title: The in vitro effects of Hypericum species on human leukocyte myeloperoxidase activity.
abstract: Myeloperoxidase (MPO) is a major component of the antimicrobial system of polymorphonuclear neutrophils. The heme enzyme MPO catalyzes the conversion of hydrogen peroxide and chloride to hypochlorous acid. Hypochlorous acid is the major strong oxidant produced by neutrophils and may contribute to inflammatory tissue damage. It was reported that certain antiinflammatory drugs are capable of inhibiting MPO activity and this inhibition may account for their antiinflammatory effect. Hypericum L. is a genus of about 400 species, widespread throughout the world. Some species of genus exhibit a significant antiinflammatory activity beside their several pharmacological properties such as antidepressant, diuretic, antihelmintic, and antibacterial. In this study, we investigated the in vitro effects of three Hypericum species, which exhibit antiinflammatory activity, on human polymorphonuclear leukocyte MPO activity. We found that each extract of Hypericum species reduced the peroxidative and chlorinating activity of human leukocyte MPO in concentration-dependent manner. The antiinflammatory activity of these species may be related with inhibition of MPO activity.
authors.affiliation: Department of Biochemistry, Faculty of Pharmacy, Ege University, Bornova, 35100 Izmir, Turkey. papuccuoglua@pharm.ege.edu.tr
authors.forename: Aysun
authors.initials: A
authors.lastname: Pabuçcuoğlu
authors.forename: Sibel
authors.initials: S
authors.lastname: Konyalioğlu
authors.forename: Meral
authors.initials: M
authors.lastname: Baş
authors.forename: Gözde Elgin
authors.initials: GE
authors.lastname: Meral
mesh_terms: D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D006801:Humans; D020902:Hypericum / Q000737:chemistry*; D066298:In Vitro Techniques; D007962:Leukocytes / Q000187:drug effects* / Q000201:enzymology; D009195:Peroxidase / Q000378:metabolism*; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000494:pharmacology; D013045:Species Specificity
chemical_list: D000893:Anti-Inflammatory Agents; D010936:Plant Extracts; D009195:Peroxidase