Prenylated flavanone derivatives isolated from Erythrina addisoniae are potent inducers of apoptotic cell death

NoExtracts of Erythrina addisoniae are frequently used in the traditional medicine of Western Africa, but insufficient information about active compounds is available. From the stem bark of E. addisoniae, three (1, 2, 4) and three known (3, 5, 6) flavanones were isolated: addisoniaflavanones I and II, containing either a 2″,3″-epoxyprenyl moiety (1) or a 2″,3″-dihydroxyprenyl moiety (2) were shown to be highly toxic (MTT assay: EC50 values of 5.25 ± 0.7 and 8.5 ± 1.3 μM, respectively) to H4IIE hepatoma cells. The cytotoxic potential of the other isolated flavanones was weaker (range of EC50 values between 15 and >100 μM). Toxic effects of addisoniaflavanone I and II were detectable after 3 h (MTT assay). Both compounds induced an apoptotic cell death (caspase-3/7 activation, nuclear fragmentation) in the hepatoma cells and, at high concentrations, also necrosis (membrane disruption: ethidium bromide staining). Formation of DNA strand breaks was not detectable after incubation with these compounds (comet assay). In conclusion, the prenylated flavanones addisoniaflavanones I and II may be of interest for pharmacological purposes due to their high cytotoxic and pro-apoptotic potential against hepatoma cells

The peroxisome: still a mysterious organelle

More than half a century of research on peroxisomes has revealed unique features of this ubiquitous subcellular organelle, which have often been in disagreement with existing dogmas in cell biology. About 50 peroxisomal enzymes have so far been identified, which contribute to several crucial metabolic processes such as β-oxidation of fatty acids, biosynthesis of ether phospholipids and metabolism of reactive oxygen species, and render peroxisomes indispensable for human health and development. It became obvious that peroxisomes are highly dynamic organelles that rapidly assemble, multiply and degrade in response to metabolic needs. However, many aspects of peroxisome biology are still mysterious. This review addresses recent exciting discoveries on the biogenesis, formation and degradation of peroxisomes, on peroxisomal dynamics and division, as well as on the interaction and cross talk of peroxisomes with other subcellular compartments. Furthermore, recent advances on the role of peroxisomes in medicine and in the identification of novel peroxisomal proteins are discussed

Antiplasmodial activities and cytotoxic effects of aqueous extracts and sesquiterpene lactones from Neurolaena lobata

Aqueous and lipophilic extracts of Neurolaena lobata (Asteraceae), obtained from Guatemala, were tested against Plasmodium falciparum in vitro. Moreover, sesquiterpene lactones, of the germacranolide and furanoheliangolide type, isolated from N. lobata, were shown to be active against P. falciparum in vitro. In addition to their antiplasmodial activity, their cytotoxic effects on human carcinoma cell lines were evaluated. Structure-activity relationships are discussed

Antiplasmodial activities and cytotoxic effects of aqueous extracts and sesquiterpene lactones from Neurolaena lobata

Aqueous and lipophilic extracts of Neurolaena lobata (Asteraceae), obtained from Guatemala, were tested against Plasmodium falciparum in vitro. Moreover, sesquiterpene lactones, of the germacranolide and furanoheliangolide type, isolated from N. lobata, were shown to be active against P. falciparum in vitro. In addition to their antiplasmodial activity, their cytotoxic effects on human carcinoma cell lines were evaluated. Structure-activity relationships are discussed