Diseases such as hypertension and heart failure can cause fibrosis, a hardening or stiffening of the heart tissue. This condition arises when heart cells called cardiac fibroblasts are activated. These cells secrete collagen, a protein that provides structural support for the heart.
Overactive cardiac fibroblasts cause fibrosis of the heart tissue, which then loses its ability to efficiently pump blood, said Joshua Bomser, a study co-author and an assistant professor of human nutrition at Ohio State University.
While resveratrol is already known for helping to prevent blood clots and also possibly reducing cholesterol, this is the first time that scientists have studied the compound's direct effects on these heart cells.
The study currently appears online on the American Journal of Physiology – Heart and Circulatory Physiology website. Bomser worked with a team of researchers from the Northeastern Ohio Universities College of Medicine, led by J. Gary Meszaros.
While the researchers can't say how much resveratrol is needed to be beneficial, previous studies suggest that drinking red wine in moderation – one or two five-ounce glasses a day – may offer protective effects. Nearly all dark red wines – merlot, cabernet, zinfandel, shiraz and pinot noir – contain resveratrol.
In the current study, treating rat cardiac fibroblasts cells with resveratrol prevented the actions of a potent hormone called angiotensin II. In the case of hypertension and heart failure, angiotensin II is produced at a high level, which is the body's way of trying to repair damage to the heart and to increase blood pressure.
But the plan usually backfires, as the hormone causes cardiac fibroblast production to go into overdrive, and, as a result, these cells produce excessive amounts of collagen – a fibrous substance found in bone, tendons, ligaments and other connective tissues.
"This hyper-secretion of collagen leads to a stiffening of the heart muscle," Bomser said. "So the heart has to work harder to pump blood, which causes further damage to the myocardium."
The researchers pretreated rat cardiac fibroblasts with resveratrol prior to adding angiotensin II to the cells. Resveratrol treatment inhibited angiotensin II's ability to cause growth and proliferation of the cardiac fibroblasts. Resveratrol also prevented these cells from turning, or differentiating, into myofibroblasts, a specialized type of fibroblast that produces large quantities of collagen.
"These results suggest that resveratrol has anti-fibrotic properties in the myocardium," Bomser said.
While the researchers can't say how much resveratrol is needed to be beneficial, previous studies suggest that drinking red wine in moderation – one or two five-ounce glasses a day – may offer protective effects. The amount of resveratrol in a bottle of red wine can vary between types of grapes and growing seasons, according to the researchers. But nearly all dark red wines – merlot, cabernet, zinfandel, shiraz and pinot noir – contain resveratrol.
This study received support from the American Heart Association – Ohio Valley Affiliate, and the Ohio Agricultural Research and Development Center.
Bomser and Meszaros conducted the study with NEOUCOM graduate students Erik Olson, Jennifer Naugle and Xiaojin Zhang.
Contact: Joshua Bomser, 614-247-6622; jbomser@hec.ohio-state.edu
Written by Holly Wagner, 614-292-8310; wagner.235@osu.edu