Frontiers in Bioscience-Elite (FBE) is published by IMR Press from Volume 13 Issue 2 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with Frontiers in Bioscience.
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Academic Editor: King-Thom Chung
Frequently, aromatic amine (AA) contact to the skin occurs via occupational or ‘life style’ exposure to hair dye intermediates and couplers, usually monocyclic p-phenylenediamines and meta-substituted aminophenols. The transport of AA from the outer surface to the systemic circulation predominantly follows the intracellular route. Skin tends to have relatively higher phase II compared to phase I xenobiotic metabolizing enzyme capacity, and levels are generally regarded to be lower than those in liver are. Inside skin cells AA are primarily N-acetylated and detoxified by N-acetyltransferase 1. AA activation via hydroxylation or chemical oxidation competes with acetylation and is only of importance under circumstances when N-acetylation capacities are limited. The reactive AA derivatives are able to elicit effects by virtue of their modifications of skin proteins resulting in irritant or allergic contact dermatitis. Overall, the effective acetylation of topically applied AA in skin cells emphasizes a protective role of cutaneous acetylation mediating a classical “first-pass” effect, which attenuates systemic exposure.