Ethyl linoleate inhibits α-MSH-induced melanogenesis through Akt/GSK3β/β-catenin signal pathway

Ethyl linoleate is an unsaturated fatty acid used in many cosmetics for its various attributes, such as antibacterial and anti-inflammatory properties and clinically proven to be an effective anti-acne agent. In this study, we investigated the effect of ethyl linoleate on the melanogenesis and the mechanism underlying its action on melanogenesis in B16F10 murine melanoma cells. Our results revealed that ethyl linoleate significantly inhibited melanin content and intracellular tyrosinase activity in α-MSH-induced B16F10 cells, but it did not directly inhibit activity of mushroom tyrosinase. Ethyl linoleate inhibited the expression of microphthalmia-associated transcription factor (MITF), tyrosinase, and tyrosinase related protein 1 (TRP1) in governing melanin pigment synthesis. We observed that ethyl linoleate inhibited phosphorylation of Akt and glycogen synthase kinase 3β (GSK3β) and reduced the level of β-catenin, suggesting that ethyl linoleate inhibits melanogenesis through Akt/GSK3β/β-catenin signal pathway. Therefore, we propose that ethyl linoleate may be useful as a safe whitening agent in cosmetic and a potential therapeutic agent for reducing skin hyperpigmentation in clinics.