data showed that LCC significantly inhibited cell viability in non-small cell lung cancer (NSCLC) HCC827 (gefitinib-sensitive) and HCC827GR (gefitinib-resistant) cell lines. Interestingly, Annexin V/7-aminoactinomycin D double staining and cell cycle analysis showed an apoptosis rate within about 20% at the highest concentration of LCC. LCC induced G2/M arrest by reducing the expression of the cell cycle G2/M related proteins cyclin B1 and cdc2 in NSCLC cell lines. Treatment of LCC also induced autophagy by increasing the expression of the autophagy marker protein microtubule-associated protein 1 light chain 3 (LC3) and the protein autophagy-related gene 5 involved in the autophagy process. In addition, LCC increased the production of reactive oxygen species (ROS), and the cell viability was partially restored by treatment with the ROS inhibitor N-acetyl-L-cysteine. In western blotting analysis, the expression of cdc2 was increased and LC3 was decreased by the simultaneous treatment of NAC and LCC. These results indicate that LCC may contribute to anti-tumor effects by inducing ROS-dependent G2/M arrest and autophagy in NSCLC. In conclusion, LCC treatment may be useful as a potential therapeutic agent against NSCLC.

• Applied Chemistry for Engineering
• /
• v.23 no.1
• /
• pp.93-99
• /
• 2012

In this study, the evaluation of antioxidative activity and componential analysis of C. obtusa leaf extracts was carried out. Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of C. obtusa leaf extracts on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system were investigated using the luminol-dependent chemiluminescence assay. The ethyl acetate fraction ($OSC_{50}$; 0.22 ${\mu}g/mL$) and aglycone fraction of C. obtusa leaf extracts (0.20 ${\mu}g/mL$) showed about 7 times more prominent ROS scavenging activity than L-ascorbic acid (1.50 ${\mu}g/mL$). The cellular protective effects of fractions obtained from C. obtusa leaf extracts on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The ethyl acetate fraction and aglycone fraction of C. obtusa leaf extracts showed the cellular protective effects in a concentration dependent manner (5~25 ${\mu}g/mL$). The inhibitory effect ($IC_{50}$) of ethyl acetate fraction and aglycone fraction on tyrosinase exhibited 74.43 and 53.80 ${\mu}g/mL$, repectively. The aglycone fraction showed four times higher tyrosinase inhibitory effect than arbutin (226.88 ${\mu}g/mL$), known as a whitening agent. The aglycone fraction of C. obtusa leaf extracts showed three bands in TLC chromatogram and three peaks in HPLC chromatogram (360 nm). Three compounds were identified as taxifolin, quercetin and kaempferol. These results indicate that the fractions of C. obtusa leaf extracts can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against reactive oxygen species. The fractions of C. obtusa leaf extracts can be applicable to new functional cosmetics for antioxidan and whitening effects.

• Microbiology and Biotechnology Letters
• /
• v.38 no.3
• /
• pp.283-288
• /
• 2010

Yam (Dioscorea spp.) has been used as important edible and medicinal natural resource in worldwide and D. alata L. is most popular nourishment among the yam. In this study the composition, color, antioxidation and antimicrobial activity of D. alata Gyeongbuk No. 6 (GB-6), which was established in Gyeongbuk Agricultural Research & Extension Services, Andong, Korea, was compared to those of D. batatas Gyeongbuk No. 1 (GB-1), a major domestic cultivation species. Water content of GB-6 was $78.02{\pm}0.16%$, which is slightly lower than that of GB-1 ($82.6{\pm}0.07%$). The contents of crude protein, crude fat, crude fiber and ash of GB-6 were 0.95, 0.26, 0.85 and 0.70%, whereas those of GB-1 were 1.58, 0.15, 1.39 and 0.88%, respectively. Analysis of color using colormeter showed that the GB-6 is slight dark-yellow than GB-1, and total polyphenol content of GB-6 was 2-fold higher compared than that of GB-1. Sequential organic solvent fractions from methanol extract of GB-6 showed that the ethylacetate fraction has highest total polyphenol ($144.1{\pm}3.20\;mg/g$). Determination of antioxidation activity showed that the ethylacete fraction and water fraction has strong DPPH radical scavenging activity ($IC_{50}=78.32\;{\mu}g/mL$) and reducing power, respectively. In antimicrobial activity assay, the n-hexane and ethylacetate fraction showed antibacterial activity against B. subtilis, L.monocytogenes, S. epidermidis, S. aureus, P. vulgaris, and S. typhimurium. These results provide the possibility of domestic cultivated D. alata GB-6 as a healthy food.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.7
• /
• pp.975-982
• /
• 2015

Piceatannol (trans-3,4,3',5'-trihydroxystilbene), a natural stilbene, is an analogue of resveratrol. In the present study, possible mechanisms by which piceatannol exerts its pro-apoptotic action in cultured human oral cancer YD-15 cells were investigated. To investigate whether or not piceatannol has effects on cancer cell viability, human oral YD-15 cells were treated with piceatannol (0, 50, and $100{\mu}M$). Piceatannol treatment ($100{\mu}M$) showed the strongest inhibition of cell proliferation and reduced cell viability in a dose-dependent manner. Chromatin condensation detected by DAPI staining significantly increased in a concentration-dependent manner, indicating apoptosis. Piceatannol treatment activated initiator Bax (pro-apoptotic) and cPARP in a concentration-dependent manner. Further, piceatannol induced down-regulation of Bcl-2 (anti-apoptotic). We also evaluated the activity of piceatannol against oral cavity cancer tumors in mice. Piceatannol-treated nude mice bearing YD-15 xenograft tumors exhibited significantly reduced tumor volume and weight due to the potent effect of piceatannol on tumor cell apoptosis, as determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. Immunohistochemistry staining showed elevated expression of cleaved-caspase-3 as well as reduced expression of Ki-67 in the piceatannol-treated group. Therefore, piceatannol can be developed as a cancer preventive medicine due to its growth inhibitory effects and induction of apoptosis in human oral cancer cells.

• Tuberculosis and Respiratory Diseases
• /
• v.47 no.4
• /
• pp.451-459
• /
• 1999

Background : In sepsis, excessive generation of reactive oxygen species plays key roles in the pathogenesis of acute lung injury. The serum antioxidants such as catalase and MnSOD are elevated in sepsis and considered as predictors of acute respiratory distress syndrome(ARDS) and prognostic factors of sepsis. Peroxiredoxin(Prx) has recently been known as an unique and major intracellular antioxidant. In this study, we evaluated the expression of Prx I and Prx II in mouse monocyte-macrophage cells(RAW 267.7) after treatment of oxidative stress and endotoxin and measured the amount of Prx I, Prx II and thioredoxin(Trx) in peritoneal and bronchoalveolar lavage fluid of septic animal model. Methods : Using immunoblot analysis with specific antibodies against Prx I, Prx II and Trx, we evaluated the distribution of Prx I and Prx II in human neutrophil, alveolar macrophage and red blood cell. We evaluated the expression of Prx I and Prx II in mouse monocyte-macrophage cells after treatment of $5\;{\mu}M$ menadione and $1\;{\mu}g/ml$ lipopolysaccharide(LPS) and measured the amount of Prx I, Prx II and Trx in peritoneal lavage fluid of intraperitoneal septic animals(septic animal model induced with intraperitoneal 6 mg/Kg LPS injection) and those in bronchoalveolar lavage fluid of intraperitoneal septic animals and intravenous septic animals(septic animal model induced with intravenous 5 mg/Kg LPS injection) and compared with the severity of lung inflammation. Results : The distribution of Prx I and Prx II were so different among human neutrophil, alveolar macrophage and red blood cell. The expression of Prx I in mouse monocyte-macrophage cells was increased after treatment of $5\;{\mu}M$ menadione and $1\;{\mu}g/ml$ lipopolysaccharide but that of Prx II was not increased. The amount of Prx I, Prx II and Trx were increased in peritoneal lavage fluid of intraperitoneal septic animals but were not increased in bronchoalveolar lavage fluid of intraperitoneal and intravenous septic animals regardless of the severity of lung inflammation. Conclusion : As intracellular antioxidant, the expression of Prx I is increased in mouse monocyte-macrophage cells after treatment of oxidative stress and endotoxin. The amount of Prx I, Prx II and Trx are increased in local inflammatory site but not increased in injured lung of septic animal model.

• KDI Journal of Economic Policy
• /
• v.30 no.2
• /
• pp.185-223
• /
• 2008

This paper considers a heterogeneous agent dynamic general equilibrium model and analyzes effects of an increase in labor income tax rate on labor market and the aggregate variables in Korea. The fiscal policy regarding how the government uses the additional tax revenue may take the two forms: 1) general transfer and 2) earned income tax credit (EITC). The model features are as follows: 1) Workers are heterogeneous in their productivity. 2)Labor is indivisible, hence the analysis focuses on the variation in labor supply through the extensive margin in response to a change in fiscal policy. 3) The incomplete markets are introduced, so individual workers can not perfectly insure themselves against risks related to stochastic changes in income or employment status. 4) The model is of general equilibrium, hence it is equiped to analyze the feedback effect of changes in aggregate variables on individual workers' decisions. In the case of general transfer policy, the government equally distributes the additional tax revenue to all workers regardless of their employment states. Under this policy, an increase in the labor income tax rate dampens work incentives of individual workers so that the aggregate employment rate decreases by 1% compared with the benchmark economy. In the case of EITC policy, only employed workers whose labor incomes are below a certain EITC ceiling are eligible for the EITC benefits. Unlike the general transfer policy, the EITC induces low-income workers to participate the labor market to be eligible for EITC benefits. Hence, the aggregate employment rate may increase by 2.7% at the maximum. As the EITC ceiling increases, too many workers can collect the EITC but the benefits per worker becomes too little so that the increase in employment rate is negligible. By and large, this study demonstrates that EITC may effectively raise the aggregate employment rate, and that it can be a useful policy tool in response to the decrease in the labor force due to population aging as observed in Korea recently.

• 한국벤처창업학회:학술대회논문집
• /
• 2010.08a
• /
• pp.139-160
• /
• 2010

On July 21st in 2005, People's Bank of China (PBOC) turned the currency peg against the U.S. dollar into managed currency system based on a basket of unnamed currencies under China's exchanged rate regime. This change means that China's enterprises are not free from currency fluctuations. The purpose of this study is to analyze the relations between Renminbi fluctuations in the floating exchange rate and financial results of venture companies. The process and outcomes of this study are as follows, First, in order to measure the financial results of venture companies, I choose venture companies in Shandong Province listed on the Shanghai Stock Exchange (SSE) at random and several quarter financial sheets according to safety ratios, profitability ratios, growth ratios, activity ratios. Second, I arrange the daily Renminbi exchange rate data announced from July 21st, 2005 to December 31st, 2008 by PBOC into the quarterly data. Third, in order to confirm the relations between Renminbi fluctuations and financial results of venture companies, I carry out Pearson's correlation analysis. As a result, the revaluation of the Chinese Renminbi has weakly negative effects on debt ratio, total assets turnover ratio and equity turnover ratio in statistics. But the revaluation of the Chinese Renminbi is not related to other financial index in statistics. The result of this study is that the revaluation of the Chinese Renminbi has little influence on the export and import of Chinese venture companies and certifies the fact that Chinese venture companies have much foreign currency assets. In addition to avoid the currency exposure risk, this study shows the effective method about currency exposure risk which adjusts proportion of Renminbi to foreign currency.

• Research in Plant Disease
• /
• v.21 no.2
• /
• pp.58-66
• /
• 2015

This study was conducted to evaluate control efficacy of a fermented food 'Cheonggukjang' against cucumber powdery mildew caused by Sphaerotheca fuliginea in greenhouse. Sterilized Daepung beans were inoculated with the rice straw as natural inoculum and then incubated for 72 hrs at $42^{\circ}C$ in the household cheonggkjang maker. After 72 hrs of cheonggukjang fermentation, white zymogens were grown on the surface of a sterile Daepung beans. The pH of the 72 hrs fermented soybean was not significantly changed and electrical conductivity was found to increase by about 2 times than before fermentation. The population density of soybean zymogen showed a peak of growth at 60 hrs after fermentation and the concentration of zymogen was $8.2{\times}10^7cfu/ml$. Soybean zymogen form of the colony was divided into three kinds of bacteria and a white and a large colony (WL) was predominant bacteria among those up to 60 hrs of fermentation. To control the cucumber powdery mildew, diluted solutions of cheonggukjang was applied from 6.0% to 30.0% on cucumber leaves and they showed injury symptoms on cucumber leaves in more than 15% of them. However, more than 6.0% diluted cheonggukjang solutions showed more than 77.8% control effect of cucumber powdery mildew at 15 days after treatment. The fermented bacteria of Chenggukjang were well established in the cucumber leaf area at 15 days after treatment. The antifungal activity of 10% diluted cheonggukjang solutions was excellent for four species of plant fungal pathogens, Colletotrichum gloeosporioides, Sclerotinia cepivorum, Rhizoctonia sloani and Phytophthora capsici in the dual culture test. Results indicated that foliar application of Cheonggukjang solution could be used for the control of powdery mildews occurring on organically cultivated cucumber.