Design and synthesis novel di-carbonyl analogs of curcumin (DACs) act as potent anti-inflammatory agents against LPS-induced acute lung injury (ALI)

A novel series of di-carbonyl analogs of curcumin (DACs) were prepared and evaluated for their anti-inflammatory properties. Preliminary results showed that a vast majority of compounds tested in this study could effectively suppress LPS-induced production of tumor necrosis factor (TNF)-α and interleukin (IL)-6. Structure-activity relationships of the compounds were discussed. Compounds 5a27 and 5a28 showed the most potent anti-inflammatory activities and had higher structural stability and orally bioavailability than curcumin in vitro. Mechanistically, they inhibited the activation of macrophages via the blockade of mitogen-activated protein kinase (MAPK) signaling and nuclear translocation of NF-κB. In vivo, 5a27 and 5a28 markedly alleviated lipopolysaccharides (LPS)-induced acute lung injury (ALI). The wet/dry ratio of lungs was significantly normalized by the active compounds, which was consistent with the suppression of neutrophil infiltration and production of proinflammatory cytokines. Collectively, these results present a new series of curcumin analogs as promising anti-inflammatory agents for treatment of ALI.