Curcumin Inhibits UV Radiation–Induced Skin Cancer In Vivo

Abstract

Objective: As skin cancer incidence increases, research has focused on novel chemopreventive agents that inhibit tumor formation. In prior experimentation, curcumin, a naturally occurring food substance and anti-carcinogenic agent, inhibited cutaneous squamous cell carcinoma xenograft growth. We hypothesize curcumin will inhibit UVB-radiation–induced skin cancer growth in mice, approximating a human chemopreventive model. Method: A randomized experimental animal and laboratory study is presented. SKH-1 mice were pre-treated with oral or topical curcumin, or oral or topical control (n = 22/group), for 14 days. Mice received UVB radiation 3 times weekly for 24 weeks or were not radiated. Tumor number, volume, and onset were compared. Results: Time to tumor onset was significantly shorter in control mice compared to mice receiving either oral ( P = .025) or topical ( P = .015) curcumin. A significant difference in the average number of tumors formed per mouse was seen, as fewer tumors were formed in the oral curcumin ( P = .01) and topical curcumin ( P = .01) groups, compared with their respective controls. Once tumors formed, no significant difference in tumor volume was noted at 24 weeks. Conclusion: Curcumin appears to inhibit skin cancer formation and prolong time to tumor onset when administered by either an oral or topical route. These data suggest that curcumin may have chemopreventive potential against skin cancer necessitating future experimentation with human subjects.