The world’s most venomous beastie is neither a snake nor a scorpion, it’s actually the box jellyfish – a creature equipped with enough venom to kill over 60 people. Now, researchers have discovered an antidote to the sea wasp’s lethal sting.

Publishing their findings in Nature Communications, University of Sydney researchers managed to identify a molecule that acts as an antidote to this venom. However, it’s important to note that so far, they have only tested it out on human cells in a dish and mice, so it’s still early days.

Named for its cuboid shape, the Australian box jelly (Chironix fleckeri) has up to 60 tentacles, each as long as 3 meters (10 feet) and laden with millions of venom-filled hooks. The aim of this powerful venom is to stun or kill prey quickly so that it doesn't damage the jelly’s tentacles by trying to wriggle free.

The cnidarians can be found off the coast of Northern Australia and throughout Indo-Pacific waters, racking up speeds of up to 7.5 kilometers (4.6 miles) per hour as they hunt for fish and prawns.

Those unlucky enough to get stung suffer excruciating pain, skin necrosis, and sometimes even cardiac arrest and death just minutes after the encounter. Many victims go into shock and drown as the pain is so severe. Those that survive a box jelly encounter can suffer pain for several weeks and experience scarring.

"It is super exciting," said Greg Neely, an associate professor at Sydney’s School of Life and Environmental Sciences.

"We were looking at how the venom works, to try to better understand how it causes pain. Using new CRISPR genome-editing techniques we could quickly identify how this venom kills human cells. Luckily, there was already a drug that could act on the pathway the venom uses to kill cells, and when we tried this drug as a venom antidote on mice, we found it could block the tissue scarring and pain related to jellyfish stings."

CRISPR is a technique that allows scientists to add, remove, or alter genetic material within an organism. It’s been used for all sorts of things, from fixing muscular dystrophy in dogs to treating a rare blood disorder in humans.

The researchers used this method to knock different genes out of millions of human cells. Using trial and error, they looked at which cells survived an encounter with box jelly venom. This enabled them to spot features of humans that allow the venom to take hold.

"The jellyfish venom pathway we identified in this study requires cholesterol, and since there are lots of drugs available that target cholesterol, we could try to block this pathway to see how this impacted venom activity. We took one of those drugs, which we know is safe for human use, and we used it against the venom, and it worked," said lead author Dr Raymond Lau. "It's a molecular antidote."

The team found that in the mice and human cells, their antidote prevented skin necrosis, scarring, and pain. More research is needed to see if it can also stop a heart attack.

The antidote needs to be applied to the skin within 15 minutes of being stung. The researchers injected it during their trial, but they hope to develop a topical spray. They are currently applying for funding to further their research.