The Influence of Compounds from Selected Higher Plant Taxons on Platelet Aggregation

Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department: Pharmaceutical Botany and Ecology Candidate: Mgr. Eliška ŠTEJNAROVÁ Supervisor: Doc. RNDr. Lubomír OPLETAL, CSc. Title of doctoral thesis: The Influence of Compounds from Selected Higher Plant Taxons on Platelet Aggregation As a part of phytochemical study of secondary metabolites of plants from family Asteraceae, 32 species from this taxonomical unit were tested for platelet aggregation and antioxidant activity. Platelet aggregation was evaluated in vitro on human thrombocytes in platelet rich plasma. The primary used concentration of extracts was 500 µg·mL-1 , arachidonic acid (AA), adenosine diphosphate (ADP), collagen (COL), and thrombin (TR) were used as agonists. Out of the tested species, Leuzea carthamoides (leaves) was the only species which exhibited antiplatelet activity, the extract inhibited platelet aggregation induced by ADP and COL by 33 ± 6 % and 95 ± 5 %, respectively. None of the tested taxons showed proaggregatory effect. From 10.5 kg of dried leaves of L. carthamoide the extracts were prepared sequentially; five compounds: LC-1 (cynaropicrine), LC-2 (chlorojanerin), LC-3 (repdiolid), LC-4 (jaceosidin), LC-5 (hispidulin) were isolated from the most active extract (chloroform) by column and thin layer..