"Resveratrol has been shown to exert an anti-inflammatory and anti-oxidative stress effect in vitro and in animal models," Husam Ghanim, PhD and colleagues write. "Resveratrol has also been shown to prolong life expectancy and to reduce the rate of aging in the yeast and lower animals like yeast, Caenorhabtidis elegans and Drosophila. Resveratrol actions are thought to be mediated by increased expression of sirtuin-1 (SIRT-1), a gene associated with longevity."
Twenty healthy participants were randomized to receive Polygonum cuspidatum extract containing 40 milligrams resveratrol per day or a placebo for 6 weeks. Blood samples collected at the beginning at the trial and at 1, 3 and 6 weeks were analyzed for indices of oxidative and inflammatory stress in addition to other factors. "Since there are no data demonstrating the effect of resveratrol on oxidative and inflammatory stress in humans, we decided to determine if the compound reduces the level of oxidative and inflammatory stress," explained senior author Paresh Dandona, MD, PhD, who is a distinguished professor of medicine at the State University of New York at Buffalo. "Several of the key mediators of insulin resistance also are pro-inflammatory, so we investigated the effect of resveratrol on their expression as well."
The research team found a reduction in reactive oxygen species, which are unstable molecules that provoke oxidative stress and inflammation, in participants who received resveratrol. The resveratrol group also experienced a decrease in the inflammation protein tumor necrosis factor-alpha (TNF-alpha) as well as inflammation markers interleukin-6 and C-reactive protein (CRP). In addition, intranuclear binding of nuclear factor kappa-beta, the major pro-inflammatory cytokine, was suppressed. "These actions, demonstrated for the first time, in vivo, are consistent with potential anti-atherogenic and anti-aging effects," the authors write.
"The product we used has only 20 percent resveratrol, so it is possible that something else in the preparation is responsible for the positive effects," Dr Dandona noted. "These agents could be even more potent than resveratrol. Purer preparations now are available and we intend to test those."
