Studies Show Genetic Activity of Antioxidants

July 22 -- TUESDAY, July 21 (HealthDay News) -- Using the latest genetic technology, researchers have begun to discover the exact molecular reasons why foods such as turmeric -- a popular curry spice -- and ordinary orange juice are good for the health of hearts and arteries.

Two French research teams are reporting studies describing the range of genes that are affected by curcumin, the active ingredient in turmeric, and hesperidin, an antioxidant that is a prominent component of orange juice. Their reports were delivered at the American Heart Association's Basic Cardiovascular Sciences Conference 2009, held in Lake Las Vegas.

"We used a microarray approach," said Dragan Milenkovic, a research scientist at the Centre de Clermont-Ferrand/Thiex in Saint Genes Champanelle, who described the turmeric study. "We have slides with samples of all the genes and we compared the expression of each gene to see which of them had their activity modified by exposure to curcumin."

The molecular study was done with mouse genes, and was preceded by a trial in living mice. The researchers used curcumin, which is a polyphenol, a form of antioxidant. Like other antioxidants, curcumin is known to help prevent against arterial buildup of plaque, the fatty deposits that eventually can block blood vessels.

The molecular study was preceded by a trial in which mice given a daily curcumin supplement for 16 weeks were found to have a 26 percent lower level of fat deposits in the aorta, the main artery of the heart.

The researchers then isolated genetic material from the mice and exposed it to curcumin. They found altered expression of 2,252 genes, whose activity included cellular signaling and adhesion, inflammation and fat metabolism.

The orange juice study was done by a different team of researchers at the same institute, in human volunteers. Twenty-four men who were healthy overall but who had cardiovascular risk factors such as obesity took part. In three one-month periods, the men drank one of three drinks a day: 500 milliliters of orange juice (containing 292 milligrams of hesperidin), 500 milliliters of an energy drink, or 500 milliliters of the same drink enriched with 292 milligrams of hesperidin.