The effects of topical application of geniposide on 12-o-tetra-decanoylphorbol-13-acetate (TPA)-induced promotion of skin tumors, hyperplasia, ornithine decarboxylase (ODC) and inflammation were evaluated in female CD-1 mice. Topical application of geniposide (0.2 or 1.0.mu.mol) with TPA (15nmol) twice weekly for 20 weeks to mice previously initiated with benzo[a] pyrene (B[a]P) inhibited the number of TPA-induced tumors per mouse by 84 or 89%, respectively. Pre-application of the same amount of geniposide also afforded significant protection against TPA-induced hyperplasia in the ear skin. Topical application of geniposide inhibited tumor promoter-caused induction of epidermal ODC activity by TPA (5nmol). The topical application of geniposide (0.2 or 1.0.mu.mol) inhibited TPA-induced edema of mouse ears by 41 or 43%, respectively. Pretreatment of mouse skin with various amounts of geniposide caused inhibition of hydrogen peroxide (H/sub 2/O/sub 2/) and myeloperoxidase (MPO) formation by TPA. These results indicate that geniposide possesses potential as a cancer chemopreventive agent against tumor promotion.
