title: Photochemotherapy (PUVA) of psoriasis using 3-carbethoxypsoralen, a non-carcinogenic compound in mice.
abstract: The carcinogenic risk of photochemotherapy (PUVA) with bi-functional furocoumarins such as 8-methoxypsoralen (8-MOP) which form cross-links in cellular DNA has initiated a search for active but less hazardous psoralens. A new compound, 3-carbethoxypsoralen (3-CPs), studied in the yeast Saccharomyces cerevisiae (eukaryote), has been shown to be very photoactive on DNA and to form only mono-additions to DNA. These lesions appear to be more easily repaired than the cross-links induced by 8-MOP. 3-CPs produces less nuclear genetic events such as nuclear mutations and mitotic crossovers, but more cytoplasmic 'petite' mutations (damage to mitochondrial DNA) than 8-MOP. In mice it was demonstrated that after local or intra-peritoneal administration, in contrast to 8-MOP, 3-CPs is non-toxic, non-erythematogenic, and non-carcinogenic. A study of ten psoriatic patients had shown that local applications of 3-CPs plus UV-A exhibit about the same therapeutic activity for the clearing of psoriatic lesions as local treatment with 8-MOP plus UV-A, but without any localized hyperpigmentation.
mesh_terms: D000818:Animals; D004271:DNA, Fungal; D004353:Drug Evaluation, Preclinical; D005260:Female; D011564:Furocoumarins / Q000009:adverse effects / Q000627:therapeutic use* / Q000633:toxicity; D006801:Humans; D008297:Male; D008730:Methoxsalen / Q000627:therapeutic use; D051379:Mice; D010778:Photochemotherapy; D010787:Photosensitivity Disorders / Q000139:chemically induced; D011565:Psoriasis / Q000188:drug therapy*; D012441:Saccharomyces cerevisiae / Q000187:drug effects; D012878:Skin Neoplasms / Q000139:chemically induced
chemical_list: D004271:DNA, Fungal; D011564:Furocoumarins; D008730:Methoxsalen