The company's dietary supplement contains muscadine grape seeds, which are said to have high levels of both antioxidant and anti-inflammatory compounds.
As part of the study, the researchers are evaluating the influence of the supplement on blood vessel function in 50 participants at Wake Forest University in Winston-Salem, North Carolina.
The results could be of interest to formulators looking to market grape seed products for heart health.
"The goal of the current study is to determine if daily doses of the Nature's Pearl supplement, which is specially prepared to maximize its natural antioxidant and anti-inflammatory concentrations, will have a favorable effect on cardiovascular risk factors," said David Herrington, lead investigator and professor of cardiology at Wake Forest.
Grapes skins and grape seed in general have high antioxidant content, but muscadine grapes in particular have been shown to be more potent in antioxidants than other varieties - especially their seeds.
Nature's Pearl also boasts a high concentration of plant-derived active compounds, including gallic acid, ellagic acid, oligomeric proanthocyanidins and resveratrol.
These are associated with reducing oxidative stress.
"Cardiovascular disease is a significant problem in this country so it is worthwhile to examine foods that may have medicinal benefits," said Herrington.
"In this case, our goal is to determine whether the Nature's Pearl supplement, which looks promising because of its extremely high antioxidant and anti-inflammatory content, will positively affect artery health."
The participants include patients between the ages of 18 and 65 years old with a cardiovascular disease, or a high risk of developing it.
They have been recruited and the results are expected to be analyzed in early 2008.
The patients have been randomly assigned to take either 1,300mg (or two capsules of Nature's Pearl muscadine grape seed supplement) daily or a placebo for the first four weeks of the study.
This is followed by a four-week 'wash out' period, and a switch: the group who took the placebo originally will take a supplement and vice versa.
Researchers will then use ultrasound technology to determine blood vessel function.
According to the scientists, blood flow in the brachial artery, the major vessel in the arm, is measured both before and after arteries are constricted with a blood pressure cuff.
Among healthy subjects, an artery dilates after constriction, whereas less reactivity is thought to be a sign of reduced artery function and to be a precursor to the atherosclerosis that can lead to heart attack or stroke.
The study will measure any effects on total cholesterol, low-density lipoprotein or "bad" cholesterol, triglycerides, high-density lipoprotein or "good" cholesterol, blood sugar levels and markers for inflammation, such as C-reactive protein and interleukin-6.