Discovery of novel TLR4/MD-2 inhibitors: Receptor structure-based virtual screening studies and anti-inflammatory evaluation

In this study, a receptor structure-based virtual screening strategy was constructed using a computer-aided drug design. First, the compounds were filtered based on the Lipinski pentad and adsorption, distribution, metabolism, excretion, and toxicity profiles. Then, receptor structure-based pharmacophore models were constructed and screened. Finally, the in vitro toxicity and anti-inflammatory activities of hit compounds were initially evaluated to investigate their in vitro anti-inflammatory effects and mechanisms of action. The results revealed that hit 94 had the best anti-inflammatory activity and low toxicity while inhibiting the activation of Toll-like receptor (TLR) 4/myeloid differentiation factor 2 (MD2)-associated signaling pathways of nuclear factor-xB and mitogen-activated protein kinase. In vivo adjuvant arthritis results also revealed that hit 94 ameliorated foot swelling to a greater extent in rats compared with the positive control drug indomethacin. These results suggest that hit 94 can be used as a potential TLR/MD2 inhibitor for inflammatory diseases.