• Korean Journal of Plant Resources
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• v.29 no.2
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• pp.155-162
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• 2016

Melanin is produced by melanocytes of the melanoepidermic unit and other cell types. These cells secrete and distribute the melanin pigment, which provides protection from ultraviolet radiation. In this study, the inhibitory activity against tyrosinase and melanin biosynthesis in B16F10 melanoma cells and anti-wrinkling effects on human dermal fibroblasts of Dendrobium speciosum ethanol extract were investigated. The Dendrobium speciosum extract inhibited melanin biosynthesis and tyrosinase activity in a dose-dependent manner in comparison with an untreated control group. Treatment with the Dendrobium speciosum extract suppressed α-MSH-stimulated melanogenesis in B16F10 cells and the dendrite outgrowth of melanocyte/melanoma cells. The α-MSH-induced mRNA expression of tyrosinase-related protein-1 (TRP-1), tyrosinase-related protein-2 (TRP-2) and microphthalmia-associated transcription factor (MITF) was significantly attenuated in a concentration-dependent manner by Dendrobium speciosum treatment. In addition, Dendrobium speciosum treatment increased production of type I procollagen synthesis in human dermal fibroblasts. Dendrobium speciosum ethanol extract exhibited a potent inhibitory effect on melanin biosynthesis, tyrosinase activity and increased procollagen synthesis. These results indicate that Dendrobium speciosum shows promise as an ingredient in cosmeceutical products due to its whitening and anti-wrinkle effects.

• Journal of Photoscience
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• v.9 no.2
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• pp.209-212
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• 2002

Cutaneous hyperpigmentation is a well-known consequence of both acute and chronic X-irradiation, although the molecular mechanisms involved are not well understood. Recently, protein kinase C-$\beta$ (PKC-$\beta$) was shown to activate tyrosinase, a key and the rate-limiting enzyme in melanogenesis [1]. In this study, we have investigated its role in mediating ionizing radiation-induced pigmentation by exposing cultured human melanocytes to X-irradiation. Increased tyrosinase activity after the 4 Gys exposure was observed within 48 hrs and total melanin content doubled after 7 days. Interestingly, tyrosinase mRNA level was not affected by X-irradiation. However, there was a 2-3 fold increase in PKC-$\beta$ mRNA after 48 hours of irradiation, coinciding with the increase in tyrosinase activity. This induction was not due to non-specific heat generated during the irradiation because when melanocytes were incubated at 4$0^{\circ}C$, there was no induction of PKC-$\beta$ mRNA. Taken together, these data suggest that X-irradiation induces cutaneous hyperpigmentation, at least in part, by up-regulating the level of PKC-$\beta$.

• Archives of Pharmacal Research
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• v.22 no.3
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• pp.232-236
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• 1999

In this study, we present evidence that cotreatment of aloesin and arbutin inhibits tyrosinase activity in a synergistic manner by acting through a different action mechanism. Aloesin or arbutin similarly inhibited enzyme activity of human- and mushroom-tyrosinases with an IC50 value of 0.1 or 0.04 mM, respectively. Lineweaver-Burk plots of the enzyme kinetics data showed that aloesin inhibited tyrosinase activity noncompetitively with a Ki value of 5.3 mM, whereas arbutin did it competitively (Maeda, 1996). We then examined whether cotreatment of these agents inhibits the tyrosinase activity in a synergistic manner. The results showed that 0.01 mM aloesin in the presence of 0.03 mM arbutin inhibited activity of mushroom by 80% of the control value and the reverse was also true. The inhibitory effects were calculated to be synergistic according to the B rgi method. Taken together, we suggest that aloesin along with arbutin inhibits in synergy melanin production by combined mechanisms of noncompetitive and competitive inhibitions of tyrosinase activity.

• Proceedings of the SOHE Conference
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• 2004.12a
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• pp.88-88
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• 2004

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.20 no.3
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• pp.71-81
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• 2007

Objective : In this study, herbal medicine(GJE, Gardenia jasminoides Ellis; HCT, Houttuynia cordata Thunb.; CIL, Chrysanthemum indicum Linne; PMS,Paeonia moutan Sims, P. subfruticosa Makino; APL, Agrimonia pilosa Ledebour) were screened for their inhibitory activities against Tyrosinase and PMA plus A23187-induced $TNF-{\alpha}$, IL-6, IL-8 productions in HMC-1 cells to reveal their skin -whitening and anti-allergic effect. Method : To investigate Tyrosinase inhibition we treated Mushroom Tyrosinase(Fluka, 93898) $10{\mu}{\ell}$ and 7.5mM Tyrosine (Sigma, T3754) $20{\mu}{\ell}$ with 80% ethanol medicine extracts. Then we observed 96well micro plate extinction at 490nm. In the next experiment, to investigate Anti-allergic effect we blended cultured Human Mast Cells(HMC-1) with medicine extracts. We treated the blended solution with Phorbol 12-myristate 13-acetate(PMA) and A23187, then observed $TNF-{\alpha}$, IL-6, IL-8 by ELISA (enzyme-linked immunosorbent assay) at 450nm. Results : In inhibiting Tyrosinase the results are as follows. 1. We observed 22% inhibition of Mushroom Tyrosinase at $500{\mu}g/m{\ell}$ concentration of GJE extracts. 2. We also could observe that the decreased Mushroom Tyrosinase activities in HCT, CIL extracts. In inhibiing $TNF-{\alpha}$, IL-6, IL-8 productions in HMC-1 cells the results are as follows. 1. Of the extracts examined, HCT, PMS, APL extracts showed over 50% inhibitions of Cytokines at $200{\mu}g/m{\ell}$ concentration. 2. In particular, APL extracts showed the best inhibitory effect on Cytokine productions in a dose-dependent manner. Conclusion : These results suggest that GJE extracts contributes to the anti melanin activities and represent a potential source of whitening agent. Thus these herbal medicines suggest novel drugs on anti-allergic effects.

• Journal of Life Science
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• v.24 no.3
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• pp.284-289
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• 2014

Tyrosinase is a rate-limiting enzyme that controls the production of melanin. The effect of bamboo (Phyllostachys bambusoides) on tyrosinase activity and melanin synthesis has not been studied. We analyzed the effects of leaf and inner film fractions of bamboo extracts on the inhibition of tyrosinase activity and on melanin production. At a concentration of 5 mg/ml, the extracts of bamboo down-regulated the production of melanocytes. In addition, the extracts of bamboo reduced tyrosinase activity and the melanin content in vitro. Our results suggest that bamboo extract may constrain melanin synthesis by inhibition of the activity and expression of tyrosinase.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.3
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• pp.830-836
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• 2004

The unique biochemical pathways in melanocytes responsible for melanogenesis provide us with a rational mechanism-based means for developing both pharmacological regulators of pigmentation and cytotoxic chemotherapeutic drugs for melanoma, Myricetin is a polyphenolic antioxidant and a component from Biotae Semen, Biotae orientalis Folium. Therefore, the present study was conducted to evaluate the effects of myricetin on the melanogenesis in human melanoma (HM₃KO) cells. The cells were treated for 5 days with myricetin at several concentrations (10 - 100 μg/ml). Treatment with myricetin dose-dependently suppressed cell growth in HM₃KO cells, But melanin formation was markedly increased by myricetin as a dose dependent manner. Myricetin did not affect to tyrosinase activity, which is a key enzyme for melanogenesis, but significantly increased the level of tyrosinase protein expression, These results suggest that myricetin stimulate melanin synthesis of human melanoma cells through the modification of tyrosinase protein expression.

• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.182-186
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• 2012

human tyrosinase (hTyr) catalyzes first and the rate limiting step in the synthesis of polymerized pigment, melanin which determines skin, hair and eye colors. Mutation of hTyr often brings about decrease of melanin production and further albinism. Meanwhile, a number of cosmetic companies providing skincare products for woman in Asia-Pacific region have tried to develop inhibitors to bright skin color for several decades. In this study, we built a 3D structure by comparative modeling technique based on the crystal structure of tyrosinase from bacillus megaterium as a template to serve structural information of hTyr. According to our model and sequence analysis of type 3 copper protein family proteins, two copper atoms of active site located deep inside are coordinated with six strictly conserved histidine residues coming from four-helix-bundle. Cavity which accommodates substrates was like funnel shape of which entrance was wide and expose to solvent. In addition, protein-substrate and protein-inhibitor complex were modeled with the guide of van der waals surface generated by in house software. Our model suggested that only phenol group or its analogs can fill the binding site near nuclear copper center because inside of binding site has narrow shape relatively. In conclusion, the results of this study may provide helpful information for designing and screening new anti-melanogensis agents.

• Herbal Formula Science
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• v.31 no.3
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• pp.183-191
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• 2023

Objective : UVB damages skin health by causing skin redness and intense inflammation, sunburn, and skin cancer. Paeoniae Radix Alba has been used to relieve gynecological symptoms, muscle spasms, and skin ailments. This study was conducted to confirm whether it has a protective effect against UVB photodamage. Methods : Ethanol extract of Paeoniae Radix Alba (PRA) was prepared by extracting 100 g Paeoniae Radix Alba in 1 L of ethanol for 48 h. Apoptosis was monitored by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and expression levels of apoptosis indicator proteins, and tyrosinase activity was measured with a colorimetric commercial kit. Results : In human keratinocyte HaCaT cells, PRA reduced UVB-induced cell death through apoptosis by inhibiting PARP cleavage and caspase-3 and -9. UVB-induced increase in cellular reactive oxygen species (ROS) was suppressed by PRA pretreatment. PRA also showed dose-dependent ABTS and DPPH radical scavenging activities. Furthermore, the inhibitory effect of tyrosinase activity by PRA was confirmed. Conclusion : These results demonstrated the protective role of PRA in UVB photodamage of human keratinocytes, mainly due to its antioxidant and antiapoptotic properties. We also suggest that PRA can be considered as an effective natural agent to prevent skin photodamage.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.1
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• pp.33-38
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• 2004

Melanin pigmentation in human skin is a major defense mechanism against ultraviolet light of the sun, but abnormal pigmentation such as freckles, liver spot could be a serious aesthetic problem. Nearly all studies are mainly concentrated on searching for the materials that have inhibitory activities on tyrosinase. In this work, to isolate phenolic compounds from Gastrodia elata, we purified the extract through solvent fractionation, column chromatography, and recrystallization. They were identified as 4-hydroxybenzyl alcohol 1, bis(4-hydroxyphenyl)methane 2, gastrodin (4-${\beta}$-D-glucopyranosyloxybenzyl alcohol) 3 on the base of spectroscopic evidences. In order to investigate their depigmentation effect, inhibitory activity against mushroom tyrosinase and inhibitory activity of melanin synthesis in B16 melanoma cells were evaluated in vitro. We have found that 4-hydroxybenzyl alcohol 1 and gastrodin (4- ${\beta}$-D-glucopyranosyloxybenzyl alcohol) 3 have no tyrosinase inhibitory activity, but inhibit the melanin synthesis in B16 melanoma cells. Tyrosinase inhibitory activities of bis(4-hydroxyphenyl)methane 2 (IC$\_$50/ = 400 $\mu\textrm{g}$/mL) and butanol fraction (IC$\_$50/ = 46 $\mu\textrm{g}$/mL) were lower/higher than that of arbutin (IC$\_$50/ = 114 $\mu\textrm{g}$/mL), but inhibitory activities of melanin synthesis in B16 melanoma cells were much higher than that of arbutin. Especially, tyrosinase inhibitory activities of isolated phenolic fraction (IC$\_$50/ = 2.37 $\mu\textrm{g}$/mL) from butanol fraction was very higher than that of arbutin (IC$\_$50/ = 114 $\mu\textrm{g}$/mL). Therefore, these results suggest that isolated phenolic compounds from Gastrodia elata have inhibitory activity against mushroom tyrosinase and inhibitory activity of melanin synthesis in 816 melanoma cells in vitro.