Ganoderma lucidum, a species of the class Basidiomycetes, attracts international attention due to the wide variety of its biological activities and great potential as cosmetic ingredient, such as skin care cosmetics including ‘skin-whitening’. However, there is little information available regarding the tyrosinase inhibitory activity. Therefore, the objectives of this study were to investigate the chemical composition and tyrosinase inhibitory activity of the G. lucidum. To isolate active single compound from G. lucidum (GASC), we conducted ethanol extraction and chloroform fractionation. In addition, we assayed the inhibitoty effect of tyrosinase activity and melanin biosynthesis in B16F10 mouse melanoma cells. In the present study, we identified a GASC, which exhibited inhibitory effects of cellular tyrosinase activity, the protein expression of cellular tyrosinase and tyrosinase-related protein-1, 2. In additional, microphthalmia-associated transcription factor (MITF), as known as crucial regulator of melanogenesis-related genes, was down-regulated by treatment with GASC in a concentration-dependent manner. GASC exhibited significant inhibition of tyrosinase activity and melanin synthesis in B16F10. The finding that melanogenesis inhibitory effect of GASC will contribute to facilitate various approaches of this mushroom for use in skin whitening products.

Recently many efforts were focused to understand the mechanical insights of melanogenesis to develop the agents for hyper-pigmentation and hypo-pigmentation. In the melanin biosynthetic pathway, tyrosinase is the rate limiting enzyme, and α-melanocyte stimulating hormone(MSH) stimulate melanogenesis and enhance the melanin synthesis and the tyrosinase activity. This study the effects of Radix Trichosanthis on the basal melanogenic activities of B16/F10 mouse melanoma cells, and on the α-MSH induced melanogenesis. Radix Trichosanthis alone markedly suppressed melanin content and tyrosinase activity in a dose-dependent manner. Pretreatment of the cells with Radix Trichosanthis also suppressed the increase of α-MSH (10 nM) induced melanin content and tyrosinase activity. These results suggest that Radix Trichosanthis inhibits melanogenesis and abrogates α-MSH induced melanogenesis in B16 melanoma cells.

The pathological condition of excessive melanogenesis causing freckles, melasma, senile lentigo, pigmented acne scars, and cancer has a critical impact on the wellness of individuals. The mechanism of melanogenesis is related to the expression of melanogenic enzymes. Here, we evaluated the inhibitory effect of pine cone (Pinus densiflora) extracts on melanogenesis. P. densiflora, the Korean Red Pine, is the predominant tree species in the cool, temperate forests of northeast Asia, occurring in pure stands across Korea, Japan, and parts of northern China and Russia. P. densiflora leaves, pollen, and bark have been widely used for traditional medicine, or edible purposes. However, pine cones are rarely used as natural raw materials, although they contain many bioactive phytochemicals. The pine cone ethyl acetate fraction (PEF) showed no toxicity to B16F10 cells at a concentration of less than 100 ㎍/mL. PEF inhibited the expression of microphthalmiaassociated transcription factor (MITF), tyrosinase and tyrosinase-related factors in B16F10 cells treated with 3-Isobutyl- 1-methylxanthine (IBMX). These results suggest that pine cones can be used as an effective natural melanogenesis inhibitory agent.

This study was conducted to investigate the effect of branch extracts of Vaccinium oldhamii (VOB) on melanin synthesis in B16F10 cells. VOB promoted melanin production in absence or presence of α-melanocyte-stimulating hormone (α-MSH) in B16F10 cells. However, VOB did not affect the expression of tyrosinase and TRP-1 associated with melanin synthesis at the mRNA and protein levels in B16F10. But, VOB decreased TRP-2 protein level and induced tyrosinase activation in B16F10 cells. Inhibition of tyrosinase activity and tyrosinase knockdown attenuated VOB-mediated melanin synthesis. In conclusion, VOB may stimulate melanin synthesis through activating tyrosinase activity.

본 연구에서는 약콩(Glycine soja Siebold et Zucc.) 분획 추출물의 미백효능을 관찰하기 위해 B16F10 멜라노마 세포에서 TRP-1 (tyrosinase related protein-1), TRP-2 (tyrosinase related protein-2), 티로 시나제 발현을 평가하였다. 그 결과 약콩 분획 추출물 0.125, 0.25, 0.5, 2.0 mg/mL 농도에서 82% 이상의 높 은 세포생존율을 나타내었다. α-melanocyte stimulating hormone (α-MSH)을 처리한 B16F10 멜라노마 세포에 약콩의 EtOAc 분획 추출물을 처리한 결과 티로시나제 발현이 감소되었으며 TRP-1, TRP-2 단백질 발현이 감소하였다. 이러한 결과는 약콩 분획 추출물이 멜라닌생합성과 관련되는 단백질의 발현을 감소시켜 피 부 미백효능을 나타내는 것으로 기대할 수 있다.

Dendrobium loddigesii (DL) is a valuable and versatile herbal medicine with the anecdotal claims of anti-oxidant and anti-inflammation. In the present study, we investigated the whitening effects of DL under various conditions with B16F10 melanoma cells. The DL extract inhibited melanin contents and tyrosinase activity in a dose-dependent manner, compared with untreated group. Treatment of the DL extract effectively suppressed the α-MSH-stimulated melanin formation, tyrosinase activity and dendrite outgrowth. Moreover, the α-MSH-induced mRNA expressions of tyrosinase-related protein-1 (TRP-1), tyrosinase-related protein-2 (TRP-2), microphthalmia-associated transcription factor (MITF) and protein expression of tyrosinase were significantly attenuated by DL treatment. These results indicate that DL may be a great cosmeceutical ingredient for its whitening effects.

본 연구에서는 B16 악성흑색종 세포에서 디펩타이드(dipeptide)의 멜라닌생성 저해 효과를 연구하였다. 실험결과 WV (트립토판-발린), WM (트립토판-메치오닌), CQ (시스테인-글루타민)는 멜라닌 생성을 농도 의존적으로 감소 시켰다. 그러나 디펩타이드는 멜라닌 생합성과정의 속도 조절 단계 효소인 타이로시네이즈(tyrosinase)의 활성을 직접 감소시키지는 않았다. 따라서 타이로시네이즈의 발현양상을 조사하였고, 실험 결과 α-MSH가 유도한 타이로시네이즈 발현이 WV, WM, 그리고 CQ에 의해 억제되었다. 그러므로 WV, WM, 그리고 CQ가 타이로시네이즈의 억제성 조절 (down-regulation)을 통해 멜라닌 생성을 감소시킨다고 제안될 수 있다.

Glycogen synthase kinase 3 beta (GSK3β)의 선택적 저해제인 Kenpaullone가 B16 멜라노마 및 사람의 멜라노 사이트에 미치는 멜라닌 합성능을 조사하였다. Kepaullone은 B16 멜라노마 및 사람의 멜라노사이트에 대하여 세포증식에는 영향이 없는 범위 내에서 농도 의존적으로 멜라닌 합성을 촉진시켰다. B16 멜라노마 세포에 Kenpaullone을 첨가 48 h 후 tyrosinase 활성이 증가하였으며, 농도별 처리에 대하여 tyrosinase 단백질의 발현 및 tyrosinase mRNA양이 증가함을 관찰하였다. 결론적으로 Kenpaullone는 B16 멜라노마 세포에서 tyrosinase 효소의 발현을 증가시켜 멜라닌 합성을 촉진하는 것으로 판단되어진다. 따라서 GSK3β 저해제가 멜라닌 합성을 촉진시키는 결과는 백반증과 같은 저색소관련 질병의 치료제 개발의 가능성을 갖고 있는 소재로서 응용가능하리라고 판단되어진다.