Piceatannol affects fatty acid mobilization during isoproterenol-induced lipolysis in pig precision-cut adipose tissue slices

Piceatannol, a stilbene structurally close to resveratrol, was previously shown to reduce lipolysis in mouse adipocytes both in vitro and in vivo. Here, we investigated the effects of both resveratrol and piceatannol on pig precision-cut adipose tissue slices stimulated with isoproterenol, a beta-adrenergic receptor agonist. Neither polyphenol affected glycerol release by adipocytes when applied at 10 or 100 μM. However, both compounds appeared to reduce glycerol release at 1 mM, suggesting a potential lowering effect on triglyceride hydrolysis at high concentrations. Since polyphenols may react with hydrogen peroxide, a by-product of the glycerol assay, we evaluated potential interferences with the assay. We found a dose-dependent reduction of the dye production by both polyphenols at 50 μM and above, particularly strong in the case of piceatannol. To circumvent this interference, we quantified the production of free fatty acids using gas chromatography-flame ionization detection in isoproterenol-stimulated precision cut adipose tissue slices, as free fatty acid levels are expected to increase concomitantly with glycerol release during the hydrolysis of triglycerides. Analysis confirmed that piceatannol at 1 mM significantly reduced fatty acid release from adipocytes in isoproterenol-stimulated precision cut adipose tissue slices. In contrast, resveratrol effects were no longer significant. In conclusion, this study shows that high concentrations of piceatannol, but not resveratrol, influence fatty acid mobilization in a distinct species and in vitro model. It also highlights the interferences of polyphenols with enzymatic kits commonly used to assess lipolysis, emphasizing the importance of validating such observations through gas chromatography-based free fatty acid analysis.