PIYAVIT - A COMPLEX PREPARATION FROM THE MEDICINAL LEECH IMPROVES BLOOD RHEOLOGY AND DECREASES PLATELET-AGGREGATION

The in-vivo effects of piyavit (a preparation from the medicinal leech ) on rheological parameters of blood of patients with thrombophlebitis of the greater saphenous vein (TGSV), were studied during the clinica l trial of piyavit. Whole blood viscosity was decreased significantly (p<0.05), at both low (9 sec(-1)) and high (105 sec(-1)) shear rates a fter seven days of piyavit treatment. Piyavit-therapy caused a statist ically significant drop in erythrocyte sedimentation rate by approxima tely 20% (p<0.05). Hematocrit was not significantly distinguishable fr om the pre-treatment level. No significant changes in hemorheological parameters were found in our control group of TGSV patients which were treated with an alternative anticoagulant, phenylline. The comparativ e investigations of effects of piyavit and heparin on platelet aggrega tion and theological parameters of rat and human blood were performed in-vitro. Blood anticoagulated with piyavit had less blood viscosity, RBC aggregation and mechanical fragility of RBCs, and higher RBC filte rability than blood anticoagulated with heparin (these distinctions we re not statistically significant). A comparative study of piyavit and heparin effect on platelet aggregation showed that unlike heparin piya vit did not induce platelet aggregation, even at an extremely high con centration, 50 mg/ml plasma. The ADP-induced platelet aggregation was approximately 5 times less in platelet rich plasma (PRP) incubated wit h piyavit, than in samples incubated with heparin (p<0.005). Results o f our study confirm that piyavit as an anticoagulant and antithromboti c agent may provide an alternative to heparin.