Extract of buckwheat sprouts scavenges oxidation and inhibits pro-inflammatory mediators in lipopolysaccharide-stimulated macrophages (RAW264.7)

Abstract

OBJECTIVE: Buckwheat has been considered as a potential source of nutraceutical components on the world market of probiotic foodstuffs. The purpose of this study was to evaluate the effects of tartary buckwheat (Fagopyrum tataricum) sprouts on oxidation and pro-inflammatory mediators. METHODS: The anti-oxidant effects of buckwheat extract (BWE) and rutin were evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH)- and nitric oxide (NO)-scavenging activities, serum peroxidation and chelating assays. Lipopolysaccharide (LPS)-stimulated RAW264.7 cells were used to evaluate anti-inflammatory activities of buckwheat and rutin. NO production in LPSstimulated RAW264.7 cells was determined by using Griess reagent. The expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), nuclear factor-kappa B (NF-κB) p65 subunit in cytosolic and nuclear portions were determined by Western blot analysis. Also, the production of inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) was determined by enzyme-linked immunosorbent assay. RESULTS: Inhibitory concentration 50 values for DPPH- and NO-scavenging activities of BWE were 24.97 and 72.54 μg/mL respectively. BWE inhibited serum oxidation and possessed chelating activity. Furthermore, BWE inhibited IL-6 and TNF-α production in LPS-stimulated RAW264.7 cells. Also, BWE inhibited iNOS and COX-2 expression and NF-κB p65 translocation. CONCLUSION: Buckwheat sprouts possessed strong antioxidant activity and inhibited production of pro-inflammatory mediators in the applied model systems. Thus, buckwheat can be suggested to be beneficial in inflammatory diseases by inhibiting the free radicals and inflammatory mediators. © 2013 Rajendra Karki et al.