Iguratimod

A novel disease-modifying antirheumatic drug that inhibits NF-kappaB (NF-κB) p65 subunit (RelA) phosphorylation and nuclear translocation without affecting IKBα degradation; inhibits LPS-stimulated production of TNF-α, IL-6, and IL-8 with decreasing mRNA levels (IL-6 and IL-8); mainly targets Act1 to disrupt the interaction between Act1 and TRAF5 and IKKi in the IL-17 pathway of synoviocytes; also exhibts selective MIF inhibition in vitro and in vivo.Rheumatoid Arthritis Approved(In Vitro):Iguratimod (T-614) is an antirheumatic agent, acts as an inhibitor of COX-2, with an IC50 of 20 μM (7.7 μg/mL), but shows no effect on COX-1. Iguratimod (0.1, 1, 10 μg/mL) inhibits bradykinin-stimulated PGE2 release from fibroblasts. Iguratimod suppresses the COX activity from bradykinin stimulated fibroblasts in a concentration-dependent manner, with an IC50 of 48 μg/mL. Iguratimod (10 and 30 μg/mL) also dose-dependently inhibits COX-2 mRNA levels. In addition, Iguratimod potently inhibits macrophage migration inhibitory factor (MIF) with an IC50 of 6.81 μM. Iguratimod is synergetic with glucocorticoids in vitro.\n(In Vivo):Iguratimod (5 or 20 mg/kg) shows analgesic effect, significantly improves the pain withdrawal threshold of the left hind paw in dose-dependent manner in rats. Iguratimod (5 or 20 mg/kg) reduces the elevation of pERK1/2 and c-Fos in the spinal cord induced by cancer cell inoculation. Iguratimod also dose-dependently decreases the IL-6 levels in rats. In Iguratimod-treated rats, the activity of osteoclasts is weaker than the control group. Iguratimod (20 mg/kg i.p.) shows significantly increased survival in BALB/c mice that are vulnerable to endotoxemia, and attenuates TNFα release measured in serum isolated 90 min post-LPS administration in wild-type C57BL/6 mice.