Anti-inflammatory effect of resveratrol on adipokine expression and secretion in human adipose tissue explants

Abstract

Human obesity is closely associated with a state of chronic low-grade inflammation, which also involves the adipose tissue with enhanced production of bioactive substances (adipokines). Calorie restriction (CR) reduces adipocytokine production and improves metabolic profile in rodents. Some of these effects are mediated through activation of the sirtuin 1 (Sirt1) enzyme, and in this study, we investigate whether the natural phytoalexin, resveratrol (RSV), which is a potent Sirt1 activator, has anti-inflammatory effects in human adipose tissue explants. The effect of RSV on interleukin 1β (IL1β)-induced change of adipokine mRNA gene expression and secretion were measured in human adipose tissue explants. Exposure of human adipose tissue in vitro to IL1β for 24 h increased secretion of the proinflammatory adipokines IL6, IL8 and monocyte chemoattractant protein 1 (MCP-1) 3-7.7-fold (P<0.05) and increased IL6, IL8, MCP-1, IL1β and PAI-1 mRNA expression 1.3-7.2-fold (P<0.05) accordingly. Concomitant incubations with RSV reversed the IL1β-stimulated secretion (16-36%) and gene expression (25-48%) of these adipokines. IL1β reduced adiponectin mRNA expression (40%), a decrement that was reversed by RSV treatment. Similar effects were observed in differentiated human preadipocytes in primary culture, indicating that human adipocytes are a potential target for RSV effects. Finally, the effects were neutralized by sirtinol, a Sirt1 inhibitor. This study is the first to show anti-inflammatory effects of RSV on adipokine expression and secretion in human adipose tissue in vitro through the SIRT1 pathway. Thus, RSV is hypothesized to possess beneficial effects and might improve the metabolic profile in human obesity.