The natural molecule n-acetylcysteine (NAC), with strong antioxidant effects, shows potential benefit as part of the management for patients with Parkinson's disease, researchers say. Combining clinical evaluations of a patient’s mental and physical abilities with brain imaging studies that tracked the levels of dopamine (the lack of which is thought to cause Parkinson’s), doctors from the Departments of Integrative Medicine, Neurology, and Radiology at Thomas Jefferson University in Philadelphia showed that patients receiving NAC improved on both measures.
Current treatments for Parkinson's disease are generally limited to temporarily replacing dopamine in the brain as well as some medications designed to slow the progression of the disease process. Recently, researchers have shown that oxidative stress in the brain may play a critical role in the Parkinson's disease process, and that this stress also lowers levels of glutathione, a chemical produced by the brain to counteract oxidative stress. Studies in brain cells showed that NAC helps reduce oxidative damage to neurons by helping restore the levels of the antioxidant glutathione. NAC is an oral supplement that can be obtained at most nutrition stores and also comes in an intravenous (IV) form, which is used to protect the liver in acetaminophen overdose.
"This study reveals a potentially new avenue for managing Parkinson's patients and shows that n-acetylcysteine may have a unique physiological effect that alters the disease process and enables dopamine neurons to recover some function," said senior author Daniel Monti, MD, MBA, Director of the Myrna Brind Center of Integrative Medicine and the Brind-Marcus Center of Integrative Medicine at Thomas Jefferson University.
In this study, Parkinson’s patients who continued their current standard-of-care treatment were placed into two groups. The first group received a combination of oral and IV NAC for three months. These patients received 50 mg/kg NAC intravenously once per week and 600 mg NAC orally twice a day on the non-IV days. The second group, the control patients, received only their standard of care for Parkinson’s treatment. Patients were evaluated initially, before starting the NAC, and after three months of receiving the NAC, while the control patients were simply evaluated initially and three months later. The evaluation consisted of standard clinical measures such as the Unified Parkinson’s Disease Rating Scale (UPDRS), a survey administered by doctors to help determine the stage of disease, and a brain scan via DaTscan SPECT imaging, which measures the amount of dopamine transporter in the basal ganglia, the area most affected by the Parkinson’s disease process. Compared to controls, the patients receiving NAC had improvements of 4% to 9% in dopamine transporter binding and also had improvements in their UPDRS score of about 13%.
“We have not previously seen an intervention for Parkinson’s disease have this kind of effect on the brain,” said first author and neuro-imaging expert Andrew Newberg, MD, Professor at Sidney Kimmel Medical College at Jefferson and Director of Research at the Myrna Brind Center of Integrative Medicine. The investigators hope that this research will open up new avenues of treatment for Parkinson's disease patients.
The study was recently published in PLOS ONE.
Source: Thomas Jefferson University; June 16, 2016.