Antiplatelet and antithrombotic activities of methanol extract of Usnea longissima

• Published in: Phytotherapy research Vol. 19; no. 12; pp. 1061 - 1064
• Main Authors: Lee, K.A, Kim, M.S
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.12.2005; Wiley
• Subjects: Animals; antiplatelet; antithrombosis; Biological and medical sciences; Bleeding Time; General pharmacology; lichen; Male; Medical sciences; Mice; Mice, Inbred ICR; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; Platelet Aggregation Inhibitors - therapeutic use; Rats; Rats, Sprague-Dawley; Thrombosis - drug therapy; Usnea - therapeutic use; Usnea longissima; Usnea longissima; Pharmacognosy; Plant origin; Antithrombotic agent; Lichenes; Extract; lichen; antiplatelet; Antiplatelet agent; Thallophyta; Medicinal plant; antithrombosis
• DOI: 10.1002/ptr.1791
• ISSN: 0951-418X

The antiplatelet and antithrombotic activities of a methanol extract of a medicinal lichen, Usnea longissima, were investigated on platelet aggregation in vitro and on pulmonary thrombosis in vivo. The extract showed concentration dependent inhibitory effects on ADP‐induced platelet aggregation, with an IC50 value of 3.6 mg/mL. Using an in vivo mouse thrombotic model in which mice were challenged with an intravenous injection of collagen and epinephrine mixture, oral administration of the extract prior to the injection produced a significant inhibition of thrombotic death or paralysis at 100–200 mg/kg body weight. Aspirin, a representative antiplatelet drug, produced a significant inhibition of thrombotic death at 10–20 mg/kg body weight. The mouse tail bleeding time was significantly prolonged by the addition of the extract. On the other hand, the extract did not show any fibrinolytic activity or alter the coagulation parameters such as activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) in rat platelets in vitro. These results suggested that the antithrombotic activity of U. longissima extract might be due to antiplatelet activity rather than anticoagulant activity. Copyright © 2005 John Wiley & Sons, Ltd.