Salvianolic acid A suppress lipopolysaccharide-induced NF-κB signaling pathway by targeting IKKβ

Salvianolic acid A. an active compound present in Salvia miltiorrhiza, is a phenolic carboxylic acid derivative, ((2R)-3-(3,4-Dihydroxyphenyl)-2-[(E)-3-[2-RE)-2-(3,4-dihydroxyphenyl) ethenyl]-3,4-dihydroxyphenyl] prop-2-enoyl]oxypropanoic acid). The present study was performed to investigate the underlying mechanisms of anti-inflammatory effects with salvianolic acid A. specially focused on nuclear factor kappa B (NF-kappa B) signaling pathway by targeting the I kappa B kinase beta (IKK beta). The effect of salvianolic acid A for IKK beta activity was analyzed using an immobilized metal affinity for phosphochemicals (IMAP)-based time-resolved fluorescence resonance energy transfer (TR-FRET) assay. The underlying mechanisms of salvianolic acid A were examined using lipopolysaccharide (LPS)-stimulated RAW264.7 cells. IKK beta studies based on IMAP-TR-FRET showed that salvianolic acid A possesses a potent IKK beta inhibitory activity with Ki value of 3.63 mu M in an ATP-noncompetitive manner. Pretreatment with salvianolic acid A (10, 30 mu M) decreased LPS-induced expression of iNOS and COX-2, thereby inhibiting production of nitric oxide and prostaglandin E-2, respectively. In addition, salvianolic acid A (10,30 mu M) also attenuated the LPS-induced I kappa B alpha phosphorylation and degradation, and NF-kappa B translocation. These results suggest that salvianolic acid A modulates NF-kappa B-dependent inflammatory pathways through IKK beta inhibition and these anti-inflammatory effects will aid in understanding the pharmacology and mode of action of salvianolic acid A. (C) 2011 Elsevier B.V. All rights reserved.