Inhibitory Effect of Poria cocos on 12-O-Tetradecanoylphorbol-13-Acetate-Induced Ear Oedema and Tumour Promotion in Mouse Skin

The methanol extract from the sclerotium of Poria cocos was found to inhibit 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced tumour promotion in two-stage carcinogenesis in mouse skin. From the active fraction of the extract, eight lanostane-type triterpene acids and four 3,4-secolanostane-type triterpene acids were isolated. The isolated compounds showed inhibitory activity against TPA-induced ear inflammatory oedema. The 50% inhibitory dose of pachymic acid, 3-O-acetyl-16α-hydroxytrametenolic acid, dehydropachymic acid, dehydroeburiconic acid, 3β-hydroxylanosta-7,9(11),24-trien-21-oic acid, poricoic acid A and poricoic acid B for TPA-induced inflammation was 17–44 μg/ear, at a grade corresponding to that of hydrocortisone.