Polyphenols from Cymbopogon citratus inhibit iNOS expression and NO production – a promising source of new anti-inflammatory drugs
Inflammation is known to be associated with several pathologies, and due to the side effects of the current anti-inflammatory drugs there is an urgent need to find safer compounds. The inhibition of production of the inflammatory mediator nitric oxide (NO) has been used as a strategy to develop new anti-inflammatory drugs. Cymbopogon citratus (Cy) is used in traditional medicine to treat inflammation, diabetes and other health problems, but little is known about its mechanism of action. In a previous report, we demonstrated that Cy has strong antioxidant activity related to its polyphenolic content . In the present study we evaluated the anti-inflammatory action of polyphenolic fractions (PFs) from a lipid- and essential oil-free infusion of Cc leaves, analyzing the NO production, the NO synthase (iNOS) expression and mitogen activated protein kinases (MAPKs) activation, in the mouse macrophage cell line Raw264.7. We observed that PFs inhibited the NO production and iNOS expression induced by the strong inflammatory stimulus lipopolysaccharide, but did not affect the LPS-mediated MAPKs activation. The acid phenolics and tannins were the principal polyphenols responsible for the in vitro Cy anti-inflammatory activity. In conclusion, the polyphenols isolated from Cymbopogon citratus have anti-inflammatory activity and these compounds can be a promising natural source of new anti-inflammatory drugs.
Acknowledgements: FCT and POFC/FEDER for financial support. Research supported by FCT PhD fellowships SFRH/BD/41283/2007 and SFRH/BD/46281/2008 and the project FCOMP-01–0124-FEDER-011096 (ref FCT PTDC/SAU-FCF/105429/2008).
References: 1. Figueirinha, A. et al. (2008) Food Chem 110: 718–728.