A DRUG used to treat enlarged prostate may also help slow the progression of Parkinson's disease.
An international collaborative study has found the drug called Terazosin can stop cells dying and may prevent the degeneration of the nervous system - reducing the signs, symptoms and complications of Parkinson's disease.
The incurable degenerative condition that affects a person's control of their body movements currently affects 100,000 people in Australia.
The findings, published this week in the Journal of Clinical Investigation, are the result of an collaboration between researchers in China and the University of Iowa in the US.
Senior study author Michael Welsh, director of the Pappajohn Biomedical Institute at the University of Iowa said the findings have the opportunity to change the lives of people with Parkinson's disease "and possibly other types of neurodegenerative disease".
"Current medicines can partially alleviate some of the symptoms of Parkinson's disease. But today we have zero treatments that change the progressive course of this neurodegenerative disease.
"That's a terrible state, because as our population ages Parkinson's disease is going to become increasingly common," said Professor Welsh.
The discovery came after co-senior study author Leu Lie from Beijing Institute for Brain Disorders found that terazosin - a drug that helps ease enlarged prostate or benign prostatic hyperpasia (BHP) by relaxing the muscles of the bladder and prostate - also had the ability to activate an enzyme called PGK1 which is critical for cellular energy production.
When they tested the terazonin in rodents, the drug appeared to slow or stop the loss of nerve cells.
"When we tested the drug in various different animal models of PD, they all got better," said Professor Liu. "Both the molecular changes in the brain associated with cell death and the motor coordination in the animals improved."
The researchers also studied thousands of male patients with both BHP and Parkinson's. They looked at 2880 men with Parkinson's taking terazonin or similar drugs that target PGK1 and a comparison group of more than 15,000 Parkinson's patients taking a different treatment for BHP.
It showed that men living with Parkinson's disease who were taking terazonin for enlarged prostate had reduced rates of progressive motor disability compared to men taking a different drug called tamsulosin.
University of Iowa neurologist and co-researcher Dr Nandakuma Narayanan said they were now recruiting patients in Iowa for further research and clinical trials.
"What is particularly exciting is that terazosin is a 'repurposed drug'. So, we have a lot of safety data already from its clinical use to treat enlarged prostate," he said.
"This is the beginning of what we hope is a sustained and rigorous effort to test this molecule prospectively in order to really determine whether this works."
The team also included researchers from Peking University and Beihang University in China, the University of Barcelona, Spain, and the University of Brescia, Italy.