title: Myrtucommulone from Myrtus communis induces apoptosis in cancer cells via the mitochondrial pathway involving caspase-9.
abstract: Myrtucommulone (MC) is a unique, nonprenylated acylphloroglucinol contained in the leaves of myrtle (Myrtus communis). Here, we addressed the potential of MC to induce apoptosis of cancer cells. MC potently induced cell death of different cancer cell lines (EC(50) 3-8 microM) with characteristics of apoptosis, visualized by the activation of caspase-3, -8 and -9, cleavage of poly(ADP-ribose)polymerase (PARP), release of nucleosomes into the cytosol, and DNA fragmentation. MC was much less cytotoxic for non-transformed human peripheral blood mononuclear cells (PBMC) or foreskin fibroblasts (EC(50) cell death = 20-50 microM), and MC up to 30 microM hardly caused processing of PARP, caspase-3, -8 and -9 in human PBMC. MC-induced apoptosis was mediated by the intrinsic rather than the extrinsic death pathway. Thus, MC caused loss of the mitochondrial membrane potential in MM6 cells and evoked release of cytochrome c from mitochondria. Interestingly, Jurkat cells deficient in caspase-9 were resistant to MC-induced cell death and no processing of PARP or caspase-8 was evident. In cell lines deficient in either CD95 (Fas, APO-1) signalling, FADD or caspase-8, MC was still able to potently induce cell death and PARP cleavage. Conclusively, MC induces apoptosis in cancer cell lines, with marginal cytotoxicity for non-transformed cells, via the mitochondrial cytochrome c/Apaf-1/caspase-9 pathway.
authors.affiliation: Institute of Pharmaceutical Chemistry, University of Frankfurt, Max-von-Laue Strasse 9, Frankfurt am Main, Germany.
authors.forename: Irina
authors.initials: I
authors.lastname: Tretiakova
authors.forename: Dagmar
authors.initials: D
authors.lastname: Blaesius
authors.forename: Lucia
authors.initials: L
authors.lastname: Maxia
authors.forename: Sebastian
authors.initials: S
authors.lastname: Wesselborg
authors.forename: Klaus
authors.initials: K
authors.lastname: Schulze-Osthoff
authors.forename: Jindrich
authors.initials: J
authors.lastname: Cinatl
authors.forename: Martin
authors.initials: M
authors.lastname: Michaelis
authors.forename: Oliver
authors.initials: O
authors.lastname: Werz
mesh_terms: D017209:Apoptosis; D053453:Caspase 9 / Q000378:metabolism*; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D045304:Cytochromes c / Q000378:metabolism; D053938:DNA Fragmentation / Q000187:drug effects; D018922:HL-60 Cells; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000378:metabolism*; D009707:Nucleosomes / Q000187:drug effects / Q000378:metabolism; D010696:Phloroglucinol / Q000031:analogs & derivatives* / Q000494:pharmacology; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism
chemical_list: D009707:Nucleosomes; C455139:myrtucommulone A; D045304:Cytochromes c; D010696:Phloroglucinol; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D053453:Caspase 9; D020169:Caspases