Minireview: Peptide analogs and short sequence oligopeptides as modulators of skin pigmentation

Short sequence amino acids or oligopeptides have recently garnered attention for use as treatments for a myriad of dermatologic disorders due to their ability to effect and modulate various biological processes in the epidermis and dermis, rendering them promising candidates as medical and cosmeceutical therapeutics. Major advantages include their relative ease of synthesis and multitude of modifications that can be applied to enhance potency, affinity, specificity, hydrophilicity or hydrophobicity and cytotoxicity. Given the photoprotective effects of eumelanin on skin, there has been substantial interest in developing agents, particularly α-MSH analogs, that can induce 'sunless tanning' helping reduce risk of melanoma and non-melanoma skin cancer. In this mini review, we present some of the recent and leading peptide modulators of melanogenesis with relevant clinical data and medical indications. Short sequence oligopeptides with tyrosinase inhibitory activity that can significantly reduce hyperpigmentation, as well α-MSH analogs that can enhance eumelanogenesis, are currently being clinically tested for treatment of erythropoietic protoporphyria, polymorphous light eruption, solar urticaria, actinic keratosis, and "sunless tanning". Success in developing such products can help reduce the incidence of skin cancer, one that surpasses that of all other human cancers combined.