Immunomodulatory activity of sodium silicate containing selenium in LPS-stimulated immune cells

Selenium salts are toxic in large amounts, however, trace amounts are necessary for cellular function in many organisms, including all animals. Selenium is a component of the antioxidant enzymes glutathione peroxidase and thioredoxin reductase (which indirectly reduce certain oxidized molecules in animals and some plants). In addition, sodium silicate (Na2SiO3) possesses a number of biological activities, especially in improvement of cell growth. However, few studies on the effects of sodium silicate and selenium on an immune system have been reported so far. The objective of this experiment was to investigate the effect of soluble sodium silicate/Se on lipopolysaccharide (LPS)-induced inflammatory response in RAW264.7 cells. The production of nitric oxide (NO) and proinflammatory cytokines was examined in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The cells were cultured in Dulbecco's modified Eagle’s medium (DMEM). Concentration of 10 ppm or less of soluble sodium silicate/Se had no cytotoxic effect on RAW264.7 cells. The soluble sodium silicate/Se decreased LPS-induced production of NO but did not affect the levels of TNF-α, IL-2, and IFN-γ in RAW264.7 cells. In addition, the sodium silicate/Se induced up regulation of IL-1β level in a dose-dependent manner. These results suggest that the soluble sodium silicate/Se has a synergistic effect in down-regulation of inflammatory response in vitro. KCI Citation Count: 0