To many, Australia is known as home to some of the world’s most dangerous animals. On land, at sea, or in the air, there is always something to be found that can make life miserable. From snakes and spiders to cone snails and crocodiles, it certainly won’t be due to a lack of choice. And if all that is not enough, we can now add trees to the list. Indeed, there are stinging trees there too.
If you are traveling in the northeast of Australia, it is best to watch out for nettle trees. In the language of the local indigenous people, they are known as gympie-gympie. In Latin, the name sounds less cheerful, dendrocnide. Because there is no reason to be happy when you come into contact with this plant. A fraction of a second is enough to feel pain for hours and sometimes days or weeks. Some even describe it as the worst pain they have ever experienced.
If you are stung by this member of the nettle family, say on your hand, it would feel like it is on fire and being electrocuted at the same time. This fiery start then gives way to a feeling that makes you think that the body part in question has become stuck between a slammed car door.
And as if that were not enough and you finally think you have got rid of it, a final phase called allodynia finally occurs. During this period, taking a shower or just scratching may be enough to make the pain flare up again.
Scientists have now found out why the plant is capable of doing this. The gympie-gympie is covered with hollow needle-like hairs, better known as trichomes. Just like the stinging nettles we know, these hairs contain harmful substances.
It was previously thought that the moroidine molecule, one of those substances, caused the pain. However, further testing in human volunteers did not result in the painful symptoms observed when stung by the plant.
But now scientists have found the real culprit. A mini-protein they have called ‘gympietide’. Even if this toxin was replicated in the laboratory, it could still cause the same pain reaction. This type of protein appears to have a complicated three-dimensional structure, supported by a network of connections. This makes it very stable.
This is not good news for the victim, because it means that it will probably remain intact in the human body for a long time. And that also means that you have to stay on your guard at all times. After all, there are anecdotes in which people were stabbed by 100-year-old samples stored in a herbarium.
Remarkably, the Australian researchers saw that the shape of the gympietids resembled that of the proteins from the venom of certain spiders, cone snails, and scorpions. These types of proteins are known to affect ion channels in nerve cells. They ensure that those channels cannot close properly anymore, making it difficult for the cell to stop the pain signal.
How the gympietids influence ion channels and nerve cells are currently under investigation. Hopefully, this new research will provide treatment therapies that doctors can use to control pain.