Although the exact causes of atherosclerosis are unclear, researchers have known that the inflammation found in atherosclerosis is associated with increased levels of cellular inflammatory signals called cytokines. Plaque formation is also associated with increased levels in the aorta of a protein called NF-?B that controls the formation of these cytokines, stimulates the growth of immune cells and the accumulation of low-density lipoproteins (LDL) also known as the 'bad' cholesterol. The Penn researchers have found that aspirin lowers the amount of both cytokines in the blood stream and the NF-?B in the aorta, suggesting a potent anti-inflammatory action of the drug.
Pratic and his colleagues hypothesize that these novel effects of low-dose of aspirin are independent from its known function as blood thinner.
Aspirin directly inhibits the cycloxygenase (COX) enzyme, which allows platelets in the blood to form clots. After aspirin blocks COX, it enables this enzyme to produce powerful anti-inflammatory molecules such as lipoxins, which in turn could inhibit the formation of cytokines the very molecules that may stimulate atherosclerosis.
While Pratic recognizes more research needs to be done, aspirin could provide a potent, and inexpensive way to fight atherosclerosis. Low-dose aspirin has already been proven effective in preventing a second heart attack. There is a danger, however, taking large doses of aspirin, which can lead to gastrointestinal bleeding.
So, what constitutes a low-dose?
"Generally, we consider between 80mg and 250mg of aspirin to be 'low-dosages' about the amount you would find in children's aspirin," said Pratic. "Of course, anyone considering taking a regimen of low-dose aspirin should
Contact: Greg Lester
University of Pennsylvania School of Medicine