Assessment of binding affinity of major bioactive compounds from <i>Momordica charantia</i>, <i>Azadirachta indica</i>, <i>Nelumbo nucifera</i>, <i>Caesalpinia crista</i>, <i>Martynia annua</i> and <i>Erythrina variegate</i> to COX-2 receptor: an <i>in silico</i> study

In traditional medicine, potential anti-inflammatory and pain-relieving activity of <i>Momordica charantia, Azadirachta indica, Nelumbo nucifera, Caesalpinia crista, Martynia annua</i> and <i>Erythrina variegate</i> has been emphasized. In this study, we explored binding affinity of 36 bioactive compounds from these plants to cyclooxygenase-2 (COX-2) receptor using docking method. Six compounds namely, beta carotene, lycopene, lutein, momordicoside, rutin and azadirachtin showed excellent binding affinities (−10.29, −10.22, −10.03, −7.9, −8.81 and −7.88 kcal/mol, respectively) and stable interactions with COX-2 (greater than those of aspirin and diclofenac) and they were chosen for the molecular dynamics (MD) assessments done throughout a 100-ns time period. Based on the computed RMSD, RMSF, Rg, SASA and PCA, all ligands were found to form stable and adequate interactions with COX-2 protein; these findings were comparable to those of aspirin and diclofenac, indicating the potential inhibitory properties of these ligands on COX-2 protein. In addition, the toxicity of compounds was evaluated using Pred-hERG, Pred-Skin and ProTox-II. Since COX-2 inhibitors have been reported to activate the Nrf2 pathway, it is hypothesized that they may confer other health-promoting effects through triggering Nrf2 signaling.