• Asian-Australasian Journal of Animal Sciences
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• v.24 no.2
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• pp.285-294
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• 2011

The abatement of methane emission from ruminants is an important global issue due to its contribution to greenhouse gas with carbon dioxide. Methane is generated in the rumen by methanogens (archaea) that utilize metabolic hydrogen ($H_2$) to reduce carbon dioxide, and is a significant electron sink in the rumen ecosystem. Therefore, the competition for hydrogen used for methanogenesis with alternative reductions of rumen microbes should be an effective option to reduce rumen methanogenesis. Some methanogens parasitically survive on the surface of ciliate protozoa, so that defaunation or decrease in protozoa number might contribute to abate methanogenesis. The most important issue for mitigation of rumen methanogenesis with manipulators is to secure safety for animals and their products and the environment. In this respect, prophylactic effects of probiotics, prebiotics and miscellaneous compounds to mitigate rumen methanogenesis have been developed instead of antibiotics, ionophores such as monensin, and lasalocid in Japan. Nitrate suppresses rumen methanogenesis by its reducing reaction in the rumen. However, excess intake of nitrate causes intoxication due to nitrite accumulation, which induces methemoglobinemia. The nitrite accumulation is attributed to a relatively higher rate of nitrate reduction to nitrite than nitrite to ammonia via nitroxyl and hydroxylamine. The in vitro and in vivo trials have been conducted to clarify the prophylactic effects of L-cysteine, some strains of lactic acid bacteria and yeast and/or ${\beta}$1-4 galactooligosaccharide on nitrate-nitrite intoxication and methanogenesis. The administration of nitrate with ${\beta}$1-4 galacto-oligosaccharide, Candida kefyr, and Lactococcus lactis subsp. lactis were suggested to possibly control rumen methanogenesis and prevent nitrite formation in the rumen. For prebiotics, nisin which is a bacteriocin produced by Lactococcus lactis subsp. lactis has been demonstrated to abate rumen methanogenesis in the same manner as monensin. A protein resistant anti-microbe (PRA) has been isolated from Lactobacillus plantarum as a manipulator to mitigate rumen methanogenesis. Recently, hydrogen peroxide was identified as a part of the manipulating effect of PRA on rumen methanogenesis. The suppressing effects of secondary metabolites from plants such as saponin and tannin on rumen methanogenesis have been examined. Especially, yucca schidigera extract, sarsaponin (steroidal glycosides), can suppress rumen methanogenesis thereby improving protein utilization efficiency. The cashew nutshell liquid (CNSL), or cashew shell oil, which is a natural resin found in the honeycomb structure of the cashew nutshell has been found to mitigate rumen methanogenesis. In an attempt to seek manipulators in the section on methane belching from ruminants, the arrangement of an inventory of mitigation technologies available for the Clean Development Mechanism (CDM) and Joint Implementation (JI) in the Kyoto mechanism has been advancing to target ruminant livestock in Asian and Pacific regions.

• Journal of Nutrition and Health
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• v.40 no.sup
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• pp.3-8
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• 2007

Sugars are a ubiquitous component of our food supply and are consumed as a naturally occurring component of many foods and as additions to foods during processing, preparation, or at the table. Most fruits and dairy products are high in sugars and thus naturally occurring sugars are consumed as part of a healthy diet. Some countries developed recommended daily intake figures(daily values : DVs or guideline daily amounts: GDA) for nutrients, and some countries, but not most have developed DV/GDA for total sugars. Dietary Reference Intakes for Koreans established by the Korean Nutrition Society in 2005, did not include the reference values for total sugar or added sugar. The committee on Dietary Reference Intakes for sugar was constituted in 2006 and discussed whether to special added sugars or total sugar. Although added sugars are not chemically or physiologically different from naturally occurring sugars, many foods and beverages that are major sources of added sugars have lower micronutrient densities compared with foods and beverages that are major sources of naturally occuring sugars. But it was so hard to calculate a dietary intake of added sugar for Korean people, because there was insufficient information about contents of added sugar during processing or preparation of Korean food. Currently Korean or US food labels contain information on total sugars per serving but do not distinguish between sugars naturally present in food and added sugars. Therefore the committee decided to set the reference value for total sugar for Koreans. According to the recommended diet pattern for Koreans suggested by the Korean Nutrition Society, estimated sugar intake from the sugar containing food based on 2,000 kilocalories is 67 g or 13% of total energy. Based on the data available on risk of obesity, hypertension, hyperlipidemia, insulin resistance, and metabolic syndrome from the analysis of Korean NHANES, it was insufficient evidence to set a UL for total sugar, but tended to increase serum LDL cholesterol and obesity at over 20-25% of energy from total sugar when consumed with high carbohydrates. Therefore the committee on Dietary Reference Intakes for sugar set the Acceptable Macronutrient Distribution Range for total sugar as 10-20% of total energy intake.

• Journal of Nutrition and Health
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• v.40 no.3
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• pp.259-269
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• 2007

Recently, dietary pattern analysis was emerged as an approach to examine the relationships between diet and risk of chronic diseases. This study was to identify groups with population who report similar dietary pattern in Korean genome epidemiology study (KoGES) and association with several chronic diseases. The cohort participants living in Ansung and Ansan (Gyeonggi province) were totally 10,038. Among those, 6,873 subjects with no missing values in food frequency questionnaire were included in this analysis. After combining 103 food items into 17 food groups, 4 dietary factors were obtained by factor analysis based on their weights. Factor 1 showed high factor loadings in vegetables, mushrooms, meats, fish, beverages, and oriental-cereals. Factor 2 had high factor loadings in vegetables, fruits, fish, and factor 3 had high factor loadings in cereal-oriental, cerial-western and snacks. Factor 4 showed positive high factor loadings in rice and Kimchi and negative factor loadings in mushrooms and milk and dairy products. Using factor scores of four factors, subjects were classified into 3 clusters by K-means clustering. We named those 'Rice and Kimchi eating' group, 'Contented eating' group, and 'Healthy and light eating' group depending on their eating characteristics. 'Rice and Kimchi eating' group showed high prevalence in men, farmers and 60s. 'Contented eating' group and 'Healthy and light eating' group had high prevalence in women, people living in urban area (Ansan Citizen), with high-school education and above, and a monthly income of one million won and more. 'Contented eating' group appeared lower distribution proportion in the sixties and 'Healthy and light eating' group does higher in the fifties. 'Contented eating' versus 'Rice and Kimchi eating', odds ratio for hypertension, diabetes, metabolic syndrome and obesity significantly decreased after adjusting age and sex (OR=0.64, 0.73, and 0.85 respectively, 95% CI). Although our results were from a cross-sectional study, these imply that the dietary patterns were related to diseases.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.293-296
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• 1979

The effects of temperature and salinity on tile rates of ammonia and amino nitrogen excretion, and oxygen consumption were measured for Crassostrea gigas. There was variability with temperature and salinity changes in both the rates of nitrogen excretion and the proportionality between ,ammonia and amino acids in the excreta, and also in the rates of oxygen consumption. Rates of nitrogen excretion and oxygen consumption were markedly decreased with increase in salinity, especially at high salinity-high temperature, whereas at low salinity-high temperature condition they were significantly increased. These changes are considered as the responses of physiological tolerances to the high temperature stress and the results of the metabolic temperature compensation at the low salinity-high temperature condition. Most of nitrogenous excretory products was ammonia, and large amounts of amino-nitrogen was excreted, and especially the rate of amino-nitrogen excretion was dominant at $32.5\%_{\circ}-22^{\circ}C$. The amounts of amino-nitrogen excreted by animals were decreased in the medium of high salinity and increased in the medium of low salinity through the experimental temperature. The atomic ratios of oxygen consumed to ammonia-nitrogen excreted (O: N ratio) was low at the low temperature $(15^{\circ}C)$, and was high at $22^{\circ}$ and $29^{\circ}C$ in the medium of 32.5 and $37.5\%_{\circ}$ but low in the low salinity $27.5\%_{\circ}$.

• Microbiology and Biotechnology Letters
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• v.42 no.1
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• pp.41-50
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• 2014

In this study, the performances of PVA-encapsulation and non-encapsulation in a fed-batch bioreactor system were compared for biohydrogen production. Hydrogen production in the PVA-encapsulation bioreactor was not significantly different in comparison to the non-encapsulation bioreactor. However, the hydrogen gas in the encapsulation bioreactor could be stably produced when it was exposed to environmental difficulties such as pH impact by the accumulation of organic acids as fermentative metabolic products. Bacterial communities by DGGE analysis were differently shifted between the PVA-encapsulation and non-encapsulation bioreactors from the initial sludge. The community of hydrogen producing bacteria was stable during the experimental period in the PVA-encapsulation bioreactor compared to the non-encapsulation method. The absolute quantitation of the DNA copy number by a high-throughput droplet digital PCR system for six genera contributed to hydrogen production showing that the numbers of dominant bacteria existed at similar levels in the two bioreactors regardless of encapsulation. In both of two bioreactors, not only Clostridium and Enterobacter, which are known as anaerobic hydrogen producing bacteria, but also Firmicutes, Ruminococcus and Escherichia existed with $1{\times}10^5-1{\times}10^6$ copy numbers of ml-samples exhibiting rapid growth during the initial operation period.

• Journal of Applied Biological Chemistry
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• v.64 no.4
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• pp.383-389
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• 2021

Obesity is associated with impaired intestinal epithelial barrier function, which contribute to host systemic inflammation and metabolic dysfunction. Korean traditional foods, fiber-rich bean products, have been various biological activities in anti-inflammatory responses, but has not reported the large intestinal health. In this study, we investigated the intestinal health promoting effect of cooked soybeans (CSB) on high fat diet (HFD)-induced obesity model. SD rat were fed either a HFD or HFD supplemented with 10.6% CSB (HFD+CSB) for animal experimental period. CSB treatment significantly decreased the HFD-induced weights of body and fat. Also, CSB treatment improved HFD-reduced tight junction components (ZO-1, Claudin-1, and Occludin-1) mRNA expression in large intestine tissue. Additionally, histopathological evaluation showed that CSB treatment attenuated the HFD-increased inflammatory cells infiltration and epithelial damages in large intestine tissue. At the genus level, effects of CSB supplement not yet clear, while dietary effects showed differential abundance of several genera including Lactobacillus, Duncaniella, and Alloprevotella. NMDS analysis showed significant microbial shifts by HFD, while CSB did not shift gut microbiota. CSB increased the abundance of the genera Anaerotignum, Enterococcus, Clostridium sensu stricto, and Escherichia/Shigella by linear discriminant analysis effect size analysis, while reduced the abundance of Longicatena and Ligilactobacillus. These findings indicate that CSB supplement improves HFD-deteriorated large intestinal health by the amelioration of tight junction component, while CSB did not shift gut microbiotas.

• Korean Journal of Plant Resources
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• v.32 no.3
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• pp.220-227
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• 2019

Stevia rebaudiana (Asteraceae), a perennial plant, has been used as a low-calorie sweetener and is being developed as a therapeutic agent for diabetes, hypertension, myocardial diseases, and microbial infections. Despite the common use of its leaves and stem, the bioavailability of the components present in S. rebaudiana flowers, when used as ingredients of cosmetics, has not been well investigated. Herein, we investigated the antioxidative and antimelanogenic effects of an aqueous extract of S. rebaudiana flowers (Stevia-F). Total flavonoid and phenolic content in Stevia-F were determined to be $8.64{\pm}0.23mg$ of quercetin equivalents/100 g and $631.5{\pm}2.01mg$ of gallic acid equivalents/100 g, respectively. The $IC_{50}$ values of Stevia-F for reducing power, and 2,2-diphenyl-1-picryl-hydrazyl-hydrate radical, hydrogen peroxide, and nitric oxide scavenging activities were 5541.96, 131.39, 466.34, and $10.44{\mu}g/mL$, respectively. Stevia-F showed inhibitory effects on the tyrosinase ($IC_{50}=134.74{\mu}g/mL$) and ${\alpha}$-glucosidase ($IC_{50}=114.81{\mu}g/mL$) activities. No significant cytotoxicity of Stevia-F was observed in B16F10 cells, treated with up to $100{\mu}g/mL$ of the extract for 24 and 48 h (p > 0.05). Stevia-F ($1-100{\mu}g/mL$) suppressed ${\alpha}$-melanocyte stimulating hormone-induced melanin production in B16F10 cells (p < 0.05) and also inhibited the cellular tyrosinase activity (p < 0.05). Overall, our results show that Stevia-F possesses potential for inhibiting tyrosinase and ${\alpha}$-glucosidase activities and has significant antioxidant capacity. The antimelanogenic potential of Stevia-F should extend the usage of S. rebaudiana flowers in the development of skin-whitening products.

• Biomolecules & Therapeutics
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• v.27 no.5
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• pp.492-501
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• 2019

Nitrogen-containing heterocycles such as quinoline, quinazolinones and indole are scaffolds of natural products and have broad biological effects. During the last years those structures have been intensively synthesized and modified to yield new synthetic molecules that can specifically inhibit the activity of dysregulated protein kinases in cancer cells. Herein, a series of newly synthesized isoquinolinamine (FX-1 to 8) and isoindoloquinazolinone (FX-9, FX-42, FX-43) compounds were evaluated in regards to their anti-leukemic potential on human B- and T- acute lymphoblastic leukemia (ALL) cells. Several biological effects were observed. B-ALL cells (SEM, RS4;11) were more sensitive against isoquinolinamine compounds than T-ALL cells (Jurkat, CEM). In SEM cells, metabolic activity decreased with $10{\mu}M$ up to 26.7% (FX-3), 25.2% (FX-7) and 14.5% (FX-8). The 3-(p-Tolyl) isoquinolin-1-amine FX-9 was the most effective agent against B- and T-ALL cells with IC50 values ranging from 0.54 to $1.94{\mu}M$. None of the tested compounds displayed hemolysis on erythrocytes or cytotoxicity against healthy leukocytes. Anti-proliferative effect of FX-9 was associated with changes in cell morphology and apoptosis induction. Further, influence of FX-9 on PI3K/AKT, MAPK and JAK/STAT signaling was detected but was heterogeneous. Functional inhibition testing of 58 kinases revealed no specific inhibitory activity among cancer-related kinases. In conclusion, FX-9 displays significant antileukemic activity in B- and T-ALL cells and should be further evaluated in regards to the mechanisms of action. Further compounds of the current series might serve as templates for the design of new compounds and as basic structures for modification approaches.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.303-308
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• 2019

L-carnitine is found in high levels in muscle tissues. It has been developed as a nutrient and dietary supplement, and also used as a therapeutic supplement in various diseases including type II diabetes, osteoporosis and metabolic neuropathies. However, it is not fully understood how it affects cellular mechanisms in colorectal cancer. Therefore, we attempted to determine the effect of L-carnitine in HCT116 human colorectal cancer cells. First, the HCT116 cells were exposed to L-carnitine for 24 hours at 0-40 mM, and then analyzed for cellular proliferation, oxidative stress and related mechanisms. In a MTT assay, L-carnitine inhibited cellular proliferation and induced reactive oxygen species (ROS) in HCT116 by DCF-DA analysis. To analyze the mechanism of L-carnitine in colorectal cancer cells, we performed a western blot analysis for pERK1/2 and pp38 MAP kinase. The western blot showed that L-carnitine significantly increased protein levels of pERK1/2 and pp38 compared with control. Taken together, we found that L-carnitine has anti-proliferative function via increased ROS and activation of ERK1/2 and p38 pathway in HCT116. These findings suggest that L-carnitine may have an anti-proliferative role on colorectal cancer.

• Journal of Life Science
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• v.31 no.1
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• pp.47-51
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• 2021

In today's society, functional whitening cosmetics are important to beauty. Fungi are known to produce a variety of whitening-related metabolites. In this study, we searched for tyrosinase inhibitors with metabolic products derived from Trichoderma atroviride supernatant in order to apply a material for whitening functional cosmetics. In addition, the inhibitory effect was compared to arbutin, which has already been approved as a whitening raw material by the Korea Ministry of Food and Drug Safety (KMFDS). The metabolites from the T. atroviride supernatant showed higher tyrosinase inhibitory activity than that of arbutin. Some of the tyrosinase inhibitors were stable to heat, whereas some were unstable. The heat unstable material was exhibited in the case of samples treated with little amounts, such as 0.02~0.2%. They were very unstable in acidic and alkali pHs, especially under acidic conditions. However, it was found that a weakly-acidic to neutral pH range was the optimal working pH, especially neutral pH. Since the activity of the inhibitory substances in the T. atroviride supernatant was maintained regardless of proteinase K treatment, it was assumed that the metabolites, but not the bioactive peptides, were involved in the activity. In summary, we propose that the metabolites derived from T. atroviride supernatant have strong potential as whitening raw material.