Chemoprevention by alpha-santalol on UVB radiation-induced skin tumor development in mice.

Studies have shown the chemopreventive effects of alpha-santalol on chemically and UVB-induced skin cancer in mice. The objective of the present investigation was to find the lowest effective concentration of alpha-santalol for the chemopreventive effects on UVB-induced skin tumor development in mice and to determine antiperoxidant effect of alpha-santalol in order to elucidate its possible mechanism of action. Female SKH-1 mice were divided into different groups receiving either vehicle alone or different concentrations of alpha-santalol. Mice in all the groups were initiated and promoted with UVB radiation for skin tumor development. The promotion phase continued for 30 weeks. Skin tumors were counted once a week for 30 weeks. Lipid peroxidation was assayed in skin and liver microsomes by measuring malonaldehyde formed using thiobarbituric acid method. Topical administration of alpha-santalol reduced UVB-induced skin tumor development in a concentration-dependent manner. Application of alpha-santalol (5%) significantly (p < 0.05) delayed skin tumor development for 25 weeks and reduced tumor multiplicity. alpha-Santalol also inhibited in vitro lipid peroxidation in skin and liver microsomes. alpha-Santalol application prevents UVB-induced skin tumor development possibly by acting as an antiperoxidant.