NCI 126224

NCI 126224, a toll-like receptor 4 (TLR4) antagonist, demonstrates selective inhibition of nitric oxide (NO) production in RAW 264.7 macrophages, triggered by the TLR4 agonist LPS (IC50 = 0.31 μM), as opposed to minimal effects on NO production induced by agonists for TLR7/8 (R-848), TLR1/2 (Pam3CSK4), and TLR3 (poly (I:C) ) . Nevertheless, it also effectively inhibits NO production initiated by the TLR2/6 agonist FSL-1 at an IC50 of 0.6 μM in the same cell line. Moreover, NCI 126224 suppresses LPS-induced NF-κB activity in BV-2 microglial cells and reduces LPS-triggered increases in IL-1β and TNF-α levels in RAW 264.7 macrophages with IC50 values of 5.92, 0.42, and 1.54 μM, respectively.