TNF and obesity due to melanocortin 4 receptor deficiency: In a co-culture system using 3T3-L1 adipocytes and RAW264 macrophages, luteolin (20 μM) was found to inhibit JNK activation and block proinflammatory factor expression (TNF-α, MCP-1 and NO), thereby playing a major role in the regulation of adipose tissue inflammation and IR in obesity.40