In a study funded by the British Heart Foundation, the Wellcome Trust and the Medical Research Council, researchers from the University of Leeds found that one of the scorpion’s toxins, margatoxin, is at least 100 times more capable in preventing neointimal hyperplasia than any other known compound.
Being the most common cause of bypass graft failure, neointimal hyperplasia is the blood vessel's response to injury. It triggers the growth of new cells, causing chronic blockage on the inside of the vessel.
When a vein is grafted onto the heart during a bypass procedure, the injury response begins as the vein tries to adapt to the new environment and different circulatory pressures. The growth of new cells does help strengthen the vein, but the internal cell growth restricts blood flow and ultimately causes the graft to fail.
The toxin works by suppressing the activity of a specific potassium ion channel, a pore in the cell membrane that opens and closes in response to electrical signals, and indirectly enhances delivery of an intracellular messenger, the calcium ion.
In fact, there were a number of good blockers of the ion channel available. Several compounds are developed from plants but margatoxin was the most potent.
It is believed that margatoxin would probably not suitable as a drug that could be swallowed, inhaled or injected. However, it could be used as a spray-on treatment to the vein itself once it has been removed and is waiting to be grafted onto the heart.