• Microbiology and Biotechnology Letters
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• v.42 no.3
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• pp.312-315
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• 2014

So as to evaluate its use an immune stimulator in humans, the toxicity and action against immune cells by an anti-yeast substance (AYS), a bacterial proteoglycan, were investigated. The AYS did not possess hemolytic activity with human red blood cells (hRBC). Nor did it exhibit cytotoxicity against human peripheral blood mononuclear cells (hPBMC). In addition, the AYS did not induce hPBMC proliferation, but it did agglutinate hPBMCs in vitro. Moreover, hPBMC induced inflammatory cytokines such as IL-6, IL-5, IFN-${\gamma}$ and TNF-${\alpha}$ with the AYS during culture. Compared with alum, the AYS as an adjuvant has an increased antibody production rate against bovine serum albumin (BSA) in mice.

• Bulletin of the Korean Chemical Society
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• v.25 no.12
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• pp.1863-1868
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• 2004

Kringle 5 (K5), located outside of angiostain (K1-4) in human plasminogen, displays more potent antiangiogenic activity on endothelial cell proliferation than angiostatin itself. Using a yeast two-hybrid system in vivo, we have recently identified Rgl2 (guanine nucleotide dissociation stimulator (RalGDS)-like factor 2) as a binding protein of human K5. In order to confirm in vitro protein interaction between K5 and Rgl2, we developed bacterial recombinant expression systems for them. K5 and Rgl2 proteins were expressed in high yields and purified into pure forms with His tags and GST fusion, respectively. GST-pull down experiments clearly demonstrated that K5 interacts specifically with Rgl2 in vitro. These results indicate that Rgl2 functions as a receptor protein for K5 in vitro as well as in vivo, leading to anti-angiogenesis through regulating Ras signaling pathways.

• Particle and aerosol research
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• v.18 no.2
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• pp.37-50
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• 2022

Due to the syndrome coronavirus 2 (SARS-CoV-2) pandemic, the subway passenger cabin should be continuously sterilized. However, a disinfectant such as chlorine is toxic and can lead to different issues to human health. In this paper, we introduced a novel disinfectant based on natural product (Dendropanax morbifera extract). Via ultra-high performance liquid chromatography - mass spectrometer (UHPLC-MS), different compounds from Dendropanax morbifera extract showed antivirus potentials. Antimicrobial experiments confirmed that the air-disinfectant containing Dendropanax morbifera can eliminate harmful microorganisms including Gram (-), Gram (+), and yeast within 5 mins. The as-prepared air-disinfectant also showed high antivirus activity against H1N1, HRV, and EV71. Deodorization test also indicates that the as-prepared air-disinfectant can lower the harmful gas such as ammonia and trimethylamine in the atmosphere. To evaluate the potential of air-disinfectant containing Dendropanax morbifera in practical applications, different safety tests including acute oral toxicity, acute skin irritation, and eye irritation were conducted. Results showed that the as-prepared disinfectant did not negatively affect tested animals during these safety investigations.

• Microbiology and Biotechnology Letters
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• v.42 no.3
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• pp.219-224
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• 2014

In order to develop a new anti-diabetic ${\alpha}$-glucosidase inhibitor, we compared the ${\alpha}$-glucosidase inhibitory activity of the cell-free extracts of 48 strains of yeasts isolated from Korean fermented foods, and found that Pichia burtonii Y257-7 exhibited the highest ${\alpha}$-glucosidase inhibitory activity of 55.6%. The ${\alpha}$-glucosidase inhibitor was maximally produced when Pichia burtonii Y257-7 was cultured in LB broth (initial pH of 6.0) at $28^{\circ}C$ for 24 h. The ${\alpha}$-glucosidase inhibitor, partially purified by Sephadex G-50 gel permeation chromatography and systematic solvents extraction, revealed potent hypoglycemic effects in normal rats and streptozotocin-induced diabetic rats after the oral administration of starch.

• KSBB Journal
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• v.19 no.2
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• pp.118-124
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• 2004

Melanocytes synthesize melanin within discrete organelle termed melanosomes which are transferred to the surrounding keratinocytes and can be produced in varying sizes, numbers and densities. Skin whitening products have become increasingly popular in the past few years. The most successful natural skin whitening agents are: Arbutin, Vitamin C, Kojic acid, Mulberry, which are all tyrosinase inhibitors. In this work, melanoston, a melanogenesis inhibitor isolated from yeast was studied to understand its mechanism of melanogenesis inhibition. It was found that melanoston was not a tyrosinase inhibitor, while when melanoston was applied to the B16 melanoma cell culture media, the intracellular tyrosinase activity was decreased by more than 30％, When B16 melanoma was stimulated with ${\alpha}$-MSH, cell morphololgy was dramatically changed to have lots of dendrites on the cell membrane surface. On the other hand, B16 was treated with ${\alpha}$-MSH and melanoston, simultaneously, the change of cell morphology was not so great. This inhibition effect of melanoston was found to be related to the inhibition of intracellular activation and transportation of tyrosinase, which was observed by immunostaining of B16 melanoma using anti-tyrosinase antibody. From these results, melanoston was regarded as an inhibitor to the differentiation of melanoma cells.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.589-595
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• 2001

Effect of anti-microbial agents, such as alcohol, garlic, chitosan, K-sorbate, or mustard, or pasteurization on the quality of traditional kochujang was investigated during storage at $30^{\circ}C$ for 24 weeks. Water activities of kochujang decreased after 12 weeks of storage. Consistency increased during storage and highest consistency of kochujang was obtained by the addition of mustard or garlic. Hunter a- and b-values decreased linearly as storage time passed. The degree of increase in total color difference$({\Delta}E)$ of alcohol added group was the highest among the tested anti-microbial agents. Gas was rapidly produced in the control and chitosan added group of kochujang. Capsanthin content decreased more rapidly in the group of alcohol, garlic or mustard added kochujang than the other group. Viable cell counts of yeast and aerobic bacteria in kochujang increased up to 12 weeks of storage, and then decreased slowly. The number of yeast was low in K-sorbate or alcohol added group. Activity of ${\alpha}-amylase$ decreased during storage, but that of ${\beta}-amylase$ increased in alcohol, garlic, K-sorbate added or pasteurized kochujang. Protease activities did not show any remarkable differences in the groups of tested during storage.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.1 s.49
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• pp.25-33
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• 2005

Melanocytes synthesize melanin within discrete organelle termed melanosomes which are transferred to the surrounding keratinocytes and can be produced in varying sizes, numbers and densities. Skin whitening products have become increasingly popular in the past few years. The most successful natural skin whitening agents are: arbutin, vitamin C, kojic acid, and mulberry, which are all tyrosinase inhibitors. In this work, melanoston, a melanogenesis inhibitor isolated from yeast was studied to understand its mechanism of melanogenesis inhibition. It was found that melanoston was not a tyrosinase inhibitor, while when melanoston was applied to the B16 melanoma cell culture media, the intracellular tyrosinase activity was decreased by more than $30\%$. When B16 melanoma was stimulated with $\alpha$-MSH, cell morphololgy was dramatically changed to have lots of dendrites on the cell membrane surface. On the other hand, B16 was treated with $\alpha$-MSH and melanoston, simultaneously, the change of cell morphologv was not so great. This inhibitory effect of melanoston was found to be related to the inhibition of intracellar activation and transportation of tyrosinase, which was observed by irmmunostaining of B16 melanoma using anti-tyrosinase antibody. From these results, melanoston was regarded as an inhibitor to the differentiation of melanoma cells.

• The Journal of Korean Society of Virology
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• v.28 no.1
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• pp.39-52
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• 1998

HIV-1 tat, a strong transactivator, is essential for the HIV-1 replication and AIDS progression. The Tat function is markedly inhibited by human anti-oncogene p53. This work was initiated to identify the p53-associated inhibitory mechanism on tat-mediated transactivation. Inhibitory function of p53 was confirmed by co-transfection of tat-expressing Jurkat cells with LTR-CAT plasmid, or H3T1 cells (LTR-CAT integrated HeLa cells) with different ratio of pSV-tat/pCDNA-p53 plasmids. Results from the direct protein-protein interaction between soluble p53 and tat, and yeast two-hybrid experiments showed that the co-suppression mechanism is unlikely to be due to the direct interaction. CAT activity was not affected by tat in Jurkat cells which were transfected with p53-promoter-CAT or p53-enhancer-CAT, suggesting that the tat-mediated p53 suppression is not directly associated with p53-promoter. Finally, we have tested protein kinase activity in p53-tranfected Jurkat cells, which might phosphorylate HIV-1 tat, resulting in inhibition of tat function. Some of our data lead us to assume that the p53-mediated tat inhibition is likely to be associated with p53-associated, signaling-mediated phosphorylation of tat, resulting in the dysfunction of tat. This study is now under investigation.

• Journal of Mycology and Infection
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• v.23 no.4
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• pp.91-98
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• 2018

Background: Malassezia, a lipophilic yeast, is a causative agent for dandruff and seborrheic dermatitis. Many biological agents have been studied for anti-Malassezia effect but further studies are needed for their clinical application. Objective: The study was conducted to evaluate the inhibitory effect of different natural essential oils and a fruit extract on Malassezia species in an in vitro study and a clinical trial. Methods: The antifungal effects of natural essential oils and a fruit extract on Malassezia species (M. furfur and M. sympodialis) were evaluated by measuring the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) and using the disc diffusion method. Natural essential oils of citron seed, lavender, and rosemary and citrus junos fruit extract were used for the in vitro study. The clinical trial was conducted with a shampoo containing four ingredients. A total of 22 subjects used the shampoo every day for 4 weeks and were evaluated using clinical photography, trichoscopy, and sebumeter at baseline, 2 weeks, and 4 weeks after treatment. Results: Antifungal activity of agents was relatively lower in lavender and rosemary essential oils at MIC and MFC. Disc diffusion method revealed same results. In the clinical trial, the amount of sebum decreased statistically significantly and erythema, dandruff, and lesion extent also improved. Conclusion: The natural essential oils and fruit extract are effective for suppressing Malassezia activity, therefore these might be used as an alternative for treatment of dandruff and seborrheic dermatitis.

• Applied Biological Chemistry
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• v.48 no.1
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• pp.103-108
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• 2005

${\alpha}-Amylase$ inhibitor is used to control blood glucose level by inhibiting starch digestion in the small intestine and delaying the absorption of glucose. In this study, we investigated the effect of the ethanol extracts from more than 1400 species of plants against ${\alpha}-amylase$ with the aim of developing a new ${\alpha}-amylase$ inhibitor. In the results, Cornus walteri extracts showed the highest inhibition activity. The inhibitory effect of Cornus walteri extract on the carbohydrate hydrolysis enzymes has different sensitivities against ${\alpha}-amylase$ from salivary and pancreatin and against ${\alpha}-glucosidase$ from yeast and porcine small intestine. In the study of inhibition kinetics of ${\alpha}-amylase$ and ${\alpha}-glucosidase$, Cornus walteri extract showed competitive inhibition against salivary and pancreatin while showing the combination of uncompetitive and noncompetitive inhibition against ${\alpha}-glucosidase$. The Cornus walteri extract was stable at acidic and thermal conditions. As for the blood glucose and body weight levels of Cornus walteri extract, we confirmed anti-hyperglycemic and anti-obesity effects. Also, in the investigation of the mRNA lever, Cornus walteri extract upregulated the level of GLUT4 mRNA in the quadriceps muscle.