title: The extract from hop cones (Humulus lupulus) as a modulator of oxidative stress in blood platelets.
abstract: The plant Humulus lupulus is known as the raw material of the brewing industry. Hop cones, rich in polyphenolic compounds and acyl phloroglucides, are widely used to preserve beer and to give it a characteristic aroma and flavor. Hop cones have long been used for medicinal purposes. In particular, hop preparations were mainly recommended for the treatment of sleeping disorders. The antioxidative action of hop cones, however, is poorly understood. The aim of our present study was to investigate in vitro changes in human blood platelets induced by peroxynitrite (ONOO(-), the compound of particular importance for vascular thrombosis and inflammatory process) in the presence of hop cone extract (Humulus lupulus). The antioxidative action of the extract was also compared with the properties of a well-characterized antioxidative commercial monomeric polyphenol, resveratrol (3,4',5-trihydroxystilbene) in a model system in vitro. Various biomarkers of oxidative/nitrative stress, such as carbonyl groups, 3-nitrotyrosine and thiobarbituric acid reactive substances (TBARS) were estimated. The 3-nitrotyrosine formation and carbonyl group generation was assessed by the use of a competition ELISA test and ELISA test, respectively. Tested plant extract (12.5-50 µg/ml), like resveratrol, significantly inhibited protein carbonylation and nitration in the blood platelets treated with ONOO(-) (0.1 mM). The extract from hop cones, like resveratrol, also caused a distinct reduction of platelet lipid peroxidation induced by ONOO(-). The present results indicate that the hope cone extract has in vitro protective effects against ONOO(-), such as induced oxidative/nitrative damage to the human platelet proteins and lipids. However, in comparative studies the extract was not found to be a more effective antioxidant than the solution of pure resveratrol.
authors.affiliation: Department of General Biochemistry, Institute of Biochemistry, University of Lodz, Poland. olasb@biol.uni.lodz.pl
authors.forename: Beata
authors.initials: B
authors.lastname: Olas
authors.forename: Joanna
authors.initials: J
authors.lastname: Kolodziejczyk
authors.forename: Barbara
authors.initials: B
authors.lastname: Wachowicz
authors.forename: Dariusz
authors.initials: D
authors.lastname: Jędrejek
authors.forename: Anna
authors.initials: A
authors.lastname: Stochmal
authors.forename: Wiesław
authors.initials: W
authors.lastname: Oleszek
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D001792:Blood Platelets / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D005419:Flavonoids / Q000494:pharmacology; D006801:Humans; D027582:Humulus / Q000737:chemistry*; D015227:Lipid Peroxidation / Q000187:drug effects; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D030421:Peroxynitrous Acid / Q000009:adverse effects / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D010636:Phenols / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D050050:Protein Carbonylation / Q000187:drug effects; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D014443:Tyrosine / Q000031:analogs & derivatives / Q000032:analysis
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D013267:Stilbenes; D017392:Thiobarbituric Acid Reactive Substances; D030421:Peroxynitrous Acid; C002744:3-nitrotyrosine; D014443:Tyrosine; D000077185:Resveratrol