• Journal of Life Science
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• v.21 no.7
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• pp.1046-1051
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• 2011

Diallyl disulfide (DADS), the most prevalent oil-soluble organosulfur compound in garlic, is known to have diverse biological activities, including anticarcinogenic, antiatherosclerotic, antiinflammatory, and antioxidant actions. In this study, we investigated the effect of DADS on the expression of heme oxygenase-1 (HO-1) in human liver hepatoma cell line HepG2. Treatment of HepG2 cells by DADS evoked a dose-dependent growth inhibition without significant toxicity to the cells, and also induced the expression of transcription factor Nrf2. However, DADS did not have any enhancing effect on transcription and translation of HO-1 expression in HepG2 cells. In addition, DADS efficiently blocked protein synthesis of HO-1 in HepG2 cells stimulated by CoPP or hemin. But, DADS did not decrease the content of transcripts of HO-1 gene stimulated by CoPP, with accumulation of Nrf2 and small Maf in the nucleus. Based on these results, we conclude that DADS inhibits HO-1 expression by modulation of translational level of CoPP or hemin-induced HO-1 expression in HepG2 cells.

• Journal of Life Science
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• v.20 no.1
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• pp.82-89
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• 2010

This study was investigated to analyze the contents of flavonoid compounds and the effects of fermentation on the physiological activities of medical plants, also known as SanYa (SY). Antioxidative activity of the fermented SanYa (FSY) was measured by using DPPH radical scavenging and SOD-like activity. DPPH radical scavenging and SOD-like activity of FSY were 94.3% and 45.0%, respectively. Nitric oxide (NO) synthesis was increased 11 times through the addition of FSY. However, NO production of the macrophages RAW264.7 cells stimulated with lipopolysaccharide (LPS) was reduced to 56% through the addition of FSY. FSY showed fibrinolytic activity and indicated about 69.8% and 73.7% of xanthine oxidase and angiotensin converting enzyme inhibitory activities, respectively. These results suggested that FSY plays a significant role in fibrinolytic activity and have strong xanthine oxidase and angiotensin converting enzyme inhibitory activities.

• Journal of Life Science
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• v.20 no.11
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• pp.1617-1624
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• 2010

Recently, it has been found that Asiasari radix showed a hypopigmenting effect on melanogenesis through activation of mitogen-activated protein kinase (MEK)/extracellular signal-activated kinase (ERK) in B16F10 melanoma cells. However, the hypopigmenting effect of A. radix on the $\alpha$-melanocyte stimulating hormone ($\alpha$-MSH)-stimulated melanogenesis has remained unknown. The purpose of this study was to investigate the inhibitory mechanism of the partially purified A. radix (PPAR)-induced hypopigmentating effects on $\alpha$-MSH-stimulated melanogenesis in B16F10 mouse melanoma cells. PPAR strongly inhibited tyrosinase activity and leads to decreased melanin synthesis in $\alpha$-MSH-stimulated B16F10 melanoma cells. PPAR also decreased the $\alpha$-MSH-induced over-expression of the melanogenic enzymes, tyrosinase, tyrosinase-related protein (TRP)-1, dopachrome tautomerase (Dct) and microphthalmia-associated transcription factor (MITF). We further showed that PPAR inhibits $\alpha$-MSH-induced melanogenesis via phosphorylation of MEK/ERK and PI3K/Akt, and that their activation was blocked by MEK inhibitors, PD98059 and PI3K inhibitors, LY294002 in $\alpha$-MSH-stimulated B16F10 melanoma cells. These results suggest that PPAR inhibits $\alpha$-MSH-induced melanogenesis by activation of MEK/ERK and PI3K/Akt through MITF degradation, which may lead to down-regulation of tyrosinase.

• Journal of Life Science
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• v.27 no.11
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• pp.1381-1392
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• 2017

This review described solvent-tolerant lipases and their potential industrial, biotechnological and environmental impacts. Although organic solvent-tolerant lipase was first reported in organic solvent-tolerant bacterium, many organic solvent-tolerant lipases are in not only solvent-tolerant bacteria but also solvent-intolerant bacterial and fungal strains, such as the well-known Bacillus, Pseudomonas, Streptomyces and Aspergillus strains. As these lipases are not easily inactivated in organic solvents, there is no need to immobilize them in order to prevent an enzyme inactivation by solvents. Therefore, the solvent-tolerant lipases have the potential to be used in many biotechnological and biotransformation processes. With the solvent-tolerant lipases, a large number insoluble substrates become soluble, various chemical reactions that are initially impossible in water systems become practical, synthesis reactions (instead of hydrolysis) are possible, side reactions caused by water are suppressed, and the possibility of chemoselective, regioselective and enantioselective transformations in solvent and non-aqueous systems is increased. Furthermore, the recovery and reuse of enzymes is possible without immobilization, and the stabilities of the lipases improve in solvent and non-aqueous systems. Therefore, lipases with organic-solvent tolerances have attracted much attention in regards to applying them as biocatalysts to biotransformation processes using solvent and non-aqueous systems.

• Journal of Life Science
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• v.30 no.7
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• pp.640-650
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• 2020

Fibroblast growth factor 21 (FGF21) is an atypical member of the FGF protein family which is highly synthesized in the liver, pancreas, and adipose tissue. Depending on the expression tissue, FGF21 uses endo- or paracrine features to regulate several metabolic pathways including glucose metabolism and energy homeostasis. Different physiologically stressful conditions such as starvation, a ketogenic diet, extreme cold, and mitochondrial dysfunction are known to induce FGF21 synthesis in various tissues to exert either adaptive or defensive mechanisms. More specifically, peroxisome proliferator-activated receptor gamma and peroxisome proliferator-activated receptor alpha control FGF21 expression in adipose tissue and liver, respectively. In addition, the pharmacologic administration of FGF21 has been reported to decrease the body weight and improve the insulin sensitivity and lipoprotein profiles of obese mice and type 2 diabetes patients meaning that FGF21 has attracted huge interest as a therapeutic agent for type 2 diabetes, obesity, and non-alcoholic fatty liver disease. However, understanding FGF21 remains complicated due to the paradoxical condition of its tissue-dependent expression. For example, nutrient deprivation largely increases hepatic FGF21 levels whereas adipose tissue-derived FGF21 is increased under feeding condition. This review discusses the issues of interest that have arisen from existing publications, including the tissue-specific function of FGF21 and its action mechanism. We also summarize the current stage of a clinical trial using several FGF21 analogs.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.797-802
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• 2003

Structured lipids (SL) were synthesized by esterification of corn oil and conjugated linoleic acid (CLA) in a continuous packed-bed column reactor. The effects of flow rate, reaction temperature, and substrate molar ratios were studied. The reaction was catalyzed by TL IM (immobilized lipase from Thermomyces lanuginosa). Results of triacylglycerol (TAG) analysis by GC showed that the incorporated CLA isomers were mainly cis9, trans11- and trans 10, cis12-CLA. Slower flow rates yielded higher incorporation, and maximum incorporation of CLA was obtained with a molar ratio of 1:3 (corn oil: CLA) at a temperature of $55^{\circ}C$. The obtained SLs had iodine values ranging from 120 to 128. The SLs were composed of TAG $(98{\sim}99%)$, 1,2- and 1,3-diacylglycerol ($0.7{\sim}1.3%$), and a small amount of monoacylglycerol.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.6
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• pp.582-590
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• 1987

Plasteins were synthesized from a peptic filefish protein hydrolysate by papain, $\alpha-chymotrypsin$ and protease(from Streptomyces griceus) under the optimum conditions of previous paper. L-glutamic acid diethylester and L-leucine ethylester were incorporated into plastein during the plastein reaction by papain. The structural changes of freeze-dried filefish meat, peptic hydrolysate, FPC and plasteins were observed by Scanning Electron Microscopy(SEM). The functional properties of plasteins also were measured. The solubility of plasteins was higher than that of FPC and the Glu-plastein had $95\%$ solubility in the range of pH 3-10. The dispersibility of Glu-plastein and protease plastein was similar to that of egg albumin, but those of the other plasteins were lower. The water holding capacity of plasteins was lower than that of egg albumin and C. Lipid absorption of Leu-plastein was tile highest, holding 1.80 ml/g, and that of the other plasteins was similar to that of egg albumin. The emulsifying activity of Leu-plastein was the highest, holding $61.2\%$, and that of Glu-plastein was the lowest, holding $50.7\%$. The emulsifying stability of plasteins was similar to that of the emulsifying activity. The emulsifying capacity of Leu-plastein was 384 ml/g(the highest), but that of Glu-plastein and $\alpha-chymotrypsin$ plastein was 248 ml/g(the lowest). The Leu-plastein shelved the highest foaming capacity, $373\%$. The foaming capacity of other plasteins was higher than that of egg albumin. The foaming stability of plasteins was superior to that of egg albumin. The viscosity of plasteins was lower than that of egg albumin. The microstructure of $\alpha-chymotrypsin$ plastein by SEM wassimilar to that of papain plastein, but other plasteins showed differences in their microstructure. The microstructure of Glu-plastein had a smooth shape.

• KSBB Journal
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• v.20 no.2 s.91
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• pp.112-115
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• 2005

E. coli in combination with bacteriophage $\lambda$ was used to overcome the intrinsic plasmid instability that is frequently found in recombinant fermentation especially in long-term operation. In order to enhance the stability and productivity, the bacteriophage ${\lambda}NM1070$ was used in this study. It is a $\lambda$ mutant, which is deficient in the synthesis of protein related to DNA packaging and cell lysis. The ${\lambda}NM1070$ is also a temperature-sensitive mutant. To optimize the production of recombinant protein in this temperature-sensitive system, the temperature effects on growth and cloned gene expression were investigated for stable and efficient recombinant gene expression. The induction to the lytic state was not complete at $36^{\circ}C$ while the temperature above $40^{\circ}C$ induced the lytic state completely. However, the productivity was decreased at $42^{\circ}C$ by temperature inhibition. The L-free cell concentration increased with the increase of temperature until $40^{\circ}C$. In conclusion, ${\lambda}NM1070$ has the optimal temperature at $38^{\circ}C$ for stability and at $40^{\circ}C$ for expression.

• KSBB Journal
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• v.29 no.1
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• pp.58-66
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• 2014

Demand for in vitro pharmacological evaluation and toxicity test using human hepatocytes has been increasing. In USA and Europe, human hepatocytes obtained from donated whole liver unsuitable for transplantation were distributed to researchers and deposited in cell bank facility as cryopreserved vial. In Korea, however, incidence of transplantation- inappropriate whole liver has been quite low and the whole livers almost have so severe liver disease such as fatty or fibrotic liver that cannot meet the demand. In this study we aimed to isolate human hepatocytes from liver resection surgery-originated partial liver, and assure the isolated human hepatocytes and its cryopreserved hepatocytes to be qualified for the in vitro pharmacological evaluation and drug toxicity tests. We compared those with commercially available human hepatocyte, BD $GenTest^{TM}$ by cell morphology, hepatic gene expression, urea synthesis, albumin secretion, ammonia removal, and cytochrome P450 induction activities. Changes in hepatotoxic gene expression after cryopreservation are evaluated with a typical hepatotoxic drug, acetaminophen. Consequently, the fresh hepatocytes from the partial liver and its cryopreserved hepatocytes expressed their intrinsic hepatic functions well and showed equal hepatotoxicity gene expression trend regardless to cryopreservation. Therefore, liver resection surgery-originated partial liver can be used as a useful source of human hepatocytes for various pharmacological and hepatotoxicity test.

• Journal of Periodontal and Implant Science
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• v.36 no.3
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• pp.745-755
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• 2006

The purpose of this study was to investigate the effects of irradiated frozen allogenic bone(IFAB) on the cell proliferation and differentiation of human fetal osteoblasts. Human fetal osteoblasts(hFOB1) were cultured to examine the cellular proliferation for 3 days and 5 days with $1mg/m{\ell}$, $100{\mu}g/m{\ell}$, $10{\mu}g/m{\ell}$, $1{\mu}g/m{\ell}$, $100ng/m{\ell}$, $10ng/m{\ell}$, $1ng/m{\ell}$ of IFAB, and to compare the ALP synthesis to control groups for 3 days with DMEM/F-12 1:1 Mixture and $1mg/m{\ell}$, $100{\mu}g/m{\ell}$, $10{\mu}g/m{\ell}$, $1{\mu}g/m{\ell}$, $100ng/m{\ell}$, $10ng/m{\ell}$, $1ng/m{\ell}$ of IFAB. To compare the calcium accumulation, hFOBl cultured for 23 days were quantified and photographed. The cellular proliferation of hFOBls treated with IFAB was increased at 5 days to control(p<0.05). The activity of ALP in hFOBls treated with $100ng/m{\ell}$ IFAB was significantly increased at 5 days(p<0.05). A quantified calcium accumulation in hFOBl was significantly increased at $100ng/m{\ell}$, $10ng/m{\ell}$ of IFAB(p<0.05). In the present study, we found that IFAB playa important role of bone formation in the early stage. There was considered that IFAB could be used in the bone graft material.