Effect of chemical constituents from plants on 12-O-tetradecanoylphorbol-13-acetate-induced inflammation in mice.

The induction of edema in the mouse ear has been established as a reliable in vivo assay for tumor promoters. Therefore, inhibitors of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear edema are most likely to be inhibitors of skin tumor promotion. Besides the application for this assay for the screening of compounds, it also allows comparison of the activities of groups of related compounds such as flavonoids. Results obtained in this way showed that the double bond at C-2 and C-3 of the flavonoid structure is a prerequisite for anti-tumor-promoting activity, and indicated that activity in this screening assay for inhibitors of TPA-induced ear edema reflects the anti-tumor-promoting effect in two-stage carcinogenesis.