Resveratrol shows metabolic benefits for obese: Study
Writing in the International Journal of Obesity, researchers from Aarhus University report that resveratrol changed the production of certain compounds called adipokines from human fat cells, and produced an anti-inflammatory effect.
The study is reported to be the first to in vitro suggest resveratrol has anti-inflammatory effects on adipokine expression and secretion in human fat tissue.
“Small interfering molecules such as resveratrol are in this matter hypothesized to possess beneficial effects and might improve the metabolic profile in human obesity,” wrote the researchers, before adding that the results need to be replicated in vivo.
Resveratrol’s rosy potential
Resveratrol, a powerful polyphenol and anti-fungal chemical, is often touted as the bioactive compound in grapes and red wine, and has particularly been associated with the so-called 'French Paradox'. The phrase, coined in 1992 by Dr Serge Renaud from Bordeaux University, describes the low incidence of heart disease and obesity among the French, despite their relatively high-fat diet and levels of wine consumption.
Interest in the compound exploded in 2003 when research from David Sinclair and his team from Harvard reported that resveratrol 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.
According to Sinclair’s findings, resveratrol could activate a gene called sirtuin1 (Sirt1 – the yeast equivalent was Sir2), which is also activated during calorie restriction in various species, including monkeys.
Since then studies in nematode worms, fruit flies, fish, and mice have linked resveratrol to longer lives. Other studies with only resveratrol have reported anti-cancer effects, anti-inflammatory effects, cardiovascular benefits, anti-diabetes potential, energy endurance enhancement, and protection against Alzheimer’s.
Metabolic syndrome
The new study sought to investigate if the compound’s anti-inflammatory benefits extended to the low-grade inflammatory state associated with obesity. This is “characterized by abnormal levels of circulating proinflammatory factors and an abnormal production of bioactive factors/adipcytokines from the adipose tissue”, explained the researchers, and these adipocytokines are “suggested to have direct implications for the development of the metabolic syndrome”.
Led by Jen Olholm from the Department of Endocrinology at Aarhus University Hospital, the researchers examined the effects of resveratrol (Cayman Chemical) on levels of adipcytokines – particularly interleukin 1beta (IL-1B) – in human adipose tissue explants.
When human fat cells were exposed to IL-1B, the researchers noted increases in the secretion of pro-inflammatory compounds, including IL6, IL8, MCP-1. However, when the cells were simultaneously exposed to resveratrol, a 16 to 36 percent reduction in the expression of these cytokines was observed.
From human cell to human being
“Our results show that resveratrol ameliorates the proinflammatory response in human adipose tissue and increases adiponectin expression changes, which is hypothetically beneficial, as adipose tissue from obese individuals with metabolic syndrome, expresses lower adiponectin levels and higher levels of proinflammatory adipokines,” wrote the researchers.
“We are aware that it is difficult to compare in vitro incubations and in vivo conditions, and especially it is difficult to know whether the concentrations used in our study are a meaningful in a clinical setting.
“It is known that orally administrated resveratrol is rapidly absorbed and then quickly metabolized, but the local concentration of resveratrol in different tissue compartments are unknown and it is also not known if glucuronidated resveratrol can be locally de-glucuronidated and thus reach a higher local concentration.
“However, the concentration used in our in vitro experiments (50 mM) is similar to most other reports on resveratrol effects in different cell types,” they added.
Source: International Journal of Obesity
Volume 34, Pages 1546-1553; doi:10.1038/ijo.2010.98
“Anti-inflammatory effect of resveratrol on adipokine expression and secretion in human adipose tissue explants”
Authors: J. Olholm, S.K. Paulsen, K.B. Cullberg, B. Richelsen, S.B. Pedersen
