author(s)
Surbhi, Nirmal Sangwan and Arun K Sangwan

abstract
Ticks are of vast importance in veterinary sciences due to their ability to transmit a wide variety of haemoprotozoan parasites such as Theileria, Babesia etc in domestic animals. Successful feeding of ticks on their host relies on a set of bioactive chemicals concentrated in their highly specialized salivary glands. Salivary chemicals of ticks have the ability to inhibit platelet aggregation in host animal via inhibition of their haemostatic mechanism. The present study targets isolation, characterization of tick saliva contents to understand the biochemical mechanisms of platelet inhibition by the inhibitory tick’s salivary proteins/peptides. Accordingly, hundred pairs of tick salivary glands were dissected out and an extract was prepared by homogenizing them in HEPES buffer. Proteins in fraction nos. 22, 23, 25, 27, 31, 36, 38, 39 and 51 obtained by gel filtration chromatography were found to inhibit thrombin induced platelet aggregation and platelet adhesion to collagen when compared to agonist thrombin. The platelet adhesion inhibition by the proteins/peptides in fractions was significantly higher than agonist and lower than antagonist which indicates inhibition of receptors GP1b, GPVI and integrin α2β1, which are previously reported to be responsible for platelet aggregation. Result indicates inhibition of platelet aggregation in host blood can be possibly achieved through inhibition of platelet activating receptors by inhibitory peptides present in tick salivary gland secretions. Exploration of these anti-platelet aggregating proteins/peptides can be further exploited for raising vaccine to control ticks and ticks borne diseases and also for therapeutic purposes.