In early-stage laboratory experiments, the researchers identified the process which allows harmful clumps of protein to latch on to brain cells, causing them to die. They were able to interrupt this pathway using the purified extracts of EGCG from green tea and resveratrol from red wine.
The findings, published in the Journal of Biological Chemistry, offer potential new targets for developing drugs to treat Alzheimer's disease, which affects some 800,000 people in the UK alone, and for which there is currently no cure.
"This is an important step in increasing our understanding of the cause and progression of Alzheimer's disease," says lead researcher Professor Nigel Hooper of the University's Faculty of Biological Sciences. "It's a misconception that Alzheimer's is a natural part of ageing; it's a disease that we believe can ultimately be cured through finding new opportunities for drug targets like this."
Alzheimer's disease is characterised by a distinct build-up of amyloid protein in the brain, which clumps together to form toxic, sticky balls of varying shapes. These amyloid balls latch on to the surface of nerve cells in the brain by attaching to proteins on the cell surface called prions, causing the nerve cells to malfunction and eventually die.
"We wanted to investigate whether the precise shape of the amyloid balls is essential for them to attach to the prion receptors, like the way a baseball fits snugly into its glove," says co-author Dr Jo Rushworth. "And if so, we wanted to see if we could prevent the amyloid balls binding to prion by altering their shape, as this would stop the cells from dying."
The team formed amyloid balls in a test tube and added them to human and animal brain cells. Professor Hooper said: "When we added the extracts from red wine and green tea, which recent research has shown to re-shape amyloid proteins, the amyloid balls no longer harmed the nerve cells. We saw that this was because their shape was distorted, so they could no longer bind to prion and disrupt cell function.
"We also showed, for the first time, that when amyloid balls stick to prion, it triggers the production of even more amyloid, in a deadly vicious cycle," he added.
Professor Hooper says that the team's next steps are to understand exactly how the amyloid-prion interaction kills off neurons. "I'm certain that this will increase our understanding of Alzheimer's disease even further, with the potential to reveal yet more drug targets," he said.
Dr Simon Ridley, Head of Research at Alzheimer's Research UK, the UK's leading dementia research charity, which part-funded the study, said: "Understanding the causes of Alzheimer's is vital if we are to find a way of stopping the disease in its tracks. While these early-stage results should not be a signal for people to stock up on green tea and red wine, they could provide an important new lead in the search for new and effective treatments. With half a million people affected by Alzheimer's in the UK, we urgently need treatments that can halt the disease - that means it's crucial to invest in research to take results like these from the lab bench to the clinic."
The research was funded by the Wellcome Trust, Alzheimer's Research UK and the Medical Research Council.
Edwin Chen, Wellcome Trust (Jul 2016), £98,341
Stefan Kepinski, Michelle Peckham, BBSRC (Apr 2016), £461,760
David Brockwell, Sheena Radford, BBSRC (Apr 2016), £358,570
Ryan Seipke, BBSRC (Apr 2016), £340,536
Neil Ranson, Mark Harris, Ade Whitehouse, Peter Stockley, Sheena Radford, Alan Berry, Wellcome Trust (Mar 2016), £1,000,000
James Duce, Alzheimer's Society (Mar 2016), £84,834
Thomas Edwards and colleagues in the School of Chemistry, EPSRC (Feb 2016), £2,228,732
Patricija Van Oosten-Hawle, Wellcome Trust (Feb 2016), £89,900
William Hoppitt, EU (Feb 2016), £34,345
Mark Harris, Thomas Edwards, John Barr and colleagues from the School of Chemistry, Wellcome Trust (Jan 2016), £204,959
Katie Field, BBSRC (Jan 2016), £830,381
Alan Berry, Alex Breeze, Adam Nelson, BBSRC (Jan 2016), £479,490
Sarah Calaghan, Isuru Jayasinghe, BHF (Jan 2016), £52,050
Paul Knox, BBSRC (Jan 2016), £40,000
Andrew Smith, Rosetrees Trust (Jan 2016), £20,000
Richard Bayliss, Cancer Research UK (Jan 2016), £10,000
Richard Bayliss, MRC (Jan 2016), £8,000
Richard Bayliss, BBSRC (Jan 2016), £8,000
Joe Cockburn, Royal Society (Dec 2015), £14,960
Katie Field, Royal Society (Dec 2015), £14,700
Stephanie Wright, Kay Kendall Leukaemia Fund (Dec 2015), £207,286
Zahra Timsah, Royal Society (Nov 2015), £15,000
Jessica Kwok, Wings For Life Spinal Cord Research (Nov 2015), £134,981
Alan Berry, Wellcome Trust (Oct 2015), £752,365
Julie Aspden, MRC (Oct 2015), £633,020
Steve Sait, NERC (Oct 2015), £386,061
Urwin, Howard Atkinson, BBSRC (Oct 2015), £200,293
Helen Miller, ABNA Ltd (Oct 2015), £115,000
Mark Harris, Royal Society (Oct 2015), £74,000
Eric Hewitt, Andrew Macdonald, Yorkshire Kidney Research Fund (Oct 2015), £46,621
Christine Foyer, Royal Society (Oct 2015), £12,000
Dave Westhead, Bloodwise (Sep 2015), £664,109
Ade Whitehouse, Alison Ashcroft, Ian Carr, BBSRC (Sep 2015), £438,975
Shaunna Burke, Andrea Utley, Sarah Astill, Arts Council of England (Sep 2015), £80,594
Samit Chakrabarty, Ronaldo Ichiyama, Intl Foundn for Research in Paraplegia (Aug 2015), £93,000
Helen Miller, Agriculture & Horticulture Develpmnt Brd (Aug 2015), £63,560
Tim Benton, M & W MACK LTD (Aug 2015), £48,711
Eileen Ingham, John Fisher, EPSRC (Jul 2015), £1,458,439
Anastasia Zhuravleva, BBSRC (Jul 2015), £483,019
Alex O'Neill, MRC (Jul 2015), £249,822
Ade Whitehouse, Richard Foster, Cancer Research UK (Jul 2015), £201,034
Ronaldo Ichiyama, Jim Deuchars, Sue Deuchars, Wings For Life Spinal Cord Research (Jul 2015), £123,895
Helen Miller, ABNA Ltd (Jul 2015), £22,968
Martin Stacey and colleagues in FMH, MRC (Jun 2015), £426,475
Adrian Goldman, Sarah Harris, Roman Tuma, BBSRC (Jun 2015), £420,693
Elwyn Isaac, EU (Jun 2015), £238,915
Christine Foyer, BBSRC (Jun 2015), £160,401
Adrian Goldman, EU (Jun 2015), £116,331
David Brockwell, Sheena Radford, Innovate UK (Jun 2015), £113,378
Yoselin Benitez-Alfonso, EPSRC (Jun 2015), £93,672