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Piceatannol is a hydroxylated derivative of resveratrol. While both dietary polyphenols coexist in edible plants and fruits, and share equivalent concentrations in several wines, the influence of piceatannol on adiposity has been less studied than that of resveratrol. Though resveratrol is now recognized to limit fat deposition in various obesity models, the benefit of its dietary supplementation remains under debate regarding human obesity treatment or prevention. The research for more potent resveratrol analogs is therefore still undergoing. This prompted us to compare various effects of piceatannol and resveratrol directly on human adipose tissue (hAT). Hydrogen peroxide release was measured by Amplex Red-based fluorescence in subcutaneous hAT samples from obese patients. Interactions of stilbenes with human amine oxidases and quinone reductase were assessed by radiometric methods, computational docking and electron paramagnetic resonance. Influences on lipogenic and lipolytic activities were compared in mouse adipocytes. Resveratrol and piceatannol inhibited monoamine oxidase (MAO) with respective IC 50 of 18.5 and 133.7 μM, but not semicarbazide-sensitive amine oxidase (SSAO) in hAT. For both stilbenes, the docking scores were better for MAO than for SSAO. Piceatannol and resveratrol similarly hampered hydrogen peroxide detection in assays with and without hAT, while they shared pro-oxidant activities when incubated with purified quinone reductase. They exhibited similar dose-dependent inhibition of adipocyte lipogenic activity. Only piceatannol inhibited basal and stimulated lipolysis when incubated at a dose ≥100 μM. Thus, piceatannol exerted on fat cells dose-dependent effects similar to those of resveratrol, except for a stronger antilipolytic action. In this regard, piceatannol should be useful in limiting the lipotoxicity related to obesity when ingested or administered alone – or might hamper the fat mobilization induced by resveratrol when simultaneously administered with it. [ABSTRACT FROM AUTHOR]

Stilbenes contained in various foods are associated with health beneficial effects. In this study six natural and one synthetic stilbene were tested for their potential to regulate the activity of lipoxygenase and cyclooxygenasein vitro. The most potent inhibitor of 5-lipoxygenase was pterostilbene (IC50= 9.32 μM), whereas the strongest inhibitor of cyclooxygenase-1 and cyclooxygenase-2 was pinostilbene (IC50s= 1.90 and 0.35 μM, respectively). Pterostilbene (IC50s= 11.70 and 27.04 μM for cyclooxygenase-1 and cyclooxygenase-2, respectively) and oxyresveratrol (IC50s= 18.49; 2.79 and 14.71 μM for 5-lipoxygenase, cyclooxygenase-1, and cyclooxygenase-2, respectively) were capable to inhibit catalytic activity of all three tested enzymes. Isorhapontigenin (IC50s= 8.81 and 24.00 μM for cyclooxygenase-1 and cyclooxygenase-2, respectively) and rhapontigenin (IC50s= 24.55 and 36.12 μM for cyclooxygenase-1 and cyclooxygenase-2, respectively) were only moderate or weak inhibitors of both cyclooxygenase forms. In summary, these results indicated that besides the known cyclooxygenase inhibitor resveratrol also other natural stilbenes could be potent inhibitors of the arachidonic acid pathway and deserve further attention as compounds with promising health benefits. [ABSTRACT FROM PUBLISHER]