Skin whitener offers soothing properties

19. Dumont, C. Garcia, M. Puginier, C. Stoltz, R. Roso, H. Geoffroy,
20. Trouve, Y. Duccini, B. Brancq – Seppic, France
21. Khaiat – Seers Consulting, USA

Melanocytes, located in the suprabasal layer of epidermis, produce two types of melanin; i.e. brown-black eumelanin and red-yellow phaeomelanin, responsible for skin colouration. Melanin is also known to confer photoprotection on the skin. Each melanocyte is surrounded by 36 keratinocytes, forming a so-called epidermal-melanin unit. Melanin is produced in specialised intracellular melanocyte membrane-coated organelles that originate from the endoplasmic reticulum, i.e. the melanosomes. These organelles contain tyrosinase, which is the rate-limiting enzyme for melanogenesis. Indeed tyrosinase catalyses the conversion of L-tyrosine to dopaquinone, which is required for the synthesis of both melanin types. Melanosomes are further transferred to neighbouring keratinocytes which can then bring melanin to the different epidermal cell layers while differentiating and migrating to the epidermal surface.