Achyranthoside H methyl ester, a novel oleanolic acid saponin derivative from Achyranthes fauriei roots, induces apoptosis in human breast cancer MCF-7 and MDA-MB-453 cells via a caspase activation pathway.
Achyranthoside H methyl ester (AH-Me) is an oleanolic acid saponin derivative isolated from the roots of Achyranthes fauriei through diazomethane treatment. AH-Me exhibited significant cytotoxicity against human breast cancer MCF-7 and MDA-MB-453 cells, with respective ID(50) values of 4.0 and 6.5 muM: in the MTT assay. AH-Me is a unique saponin containing three methoxycarbonyl groups in the sugar moiety linked to the C-3 position of oleanolic acid. The demethylation of these methoxycarbonyl groups by alkaline hydrolysis caused a marked reduction of the cytotoxicity of AH-Me, suggesting that the methoxycarbonyl groups of AH-Me are key groups for the acquisition of cytotoxicity against human cancer cells. The staining of cancer cells with 4',6'-diamidino-2-phenylindole (DAPI) showed that the population of cells with altered nuclear morphology, for example chromatin condensation and fragmentation, increased markedly after AH-Me treatment. Exposure of MCF-7 and MDA-MB-453 cells to AH-Me resulted in a dose-dependent and time-dependent increase in the sub-G1 population, and in the cleavage of poly-ADP-ribose polymerase (PARP) followed by the formation of an 89 kD peptide. Pretreatment of the cells with the pan-caspase inhibitor z-VAD-fmk abolished the cleavage of PARP by AH-Me treatment and suppressed the antiproliferative effect of AH-Me on tumor cell growth. These results together led to the suggestion that AH-Me induces apoptosis via the caspase activation pathway in human breast cancer cells, and apoptosis is the major mode of the cytotoxic effect triggered by AH-Me.
Fukumura
Motonori
M
School of Pharmaceutical Sciences, Showa University, Hatanodai 1-5-8, Shinagawa-ku, Tokyo, Japan.
Ando
Hidehiro
H
Hirai
Yasuaki
Y
Toriizuka
Kazuo
K
Ida
Yoshiteru
Y
Kuchino
Yoshiyuki
Y
D029044:Achyranthes / Q000737:chemistry*; D017209:Apoptosis / Q000187:drug effects; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D020169:Caspases / Q000187:drug effects* / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D004789:Enzyme Activation; D005260:Female; D020719:Glucuronides / Q000008:administration & dosage* / Q000737:chemistry / Q000302:isolation & purification; D006801:Humans; D006868:Hydrolysis; D020128:Inhibitory Concentration 50; D018517:Plant Roots; D011065:Poly(ADP-ribose) Polymerases / Q000187:drug effects / Q000378:metabolism; D012503:Saponins / Q000008:administration & dosage* / Q000737:chemistry / Q000302:isolation & purification; D013997:Time Factors
D020719:Glucuronides; D012503:Saponins; C529485:achyranthoside H; D011065:Poly(ADP-ribose) Polymerases; D020169:Caspases