ABSTRACT
Psoralens are a group of phototoxic compounds that can interact with various components of cells and then absorb photons to produce photochemical reactions that alter the function of cellular constituents. Psoralens belong to the furocoumarin group of compounds and the parent compound, psoralen, and many of its derivatives are naturally occurring compounds found in a large number of plants. Psoralens are poorly soluble in water and this is a limiting factor in their absorption from the gastrointestinal tract. Psoralens are subject to a significant but saturable first-pass effect in the liver. Psoralens are mainly used in combination with broadband sources of ultraviolet (UV) A radiation. Pigmentation after oral administration of psoralen and exposure to UVA radiation is usually darker and lasts longer than the tan associated with a comparable UVB-induced erythema. Psoralens enter the eye and UVA radiation is absorbed by the lens, so cataracts are a risk after repeated phototoxic insults.
