Anti-inflammatory activity of hydrosols from Tetragonia tetragonoides in LPS-induced RAW 264.7 cells

The present study was performed to investigate the anti-inflammatory activity of Tetragonia tetragonoides hydrosols (TTH) and its underlying mechanism in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Gas chromatography (GC) coupled with mass spectrometry and retention index calculations showed that TTH were mainly composed of tetratetracontane (29.5 %), nonacosane (27.6 %), and oleamide (17.1 %). TTH significantly decreased the production of nitric oxide (NO), prostaglandin E2 (PGE2), interleukin (IL)-6, and IL-1β in LPS-stimulated RAW 264.7 cells. Consistent with these observations, TTH treatment decreased the protein expression levels of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). The molecular mechanism of its anti-inflammatory activity was found to be associated with inhibition of nuclear factor-kappa B (NF-κB) phosphorylation and nuclear translocation of NF-κB 65. Furthermore, TTH markedly suppressed the LPS-induced phosphorylation of mitogen-activated protein kinases (MAPKs). Taken together, these data indicate that TTH exerts an anti-inflammatory activity by inhibiting the NF-κB and MAPK signaling pathways in LPS-stimulated RAW 264.7 cells.