Inhibitory effects of Saururi chinensis extracts on melanin biosynthesis in B16F10 melanoma cells.
(6/10)
Saururus chinensis has been used in folk medicine in Korea for the treatment of edema, jaundice, gonorrhea, and several inflammatory diseases. Saururi chinensis extracts (SCE) have demonstrated anti-inflammatory and anti-oxidant activities, as well as anti-asthmatic, antihypertensive, anti-angiogenic, and therapeutic activities for atopic dermatitis. However, the inhibitory activity of SCE on the melanogenesis signaling pathway is not completely understood. This study examined the effects of SCE on the melanogenesis signaling pathway activated by alpha-melanocyte-stimulating hormone (alpha-MSH). We found that SCE inhibited melanin production in a dose-dependent manner without causing cytotoxicity in B16F10 cells. Interestingly, SCE decreased alpha-MSH-induced tyrosinase activity in B16F10 cells but did not inhibit tyrosinase activity under cell-free conditions. The results of this study indicate that SCE may reduce pigmentation by way of an indirect, nonenzymatic mechanism. We also found that SCE decreased alpha-MSH-induced microphthalmia-associated transcription factor (MITF) and tyrosinase expression and induced the activation of extracellular signal-regulated kinase (ERK). These results suggest that the depigmenting effect of SCE may result from downregulation of MITF and tyrosinase expression due to increased ERK activity. Thus, our results provide evidence that SCE might be useful as a potential skin-whitening agent. (+info)
Examining the impact of skin lighteners in vitro.
(7/10)
Analysis of the effects of hydroquinone and arbutin on the differentiation of melanocytes.
(8/10)
Hydroquinone (HQ) is a chemical compound that inhibits the functions of melanocytes and has long been known for its skin-whitening effect. According to previous studies, the Tyrosinase (Tyr) activity inhibitory effect and melanocyte-specific cell toxicity are known depigmenting mechanisms; however, details of the underlying mechanisms are unknown. Arbutin (Arb) is also known for its Tyr activity inhibitory effect and is commonly used as a skin-whitening agent. However, the detailed depigmenting mechanism of Arb is also not yet fully understood. Few studies have attempted to elucidate the effects of HQ and Arb on undifferentiated melanocytes. In this study, we examined the effects of HQ and Arb throughout each stage of differentiation of melanocytes using a mouse embryonic stem cell (ESC) culture system to induce melanocytes. The results showed that HQ in particular downregulated the early stage of differentiation, in which neural crest cells were generated, and the late stage of differentiation, in which melanogenesis became active. On the other hand, Arb had no effect on the differentiation of melanocytes, and only suppressed melanogenesis by specifically suppressing elevations in Tyr expression in the late stage of differentiation. (+info)