Inhibition of Lipopolysaccharide-Induced iNOS, COX- 2, and TNF-&#945 Expression by Aqueous Extract of Orixa Japonica in RAW 264.7 Cells via Suppression of NF- kB Activity

Purpose: To investigate the anti-inflammatory effects of aqueous extract of Orixa japonica (AEOJ) in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells.Methods: The expression of mRNA and protein using RT-PCR and Western blot analysis was investigated. The level of nitric oxide (NO) production was analyzed using Griess reaction. Release of prostaglandin E2 (PGE2) and tumor necrosis factor- (TNF-) was determined using sandwich ELISA.Results: AEOJ potently inhibited the production of nitric oxide (NO), prostaglandin E2 (PGE2), and tumor necrosis factor- (TNF-) in LPS-stimulated RAW 264.7 cells. Consistent with these findings, AEOJ wasalso found to significantly reduce LPS-induced expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), and TNF- at the transcriptional level. Additionally, AEOJ attenuated LPSinducedNF-B activity via the inhibition of IB phosphorylation and degradation. It was also found that the NF-B inhibitor N-acetyl cysteine (NAC) attenuated LPS-induced gene expression of iNOS, COX-2,and TNF-. These results indicate that AEOJ attenuates LPS-induced inflammatory mediators such as NO, PGE2, and TNF- via suppression of NF-B activity.Conclusion: These results suggest that AEOJ has a potential activity to alleviate LPS-induced inflammation