title: Antioxidant and antiaggregatory effects of an extract from Conyza canadensis on blood platelets in vitro.
abstract: The antioxidative activity of the polysaccharide extract from Conyza canadensis in blood platelets treated with peroxynitrite (ONOO-) was studied. Peroxynitrite as a strong biological oxidant has toxic effects on blood platelets and induces the oxidation of thiols, carbonylation and nitration of platelet proteins and lipid peroxidation. Therefore, the aim of our study was to assess if the natural extract from herbal plant, Conyza Canadensis, may protect platelet proteins against nitrative and oxidative damage induced by ONOO-. In our study we measured oxidative damage of platelet proteins induced by peroxynitrite and protectory effects of this extract by estimation of the level of carbonyl groups and nitrotyrosine (a marker of platelet protein nitration). We also used cytochrome c reduction method to test the ability of this extract to change O2-* generation in platelets. Moreover, we determined the effects of the extract on blood platelet aggregation induced by ADP. We observed that the extract from Conyza canadensis distinctly reduced oxidation and nitration of proteins in blood platelets treated with ONOO-(0.1mM) and O2-* production in these cells. The extract from Conyza canadensis also inhibited platelet aggregation. The ability of the extract to decrease O2-* generation in blood platelets supports the importance of free radicals in platelet functions, including aggregation process. The present study suggests that the natural polysaccharide extract from Conyza canadensis has antiaggregatory and antioxidative activities, and therefore may be beneficial in the prevention of peroxynitrite-related diseases, such as cardiovascular or inflammatory diseases.
authors.affiliation: Department of General Biochemistry, Institute of Biochemistry, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland. olasb@biol.uni.lodz.pl
authors.forename: Beata
authors.initials: B
authors.lastname: Olas
authors.forename: Joanna
authors.initials: J
authors.lastname: Saluk-Juszczak
authors.forename: Izabela
authors.initials: I
authors.lastname: Pawlaczyk
authors.forename: Pawel
authors.initials: P
authors.lastname: Nowak
authors.forename: Joanna
authors.initials: J
authors.lastname: Kolodziejczyk
authors.forename: Roman
authors.initials: R
authors.lastname: Gancarz
authors.forename: Barbara
authors.initials: B
authors.lastname: Wachowicz
mesh_terms: D000704:Analysis of Variance; D000975:Antioxidants / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects*; D035401:Conyza / Q000737:chemistry*; D006801:Humans; D066298:In Vitro Techniques; D018384:Oxidative Stress / Q000187:drug effects*; D030421:Peroxynitrous Acid / Q000009:adverse effects; D010936:Plant Extracts / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects*; D050050:Protein Carbonylation / Q000187:drug effects; D014443:Tyrosine / Q000031:analogs & derivatives / Q000187:drug effects
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D030421:Peroxynitrous Acid; C002744:3-nitrotyrosine; D014443:Tyrosine