• Biomolecules & Therapeutics
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• v.20 no.3
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• pp.340-345
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• 2012

Sarsasapogenin (SAR) is a steroidal sapogenin that is used as starting material for the industrial synthesis of steroids. It has various pharmacological benefits, such as antitumor and antidepressant activities. Since its effect on melanin biosynthesis has not been reported, we used murine melanocyte melan-a cells to investigate whether SAR influences melanogenesis. In this study, SAR significantly increased the melanin content of the melan-a cells from 1 to 10 ${\mu}M$. Based on an enzymatic activity assay using melan-a cell lysate, SAR had no effect on tyrosinase and DOPAchrome tautomerase activities. It also did not affect the protein expression of tyrosinase-related protein 1 and DOPAchrome tautomerase. However, protein levels of tyrosinase and microphthalmia-associated transcription factor were strongly stimulated by treatment with SAR. Therefore, our reports suggest that SAR treatment may induce melanogenesis through the stimulation of tyrosinase and microphthalmia-associated transcription factor expression in melan-a cells.

• Korean Journal of Pharmacognosy
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• v.33 no.3 s.130
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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.

• Environmental Analysis Health and Toxicology
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• v.25 no.1
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• pp.69-77
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• 2010

The purpose of this study is to evaluate the effectiveness of Scirpi rhizoma ethanol extract (SREE) on skin whitening using in vitro test. In the antioxidative activities, it was found that SREE contains 38.9 mg/g of polyphenol and 74.5 mg/g of flavonoid in total. In the electron donating ability, SREE showed a dose-dependent response, showing a high antioxidative capacity of 86.1% at 1000 ppm. It was found that the maximum permissible level of SREE to Melan-a cells was over 200 ppm, showing a quite low toxicity of SREE against Melan-a cells. Both in the inhibitory measurement for tyrosinase activity and melanogenesis using Melan-a cells, SREE presented a dose-dependent response with excellent efficacy.

• BMB Reports
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• v.36 no.2
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• pp.173-178
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• 2003

Malignant melanoma is one of the most rapidly increasing cancer types, and patients with metastatic disease have a very poor prognosis. Detection of metastatic melanoma cells in circulation may aid the clinician in assessing tumor progression, metastatic potential, and response to therapy. Tyrosinase is a key enzyme in melanine biosynthesis. The gene is actively expressed in melanocytes and melanoma cells. Melan A is a differentiation antigen that is expressed in melanocytes. The presence of these molecules in blood is considered a marker for circulating melanoma cells. In this study, we analyzed the usefulness of this marker combination I evaluating the response to therapy in the blood of 30 patients with malignant melanoma. Circulating cells were detected by a reverse-transcriptase-polymerase-chain reaction. The tyrosinase expression was observed in 9 (30%) patients and Melan A in 19 (63.3%) patients before therapy. Following treatment, the tyrosinase mRNA was detected in only one patient, while Melan A transcripts were still present in 14 patients. We suggest that this molecular assay can identify circulating melanoma cells that express melanoma-associated antigens and may provide an early indication of therapy effectiveness.

• Korean Journal of Pharmacognosy
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• v.33 no.2 s.129
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• pp.130-136
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• 2002

Melanogenesis is a physiological process resulting in the synthesis of melanin pigments, which play a crucial protective role against skin photocarcinogenesis. The heart wood of Caesalpinia sappan L.(C. sappan) has long been commonly used in Oriental folk medicines to promote blood circulation, and as an emmenagogue, analgesic or anti-inflammatory agent as well as a remedy for thrombosis. From the heartwood, many constituents have been purified and among them, brazilin and hematoxylin are two of the most abundant. This present study was designed to investigate the inhibitory effect of butanol extract from C. sappan on proliferation and melanogenesis in Melan-a cells. After 48 h treatment of these cells with various concentrations of butanol extract, the cells showed a dose-dependent inhibition in their proliferation without apoptotic cell death. Therefore, the growth retardation by the extract may be due to the cell arrest or cell differentiation. We also estimated total melanin content as a final product and activity of tyrosinase, a key enzyme, of melanogenesis in Melan-a cells. The melanin content and tyrosinase activity were deσeased in extract-treated cells in a dose dependent manner compared to control group. The butanol extract also resulted in a decrease of melanin content in ${\alpha}-melanocyte-stimulating$ hormone (MSH)-induced melanogenesis, indicating that butanol extract of C. sappan could be developed as skin whitening components of cosmetics.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.612-615
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• 2009

A 10-year-old intact male mixed breed dog was presented with a three-month history of massive oral mass. Physical examination revealed extending mass from the right upper gingiva. No metastasis was found at the time of presentation. Histopathologic examination of biopsied tissue from the oral mass was consistent with a neuroendocrine tumor with generalized epithelioid cells and few spindle cells. There were highly mitoses and no visible melanin granules with H&E staining. Immunohistochemical staining for Melan A was performed on section of tumor and was strongly positive. Diagnosis was made as amelanotic malignant melanoma based on histopathology with Melan A immunohistochemistry. This case study indicates that the Melan A immunohistochemical staining may be valuable to diagnose amelanotic malignant melanoma in dogs.

• Natural Product Sciences
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• v.22 no.3
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• pp.168-174
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• 2016

Anti-melanogenic effects of amaranth (AT), one of the key source of squalene, were investigated in melanocytes. Amaranth seed powder was extracted with water and melan-a cells were treated with various concentrations of AT. By using HPLC, content of myo-inositol, one of potential active components, was measured in the crude extract of AT.AT reduced the melanin content in melan-a melanocytes and down-regulated melanogenic enzyme activity such as tyrosinase, TRP-1 and TRP-2. By regulating melanogenic enzyme activity, AT may be a potential natural source for whitening agent. Myo-inositol was detected in AT by HPLC and may be one of the active compounds from AT involved in the regulation of anti-melanogenesis. In this study, we demonstrated that AT has anti-melanogenesis properties. This new function of amaranth may be useful in the development of new skin-whitening products and its value as food.

• Korean Journal of Medicinal Crop Science
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• v.17 no.4
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• pp.293-300
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• 2009

This study was carried out to investigate the effect of Cinnamomum camphora on melanogenesis. The MeOH extract of Cinnamomum camphora inhibited mushroom tyrosinase activity in dose-dependent manner. Moreover, it significantly suppressed the melanin production in melan-a cells at the concentration of $100{\mu}/m{\ell}$. The MeOH extract was partitioned with ethyl acetate, n-butanol and water. Among them, the BuOH soluble fraction exhibited significant inhibitory effect on mushroom tyrosinase. In addition, the BuOH soluble fraction reduced the melanin production in melan-a cells. But, the BuOH soluble fraction had less inhibition effects on melan-a cell originated tyrosinase. So, it was performed western blotting for melanogenic proteins (tyrosinase, tyrosinase-related protein (TRP-2)) using melan-a cells. The BuOH soluble fraction inhibited the protein expression of tyrosinase at the concentration of $100{\mu}/m{\ell}$. The results suggested that the BuOH soluble fraction of C. camphora might be a potent inhibitor of melanin biosynthesis in melan-a cells.

• Natural Product Sciences
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• v.17 no.1
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• pp.26-32
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• 2011

Novel tyrosinase inhibitors are important for pigmentation in the skin. Following extraction of tyrosinase inhibitors from edible vegetables or fruits, we found that the Prunus persica flesh extract (PPFE) exhibited potential inhibitory activity for melanogenesis. PPFE showed tyrosinase inhibitory activity in an enzymatic assay and PPFE also significantly inhibited the melanin formation in cultured mouse melan-a cells. Moreover, real-time RT-PCR analysis revealed that the inhibition of melanin production by PPFE was closely related to marked suppression of mRNA expression of tyrosinase and tyrosinase-related protein-1 and -2 (TRP-1 and TRP-2) in melan-a cells. Further investigation found that the modulation of tyrosinase expression by PPFE was associated with the transcriptional regulation of the microphthalmia-associated transcription factor (MITF). PPFE inhibited the promoter activity of MITF and suppressed MITF mRNA expression in melan-a cells. These results indicate that PPFE down-regulates melanogenesis-associated gene expression through MITF-mediated transcriptional regulation and these events might be related to the hypopigmentary effects of PPFE.

• Korean Journal of Veterinary Service
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• v.34 no.3
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• pp.273-278
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• 2011

Sertoli cell tumor (SCT) of the testicle arises from the supporting cells within the seminiferous tubules. SCT is common in dogs, especially in cryptorchid testicles, but also has been reported in the stallion, ram, cat, and bull. Sertoli cell tumor sample was collected from 7-years male german shepherd. In this study, SCT arose from one testicle. Sample size is approximately 1.7 cm in diameter and it has a round form. In the microscopic, cells within the tumor variably resemble Sertoli cells (SCs) that normally populate the seminiferous tubules and interstitial area. There is abundant stroma of dense, mature fibrous connective tissue in SCT. In the immunohistochemical staining, cytokeratin AE1/AE3 was not expressed in the control and SCT. S-100 protein was expressed by SCs, germ cells and fibrous connective tissue of SCT. Melan A was expressed by leydig cells (LCs) of SCT. A study by using S-100 and melan A in canine SCT was almost never carried out. S-100 and melans A is considered to suggest for diagnosis and pathogenesis of canine SCTs. Inhibin-alpha and Vimentin were well known as the marekers of SCTs. Also, they were expressed by Sertoli cells and LSs of SCT in this study.