Discovery of novel pyrazole derivatives as a potent anti-inflammatory agent in RAW264.7 cells via inhibition of NF-ĸB for possible benefit against SARS-CoV-2.

Due to unavailability of a specific drug/vaccine to attenuate severe acute respiratory syndrome coronavirus 2, the current strategy to combat the infection has been largely dependent upon the use of anti-inflammatory drugs to control cytokines storm responsible for respiratory depression. Thus, in this study, we discovered novel pyrazole analogs as a potent nuclear factor kappa B (NF-ĸB) inhibitor. The compounds were assessed for NF-ĸB transcriptional inhibitory activity in RAW264.7 cells after stimulation with lipopolysaccharides (LPS), revealing Compound 6c as the most potent analog among the tested series. The effect of Compound 6c was further investigated on the levels of interleukin-1β, tumor necrosis factor-α, and interleukin-6 in LPS-stimulated RAW267.4 cells by enzyme immunoassay, where it causes a significant reduction in the level of these cytokines. In Western blot analysis, Compound 6c also causes the inhibition of inhibitor kappa B-α and NF-κB. It was found to be snugly fitted into the inner grove of the active site of NF-ĸB by forming H-bonds and a nonbonded interaction with Asn28 in a docking analysis.