Inhibitory effect of taraxastane-type triterpenes on tumor promotion by 12-O-tetradecanoylphorbol-13-acetate in two-stage carcinogenesis in mouse skin.

Two taraxastane-type hydroxy triterpenes, taraxasterol and faradiol, isolated from the flowers of Compositae plants Cynara scolymus (artichoke) and Chrysanthemum morifilolium (chrysanthemum), respectively, showed strong inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation in mice. At 2.0 mumol/mouse, these compounds inhibited markedly the tumor-promoting effect of TPA (1 microgram/mouse) on skin tumor formation following initiation with 7,12-dimethylbenz[alpha]anthracene (50 micrograms/mouse).