Spider venom-inspired drug aims to reverse heart attack damage

For the first time, scientists are testing whether a novel medicine inspired by spider venom can reverse tissue damage caused by a heart attack. Starting next summer, the team plans to test the molecule’s safety in a clinical trial in Australia.

The molecule, a small protein called Hi1a, mimics one produced by Australian funnel-web spiders. It works by preventing heart tissue from becoming too acidic during a heart attack.

The hope is that Hi1a will become the first drug to directly treat tissue damage caused by heart attacks, according to a team statement. While it will initially be developed for use in hospitals, the goal is that it could one day also be administered by first responders, the team told Live Science in an email. The ideal time to administer the drug after a heart attack is not yet known, but the authors suspect it “does not need to be administered quickly,” they said.

Hi1a could also be used to increase the number of donor hearts available for transplant, the team added. For example, Hi1a could protect donor hearts from damage that occurs during the recovery process.

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Hi1a targets a small passage called acid-sensing ion channel 1a (ASIC1a), which allows substances to enter and exit cells all over the bodyincluding in the circulatory system.

During a heart attackheart muscle cells stop receiving oxygen due to reduced blood flow. This lack of oxygen triggers a cellular chain reaction what activates ASIC1a channels on the surface of cardiac muscle cells. With ASIC1a channels open, charged molecules flow in and make heart tissue very acidic. This causes the tissue to die.

Hi1a blocks ASIC1a channels, short-circuiting this process, Glenn Kingprofessor of molecular bioscience at the University of Queensland in Australia, told Live Science in an email. In a 2023 study published in European Heart JournalKing and colleagues showed that injecting Hi1a into mice could protect the heart from damage caused by a lack of blood flow during a heart attack. Similar effects were observed in human heart muscle cells in a Petri dish.

Medical illustration of a person's chest showing only the outline of the body in blue, the outline of the lungs in blue and the heart in red.

Preclinical studies suggest that the new drug prevents the death of heart muscle cells as a result of a lack of oxygen during a heart attack. (Image credit: magicmine via Getty Images)

Although H1a appears to have beneficial effects in rodents, the same cannot be said for other animals that prey on funnel webs.

“Hi1a does something very different from the acid-sensitive ion channels of birds, which are predators of spiders,” King said. “Rather than inhibiting these channels, it actually activates them and in doing so causes pain – so we think the spider may use Hi1a defensively to cause pain to potential predators.”

If the initial human trial is successful, the research team will move on to larger trials. They will use these later trials, known as Phase II and Phase III, to better determine the drug’s safety and effectiveness in a broader range of people.

However, clinical trials take many years to complete, so it will be some time before Hi1a is available to patients, if at all.

Several drugs to reverse heart damage have shown promise in animals, he said. Heerajnarain Bulluckconsultant cardiologist for the National Health Service and honorary senior clinical professor at the University of Leeds in the United Kingdom, told Live Science in an email. However, all of these drugs failed in trials, said Bulluck, who is not involved in the research.

So far, the only cardioprotective drug that has reached a Phase III clinical trial has not been approved because led to strokes.

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