Aqueous extract of Lycii fructus suppresses inflammation through the inhibition of nuclear factor kappa B signal pathway in murine raw 264.7 macrophages

Abstract

Lycii fructus is the fruit of Lycium chinense Miller and is part of the Solanaceae family. Lycii fructus produces various effects such as hypotensive, hypoglycemic, anti-pyretic, and anti-stress activities. Lycii fructus is known to contain betaine, carotene, nicotinic acid, zeaxanthin, and cerebroside. In the present study, the effects of Lycii fructus aqueous extract on lipopolysaccharide (LPS)-induced inflammation in murine raw 264.7 macrophage cells were investigated. In this study we utilized the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, reverse transcriptionpolymerase chain reaction (RT-PCR), Western blotting, and nitric oxide (NO) detection. Lycii fructus aqueous extract suppressed NO production by inhibiting the LPS-induced expressions of inducible nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-<TEX>$\alpha$</TEX>) mRNA and iNOS protein in murine raw 264.7 macrophage cells. Also, Lycii fructus aqueous extract suppressed the activation of nuclear factor-kappa B (NF-<TEX>${\kappa}B$</TEX>) in the nucleus. These results demonstrated that Lycii fructus aqueous extract causes an anti-inflammatory effect that was likely produced by the suppression of iNOS expression through the down-regulation of NF-<TEX>$\hat{e}B$</TEX> binding activity.