One of the many ways scientists are working to unravel the mysteries of Alzheimer's is by conducting experiments on mice that have been genetically engineered to develop the disease. Researchers pondering the protective potential of compounds found in green tea and carrots have again taken this route and returned some promising results, with the Alzheimer's mice demonstrating unimpaired cognitive function following a carefully designed bout of treatment.
The research was carried out by medical scientists at the University of Southern California and involved a pair of compounds found in green tea and carrots. The first is ferulic acid, or FA, an antioxidant found in carrots rice and tomatoes that has shown potential in this area. The other is called epigallocatechin-3-gallate, or EGCG, and is a key ingredient in green tea that has shown promise in research projects aiming to develop Alzheimer's treatments, better protect teeth, deliver cancer-killing drugs and even prevent heart attacks.
"We had previously shown that each of these compounds on their own could reduce Alzheimer's changes in brains of mice genetically programmed to develop the disease," senior author on the study Terrence Town tells New Atlas.
Town and his colleagues designed a study to see how the two work might work in tandem to treat Alzheimer's. Thirty-two mice with Alzheimer's-like symptoms were enlisted for the experiment and divided into four groups with the males and females split evenly, while healthy mice were also thrown into each group for the sake of comparison.
Over a period of three months, one group was fed a combination of EGCG and FA, one group was fed EGCG alone, another FA alone and the final group a placebo. The compounds were administered in dosages of 30 milligram per kilogram of body weight, which the scientists say is in line with what a human would consume as part of a healthy diet.
The mice were put through neurophysiological tests before and after the regime, and by observing changes in their behavior the scientists were able to tease out some useful insights. These exercises are claimed to be more or less analogous to those used to test thinking and memory capacity in human dementia patients, and the most fruitful of them was a spatial working memory test using a Y-shaped maze.
Where healthy mice are able to explore each arm of the Y maze on the hunt for food or an escape in a well-reasoned manner, impaired mice soon become disoriented. The special diet, however, seemed to put their performance back on par, completely restoring their spatial working memory and enabling them to perform just as well as the healthy mice. The Alzheimer's mice performed better in other tests, too.
"We conducted a battery of cognitive tests and found reversal of other cognitive aspects, such as reduced anxiety-like behavior in an open field and remediated spatial reference memory in a radial arm water maze," Town tells us.
While scientists don't know exactly why this happened, they have some ideas. The buildup of brain plaque called amyloid beta is commonly associated with the onset of Alzheimer's and indeed countless research projects have probed these toxic proteins in hope of uncovering new ways to treat or even reverse the disease. The scientists suspect these natural compounds may be intervening in their accumulation.
"One mechanism appeared to be the substances' ability to prevent amyloid precursor proteins from breaking up into the smaller proteins called amyloid beta that gum up Alzheimer patients' brains," Town says. "In addition, the compounds appeared to reduce neuroinflammation and oxidative stress in the brain – key aspects of Alzheimer's pathology in humans."
It is currently unknown how these results will translate to humans, if at all. And though treating Alzheimer's certainly isn't as simple as drinking more tea or eating more carrots, the scientists are buoyed by the study because they say it sheds more light on the role a healthy diet might play in its onset. They will now continue investigating other plant-derived compounds that can also block the buildup of the amyloid beta plaques, in hope of working toward combination therapies that can stave off its effects.
"You don't have to wait ten to 12 years for a designer drug to make it to market; you can make these dietary changes today," says Town. "I find that very encouraging."
The research was published in the Journal of Biological Chemistry.
Source: University of South Carolina
