Effects of anticoagulant from Spirodela polyrhiza in rats.

A fibrinolytic protease was purified from an Oriental medicinal herb, Spirodela polyrhiza (Choi, H. S., et al., Biosci. Biotechnol. Biochem., 65, 781-786 (2001)). The protease hydrolyzed not only fibrin but also fibrinogen. The enzyme had an anticoagulant activity measured with activated partial thromboplastin time, thrombin time, and prothrombin time in rat plasma. It doubled all three at 69, 29, and 221 nM, respectively. The protein had anticoagulant activity when given intravenously and orally. The maximum delay in the activated partial thromboplastin time was at the dose of 0.52 and 4.2 mg/kg for intravenous and oral administration, respectively. This protein may be useful in clinical applications for anticoagulation.