Anti-inflammatory properties of polyphenols from Cymbopogon citratus by inhibition of NF-κB pathway

Inflammation is associated with several diseases and still exits an urgent need for the development of new and safer anti-inflammatory drugs. Since plant polyphenols are described to possess anti-inflammatory properties through modulation of pro-inflammatory signaling pathways, they could be used as source of a new anti-inflammatory drug. In a previous study using Cymbopogon citratus Stapf (Cy), an herb used in traditional medicine, we have demonstrated that polyphenolic compounds (PFs) from Cy have anti-inflammatory properties by inhibiting lipopolysaccharide (LPS)-triggered nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression [1]. To further understand the underlying molecular mechanisms of PFs activity, the effect of Cy polyphenolic fractions was evaluated on the LPS-induced nuclear factor (NF)-κB pathway in the mouse macrophage cell line Raw 264.7. In Western blot assays, we observed that PFs inhibited the degradation and phosphorylation of inhibitory protein-κB (IκB). Next, the NF-κB transcriptional activity was assessed using cells transiently transfected with a NF-κB-dependent luciferase reporter plasmid. In addition to the interference with LPS-induced NF-κB activation observed in western blot, PFs inhibited the LPS-induced NF-κB transcriptional activity. In summary, these results demonstrate that PFs from Cymbopogon citratus inhibited the NF-κB pathway and therefore could be used as a natural anti-inflammatory drug.

Keywords: Anti-inflammatory, Cymbopogon citratus, polyphenols, NF-kB

Acknowledgement: Research supported by FCT PhD fellowship SFRH/BD/46281/2008, FCT project PTDC/SAU-FCF/105429/2008 and FEDER/COMPETE (FCOMP-01–0124-FEDER-011096).

References: 1. Francisco V et al. (2011)J Ethnopharmacol 133: 818–827