Additive, antagonistic, and synergistic effects of procyanidins and polyunsaturated fatty acids over inflammation in RAW 264.7 macrophages activated by lipopolysaccharide

Objective: Macrophages play an important role in immunogenic challenges and can aggravate and propagate local inflammation. Nuclear factor-kappa B (NF-κB) and activator protein 1 pathways can regulate these inflammatory processes by modulating expression of proinflammatory genes. Bioactive molecules present in food, such as procyanidins and polyunsaturated fatty acids, possess antiinflammatory effects in vivo and in vitro. Our aim was to assess whether they have synergistic antiinflammatory effects in murine macrophages. Methods: A nitric oxide production assay, a phosphoprotein assay, and a low-density array for 91-gene expression related to inflammation, oxidative stress, and metabolism were performed to assess the synergistic antiinflammatory effects of dimeric procyanidins (B1, B2, B3, B4) (5 μg/mL), and the polyunsaturated fatty acids, docosahexaenoic acid, and eicosapentaenoic acid (30 μM) coincubated with lipopolysaccharide for 19 h to mimic inflammation in RAW 264.7 macrophages (mouse leukaemic monocyte macrophage cell line). Results: Adding eicosapentaenoic acid plus B3 had synergistic effects leading to decreased nitric oxide levels; the modulation of phosphoprotein levels, such as P-nuclear factor-[kappa] B p65 and P-stress-activated protein kinase/Jun-amino-terminal kinase; the down-regulation of proinflammatory genes, such as interleukins, chemokines, transcription factors; and up-regulation of antioxidant genes. Conclusion: This combination has a stronger antiinflammatory effect than either of these molecules separately in RAW macrophages. These results could lead to in vivo studies that may yield novel preventive or palliative nutritional treatments for obesity, atherosclerosis, and cardiovascular diseases.