The Anti-inflammatory Effect of Nypa fruticans Wurmb. Fruit on Lipopolysaccharide-induced Inflammatory response on RAW 264.7 cells

Objective : Nypa fruticans Wurmb. Fruit (NF) has been used as a conventional medicine to treat inflammatory peridontal diseases in Myanmar and Eastern Asia. However, the anti-inflammatory effect of NF aqueous extract on lipopolysaccharide (LPS)-induced inflammatory responses was not well-investigated. Therefore, this study was aimed to investigate the anti-inflammatory effect of NF on LPS-induced inflammatory responses on RAW 264.7 cells.Methods : To induce inflammation on the macrophage cell line, RAW 264.7 cells were treated with 500 ng/mL of LPS. Water extracts of NF was treated 1 h prior to treatment of LPS. Cell viability was measured by MTT assay. Production of nitrite was measured with Griess assay and pro-inflammatory cytokines such as interleukine (IL)-1β and IL-6, and tumor necrosis factor (TNF)-α was measured by enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (PCR). In addition, we examined the inhibitory mechanisms of NF by western blot and immunocytochemistry.Result : Water Extract from NF itself did not have any cytotoxic effect at the concentration of 200 ㎍/ml in RAW 264.7 cells. Treatment of NF inhibited the production of nitrite, and pro-inflammatory cytokines inlcuding IL-1β, IL-6 and TNF-α in a dose dependant. In addition, NF treatment inhibited the LPS-induced activation and translocation of nuclear factor (NF)-κB.Conclusion : In summary, our result suggest that treatment of NF could reduce the LPS-induced inflammatory responses via deactivation of NF-κB. This study could suggest that NF could be a beneficial drug or agent to prevent inflammation.