Anti-inflammatory activity of Cymbopogon citratus leaf infusion in lipopolysaccharide-stimulated dendritic cells: contribution of the polyphenols.
Cymbopogon citratus, an herb known worldwide as lemongrass, is widely consumed as an aromatic drink, and its fresh and dried leaves are currently used in traditional cuisine. However, little is known about the mechanism of action of C. citratus, namely, the anti-inflammatory effects of its dietary components. Because nitric oxide (NO), produced in large quantities by activated inflammatory cells, has been demonstrated to be involved in the pathogenesis of acute and chronic inflammation, we evaluated the effects of the infusion of dried leaves from C. citratus, as well as its polyphenolic fractions--flavonoid-, tannin-, and phenolic acid-rich fractions (FF, TF, and PAF, respectively)--on the NO production induced by lipopolysaccharide (LPS) in a skin-derived dendritic cell line (FSDC). C. citratus infusion significantly inhibited the LPS-induced NO production and inducible NO synthase (iNOS) protein expression. All the polyphenolic fractions tested also reduced the iNOS protein levels and NO production stimulated by LPS in FSDC cells, without affecting cell viability, with the strongest effects being observed for the fractions with mono- and polymeric flavonoids (FF and TF, respectively). Our results also indicated that the anti-inflammatory properties of FF are mainly due to luteolin glycosides. In conclusion, C. citratus has NO scavenging activity and inhibits iNOS expression and should be explored for the treatment of inflammatory diseases, in particular of the gastrointestinal tract.
Figueirinha
Artur
A
Centros de Estudos Farmacêuticos, Universidade de Coimbra, Coimbra, Portugal.
Cruz
Maria Teresa
MT
Francisco
Vera
V
Lopes
M Celeste
MC
Batista
Maria Teresa
MT
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000032:analysis / Q000276:immunology* / Q000302:isolation & purification / Q000494:pharmacology; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D031743:Cymbopogon / Q000737:chemistry* / Q000276:immunology; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology*; D005419:Flavonoids / Q000032:analysis / Q000276:immunology* / Q000302:isolation & purification; D008070:Lipopolysaccharides / Q000276:immunology*; D051379:Mice; D009569:Nitric Oxide / Q000276:immunology; D010636:Phenols / Q000032:analysis / Q000276:immunology* / Q000302:isolation & purification; D010936:Plant Extracts / Q000032:analysis / Q000276:immunology* / Q000302:isolation & purification / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry / Q000276:immunology; D059808:Polyphenols
D000893:Anti-Inflammatory Agents; D005419:Flavonoids; D008070:Lipopolysaccharides; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; D009569:Nitric Oxide