Background:The repertoire of immunomodulators that can be used for the treatment of inflammatory bowel disease is limited. The use of these drugs is further restricted by the occurrence of side effects in a proportion of patients. Miltefosine (hexadecylphosphocholine) is a lipid drug developed in the 1980s for the treatment of cancer but is nowadays best known for its application in the oral treatment of leishmaniasis. Although the exact mechanism of action of miltefosine has yet to be elucidated, the drug has previously been shown to inhibit phospholipases and protein kinase C, both key components of proproliferative signal transduction in T cells.Methods:Stimulated peripheral blood lymphocyte were treated with miltefosine, and proliferation was measured. We use the CD45RB(high) T-cell transfer colitis model to investigate the effect of miltefosine treatment on intestinal inflammation. Effects on the severity of colitis were studied by histochemical and immunohistochemical staining, and cytokine levels were determined using a cytokine bead array.Results:Miltefosine inhibited T-cell proliferation in vitro. In the transfer model, miltefosine significantly ameliorated the severity of colitis as measured by clinical, (immuno)histochemical, and biochemical parameters.Conclusions:Miltefosine inhibits T-cell proliferation and effectively reduces inflammation in the T-cell transfer model. The drug may therefore be a candidate immunomodulator for inflammatory bowel disease.