Curcumin Inhibits Melanogenesis in Human Melanocytes

Abstract

Plant derived compounds, as potentially safe and effective skin lightening agents (SLAs), have attracted great attention from many researchers. Curcumin is a plant-derived polyphenol, which has been reported to suppress melanogenesis in B16 melanoma cells. However, little is known about whether curcumin affects melanogenesis in cultured human melanocytes. In addition, the molecular mechanism for the antimelanogenic effects of curcumin remains largely unknown. The present study assessed the effects of curcumin on melanin synthesis, cellular tyrosinase activity, the expression of melanogenesis-related proteins (microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein 1 and 2 (TRP-1, TRP-2)), and activation of melanogenesis-regulating signals including phosphatidylinositol 3-kinase (PI3K)/Akt/ glycogen synthase kinase 3 (GSK 3β), extracellular signal-regulated kinase (ERK) and p38 MAPK in human melanocytes. The results showed that the melanin content and tyrosinase activity, as well as the expression of melanogenesis-related proteins in human melanocytes, were significantly inhibited by curcumin in a dose dependent manner. In addition, PI3K/Akt/ GSK 3β, ERK and p38 MAPK were activated by curcumin, while inhibitors of these signals attenuated the inhibitory effects of curcumin on melanogenesis. These results suggest that curcumin inhibits melanogenesis in human melanocytes through activation of Akt/GSK 3β, ERK or p38 MAPK signaling pathways.

Cinnamomum cassia Essential Oil Inhibits α-MSH-Induced Melanin Production and Oxidative Stress in Murine B16 Melanoma Cells

“…Therefore, antioxidants, tyrosinase inhibitors, or ROS scavengers may down-regulate melanogenesis. Many previous studies have reported that various antioxidants, including gallic acid [8], vanillin [9], curcumin [11], and ascorbic acid [31], may produce anti-melanogenic effects. Previous studies have demonstrated that both extracts and essential oils from C. cassia exhibit antioxidant activity [32,33].…”

“…Therefore, the increasing desire of skin whitening agents from synthetic [4,5] or natural [6,7] resources for both beauty and therapeutic purposes is under development. Plant-derived compounds including gallic acid [8], vanillic acid [9], eugenol [10], and the recently characterized substance of curcumin [11] have been reported to possess anti-melanogenic abilities.…”

Norartocarpetin from a folk medicine Artocarpus communis plays a melanogenesis inhibitor without cytotoxicity in B16F10 cell and skin irritation in mice

“…These tyrosinase-related proteins are the rate-limiting enzymes of melanogenesis and increase (1) the conversion of tyrosine to dopaquinone, (2) the rearrangement of DOPAchrome to 5,6-dihydroxy-indole-2-carboxylic acid, and (3) the overproduction and accumulation of melanin pigments in skin. Therefore, skin whitening ingredients such as paeonol [30] and curcumin [31] are effectively downregulated p-CREB and MITF proteins, as well as inhibited tyrosinase synthesis, so as to decrease melanin production. Our results demonstrate that norartocarpetin significantly downregulated the level of p-CREB, MITF, and its related proteins, including TYR, TRP1, and TRP2, in a dose-dependent manner.…”

Extracts ofArtocarpus communisDecreaseα-Melanocyte Stimulating Hormone-Induced Melanogenesis through Activation of ERK and JNK Signaling Pathways

“…Previous studies have also shown that the MAP kinase family, including ERK and JNK, plays an important role in regulating melanogenesis [22, 23]. Many publications have demonstrated that efficacious inhibitors of melanogenesis activate the phosphorylation of ERK and JNK and result in the phosphorylation of MITF at serine 73, which induces subsequent ubiquitin-dependent proteasomal degradation [24].…”