Anti-inflammatory effects of Juncus effusus extract (JEE) on LPS-stimulated RAW 264.7 cells and edema models

Abstract

Context: Juncus effusus L. var. decipiens BUCHEN. f. leschenaultii GAY has been used in traditional medicine for the treatment of anxiety and insomnia.Objective: The objective of this study was to evaluate the effects of ethanol extract from the pith of Juncus effusus (JEE) on anti-inflammatory activities in RAW 264.7 cells.Materials and methods: The production of inflammatory mediators and the underlying mechanisms using 3.1, 6.3, and 12.5 μg/mL concentrations of JEE were investigated. In addition, the topical anti-inflammatory effects of JEE (0.5, 1, and 2 mg/mL) on 12-O-tetradecanoylphorobol-13 acetate (TPA)-induced ear edema and oral administration of JEE (50, 100, and 200 mg/kg) on carrageenan-induced paw-edema were studied in mice.Results: JEE reduced the release of nitric oxide (NO, IC50 value = 1.98 μg/mL), prostaglandin E2 (IC50 value = 5.5 μg/mL), and pro-inflammatory cytokines, IL-1β (IC50 value = 4.74 μg/mL) and IL-6 (IC50 value = 20.48 μg/mL). JEE also suppressed the protein expression of inducible NO synthase and cyclooxygenase-2 in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Mechanism studies showed attenuation of LPS-induced activation of NF-κB by JEE via abrogation of IκBα degradation and a subsequent decrease in nuclear p65 level. Phosphorylation of all three MAP kinases (ERK, JNK, and p38) in LPS-stimulated RAW 264.7 cells was also suppressed in a dose-dependent manner. In acute inflammation models of mice, topical application (1 and 2 mg) and oral administration (50, 100, and 200 mg/kg) of JEE ameliorated TPA-induced ear edema and carrageenan-induced paw edema, respectively, in dose-dependent manners.Discussion and conclusion: These results indicate that JEE exhibited anti-inflammatory activities by suppressing the production of inflammatory mediators in LPS-stimulated RAW 264.7 cells and by attenuating edema in mice.