4'-Methoxyresveratrol Alleviated AGE-Induced Inflammation via RAGE-Mediated NF-κB and NLRP3 Inflammasome Pathway

Advanced glycation end products (AGEs) could interact with the receptor for AGE (RAGE) as a sterile danger signal to induce inflammation. 4′-methoxyresveratrol (4′MR), a polyphenol derived from Dipterocarpaceae, has not been studied for its anti-inflammation effects. In the present study, we sought to explore the protective role of 4′MR in AGEs-induced inflammatory model using RAW264.7 macrophages. 4′MR significantly inhibited gene expression of pro-inflammatory cytokines and chemokines, such as interleukin 1β (IL-1β), interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α) and monocyte chemoattractant protein-1 (MCP-1), as well as two typical pro-inflammatory enzymes, inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2). Besides, 4′MR significantly decreased oxidative stress, demonstrated by levels of ROS production, protein carbonyl and advanced oxidation protein product via down-regulation of NADPH oxidase. Further analysis showed that 4′MR attenuated the RAGE overexpression induced by MGO-BSA. It also blocked the downstream signal of AGE-RAGE, particularly, MAPKs including p38 and JNK, and subsequently reduced NF-κB activation. Additionally, 4′MR significantly abated the activation of NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome including NLRP3 and cleaved caspase-1 and reduced the secretion of mature IL-1β. Taken together, our results suggest that the anti-inflammatory effect of 4′MR is mainly through suppressing RAGE-mediated MAPK/NF-κB signaling pathway and NLRP3 inflammasome activation. 4′MR could be a novel therapeutic agent for inflammation-related diseases.