Fermentation by Lactobacillus enhances anti-inflammatory effect of Oyaksungisan on LPS-stimulated RAW 264.7 mouse macrophage cells

BACKGROUND: Oyaksungisan (OY) has been used as a traditional drug in east-Asian countries. However, its effect on inflammation still remains unknown. In this study, to provide insight into the biological effects of OY and OY fermented by Lactobacillus, we investigated their effects on lipopolysaccharide (LPS)-mediated inflammation in the RAW 264.7 murine macrophage cells. METHODS: The investigation was focused on whether OY and fermented OYs could inhibit the production of pro-inflammatory mediators such as nitric oxide (NO) and prostaglandin (PG) E(2 )as well as the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-α, interleukin (IL)-6, nuclear factor (NF)-κB and mitogen-activated protein kinases (MAPKs) in LPS-stimulated RAW 264.7 cells. RESULTS: We found that OY inhibits a little LPS-induced NO, PGE(2), TNF-α and IL-6 productions as well as the expressions of iNOS and COX-2. Interestingly, the fermentation significantly increased its inhibitory effect on the expression of all pro-inflammatory mediators. Furthermore, the fermented OYs exhibited elevated inhibition on the translocation of NF-κB p65 through reduced IκBα degradation as well as the phosphorylations of extracellular signal-regulated kinase (ERK), p38 and c-Jun NH(2)-terminal kinase (JNK) MAPKs than untreated control or original OY. CONCLUSIONS: Finally, the fermentation by Lactobacillus potentiates the anti-inflammatory effect of OY by inhibiting NF-κB and MAPK activity in the macrophage cells.