Anti-tumor-promoting activity of majonoside-R2 from Vietnamese ginseng, Panax vietnamensis Ha et Grushv. (I).
Seven saponins (1-7) isolated from the rhizomes and roots of Panax vietnamensis were tested for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) induced by the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), in Raji cells as a primary screening test for anti-tumor-promoters (cancer chemopreventive agents). The ocotillol-type saponin, majonoside-R2 (2), which is the major and characteristic constituent of this plant, exhibited a significant inhibitory effect on EBV-EA activation. Furthermore, the cell cycle analysis of 2 on Raji cells was also examined and strong inhibition was observed on the effect of the cell cycle induced by TPA. Compound 2 showed potent anti-tumor-promoting activity in two-stage carcinogenesis tests of mouse skin using 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and TPA or fumonisin B1 as a promoter. Consequently, these results suggest that majonoside-R2 (2) could be a valuable chemopreventive agent against chemical carcinogenesis.
Konoshima
T
T
Kyoto Pharmaceutical University, Japan.
Takasaki
M
M
Tokuda
H
H
Nishino
H
H
Duc
N M
NM
Kasai
R
R
Yamasaki
K
K
D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D000956:Antigens, Viral / Q000187:drug effects; D002264:Carboxylic Acids / Q000037:antagonists & inhibitors; D037341:Fumonisins; D036145:Ginsenosides; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010212:Papilloma / Q000517:prevention & control; D012503:Saponins / Q000494:pharmacology*; D012878:Skin Neoplasms / Q000517:prevention & control; D013755:Tetradecanoylphorbol Acetate / Q000037:antagonists & inhibitors
D016588:Anticarcinogenic Agents; D000956:Antigens, Viral; D002264:Carboxylic Acids; C033305:Epstein-Barr virus early antigen; D037341:Fumonisins; D036145:Ginsenosides; D012503:Saponins; C056933:fumonisin B1; C098043:majonoside R2; D013755:Tetradecanoylphorbol Acetate