Amorfrutin A inhibits TNF-α-induced NF-κB activation and NF-κB-regulated target gene products

The nuclear factor-κB (NF-κB) transcription factors control many physiological processes including inflammation, immunity, apoptosis, and angiogenesis. In our search for NF-κB inhibitors from natural resources, we identified amorfrutin A as an inhibitor of NF-κB activation from the fruits of Amorpha fruticosa L. In present study, this compound significantly inhibited the TNF-α-induced expression of NF-κB reporter gene. Further analysis revealed that amorfrutin A was a potent inhibitor of NF-κB activation by the suppression of TNF-α-induced inhibitor of κBα (IκBα) degradation, p65 nuclear translocation, and DNA-binding activity of NF-κB. We also demonstrated that pretreatment of cells with this compound prevented the TNF-α-induced expression of NF-κB target genes, such as antiapoptosis (cIAP-1 and FLIP), proliferation (COX-2 and cyclinD1), invasion (MMP-9), angiogenesis (VEGF), and major inflammatory cytokines (TNF-α, IL-8, and MCP1). Furthermore, our results suggest that amorfrutin A potentiates TNF-α-induced apoptosis. Taken together, amorfrutin A could be a valuable candidate for the intervention of NF-κB-dependent pathological conditions such as inflammation.