Anti-inflammatory and immune-modulating effect of Ulmus davidiana var. japonica Nakai extract on a macrophage cell line and immune cells in the mouse small intestine

Abstract

Ethnopharmacological relevanceTraditional Oriental medicine has utilized the barks of the stem and root of Ulmus davidiana var. japonica Nakai (UD) to treat inflammatory disorders. Aim of the studyThe purpose of the present study was to evaluate UD's anti-inflammatory and immune-modulating effects on a lipopolysaccharide (LPS)-stimulated macrophage cell line and small-intestinal lamina propria (LP) cells, respectively. Materials and methodsRAW 264.7 cells were stimulated with LPS in the presence of various concentrations of a UD water-soluble extract. Cell viability, nitric oxide (NO) production, and the level of inflammatory cytokines synthesis were measured. Among the mice receiving the UD water-soluble extract, changes in the LP cell populations and immunoglobulin (Ig)A production were evaluated. ResultsThe UD water-soluble extract inhibited LPS-induced NO synthesis and inflammatory cytokine production in a RAW264.7 macrophage-like cell line. Small-intestinal LP cells isolated from mice that received the UD extract displayed a decrease in the side scatter of medium-to-high cells. Those LP cells isolated from the UD-treated mice also showed a marked decrease of intracellular IgA. However, UD administration had no apparent effect on the synthesis of systemic inflammatory cytokines. ConclusionsThese results suggest that UD water-soluble extracts have anti-inflammatory properties and, as such, can be used to promote intestinal immune-homeostatic conditions.