Excess iron and copper is a double–edged sword for neurons
To date, the causes of the development of Alzheimer's and Parkinson's diseases, as well as many other neurodegenerative diseases, are far from fully known. However, scientists have identified several factors stably associated with these conditions, including DNA damage by free radicals (highly active molecules that are byproducts of cellular respiration) and an increase in the concentration of copper and iron ions in certain regions of the brain.
Researchers at the University of Texas, working under the leadership of Sankar Mitra, have identified a mechanism linking these two factors together. They claim that increasing the concentration of copper or iron is a "double-edged sword" for the brain, simultaneously stimulating the production of free radicals and disrupting the work of the DNA damage repair system.
According to one of the study participants Muralidhar Hegde, the imbalance between the rate of occurrence of DNA damage and their recovery leads to the accumulation of genetic errors, which is the cause of the development of neurodegenerative diseases.
In small amounts, copper and iron are necessary for the normal functioning of the human body. Usually, excess ions of these metals bind to specialized carrier proteins and are stored for future use. But in some cases, these carrier proteins are not enough to bind all the free ions that continue to circulate in the blood and initiate reactions leading to the formation of free radicals.
Under normal conditions, special enzymes quickly repair DNA damage caused by the action of free radicals or other factors. However, the experiments conducted by the authors showed that the presence of copper and iron ions significantly reduces the activity of two of these enzymes, DNA glycosylases NEIL1 and NEIL2.
The results of testing various substances that potentially have the ability to bind iron and copper ions and protect enzymes surprised the researchers somewhat. It turned out that one of the most effective agents is a popular spice from South Asia – curcumin, known for a number of positive effects on human health.
The article Muralidhar L. et al. "Oxidative Genome Damage and Its Repair in Neurodegenerative Diseases: Function of Transition Metals as a Double-Edged Sword" is published in the April issue of the Journal of Alzheimer's Disease, volume 25, No. 1.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru
24.05.2011