Anticoagulant effect and safety assessment of an aqueous extract of Pseudocedrela kotschyi (Schweinf.) Harms and Adenia cissampeloides (Planch. Ex Hook.) Harms

Background: Currently available therapeutic options for thromboembolic disorders are often very expensive, and are associated with unfavorable side effects. Aim: To establish the anticoagulant effect and safety profile of an extract made from of the root bark of Pseudocedrela kotschyi (Schweinf.) Harms and the aerial part of Adenia cissampeloides (Planch. ex Hook.) Harms (PAE). Methods: PAE (0.5-2.0 g/L) effect on Prothrombin time (PT) and activated partial thromboplastin Time (aPTT) were evaluated on whole blood drawn from the marginal ear vein of New Zealand White rabbits. Effect of PAE (250-2000 mg/kg) on bleeding time (BT), and clotting time (CT) in Sprague-Dawley rats were also assessed. Histopathological, hematological, and liver function studies were also carried out to assess the safety for use of PAE (250-2000 mg/kg). Results: PAE had no significant effect (p>0.05) on PT, but resulted in a significant increase (p≤0.05-0.0001) in aPTT. PAE treatment resulted in a significant increase (p≤0.05-0.0001) in BT and CT in vivo, compared with control. Safety studies indicated no deaths with PAE treatment with hematological and liver function tests being normal. Histological studies revealed pathological changes in the liver at a PAE treatment dose of 2000 mg/kg but all doses had no detrimental effect on kidney and stomach tissue. The NOAEL was less than 2000 mg/kg when given orally. Conclusion: PAE has anticoagulant effect in vitro, and is safe to use at oral doses less than 2000 mg/kg.