Evaluation of Thrombolytic Activity and Brine Shrimp Lethality Bioassay of Methanol Extract of Stems of Tinospora Crispa

Tinospora crispa, a plant belonging to the family of Menispermaceae is a well-known traditional medicinal plant used in Bangladesh. The methanolic extracts of stems of the plant were evaluated for their thrombolytic and preliminary cytotoxic activities. The thrombolytic activity was evaluated using the in vitro clot lysis model while while the screening of cytotoxic activity was done using brine shrimp lethality bioassay. Different concentrations of stem extract were made in isotonic saline (2.5, 5, 10 and 20 mg/ml) and added to pre-clotted human blood (n=13) and the clot lysis activity was determined following 90 minute incubation at 37o C. The results showed that T. crispa stem extract induced mild to moderate (14.8125.73%) and significant (p <0.001) clot lysis activity whereas the standard Streptokinase (30,000 I.U.) evoked a significant (p < 0.001) clot lysis activity (50.1%). In Brine shrimp lethality bioassay, the LC50 values of methanolic crude extract and its pet ether, chloroform and aqueous fractions were found to be 6.43, 0.8. 4.58 and 7.46 g/ml respectively which were comparable to the standard vincristine sulphate (LC50: 0.107 μg/ml). The results of the study demonstrated that the stem of the plant possesses promising thrombolytic activity in vitro when tested on human blood as well as preliminary cytotoxic activity on Brine shrimp. However, further study is needed to see its potentiality as thrombolytic medicine. INTRODUCTION: Hemostasis maintains the integrity of circulatory system after vascular damage. Circulating platelets are recruited to the site of injury, where they become a major component of the developing thrombus. Thrombosis is a critical event in the arterial diseases associated with myocardial infarction and stroke, and venous thromboembolic disorders account for considerable morbidity and mortality. Moreover, venous thrombosis is the second leading cause of death in patients with cancer . Thrombolytic agents that include tissue plasminogen activator (t-PA), Urokinase (UK), streptokinase (SK) etc. are used all over the world for the treatment of these diseases. In India, though SK and UK are widely used due to lower cost, 2, 3 as compared to other thrombolytic drugs, their use is associated with hyper risk of hemorrhage , severe anaphylactic reaction and lacks specificity. Moreover, as a result of immunogenicity multiple treatments with SK in a given patient are restricted . Because of the shortcomings of the available thrombolytic drugs, attempts are underway to develop improved recombinant variants of these drugs .