Suppressive effects of Lithospermum erythrorhizon extracts on lipopolysaccharide-induced activation of AM and NF-κB via mitogen-activated protein kinase pathways in mouse macrophage cells

A variety of anti-inflammatory agents have been shown to exert chemopreventive activity via targeting of transcription factors such as NF-kappa B and AP-1. Lithospermum erythrorhizon (LE) has long been used in traditional oriental medicine. In this study, we demonstrated the inhibitory effects of LE extracts on lipopolysaccharide (LPS)-stimulated production of inflammatory cytokines. As an undedying mechanism of inhibition, LE extracts reduced LPS-induced transactivation of AP-1 as well as NF-kappa B in mouse macrophage cells. Electrophoretic mobility shift assays indicated that LE extracts inhibited the DNA binding activities of AP-1 and NF-kappa B. In addition, phosphorylation of licB-a protein was suppressed by LE extracts. Moreover, LE extracts inhibited c-Jun N-terminal kinase and extracellular signal-regulated signaling pathways. Our results suggest that the anti-inflammatory activity of LE extracts may be mediated by the inhibition of signal transduction pathways that normally lead to the activation of AP-1 and NF-kappa B. These inhibitory effects may be useful for chemoprevention of cancer or other chronic inflammatory diseases.