Auranofin (SKF-39162) is a thioredoxin reductase (TrxR) inhibitor with an IC₅₀ of 0.2 μM. IC50 & Target: IC50: 0.2 μM (TrxR)^[1] In Vitro: Auranofin is a drug that is approved for the treatment of rheumatoid arthritis but is being investigated for potential therapeutic application in a number of other diseases including cancer, neurodegenerative disorders. Auranofin induces apoptosis in cells through a Bax/Bak-dependent mechanism associated with selective disruption of mitochondrial redox homeostasis in conjunction with oxidation of Prx3^[1]. Auranofin inhibits proliferation and survival of SKOV3 cells in a dose- and time-dependent manner. Auranofin treatment activates the pro-apoptotic caspase-3, increases protein levels of apoptosis-inducing proteins Bax and Bim and reduces the expression of the anti-apoptotic mediator Bcl-2 in SKOV3 cells^[2]. Auranofin is a lipophilic gold compound with anti-inflammatory and immunosuppressive properties. Auranofin inhibits the cell growth and induction of mitochondrial apoptosis in PC3 human prostate cancer cells. Treatment with auranofin significantly inhibits cell viability with an IC₅₀ value of 2.5 μM after 24 h^[3]. In Vivo: Prophylactic treatment of adjuvant-induced arthritis rats with auranofin results in a slight reduction in paw edema, a complete normalization of the depressed IL-2 production, and a reduction of the elevated IL-1 production, but has no effect on the depressed IL-3 production^[4].