Can spider venom treat pain?

The bite from a spider the size of your hand is usually something you might prefer to avoid.

But new research is suggesting the venom carried by tarantulas could help to treat a range of diseases.

The toxins carried by the Togo starburst tarantula, which is found in West Africa, cause an excruciating and piercing pain in bite victims.

But scientists have found these toxins also target a previously unknown biochemical pathway in the nerves that sense pain.

This, they say, could lead to a new drugs to treat chronic pain along with other conditions such as epilepsy, IBS, autism and even Alzheimer’s disease.

Dr Jeremiah Osteen, a physiologist who led the research, said: ‘These spiders had millions of years of evolution to come up with these potent and specific toxins.

‘They’re tools one might be hard pressed to design as well in the lab.’

The researchers found the newly discovered toxins cause pain by triggering a channel that allows sodium to enter the cell in a rare class of nerve called A-delta fibres.

The researchers were able to identify two small protein molecules – or peptides – in the spiders’ venom that powerfully activated these nerves in the laboratory.

It is generally thought that A-delta fibres convey the sharp, immediate shock of a burn or a cut. Slower C fibres produce the burning throb that follows.

The researchers were able to isolate A-delta fibres in mice using the toxins and showed that they also appear to play a role in touch hypersensitivity.

This is where light touches can cause discomfort – a common problem in diseases like shingles and chronic pain syndromes.

Experiments also showed that heightened touch sensitivity of a subtype of A-delta fibres, known as Nav1.1-expressing, may play a role in irritable bowel syndrome.

The Nav1.1 subtype of nerves have also been implicated in the development of epilepsy, autism and Alzheimer’s disease.

Dr David Julius, said: ‘These channels are incredibly hard to identify drugs for because the different subtypes are closely related, making it difficult to identify drugs or other agents that act on one subtype and not another.

‘These toxins provide unique tools to start understanding exactly what this particular subtype, Nav1.1, does in terms of pain sensation.’

The researchers, hope they may be able to identify other pain mechanisms by studying the venoms of other creatures.

They are screening hundreds of toxins from poisonous spiders, scorpions and centipedes.

Dr Julius added: ‘There are dozens to hundreds of different active peptides in each animal’s venom.

‘The deeper you look, the more toxins there seems to be.

Source: Daily mail

N.H.KH