Professor Zezong Gu and research team finds antioxidant properties in garlic
Aged garlic extract and one of its compounds, FruArg, may inhibit neurological damage caused by common stressors.
May. 05, 2015
Alzheimer’s and Parkinson’s, along with other neurodegenerative aging and diseases, could potentially be prevented by simple dietary measures, MU School of Medicine researchers found in March.
A research team, led by Zezong Gu, associate professor of pathology and anatomical sciences, experimented with aged garlic extract and documented its effects on the brain’s immune cells in the presence of stress. Brain-damaging stressors could be pollution, brain injury, alcohol consumption or the aging process.
Other studies on garlic have focused mainly on the sulfuric component of the nutrient, which gives its potent taste and smell, as a source of an antioxidant and anti-inflammatory agent. Gu’s research focuses on the preservative responses from a carbohydrate derivative of arginine amino acid from garlic called FruArg. The report was published in the peer-reviewed online publication, PLOS ONE.
The tests involved microglial cells, immune cells in the brain and spinal cord that are the first line of defense in the central nervous system, according to the news release the MU School of Medicine posted March 26. They respond to an injury or stress and are able to multiply quickly. However, the response increases the levels of their emitted nitric oxide, which can lead to cell damage and stimulates neurodegeneration.
For those with no background in technical biological jargon, here’s a layperson’s perspective. Many things cause stress in the body, including eating, exercise and disease. This causes the microglial cells in the brain to react and possibly over-oxidate and cause damage. This study shows that garlic extract and FruArg can reduce the number of oxygen species produced and reduce the stress level. The hypothesis, then, is that if the stress can be reduced, something can be done about the onset of stress-related diseases in the brain and elsewhere.
Grace Sun, MU professor of biochemistry with a focus in oxidative stress, provided the team with the microglial cells.
“We used immortalized microglial cells and isolated them for testing,” Sun said. “We are very happy with these cells.”
The team put the cells in a culture dish and simulated stress by adding an endotoxin called lipopolysaccharide. This activated the microglia’s production of reactive oxygen species, a natural response as part of the body’s redox system, a biological system of reduction and oxidation to maintain homeostasis, or balance, in the cells. Aged garlic extract and FruArg compounds were then added and tracked to see what proteins of the stressed system were changed through mapping the molecular pathways.
“We are expecting FruArg and aged garlic extract to help manage the redox systems,” Gu said.
Pathway analysis found that around 70 percent of the protein concentrations that changed were the same between aged garlic extract and FruArg and had an antioxidant property. With the help of FruArg and the extract, stress-response systems may be controlled and reduce damage from too much oxidization, which is linked to Parkinson’s, Alzheimer’s and other neurodegenerative conditions.
“The conclusion becomes that a lot of the same proteins changed by the extract are changed by the FruArg,” said Michael Greenlief, director of the MU Proteomics Center. “That means FruArg seems to be changing the stress reaction systems and is a useful component in garlic.”
The next step is learning how to implement the research into a dietary recommendation, Gu said.
“If it all pans out, a garlic supplement could be a good thing,” Greenlief said.
Individuals and families affected by neurodegeneration, then, may soon find some control in their increasingly devastating situations. According to the Alzheimer’s Association website, every 67 seconds someone is diagnosed with the disease in the U.S. Alzheimer’s involves damage to the 100 billion nerve cells of the brain and interferes with connectivity, leading to increasing confusion and behavioral changes.
Each year, Parkinson’s disease, the damage of dopamine-producing cells in the brain, is diagnosed to 50,000 to 60,000 new cases, according to the National Parkinson Foundation website.
“What we are doing is really a public interest study,” Gu said.
Gu and his team are also encouraged by the unique structure and efficiency of their research plans.
“The exciting part is that we are using ‘systems biology,’ or looking across an entire line of proteins in the cells to find the more predominant actions of the compounds,” Gu said. “Previous studies looked for a single pathway under a defined hypothesis. Ours is a broader and unbiased look into the interactions of multiple pathways.”
The “actions” Gu refers to are what is believed to have a healing effect, though Gu said there needs to be more research. According to Gu, this study is fundamental and has more opportunity for growth.
Future experimentation with aged garlic extract and FruArg may also be extended to other areas of the body as similar studies of immune responses. Gu and his colleagues intend to study the nutrient’s properties in relation to cancer, inflammation and diabetes among other conditions.
Much of the funding and support for the work, and future developments, comes from the National Institutes of Health. A grant from the National Center for Complementary and Alternative Medicines, the Office of Dietary Supplements, and the National Cancer Institute assisted funding as well.