title: Cryptolepine inhibits platelet aggregation in vitro and in vivo and stimulates fibrinolysis ex vivo.
abstract: 1. Cryptolepine--the methylquindolanol alkaloid of Cryptolepsis sanguinolenta was evaluated for its antiplatelet and fibrinolytic effects. 2. It exhibited antiplatelet effects in vitro in human, rabbit and rat PRP with EC50 values ranging between 8.1 x 10(-8) M and 1.7 x 10(-7) M for ADP, AA and thrombin. 3. In the rat, it inhibited ADP-aggregation in vivo with delayed onset and prolonged action. 4. In vitro, cryptolepine disaggregated (dose-dependently) platelets aggregated by ADP, AA and thrombin. 5. In addition, it exhibited an indirect fibrinolytic action in the rat possibly by causing the release of plasminogen activators from the vascular endothelium.
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000328:Adult; D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D005342:Fibrinolysis / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D026121:Indole Alkaloids; D007211:Indoles; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors; D011804:Quinolines; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D013917:Thrombin / Q000494:pharmacology
chemical_list: D000317:Adrenergic alpha-Antagonists; D000470:Alkaloids; D026121:Indole Alkaloids; D007211:Indoles; D010975:Platelet Aggregation Inhibitors; D011804:Quinolines; C024015:cryptolepine; D000244:Adenosine Diphosphate; D013917:Thrombin