Synthesis and in vitro characterization of naproxen derivatives as novel anti-inflammatory agents

Naproxen, one type of non-steroidal anti-inflammatory drugs, has excellent anti-inflammatory activity. However, long-term use of it causes serious adverse effects. Inspired by the biological diversification of cinnamic acid, novel naproxen derivatives containing cinnamic acid are synthesized and used to improve their anti-inflammatory activity and safety. Our results indicated that thirty naproxen derivatives have different inhibitory effects on RAW264.7 macrophage cells. It is showed that most of the target naproxen derivatives possess the lower degree of cytotoxicity than that of naproxen. Further studies indicated that compound 22 (IC50 = 8.74 ± 2.13 μM) concentration-dependently inhibits the over-expression of iNOS, COX-2 and IL-1β by blocking the activation of nuclear factor kappa-B (NF-κB) signaling pathway and NLRP-3 inflammasome, respectively. Docking studies showed that the binding of compound 22 to NLRP3 using a well-fitting mode. It is found that compound 22 will be a novel anti-inflammatory agent to treat inflammatory diseases with an improved safety profile.