Preliminary study on leech crude extract as an anti-coagulant agent

Hirudin is the generic name for a family of closely related homologous peptides that are all found in
the cranial salivary glands of medicinal leech (Wallis, 1996). In 1984, the blood-thinning agent
(anticoagulant) hirudin was isolated for the first time from leech salivary glands (Weinnberg, 1994).
Today, hirudin is the most specific and active of known thrombin inhibitors not influencing on other
peptidases (Hofsteenge and Stone, 1987). Hirudinea sp. (Buffalo Leech) was used for the isolation of
hirudin for anti-coagulant application. The leech crude extract was prepared by using conventional
method and tested to fresh rabbit blood. The time of blood clotting was recorded by using a drop
method (Prakasam et. al., 2005). Three replicates were applied for each treatment. The results showed
that the rabbit blood treated with leech crude extract gave the longest time of blood to clot with average
and standard deviation values of 15.33±0.6 minutes when compared to treatment with distilled water
and that on blood only (control) with an average and standard deviation values of 2.83±0.3 and
0.59±0.01 minutes, respectively. These results revealed that crude extract of leeches contain an anticoagulant
agent to prevent blood from clotting. The study on leech crude extract will be extended to
include purification of hirudin for applications as anti-coagulant agent.