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.

No abstract

An investigation of the polar glycosidic fraction from the leaves of myrtle afforded four galloylated nonprenylated phloroglucinol glucosides (3a-d) related to the endoperoxide hormone G3 (4) in terms of structure and biogenesis. Despite their close similarity, significant antibacterial activity was shown only by one of these compounds (3b, gallomyrtucommulone B), while the G3 hormone (4) was inactive.

Investigation of an acetone extract from Asafetida afforded two drimane sesquiterpene dienones (fetidones A and B, 1a,b) and several known sesquiterpene coumarin ethers, one of which (8-acetoxy-5-hydroxyumbelliprenin, 2a) showed potent and specific NF-kappaB-inhibiting properties. This, coupled to a negligible cytotoxicity, qualifies 2a as a new anti-inflammatory chemotype, and its occurrence in asafetida might rationalize the use of this gum resin to alleviate and prevent colon inflammatory disturbances.

No abstract