Synergistic Anti-inflammatory Effect of Rosmarinic Acid and Luteolin in Lipopolysaccharide-Stimulated RAW264.7 Macrophage Cells

摘要

The aim of this study was to investigate the synergistic anti-inflammatory effect of rosmarinic acid (RA) and luteolin from perilla (Perilla frutescens L.) leaves in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. A combination of RA and luteolin more strongly inhibited the production of nitric oxide (NO), inducible NOS (iNOS), prostaglandin E_2 (PGE_2), and COX-2 than higher concentrations of RA or luteolin alone in LPS-stimulated RAW264.7 macrophages. The combined RA and luteolin synergistically inhibited the production of pro-inflammatory cytokines, such as tumor necrosis factor-ct (TNF-alpha), interleukin-6 (IL-6), and interleukin-1beta (IL-1beta), in LPS-stimulated RAW264.7 macrophages. Furthermore, combined RA and luteolin more strongly suppressed NF-kB activation than RA or luteolin alone, by inhibiting the degradation of inhibitor of NF-kB (IkB)-alpha and nuclear translocation of the p65 subunit of NF-kB in LPS-stimulated RAW264.7 macrophages. Collectively, these results suggest that RA and luteolin in combination exhibit synergistic effects in suppression of LPS-induced inflammation in RAW264.7 macrophages.