Pine extract prevents heart failure damage in mice

NEW YORK (Reuters Health) - A powerful antioxidant extracted from the bark of pine trees can help prevent harmful structural changes in the heart that accompany congestive heart failure, a new study in mice shows.

Feeding the extract to old mice that had been given chemicals to accelerate aging-related changes in heart structure reversed tissue-damaging gene expression patterns, Dr. Ronald Ross Watson of The University of Arizona in Tucson and colleagues found.

"The effectiveness of Pycnogenol supplementation is a great option for many people who want an alternative to prescription medications such as beta-blockers or ACE inhibitors," Watson said in a press release accompanying the study.

Left ventricular remodeling, in which the main pumping chamber of the heart undergoes changes in shape and size that impair its ability to function effectively, is a key step in the progression of heart failure, the researchers note in their article in the journal Cardiovascular Toxicology. Pycnogenol, which is extracted from French maritime pine, has shown beneficial cardiovascular effects, including enhancement of the activity of nitric oxide, a molecule that helps the heart and blood vessels respond effectively to changing demands.

To investigate whether the extract could be beneficial in preventing cardiac remodeling as well, the researchers treated mice with a substance that blocks nitric oxide. The animals showed increases in expression of genes that produce collagen-destroying MMP molecules, while activity of collagen-producing genes was reduced, resulting in a reduction of the total amount of collagen within the heart.

When the researchers gave some of the animals Pycnogenol, however, these changes were reversed, resulting in an increase in total heart collagen content compared to mice that hadn't been given the extract.

There are a number of different mechanisms by which Pycnogenol might exert these effects, the researchers note, most likely by blocking the action of MMPs.

"We propose that a therapeutic effect of Pycnogenol may help to limit cardiac remodeling in patients predisposed to congestive heart failure -- such as in the aged," Watson and his team write. "Even so, a more thorough understanding of the underlying mechanisms Pycnogenol modulates is clearly needed."

SOURCE: Cardiovascular Toxicology, published online May 16, 2007.