Melanocytes as instigators and victims of oxidative stress.

Epidermal melanocytes are particularly vulnerable to oxidative stress owing to the pro-oxidant state generated during melanin synthesis, and to the intrinsic antioxidant defenses that are compromised in pathologic conditions. Melanoma is thought to be oxidative stress driven, and melanocyte death in vitiligo is thought to be instigated by a highly pro-oxidant state in the epidermis. We review the current knowledge about melanin and the redox state of melanocytes, how paracrine factors help counteract oxidative stress, the role of oxidative stress in melanoma initiation and progression and in melanocyte death in vitiligo, and how this knowledge can be harnessed for melanoma and vitiligo treatment.