• Bulletin of the Korean Chemical Society
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• v.30 no.2
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• pp.475-478
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• 2009

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.2051-2053
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• 2010

• Bulletin of the Korean Chemical Society
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• v.29 no.8
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• pp.1569-1571
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• 2008

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.3
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• pp.265-271
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• 2017

In this study, anti-oxidant, whitening and anti-aging effects were investigated the possibility of fermented black tea yeast as a functional cosmetic material. The results of Aureobasidium pullulans (A. pullulans) ferment of black tea (AFBT) were compared with black tea (BT) and A. pullulans ferment (AF). The antioxidant activity of the AFBT product showed DPPH radical scavenging ability higher than that of AF. In the intracellular ROS experiments induced by hydrogen peroxide, the AFBT showed significant decreased activity. In addition, AFBT showed tyrosinase inhibitory activity and inhibited the formation of melanin using Melan-a and B16F10 cells. Through suppression of MMP-1 expression, the AFBT showed higher anti-wrinkle activity than BT and AF. From the results of this study, it was confirmed that AFBT showed antioxidant activity and was developed as a functional cosmetic material based on whitening and anti-wrinkle efficacies.

• Biomolecules & Therapeutics
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• v.22 no.5
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• pp.431-437
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• 2014

Synthetic compounds that are used in the clinic to regulate skin hyperpigmentation, such as arbutin, hydroquinone, and kojic acid, are only moderately effective. But, their use is limited by side effects. As part of an effort to overcome the limitations, we developed resveratrol-enriched rice (RR) using genetic engineering technique. Each of resveratrol and rice has been reported to produce anti-melanogenic effects. Therefore, we hypothesized that RR would show more anti-melanogenic effects than those of resveratrol or rice alone. Anti-melanogenic effect of RR was done by using melan-a mouse melanocytes. The depigmenting efficacy was then observed following topical application of the RR to UVB-stimulated hyperpigmented dorsal skin of guinea pigs. Treatment with RR extract resulted a $21.4{\pm}0.7%$ decrease in tyrosinase expression at melan-a cells. Colorimetric analysis showed a significantly lower depigmenting value by day 9 following treatment with RR in UVB-irradiated guinea pigs the dorsal skin (p<0.01), indicating that RR produced a depigmentation effect. By staining with Fontana-Masson stain, we found that the RR-treated group had more effect histopathologically in epidermal melanin production than resveratrol or rice alone-treated group. RR was associated with reduction in the levels of microphthalmia-associated transcription factor (MITF), and downregulation of tyrosinase and tyrosinase-related protein (TRP-2) expression, leading to inhibit epidermal melanin production by western blot analysis. This study suggests that the resveratrol-enriched rice may be a promising candidate in regulating skin pigmentation with UVB exposure.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.28 no.1
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• pp.135-149
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• 2002

To date, research on the regulation of melanogenesis has focused on factors which affect tyrosinase, the rate-limiting enzyme in the melanogenic pathway, by searching for chemicals which competitively inhibit tyrosinase function. Many types of tyrosinase inhibitors have been developed, but no satisfactory results have been made clinically until now, To find a new whitening agent, which effectively inhibits melanogenesis, we synthesized several compounds and selected compounds by cell-based assay system. Finally, 3, 4, 5-trimethoxy cinnamaie thymol ester(TCTE, Melasolv) was selected and the effects of TCTE on melanogenesis were investigated. Treatment of mouse-derived melanocyte melan-a cells with TCTE results in a marked down-regulation of tyrosinase activity. 80% decrease of tyrosinase activity occurs with 30uM TCTE treatment for 72 hours without affecting cell growth. The inhibition of tyrosinase activity is dose-dependent and melanin content was also decreased to 40%. From the in vitro tyrosinase assay using cell extract, TCTE does not act as a direct inhibitor of the enzyme. Treatment of melan-a cultures with TCTE blocks the increase in tyrosinase activity by either forskolin, 3-isobutyl-1-methtyl-xanthine. TCTE decreased the expression of tyrosinase, TRP-1 without effects on TRP-2 protein expression through the down regulation of tyrosinase and TRP-1 mRNA. From the results of cAMP immunoassays, intracellular levels of the cyclin nucleotide are unaffected in cells treated with TCTE. The inhibitory effects of melanin synthesis were also shown in reconstitute human epidermis model by topical application. These findings suggest that TCTE can be used for studying the regulation of melanogenesis and depigmenting agent.

• Interaction and multiscale mechanics
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• v.2 no.2
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• pp.177-187
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• 2009

Machine or structural members subjected to fatigue loading will have a crack initiated during early part of their life. Therefore analysis of members with cracks and other discontinuities is very important. Finite element method has enjoyed widespread use in engineering, but it is not convenient for crack problems as the region very close to crack tip is to be discretized with very fine mesh. However, as the body force method (BFM), requires only the boundary of the discontinuity (crack or hole) to be discretized it is easy versatile technique to analyze such problems. In the present work fundamental solution for concentrated load x + iy acting in the semi-infinite plate at an arbitrary point $z_0=x_0+iy_0$ is considered. These fundamental solutions are in complex form ${\phi}(z)$ and ${\psi}(z)$ (England 1971). These potentials are known as Melan potentials (Ramakrishna 1994). A crack in the semi-infinite plate as shown in Fig. 1 is considered. This crack is divided into number of divisions. By applying pair of body forces on a division, the resultant forces on the remaining 'N'divisions are to be found for which ${\phi}_1(z)$ and ${\psi}_1(z)$ are derived. Body force method is applied to calculate stress intensity factor for crack in semi-infinite plate. Also for the case of crack emanating from circular hole in semi-infinite plate radial stress, hoop stress and shear stress are calculated around the hole and crack. Convergent results are obtained by body force method. These results are compared with FEM results.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.1 s.49
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• pp.17-23
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• 2005

We had previously reported that Selina (selina-4(14), 7(11)-dien-8-one) was isolated from methanol extract of Afractylodes rhizome and has strong whitening activity in B16 melanoma cells. In this report, we demonstrated its action mechanism in melan-a cells, non-tumorigenic melanocytes. We also investigated the clinical efficacy of cosmetic preparation containing Selina. Selina reduced the melanin synthesis of Melan-a cells by $50\%$ at a concentration of $10 {\mu}g/mL$ without any apparent cytotoxicity. We also found that the treatment of cells with Selina decreased tyrosinase activity by $60\%$ at a concentration of $10 {\mu}g/mL$ but Selina was not a direct inhibitor of tyrosinase activities. To elucidate the action mechanism of Selina, we investigated the changes in mRNA and protein level of tyrosinase, TRP-1 and TRP-2 using RT-PCR and western blotting, respectively. As a result, the mRNA and protein level of tyrosinase were markedly reduced at $10 {\mu}g/mL$ of Selina without any effect on TRP-1 and TRP-2. These results suggest that Selina exerts its whitening effect mainly through regulating expression of tyrosinase. A 7 week-clinical trial using formulation containing $0.2\%$ selina-4(14), 7(11)-dien-8-one with 20 volunteers resulted in statistically significant whitening effect (p < 0.05), without any adverse effect. Based on these results, Selina (selina-4(14), 7(11)-dien-8-one) can be s useful and safe ingredient for the cleanness and brightness of skin.

• Preventive Nutrition and Food Science
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• v.21 no.2
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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.

• Journal of Ginseng Research
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• v.30 no.2
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• pp.82-87
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• 2006

Quantitative difference in five phenolic acids between white and red ginsengs was measured in this study. As the results, white ginseng has higher contents of cinnamic acid, quercetin and p-coumaric acid than red ginseng. Maltol was mainly included in red ginseng. These five compounds were recently reported to have tyrosinase inhibitory effects. These reports led us to investigate the de-pigmenting effect of ginseng products. In our examination of effect on tyrosinase activity, UV-protection and melanin production in melan-a cells, ethyl acetate traction of white ginseng extract and cinnamic acid showed potent de-pigmenting properties. The results indicated that white ginseng might be useful as skin whitening material and cinnamic acid proved to be one of active ingredient.