Anti-inflammatory effect of water extracts obtained from doenjang in LPS-stimulated RAW 264.7 cells

The effect of water extracts of doenjang (WED) on cyclooxygenase pathway and cytokine production in lipopolysaccharide (LPS)-treated RAW 264.7 macrophage cells was investigated. WED was fractionated by ultrafiltration into five individual groups of molecular weights. All of the WED fractions significantly inhibited the production of prostaglandin E-2 (PGE(2)) and expression of cyclooxygenase-2 (COX-2) in LPS-stimulated RAW 264.7 macrophages. Furthermore, each of the WED fractions significantly decreased production of pro-inflammatory cytokine such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) (p<0.05). The fraction between 10 to 30 kDa of WED showed the highest inhibition of pro-inflammatory cytokine production, LPS-induced COX-2 expression and PEG(2) production. These results suggest that WED fractions may have the anti-inflammatory effect via the stimulus of COX-2 and TNF-alpha in LPS-stimulated inflammation in RAW 264.7 cells.