• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.4 s.54
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• pp.305-310
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• 2005

To obtain effective and safe depigmenting agents, we investigated the effects of Scirpi rhizoma, a medicine among Chinese herbs, on melanogenesis. Dried S. rhizoma was refluxed with 70% aqueous ethanol and the extract was evaporated to dryness. To determine the effects as a whitening agent, various in vitro tests were performed such as free radical scavenging activity, melanin formation assay, tyrosinase activity and expression of tyrosinase, TRP-1 and TRP-2(western blot and RT-PCR) in B16 melanoma cells. S. rhizoma showed scavenging activities of free radicals and reactive oxygen species (ROS) with the $IC_{50}\;of\;638{\mu}g/mL$ against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and $21.7{\mu}g/mL$ against superoxide radicals in the xanthine/xanthine oxidase system, respectively. S. rhizoma significantly inhibited melanin production in B16 melanoma cells. S. rhizoma treatment(48 h) suppressed the biosynthesis of melanin up to 27% at 100{\mu}g/mL$ and reduced tyrosinase activity up to 31% at $100{\mu}g/mL$ in B16 melanoma cells. S. rhizoma was also able to significantly inhibit tyrosinase and TRP-1 expression in protein and mRNA level. These results suggest that S. rhizoma inhibited melanin biosynthesis by regulating tyrosinase activity and expression in B16 melanoma cells. Therefore, S. rhizoma may be useful as a new antioxidant and whitening agent to inhibit melanogenesis.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.1
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• pp.11-24
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• 2022

It has been reported that the ethanolic extract of the root of Piper methysticum (P. methysticum) inhibits melanogenesis in melanocyte stimulating hormone (MSH)-activated B16 melanoma cells. Flavokawain B (FKB) and Flavokawain C (FKC) isolated from this extract have been found to inhibit melanin production based on anti-melanogenesis activity. This study was designed to find out the inhibition and its process of FKB and FKC on melanin synthesis in melan-a melanocytes. FKB and FKC inhibited melanogenesis at 10 μM, 5 μM respectively in melan-a melanocytes. However, they did not inhibit extracellular tyrosinase activity from melan-a melanocytes. FKB reduced the protein level of tyrosinase (Tyr), tyrosinase-related protein 1 (TRP-1), tyrosinase-related protein 2 (TRP-2), microphthalmia-associated transcription factor (MITF) and the mRNA level of Tyr and TRP-1. FKC reduced the protein level of TRP-2 and MITF and the mRNA level of TRP-1 and Tyr. The reduced expression of Tyr and TRP-1 might be resulted from the decreased MITF which regulates major melanogenic proteins. However, since the mRNA expression of MITF did not change by FKB and FKC treatment, the effects of FKB and FKC on extracellular signal regulating kinase (ERK)/AKT phosphorylation, known to regulate the degradation of MITF, were confirmed. FKB and FKC significantly increased the phosphorylation of ERK1/2, not in AKT. These results suggest that FKB and FKC may be helpful as a potential depigmenting agent for various hyper-pigmentary disorders.

• Journal of Radiation Protection and Research
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• v.36 no.2
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• pp.93-98
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• 2011

We induced the activation of melanocytes in the epidermis of C57BL/6 mice by ultraviolet-B (UV-B) irradiation, and observed the effect of an herbal preparation (HemoHIM, HH) on the formation, and decrease of UV-B-induced epidermal melanocytes. C57BL/6 mice were irradiated by UV-B $80\;mJ{\cdot}cm^{-2}$ ($0.5\;mW{\cdot}sec^{-1}$) daily for 7 days, and HH was intraperitoneally, orally or topically applied pre- or post-irradiation. For the estimation of change of epidermal melanocytes, light microscopic observation with dihydroxyphenylalanine (DOPA) stain was performed. Split epidermal sheets prepared from the ear of untreated mice exhibited 13~15 melanocytes${\cdot}mm^{-2}$, and one week after UV irradiation, the applied areas showed an increased number of strongly DOPA-positive melanocytes with stout dendrites. But intraperitoneal, oral or topical treatment with HH before each irradiation interrupted UV-B-induced pigmentation and resulted in a marked reduction in the number of epidermal melanocytes as compared to the number found in UV-B-irradiated, untreated control skin. The number and size of DOPA-positive epidermal melanocytes were also significantly decreased in intraperitoneally injected or topically applicated group after irradiation with HH at 3rd and 6th weeks after irradiation. The present study suggests the HH as inhibitor of UV-B-induced pigmentation, and depigmenting agent.