Anticoagulant Activity of Averrhoa bilimbi Linn in Normal and Alloxan- Induced Diabetic Rats

Abstract

Hypercoagulation, which is often associated with diabetes mellitus may lead to several health problems such as thrombosis, stroke and heart attack. A plant with an anticoagulant effect would be beneficial to counteract these problems. An ethanolic extract of leaves and fruits of Averrhoa bilimbi Linn (Abe) (250 mg/kg) was orally administered to normal and diabetic male Wistar rats for 14 consecutive days. Samples of blood were then drawn after 14 days and centrifuged (5000 rpm,15 min) to obtain the plasma. Clotting time assays were carried out using a microtitre plate reader. The present study found that ethanolic extract of the leaves and fruits of A. bilimbi showed very significant anticoagulant effect on rats (P < 0.01). The high level of oxalic acid in A. bilimbi, which range from 10.5 to 14.7 mg/g in green, unriped fruit and 8.45 to 10.8 mg/g in ripe fruit could provide the anticoagulation effect since oxalic acid is a metal cation chelator. Oxalate presumably binds to blood calcium, removing calcium ion from the blood, thus inhibiting the clotting process.