Animals

How deadly venom became a medical miracle

A new exhibition at London's Natural History Museum, Venom: Killer and Cure, reveals how humans are harnessing the positive power of venom.Monday, 27 November 2017

By Mark Bailey
Entomologist Justin Schmidt describes the sting of a bullet ant as “like walking over flaming charcoal with a three-inch nail embedded in your heel.”

The Natural History Museum’s venom evolution expert, Dr Ronald Jenner, explains some of the most surprising uses of venom.

Venomous lizards, snails and vipers are inspiring life-changing drugs

“Researchers have turned venoms into effective drugs for the treatment of afflictions. One example is the venom of a lizard called the Gila monster from the southern United States which is helping to treat Type 2 diabetes. A synthetic version of it, when injected, regulates blood sugar, promotes the secretion of insulin, and regulates the emptying of the stomach. This is a blockbuster thing. It comes in two forms and is made by AstraZeneca, with worldwide sales approaching £675 million ($900 million).

There is also a pain relief drug based on the venom of a marine snail,  which is delivered in hospital through injection into the spinal column. It can be used as an alternative to opioid drugs like morphine and is helpful for drug addicts who have become habituated to morphine as well as people undergoing chemotherapy for cancer.

Some vipers have venom that can affect blood pressure and, when isolated, these toxins can even be used to prevent the formation of blood clots during surgery.”

Scorpions featured in primitive 'bombs', packed into clay pots that attackers hurled over the walls of besieged cities.

Venoms have been used as weapons

“Around 2000 years ago people used snake venom on arrows, as documented in Asian, Greek and Roman cultures. However, weapons were usually made with poison from plant extracts or from the skin of poison dart frogs. But ancient armies did use scorpion bombs by hurling clay pots filled with scorpions over city walls.”

The harvester ant is so toxic it's been used as a source of natural highs by indigenous peoples.

Ant bites have shaped human religion and culture

“Various ants have been used for initiation rites. In some cultures adolescents are exposed to the painful stings of ants or wasps as part of their progress into adulthood. Harvester ants – which gramme for gramme are more toxic to mammals than most snake venoms – were used by the indigenous people of southern California. They would swallow dozes alive so they would sting their oesophagus and belly. They would lose consciousness but the hallucinations allowed them to think they could reach the supernatural realm.”

The emerald cockroach wasp injects mind-controlling venom into a cockroach, then lays a single egg on the roach before imprisoning it. The wasp larva eats into the cockroach and feeds off its organs.

Venom plays a vital role in human agriculture

“We have roughly 8,000 venomous species in the UK and 6,500 of those are small parasitoid wasps. Without them, insects which we consider pests because they eat crops would be exploding in numbers.”

Snake bites help some office workers relax

“Some snake bites, especially from the elapid family which includes cobras and mambas, have been used to induce a sense of euphoria. If you are bitten by a cobra you are playing with your life. But there are snake dens in cities in India where respectable people like engineers or IT workers pay to get bitten. Because the venom paralyses them, it relaxes their muscles and is used for stress relief. But that is very weird.”

Horses help to make anti-venoms

Anti-venoms are usually made by immunising horses. They are given a low concentration so there is no adverse effect. The horse’s immune system kicks in and creates antibodies. The blood of the horse is taken and the antibodies are purified and stored, so if you go to hospital with a bite from that snake, they will inject you with the horse’s antibodies.”

Venoms are also proving to be valuable sources of antibiotics.

Expect more venom innovations in the future

“Venom will be an important part of the search for new antibiotics. With resistant superbugs in hospitals, we need to find compounds in nature which can kill microbes, and the venom of many scorpions and snakes contain compounds which can kill bacteria. Venom will also be used to find new treatments. A modified version of the venom of a sea anemone has been used in clinical trials to treat the auto-immune disease psoriasis, and it could help with other auto-immune diseases like multiple sclerosis too.”

 

The exhibition, Venom: Killer and Cure, is at the Natural History Museum in London until 13th May 2018.