γ-Tocotrienol attenuates TNF-α-induced changes in secretion and gene expression of MCP-1, IL-6 and adiponectin in 3T3-L1 adipocytes.

Tocotrienols, members of the vitamin E family, have been shown to possess anti-inflammatory properties and display activity against a variety of chronic diseases, such as cancer, cardiovascular and neurological diseases. However, whether tocotrienols contribute to the prevention of inflammatory responses in adipose tissue remains to be elucidated. In this study, we examined the effects of gamma-tocotrienol, the most common tocotrienol isomer, on tumor necrosis factor-alpha (TNF-alpha)-induced inflammatory responses by measuring the expression of the adipokines, monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6) and adiponectin in 3T3-L1 adipocytes. Exposure to TNF-alpha (10 ng/ml) for 24 h increased MCP-1 and IL-6 secretion, and decreased adiponectin secretion and peroxisome proliferator-activated receptor-gamma (PPAR gamma) mRNA expression. gamma-tocotrienol effectively improved the TNF-alpha-induced adverse changes in MCP-1, 1L-6 and adiponectin secretion, and in MCP-1, IL-6, adiponectin and PPAR gamma mRNA expression. Furthermore, TNF-alpha-mediated I kappa B-alpha phosphorylation and nuclear factor-kappa B (NF-kappa B) activation were significantly suppressed by the gamma-tocotrienol treatment. Our results suggest that gamma-tocotrienol may improve obesity-related functional abnormalities in adipocytes by attenuating NF-kappa B activation and the expression of inflammatory adipokines.