These 2 compounds are among the most studied antioxidant phenolic compounds. Beneficial effects of resveratrol were first described in 1982 with various functions attributed to it including antioxidant, anti-inflammatory, anti-diabetic, anti-carcinogenic, and immunomodulating functions. Resveratrol has been shown to have anti-obesity functions via the reduction of fat through mechanisms including food intake modulation, regulation of the cell cycle of adipocytes, modification of nutrient absorption, regulation of mitochondrial function, induction of thermogenesis, modulation of intestinal microbiota, and reduction in adipose tissue inflammation. Many biological functions have also been attributed to quercetin such as anti-inflammatory, anti-diabetic, anti-atherosclerotic, anti-hypertensive, anti-hypercholesterolemic, and anti-obesity functions.
This study demonstrates certain metabolites of resveratrol and quercetin molecules which remain following their digestion remain biologically active and contribute in part to the anti-obesity effect of these compounds.
“The results obtained show that all the metabolites from resveratrol contribute to the same degree as the polyphenol toward inhibiting adipogenesis. Although they are active in mature adipocytes, resveratrol is much more effective. In the case of quercetin, this effect can only be attributed to the sulphated metabolite (quercetin-3-0-sulphate) in mature adipocytes, since none of the quercetin metabolites turned out to be as effective as or more effective than the polyphenol on its own in inhibiting adipogenesis,” explained Eseberri-Barace in her Ph.D thesis. “It can therefore be concluded that the metabolism of these two compounds can signify a limitation only in the case of mature adipocytes treated with resveratrol and pre-adipocytes in differentiation treated with quercetin.”
“The amounts of resveratrol and quercetin used in most of the in vitro studies conducted to date for the purpose of studying their effects as anti-obesity molecules are a long way from those that actually reach the tissue, so the use of doses closer to reality has been one of the novel aspects of this work,” said Itziar Eseberri. “What is more, very few studies have been conducted to check whether the metabolites derived from the metabolism of the two polyphenols have any biological activity on a par with the parent compound.”
Eseberri-Barace’s thesis experiments analysed whether the main metabolites of the compounds in 3T3-L1 adipocytes could be responsible for and/or contribute to fat reduction attributed to quercetin and resveratrol; as well as checking and comparing the action mechanisms responsible for the antiobesity effect of each molecule in adipocytes in culture. Eseberri-Barace’s thesis experiments have led to 5 published scientific papers which have shown certain metabolites of both molecules are biologically active and partly contribute towards the anti-obesity effects.
“There has been partial confirmation of the hypothesis that determines whether the beneficial triglyceride-lowering effects of resveratrol and quercetin can be attributed to them alone or to their principal metabolites, as well. Metabolism should not be regarded as a limitation in the case of either resveratrol in pre-adipocytes in differentiation, or in quercetin in mature adipocytes,” concluded Eseberri-Barace.
