Resveratrol (grape extract) shown to suppresses inflammation, free radicals in humans

August 3, 2010

in Health News,Studies

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New research has observed the suppressive effects of resveratrol on inflammation and oxidative stress in humans – the first time such effects have been observed.

Oxidative stress and chronic inflammation are part of the root causes of many diseases such as cardiovascular diseases, insulin resistance, auto-immune diseases like rheumatoid arthritis, and Alzheimer’s disease.

The new study, published early online in the Journal of Clinical Endocrinology and Metabolism, investigated the effects of resveratrol-containing Polygonum cuspidatum extract (PCE) on oxidative stress and inflammation, by measuring its suppressive effect on reactive oxygen species (ROS) generation and a range inflammatory mediators.

The study, led by Prof. Paresh Dandonda from the University at Buffalo, suggests that resveratrol may reduce oxidative stress and inflammation through increased expression of anti-inflammatory cytokines, and a reduction in pro-inflammatory molecules.

“These comprehensive suppressive effects on ROS generation and inflammation are consistent with an anti-aging action of resveratrol” wrote the researchers.

…observations suggest a potent anti-inflammatory effect of PCE containing resveratrol.”

Promise of long life

Resveratrol, a powerful polyphenol and anti-fungal chemical, is often suggested to be the bioactive compound in grapes and red wine.

Interest in resveratrol exploded in 2003 when research from David Sinclair and his team from Harvard reported that it was able to increase the lifespan of yeast cells. The research, published in Nature, was greeted with international media fanfare and ignited flames of hope for an anti-ageing pill.

Since then studies in nematode worms, fruit flies, fish, and mice have all linked resveratrol to longer lives. Other studies on resveratrol have reported anti-cancer effects, anti-inflammatory effects, cardiovascular benefits, anti-diabetes potential, energy endurance enhancement, and protection against Alzheimer’s.

Inflammatory effects

The aims of the new study were to investigate the effect of PCE on oxidative and inflammatory stress in normal human subjects. The researchers wrote: “There is data showing the anti-inflammatory effects [of resveratrol] in vitro, but there is no data demonstrating this in humans”

In the study, 20 healthy participants were randomized to receive placebo or PCE (containing 40mg resveratrol) over a six week period.

Researchers observed that the resveratrol rich PCE suppressed reactive oxygen species generation, and also suppressed binding of the pro-inflammatory cytokine NFkB. The study also saw a significant reduction in the expression of tumor necrosis factor-alpha and interleukin-6, two major pro-inflammatory cytokines that are regulated by NFkB.

In parallel to these effects, the study witnessed a reduction in the expression of two major pro-inflammatory molecules (JNK-1 and IKK?), leading to an anti-inflammatory response. The study also saw a reduction in the expression of SOCS-3, a protein that is modulated by pro-inflammatory cytokines.

“The observations suggest a potent anti-inflammatory effect of PCE containing resveratrol.” said the researchers.

Comprehensive effect

The results demonstrated in the research are the first time that such findings have been seen in humans, but are consistent with potential antiatherogenic and antiaging effects of resvertatrol. Concluding that PCE “has a comprehensive suppressive effect on oxidative and inflammatory stress.”

Prof. Dandona said that whilst the results of the study are promising, one drawback is that the research did not eliminate the possibility that something other than resveratrol was responsible for the observed anti-inflammatory response from PCE.

“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. These agents could be even more potent than resveratrol. Purer preparations now are available and we intend to test those.”

The authors state that “Longer term studies are required to determine whether these effects are durable and whether higher doses will produce a greater effect.”

Source: Journal of Clinical Endocrinology and Metabolism

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