Korean Red Ginseng saponin fraction modulates radiation effects on lipopolysaccharide-stimulated nitric oxide production in RAW264.7 macrophage cells

BACKGROUND: In previous work, we reported that Korean Red Ginseng saponin fraction (RGSF) showed anti-inflammatory activities in vitro and in vivo. METHODS: The present study investigated the radioprotective properties of RGSF by examining its effects on ionizing radiation (IR)-enhanced and lipopolysaccharide (LPS)-mediated inflammatory responses in murine macrophage cells. RESULTS: RGSF induced strong downregulation of IR-enhanced and LPS-induced proinflammatory responses such as nitric oxide (NO) production (Inhibitory Concentration 50 (IC50) = 5.1 ± 0.8 μM) and interleukin-1β levels. RGSF was found to exert its radioprotective effects by inhibition of a signaling cascade that activated checkpoint kinase 2-nuclear factor-κB. In addition, RGSF strongly inhibited IR-enhanced LPS-induced expression of hemoxyganase-1, implying that the latter may be a potential target of RGSF. CONCLUSION: Taken together, our data suggest that RGSF can be considered and developed for use as an effective radioprotective agent with minimal adverse effects.