Active Vitamin D3 Ointments Suppress Ultraviolet B Irradiation-Induced Papilloma Formation in Mouse Skin

Background: Topical application of 1a, 25-dihydroxyvitamin D3 (1-a,25-(OH)2D3) inhibits7, 12-dimethylbenz [a] anthracene (DMBA) and 12-a-tetradecanoylphorbol-13-acetate (TPA)-induced tumor formation of mouse skin. Ultraviolet irradiation (UV) may also induce skin tumors. However, no report exists regarding the effect of topical active vitamin D3, tacrolimus, or corticosteroids on UV-irradiation-induced skin tumors. 1.2. Objective Using ultraviolet B (UVB)-induced papilloma model, we compared the effect of active vitamin D3, tacrolimus, and corticosteroid ointments on the skin papilloma formation. Methods: Various corticosteroids (betamethasionevalelate, betamethasonebutyrate propionate), active vitamin D3 (tacalcitol, carcipotriol, maxacalcitol), tacrolimus, or white petrolatum ointments were applied twice a week on the mice skin following UVB-irradiation (200mJ/cm2). The number of UVB-induced skin papillomas was counted at the indicated time. Results: Papillomas were induced at 12 weeks on the UVB-irradiated mouse skin. The number of papilloma was significantly decreased on active vitamin D3 ointment-treated mice skin. However, the anti-tumor effect was not observed on corticosteroids or tacrolimus ointment-treated skin. Conclusion: Active vitamin D3 ointments show potent anti-tumor effect on UVB-treated mouse skin. The active vitamin D3ointments might decrease the risk of UVB-induced skin tumors under phototherapy.