SR-31747 free base is an immunosuppressive and anti-inflammatory sigma ligand that efficiently inhibits cell proliferation through the inhibition of sterol isomerase activity.

SR-31747 blocks the proliferation of lymphocytes at a concentration of 10 nM. SR-31747 is capable of inhibiting T-cell proliferation when added as late as 24 h after activation. SR-31747 arrests proliferation in yeast cells in a dose-dependent manner[2].

In vivo, SR-31747 dramatically blocks lipopolysaccharide-induced production of IL-1, IL-6 and TNF-α in a dose-dependent manner (ED 50 , 2 mg/kg). SR-31747 probably abrogated monokine production through an indirect mechanism that involves endogenous corticosteroids. This conclusion was supported by in vivo experiments that shows that: 1) ablation of corticosteroids by use of Mifepristone or adrenalectomy suppress the effect of SR-31747; 2) administration of SR-31747 induces an enhancement of the corticosterone level. SR-31747 improves the survival of animals with endotoxinic shock as a result of monokine inhibition[1].