Smilax guianensis Vitman extract prevents LPS-induced inflammation by inhibiting the NF-κB pathway in RAW 264.7 cells

ABSTRACT

Nutraceutical treatments can reduce inflammation and prevent the development of inflammatory diseases. In this study, the anti-inflammatory effects of Smilax guianensis Vitman extract (SGE) were examined. SGE suppressed lipopolysaccharide (LPS)-mediated nitrite production in RAW 264.7 cells. SGE also prevented the LPS-induced expression of inducible nitric oxide synthase (iNOS) but not cyclooxygenase (COX)-2. Western blot analysis showed that SGE attenuated LPS-induced phosphorylation of IκB kinase, inhibitor of kappa B (IκB), and p65. Additionally, SGE inhibited LPS-induced IκB degradation in RAW 264.7 cells. Western blot analysis of the cytosolic and nuclear fractions, as well as immunofluorescence assay results, revealed that SGE suppressed LPS-induced p65 nuclear translocation in RAW 264.7 cells. Moreover, SGE reduced LPS-induced interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) mRNA expression and IL-1β and IL-6 protein expression in RAW 264.7 cells. Collectively, these results indicate that SGE suppresses the NF-κB signaling pathway and thereby inhibits the production of NO, IL-1β, and IL-6.