The box jellyfish is the world's most venomous creature, with a sting from its trailing tentacles causing intense pain, necrosis of the skin, and in some cases death by cardiac arrest. Now, however, scientists have found an antidote for such stings – and it's an existing cholesterol-lowering drug.

Led by Assoc. Prof. Greg Neely and Dr. Raymond (Man-Tat) Lau, a team at Australia's University of Sydney started by using the CRISPR gene-editing tool to knock out different genes in a large collection of human cells.

Box jellyfish venom was then added to the vat which contained those cells. While that venom killed most of the cells, a few survived. By analyzing those survivors and checking which human factors they lacked, the scientists were thus able to ascertain that one missing factor – a protein called ATP2B1 – is necessary in order for the venom to be effective. And ATP2B1 requires cholesterol.

"Since there are lots of drugs available that target cholesterol, we could try to block this pathway to see how this impacted venom activity," says Lau. "We took one of those drugs, which we know is safe for human use, and we used it against the venom, and it worked."

After first being tested on unmodified human cells, this drug was then injected into mice that had been exposed to the venom. As long as the medication was administered within 15 minutes of exposure, it stopped the necrosis and pain. The scientists have yet to determine if it also prevents cardiac arrest, and will be further researching that aspect of the treatment.

Industry partners are now being sought to help commercialize a jellyfish-venom-specific version of the drug – there were in fact actually two drugs that worked, namely MβCD and HPβCD. The final product will most likely take the form of a topical cream or spray.

A paper on the research was published this week in the journal Nature Communications.