Sesquiterpene lactones fromLychnophora 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.

Histolocalization of chemotaxonomic markers in Brazilian Vernonieae (Asteraceae)

“…It is well know that Lychnophorinae produce metabolites of therapeutic importance, such as terpenoids (mono‐, sesqui‐, di‐ and triterpenes and sesquiterpene lactones) and phenolic compounds (flavonoids and cinnamic acid derivatives) (Vichnewski & Gilbert, ; Vichnewski et al ., ; Herz et al ., ; Dias Barros et al ., ; Oliveira et al ., ; Grael et al ., ; Dos Santos et al ., ; Kanashiro et al ., ; Taleb‐Contini et al ., ; Silvério et al ., ; Keles et al ., ; Dos Santos et al ., ; Baldin et al ., ; De Souza et al ., ; Abreu et al ., ; Silvério et al ., ; Gouvea et al ., ; Saúde‐Guimarães, Raslan & Oliveira, ). In addition, many studies have investigated the chemotaxonomy of Lychnophorinae because of the chemical richness that characterizes the subtribe (Bohlmann et al ., , b; Herz et al ., ; Bohlmann et al ., ; Zdero et al ., ; Bohlmann et al ., ; Bohlmann & Jakupovic, ; Borella et al ., ; Lunardello et al ., ; Borella et al ., ; Vichnewski et al ., ; Sacilotto, Sartori & Vichnewski, ; Sartori et al ., ; Sakamoto et al ., , ; Keles et al ., ; Sakamoto et al ., ; Souza et al ., ; Lusa et al ., ).…”

Secondary chemistry and ribosomal DNA data congruencies in Arnica (Asteraceae)

“…Sesquiterpene lactones (STLs) constitute one of the largest groups of natural products known, with more than 5000 identified structures (Schmidt, 2006), of which most are found in Asteraceae. These compounds have been investigated for potential use as chemotaxonomic markers in the family as a whole, using cluster analyses, principal component analyses (PCA), or other multivariate statistical methods (e.g., Alvarenga et al., 2001; Hristozov et al., 2007), and have also been investigated as a source of bioactive compounds (Schmidt and Heilmann, 2002; Kanashiro et al., 2006; Wagner et al., 2006; Scotti et al., 2007).…”

4-Methylcoumarin Derivatives Inhibit Human Neutrophil Oxidative Metabolism and Elastase Activity

“…[6][7][8][9][10][11][12][13][14][15] In the present study, we assessed whether six coumarin derivatives inhibit the human neutrophil oxidative metabolism and elastase activity, and investigated some of the underlying mechanisms of action of these compounds.…”

“…1,2,4,5 Our research group has investigated the antioxidant and immunomodulatory activities of plant extracts [6][7][8] and isolated secondary metabolites like coumarins, [9][10][11] flavonoids, 7,[12][13][14] and sesquiterpene lactones. 15 We aim to discover prototypes of compounds that can modulate the effector functions of neutrophils and supplement the endogenous antioxidant defense system.…”