Biochemical link between nicotine and protein plaques
Published 13 November 2007
Researchers at the Scripps Research Institute have discovered that a by-product of nicotine, called nornicotine, appears to prevent the abnormal build-up of APP associated with Alzheimer's disease.
Amyloid plaques are toxic to brain nerve cells and are one of the hallmarks of Alzheimer's disease seen under the microscope at post mortem.
Previous research suggested that cigarette smoking may delay the onset of Alzheimer's disease but the neuroprotective effect was always unclear.
The researchers suspected that nornicotine may contribute to the neuroprotection and they have confirmed this chemically in the test-tube. The research has not been undertaken on brain cells, and it is important to note that nornicotine is toxic.
The Alzheimer's Society welcomes this research as it adds to our understanding of amyloid plaques in Alzheimer's disease. It also points the way forward to future research. For example, researchers could now look for related non-toxic compounds that mimic the action of nornicotine.
This research does not provide evidence that smoking has any protective effect for Alzheimer's disease. Other recent research has shown that smoking increases the risk of Alzheimer's disease and vascular dementia by increasing the amount of free radicals in the body, which causes damage to brain and body cell functions and damages immunity.
For more information
'Glycation of the amyloid beta-protein by a nicotine metabolite: a potentially fortuitous chemical dynamic between smoking and Alzheimer's disease' by Tobin J Dickerson and Kim D Janda, Scripps Research Institute, La Jolla USA, published in Proceedings of the National Academy of Sciences of the United States (http://www.pnas.org/)
