Anti-tumor-promoting activity of diterpenes from Excoecaria agallocha.
To search for possible anti-tumor-promoters, we carried out the primary screening of seventeen diterpenes (1-17) isolated from the resinous wood of Excoecaria agallocha (Euphorbiaceae) using an in vitro synergistic assay system. Of these diterpenes, ent-16-hydroxy-3-oxo-13-epi-manoyloxide (5), (13R,14R)-ent-8alpha,13;14,15-diepoxy-13-epi- labda-3beta-ol (8) ent-3beta-hydroxy-15-beyeren-2-one (10) and ent-15-hydroxy-labda-8(17),13E-dien-3-one (14) exhibited significant inhibitory effects on Epstein-Barr virus (EBV) activation induced by the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). Furthermore, 10 exhibited remarkable anti-tumor-promoting activity in vivo on a two-stage carcinogenesis test of mouse tumor using 7,12-dimethylbenz[a]-anthracene (DMBA) as an initiator and TPA as a promoter.
Konishi
T
T
Kyoto Pharmaceutical University, Japan.
Takasaki
M
M
Tokuda
H
H
Kiyosawa
S
S
Konoshima
T
T
D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D000956:Antigens, Viral / Q000187:drug effects / Q000502:physiology; D002273:Carcinogens; D004224:Diterpenes / Q000494:pharmacology*; D019665:Euphorbiaceae / Q000737:chemistry*; D005260:Female; D006801:Humans; D051379:Mice; D008813:Mice, Inbred ICR; D010212:Papilloma / Q000139:chemically induced / Q000517:prevention & control; D012878:Skin Neoplasms / Q000139:chemically induced / Q000517:prevention & control; D013755:Tetradecanoylphorbol Acetate; D014775:Virus Activation / Q000187:drug effects
C116089:3-hydroxy-15-beyeren-2-one; D016588:Anticarcinogenic Agents; D000956:Antigens, Viral; D002273:Carcinogens; D004224:Diterpenes; C033305:Epstein-Barr virus early antigen; D015127:9,10-Dimethyl-1,2-benzanthracene; D013755:Tetradecanoylphorbol Acetate