Could Scorpions Cure Cancer?

The uses of toxins in modern medicine

The uses of toxins

A toxin is defined as a poison of bacteria, plant or animal origin. These are substances that living organisms have developed to protect themselves, and are normally harmful or even deadly. But could these toxic substances be useful?

Botox is probably the most well-known toxin that we now use for other purposes. Its full name, botulinum toxin, is derived from the Latin botulus, meaning sausage. It is so called because it is produced by bacteria that were first discovered in poorly prepared sausages during the 18th century. Botulinum toxin is one of the deadliest substances known to mankind. On the LD50 toxicity scale, which measures how much of a substance would be required to kill a number of people, Botox has an estimated median lethal dose of 0.000001 mg/kg. That means that just 0.00007mg would be enough to kill a 70kg human. A couple of teaspoons could wipe out the whole population of the UK. A couple of kilograms, the world. However, Botox is now most commonly used to smooth out wrinkles. A few billionths of a gram, dissolved in saline are injected into the muscles of the face, which blocks signals from nerves and means that the muscle can no longer contract and cause wrinkles. Botox is also used to treat a range of medical conditions such as eye disorders, muscle stiffness and movement disorders, to name a few.

Scorpion venom is also now being used in brain tumour surgery. Normally, it is very hard for brain surgeons to distinguish tumour from healthy brain tissue; they rely on MRI scans of the patient’s brain. This is very risky, as they may not end up removing all the tumour, in which case the patient still has cancer, or they may remove more tissue than necessary, damaging the brain. This is where scorpions come in. Scientists have created a synthetic version of deathstalker scorpion venom (without the poison), as the venom seeks out cancer cells. By embedding a chlorotoxin (fluorescent dye) in the venom molecules, it is possible to make tumours light up under infrared light. This synthetic venom with chlorotoxin is called Tumour Paint, and allows surgeons to see the brain tumour through a screen, meaning it is much easier for them to operate with much greater accuracy.

Toxins also have many other uses in medicine. The anticoagulant (preventing blood from clotting) properties of pit viper venom can help develop blood thinner drugs which can help treat heart conditions. Tetrodotoxin (TTX), the neurotoxin found in pufferfish can also be used to treat patients with chronic pain as it prevents nerves from sending signals to each other. Too much TTX means that the nerves cease to function but the right amount can prevent pain signals from travelling. It is currently being trialled, aiming to help chemotherapy patients with residual pain from their treatment or diabetes patients with chronic pain.

Ruby V