Enhanced anti-inflammatory effect of resveratrol and EPA in treated endotoxin-activated RAW 264.7 macrophages

Macrophages play an important role in immunogenic challenges by producing reactive oxygen species, NO and proinflammatory cytokines that can aggravate and propagate local inflammation. Multiple mechanisms regulate these inflammatory processes. NF-κB and activator protein 1 pathways are crucial in the expression of proinflammatory genes, such as TNF-α, IL-1 (α or β) and -6. Some polyphenols, which are present in beverages, vegetables and fruits, and PUFA, which are present in marine oils and fish food, possess anti-inflammatory effects in vivo and in vitro. Our aim in the present study was to assess whether polyphenols and PUFA have synergistic anti-inflammatory effects in murine macrophages in vitro. Inflammation in RAW 264.7 macrophages was induced by lipopolysaccharide at 100ng/ml. The treatments with molecules were performed by co-incubation for 19h. A NO production assay by Griess reaction, a phosphoprotein assay by Pathscan ELISA kit and gene expression analysis using the TaqMan® Low-density Array for ninety-one genes related to inflammation, oxidative stress and metabolism were performed to assess the synergistic anti-inflammatory effects of polyphenols, epigallocatechin gallate and resveratrol (Res; 2.5μg/ml), and the PUFA, DHA and EPA (30μm). Adding Res+EPA had an enhanced anti-inflammatory effect, in comparison with EPA and Res alone, leading to decreased NO levels; modulating the phospho-stress activated protein kinase/Jun N-terminal kinase (P-SAPK/JNK) level; down-regulating proinflammatory genes, such as IL, chemokines, transcription factors; and up-regulating several antioxidant genes. Therefore, this combination has a stronger anti-inflammatory effect than either of these molecules separately in RAW macrophages.