Effects of Solvent-extracted Fractions from Salicornia herbacea on Anti-oxidative Activity and Lipopolysaccharide-induced NO Production in Murine Macrophage RAW264.7 Cells

Salicornia herbacea L. (Chenopodiaceae: S. herbacea) is a salt marsh plant, which has long been prescribed in traditional medicines for the treatment of intestinal ailments, nephropathy, and hepatitis in Oriental countries. In order to elucidate the mechanisms of this herb, we conducted an anti-oxidative activity, the inhibition of nitric oxide (NO) production, and the suppression of the pro-inflammatory cytokine genes, with the solvent-extracts of S. herbacea. We found that both ethyl acetate and n-butanol tractions showed potent anti-oxidative effects in comparison to other fractions using xanthine oxidase assay with $IC_{50}$ values of $66.0{\pm}0.5\;{\mu}g/ml$ and $82.5{\pm}3.8\;{\mu}g/ml$, respectively. In addition, both ethyl acetate and n-butanol fractions showed more electron donating activity (EDA) than other tractions, according to DPPH (2, 2-Diphenyl-lpicrylhydrazyl radical) assay. The EDA of ethyl acetate fraction ($IC_{50}$ values of $117.5{\pm}3.8\;{\mu}g/ml$) is more significant than that of n-butanol fraction ($IC_{50}$ values of $375.0{\pm}12.5\;{\mu}g/ml$). Among potential anti-oxidative tractions, ethyl acetate traction dose-dependently suppressed lipopolysaccharide (LPS, $0.1\;{\mu}g/ml$)-induced nitric oxide (NO) production in RAW264.7 cell, while n-butanol did not. As expected, ethyl acetate fraction suppressed the expression of inducible NO synthase (iNOS) in RAW264.7 cell stimulated by $0.1\;{\mu}g/ml$ of LPS. Moreover, the ethyl acetate traction suppressed the expression of interleukin-1 $(IL)-1{\beta}$ and granulocyte/macrophage colony-stimulating factor (GM-CSF) mRNA in LPS-stimulated RAW264.7 cells. Therefore, these results suggest that S. herbacea may have anti-oxidative and anti-inflammatory activities by modulating radical-induced toxicity and various pro-inflammatory responses.