• 제목/요약/키워드: ${\alpha}$-MSH

검색결과 151건 처리시간 0.023초

Regulation of Proopiomelanocortin and Melanocortin 1 Receptor by UVB: Inhibitory Effect of Antioxidants

  • Funasaka, Yoko
    • Journal of Photoscience
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    • 제9권2호
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    • pp.201-204
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    • 2002
  • Epidermal cells produce a panel of antioxidants as well as cytokines after UVB irradiation, which counteract reactive oxygen species, however, how these antioxidants might regulate melanogenesis is unclear. An important constituent of the cellular antioxidant buffering system which controls the redox state of proteins is thioredoxin (TRX), a 13-kD protein that catalyzes thiol-disulfide exchange reactions, regulates activation of transcription factors, and possesses several other biological functions similar to cytokines. TRX suppressed the UVB-induced production and secretion of $\alpha$-melanocyte stimulating hormone ($\alpha$-MSH) and of adrenocorticotropic hormone (ACTH), and also suppressed proopiomelanocortin (POMC) mRNA expression by normal human keratinocyte (KC)s. Further, L-cysteine, N-acetyl-cysteine, $\alpha$-tocopheryl ferulate showed suppressive effect on UVB-induced POMC mRNA expression. However, TRX released from UVB-irradiated KCs stimulated melanogenesis by up-regulating MSH receptor expression and its binding activity in melanocyte (MC)s. UVB-induced KC derived cytokines such as IL1, IL6, and ET1 upregulated MSH-receptor binding ability as well as MCl-R mRNA expression in cultured normal human MCs. MCl-R has a tendency to be upregulated by UVB-induced KC-derived cytokines as well as by direct UVB irradiation. These results suggest that antioxidants such as TRX suppresses UVB induction of POMC, but in the case of MCl-R, this gene can be mainly in the trend of upregulation by UVB-induced KC-derived factors including TRX.

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The effects of green tea (Camellia sinensis) flower extract on melanin synthesis in B16-F10 melanoma cells

  • Dissanayake, Chanuri-Yashara;Moon, Hae-Hee;Yang, Kyeong-Mi;Lee, Younjae;Han, Chang-Hoon
    • 대한수의학회지
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    • 제58권2호
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    • pp.65-72
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    • 2018
  • The present study observed the effects of a green tea (Camellia sinensis) flower extract (GTFE) on melanin synthesis in B16-F10 melanoma cells. GTFE exhibited antioxidant activity on 2,2-diphenyl-1-picrylhydrazyl and inhibited mushroom tyrosinase activity in a dose-dependent manner. Furthermore, GTFE significantly diminished ${\alpha}-melanocyte$ stimulating hormone (${\alpha}-MSH$) stimulated cellular melanin content and tyrosinase activity throughout the concentration range evaluated. Based on RNA sequencing analysis, differential gene expression patterns observed in ${\alpha}-MSH$ stimulated B16-F10 melanoma cells were normalized by the addition of GTFE. In particular, the expression levels of melanoregulin and tyrosinase genes which are key regulating genes in melanin synthesis were up-regulated by 3.5 and 3 fold respectively by ${\alpha}-MSH$, and were normalized to control levels by the addition of GTFE. The results suggest that GTFE inhibits melanin synthesis in ${\alpha}-MSH$ stimulated B16-F10 melanoma cells by normalizing expression of genes that are essential for melanin synthesis. Overall, the results suggest that GTFE could be applied in the development of a whitening agent for the treatment of dermal hyperpigmentation.

B16 멜라닌 세포에서 해양소재 추출물의 멜라닌 생성 저해 효과 (Inhibitory Effects of Marine Natural Products on Melanogenesis in B16 Melanoma Cells)

  • 이찬;장정희;안은미;박찬익
    • 대한본초학회지
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    • 제27권4호
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    • pp.73-80
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    • 2012
  • Objectives : Under normal condition melanin protects the skin from extracellular stimuli including ultraviolet (UV)-induced oxidative skin damages, but excess production and accumulation of melanin can induce hyperpigmentation causing esthetic problems. Therefore, in this study we tried to search for natural skin whitening materials from marine natural resources. Methods : Water and ethanol extracts of marine natural resources were prepared from Porphyra thalli (PT), Laminariae thallus (LT), Ostreae concha (OC), Sargassum thallus (ST), Undaria thallus (UT), Codium thalli (CT), Enteromorpha thalli (ET), Syngnathoides biaculeatus (SB), and Hippocampus coronatus (Hc). Their effects against UVB and ${\alpha}$-melanocyte stimulating hormone (${\alpha}$-MSH)-induced melanogenesis were investigated based on melanin formation in B16 mouse melanoma cells. The mRNA and protein expression of enzymes involved in the melanogenic process were further examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. Results : Water extract of Ostreae concha (OCW/E) effectively inhibited UVB and ${\alpha}$-MSH-induced melanin production in B16 melanocytes, which seemed to be mediated by inhibition of mRNA expression of tyrosinase and tyrosinase-related protein 1 (TRP-1). In another experiment, ethanol extracts from Porphyra thalli (PTE/E), Laminariae thallus (LTE/E), Sargassum thallus (STE/E), Undaria thallus (UTE/E), Codium thalli (CTE/E), Syngnathoides biaculeatus (SBE/E), and Hippocampus coronatus (HcE/E) significantly suppressed UVB and ${\alpha}$-MSH-induced melanin formation. Furthermore, ethylacetate fraction isolated form LTE/E (LTE/EEt) decreased UVB and ${\alpha}$-MSH-elevated extracellular melanin levels via inhibition of tyrosinase protein expression. Conclutions : These results suggest that marine natural resources such as Porphyra thalli, Laminariae thallus, Ostreae concha, Sargassum thallus, Undaria thallus, Codium thalli, Syngnathoides biaculeatus and Hippocampus coronatus have anti-melanogenic effects, thereby exhibiting high potentials to be utilized as one of the ingredients for the development of new whitening functional cosmetics.

Development of Melanotropin Antagonists: Investigating Potent and Specific Ligands for New Receptors

  • Lim, Sejin
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1996년도 제4회 추계심포지움
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    • pp.153-159
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    • 1996
  • ${\alpha}$-Melanotropin (Ac-Ser-Tyr- Ser-Met-Glu$\^$5/-His-Phe-Arg-Trp-Gly$\^$10/-Lys-Pro-Val-NH$_2$) is one of the first peptide hormones to be isolated and have its structure determined. It was early recognized to have essentially the same N-terminal tridecapeptide sequence as adrenocorticotropic hormone (ACTH) except that the N-terminal was acetylated in the case of ${\alpha}$-MSH but not in the case of ACTH, indicating that their biosyntheses were different (Figure 1). Subsequently it was discovered that ${\alpha}$-MSH and ACTH were derived from the same gene, currently referred to as proopiomelanocortin (POMC). Its original bioactivity was pigmentation, but it also was recognized that it may have activity in the central nervous system, though the precise nature of these central activities have been controversial. The recent cloning and expression of five melanocortin receptors, with the MC3 and MC4 receptors found primarily in the brain and the MC5 receptor (MC5-R) found throughout the body, has provided new impetus to understand the structure-activity relationships of ${\alpha}$-MSH at these receptors. The effects of ${\alpha}$-MSH on pigmentation are mediated by the MC1-R expressed specifically on the surface of melanocytes. Similarly the MC2-R is involved in the regulation of adrenal steroidogenesis by ACTH. However, given the complexity of expression of the MC3, MC4, and MC5 receptors, it has not been possible to identify any simple correlations between these receptors and the reported biological activities of the melanocortin peptides. Consequently, potent and receptor specific agonists and especially antagonists would be extremely valuable tools for the determination of the physiological roles of the MC3, MC4, and MC5 receptors. Though the extensive structure-activity relationships have provided much information on agonist activity related to pigmentary effects, only recently has it been possible to begin to systematically develop potent and selective antagonists.

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백출의 에탄올 추출물에 의한 Melanin 생성억제 효과 (Inhibitory Effects of Ethanol Extract of Atractylodis Rhizoma alba on Melanin Biosynthesis)

  • 천현자;최은영;윤성찬;남항우;백승화
    • 약학회지
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    • 제45권3호
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    • pp.269-275
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    • 2001
  • The inhibitory effect of extract of Atractylodis Rhizoma alba on melanin biogenesis was studied by using B16/F10 melanoma in culture. Atractylodis Rhizoma alba significantly inhibited tyrosinase activity, and melanin contents with or without $\alpha$-MSH and forskolin in vitro. Melanin contents and tyro-sinase activity have decreased in a dose-dependent manner. These results show that extract of Atractylodis Rhizoma alba could be developed as skin whitening components of cosmetics.

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Suppressed DNA Repair Mechanisms in Rheumatoid Arthritis

  • Lee, Sang-Heon;Firestein, Gary S
    • IMMUNE NETWORK
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    • 제2권4호
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    • pp.208-216
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    • 2002
  • Background: Reactive oxygen and nitrogen are produced by rheumatoid arthritis (RA) synovial tissue and can induce mutations in key genes. Normally, this process is prevented by a DNA mismatch repair (MMR) system that maintains sequence fidelity. Key members of the MMR system include MutS${\alpha}$ (comprised of hMSH2 and hMSH6), which can sense and repair single base mismatches and 8-oxoguanine, and MutS${\beta}$ (comprised of hMSH2 and hMSH3), which repairs longer insertion/deletion loops. Methods: To provide further evidence of DNA damage, we analyzed synovial tissues for microsatellite instability (MSI). MSI was examined by PCR on genomic DNA of paired synovial tissue and peripheral blood cells (PBC) of RA patients using specific primer sequences for 5 key microsatellites. Results: Surprisingly, abundant MSI was observed in RA synovium compared with osteoarthritis (OA) tissue. Western blot analysis of the same tissues for the expression of MMR proteins demonstrated decreased hMSH6 and increased hMSH3 in RA synovium. To evaluate potential mechanisms of MMR regulation in arthritis, fibroblast-like synoviocytes (FLS) were isolated from synovial tissues and incubated with the nitric oxide donor S-nitroso-N-acetylpenicillamine (SNAP). Western blot analysis demonstrated constitutive expression of hMSH2, 3 and 6 in RA and OA FLS. When FLS were cultured with SNAP, the RA synovial pattern of MMR expression was reproduced (high hMSH3, low hMSH6). Conclusion: Therefore, oxidative stress can relax the DNA MMR system in RA by suppressing hMSH6. Decreased hMSH6 can subsequently interfere with repair of single base mutations, which is the type observed in RA. We propose that oxidative stress not only creates DNA adducts that are potentially mutagenic, but also suppresses the mechanisms that limit the DNA damage.

백합뿌리 추출물의 멜라닌 생성 억제효과 (Hypopigmenting Effects of Extracts from Bulbs of Lilium Oriental Hybrid 'Siberia' in Murine B16/F10 Melanoma Cells)

  • 윤훈석;양경월;김정은;김정미;이남호;현창구
    • 한국식품영양과학회지
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    • 제43권5호
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    • pp.705-711
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    • 2014
  • 피부미백 소재를 개발하기 위해 멜라닌 함량, 세포내 tyrosinase 활성의 측정 및 Western blotting 실험이 수행되었다. 백합(Lilium Oriental Hybrid 'Siberia') 뿌리의 80% 에탄올 추출물로부터 얻은 에틸아세테이트 분획물(R-EA)은 ${\alpha}$-melanocyte stimulating hormone(${\alpha}$-MSH)에 의해 멜라닌 생성이 유도된 B16/F10 흑색종 세포에서 농도 의존적으로 멜라닌 생성을 저해하였다. 정확하게 세포내 tyrosinase 활성과 멜라닌 함량은 에틸아세데이트 분획물 $100{\mu}g/mL$ 처리 시 ${\alpha}$-MSH 단독 처리군에 비해 각각 45%와 74%의 저해율을 보였다. ${\alpha}$-MSH에 의해 멜라닌 생성이 유도된 B16/F10 흑색종 세포에서 단백질 발현양상을 살펴본 결과 TRP-1이 가장 많이 억제된 양상을 확인할 수 있었고 이 결과는 세포내 tyrosinase 활성저해보다 멜라닌 생성저해가 더 많이 일어난 것과 일맥상통하는 것이다. 이를 종합해 볼 때 p-coumaric acid와 resveratrol 함량이 백합뿌리의 에탄올 추출물에 비해 많이 함유된 에틸아세테이트 분획물은 멜라닌 생성 유도물질에 의해 촉진된 ERK의 활성화를 억제하는 피부미백 소재로서 그 가치가 입증된다고 사료된다.

B16 Melanoma 세포에서 Arctigenin이 Tyrosinase 활성과 Melanin 생성에 미치는 영향 (Effect of Arctigenin on Tyrosinase Activity and Melanin Production in B16 Melanoma Cells)

  • 이동자;심상수
    • 약학회지
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    • 제56권6호
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    • pp.395-400
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    • 2012
  • To investigate the possibility of development as a whitening agent using arctigenin, we measured DPPH assay, NBT/XO assay, intracellular ROS scavenging assay, tyrosinase assay and MSH-induced melanin production in B16 melanoma cells. Arctigenin dose-dependently had anti-oxidant activity in DPPH, NBT/XO and intracellular ROS assay. Although arctigenin did not inhibit purified tyrosinase activity, it dose-dependently inhibited tyrosinase activity and melanin production in B16 melanoma cells stimulated by $1{\mu}M$ ${\alpha}$-MSH. In particular, arctigenin at a concentration $100{\mu}M$ inhibited ${\alpha}$-MSH-stimulated tyrosinase activity and melanin production by $50.9{\pm}2.9%$ and $69.0{\pm}6.5%$ respectively. And typical tyrosinase inhibitor, arbutin, inhibited $57.7{\pm}2.9%$ and $65.1{\pm}5.0%$ respectively. Such an similar inhibitory effect of arctigenin and arbutin in B16 melanoma cells may be due to the inhibition of MSH signal pathway rather than the direct inhibition of tyrosinase. Therefore, these results suggest that arctigenin may be useful for the development as whitening agents.

Comparative Depigmentation Effects of Resveratrol and Its Two Methyl Analogues in α-Melanocyte Stimulating Hormone-Triggered B16/F10 Murine Melanoma Cells

  • Yoon, Hoon-Seok;Hyun, Chang-Gu;Lee, Nam-Ho;Park, Sung-Soo;Shin, Dong-Bum
    • Preventive Nutrition and Food Science
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    • 제21권2호
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    • pp.155-159
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    • 2016
  • Previous research showed that resveratrol (trans-3,4',5-trihydroxystilbene) and pinostilbene (trans-3-methoxy-4',5-dihydroxystilbene) were able to inhibit tyrosinase directly; however, anti-melanogenic effects of pterostilbene (trans-3,5-dimethoxy-4'-hydroxystilbene) and resveratrol trimethyl ether (RTE) have not been compared. To investigate the hypopigmentation effects of pterostilbene and RTE, melanin contents and intracellular tyrosinase activity were determined by western blot analysis. Firstly, pterostilbene showed the inhibitory effects on ${\alpha}$-melanocyte stimulating hormone (MSH)-induced melanin synthesis stronger than RTE, resveratrol, and arbutin. Pterostilbene inhibited melanin biosynthesis in a dose-dependent manner in ${\alpha}$-MSH-stimulated B16/F10 murine melanoma cells. Specifically, melanin content and intracellular tyrosinase activity were inhibited by 63% and 58%, respectively, in response to treatment with $10{\mu}m$ of pterostilbene. The results of western blot analysis indicated that pterostilbene induced downregulation of tyrosinase protein expression and suppression of ${\alpha}$-MSH-stimulated melan-A protein expression stronger than RTE or resveratrol. Based on these results, our study suggests that pterostilbene can induce hypopigmentation effects more effectively than resveratrol and RTE, and it functions via downregulation of protein expression associated with hyperpigmentation in ${\alpha}$-MSH-triggered B16/F10 murine melanoma cells.

A mixture of seaweed extracts and glycosaminoglycans from sea squirts inhibits α-MSH-induced melanogenesis in B16F10 melanoma cells

  • Wang, Lei;Cui, Yong Ri;Yang, Hye-Won;Lee, Hyo Geun;Ko, Ju-Young;Jeon, You-Jin
    • Fisheries and Aquatic Sciences
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    • 제22권5호
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    • pp.11.1-11.8
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    • 2019
  • Background: In the present study, the skin-whitening effects of a marine-sourced mixture that includes a fucoidanrich extract of Undaria pinnatifida (UPEF), a phlorotannin-rich extract of Ecklonia cava (ECE), and glycosaminoglycans (GAGs) from sea squirt skin were investigated. Methods: The whitening effects of the mixture and its components were evaluated by measuring the inhibition of mushroom tyrosinase and melanin synthesis in alpha-melanocyte-stimulating hormone (${\alpha}$-MSH)-stimulated B16F10 melanoma cells. Results: Each component alone markedly inhibited mushroom tyrosinase in a dose-dependent manner, and in ${\alpha}$-MSH-stimulated B16F10 cells, they inhibited melanin synthesis and were cytotoxic. However, the whitening effects of UPEF, ECE, and GAGs in combination were greater than those of each component alone. A mixture in the ratio of 4:5:1 (UEG-451) showed the strongest activity without cytotoxicity. Further study suggested that UEG-451 inhibits ${\alpha}$-MSH-stimulated melanogenesis in B16F10 cells by downregulating tyrosinase and tyrosinase-related proteins, such as TRP-1 and TRP-2, via the inhibition of MITF expression. Conclusions: These results suggest that mixing the different components at optimum ratios might be an effective way to improve their bioactivities and reduce toxicity and that UEG-451 possesses strong whitening effects that could be used in the cosmetic industry.