Genotoxicity of 5-methoxypsoralen and near ultraviolet light in repair-deficient strains of Escherichia coli WP2.
5-Methoxypsoralen (5-MOP) is used in cosmetic suntan preparations to stimulate the production of skin pigments. Although its isomer 8-methoxypsoralen (8-MOP) has been shown to be genotoxic in numerous biological systems, 5-MOP has not been so extremely investigated, but it has recently been reported to be mutagenic and carcinogenic. We have studied the lethal effects of 5-MOP and near ultraviolet light (NUV) on repair-deficient Escherichia coli strains. After treatment with 5-MOP at concentrations above 2 microgram/ml in combination with UV light survival of the repair-deficient strains was considerably reduced and strain WP100 UVRA- recA- was more sensitive than strain WP2 UVRA-. The effect was dependent on the time of irradiation and on the presence or absence of S-9 mix which inhibited the lethal activity of 5-MOP/NUV particularly when the NADP-generating system was included. These results support other indications that the use of 5-MOP in cosmetic preparations should be controlled.
D000078223:5-Methoxypsoralen; D000818:Animals; D004260:DNA Repair; D004926:Escherichia coli / Q000187:drug effects*; D008297:Male; D008730:Methoxsalen / Q000633:toxicity*; D051381:Rats; D014466:Ultraviolet Rays / Q000009:adverse effects*
D000078223:5-Methoxypsoralen; D008730:Methoxsalen