The Wave Length Effect Upon Erythemal and Carcinogenic Response in Psoralen Treated Mice11From the Department of Biochemistry, The University of Texas M.D. Anderson Hospital and Tumor Institute and the Departments of Biochemistry and Dermatology, Baylor University College of Medicine, Houston, Texas. Supported by grants from the Robert A. Welch Foundation, Humble Oil and Refining Company and the National Cancer Institute (NCI 2620), U. S. Department of Health, Education and Welfare

The powdered fruit of Ammi majus L. of the Umbelliferae family have been used for several centuries in the treatment of leukoderma and other pigmentation disorders (1). Fahmy and associates (2-4), and Schonberg and Sina (5, 6) have isolated the active components and identified them as psoralen derivatives. More recently, Fitzpatrick et al (7) demonstrated the effectiveness of 8-methoxypsoralen (8-MP) in pigment formation in individuals exposed to total sunlight or ultraviolet irradiation. These investigators have also shown that pigment production may be obtained following either oral or topical applications of this drug with a response that is roughly proportional to the dose administered.