Melanosome Transport and Processing in Skin Pigmentation: Mechanisms and Targets for Pigmentation Modulation

Achieving even skin tone and controlling pigmentation are key goals in dermocosmetics, given the impact of disorders like melasma, post-inflammatory hyperpigmentation, and age spots. The process of pigmentation begins with melanin synthesis within melanosomes, specialized organelles in melanocytes. Once produced, melanin is transferred to neighboring keratinocytes, where it forms protective caps over cell nuclei before undergoing eventual degradation. Disruptions at any stage of this complex process, whether in melanin production, melanosome transport, or post-transfer processing, can lead to visible pigmentation irregularities. While traditional treatments primarily focus on inhibiting melanin production (e.g., through tyrosinase inhibitors), emerging research highlights the important role of melanosome transport and keratinocyte-mediated processing in determining visible pigmentation. This review focuses on the underexplored stages of melanosome transport, transfer, and keratinocyte-mediated processing as promising targets for therapeutic and cosmetic strategies in managing pigmentation disorders.