title: Heptelidic acid, a sesquiterpene lactone, inhibits Etoposide-induced apoptosis in human leukemia U937 cells.
abstract: In the course of screening for substances that inhibit etoposide (10 microg/ml)-induced apoptosis in human leukemia U937 cells, fungal strain F000120, which exhibits potent inhibitory activity, was selected. The active compound was purified from an ethyl acetate extract of the microorganism by Sep-pak C18 column chromatography and HPLC, and was identified as heptelidic acid (koningic acid) by spectroscopic methods. This compound inhibited caspase- 3 induction in U937 cells with an IC(50) value of 40 microM after 8 h of etoposide treatment. Fluorescent dye staining with acridine orange and ethidium bromide showed that heptelidic acid inhibited apoptosis. Furthermore, it was found that DNA fragmentation and caspase-3 activation, the biological hallmarks of apoptosis, were inhibited by the compound in a dose-dependent manner, suggesting that heptelidic acid inhibits etoposide-induced apoptosis via downregulation of caspases.
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-70l, Korea.
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Choong Hwan
authors.initials: CH
authors.lastname: Lee
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D061945:Caspase Inhibitors; D053938:DNA Fragmentation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005047:Etoposide / Q000494:pharmacology*; D006801:Humans; D019636:Neurodegenerative Diseases / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology; D012717:Sesquiterpenes / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism; D014242:Trichoderma / Q000737:chemistry / Q000378:metabolism; D020298:U937 Cells
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D061945:Caspase Inhibitors; D012717:Sesquiterpenes; C027285:heptelidic acid; D005047:Etoposide; D053148:Caspase 3