Binding of rosmarinic acid curcumin and capsaicin with PLA2: A comparative study

Phospholipase A2 (PLA2) is a key enzyme involved in the formation of pro-inflammatory mediators like eicosanoids. Inhibition of PLA2 is regarded as one of the effective methods of controlling inflammation. The present study investigated the binding potentials of three natural compounds, rosmarinic acid (RA), capsaicin (CAP), and curcumin (CUR) by means of in silico and in vitro methods. Our study revealed that RA has relatively better binding affinity and inhibition potentials when compared to the other two molecules. Our ITC experiments were also suggested a slightly better binding energy for the RA. The stoichiometry of the protein ligand complex obtained from one of the ITC experiments suggested the possibilities of binding of a small molecule MCW (degraded product of CUR) on PLA2. Overall study demonstrated that the anti-inflammatory activity of RA, CUR and CAP may be partly due to the inhibition of PLA2.