Pomegranate peel polyphenols inhibits inflammation in LPS-induced RAW264.7 macrophages via the suppression of MAPKs activation

Inflammatory response remains one of the most common and serious complications of disease in clinical studies. It has been established that some molecules found in pomegranate peel polyphenols (PPPs) are related to inflammatory processes; however, the mechanisms are unclear, leaving a significant unmet medical need. The goal of this study was to analyze the anti-inflammatory effects of PPPs in RAW264.7 macrophages and examine the relationship between certain special components such as - punicalagin (PC) and ellagic acid (EA) and systemic inflammation. The results showed that PPPs and their main components PC and EA, could decrease pro-inflammatory cytokines (TNF-alpha, IL-1 beta and IL-6) at the mRNA and protein levels and, down-regulate iNOS and COX-2 expression, which in turn reduced NO and PGE(2). The molecular mechanism might be associated with the inhibition of MAPKs activation. Additionally, PPPs and PC performed much better than EA. We highlight the key role of food-derived molecules PPPs and its main components in understanding the mechanism of anti-inflammatory.