Modulation of dietary vitamins E and C fails to ameliorate b-carotene exacerbation of UV carcinogenesis in mice.

b-Carotene is a strong singlet oxygen quencher and, under most conditions, exhibits strong antioxidant properties. Based on these properties, and a number of epidemiological studies, it was suggested that an above average intake of the carotenoid might reduce cancer risks. Earlier studies had found that b-carotene, when added to commercial closed-formula rodent diets, provided significant photoprotection to ultraviolet light (UV) carcinogenesis.

Celecoxib, a cyclooxygenase 2 inhibitor as a potential chemopreventive to UV-induced skin cancer: a study in the hairless mouse model.

Objective: To assess the preventive effect of a cyclooxygenase 2 inhibitor, celecoxib (Celebrex; G.D. Searle & Co, Skokie, Ill), in UV-induced skin cancer in hairless mice.