Psoralen Derivatives with Enhanced Potency.

Psoralen is a furocoumarin natural product that intercalates within DNA and forms covalent adducts when activated by ultraviolet radiation. It is well known that this property contributes to psoralen's clinical efficacy in several disease contexts, which include vitiligo, psoriasis, graft-versus-host disease and cutaneous T-cell lymphoma. Given the therapeutic relevance of psoralen and its derivatives, we attempted to synthesize psoralens with even greater potency.

UVA and UVB-Induced 8-Methoxypsoralen Photoadducts and a Novel Method for their Detection by Surface-Enhanced Laser Desorption Ionization Time-of-Flight Mass Spectrometry (SELDI-TOF MS).

UVA-activated psoralens are used to treat hyperproliferative skin conditions due to their ability to form DNA photoadducts, which impair cellular processes and may lead to cell death. Although UVA (320-400 nm) is more commonly used clinically, studies have shown that UVB (280-320 nm) activation of psoralen can also be effective. However, there has been no characterization of UVB-induced adduct formation in DNA alone.

UV doses of young adults.

Since 1986, people have been informed that they get about 80% of their lifetime ultraviolet (UV) dose by the age of 18. This belief originated from the mathematical conclusion that diligent use of sunscreens (sun protection factor 15 or higher) during the first 18 years of life would reduce the lifetime incidence of nonmelanoma skin cancers by 78%. These data were misconstrued to mean that individuals also got about 80% of their lifetime dose of UV by the age of 18 (linear relationship).

Photochemotherapy of vascular cells with 8-methoxypsoralen and visible light: differential effects on endothelial and smooth muscle cells.

Background: The long-term efficacy of percutaneous transluminal coronary angioplasty is limited by the restenosis which occurs in approximately 40% of patients, usually within 6 months of the procedure.

Purpose: The present study was designed to evaluate the effects of 8-methoxypsoralen (8-MOP) activated with visible light on the properties of bovine aortic smooth muscle cells (SMC) and endothelial cells (EC) in vitro.

Methods: Cells were seeded in polystyrene wells, allowed to attach over a 24-h period, incubated with 1, 20, or 50 microg/ml 8-MOP and then exposed to 12 J/cm2 visible light (447 nm).