title: Some lupane-type triterpenes inhibit tumor promotion by 12-O-tetradecanoylphorbol-13-acetate in two-stage carcinogenesis in mouse skin.
abstract: We have found that several lupane-type triterpenes, including lupeol, its acetate, betulin and betulinic acid, inhibit 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation, and that betulinic acid inhibits tumor promotion in two-stage carcinogenesis in mice. Among seven lupane-type triterpenes assayed, these compounds inhibited the inflammatory activity induced by TPA in mice. The 50 % inhibitory dose of these compounds for TPA-induced inflammation was 0.4-4.0 μmol. Furthermore, topical application of lupeol, lupeol 3-acetate and betulin markedly suppressed the tumor-promoting effect of TPA (1 μg/mouse) in mouse skin initiated with 7,12-dimethyl-benz[a]anthracene (50 μg/mouse), at a grade corresponding to that of betulinic acid.
authors.affiliation: College of Pharmacy, Nihon University, 7-7-1, Narashinodai, Funabashi-shi, Chiba 274, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yasukawa
authors.forename: S
authors.initials: S
authors.lastname: Yu
authors.forename: S
authors.initials: S
authors.lastname: Yamanouchi
authors.forename: M
authors.initials: M
authors.lastname: Takido
authors.forename: T
authors.initials: T
authors.lastname: Akihisa
authors.forename: T
authors.initials: T
authors.lastname: Tamura