Deadly Spider Venom Could Ward off Stroke Brain Damage 0

{By Ian Sample,
The Guardian}

Doctors have stumbled on an unlikely source for a drug to ward off brain damage caused by strokes: the venom of one of the deadliest spiders in the world.

A bite from an Australian funnel web spider can kill a human in 15 minutes, but a harmless ingredient found in the venom can protect brain cells from being destroyed by a stroke, even when given hours after the event, scientists say.

If the compound fares well in human trials, it could become the first drug that doctors have to protect against the devastating loss of neurons that strokes can cause.

Researchers discovered the protective molecule by chance as they sequenced the DNA of toxins in the venom of the Darling Downs funnel web spider (Hadronyche infensa) that lives in Queensland and New South Wales.

Venom from three spiders was gathered for the study after scientists trapped and “milked exhaustively” three spiders on Orchid beach, about 400km north of Brisbane.

The molecule, called Hi1a, stood out because it looked like two copies of another brain cell-protecting chemical stitched together. It was so intriguing that scientists decided to synthesise the compound and test its powers. “It proved to be even more potent,” said Glenn King at the University of Queensland’s centre for pain research.

Strokes occur when blood flow to the brain is interrupted and the brain is starved of oxygen. About 85% of strokes are caused by blockages in blood vessels in the brain, with the rest due to bleeds when vessels rupture. Approximately six million people a year die from stroke, making it the second largest cause of death worldwide after heart attacks.

When a stroke happens, the oxygen level in the brain drops. This forces the brain to burn its primary fuel, glucose, very differently. Instead of oxidising glucose for energy, the brain switches to a process called anaerobic glycolysis. The reaction releases energy to keep the brain working, but it also produces acid, which can cause brain cells to die.

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