title: Antiplatelet and antithrombotic activities of timosaponin B-II, an extract of Anemarrhena asphodeloides.
abstract: 1. Antithrombotic agents are effective in the treatment of ischaemic stroke. Timosaponin B-II (TB-II) is a major active component of Anemarrhena asphodeloides Bunge (Liliaceae; rhizome) that has protective effects against cerebral ischaemic damage. The present study examined the antiplatelet and antithrombotic actions of TB-II. 2. In in vitro experiments, TB-II (20, 40 and 80 mg/mL) potently and dose-dependently inhibited ADP-induced platelet aggregation. Furthermore, 1, 3 and 6 mg/kg TB-II prolonged activated partial thromboplastin time by 9.29, 16.86 and 25.50%, respectively, but had no effect on the prothrombin time. Furthermore, 1, 3 and 6 mg/kg TB-II significantly reduced the wet weight, dry weight and length of the thrombi (%inhibition (based on wet weight): 13.6, 19.8 and 24.7%, respectively). 3. In a rabbit arteriovenous shunt model, 1, 3 and 6 mg/kg, i.v., TB-II had no effect on thrombus formation. Plasma euglobulin lysis time and fibrin degradation product were not affected by 1, 3 and 6 mg/kg TB-II, but plasminogen levels were decreased significantly by 14.4, 18.3 and 29.0%, respectively. 4. The results of the present study demonstrate significant antiplatelet and anticoagulation effects of TB-II and suggest that these actions could contribute to its neuroprotective effect against damage following cerebral ischaemia damage.
authors.affiliation: Department of Pharmacy, Changzheng Hospital, Shanghai, China.
authors.forename: Wen-Quan
authors.initials: WQ
authors.lastname: Lu
authors.forename: Yan
authors.initials: Y
authors.lastname: Qiu
authors.forename: Tie-Jun
authors.initials: TJ
authors.lastname: Li
authors.forename: Xia
authors.initials: X
authors.lastname: Tao
authors.forename: Lian-Na
authors.initials: LN
authors.lastname: Sun
authors.forename: Wan-Sheng
authors.initials: WS
authors.lastname: Chen
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D031403:Anemarrhena / Q000737:chemistry*; D000818:Animals; D000925:Anticoagulants / Q000494:pharmacology; D001777:Blood Coagulation / Q000187:drug effects; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism; D005343:Fibrinolytic Agents / Q000494:pharmacology*; D010314:Partial Thromboplastin Time; D010958:Plasminogen / Q000037:antagonists & inhibitors / Q000378:metabolism; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D011516:Prothrombin / Q000378:metabolism; D011517:Prothrombin Time; D011817:Rabbits; D012503:Saponins / Q000494:pharmacology*; D012712:Serum Globulins / Q000378:metabolism; D013256:Steroids / Q000494:pharmacology*; D013927:Thrombosis / Q000188:drug therapy
chemical_list: D000925:Anticoagulants; D005338:Fibrin Fibrinogen Degradation Products; D005343:Fibrinolytic Agents; D010975:Platelet Aggregation Inhibitors; D012503:Saponins; D012712:Serum Globulins; D013256:Steroids; C523027:timosaponin B-II; D000244:Adenosine Diphosphate; D011516:Prothrombin; D010958:Plasminogen