Anti-tumor promoting activity of bufadienolides from Kalanchoe pinnata and K. daigremontiana x tubiflora.
Five bufadienolides (1-5) isolated from the leaves of Kalanchoe pinnata and K. daigremontiana x tubiflora (Crassulaceae) were examined for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation in Raji cells induced by the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate. All bufadienolides showed inhibitory activity, and bryophyllin A (1) exhibited the most marked inhibition (IC50 = 0.4 microM) among the tested compounds. Bryophyllin C (2), a reduction analogue of 1, and bersaldegenin-3-acetate (3) lacking the orthoacetate moiety were less active. These results strongly suggest that bufadienolides are potential cancer chemopreventive agents.
Supratman
U
U
Division of Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, Osaka Prefecture University, Sakai, Japan.
Fujita
T
T
Akiyama
K
K
Hayashi
H
H
Murakami
A
A
Sakai
H
H
Koshimizu
K
K
Ohigashi
H
H
D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D000956:Antigens, Viral / Q000378:metabolism; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D002018:Bufanolides / Q000494:pharmacology*; D004354:Drug Screening Assays, Antitumor; D004854:Herpesvirus 4, Human / Q000235:genetics; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D014407:Tumor Cells, Cultured
D016588:Anticarcinogenic Agents; D000956:Antigens, Viral; D000972:Antineoplastic Agents, Phytogenic; D002018:Bufanolides