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 effectively inhibits lymphocyte proliferation at a concentration of 10 nM and can suppress T-cell proliferation even when introduced 24 hours post-activation. Additionally, it halts yeast cell proliferation in a dose-responsive manner [2].

In vivo experiments reveal that SR-31747 significantly inhibits the production of IL-1, IL-6, and TNF-α in response to lipopolysaccharide in a dose-dependent manner (ED50, 2 mg/kg). This inhibition is likely mediated through an indirect mechanism involving endogenous corticosteroids, as suggested by experiments demonstrating that the effects of SR-31747 are diminished by corticosteroid depletion using Mifepristone or adrenalectomy, and that SR-31747 administration elevates corticosterone levels. Consequently, SR-31747 enhances survival in animals facing endotoxic shock by dampening monokine production[1].