Plant enzyme 'could help treat Huntington's disease'

Thale cress may be the key to removing the toxic protein found in the brains of patients with the incurable condition

An enzyme found in plants could help treat Huntington’s disease, scientists hope.

Researchers at the University of Cologne, in Germany, found that plants were able to remove the protein clumps which build up in the brain of Huntington’s patients.

They do it using an enzyme called stromal processing peptidase (SPP) and the scientists have now been given funding from the German government to try to turn it into a treatment.

‘Brain cell killer’

About 7,000 people in Britain live with Huntington’s, an incurable degenerative disease caused by a single defect in the huntingtin gene, which turns a usually helpful protein into a brain cell killer, robbing the carrier of movement, speech and dignity.

Scientists found that when they introduced huntingtin proteins into thale cress, the plant was able to remove the clumps and avoid any harmful effects.

“We were surprised to see plants completely healthy, even though they were genetically producing the toxic human protein,” said Prof David Vilchez at Cologne University’s faculty of medicine.

Current medications for Huntington’s only treat symptoms rather than reversing the underlying condition.

The team showed that when they applied a synthesised version of SPP to human cellular models of Huntington’s, the enzyme cleared out the damaging protein.

The researchers have now won funding from the German Federal Ministry of Education and Research to found a start-up to produce plant-derived therapeutic proteins and want to test them as potential therapeutics to treat neurodegenerative diseases.

‘Hope for hereditary diseases’

“I believe that plant molecular mechanisms hold the key to discovering new drugs that can prevent human diseases,” said Dr Seda Koyuncu.

“We usually forget that some plants can live thousands of years and should be studied as models of ageing research.

“Over the past years we have seen several promising approaches to treating hereditary diseases like Huntington’s. We are confident that our plant synthetic approach will lead to significant advances in the field.”

Symptoms of Huntington’s usually become evident between the ages of 30 and 50. They can include difficulty concentrating, clumsiness, involuntary jerking and problems swallowing.

The disease is progressive and full-time nursing care is needed in its latter stages.

Sufferers rarely survive more than 20 years after symptoms begin and children of patients have a 50 per cent chance of inheriting the responsible gene.

The research was published in the journal Nature Ageing.