Scientists may have discovered the first antidote to the deadliest mushroom known to humans

• Death cap mushrooms kill up to 100 people per year and sicken thousands more but have no antidote.
• Scientists used CRISPR to help identify a chemical that could become the first death cap antidote.

The death cap is the deadliest mushroom known to humans. Each year, it kills an estimated 100 people and sickens thousands more.

Many of its victims are unsuspecting foragers who mistake it for the edible fungi it resembles, like puffballs and paddy-straws.

There is no antidote to the mushroom's deadly toxin. The only way to survive if you mistakenly eat one — even downing just half a cap could shut down your liver — is a trip to the ER.

But that may change soon enough.

A recent study in Nature Communications finally found a possible death cap mushroom antidote. The researchers report that an FDA-approved compound known as indocyanine green (ICG) can inhibit the mushroom's deadly toxin.

A death cap mushroom antidote is long-awaited

Scientists have been studying death cap mushrooms since the early 1700s but an antidote has largely eluded them because "we know little about how mushroom toxins kill cells," Qiaoping Wang, a professor of pharmacology at Sun Yat-Sen University and one of the study's lead authors, told Insider.

Many toxins like cyanide, botulinum toxin, and asbestos can be destroyed or denatured by heating, drying, cooling, or boiling them. But none of these methods work on the death cap's toxin, alpha-amanitin.

To identify a potential antidote, Wang and his colleagues turned to the gene-editing tool CRISPR. They screened thousands of human genes and discovered that a promising type of enzyme called STT3B. In particular, cells that lacked this STT3B survived when the scientists poisoned them with alpha-amanitin.

But deactivating STT3B in cells with CRISPR isn't something you can just do in a hospital on a poisoned, dying patient. To identify a possible antidote for death cap victims, the researchers took the additional step to test various chemicals and their affect on STT3B.

They found a promising candidate in the chemical indocyanine green. "ICG is a potential STT3B inhibitor that can prevent AMA-induced cell death," they reported in the study.

Will the antidote work for humans?

ICG is a dye that is currently used to diagnose liver and cardiac activity and check anomalies in blood vessels, tissues, and lymph nodes. When the researchers tested ICG in mice poisoned with the death cap mushroom toxin, the results were eye-opening.

"ICG has demonstrated significant potential in mitigating the toxic impact of alpha-amanitin in liver cells and mice," Wang said.

About 50% of mice that received the ICG antidote survived the toxin. Moreover, no side effects were observed in mice as a result of the treatment.

Of course, further research is necessary to determine any therapeutic benefits in human subjects.

"To this end, the research team intends to conduct human trials to assess ICG's efficacy in individuals who have recently ingested toxic mushrooms," Wang told Insider. "These tests will yield more definitive results and provide a clearer picture of ICG's potential to revolutionize the treatment of mushroom poisoning," Wang said.