Anti-tumor-promoting activities of euglobals from Eucalyptus plants.
To search for possible anti-tumor-promoters (chemopreventive agents), we carried out a primary screening of 21 euglobals (acylphloroglucinol-monoterpene or -sesquiterpene structures) isolated from the juvenile leaves of five species of Eucalyptus plants using an in vitro synergistic assay system. Of these compounds, euglobal-G1--G5 (1-5), -Am-2 (15) and -III (16) exhibited significant inhibitory effects on Epstein-Barr virus (EBV) activation induced by the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). Furthermore, the effects of compounds 1 and 16 on the cell cycle of Raji cells were also examined by a flow cytometer, and both compounds 1 and 16 exhibited strong inhibition on the effect of the cell cycle induced by TPA. These two euglobals (1 and 16) exhibited remarkable anti-tumor-promoting effects on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test.
Takasaki
M
M
Kyoto Pharmaceutical University, Japan.
Konoshima
T
T
Kozuka
M
M
Tokuda
H
H
D015127:9,10-Dimethyl-1,2-benzanthracene / Q000633:toxicity; D000818:Animals; D016588:Anticarcinogenic Agents / Q000627:therapeutic use*; D000956:Antigens, Viral / Q000187:drug effects / Q000502:physiology; D002051:Burkitt Lymphoma / Q000821:virology; D002453:Cell Cycle / Q000187:drug effects; D003043:Cocarcinogenesis; D004354:Drug Screening Assays, Antitumor; D005052:Eucalyptus / Q000737:chemistry*; D005260:Female; D051379:Mice; D008813:Mice, Inbred ICR; D010212:Papilloma / Q000139:chemically induced / Q000517:prevention & control* / Q000821:virology; D010936:Plant Extracts / Q000627:therapeutic use*; D010946:Plants, Medicinal; D012878:Skin Neoplasms / Q000139:chemically induced / Q000517:prevention & control* / Q000821:virology; D013329:Structure-Activity Relationship; D013729:Terpenes / Q000627:therapeutic use*; D013755:Tetradecanoylphorbol Acetate / Q000633:toxicity; D014407:Tumor Cells, Cultured
D016588:Anticarcinogenic Agents; D000956:Antigens, Viral; C033305:Epstein-Barr virus early antigen; D010936:Plant Extracts; D013729:Terpenes; D015127:9,10-Dimethyl-1,2-benzanthracene; D013755:Tetradecanoylphorbol Acetate