Researchers have discovered that a molecule in the tapeworm drug niclosamide might be able to protect against Parkinson's disease-related neuronal damage. The findings bring us closer to slowing or even stopping neurodegeneration in this disease.
The National Institutes of Health (NIH) estimate that around 500,000 individuals in the United States have Parkinson's disease, and that each year, about 50,000 people are diagnosed with the condition.
The illness does not have a cure yet, but researchers are hard at work trying to better understand it and design drugs that slow down the degeneration of the neurons.
Recently, scientists have been focusing on a key protein called PINK1, which is believed to have a protective role against neurodegeneration.
Earlier this year, researchers at the University of Dundee in Australia examined the role of PINK1, in the hope that it would "lead to the development of new drugs which could be designed to 'switch on' PINK1 to the benefit of patients with Parkinson's."
Now, researchers from the same university — in collaboration with scientists at the University of Cardiff in the United Kingdom — may have found such a drug.
The team was led by Dr. Youcef Mehellou, from the University of Cardiff's School of Pharmacy and Pharmaceutical Sciences, and Dr. Miratul Muqit, who is a consultant neurologist at the MRC Protein Phosphorylation and Ubiquitylation Unit in the School of Life Sciences at the University of Dundee.
They show that a drug normally used to treat tapeworm infections may bring us closer to halting Parkinson's-related neurodegeneration.
Erica Barini is the first author of the paper, and the findings have now been published in the journal iChemBioChem.
Tapeworm drug activates protective protein
The drug is called niclosamide, and the new research shows that it contains a molecule that effectively activates the PINK1 protein.
Additionally, the study shows that the drug and its analogs can boost PINK1 performance in brain cells and neurons. "Notably," the authors write, "we detected for the first time PINK1-Parkin pathway activation in neurons and demonstrated that it can be triggered by small molecules."
Niclosamide is approved and has been used safely in humans to treat helminth, or tapeworm, infections for around 50 years. The drug is currently being trialed for treating various human cancers and rheumatoid arthritis.
Repurposing existing drugs can be a cost- and time-effective way of addressing conditions that are notoriously difficult to treat.
"Our data [suggest] that niclosamide and/or its analogs could have therapeutic benefit in slowing down Parkinson's disease," write Barini and colleagues. However, they concede, more in vivo studies in animal models of Parkinson's are required to further validate this hypothesis.
"Using [niclosamide], we demonstrate for the first time that the PINK1 pathway is active and detectable in primary neurons," the authors write.
The researchers conclude, "Our findings suggest that niclosamide and its analogs are robust compounds to study the PINK1 pathway and may hold promise as a therapeutic strategy in Parkinson's and related disorders."
"This work represents the first report of a clinically used drug to activate PINK1 and may hold promise in treating Parkinson's disease [...] This is an exciting stage of our research, and we are positive about the long-term impact it could have on patients' lives."
Dr. Youcef Mehellou
"We will now take our findings to the next level by evaluating the ability of niclosamide to treat Parkinson's disease in disease models," Dr. Mehellou adds.