Antithrombotic Activity of the Steroids and ent -Kaurane Diterpenoids from Canna indica Rhizomes

Canna indica L . Cannaceae, is a valuable plant used for the treatment of many conditions. However, the scientific evidence to support the traditional use for treatment of heart diseases is scarce. Based on previously reported antithrombotic effect of C. indica , this study aimed to isolate pure compounds from its hexane fraction, and evaluate antiplatelet and anticoagulant activity of isolated compounds. NMR and MS spectroscopic methods were used to elucidate compound structures. The antiplatelet activity was tested by a turbidimetric method. The anticoagulant effect was examined by measuring prothrombin time, activated partial thromboplastin time and thrombin time. This is the first report on the isolation of 8 known compounds from C. indica : 24-methylenecycloartan-3β-ol ( 1 ), stigma-4-ene-3-one ( 2 ), stigmast-4-ene-3,6-dione ( 3 ), 6β-hydroxystigmast-4-en-3-one ( 4 ), β-sitosterol, ent -kaur-15-ene-19-al-17-oic acid ( 5 ), 16α-hydro-19-al- ent- kauran-17-oic acid ( 6 ) and 16 α -hydro-19-ol- ent -kauran-17-oic acid ( 7 ). β-Sitosterol and 16α-hydro-19-al- ent- kauran-17-oic acid were previously documented to have antithrombotic effects. This study proved for the first time that 1 , 2 , 3 , 4 and 5 showed dose-dependent antiplatelet effects. Furthermore, 2 exposed the highest inhibitory effect on ADP-induced platelet aggregation (at 0.4 mg/ml, mean percentage inhibition, 77.27%) and affected the intrinsic blood coagulation with prolonged activated partial thromboplastin time. Compound 1 had a very mild effect on ADP-induced platelet aggregation. No anticoagulant activity was observed for 1 , 3 , 4 , 5 and 7 . C. indica rhizome is a potential source of antithrombotic compounds for treating and preventing heart diseases. Further studies should be done to clarify the mechanisms of antithrombotic action and identify more bioactive compounds from this plant. Graphical Abstract