Cysteamine: another potential candidate on the horizon?
Original article: Cysteamine as a novel disease-modifying compound for Parkinson’s disease: Over a decade of research supporting a clinical trial, Neurobiology of disease: July 9, 2019.
A range of evidence from preclinical studies supports the case for a clinical trial of cysteamine in people with Parkinson’s.
Cysteamine is a naturally occurring substance which helps mop up damaging free radicals in cells. It acts in different ways, mostly through reducing oxidative stress. In cells, animal studies have shown that it can protect mitochondria from toxins. It can also protect liver cells from paracetamol overdose, possibly in ways that are similar to the effects of NAC, another substance which has shown promise for Parkinson’s disease modification (see linked summaries).
The authors of this review argue that cysteamine could be a promising candidate for trialing in Parkinson’s. One of its attractive aspects is the fact that it has been tested in humans and approved for use in cystic fibrosis and pancreatic cancer. In addition, it can cross from the blood into the brain which is important if it is to be repurposed.
Specifically, preclinical studies have shown that cysteamine is neuroprotective in animal models of Parkinson’s. In addition, it acts to increase brain derived neurotrophic factor (BDNF), a substance which promotes neuronal growth.
The authors also highlight findings in an animal model of Alzheimer’s which showed improvement on behavioural tasks tapping into spatial memory and learning, suggesting that potential benefits could extend to cognition.
As any potential new drug candidate, the first step onto the clinical trials ladder would have to be a phase I trial to establish that it is safe and well tolerated in people with Parkinson’s. Open questions remain as to what sort of dose could be efficacious, and whether an international panel of experts may consider it worthy of prioritization over the many potential candidates under consideration for Parkinson’s.
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Original article: Cicchetti F, David LS, Siddu A, Denis HL. July 9, 2019. Cysteamine as a novel disease-modifying compound for Parkinson’s disease: Over a decade of research supporting a clinical trial