/ 24 January 1997

… and they may treat diseases

A TICK that has a toxin in its saliva that can kill animals may also have, in this secretion, a compound that can be used to treat human diseases.

The Sandtampan tick, common to the arid regions of the Northern Cape, lives, like most ticks, on the blood of its host. So when it attaches to the skin of its victim and begins to suck, an anti-coagulant in its saliva prevents the blood from clotting and keeps it flowing.

“Pharmaceutical companies are constantly looking for new anti-coagulants,” says AW Neitz, one of a team of biochemists from the University of Pretoria presenting their research on the Sandtampan’s saliva at the conference in Grahamstown.

Anti-coagulants are often used to treat heart disease, as they present blood from clotting and clogging up the arteries.

But testing the anti-coagulant in ticks is finicky work. First, the researchers have to collect the ticks – at least 400 of them – then they put each one under a microscope and carefully detach their salivary glands. The glands are ground up and an extract is made from them, which yields a very little amount to work with.

This substance will contain several hundred different compounds, so complicated procedures are applied to separate the anti-coagulant and get it pure. Only at this point can research begin on the anti- coagulant itself.

This tick may be dangerous in the veld, but under the microscope it is a fairly simple creature to deal with. “It’s not like a spider that’s aggressive. It’s a fairly slow-moving creature so there’s little danger of being bitten,” says Neitz.