Inhibitory effects of Lepidium sativum polysaccharide extracts on TNF-α production in Escherichia coli -stimulated mouse

The present study was designed to study the quantitative effects of extraction time, temperature and solvent to sample ratio on the yield of Lepidium sativum polysaccharides (LSP) using a Box–Behnken design. The activities of the optimized LSP extract were then tested in an in vivo experimental system of Escherichia coli (E. coli)-induced endotoxin shock. The optimal polysaccharide extraction conditions were established by the equation of regression and evaluation of the response surface contour plots: extraction time 5.2 h; temperature 95 °C and ratio of water to raw material 31.89 mL/g. Subsequently, an in vivo endotoxin shock was induced in mice with a single E. coli i.p. injection. Septic mice showed a substantial raise in the levels of tumor necrosis factor alpha (TNF-α) in plasma, whereas mice treated with LSP after E. coli injection showed considerable lower plasma levels of TNF-α (P < 0.05). These results suggest that LSP have beneficial effects when administered to mice with endotoxin shock by diminishing the pro-inflammatory response. The systemic activity of LSP indicated that the extract has a significant inhibitory effect against E. coli-induced inflammation by reducing the circulating levels of TNF-α. Further studies are warranted to explore the clinical implications of such observations.