In vitro thrombolytic potential of root extracts of four medicinal plants available in Bangladesh

INTRODUCTION

Like other developing countries, thromboembolic disorders are one of the main causes of morbidity and mortality in Bangladesh.[1] To dissolve clots commonly used thrombolytic agents are alteplase, anistreplase, streptokinase, urokinase, and tissue plasminogen activator.[2] All available thrombolytic agents still have significant shortcomings, including the need for large doses to be maximally effective, limited fibrin specificity, and bleeding tendency.

Since ancient times, herbal preparations have been used for the treatment of several diseases. Herbal products are often perceived as safe because they are “natural.”[3] Epidemiologic studies have provided evidence that foods with experimentally proven anti-thrombotic effect could reduce the risk of thrombosis. Herbs showing thrombolytic activity have been studied, and a few significant observations have been reported.[4] Advances of phytochemistry and identification of plant compounds that are effective in curing certain diseases has renewed interest in herbal medicines. Continued investigation in this area will provide new insights and promote progress toward the development of the ideal thrombolytic therapy, characterized by maximized stable coronary arterial thrombolysis with minimal bleeding.

Since the plants Acacia nilotica, Lagerstroemia speciosa, Azadirachta indica, and Justicia adhatoda contain a variety of water soluble phytoconstituents,[5678] it is possible that root extracts of these plants may affect thrombolysis. Thus, the aim of this study was to examine the thrombolytic potential of crude extract of roots of the selected four plants by using in vitro clot lysis model described by Prasad et al.[9] and Ratnasooriya et al.[10]

SUBJECTS AND METHODS

RESULTS

Addition of 500 μl of streptokinase of 30,000 IU and 15,000 IU concentrations to tubes showed highly significant (P < 0.001) clot lysis of 47.21% and 24.73% respectively comparing with 5.35% clot lysis of normal saline considered as a negative control.

At 5 mg/ml concentration of root extract of A. nilotica, A. indica, and J. Adhatoda showed 15.1%, 21.26%, and 19.63% clot lysis activity respectively, which were highly significant (P < 0.001) comparing with negative control (normal saline). At same concentration, 15.49% clot lysis activity was found for L. speciosa that was significant (P < 0.05) compared with 5.35% clot lysis activity of normal saline [Table 1].

Table 1

Potentiality of n-hexane extracts of roots of ANRE, LSRE, AIRE and JARE on human blood clot lysis in vitro

DISCUSSION

The present results clearly show that saline water soluble root extract of selected plants have thrombolytic and/or fibrinolytic effect (s) as it reduces the clot weight. The results showed, for the first time, those roots of selected four plants possess thrombolytic activity.

The test model used is a newly developed, validated, sensitive, reliable, and simple technique[6] that can be performed with limited facilities available.

Various research works are undertaken in quest of thrombolytic drugs. More site specificity with fewer side effects of thrombolytic drugs are desirables in any natural thrombolytic product. Herbal drugs can be a source to address this concern. Few herbal medicines exert thrombolytic or fibrinolytic effects such as Fangonia arabica,[12] Artmisiae folium,[13] Hemidesmus indicus,[14] garlic,[15] and tea.[10]

This is an important finding, which may have implications in cardiovascular health especially in atherothrombotic patients. This is only a preliminary study and to make the final statement about the potentiality of these herbs as thrombolytic drugs may require further study. Studies may be undertaken to identify the chemical structure of the active ingredients of the root extracts and to elucidate the exact mechanism of action.