Soothing snail spit
Did you know that the fastest part of a sea snail is its teeth? Well, now that you know a sea snail has teeth it will amaze you to know that not only are the teeth speedy they carry substances that may be the basis of a breakthrough in pain relief for human beings.
Sea snails, like their terrestrial brethren, are languorous creatures. Their somnolent modus operandi may make them well suited to holidays in the Caribbean but it does make them much of hunter. The only thing a sea snail will run down is sand and that does not make much of a meal. To make up for their lack of bodily agility marine cone snails have developed a range of chemical weapons known as conotoxins. As an unsuspecting fish passes by with a disdainful eye, smug in their speed superiority over the sea snail, the snail can shoot its needle-like teeth from its mouth like harpoons laden with conotoxins. The fish dies from a combination of surprise, embarrassment and the nerve effects of the conotoxins (mostly the conotoxins).
Within the brew that makes up the snailâ€™s conotoxins are several peptides that can relieve neuropathic pain that is otherwise difficult to treat and they do it without any addiction developing (as happens with morphine). Researchers have been looking at ways to use these peptides in human beings but the problem is that there are very few peptide drugs that can be taken by mouth. This is because the peptides are not very stable and are broken down in the digestive tract. The pain reliever Prialt for example is a synthetic version of a conotoxin and must be injected direct into the spinal cord with a surgically implanted pump. Thanks to Australian researchers that may have changed.
Researchers from the University of Queensland have found a way to tie the two ends of the peptide alpha-conotoxin Vc1.1 together (cyclization) so that it becomes stable and can be taken in a pill. In animal tests the snail spit pill has proved as powerful as gabapentin, the most popular drug currently for neuropathic pain, even though the dose required of the conotoxin is one per cent that of the gabapentin.
The low dose required, non-addictive nature, and the fact that it can be taken orally may make the snail spit drug a revolution in the treatment of severe nerve pain.