Anti-malaria drugs have been found to be a potential new treatment for Parkinson's disease.

Scientists from Harvard Medical School, McLean Hospital, and Singapore's Nanyang Technological University have found two Food and Drug Administration-approved malaria drugs — Chloroquine and Amodiaquine — trigger brain chemistry changes that lead to improvements in behavior and reduce symptoms the disease.

The groundbreaking research, published online in the Proceedings of the National Academy of Sciences, was conducted in laboratory studies involving rats, but the researchers say they have important implications for human patients, as well.

"Our discovery brings hope for the millions of people suffering from Parkinson's disease, as the drugs that we have found to have worked in the laboratory tests have already been used to treat malaria in patients for decades," said Yoon Ho Sup, an expert in drug discovery and design from NTU's School of Biological Sciences.

"Our research also shows that existing drugs can be repurposed to treat other diseases and once several potential drugs are found, we can redesign them to be more effective in combating their targeted diseases while reducing the side effects."

Parkinson's disease is a degenerative disorder of the central nervous system that causes a person to lose the ability to move his or her hands, arms, and legs. It affects three out of every 1,000 persons aged 50 years and older and is currently incurable.

The team of international scientists that conducted the latest study discovered that activating a class of proteins found in the brain, known as Nurr1, protects the brain's ability to generate dopamine neurons. Parkinson's disease disrupts the production of dopamine neurons.

In laboratory tests, the scientists found that by activating Nurr1 — by using the two malaria drugs — rats which had Parkinson's disease had improvements in behavior and showed no signs of the disease.