Low doses of carbon monoxide may protect against neurodegeneration and prevent the accumulation of a key protein associated with Parkinson’s disease.
- Smoking may be associated with a reduced risk of Parkinson’s disease.
- It is the carbon monoxide present in cigarette smoke that prevents the accumulation of a protein linked to Parkinson’s.
- But this effect was only observed with low doses of carbon monoxide.
“Paradoxically, smoking is associated with a reduced risk of Parkinson’s disease.” This was reported by researchers from Massachusetts General Hospital in Boston, USA, in a study published in the journal npj Parkinson’s Diseaseso they hypothesized that some elements present in cigarette smoke, notably carbon monoxide levels that are modestly elevated in smokers, could contribute to neuroprotection. To test this theory, the scientists conducted an experiment on rodents with Parkinson’s disease based on α-synuclein (αSyn) accumulation and oxidative stress. They administered a low dose of carbon monoxide, comparable to the exposure experienced by smokers, in the form of an oral medication.
Parkinson’s: Low dose of carbon monoxide attenuates neurodegeneration
The results showed that low doses of carbon monoxide protected rodents against key features of Parkinson’s disease, including loss of dopaminergic neurons and accumulation of alpha-synuclein in neurons, a protein associated with Parkinson’s disease. Specifically, oral administration of low-dose carbon monoxide activated signaling pathways mediated by heme oxygenase-1 (HO-1), a stress-induced enzyme that produces endogenous carbon monoxide. The activated signaling pathways are involved in limiting oxidative stress and degrading αSyn.
The importance of heme oxygenase-1 levels in cerebrospinal fluid and neurons
The authors also found that heme oxygenase-1 levels were higher in the cerebrospinal fluid of smokers than in nonsmokers. Additionally, in brain tissue samples from patients with Parkinson’s disease, heme oxygenase-1 levels were higher in neurons that did not have alpha-synuclein pathology. “These data suggest that molecular pathways activated by low-dose carbon monoxide may slow the onset and limit the pathology of Parkinson’s disease. They warrant continued research into low-dose carbon monoxide and the pathways it alters to slow disease progression in PD,” concluded the authors.
