• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.3
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• pp.249-258
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• 2018

Airborne pollution causes oxidative damage, inflammation, and premature aging of skin. Resveratrol is a polyphenol compound that has various biological activities such as antioxidant, anti-inflammation, and anti-melanogenic activities but it is unstable to heat and light. Resveratryl triacetate (RTA) is a new cosmetic ingredient that is more stable than resveratrol and its skin safety and whitening efficacy have been reported previously. The purpose of this study was to examine the effects of resveratrol and resveratryl triacetate (RTA) on the inflammatory responses of human epidermal keratinocytes (HEKs) exposed to airborne particulate matters with a diameter of < $10{\mu}m$ (PM10). Cultured HEKs were exposed to PM10 in the absence or presence of resveratrol and RTA. Assays were undertaken to determine cell viability, the production of reactive oxygen species (ROS), and the expression of inflammatory cytokines. PM10 treatment decreased cell viability, and increased the expression of pro-inflammatory cytokines such as tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), $interleukin-1{\beta}$ ($IL-1{\beta}$), interleukin-6 (IL-6), and interleukin-8 (IL-8). Resveratrol and RTA reduced cell death and ROS production induced by PM10. PM10-induced mRNA expression of the inflammatory cytokines was either attenuated (IL-6), or enhanced ($IL-1{\beta}$), or unaffected ($TNF-{\alpha}$ and IL-8) by resveratrol and RTA. PM10-induced IL-6 protein expression was attenuated by resveratrol and RTA. This study suggests that resveratrol and RTA have activities regulating cell damage and inflammatory responses of the skin exposed to airborne particulate matters.

• Horticultural Science & Technology
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• v.29 no.4
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• pp.358-365
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• 2011

Lespedeza cuneata G. Don is a plant commonly grown in Asian countries, which has been widely used as an oriental medicinal herb to treat diabetes, diarrhea and various other inflammatory diseases. The phenolics of dry leaves of L. cuneata G. Don were extracted by using 80% (v/v) aqueous methanol in assistance with homogenization and sonification. The phenolic extract and its five different fractions (n-hexane, chloroform, ethyl acetate, n-butanol, and water) were used to evaluate the levels of total phenolics, total flavonoids, and antioxidant capacity as well as the inhibitory effect of tyrosinase activity. Ethyl acetate fraction (1 g) had the highest levels of total phenolics at 240.8 mg gallic acid equivalents (GAE), total flavonoids as 90.4 mg catechin equivalents (CE) as well as antioxidant capacity at 523.4 mg vitamin C equivalents (VCE) on ABTS assay and 329.5 mg VCE on DPPH assay among fractions. One g of water fraction contained total phenolics at 133.1 mg GAE, total flavonoids at 34.5 mg CE, and antioxidant capacity at 333.4 mg VCE for ABTS assay and 313.2 mg VCE for DPPH assay. Inhibition of tyrosinase activity of water fraction at 300 ${\mu}g{\cdot}mL^{-1}$ was at 47.2% and 21.1% for L-tyrosine and L-DOPA as its substrate, respectively. On the other hand, ethyl acetate fraction at 300 ${\mu}g{\cdot}mL^{-1}$ showed tyrosinase inhibition of 10.2% for L-tyrosine and 11.9% for L-DOPA. These results suggested that the phenolics from dry leaves of L. cuneata G. Don may be utilized as a potent source of antioxidants and skin whitening agents.

• Journal of Life Science
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• v.27 no.2
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• pp.139-148
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• 2017

The inhibition of tyrosinase, a key enzyme in mammalian melanin synthesis, plays an important role in preventing skin pigmentation and melanoma. Therefore, tyrosinase inhibitors are very important in the fields of medicine and cosmetics. However, only a few tyrosinase inhibitors are currently available because of their toxic effects on skin or lack of selectivity and stability. Therefore, we synthesized a novel series of (E)-2-(substituted benzylidene)-2,3-dihydro-1H-cyclopenta[a]naphthalen-1-one derivatives and evaluated their inhibitory effects on mushroom tyrosinase, with the aim of discovering a novel tyrosinase inhibitor. Among 19 derivatives, MHY3655 ($IC_{50}=0.1456{\mu}M$) showed the strongest inhibitory effect on tyrosinase activity compared to kojic acid ($IC_{50}=17.2{\mu}M$), a well-known tyrosinase inhibitor. In addition, MHY3655 showed competitive inhibition on Lineweaver-Burk plots. We confirmed that MHY3655 strongly interacts with mushroom tyrosinase residues through the docking simulation. Substitutions with a hydroxy group at both R2 and R4 in the phenyl ring indicated that these groups play a major role in the high binding affinity to tyrosinase. Further, MHY3655 did not show cytotoxicity at the concentrations tested in B16F10 melanoma cells. In conclusion, the novel compound MHY3655 potentially shows tyrosinase inhibitory activity, and it could be used as an ingredient in whitening cosmetics.