• Food Science and Preservation
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• v.11 no.3
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• pp.331-335
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• 2004

This study was carried out to improve quality of minimally processed lettuce with various treatments. The treatments for preventing enzymatic browning were using different chemical immersion solutions and controlling microbial growth were using chlorine, electrolyzed water, and organic acid. The solution with ascorbic acid 1$\%$ and citric acid 1 $\%$ showed a positive effect on antibrowning of minimally processed lettuce. In the inhibition of microorganisms growth, 200 ppm NaCIO solution was more effective than fermented pollen solution and Na-dichloroisocyanurate solution. In electrolyzed water system, no-diaphragm system showed inhibitory effect of microorganisms growth. Also, total microorganisms count of minimally processed lettuce with ascorbic acid and citric acid solution was lower by about 4 log cycle after 4 days storage at l0$^{\circ}C$.

• The Korean Journal of Pharmacology
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• v.30 no.1
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• pp.101-109
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• 1994

Pharmacological characterization of GS 283, a tetrahydroisoquinoline derivative has been elucidated using rat thoracic aorta, guinea pig tenea coli and rabbit mesentery artery in vitro. GS 283 showed calcium antagonistic action in vascular smooth muscle, since high $K^+-induced$ contraction was concentration dependently inhibited. GS 283 also inhibited the contraction induced by ${\alpha}_1$ receptor activation. Vasodilating action of GS 283 was not modified by the propranolol, indicating that GS 283 has no ${\beta}$ receptor stimulatory action. Simultaneous measurement of intracellular calcium change and muscle tension indicated that the inhibitory effect of GS 283 was accompanied by the increase in tissue fluorescence. This increment was not due to fura 2 fluorescence but to endogenous pyridine nucleotide, suggesting that GS 283 has an effect to inhibit mitochondrial function. GS 283 had an inhibitory action on cyclic AMP and GMP-dependent phosphodiesterases from rat brain with Ki values of 2.5 and 6.7 mM. From these findings we concluded that GS 283 has multiple action such as the inhibition of cyclic nucleotide-dependent phosphodiesterases, blocking of calcium channel as well as inhibition of mitochondrial function which are responsible for vasodilatation.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.3
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• pp.337-344
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• 2018

Hepatocellular carcinoma (HCC), a major type of hepatoma, is associated with high recurrence and mortality because of its uncontrolled metastatic feature. Silymarin is a polyphenolic flavonoid from Silybum marianun (milk thistle) and exhibits anti-carcinogenic activity through modulation of the epithelial-mesenchymal transition (EMT) in several cancer cells. In this study, the inhibitory mechanism of silymarin against migration and invasion was investigated in the Huh7 HCC cell line. Wound healing and in vitro invasion assays were conducted to examine the effects of silymarin on migration and invasion. Western blot analysis was also applied to evaluate the inhibitory effects of silymarin on the EMT-related genes and their upstream signaling molecules. Silymarin inhibited the migratory and invasive activities of Huh7 cells. In addition, silymarin attenuated the protein expression levels of vimentin and matrix metalloproteinase (MMP)-9 as well as their transcription factors, Snail, and nuclear factor $(NF)-{\kappa}B$, while the expression of E-cadherin was increased by the silymarin treatment. Among the upstream signaling molecules, the phosphorylation of Akt was inhibited by the silymarin treatment, which was confirmed by the selective inhibitor, LY294002. Consequently, silymarin inhibited the invasive and migratory activities in Huh7 cells through the modulation of EMT-related gene expression by the PI3K/Akt signaling pathway, which may have potential as a chemopreventive agent against HCC metastasis.

• Korean Journal of Food Science and Technology
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• v.39 no.1
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• pp.20-24
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• 2007

The effects of phenolic acids on inhibition of browning by the Maillard reaction were investigated with a glucose-glutamic acid model for doenjang with citric acid as the antibrowning agent and phenolic acid as its synergist. Five phenolic acids, cinnamic, coumaric, caffeic, hydroxybenzoic, and protocatechuic acids, were used. In order to investigate the antibrowning capacity, 0.1M glucose, 0.1M glutamic acid, 50mM citric acid, and 1mM phenolic acid were dissolved in 1M phosphate buffer (pH 7.0), heated at $50^{\circ}C$ for 24hr in the presence of 0.2mM $FeCl_{2}$, and stored at $4^{\circ}C$ or $30^{\circ}C$ for four weeks. Phenolic acid addition more efficiently inhibited browning during storage at $30^{\circ}C$ than at $4^{\circ}C$, without changes in pH. Hydroxybenzoic acid was the most efficient and increased the antibrowning capacity by 13% compared to sample without phenolic acids. Although caffeic and protocatechuic acids inhibited most the formation of 3-deoxyglucosone or fluorescence, they increased browning by forming colored complexes between two hydroxy groups of phenolic acids and iron ions. Hydroxybenzoic acid will be able to be a useful synergist of citric acid, an antibrowning agent in doenjang, since it is permitted for doenjang.

• The Korean Journal of Pesticide Science
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• v.10 no.1
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• pp.36-42
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• 2006

For the effective control of pepper anthracnose, in vitro antifungal activities of 13 commercial fungicides were tested on spore germination, mycelial growth, and sporulation of Colletotrichum gloeosporioides, anthracnose fungus. Among them, captan, chlorothalonil, dithianon, fluazinam and folpet completely inhibited the spore germination of C. gloeosporioides at the concentration of 0.8 ${\mu}g/ml$. They were followed by mancozeb and propineb, showing more than 80% inhibition of spore germination at 20 ${\mu}g/ml$. The mycelial growth of C. gloeosporioides was strongly inhibited by fluazinam and nuarimol. Except for nuarimol, most of the fungicides represented more antifungal activity on the spore germination than the mycelial growth of C. gloeosporioides. Azoxystrobin and metominostrobin, Strobilurin fungicides, were only moderately active against the spore germination and the mycelial growth of C. gloeosporioides, but they were effective antisporulant against C. gloeosporioides. From these results, control of pepper anthracnose will have achieved by preventive spray of the commercial fungicides.

• Journal of Life Science
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• v.13 no.5
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• pp.692-698
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• 2003

This study was designed to investigate the effects of ethyl acetate (EtOAc) fraction of pine (Pinus densiflora Sieb et Zucc) needle on membrane fluidity (MF), basal and induced oxygen radical (BOR and IOR), lipid peroxide (LPO) and oxidized protein (OP) as a oxidative stress, and lipofuscin (LF) in brain membranes of Sprague-Dawley (SD) rats. Male SD rats were fed basic diets (control) and experimental diets (EtOAc-25, EtOAc-50 and EtOAc-100) for 45 days. MF was significantly increased (about 10%) in mitochondria of EtOAc-100 group. BOR and IOR formations in mitochondria were significantly inhibited (about 9∼10% and 17∼24%, respectively) in EtOAc-50 and EtOAc-100 groups, while BOR and IOR formations in microsomes were significantly inhibited (about 12∼17% and 12∼16%, respectively) in EtOAc-50 and EtOAc-100 groups compared with control group. LPO levels in mitochondria and microsomes were significantly inhibited (about 9∼l2% and 12∼19%, respectively) in EtOAc-50 and EtOAc-100 groups, whereas significant difference between OP or LF levels and control group in these membranes could not be obtained. These results suggest that administrations of ethyl acetate fraction of pine needle may play an effective role in an attenuating an oxidative stress and in increasing membrane fluidity.

• Journal of Life Science
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• v.19 no.12
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• pp.1808-1814
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• 2009

In our previous study, a new herbal preparation (HemoHIM) was developed as a functional food for the radioprotection and immunomodulatory agents. In order elucidate the mechanism involved, we examined the effect of HemoHIM on the compound 48/80-induced histamine release, and on the phorbol 12-myristate 13-acetate (PMA)/calcium ionophore (A23187)-induced inflammatory cytokine secretion in HMC-1. The cell culture supernatants were harvested, and the cytokines (IL-4, IL-6, IL-8, TNF-$\alpha$, GM-CSF) in the supernatants were measured by enzyme-linked immunosorbent assay. The total RNA of the cells was extracted, and the cytokines or c-kit/tryptase/Fc$\varepsilon$RI's messenger RNA expressions were examined using reverse transcriptase polymerase chain reaction. Under low concentrations, HemoHIM inhibited histamine release in HMC-1 stimulated compound 48/80. Furthermore HemoHIM inhibited PMA/A23187-induced inflammatory cytokines' secreation or mRNA expression in a dose-dependent manner. But IL-8 secretion was not inhibited by low concentrayion of HemoHIM, respectively. The mRNA expression of c-kit and Fc$\varepsilon$RI were also inhibited in a dose-dependent manner. Tryptase mRNA expression was only inhibited by low concentration of HemoHIM. These results indicated that HemoHIM might be an useful agent for protection against allergy as well as immune modulation, especially since it is a relatively nontoxic natural product.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.976-982
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• 2007

The purpose of this study was to determine the modulating effects of histone deacetylase inhibitor, trichostatin A, on the differentiation of mouse C2C12 myoblasts. We demonstrated that trichostatin A induced morphological changes of C2C12 myoblasts into smooth muscles and significantly increased the gene expression of smooth muscle markers including smooth muscle ${\alpha}-actin$ and transgelin. These results were due to the change in the expression level of cell cycle regulators in trichostatin A-treated C2C12 cells. Real-time PCR data revealed that cyclin dependent kinase inhibitor, p21, mRNA expression was significantly increased in trichostatin A-treated C2C12 cells. However, trichostaDn A rapidly decreased cyclin Dl mRNA expression necessary for cell cycle progression in 24hr after treatment. In conclusion, the strong inhibitory effects of trichostatin A on histone deacetylation induced transdifferentiation of C2C12 myoblasts into smooth muscle cells and these results are partly due to the changes in the expression of cell cycle regulators such as p21 and cyclin D1.

• Journal of Life Science
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• v.23 no.10
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• pp.1216-1222
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• 2013

NK cells are lymphoid immune cells that participate in innate immunity to protect against foreign pathogens and transforming cells. It is known that the activity of NK cells is regulated by a balance between activating and inhibitory signals rather than specific antigens. One important activating signal is mediated by the NKG2D receptor, which recognizes NKG2D ligands on cancer cells. Therefore, tumor cells that express sufficient amounts of NKG2D ligands could be eliminated by NKD2D+ cells, including NK cells. Oncogenes drive tumor cells to apoptosis resistant and uncontrolled proliferation by altered expression of many critical genes. Therefore, the expression of NKG2D ligands may be affected by oncogenes. This study focused on increasing the susceptibility of cancer cells to NK cells by regulating the expression of NKG2D ligands influenced by three oncogenes: k-ras, wnt, and c-myc. We demonstrated that inhibition of k-ras and c-myc increased the expression of NKG2D ligands and enhanced the susceptibility of cancer cells to NK cells. On the contrary, inhibition of the wnt pathway decreased MICA and ULBP1 transcripts. Although the decreased transcription of NKG2D ligands by inhibition of the wnt pathway, surface proteins of NKG2D ligands were not changed, and the susceptibility of HCT-116 cells was unaffected. The results demonstrate that the transcription of NKG2D ligands are regulated deferentially by the k-ras, c-myc, and wnt pathways and that the cytotoxicity of NK cells solely depends on the amount of surface NKG2D ligands.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.2
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• pp.155-162
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• 2007

The purpose of this study is to investigate the anti type I allergic effects and mechanisms of the phyto extract mixture (PEM381) which contains Camellia sinensis (leaf), Psidium guajava (leaf), and Rosa hybrida (flower). PEM381 was tested for its inhibitory effects on arachidonic acid cascade related enzymes (5-lipoxygenase and cyclooxygenase), the mast cell mediated allergic reaction and passive cutaneous anaphylaxis. $IC_{50}$ value of PEM381 against 5-lipoxygenase was $14.11{\pm}0.51ppm$ while that of positive control (nordihy-droguaiaretic acid) was $0.54{\pm}0.08ppm$. PEM381 also exhibited considerable selective inhibition of cyclooxygenase-2. PEM381 could inhibit both degranulation and histamine release in a dose dependent manner from rat peritoneal mast cells activated by compound 48/80. In addition, oral administration of PEM381 showed an inhibitory effect on passive cutaneous anaphylaxis reaction activated by anti-dinitrophenyl IgE antibody in mice. These results suggest that PEM381 may be useful for the prevention and treatment of type Ⅰ allergy related diseases.