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Groene thee tegen de ziektes Parkinson en Alzheimer*
Uit een Duitse laboratoriumstudie blijkt dat bioactieve cathechinen als EGCG uit groene thee de vorming van plaques in de hersenen kan voorkomen. De ziektes als Alzheimer en Parkinson ontstaan doordat bepaalde eiwitten zich verkeerd uitvouwen wat op den duur tot de gevaarlijke plaquesvorming kan leiden. 
Green Tea Prevents Deathly Plaque Formation In Parkinson's And Alzheimer's - First Results In The Test Tube And With Cell Models
The substance ECGC (Epigallocatechin-3-gallate) from green tea can redirect the deadly process which leads to the accumulation of protein aggregates in Parkinson's and Alzheimer's disease. EGCG modulates a cascade of protein misfolding in such a way that the formation of deadly plaques is interrupted, and harmless protein structures emerge instead. Researchers of the Max Delbrueck Center for Molecular Medicine (MDC) Berlin-Buch, a national research laboratory of the Helmholtz Association in Germany have made this discovery in the test tube and in cell models. The research of Dr. Dagmar Ehrnhoefer and Dr. Jan Bieschke of Professor Erich Wanker`s laboratory in Berlin-Buch has now been published in the journal Nature Structural and Molecular Biology* (http://dx.doi.org/10.1038/nsmb.1437). 
ECGC binds directly to unfolded proteins at a very early stage and thus prevents their conversion into toxic aggregates. Instead non-toxic, unstructured round aggregates of a new type are formed, presumably by an alternative folding cascade. "These new aggregates are harmless", Dr. Bieschke is convinced. He said they took an antibody which recognizes toxic aggregates. However, this antibody is unable to bind to the newly formed protein aggregates that occur after EGCG treatment. 
Now the MDC-researchers want to know exactly how ECGC interferes with the "bad" proteins. They collaborate with researchers from the neighbouring Leibniz Instititute for Molecular Pharmacology (FMP) using NMR-spectroscopy to identify the structure of the new type of aggregate. 
The misfolding of proteins is a complex, multi-step process which eventually leads to the accumulation of dangerous insoluble aggregates. These aggregates are toxic for nerve cells and cause their death. They are associated with a number of disorders, including Parkinson`s and Alzheimer`s, and also Huntington's disease. 
ECGC binds to several proteins that are causative for various protein misfolding disorders. Therefore, the MDC researchers consider ECGC or similar substances to be suitable for the development of drugs to treat neurodegenerative diseases and other amyloid diseases, connected to the formation of toxic plaques. Only in 2006, Dagmar Ehrnhoefer was able to show in Drosophila flies transgenic for Huntington's disease, that ECGC reduces the toxicity of deadly plaques. 
*Redirecting aggregation pathways: small molecule-mediated conversion of amyloidogenic polypeptides into unstructured, off-pathway oligomers
Dagmar E. Ehrnhoefer1#, Jan Bieschke1#, Annett Boeddrich1, Martin Herbst1, Laura Masino2, Rudi Lurz3, Sabine Engemann1, Annalisa Pastore2, Erich E. Wanker1*
1) Max Delbrueck Center for Molecular Medicine (MDC), AG Neuroproteomics, Robert-Roessle-Straße 10, 13092 Berlin, Germany
2) National Institute for Medical Research (NIMR), The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
3) Max-Planck-Institute for Molecular Genetics, Ihnestrasse 73, 14195 Berlin, Germany
#These authors contributed equally to the work. 
Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch 
(Juli 2008)

 

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