title: Components of a standardised olive leaf dry extract (Ph. Eur.) promote hypothiocyanite production by lactoperoxidase.
abstract: We investigated in vitro the ability of a standardised olive leaf dry extract (Ph. Eur.) (OLE) as well as of its single components to circumvent the hydrogen peroxide-induced inhibition of the hypothiocyanite-producing activity of lactoperoxidase (LPO). The rate of hypothiocyanite (⁻OSCN) formation by LPO was quantified by spectrophotometric detection of the oxidation of 5-thio-2-nitrobenzoic acid (TNB). By using excess hydrogen peroxide, we forced the accumulation of inactive enzymatic intermediates which are unable to promote the two-electronic oxidation of thiocyanate. Both OLE and certain extract components showed a strong LPO-reactivating effect. Thereby an o-hydroxyphenolic moiety emerged to be essential for a good reactivity with the inactive LPO redox states. This basic moiety is found in the main OLE components oleuropein, oleacein, hydroxytyrosol, caffeic acid as well as in different other constituents including the OLE flavone luteolin. As LPO is a key player in the humoral immune response, these results propose a new mode of action regarding the well-known bacteriostatic and anti-inflammatory properties of the leaf extract of Olea europaea L.
authors.affiliation: Translational Centre for Regenerative Medicine (TRM) Leipzig, Philipp-Rosenthal-Straße 55, 04103 Leipzig, Germany; Institute for Medical Physics and Biophysics, Medical Faculty, University of Leipzig, Härtelstraße 16 - 18, 04107 Leipzig, Germany. Electronic address: joerg.flemmig@medizin.uni-leipzig.de.
authors.forename: Jörg
authors.initials: J
authors.lastname: Flemmig
authors.affiliation: Institute for Medical Physics and Biophysics, Medical Faculty, University of Leipzig, Härtelstraße 16 - 18, 04107 Leipzig, Germany. Electronic address: dr.rusch@googlemail.com.
authors.forename: Dorothea
authors.initials: D
authors.lastname: Rusch
authors.affiliation: Department of Pharmacognosy and Molecular Basis of Phytotherapy, Faculty of Pharmacy, Medical University of Warsaw, Bancha Street 1, 02097 Warsaw, Poland. Electronic address: monika.czerwinska@wum.edu.pl.
authors.forename: Monika Ewa
authors.initials: ME
authors.lastname: Czerwińska
authors.affiliation: Department of Pharmaceutical Biology, University of Leipzig, Johannisallee 21 - 23, 04103 Leipzig, Germany. Electronic address: rauwald@rz.uni-leipzig.de.
authors.forename: Hans-Wilhelm
authors.initials: HW
authors.lastname: Rauwald
authors.affiliation: Institute for Medical Physics and Biophysics, Medical Faculty, University of Leipzig, Härtelstraße 16 - 18, 04107 Leipzig, Germany. Electronic address: juergen.arnhold@medizin.uni-leipzig.de.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Arnhold
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D007784:Lactoperoxidase / Q000378:metabolism*; D031658:Olea / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D013861:Thiocyanates / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D000893:Anti-Inflammatory Agents; D010936:Plant Extracts; D013861:Thiocyanates; C014607:hypothiocyanite ion; D007784:Lactoperoxidase
keywords: Hydroxytyrosol; Lactoperoxidase; Olea europaea; Olive leaf dry extract; Phenolic components