Synthesis and Evaluation of Bakuchiol Derivatives as Potent Anti-inflammatory Agents in Vitro and in Vivo

Bakuchiol, a prenylated phenolic monoterpene derived from the fruit of Psoralen corylifolia L. (Buguzhi), is widely used to treat tumors, viruses, inflammation, and bacterial infections. In this study, we designed and synthesized 30 bakuchiol derivatives to identify new anti-inflammatory drugs. The anti-inflammatory activities of the derivatives were screened using lipopolysaccharide-induced RAW264.7 cells. To evaluate the anti-inflammatory activity of the compounds, we measured nitric oxide (NO), interleukin-6, and tumor necrosis factor-α production. Based on the screening results, compound 7a displayed more pronounced activity than bakuchiol and celecoxib. Furthermore, the mechanistic studies indicated that 7a inhibited pro-inflammatory cytokine release, which was correlated with activation of the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 signaling pathway and blockade of the nuclear factor-κB/mitogen-activated protein kinase signaling pathway. The in vivo anti-inflammatory activity in zebrafish indicated that 7a inhibited NO and reactive oxygen species production in a dose-dependent manner. These results indicate that 7a is a potential candidate for development as an anti-inflammatory agent.