Phenanthrenes Isolated from Diocorea Batatas Decne Peel with Anti-Platelet Aggregation Activity Via Direct Factor Xa Inhibitory Activity

Phenanthrene is a class of phenolic metabolites present in Dioscorea batatas which has bioactivities such as antifungal, anti-inflammatory and antioxidative activities. Two phenanthrenes isolated from D. batatas Decne peel, exhibited inhibition against factor Xa and platelet aggregation. They were evaluated for their anti-FXa and anti-platelet aggregation properties by monitoring clotting time, platelet aggregation, FXa activity, and thrombus formation. They exhibited inhibition of the catalysis of FXa and inhibition of adenosine diphosphate- and U46619- induced platelet aggregation. They also inhibited phosphorylation of myristoylated alanine-rich C kinase substrate induced by ADP- and U46619 and the expression of P-selectin, while activating GP IIb/IIIa 1 in platelets. Improved production of nitric oxide and inhibition of endothelin-1 oversecretion were observed. In vivo studies demonstrated the enhanced antithrombotic effects and elicited anticoagulant effects of the compounds. Their anti-thrombotic efficacy were equivalent to rivaroxaban.