• 생약학회지
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• 제33권3호통권130호
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• pp.245-251
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• 2002

Flavonoid seems to have various biological effects. Quercetin is a kind of natural plant flavonoids and has multiple biological effects such as antioxidant, antimutagenic and anticarcinogenec agent. Melanogenesis is a physiological process resulting in the synthesis of melanin pigments, which play a crucial protective role against skin photocarcinogenesis. This present study was designed to investigate effect of quercetin on proliferation and melanogenesis in Melan-a melanocyte cells. After 48h treatment of cells with quercetin, the cells exhibited a dose-dependent inhibition in their proliferation without apoptosis. Therefore, thε growth retardation by the extract may be due to the cell arrest or cell differentiation. We also investigated the effect of quercetin on melanogenesis of this cells. Melan-a melanocyte cells were grown for 48h in the presence of $0.01-60\;{\mu}g/ml$ quercetin and the total melanin content and activity of tyrosinase were measured. Quercetin stimulated melanization of the cells in low concentrations $(0.01-1.0\;{\mu}g/ml)$, whereas it inhibited melanization in high concentrations $(5.0-30\;{\mu}g/ml)$. It was observed that quercetin differently regulates melanogenesis of Melan-a melanocyte cells dependent on Its concentrations.

• BMB Reports
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• 제38권2호
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• pp.121-127
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• 2005

Drosophila protects itself from infection by microbial organisms by means of its pivotal defense, the so-called innate immunity system. This is its sole defense as it lacks an adaptive immunity system such as is found in mammals. The strong conservation of innate immunity systems in organisms from Drosophila to mammals, and the ease with which Drosophila can be manipulated genetically, makes this fly a good model system for investigating the mechanisms of virulence of a number of medically important pathogens. Potentially damaging endogenous and/or exogenous challenges sensed by specific receptors initiate signals via the Toll and/or Imd signaling pathways. These in turn activate the transcription factors Dorsal, Dorsal-related immune factor (Dif) and Relish, culminating in transcription of genes involved in the production of antimicrobial peptides, melanization, phagocytosis, and the cytoskeletal rearrangement required for appropriate responses. Clarifying the regulatory interactions between the various pathways involved is very important for understanding the specificity and termination mechanism of the immune response.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 2003년도 제46회 춘계 학술연구 발표회
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• pp.49-49
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• 2003

DOPA decarboxylase (DDC), which converts DOPA to dopamine, is important for many biological event such as cuticular melanization, sclerotization and neurotransmission in insects. Recently, it has been also shown that DDC activity is correlated with pupal diapause in M. brassicae. The silkworm, Bombyx mori is a typical insect diapausing at early embryonic stage. (omitted)

• Molecules and Cells
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• 제43권2호
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• pp.114-120
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• 2020

Drosophila hematopoiesis is comparable to mammalian differentiation of myeloid lineages, and therefore, has been a useful model organism in illustrating the molecular and genetic basis for hematopoiesis. Multiple novel regulators and signals have been uncovered using the tools of Drosophila genetics. A Runt domain protein, lozenge, is one of the first players recognized and closely studied in the hematopoietic lineage specification. Here, we explore the role of lozenge in determination of prohemocytes into a special class of hemocyte, namely the crystal cell, and discuss molecules and signals controlling the lozenge function and its implication in immunity and stress response. Given the highly conserved nature of Runt domain in both invertebrates and vertebrates, studies in Drosophila will enlighten our perspectives on Runx-mediated development and pathologies.

• 대한화장품학회지
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• 제30권4호
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• pp.485-489
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• 2004

피부에서 melanin은 자외선 차단의 주요한 역할을 한다. Tyrosinase는 멜라닌 생합성과정에서 초기 단계에 관여하는 중요한 효소로서 이것의 조절을 통한 피부 멜라닌화 억제에 관해 많은 연구가 되어져왔다. 본 연구에서는 해녀콩 추출물에서 mushroom tyrosinase 활성억제, B16F10 melanoma 세포를 이용한 dopa oxidase 활성억제 및 멜라닌 합성 억제 효과를 확인하였다. Tyrosinase mRNA 발현에서의 억제 효과를 확인하기 위하여 RT-PCR을 이용하였으며, $CHCI_3$ 층에서 분리해낸 A 분획에서 tyrosinase mRNA 발현을 억제시킴을 확인하였다.

• 약학회지
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• 제46권2호
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• pp.137-142
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• 2002

Caesalpinia sappan L. has long been commonly used as emmenagogue, analgesic, and a cure for contusion and sprain as well as a remedy for thrombosis in the Oriental medicine. The main constituent of C. sappan is brazilein, which is an antioxidative substance that has a flavonoid structure. In this study, we examined the effect of butanol extract of C. sappan on proliferation and melanogenesis in B16/F10 melanoma cells. After 48h treatment of cells with various concentrations of butanol extract, the cells exhibited a dose-dependent inhibition in their proliferation without apotosis. Therefore, the growth retardation by the extract may be due to the cell arrest, not due to the cell death induced by cytotoxicity. We also estimated total melanin contents as a final product and activity of tyrosinase, a key enzyme, in melanogenesis of B16/F10 melanoma cells. Our result showed that the melanin contents and tyrosinase activity were decreased in butanol extract-treated cells in a dose dependent manner compared to control group. In conclusion, it was observed that butanol extract of C. sappan inhibited melanization of these cells and therefore butanol extract could be developed as skin whitening components of cosmetics.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1987년도 식물생명공학 심포지움 논문집 Proceedings of Symposia on Plant Biotechnology
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• pp.157-167
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• 1987

The have been many reports that phenoloxidase are correlated with development in many fungi. C. congregatus, one of nushroom-forming basidiomycetes, which requires light for its development also has phenoloxidases. In C. congragatus, there are two sets of membrane-associated phenoloxidase (PHO I and PHO II) which are differentiated by their isozyme patterns, and each enzyme set consists of two different subtrate specific enzyme protein; o-tolidine reacting enzyme, and DOPA reacting enzyme. PHO I which is localized by a protoplast-concanavalin A technique by using a new solidifying agent, Pluronic Polyol F 127, instead of agar appears in the vegetative hyphae, and PHO II appears at the early primordial stage on agar and at the sclerotial stage of liquid shake cultures. Inhibition of PHO I with the enzyme inhibitors inhibits mushroom formation as well as melanization of the vegetative hyphae at concentrations which do not inhibit the vegetative growth. PHO I deficient mutants do not form mushrooms or melanins, and the mutants show abnormal nuclear migration patterns. PHO II has roles; possibly cementing the adjacent hyphae during the actual three dimensonal structure formation, and melanizing mushrooms and sclerotia. The possible roles of PHO I in the light reception complex and in melanin formation, the function of malanin, and possible roles of postulated post translational modifying enzymes which regulate the phenoloxidases, nuclear migration pattern, and self-nonself recognition mechanism are discussed.

• 한국균학회지
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• 제22권1호
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• pp.46-49
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• 1994

C. congregatus를 산성 액체배지(pH4.2)에 배앙할 경우 세포막연관 laccase가 배양 초기에 대량 합성분비되었으며 분비된 효소의 작용에 의하여 melanin색소가 중성배지에 비하여 빨리 생성되었고 배양 24시간 후에 배지의 산도는 pH5.2로 증가되었다. 이 효소의 합성은 transcription inhibitor인 5-fluorouracil에 의하여 크게 억제되었다.

• Journal of Microbiology and Biotechnology
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• 제30권4호
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• pp.540-551
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• 2020

Sporotrichosis is a chronic and subacute mycosis causing epidemiological outbreaks involving sick cats and humans in southeastern Brazil. The systemic disease prevails in cats and in humans, with the symptoms restricted to the skin of immunocompetent individuals. Under these conditions, the prolonged treatment of animals and cases of recurrence justify the discovery of new treatments for sporotrichosis. This work addresses the antifungal activity of silver salts of Keggin-type heteropolyacid salts (Ag-HPA salts) such as Ag₃[PW₁₂O₄₀], Ag₆[SiW₁₀V₂O₄₀], Ag₄[SiW₁₂O₄₀] and Ag₃[PMo₁₂O₄₀] and interactions with the antifungal drugs itraconazole (ITC), terbinafine (TBF) and amphotericin B (AMB) on the yeast and mycelia forms of Sporothrix spp. Sporothrix spp. yeast cells were susceptible to Ag-HPA salts at minimum inhibitory concentration (MIC) values ranging from 8 to 128 ㎍/ml. Interactions between Ag₃[PW₁₂O₄₀] and Ag₃[PMo₁₂O₄₀] with itraconazole and amphotericin B resulted in higher antifungal activity with a reduction in growth and melanization. Treated cells showed changes in cell membrane integrity, vacuolization, cytoplasm disorder, and membrane detachment. Promising antifungal activity for treating sporotrichosis was observed for the Ag-HPA salts Ag₃[PMo₁₂O₄₀] and Ag₃[PW₁₂O₄₀], which have a low cost, high yield and activity at low concentrations. However, further evaluation of in vivo tests is still required.

• 대한화장품학회지
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• 제23권2호
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• pp.23-32
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• 1997

피부 내에서의 멜라닌 색소의 생성은 태양광에 존재하는 유해한 자외선으로부터 생체를 보호하는 중요한 방어 수단으로 여겨지고 있다. 타이로시네이즈라는 효소가 이러한 멜라닌의 합성 과정에 있어서 매우 중요한 역할을 수행한다. 이러한 이유로 피부의 색소생성을 조절하는 많은 연구의 대부분이 타이로시네이즈의 효소적 조절에 초점이 맞추어져 왔다. 본 연구자들은 전통 한약재인 반하의 물 추출물이 비록 타이로시제이즈에 대한 저해 작용은 없으나 배양된 B-16 마우스 흑색종 세포의 멜라닌 생성을 억제한다는 것을 발견하였다. 본 연구자들은 또한 반하 추출물이 배양된 세포의 타이로시네이즈 효소 활성을 낮춘다는 사실도 발견하였다. 이러한 반하 추출물의 작용 기작을 밝혀내기 위하여 반하 추출물이 B-16 마우스 흑색종 세포의 타이로시네이즈 mRNA양에 미치는 영향에 대하여 reverse transscription-polymerase chain reaction 기법을 이용, 연구를 수행 하였다. 연구 결과 반하 추출물은 타이로시네이즈 mRNA의 양을 용량 의존적인 경향으로 감소시킴이 밝혀졌다. 즉, 반하 추출물을 2$\mu\textrm{g}$/$m\ell$ 및 5$\mu\textrm{g}$/$m\ell$ 처리시 각각 20%와 44%의 mRNA 양의 감소가 관찰 되었다. 이러한 결과는 반하 추출물이 타이로시네이즈 mRNA의 전사 조절을 통하여 그 미백효과를 발휘한다는 것을 의미한다.