title: Sesquiterpene lactones from Lychnophora pohlii: neutrophil chemiluminescence inhibition and free radical scavenger activity.
abstract: Excessive production of reactive oxygen species (ROS) by polymorphonuclear leucocytes (PMNLs) is thought to contribute to the pathology of many inflammatory diseases. Sesquiterpene lactones (STLs) seem to be important contributors to the anti-inflammatory activity of many species of Lychnophora (Asteraceae), which have been widely used in Brazilian folk medicine because of this pharmacological property. In this study, the inhibitory effects of three STLs isolated from Lychnophora pohlii (lychnopholide, centratherin and goyazensolide) on rabbit PMNL oxidative burst were evaluated by the luminol-enhanced chemiluminescence (CL-lum) assay. All STLs tested showed concentration-dependent inhibitory activity on CL-lum but were not cytotoxic to PMNLs (evaluated by lactate dehydrogenase release) under the assessed conditions. Moreover, goyazensolide, the most active STL, had no free radical scavenger property, as assessed by 1,1-diphenyl-2picrylhydrazyl radical assay, and had no inhibitory effect on the luminol-horseradish peroxidase-hydrogen peroxide chemiluminescence. Taken together, the results of this investigation suggest that the concomitant presence of methacrylate ester and hydroxyl groups contributes to a high inhibitory effect on PMNL oxidative metabolism. This effect was not mediated by free radical scavenger or cytotoxic effects, but probably by inhibition of enzymes involved in the signal transduction pathways of the ROS generation process.
authors.affiliation: Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto da Universidade de São Paulo, Av. do Café s/n, 14040-903, Ribeirão Preto - SP, Brasil.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Kanashiro
authors.forename: Luciana M
authors.initials: LM
authors.lastname: Kabeya
authors.forename: Cristiane F F
authors.initials: CF
authors.lastname: Grael
authors.forename: Christiane O
authors.initials: CO
authors.lastname: Jordão
authors.forename: Ana Elisa C S
authors.initials: AE
authors.lastname: Azzolini
authors.forename: João Luis C
authors.initials: JL
authors.lastname: Lopes
authors.forename: Yara M
authors.initials: YM
authors.lastname: Lucisano-Valim
mesh_terms: D000818:Animals; D019659:Asteraceae / Q000737:chemistry*; D005260:Female; D016166:Free Radical Scavengers / Q000494:pharmacology*; D007783:Lactones / Q000494:pharmacology*; D008163:Luminescent Measurements; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D010084:Oxidation-Reduction; D011817:Rabbits; D017382:Reactive Oxygen Species; D012717:Sesquiterpenes / Q000494:pharmacology*
chemical_list: D016166:Free Radical Scavengers; D007783:Lactones; D017382:Reactive Oxygen Species; D012717:Sesquiterpenes