Cancer chemopreventive agents (antitumor-promoters) from Ajuga decumbens. |
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| Authors: | M Takasaki H Tokuda H Nishino T Konoshima |
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| Affiliation: | Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto 607-8414, and Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto 602-0841, Japan. |
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| Abstract: | Sixteen compounds (1-16) isolated from the flowering whole plant of Ajuga decumbens have been tested for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) induction by the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), as a primary screening test for antitumor-promoters (potential cancer chemopreventive agents). Five compounds (6, 9, and 12-14) showed strong inhibitory effects on EBV-EA induction. Of these active compounds, two major constituents of this plant, cyasterone (6) and 8-acetylharpagide (13), showed potent antitumor-promoting activities on a mouse-skin in vivo two-stage carcinogenesis procedure, using 7, 12-dimethylbenz[a]anthracene as initiator and TPA as promoter. Further, compound 13 also exhibited potent chemopreventive activity in a mouse pulmonary tumor model. |
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