Inhibitory Effects of Lanostane-Type Triterpene Acids, the Components of <i>Poria cocos</i>, on Tumor Promotion by 12-O-Tetradecanoylphorbol-13-Acetate in Two-Stage Carcinogenesis in Mouse Skin

Pachymic acid, 3-O-acetyl-16 Α-hydroxytrametenolic acid, and poricoic acid B had been isolated from the sclerotium of Poria cocos Wolf. These compounds showed a strong inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate-induced inflammation in mice. At 0.2 µmol/mouse, these compounds markedly inhibited the promoting effect of 12-O-tetradecanoylphorbol-13-acetate (1 µg/mouse) on skin tumor formation following initiation with 7,12-dimethylbenz[a]anthracene (50 µg/mouse).