HEALTH NEWS

Study Title:

Resveratrol Lowers Inflammation and Free Radical Production in Humans

Study Abstract

Background: Resveratrol have been shown to exert an antiinflammatory and antiaging effects in vitro and in animal models.

Objective: The objective of the study was to investigate the effect of a Polygonum cuspidatum extract (PCE) containing resveratrol on oxidative and inflammatory stress in normal subjects.

Research Design and Methods: Two groups (10 each) of normal-weight healthy subjects were randomized to placebo or PCE containing 40 mg resveratrol daily for 6 wk. Fasting blood samples were obtained prior to and after treatment at 1, 3, and 6 wk. Mononuclear cells were prepared for reactive oxygen species generation, RNA isolation, nuclear extract, and total cell homogenate preparation. Indices of oxidative and inflammatory stress, suppressor of cytokine signaling-3, phosphotyrosine phosphatase-1B, jun-N-terminal kinase-1, and inhibitor of B-kinase- were measured by RT-PCR and Western blotting.

Results: The extract induced a significant reduction in reactive oxygen species generation, the expression of p47phox, intranuclear nuclear factor-B binding, and the expression of jun-N-terminal kinase-1, inhibitor of B-kinase-, phosphotyrosine phosphatase-1B, and suppressor of cytokine signaling-3 in mononuclear cells when compared with the baseline and the placebo. PCE intake also suppressed plasma concentrations of TNF-, IL-6, and C-reactive protein. There was no change in these indices in the control group given placebo.

From press release:

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 IKKβ), 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.”

Comprehensive effect

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.

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.

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.”

Study Information

Husam Ghanim, Chang Ling Sia, Sanaa Abuaysheh, Kelly Korzeniewski, Priyanka Patnaik, Anuritha Marumganti, Ajay Chaudhuri, and Paresh Dandona
An Antiinflammatory and Reactive Oxygen Species Suppressive Effects of an Extract of Polygonum Cuspidatum Containing Resveratrol
Journal of Clinical Endocrinology & Metabolism
2010 June
Division of Endocrinology, Diabetes, and Metabolism, State University of New York at Buffalo and Kaleida Health, Buffalo, New York 14209