Resveratrol prevents TNFα-induced suppression of adiponectin expression via PPARγ activation in 3T3-L1 adipocytes

Tumor necrosis factor alpha (TNF alpha) is an adipokine, whose increase is known to suppress the expression and secretion of adiponectin in adipocytes. Resveratrol has been ever reported to recover the suppression of adiponectin by TNF alpha, but the underlying mechanism remains poorly understood. In this study, we validated the roles of resveratrol in the inhibition of the adiponectin by TNF alpha in 3T3-L1 cells. Exposure to TNF alpha for 24 h inhibited adiponectin synthesis and secretion, but the inhibitions were partially recovered by resveratrol treatment in 3T3-L1 adipocytes. Furthermore, we found that resveratrol improved the expression of adiponectin by the increase of PPAR gamma DNA-binding activity. Our results suggest that resveratrol may attenuate the inhibition of adiponectin expression by TNF alpha via activation of PPAR gamma, thereby possibly improving insulin resistance. However, significant preventive effects of resveratrol were only observed when it was administrated before TNF alpha increase, limiting its use as preventive strategy for insulin resistance.