Protective effect of lactoferrin against LPS-induced endotoxemia is mediated by IL-10

The aim of this study was to investigate the mechanism by which lactoferrin (LF) protects against development of LPS-induced endotoxemia in mice. CBA mice were given 5 mg bovine LF intravenously (i.v.) or per os 24 hr prior to i.v. injection of 50 mu g LPS. Two hours after LPS injection mice were bled and serum levels of TNF-alpha, IL-6 and IL-10 were determined. The results showed that LF alone given i.v. or per os increased the production of TNF-alpha, IL-6 and IL-10 to various degrees. Mice treated with LF 24 hr before LPS injection showed a significantly reduced release of TNF-alpha, and to lesser degree IL-6 and IL-10. The protective effect of LF against development of LPS-induced endotoxemia was associated with a significant increase of the IL-10 to TNF-alpha ratio.