Breakthrough cobra venom antidote discovered

A breakthrough from an international research team has produced a cheap new antidote to deadly cobra venom using a surprising source—a commonplace blood thinner.

Cobras aren’t technically the world’s most venomous snakes—that honor goes to Australia’s notorious inland taipan—but they’re still incredibly dangerous. Exact numbers are unclear, but it’s estimated species like the nubian spitting cobra regularly kill thousands of people each year. Meanwhile, upwards of a hundred thousand more victims annually contend with serious injuries, even amputations. These emergencies also often occur in regions that lack access to adequate medical treatment. Existing cobra venom antidotes date back to the 19th century, but still cost tens of thousands of dollars and are largely ineffective at stopping necrosis.

As detailed in a study published on July 17 in the journal Science Translational Medicine, collaborators working at the University of Sydney, the Liverpool School of Tropical Medicine, as well as centers in Canada and Costa Rica recently discovered a potentially revolutionary solution. Using CRISPR gene-editing techniques to study potential venom blockers, the team found that repurposing a low-cost, common, relatively inexpensive blood thinner called heparin along with related drugs successfully stops tissue death from cobra bites.

The new antidote “could drastically reduce the terrible injuries” caused by cobras, according to an accompanying statement from Greg Neely, a study corresponding author and University of Sydney researcher. Neely also notes the drug may potentially slow the venom’s spread to improve survival rates.

“Heparin is inexpensive, ubiquitous and a World Health Organization-listed Essential Medicine,” added Tian Du, a study lead author and PhD student at the University of Sydney. “After successful human trials, it could be rolled out relatively quickly to become a cheap, safe and effective drug for treating cobra bites.”

To accomplish the feat, researchers used the same methodology that helped them discover a box jellyfish antidote in 2019. First, they employed CRISPR to identify the human genes hijacked by cobra venom, which initiates necrosis around the bite wound. One of these necessary enzymes are those that help produce the molecules heparan and heparin—the former is located on a cell’s surface while the later is released in immune responses. The structural similarities between the two molecules allows cobra venom to bind to both of them. Upon injection, the new heparinoid drugs flood a wound region with decoy heparinoid molecules that bind and neutralize the venom toxins that cause tissue death.

The World Health Organization considers snakebites one of the most neglected and deadliest tropical disease issues, particularly for rural populations in low- and middle-income nations. In 2019, it went so as to announce an initiative aimed at cutting the annual number of occurrences in half by 2030.

“That target is just five years away now. We hope that the new cobra antidote we found can assist in the global fight to reduce death and injury from snakebite in some of the world’s poorest communities,” Neely said on Wednesday.