title: Polyphenols from Silybum marianum inhibit in vitro the oxidant response of equine neutrophils and myeloperoxidase activity.
abstract: A recent study showed that silymarin, a standardized extract of S. marianum might be used in the prevention of equine laminitis. We investigated the effects of quercetin and some compounds found in silymarin (silybin, taxifolin and dehydrosilybin) on reactive oxygen species (ROS) production and myeloperoxidase (MPO) release by stimulated equine neutrophils (PMNs) and on MPO activity. All compounds (tested between 100 nm and 100 μm) inhibited superoxide anion production by stimulated PMNs in a dose-dependent manner. Dehydrosilybin and quercetin inhibited superoxide production and MPO release from 10 μm. Classical MPO assay showed quercetin as the most potent inhibitor, followed by taxifolin, dehydrosilybin and silybin. SIEFED MPO assay highlighting the binding of tested compounds to MPO showed that only quercetin and taxifolin maintained an efficient inhibition above 90% at 10 μm. Altogether, our results showed a strong inhibition of PMN activation by planar compounds such as quercetin and dehydrosilybin and a strong inhibition of MPO activity by the smallest molecules, quercetin and taxifolin. In conclusion, the compounds from silymarin may be useful for modulating the oxidative response of PMNs, involved in the pathogenesis of laminitis, but further in vivo studies are needed.
authors.affiliation: Department of Medical Chemistry & Biochemistry, Faculty of Medicine and Dentistry, Palacky University, Olomouc, Czech Republic.
authors.forename: A
authors.initials: A
authors.lastname: Zholobenko
authors.affiliation: Centre for Oxygen, R&D (CORD), Institut de Chimie, Université de Liège, Liège, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: Mouithys-Mickalad
authors.affiliation: Department of Medical Chemistry & Biochemistry, Faculty of Medicine and Dentistry, Palacky University, Olomouc, Czech Republic.
authors.forename: M
authors.initials: M
authors.lastname: Modriansky
authors.affiliation: Centre for Oxygen, R&D (CORD), Institut de Chimie, Université de Liège, Liège, Belgium.|Faculty of Veterinary Medicine, Université de Liège, Liège, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Serteyn
authors.affiliation: Centre for Oxygen, R&D (CORD), Institut de Chimie, Université de Liège, Liège, Belgium. t.franck@ulg.ac.be.|Faculty of Veterinary Medicine, Université de Liège, Liège, Belgium. t.franck@ulg.ac.be.
authors.forename: T
authors.initials: T
authors.lastname: Franck
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D006736:Horses; D020944:Silybum marianum / Q000737:chemistry*; D015394:Molecular Structure; D009504:Neutrophils / Q000187:drug effects*; D018384:Oxidative Stress; D009195:Peroxidase / Q000037:antagonists & inhibitors*; D059808:Polyphenols / Q000737:chemistry / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000975:Antioxidants; D059808:Polyphenols; D017382:Reactive Oxygen Species; D009195:Peroxidase