A drug used for decades to treat liver disease has shown promises as an effective way to slow down the progression of Parkinson's disease.

The findings, by scientists from the University of Sheffield have discovered, suggest regulators should fast-track clinical trials of the drug — ursodeoxycholic acid (UDCA) — that could lead its widespread use in treating the mental-health condition.

The pioneering research, published in the journal Neurology, was led by scientists from the Sheffield Institute of Translational Neuroscience (SITraN), in collaboration with scientists from the University of York.

The research is the first to demonstrate beneficial effects of UDCA on the nerve cells affected in Parkinson's disease. The researchers explained that a mutation in the so-called LRRK2 gene is the single most common inherited cause of Parkinson's disease.

"We demonstrated the beneficial effects of UDCA in the tissue of LRRK2 carriers with Parkinson's disease as well as currently asymptomatic LRRK2 carriers,” said Heather Mortiboys, M.D., with the University of Sheffield. “In both cases, UDCA improved mitochondrial function as demonstrated by the increase in oxygen consumption and cellular energy levels."

Arthur Roach, M.D., director of research and development at Parkinson's UK, which helped fund the study, said: "There is a tremendous need for new treatments that can slow or stop Parkinson's. Because of this urgency, the testing of drugs like UCDA, which are already approved for other uses, is extremely valuable."