Discovery and development of direct Xa inhibitors Xa was identified as a promising target for the development of new anticoagulants in the early 1980s. In 1987 the first factor Xa inhibitor, the naturally occurring compound antistasin, was isolated from the salivary glands of the Mexican leech "Haementeria officinalis". Antistasin is a polypeptide and a potent Xa inhibitor. In 1990 another naturally occurring Xa inhibitor was isolated, tick anticoagulant peptide (TAP) from extracts of the tick "Ornithodoros moubata". TAP and antistasin were used to estimate factor Xa as a drug target. Blood coagulation is a complex process by which the blood forms clots. It is an essential part
Insects in medicine preliminary progress has been made with investigation of the therapeutic properties of tick anticoagulant peptide (TAP) and Ixolaris a novel recombinant tissue factor pathway inhibitor (TFPI) from the salivary gland of the tick, "Ixodes scapularis". Additionally, Ixolaris, a tissue factor inhibitor has been shown to block primary tumor growth and angiogenesis in a glioblastoma model. Despite the strong potential of these compounds for use as anticoagulants or immunomodulating drugs no modern medicines, developed from the saliva of blood-sucking insects, are currently on the market. Like plants and insects, arachnids have also been used for thousands of years in traditional medical