Understanding Mechanisms and Key Factors Influencing Melanogenesis for the Management of Melasma: An Updated Review.

Melanocytes are highly specialized dendritic cells that deliver melanin to keratinocytes in melanosomes, which are subcellular organelles where melanin is produced and stored. Mammal's skin, hair, and eyes all contain the complex pigment melanin, which gives them color and ultraviolet protection. Melanins have the potential to be free radical sinks and are strong cation chelators. Amino acid tyrosine and its metabolite, dopa, are the precursors to complex metabolic processes that end with melanin production. Melanocytes generate different types and amounts of melanin, which is defined genetically and is impacted by several extrinsic and intrinsic factors such as hormone fluctuations, inflammation, age, and ultraviolet radiation exposure, leading to the stimulation of numerous melanogenesis pathways. Melasma, a common skin pigmentation condition, is associated with the overproduction of melanin and is characterized by brown to gray-brown and black spots that mostly affect the face. The present review addresses the regulatory mechanisms and signaling pathways involved in skin pigmentation with an emphasis on the altered melanogenesis that causes melasma and hyperpigmentation. The current study also illustrates the available treatment options with cellular and molecular mechanisms for the management of melasma. Understanding the mechanism of the pigmentation process may help researchers develop new therapeutic strategies and novel drugs for the management of melasma.