title: Extract of a spice--omum (Trachyspermum ammi)-shows antiaggregatory effects and alters arachidonic acid metabolism in human platelets.
abstract: An ethereal extract of omum (Trachyspermum ammi; Hindustani: ajwan)--a frequently consumed spice--was found to inhibit platelet aggregation induced by arachidonic acid (AA), epinephrine and collagen; in this respect it was most effective against AA-induced aggregation. Inhibition of aggregation by omum could be explained by its effect on platelet thromboxane production as suggested by the following experimental observation. (i) Omum reduced TxB2 formation in intact platelet preparations from added arachidonate, and (ii) it reduced the formation of TxB2 from AA-labelled platelets after stimulation with Ca2+-ionophore A23187 by a direct action on cyclooxygenase as it did not affect the release of AA from labelled platelets. An increased formation of lipoxygenase-derived products from exogenous AA in omum-treated platelets was apparently due to redirection of AA from cyclooxygenase to the lipoxygenase pathway.
mesh_terms: D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000037:antagonists & inhibitors / Q000097:blood* / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects*; D000001:Calcimycin / Q000494:pharmacology; D002855:Chromatography, Thin Layer; D003094:Collagen / Q000037:antagonists & inhibitors / Q000494:pharmacology; D003212:Condiments; D004837:Epinephrine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000097:blood; D066298:In Vitro Techniques; D010743:Phospholipids / Q000097:blood; D010936:Plant Extracts / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects*; D013929:Thromboxane B2 / Q000097:blood
chemical_list: D001095:Arachidonic Acids; D006893:Hydroxyeicosatetraenoic Acids; D010743:Phospholipids; D010936:Plant Extracts; D016718:Arachidonic Acid; D000001:Calcimycin; D013929:Thromboxane B2; D003094:Collagen; D004837:Epinephrine